From 8099510e72e99be83adf43e9f067e280ed8fea03 Mon Sep 17 00:00:00 2001
From: checkraisefold <checkraisefold@crf.gay>
Date: Tue, 24 Sep 2024 17:05:44 -0700
Subject: [PATCH 01/17] Fix linking for symbols starting with ?

---
 compiler/rustc_codegen_ssa/src/back/symbol_export.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/compiler/rustc_codegen_ssa/src/back/symbol_export.rs b/compiler/rustc_codegen_ssa/src/back/symbol_export.rs
index 60ab291935256..25723dd1a5824 100644
--- a/compiler/rustc_codegen_ssa/src/back/symbol_export.rs
+++ b/compiler/rustc_codegen_ssa/src/back/symbol_export.rs
@@ -577,6 +577,7 @@ pub(crate) fn linking_symbol_name_for_instance_in_crate<'tcx>(
     }
 
     let prefix = match &target.arch[..] {
+        "x86" if target.is_like_windows && undecorated.starts_with("?") => return undecorated,
         "x86" => Some('_'),
         "x86_64" => None,
         "arm64ec" => Some('#'),

From 784d47b7d188058e82f465fe4018fcba55041e21 Mon Sep 17 00:00:00 2001
From: checkraisefold <checkraisefold@crf.gay>
Date: Mon, 30 Dec 2024 21:30:29 -0800
Subject: [PATCH 02/17] Add a test

---
 .../run-make/issue-44282-questionmark-mangle/main.rs  | 11 +++++++++++
 .../run-make/issue-44282-questionmark-mangle/rmake.rs |  9 +++++++++
 2 files changed, 20 insertions(+)
 create mode 100644 tests/run-make/issue-44282-questionmark-mangle/main.rs
 create mode 100644 tests/run-make/issue-44282-questionmark-mangle/rmake.rs

diff --git a/tests/run-make/issue-44282-questionmark-mangle/main.rs b/tests/run-make/issue-44282-questionmark-mangle/main.rs
new file mode 100644
index 0000000000000..d6df6b6133e17
--- /dev/null
+++ b/tests/run-make/issue-44282-questionmark-mangle/main.rs
@@ -0,0 +1,11 @@
+#![crate_type = "cdylib"]
+
+#[no_mangle]
+pub extern "C" fn foo(a: i32, b: i32) -> i32 {
+    1
+}
+
+#[export_name = "?bar@@YAXXZ"]
+pub extern "C" fn bar(a: i32, b: i32) -> i32 {
+    2
+}
diff --git a/tests/run-make/issue-44282-questionmark-mangle/rmake.rs b/tests/run-make/issue-44282-questionmark-mangle/rmake.rs
new file mode 100644
index 0000000000000..2fb91ef736f63
--- /dev/null
+++ b/tests/run-make/issue-44282-questionmark-mangle/rmake.rs
@@ -0,0 +1,9 @@
+// This test verifies that functions including a leading question mark
+// in their export_name attribute successfully compile.
+// This is only an issue on Windows 32-bit.
+
+use run_make_support::{run, run_fail, rustc};
+
+fn main() {
+    rustc().input("main.rs").target("i686-pc-windows-msvc").run();
+}

From a4c628c753e9ac5310f045cc6893baf353859158 Mon Sep 17 00:00:00 2001
From: checkraisefold <checkraisefold@crf.gay>
Date: Tue, 31 Dec 2024 00:29:52 -0800
Subject: [PATCH 03/17] Significant test improvements

---
 .../issue-44282-questionmark-mangle/main.rs   | 11 --------
 .../issue-44282-questionmark-mangle/rmake.rs  |  9 -------
 .../symbol-with-question-mark-links.rs        | 25 +++++++++++++++++++
 3 files changed, 25 insertions(+), 20 deletions(-)
 delete mode 100644 tests/run-make/issue-44282-questionmark-mangle/main.rs
 delete mode 100644 tests/run-make/issue-44282-questionmark-mangle/rmake.rs
 create mode 100644 tests/ui/symbol-names/symbol-with-question-mark-links.rs

diff --git a/tests/run-make/issue-44282-questionmark-mangle/main.rs b/tests/run-make/issue-44282-questionmark-mangle/main.rs
deleted file mode 100644
index d6df6b6133e17..0000000000000
--- a/tests/run-make/issue-44282-questionmark-mangle/main.rs
+++ /dev/null
@@ -1,11 +0,0 @@
-#![crate_type = "cdylib"]
-
-#[no_mangle]
-pub extern "C" fn foo(a: i32, b: i32) -> i32 {
-    1
-}
-
-#[export_name = "?bar@@YAXXZ"]
-pub extern "C" fn bar(a: i32, b: i32) -> i32 {
-    2
-}
diff --git a/tests/run-make/issue-44282-questionmark-mangle/rmake.rs b/tests/run-make/issue-44282-questionmark-mangle/rmake.rs
deleted file mode 100644
index 2fb91ef736f63..0000000000000
--- a/tests/run-make/issue-44282-questionmark-mangle/rmake.rs
+++ /dev/null
@@ -1,9 +0,0 @@
-// This test verifies that functions including a leading question mark
-// in their export_name attribute successfully compile.
-// This is only an issue on Windows 32-bit.
-
-use run_make_support::{run, run_fail, rustc};
-
-fn main() {
-    rustc().input("main.rs").target("i686-pc-windows-msvc").run();
-}
diff --git a/tests/ui/symbol-names/symbol-with-question-mark-links.rs b/tests/ui/symbol-names/symbol-with-question-mark-links.rs
new file mode 100644
index 0000000000000..5d46f0556555c
--- /dev/null
+++ b/tests/ui/symbol-names/symbol-with-question-mark-links.rs
@@ -0,0 +1,25 @@
+// This test ensures functions with an exported name beginning with a question mark
+// successfully compile and link.
+//
+// Regression test for <https://github.com/rust-lang/rust/issues/44282>
+
+//@ build-pass
+//@ only-windows
+//@ only-x86
+// Reason: This test regards a linker issue which only applies to Windows.
+// Specifically, it only occurs due to Windows x86 name decoration, combined with
+// a mismatch between LLVM's decoration logic and Rust's (for `lib.def` generation)
+
+#![crate_type = "cdylib"]
+
+#[no_mangle]
+pub extern "C" fn decorated(a: i32, b: i32) -> i32 {
+    1
+}
+
+// This isn't just `?undecorated` because MSVC's linker fails if the decorated
+// symbol is not valid.
+#[export_name = "?undecorated@@YAXXZ"]
+pub extern "C" fn undecorated(a: i32, b: i32) -> i32 {
+    2
+}

From f81ebfb485c143594ef69b2496917f6da4eb629e Mon Sep 17 00:00:00 2001
From: checkraisefold <checkraisefold@crf.gay>
Date: Mon, 13 Jan 2025 18:07:19 -0800
Subject: [PATCH 04/17] Match LLVM behavior more closely

Co-authored-by: David Wood <agile.lion3441@fuligin.ink>
---
 compiler/rustc_codegen_ssa/src/back/symbol_export.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/compiler/rustc_codegen_ssa/src/back/symbol_export.rs b/compiler/rustc_codegen_ssa/src/back/symbol_export.rs
index 25723dd1a5824..6dd4617e283e1 100644
--- a/compiler/rustc_codegen_ssa/src/back/symbol_export.rs
+++ b/compiler/rustc_codegen_ssa/src/back/symbol_export.rs
@@ -577,7 +577,7 @@ pub(crate) fn linking_symbol_name_for_instance_in_crate<'tcx>(
     }
 
     let prefix = match &target.arch[..] {
-        "x86" if target.is_like_windows && undecorated.starts_with("?") => return undecorated,
+        "x86" | "x86_64" if target.is_like_msvc && undecorated.starts_with("?") => return undecorated,
         "x86" => Some('_'),
         "x86_64" => None,
         "arm64ec" => Some('#'),

From bf3633870d4026ea9a39695a0d28b9cd6f20dea5 Mon Sep 17 00:00:00 2001
From: checkraisefold <checkraisefold@crf.gay>
Date: Tue, 14 Jan 2025 01:49:17 -0800
Subject: [PATCH 05/17] Accept tidy changes

---
 compiler/rustc_codegen_ssa/src/back/symbol_export.rs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/compiler/rustc_codegen_ssa/src/back/symbol_export.rs b/compiler/rustc_codegen_ssa/src/back/symbol_export.rs
index 6dd4617e283e1..043ba97eca907 100644
--- a/compiler/rustc_codegen_ssa/src/back/symbol_export.rs
+++ b/compiler/rustc_codegen_ssa/src/back/symbol_export.rs
@@ -577,7 +577,9 @@ pub(crate) fn linking_symbol_name_for_instance_in_crate<'tcx>(
     }
 
     let prefix = match &target.arch[..] {
-        "x86" | "x86_64" if target.is_like_msvc && undecorated.starts_with("?") => return undecorated,
+        "x86" | "x86_64" if target.is_like_msvc && undecorated.starts_with("?") => {
+            return undecorated
+        }
         "x86" => Some('_'),
         "x86_64" => None,
         "arm64ec" => Some('#'),

From 9c3b53daf581aa0088a39572db4e6e1508f29eb3 Mon Sep 17 00:00:00 2001
From: checkraisefold <checkraisefold@crf.gay>
Date: Tue, 14 Jan 2025 02:19:14 -0800
Subject: [PATCH 06/17] Apply tidy suggestion (2)

---
 compiler/rustc_codegen_ssa/src/back/symbol_export.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/compiler/rustc_codegen_ssa/src/back/symbol_export.rs b/compiler/rustc_codegen_ssa/src/back/symbol_export.rs
index 043ba97eca907..20881093f97b5 100644
--- a/compiler/rustc_codegen_ssa/src/back/symbol_export.rs
+++ b/compiler/rustc_codegen_ssa/src/back/symbol_export.rs
@@ -578,7 +578,7 @@ pub(crate) fn linking_symbol_name_for_instance_in_crate<'tcx>(
 
     let prefix = match &target.arch[..] {
         "x86" | "x86_64" if target.is_like_msvc && undecorated.starts_with("?") => {
-            return undecorated
+            return undecorated;
         }
         "x86" => Some('_'),
         "x86_64" => None,

From 893d81f1e219109d098309d9e3f435b9097da47f Mon Sep 17 00:00:00 2001
From: Folkert de Vries <folkert@folkertdev.nl>
Date: Mon, 20 Jan 2025 15:46:53 +0100
Subject: [PATCH 07/17] on s390x, use `PassMode::Direct` for vector types

---
 compiler/rustc_target/src/callconv/s390x.rs |  14 +-
 tests/codegen/s390x-simd.rs                 | 143 ++++++++++++++++++++
 2 files changed, 154 insertions(+), 3 deletions(-)
 create mode 100644 tests/codegen/s390x-simd.rs

diff --git a/compiler/rustc_target/src/callconv/s390x.rs b/compiler/rustc_target/src/callconv/s390x.rs
index c99eb9226eff1..a73c1a0f46c2b 100644
--- a/compiler/rustc_target/src/callconv/s390x.rs
+++ b/compiler/rustc_target/src/callconv/s390x.rs
@@ -38,9 +38,17 @@ where
     }
 
     let size = arg.layout.size;
-    if size.bits() <= 128 && arg.layout.is_single_vector_element(cx, size) {
-        arg.cast_to(Reg { kind: RegKind::Vector, size });
-        return;
+    if size.bits() <= 128 {
+        if let BackendRepr::Vector { .. } = arg.layout.backend_repr {
+            // pass non-wrapped vector types using `PassMode::Direct`
+            return;
+        }
+
+        if arg.layout.is_single_vector_element(cx, size) {
+            // pass non-transparant wrappers around a vector as `PassMode::Cast`
+            arg.cast_to(Reg { kind: RegKind::Vector, size });
+            return;
+        }
     }
     if !arg.layout.is_aggregate() && size.bits() <= 64 {
         arg.extend_integer_width_to(64);
diff --git a/tests/codegen/s390x-simd.rs b/tests/codegen/s390x-simd.rs
new file mode 100644
index 0000000000000..23181e6a10308
--- /dev/null
+++ b/tests/codegen/s390x-simd.rs
@@ -0,0 +1,143 @@
+//! test that s390x vector types are passed using `PassMode::Direct`
+//! see also https://github.com/rust-lang/rust/issues/135744
+//@ add-core-stubs
+//@ compile-flags: --target s390x-unknown-linux-gnu -O
+//@ needs-llvm-components: systemz
+
+#![crate_type = "rlib"]
+#![feature(no_core, asm_experimental_arch)]
+#![feature(s390x_target_feature, simd_ffi, link_llvm_intrinsics, repr_simd)]
+#![no_core]
+
+extern crate minicore;
+use minicore::*;
+
+#[repr(simd)]
+struct i8x16([i8; 16]);
+
+#[repr(simd)]
+struct i16x8([i16; 8]);
+
+#[repr(simd)]
+struct i32x4([i32; 4]);
+
+#[repr(simd)]
+struct i64x2([i64; 2]);
+
+#[repr(simd)]
+struct f32x4([f32; 4]);
+
+#[repr(simd)]
+struct f64x2([f64; 2]);
+
+#[allow(improper_ctypes)]
+extern "C" {
+    #[link_name = "llvm.smax.v16i8"]
+    fn vmxb(a: i8x16, b: i8x16) -> i8x16;
+    #[link_name = "llvm.smax.v8i16"]
+    fn vmxh(a: i16x8, b: i16x8) -> i16x8;
+    #[link_name = "llvm.smax.v4i32"]
+    fn vmxf(a: i32x4, b: i32x4) -> i32x4;
+    #[link_name = "llvm.smax.v2i64"]
+    fn vmxg(a: i64x2, b: i64x2) -> i64x2;
+}
+
+// CHECK-LABEL: define <16 x i8> @max_i8x16
+// CHECK-SAME: <16 x i8> %a, <16 x i8> %b
+// CHECK: call <16 x i8> @llvm.smax.v16i8(<16 x i8> %a, <16 x i8> %b)
+#[no_mangle]
+#[target_feature(enable = "vector")]
+pub unsafe extern "C" fn max_i8x16(a: i8x16, b: i8x16) -> i8x16 {
+    vmxb(a, b)
+}
+
+// CHECK-LABEL: define <8 x i16> @max_i16x8
+// CHECK-SAME: <8 x i16> %a, <8 x i16> %b
+// CHECK: call <8 x i16> @llvm.smax.v8i16(<8 x i16> %a, <8 x i16> %b)
+#[no_mangle]
+#[target_feature(enable = "vector")]
+pub unsafe extern "C" fn max_i16x8(a: i16x8, b: i16x8) -> i16x8 {
+    vmxh(a, b)
+}
+
+// CHECK-LABEL: define <4 x i32> @max_i32x4
+// CHECK-SAME: <4 x i32> %a, <4 x i32> %b
+// CHECK: call <4 x i32> @llvm.smax.v4i32(<4 x i32> %a, <4 x i32> %b)
+#[no_mangle]
+#[target_feature(enable = "vector")]
+pub unsafe extern "C" fn max_i32x4(a: i32x4, b: i32x4) -> i32x4 {
+    vmxf(a, b)
+}
+
+// CHECK-LABEL: define <2 x i64> @max_i64x2
+// CHECK-SAME: <2 x i64> %a, <2 x i64> %b
+// CHECK: call <2 x i64> @llvm.smax.v2i64(<2 x i64> %a, <2 x i64> %b)
+#[no_mangle]
+#[target_feature(enable = "vector")]
+pub unsafe extern "C" fn max_i64x2(a: i64x2, b: i64x2) -> i64x2 {
+    vmxg(a, b)
+}
+
+// CHECK-LABEL: define <4 x float> @choose_f32x4
+// CHECK-SAME: <4 x float> %a, <4 x float> %b
+#[no_mangle]
+#[target_feature(enable = "vector")]
+pub unsafe extern "C" fn choose_f32x4(a: f32x4, b: f32x4, c: bool) -> f32x4 {
+    if c { a } else { b }
+}
+
+// CHECK-LABEL: define <2 x double> @choose_f64x2
+// CHECK-SAME: <2 x double> %a, <2 x double> %b
+#[no_mangle]
+#[target_feature(enable = "vector")]
+pub unsafe extern "C" fn choose_f64x2(a: f64x2, b: f64x2, c: bool) -> f64x2 {
+    if c { a } else { b }
+}
+
+#[repr(C)]
+struct Wrapper<T>(T);
+
+#[no_mangle]
+#[inline(never)]
+#[target_feature(enable = "vector")]
+pub unsafe extern "C" fn max_wrapper_i8x16(a: Wrapper<i8x16>, b: Wrapper<i8x16>) -> Wrapper<i8x16> {
+    // CHECK-LABEL: max_wrapper_i8x16
+    // CHECK-SAME: sret([16 x i8])
+    // CHECK-SAME: <16 x i8>
+    // CHECK-SAME: <16 x i8>
+    // CHECK: call <16 x i8> @llvm.smax.v16i8
+    // CHECK-SAME: <16 x i8>
+    // CHECK-SAME: <16 x i8>
+    Wrapper(vmxb(a.0, b.0))
+}
+
+#[no_mangle]
+#[inline(never)]
+#[target_feature(enable = "vector")]
+pub unsafe extern "C" fn max_wrapper_i64x2(a: Wrapper<i64x2>, b: Wrapper<i64x2>) -> Wrapper<i64x2> {
+    // CHECK-LABEL: max_wrapper_i64x2
+    // CHECK-SAME: sret([16 x i8])
+    // CHECK-SAME: <16 x i8>
+    // CHECK-SAME: <16 x i8>
+    // CHECK: call <2 x i64> @llvm.smax.v2i64
+    // CHECK-SAME: <2 x i64>
+    // CHECK-SAME: <2 x i64>
+    Wrapper(vmxg(a.0, b.0))
+}
+
+#[no_mangle]
+#[inline(never)]
+#[target_feature(enable = "vector")]
+pub unsafe extern "C" fn choose_wrapper_f64x2(
+    a: Wrapper<f64x2>,
+    b: Wrapper<f64x2>,
+    c: bool,
+) -> Wrapper<f64x2> {
+    // CHECK-LABEL: choose_wrapper_f64x2
+    // CHECK-SAME: sret([16 x i8])
+    // CHECK-SAME: <16 x i8>
+    // CHECK-SAME: <16 x i8>
+    Wrapper(choose_f64x2(a.0, b.0, c))
+}
+
+// CHECK: declare <2 x i64> @llvm.smax.v2i64(<2 x i64>, <2 x i64>)

From 9d6a1c980e7de879d6eb64c281aac3cdfdefce3f Mon Sep 17 00:00:00 2001
From: jyn <github@jyn.dev>
Date: Sat, 18 Jan 2025 16:55:31 -0500
Subject: [PATCH 08/17] Shorten linker output even more when `--verbose` is not
 present

- Don't show environment variables. Seeing PATH is almost never useful, and it can be extremely long.
- For .rlibs in the sysroot, replace crate hashes with a `"-*"` string. This will expand to the full crate name when pasted into the shell.
- Move `.rlib` to outside the glob.
- Abbreviate the sysroot path to `<sysroot>` wherever it appears in the arguments.

This also adds an example of the linker output as a run-make test. Currently it only runs on x86_64-unknown-linux-gnu, because each platform has its own linker arguments. So that it's stable across machines, pass BUILD_ROOT as an argument through compiletest through to run-make tests.
---
 Cargo.lock                                    |  1 +
 compiler/rustc_codegen_ssa/Cargo.toml         |  1 +
 .../rustc_codegen_ssa/src/back/command.rs     | 17 ++++-
 compiler/rustc_codegen_ssa/src/back/link.rs   |  1 +
 compiler/rustc_codegen_ssa/src/errors.rs      | 62 ++++++++++++++-----
 src/tools/compiletest/src/runtest/run_make.rs |  2 +
 src/tools/run-make-support/src/lib.rs         |  2 +-
 .../run-make-support/src/path_helpers.rs      |  6 ++
 src/tools/tidy/src/deps.rs                    |  1 +
 tests/run-make/linker-warning/rmake.rs        | 41 ++++++++----
 tests/run-make/linker-warning/short-error.txt |  9 +++
 11 files changed, 115 insertions(+), 28 deletions(-)
 create mode 100644 tests/run-make/linker-warning/short-error.txt

diff --git a/Cargo.lock b/Cargo.lock
index a08d43a014c06..2917b9ef5d91a 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3536,6 +3536,7 @@ dependencies = [
  "ar_archive_writer",
  "arrayvec",
  "bitflags",
+ "bstr",
  "cc",
  "either",
  "itertools",
diff --git a/compiler/rustc_codegen_ssa/Cargo.toml b/compiler/rustc_codegen_ssa/Cargo.toml
index 3254b5d38e7a4..904297b987268 100644
--- a/compiler/rustc_codegen_ssa/Cargo.toml
+++ b/compiler/rustc_codegen_ssa/Cargo.toml
@@ -8,6 +8,7 @@ edition = "2021"
 ar_archive_writer = "0.4.2"
 arrayvec = { version = "0.7", default-features = false }
 bitflags = "2.4.1"
+bstr = "1.11.3"
 # Pinned so `cargo update` bumps don't cause breakage. Please also update the
 # `cc` in `rustc_llvm` if you update the `cc` here.
 cc = "=1.2.7"
diff --git a/compiler/rustc_codegen_ssa/src/back/command.rs b/compiler/rustc_codegen_ssa/src/back/command.rs
index b3c5b86ccf430..63023fdba20fc 100644
--- a/compiler/rustc_codegen_ssa/src/back/command.rs
+++ b/compiler/rustc_codegen_ssa/src/back/command.rs
@@ -13,6 +13,7 @@ pub(crate) struct Command {
     args: Vec<OsString>,
     env: Vec<(OsString, OsString)>,
     env_remove: Vec<OsString>,
+    env_clear: bool,
 }
 
 #[derive(Clone)]
@@ -36,7 +37,13 @@ impl Command {
     }
 
     fn _new(program: Program) -> Command {
-        Command { program, args: Vec::new(), env: Vec::new(), env_remove: Vec::new() }
+        Command {
+            program,
+            args: Vec::new(),
+            env: Vec::new(),
+            env_remove: Vec::new(),
+            env_clear: false,
+        }
     }
 
     pub(crate) fn arg<P: AsRef<OsStr>>(&mut self, arg: P) -> &mut Command {
@@ -79,6 +86,11 @@ impl Command {
         self
     }
 
+    pub(crate) fn env_clear(&mut self) -> &mut Command {
+        self.env_clear = true;
+        self
+    }
+
     fn _env_remove(&mut self, key: &OsStr) {
         self.env_remove.push(key.to_owned());
     }
@@ -106,6 +118,9 @@ impl Command {
         for k in &self.env_remove {
             ret.env_remove(k);
         }
+        if self.env_clear {
+            ret.env_clear();
+        }
         ret
     }
 
diff --git a/compiler/rustc_codegen_ssa/src/back/link.rs b/compiler/rustc_codegen_ssa/src/back/link.rs
index df35b5e8426f1..ba59bd1266af7 100644
--- a/compiler/rustc_codegen_ssa/src/back/link.rs
+++ b/compiler/rustc_codegen_ssa/src/back/link.rs
@@ -991,6 +991,7 @@ fn link_natively(
                     command: cmd,
                     escaped_output,
                     verbose: sess.opts.verbose,
+                    sysroot_dir: sess.sysroot.clone(),
                 };
                 sess.dcx().emit_err(err);
                 // If MSVC's `link.exe` was expected but the return code
diff --git a/compiler/rustc_codegen_ssa/src/errors.rs b/compiler/rustc_codegen_ssa/src/errors.rs
index c7213bbc801f9..5e684632fb247 100644
--- a/compiler/rustc_codegen_ssa/src/errors.rs
+++ b/compiler/rustc_codegen_ssa/src/errors.rs
@@ -351,6 +351,7 @@ pub(crate) struct LinkingFailed<'a> {
     pub command: Command,
     pub escaped_output: String,
     pub verbose: bool,
+    pub sysroot_dir: PathBuf,
 }
 
 impl<G: EmissionGuarantee> Diagnostic<'_, G> for LinkingFailed<'_> {
@@ -364,6 +365,8 @@ impl<G: EmissionGuarantee> Diagnostic<'_, G> for LinkingFailed<'_> {
         if self.verbose {
             diag.note(format!("{:?}", self.command));
         } else {
+            self.command.env_clear();
+
             enum ArgGroup {
                 Regular(OsString),
                 Objects(usize),
@@ -398,26 +401,55 @@ impl<G: EmissionGuarantee> Diagnostic<'_, G> for LinkingFailed<'_> {
                     args.push(ArgGroup::Regular(arg));
                 }
             }
-            self.command.args(args.into_iter().map(|arg_group| match arg_group {
-                ArgGroup::Regular(arg) => arg,
-                ArgGroup::Objects(n) => OsString::from(format!("<{n} object files omitted>")),
-                ArgGroup::Rlibs(dir, rlibs) => {
-                    let mut arg = dir.into_os_string();
-                    arg.push("/{");
-                    let mut first = true;
-                    for rlib in rlibs {
-                        if !first {
-                            arg.push(",");
+            let crate_hash = regex::bytes::Regex::new(r"-[0-9a-f]+\.rlib$").unwrap();
+            self.command.args(args.into_iter().map(|arg_group| {
+                match arg_group {
+                    // SAFETY: we are only matching on ASCII, not any surrogate pairs, so any replacements we do will still be valid.
+                    ArgGroup::Regular(arg) => unsafe {
+                        use bstr::ByteSlice;
+                        OsString::from_encoded_bytes_unchecked(
+                            arg.as_encoded_bytes().replace(
+                                self.sysroot_dir.as_os_str().as_encoded_bytes(),
+                                b"<sysroot>",
+                            ),
+                        )
+                    },
+                    ArgGroup::Objects(n) => OsString::from(format!("<{n} object files omitted>")),
+                    ArgGroup::Rlibs(mut dir, rlibs) => {
+                        let is_sysroot_dir = match dir.strip_prefix(&self.sysroot_dir) {
+                            Ok(short) => {
+                                dir = Path::new("<sysroot>").join(short);
+                                true
+                            }
+                            Err(_) => false,
+                        };
+                        let mut arg = dir.into_os_string();
+                        arg.push("/{");
+                        let mut first = true;
+                        for mut rlib in rlibs {
+                            if !first {
+                                arg.push(",");
+                            }
+                            first = false;
+                            if is_sysroot_dir {
+                                // SAFETY: Regex works one byte at a type, and our regex will not match surrogate pairs (because it only matches ascii).
+                                rlib = unsafe {
+                                    OsString::from_encoded_bytes_unchecked(
+                                        crate_hash
+                                            .replace(rlib.as_encoded_bytes(), b"-*")
+                                            .into_owned(),
+                                    )
+                                };
+                            }
+                            arg.push(rlib);
                         }
-                        first = false;
-                        arg.push(rlib);
+                        arg.push("}.rlib");
+                        arg
                     }
-                    arg.push("}");
-                    arg
                 }
             }));
 
-            diag.note(format!("{:?}", self.command));
+            diag.note(format!("{:?}", self.command).trim_start_matches("env -i").to_owned());
             diag.note("some arguments are omitted. use `--verbose` to show all linker arguments");
         }
 
diff --git a/src/tools/compiletest/src/runtest/run_make.rs b/src/tools/compiletest/src/runtest/run_make.rs
index 8a49d63053521..7ef16e4a9667b 100644
--- a/src/tools/compiletest/src/runtest/run_make.rs
+++ b/src/tools/compiletest/src/runtest/run_make.rs
@@ -414,6 +414,8 @@ impl TestCx<'_> {
             // Provide path to checkout root. This is the top-level directory containing
             // rust-lang/rust checkout.
             .env("SOURCE_ROOT", &source_root)
+            // Path to the build directory. This is usually the same as `source_root.join("build").join("host")`.
+            .env("BUILD_ROOT", &build_root)
             // Provide path to stage-corresponding rustc.
             .env("RUSTC", &self.config.rustc_path)
             // Provide the directory to libraries that are needed to run the *compiler*. This is not
diff --git a/src/tools/run-make-support/src/lib.rs b/src/tools/run-make-support/src/lib.rs
index ffd4ca22a0086..7316244b3841d 100644
--- a/src/tools/run-make-support/src/lib.rs
+++ b/src/tools/run-make-support/src/lib.rs
@@ -90,7 +90,7 @@ pub use artifact_names::{
 /// Path-related helpers.
 pub use path_helpers::{
     cwd, filename_contains, filename_not_in_denylist, has_extension, has_prefix, has_suffix,
-    not_contains, path, shallow_find_files, source_root,
+    not_contains, path, shallow_find_files, build_root, source_root,
 };
 
 /// Helpers for scoped test execution where certain properties are attempted to be maintained.
diff --git a/src/tools/run-make-support/src/path_helpers.rs b/src/tools/run-make-support/src/path_helpers.rs
index 87901793a921e..1c59f2feea4c7 100644
--- a/src/tools/run-make-support/src/path_helpers.rs
+++ b/src/tools/run-make-support/src/path_helpers.rs
@@ -34,6 +34,12 @@ pub fn source_root() -> PathBuf {
     env_var("SOURCE_ROOT").into()
 }
 
+/// Path to the build directory root.
+#[must_use]
+pub fn build_root() -> PathBuf {
+    env_var("BUILD_ROOT").into()
+}
+
 /// Browse the directory `path` non-recursively and return all files which respect the parameters
 /// outlined by `closure`.
 #[track_caller]
diff --git a/src/tools/tidy/src/deps.rs b/src/tools/tidy/src/deps.rs
index d4cbc37f6d2b3..e9e2deb240f5f 100644
--- a/src/tools/tidy/src/deps.rs
+++ b/src/tools/tidy/src/deps.rs
@@ -253,6 +253,7 @@ const PERMITTED_RUSTC_DEPENDENCIES: &[&str] = &[
     "bitflags",
     "blake3",
     "block-buffer",
+    "bstr",
     "byteorder", // via ruzstd in object in thorin-dwp
     "cc",
     "cfg-if",
diff --git a/tests/run-make/linker-warning/rmake.rs b/tests/run-make/linker-warning/rmake.rs
index 4d21c5ea5690a..88e467e6cce3f 100644
--- a/tests/run-make/linker-warning/rmake.rs
+++ b/tests/run-make/linker-warning/rmake.rs
@@ -1,8 +1,16 @@
-use run_make_support::{Rustc, rustc};
+use run_make_support::{Rustc, diff, regex, rustc};
 
 fn run_rustc() -> Rustc {
     let mut rustc = rustc();
-    rustc.arg("main.rs").output("main").linker("./fake-linker");
+    rustc
+        .arg("main.rs")
+        // NOTE: `link-self-contained` can vary depending on config.toml.
+        // Make sure we use a consistent value.
+        .arg("-Clink-self-contained=-linker")
+        .arg("-Clinker-flavor=gnu-cc")
+        .arg("-Zunstable-options")
+        .output("main")
+        .linker("./fake-linker");
     rustc
 }
 
@@ -11,18 +19,29 @@ fn main() {
     rustc().arg("fake-linker.rs").output("fake-linker").run();
 
     // Make sure we don't show the linker args unless `--verbose` is passed
-    run_rustc()
-        .link_arg("run_make_error")
-        .verbose()
-        .run_fail()
-        .assert_stderr_contains_regex("fake-linker.*run_make_error")
+    let out = run_rustc().link_arg("run_make_error").verbose().run_fail();
+    out.assert_stderr_contains_regex("fake-linker.*run_make_error")
         .assert_stderr_not_contains("object files omitted")
+        .assert_stderr_contains("PATH=\"")
         .assert_stderr_contains_regex(r"lib(/|\\\\)libstd");
-    run_rustc()
-        .link_arg("run_make_error")
-        .run_fail()
-        .assert_stderr_contains("fake-linker")
+
+    let out = run_rustc().link_arg("run_make_error").run_fail();
+    out.assert_stderr_contains("fake-linker")
         .assert_stderr_contains("object files omitted")
         .assert_stderr_contains_regex(r"\{")
+        .assert_stderr_not_contains("PATH=\"")
         .assert_stderr_not_contains_regex(r"lib(/|\\\\)libstd");
+
+    // FIXME: we should have a version of this for mac and windows
+    if run_make_support::target() == "x86_64-unknown-linux-gnu" {
+        diff()
+            .expected_file("short-error.txt")
+            .actual_text("(linker error)", out.stderr())
+            .normalize(r#"/rustc[^/]*/"#, "/rustc/")
+            .normalize(
+                regex::escape(run_make_support::build_root().to_str().unwrap()),
+                "/build-root",
+            )
+            .run();
+    }
 }
diff --git a/tests/run-make/linker-warning/short-error.txt b/tests/run-make/linker-warning/short-error.txt
new file mode 100644
index 0000000000000..dd3b742bbfd56
--- /dev/null
+++ b/tests/run-make/linker-warning/short-error.txt
@@ -0,0 +1,9 @@
+error: linking with `./fake-linker` failed: exit status: 1
+  |
+  = note:  "./fake-linker" "-m64" "/tmp/rustc/symbols.o" "<2 object files omitted>" "-Wl,--as-needed" "-Wl,-Bstatic" "<sysroot>/lib/rustlib/x86_64-unknown-linux-gnu/lib/{libstd-*,libpanic_unwind-*,libobject-*,libmemchr-*,libaddr2line-*,libgimli-*,librustc_demangle-*,libstd_detect-*,libhashbrown-*,librustc_std_workspace_alloc-*,libminiz_oxide-*,libadler2-*,libunwind-*,libcfg_if-*,liblibc-*,liballoc-*,librustc_std_workspace_core-*,libcore-*,libcompiler_builtins-*}.rlib" "-Wl,-Bdynamic" "-lgcc_s" "-lutil" "-lrt" "-lpthread" "-lm" "-ldl" "-lc" "-Wl,--eh-frame-hdr" "-Wl,-z,noexecstack" "-L" "/build-root/test/run-make/linker-warning/rmake_out" "-L" "<sysroot>/lib/rustlib/x86_64-unknown-linux-gnu/lib" "-o" "main" "-Wl,--gc-sections" "-pie" "-Wl,-z,relro,-z,now" "-nodefaultlibs" "run_make_error"
+  = note: some arguments are omitted. use `--verbose` to show all linker arguments
+  = note: error: baz
+          
+
+error: aborting due to 1 previous error
+

From 2a544ab4ad62dc2756a27a2a3f2e9eed3072b4c9 Mon Sep 17 00:00:00 2001
From: Andrew Zhogin <andrew.zhogin@gmail.com>
Date: Mon, 18 Nov 2024 04:07:29 +0700
Subject: [PATCH 09/17] Target modifiers (special marked options) are recorded
 in metainfo and compared to be equal in different crates

---
 compiler/rustc_interface/src/passes.rs        |   1 +
 compiler/rustc_metadata/messages.ftl          |  10 +
 compiler/rustc_metadata/src/creader.rs        | 120 ++++++-
 compiler/rustc_metadata/src/errors.rs         |  25 ++
 compiler/rustc_metadata/src/rmeta/decoder.rs  |  19 +
 compiler/rustc_metadata/src/rmeta/encoder.rs  |  10 +-
 compiler/rustc_metadata/src/rmeta/mod.rs      |   5 +-
 compiler/rustc_middle/src/ty/parameterized.rs |   1 +
 compiler/rustc_session/src/config.rs          |   8 +-
 compiler/rustc_session/src/lib.rs             |   3 +
 compiler/rustc_session/src/options.rs         | 337 +++++++++++++++++-
 src/librustdoc/config.rs                      |   9 +-
 .../auxiliary/default_reg_struct_return.rs    |  14 +
 .../auxiliary/wrong_regparm.rs                |  14 +
 .../auxiliary/wrong_regparm_and_ret.rs        |  14 +
 .../defaults_check.error.stderr               |  13 +
 tests/ui/target_modifiers/defaults_check.rs   |  20 ++
 ...incompatible_regparm.allow_no_value.stderr |   2 +
 ...ncompatible_regparm.error_generated.stderr |  13 +
 .../target_modifiers/incompatible_regparm.rs  |  17 +
 tests/ui/target_modifiers/two_flags.rs        |  17 +
 .../two_flags.unknown_allowed.stderr          |   8 +
 22 files changed, 656 insertions(+), 24 deletions(-)
 create mode 100644 tests/ui/target_modifiers/auxiliary/default_reg_struct_return.rs
 create mode 100644 tests/ui/target_modifiers/auxiliary/wrong_regparm.rs
 create mode 100644 tests/ui/target_modifiers/auxiliary/wrong_regparm_and_ret.rs
 create mode 100644 tests/ui/target_modifiers/defaults_check.error.stderr
 create mode 100644 tests/ui/target_modifiers/defaults_check.rs
 create mode 100644 tests/ui/target_modifiers/incompatible_regparm.allow_no_value.stderr
 create mode 100644 tests/ui/target_modifiers/incompatible_regparm.error_generated.stderr
 create mode 100644 tests/ui/target_modifiers/incompatible_regparm.rs
 create mode 100644 tests/ui/target_modifiers/two_flags.rs
 create mode 100644 tests/ui/target_modifiers/two_flags.unknown_allowed.stderr

diff --git a/compiler/rustc_interface/src/passes.rs b/compiler/rustc_interface/src/passes.rs
index aff66e48fbbee..df41a96ffacbf 100644
--- a/compiler/rustc_interface/src/passes.rs
+++ b/compiler/rustc_interface/src/passes.rs
@@ -269,6 +269,7 @@ fn configure_and_expand(
 
     resolver.resolve_crate(&krate);
 
+    CStore::from_tcx(tcx).report_incompatible_target_modifiers(tcx, &krate);
     krate
 }
 
diff --git a/compiler/rustc_metadata/messages.ftl b/compiler/rustc_metadata/messages.ftl
index 6d7d88fa8d7af..4d5dda210ad5f 100644
--- a/compiler/rustc_metadata/messages.ftl
+++ b/compiler/rustc_metadata/messages.ftl
@@ -113,6 +113,14 @@ metadata_incompatible_rustc =
     found crate `{$crate_name}` compiled by an incompatible version of rustc{$add_info}
     .help = please recompile that crate using this compiler ({$rustc_version}) (consider running `cargo clean` first)
 
+metadata_incompatible_target_modifiers =
+    mixing `{$flag_name_prefixed}` will cause an ABI mismatch in crate `{$local_crate}`
+    .note = `{$flag_name_prefixed}={$flag_local_value}` in this crate is incompatible with `{$flag_name_prefixed}={$flag_extern_value}` in dependency `{$extern_crate}`
+    .help = the `{$flag_name_prefixed}` flag modifies the ABI so Rust crates compiled with different values of this flag cannot be used together safely
+
+metadata_incompatible_target_modifiers_help_allow = if you are sure this will not cause problems, you may use `-Cunsafe-allow-abi-mismatch={$flag_name}` to silence this error
+metadata_incompatible_target_modifiers_help_fix = set `{$flag_name_prefixed}={$flag_extern_value}` in this crate or `{$flag_name_prefixed}={$flag_local_value}` in `{$extern_crate}`
+
 metadata_incompatible_wasm_link =
     `wasm_import_module` is incompatible with other arguments in `#[link]` attributes
 
@@ -284,6 +292,8 @@ metadata_unknown_link_kind =
 metadata_unknown_link_modifier =
     unknown linking modifier `{$modifier}`, expected one of: bundle, verbatim, whole-archive, as-needed
 
+metadata_unknown_target_modifier_unsafe_allowed = unknown target modifier `{$flag_name}`, requested by `-Cunsafe-allow-abi-mismatch={$flag_name}`
+
 metadata_unsupported_abi =
     ABI not supported by `#[link(kind = "raw-dylib")]` on this architecture
 
diff --git a/compiler/rustc_metadata/src/creader.rs b/compiler/rustc_metadata/src/creader.rs
index 6512176cc4a90..73c155560a5da 100644
--- a/compiler/rustc_metadata/src/creader.rs
+++ b/compiler/rustc_metadata/src/creader.rs
@@ -23,7 +23,10 @@ use rustc_hir::definitions::Definitions;
 use rustc_index::IndexVec;
 use rustc_middle::bug;
 use rustc_middle::ty::{TyCtxt, TyCtxtFeed};
-use rustc_session::config::{self, CrateType, ExternLocation};
+use rustc_session::config::{
+    self, CrateType, ExtendedTargetModifierInfo, ExternLocation, OptionsTargetModifiers,
+    TargetModifier,
+};
 use rustc_session::cstore::{CrateDepKind, CrateSource, ExternCrate, ExternCrateSource};
 use rustc_session::lint::{self, BuiltinLintDiag};
 use rustc_session::output::validate_crate_name;
@@ -35,7 +38,9 @@ use tracing::{debug, info, trace};
 
 use crate::errors;
 use crate::locator::{CrateError, CrateLocator, CratePaths};
-use crate::rmeta::{CrateDep, CrateMetadata, CrateNumMap, CrateRoot, MetadataBlob};
+use crate::rmeta::{
+    CrateDep, CrateMetadata, CrateNumMap, CrateRoot, MetadataBlob, TargetModifiers,
+};
 
 /// The backend's way to give the crate store access to the metadata in a library.
 /// Note that it returns the raw metadata bytes stored in the library file, whether
@@ -296,6 +301,96 @@ impl CStore {
         }
     }
 
+    fn report_target_modifiers_extended(
+        tcx: TyCtxt<'_>,
+        krate: &Crate,
+        mods: &Vec<TargetModifier>,
+        data: &CrateMetadata,
+    ) {
+        let span = krate.spans.inner_span.shrink_to_lo();
+        let allowed_flag_mismatches = &tcx.sess.opts.cg.unsafe_allow_abi_mismatch;
+        let name = tcx.crate_name(LOCAL_CRATE);
+        let tmod_extender = |tmod: &TargetModifier| (tmod.extend(), tmod.clone());
+        let report_diff = |prefix: &String,
+                           opt_name: &String,
+                           flag_local_value: &String,
+                           flag_extern_value: &String| {
+            if allowed_flag_mismatches.contains(&opt_name) {
+                return;
+            }
+            tcx.dcx().emit_err(errors::IncompatibleTargetModifiers {
+                span,
+                extern_crate: data.name(),
+                local_crate: name,
+                flag_name: opt_name.clone(),
+                flag_name_prefixed: format!("-{}{}", prefix, opt_name),
+                flag_local_value: flag_local_value.to_string(),
+                flag_extern_value: flag_extern_value.to_string(),
+            });
+        };
+        let mut it1 = mods.iter().map(tmod_extender);
+        let mut it2 = data.target_modifiers().iter().map(tmod_extender);
+        let mut left_name_val: Option<(ExtendedTargetModifierInfo, TargetModifier)> = None;
+        let mut right_name_val: Option<(ExtendedTargetModifierInfo, TargetModifier)> = None;
+        let no_val = "*".to_string();
+        loop {
+            left_name_val = left_name_val.or_else(|| it1.next());
+            right_name_val = right_name_val.or_else(|| it2.next());
+            match (&left_name_val, &right_name_val) {
+                (Some(l), Some(r)) => match l.1.opt.cmp(&r.1.opt) {
+                    cmp::Ordering::Equal => {
+                        if l.0.tech_value != r.0.tech_value {
+                            report_diff(&l.0.prefix, &l.0.name, &l.1.value_name, &r.1.value_name);
+                        }
+                        left_name_val = None;
+                        right_name_val = None;
+                    }
+                    cmp::Ordering::Greater => {
+                        report_diff(&r.0.prefix, &r.0.name, &no_val, &r.1.value_name);
+                        right_name_val = None;
+                    }
+                    cmp::Ordering::Less => {
+                        report_diff(&l.0.prefix, &l.0.name, &l.1.value_name, &no_val);
+                        left_name_val = None;
+                    }
+                },
+                (Some(l), None) => {
+                    report_diff(&l.0.prefix, &l.0.name, &l.1.value_name, &no_val);
+                    left_name_val = None;
+                }
+                (None, Some(r)) => {
+                    report_diff(&r.0.prefix, &r.0.name, &no_val, &r.1.value_name);
+                    right_name_val = None;
+                }
+                (None, None) => break,
+            }
+        }
+    }
+
+    pub fn report_incompatible_target_modifiers(&self, tcx: TyCtxt<'_>, krate: &Crate) {
+        for flag_name in &tcx.sess.opts.cg.unsafe_allow_abi_mismatch {
+            if !OptionsTargetModifiers::is_target_modifier(flag_name) {
+                tcx.dcx().emit_err(errors::UnknownTargetModifierUnsafeAllowed {
+                    span: krate.spans.inner_span.shrink_to_lo(),
+                    flag_name: flag_name.clone(),
+                });
+            }
+        }
+
+        if tcx.crate_types().contains(&CrateType::ProcMacro) {
+            return;
+        }
+        let mods = tcx.sess.opts.gather_target_modifiers();
+        for (_cnum, data) in self.iter_crate_data() {
+            if data.is_proc_macro_crate() {
+                continue;
+            }
+            if mods != *data.target_modifiers() {
+                Self::report_target_modifiers_extended(tcx, krate, &mods, data);
+            }
+        }
+    }
+
     pub fn new(metadata_loader: Box<MetadataLoaderDyn>) -> CStore {
         CStore {
             metadata_loader,
@@ -470,6 +565,7 @@ impl<'a, 'tcx> CrateLoader<'a, 'tcx> {
         };
 
         let cnum_map = self.resolve_crate_deps(dep_root, &crate_root, &metadata, cnum, dep_kind)?;
+        let target_modifiers = self.resolve_target_modifiers(&crate_root, &metadata, cnum)?;
 
         let raw_proc_macros = if crate_root.is_proc_macro_crate() {
             let temp_root;
@@ -494,6 +590,7 @@ impl<'a, 'tcx> CrateLoader<'a, 'tcx> {
             raw_proc_macros,
             cnum,
             cnum_map,
+            target_modifiers,
             dep_kind,
             source,
             private_dep,
@@ -737,6 +834,25 @@ impl<'a, 'tcx> CrateLoader<'a, 'tcx> {
         Ok(crate_num_map)
     }
 
+    fn resolve_target_modifiers(
+        &mut self,
+        crate_root: &CrateRoot,
+        metadata: &MetadataBlob,
+        krate: CrateNum,
+    ) -> Result<TargetModifiers, CrateError> {
+        debug!("resolving target modifiers of external crate");
+        if crate_root.is_proc_macro_crate() {
+            return Ok(TargetModifiers::new());
+        }
+        let mods = crate_root.decode_target_modifiers(metadata);
+        let mut target_modifiers = TargetModifiers::with_capacity(mods.len());
+        for modifier in mods {
+            target_modifiers.push(modifier);
+        }
+        debug!("resolve_target_modifiers: target mods for {:?} is {:?}", krate, target_modifiers);
+        Ok(target_modifiers)
+    }
+
     fn dlsym_proc_macros(
         &self,
         path: &Path,
diff --git a/compiler/rustc_metadata/src/errors.rs b/compiler/rustc_metadata/src/errors.rs
index b6c5619ec18ae..eaac9e15c5a4b 100644
--- a/compiler/rustc_metadata/src/errors.rs
+++ b/compiler/rustc_metadata/src/errors.rs
@@ -732,3 +732,28 @@ pub struct ImportNameTypeRaw {
     #[primary_span]
     pub span: Span,
 }
+
+#[derive(Diagnostic)]
+#[diag(metadata_incompatible_target_modifiers)]
+#[help]
+#[note]
+#[help(metadata_incompatible_target_modifiers_help_fix)]
+#[help(metadata_incompatible_target_modifiers_help_allow)]
+pub struct IncompatibleTargetModifiers {
+    #[primary_span]
+    pub span: Span,
+    pub extern_crate: Symbol,
+    pub local_crate: Symbol,
+    pub flag_name: String,
+    pub flag_name_prefixed: String,
+    pub flag_local_value: String,
+    pub flag_extern_value: String,
+}
+
+#[derive(Diagnostic)]
+#[diag(metadata_unknown_target_modifier_unsafe_allowed)]
+pub struct UnknownTargetModifierUnsafeAllowed {
+    #[primary_span]
+    pub span: Span,
+    pub flag_name: String,
+}
diff --git a/compiler/rustc_metadata/src/rmeta/decoder.rs b/compiler/rustc_metadata/src/rmeta/decoder.rs
index e02c4871f35bd..4d0985b900a79 100644
--- a/compiler/rustc_metadata/src/rmeta/decoder.rs
+++ b/compiler/rustc_metadata/src/rmeta/decoder.rs
@@ -29,6 +29,7 @@ use rustc_middle::{bug, implement_ty_decoder};
 use rustc_serialize::opaque::MemDecoder;
 use rustc_serialize::{Decodable, Decoder};
 use rustc_session::Session;
+use rustc_session::config::TargetModifier;
 use rustc_session::cstore::{CrateSource, ExternCrate};
 use rustc_span::hygiene::HygieneDecodeContext;
 use rustc_span::{BytePos, DUMMY_SP, Pos, SpanData, SpanDecoder, SyntaxContext, kw};
@@ -73,6 +74,9 @@ impl MetadataBlob {
 /// own crate numbers.
 pub(crate) type CrateNumMap = IndexVec<CrateNum, CrateNum>;
 
+/// Target modifiers - abi or exploit mitigations flags
+pub(crate) type TargetModifiers = Vec<TargetModifier>;
+
 pub(crate) struct CrateMetadata {
     /// The primary crate data - binary metadata blob.
     blob: MetadataBlob,
@@ -110,6 +114,8 @@ pub(crate) struct CrateMetadata {
     cnum_map: CrateNumMap,
     /// Same ID set as `cnum_map` plus maybe some injected crates like panic runtime.
     dependencies: Vec<CrateNum>,
+    /// Target modifiers - abi and exploit mitigation flags the crate was compiled with
+    target_modifiers: TargetModifiers,
     /// How to link (or not link) this crate to the currently compiled crate.
     dep_kind: CrateDepKind,
     /// Filesystem location of this crate.
@@ -961,6 +967,13 @@ impl CrateRoot {
     ) -> impl ExactSizeIterator<Item = CrateDep> + Captures<'a> {
         self.crate_deps.decode(metadata)
     }
+
+    pub(crate) fn decode_target_modifiers<'a>(
+        &self,
+        metadata: &'a MetadataBlob,
+    ) -> impl ExactSizeIterator<Item = TargetModifier> + Captures<'a> {
+        self.target_modifiers.decode(metadata)
+    }
 }
 
 impl<'a> CrateMetadataRef<'a> {
@@ -1823,6 +1836,7 @@ impl CrateMetadata {
         raw_proc_macros: Option<&'static [ProcMacro]>,
         cnum: CrateNum,
         cnum_map: CrateNumMap,
+        target_modifiers: TargetModifiers,
         dep_kind: CrateDepKind,
         source: CrateSource,
         private_dep: bool,
@@ -1854,6 +1868,7 @@ impl CrateMetadata {
             cnum,
             cnum_map,
             dependencies,
+            target_modifiers,
             dep_kind,
             source: Lrc::new(source),
             private_dep,
@@ -1883,6 +1898,10 @@ impl CrateMetadata {
         self.dependencies.push(cnum);
     }
 
+    pub(crate) fn target_modifiers(&self) -> &TargetModifiers {
+        &self.target_modifiers
+    }
+
     pub(crate) fn update_extern_crate(&mut self, new_extern_crate: ExternCrate) -> bool {
         let update =
             Some(new_extern_crate.rank()) > self.extern_crate.as_ref().map(ExternCrate::rank);
diff --git a/compiler/rustc_metadata/src/rmeta/encoder.rs b/compiler/rustc_metadata/src/rmeta/encoder.rs
index c538ab99fb54b..161388a290b0f 100644
--- a/compiler/rustc_metadata/src/rmeta/encoder.rs
+++ b/compiler/rustc_metadata/src/rmeta/encoder.rs
@@ -25,7 +25,7 @@ use rustc_middle::ty::{AssocItemContainer, SymbolName};
 use rustc_middle::util::common::to_readable_str;
 use rustc_middle::{bug, span_bug};
 use rustc_serialize::{Decodable, Decoder, Encodable, Encoder, opaque};
-use rustc_session::config::{CrateType, OptLevel};
+use rustc_session::config::{CrateType, OptLevel, TargetModifier};
 use rustc_span::hygiene::HygieneEncodeContext;
 use rustc_span::{
     ExternalSource, FileName, SourceFile, SpanData, SpanEncoder, StableSourceFileId, SyntaxContext,
@@ -692,6 +692,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
         // Encode source_map. This needs to be done last, because encoding `Span`s tells us which
         // `SourceFiles` we actually need to encode.
         let source_map = stat!("source-map", || self.encode_source_map());
+        let target_modifiers = stat!("target-modifiers", || self.encode_target_modifiers());
 
         let root = stat!("final", || {
             let attrs = tcx.hir().krate_attrs();
@@ -735,6 +736,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
                 native_libraries,
                 foreign_modules,
                 source_map,
+                target_modifiers,
                 traits,
                 impls,
                 incoherent_impls,
@@ -2009,6 +2011,12 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
         self.lazy_array(deps.iter().map(|(_, dep)| dep))
     }
 
+    fn encode_target_modifiers(&mut self) -> LazyArray<TargetModifier> {
+        empty_proc_macro!(self);
+        let tcx = self.tcx;
+        self.lazy_array(tcx.sess.opts.gather_target_modifiers())
+    }
+
     fn encode_lib_features(&mut self) -> LazyArray<(Symbol, FeatureStability)> {
         empty_proc_macro!(self);
         let tcx = self.tcx;
diff --git a/compiler/rustc_metadata/src/rmeta/mod.rs b/compiler/rustc_metadata/src/rmeta/mod.rs
index 4f9cdc9a474bd..fd0f9bd05b31c 100644
--- a/compiler/rustc_metadata/src/rmeta/mod.rs
+++ b/compiler/rustc_metadata/src/rmeta/mod.rs
@@ -1,7 +1,7 @@
 use std::marker::PhantomData;
 use std::num::NonZero;
 
-pub(crate) use decoder::{CrateMetadata, CrateNumMap, MetadataBlob};
+pub(crate) use decoder::{CrateMetadata, CrateNumMap, MetadataBlob, TargetModifiers};
 use decoder::{DecodeContext, Metadata};
 use def_path_hash_map::DefPathHashMapRef;
 use encoder::EncodeContext;
@@ -32,7 +32,7 @@ use rustc_middle::ty::{
 use rustc_middle::util::Providers;
 use rustc_middle::{mir, trivially_parameterized_over_tcx};
 use rustc_serialize::opaque::FileEncoder;
-use rustc_session::config::SymbolManglingVersion;
+use rustc_session::config::{SymbolManglingVersion, TargetModifier};
 use rustc_session::cstore::{CrateDepKind, ForeignModule, LinkagePreference, NativeLib};
 use rustc_span::edition::Edition;
 use rustc_span::hygiene::{ExpnIndex, MacroKind, SyntaxContextData};
@@ -282,6 +282,7 @@ pub(crate) struct CrateRoot {
     def_path_hash_map: LazyValue<DefPathHashMapRef<'static>>,
 
     source_map: LazyTable<u32, Option<LazyValue<rustc_span::SourceFile>>>,
+    target_modifiers: LazyArray<TargetModifier>,
 
     compiler_builtins: bool,
     needs_allocator: bool,
diff --git a/compiler/rustc_middle/src/ty/parameterized.rs b/compiler/rustc_middle/src/ty/parameterized.rs
index 6b6c6f3c72feb..8eaf0a58f7086 100644
--- a/compiler/rustc_middle/src/ty/parameterized.rs
+++ b/compiler/rustc_middle/src/ty/parameterized.rs
@@ -101,6 +101,7 @@ trivially_parameterized_over_tcx! {
     rustc_session::cstore::ForeignModule,
     rustc_session::cstore::LinkagePreference,
     rustc_session::cstore::NativeLib,
+    rustc_session::config::TargetModifier,
     rustc_span::ExpnData,
     rustc_span::ExpnHash,
     rustc_span::ExpnId,
diff --git a/compiler/rustc_session/src/config.rs b/compiler/rustc_session/src/config.rs
index 5192ad61af2b1..48c730192959d 100644
--- a/compiler/rustc_session/src/config.rs
+++ b/compiler/rustc_session/src/config.rs
@@ -1198,6 +1198,7 @@ impl Default for Options {
             color: ColorConfig::Auto,
             logical_env: FxIndexMap::default(),
             verbose: false,
+            target_modifiers: BTreeMap::default(),
         }
     }
 }
@@ -2341,14 +2342,16 @@ pub fn build_session_options(early_dcx: &mut EarlyDiagCtxt, matches: &getopts::M
     let crate_types = parse_crate_types_from_list(unparsed_crate_types)
         .unwrap_or_else(|e| early_dcx.early_fatal(e));
 
-    let mut unstable_opts = UnstableOptions::build(early_dcx, matches);
+    let mut target_modifiers = BTreeMap::<OptionsTargetModifiers, String>::new();
+
+    let mut unstable_opts = UnstableOptions::build(early_dcx, matches, &mut target_modifiers);
     let (lint_opts, describe_lints, lint_cap) = get_cmd_lint_options(early_dcx, matches);
 
     check_error_format_stability(early_dcx, &unstable_opts, error_format);
 
     let output_types = parse_output_types(early_dcx, &unstable_opts, matches);
 
-    let mut cg = CodegenOptions::build(early_dcx, matches);
+    let mut cg = CodegenOptions::build(early_dcx, matches, &mut target_modifiers);
     let (disable_local_thinlto, codegen_units) = should_override_cgus_and_disable_thinlto(
         early_dcx,
         &output_types,
@@ -2619,6 +2622,7 @@ pub fn build_session_options(early_dcx: &mut EarlyDiagCtxt, matches: &getopts::M
         color,
         logical_env,
         verbose,
+        target_modifiers,
     }
 }
 
diff --git a/compiler/rustc_session/src/lib.rs b/compiler/rustc_session/src/lib.rs
index dcf86d1a4089f..924350b8cbcdf 100644
--- a/compiler/rustc_session/src/lib.rs
+++ b/compiler/rustc_session/src/lib.rs
@@ -4,6 +4,9 @@
 #![feature(let_chains)]
 #![feature(map_many_mut)]
 #![feature(rustc_attrs)]
+// To generate CodegenOptionsTargetModifiers and UnstableOptionsTargetModifiers enums
+// with macro_rules, it is necessary to use recursive mechanic ("Incremental TT Munchers").
+#![recursion_limit = "256"]
 #![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
diff --git a/compiler/rustc_session/src/options.rs b/compiler/rustc_session/src/options.rs
index 3af6df6301774..c5838a990655b 100644
--- a/compiler/rustc_session/src/options.rs
+++ b/compiler/rustc_session/src/options.rs
@@ -10,6 +10,7 @@ use rustc_data_structures::profiling::TimePassesFormat;
 use rustc_data_structures::stable_hasher::Hash64;
 use rustc_errors::{ColorConfig, LanguageIdentifier, TerminalUrl};
 use rustc_feature::UnstableFeatures;
+use rustc_macros::{Decodable, Encodable};
 use rustc_span::edition::Edition;
 use rustc_span::{RealFileName, SourceFileHashAlgorithm};
 use rustc_target::spec::{
@@ -59,18 +60,194 @@ macro_rules! hash_substruct {
     };
 }
 
+/// Extended target modifier info.
+/// For example, when external target modifier is '-Zregparm=2':
+/// Target modifier enum value + user value ('2') from external crate
+/// is converted into description: prefix ('Z'), name ('regparm'), tech value ('Some(2)').
+pub struct ExtendedTargetModifierInfo {
+    /// Flag prefix (usually, 'C' for codegen flags or 'Z' for unstable flags)
+    pub prefix: String,
+    /// Flag name
+    pub name: String,
+    /// Flag parsed technical value
+    pub tech_value: String,
+}
+
+/// A recorded -Zopt_name=opt_value (or -Copt_name=opt_value)
+/// which alter the ABI or effectiveness of exploit mitigations.
+#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord, Encodable, Decodable)]
+pub struct TargetModifier {
+    /// Option enum value
+    pub opt: OptionsTargetModifiers,
+    /// User-provided option value (before parsing)
+    pub value_name: String,
+}
+
+impl TargetModifier {
+    pub fn extend(&self) -> ExtendedTargetModifierInfo {
+        self.opt.reparse(&self.value_name)
+    }
+}
+
+fn tmod_push_impl(
+    opt: OptionsTargetModifiers,
+    tmod_vals: &BTreeMap<OptionsTargetModifiers, String>,
+    tmods: &mut Vec<TargetModifier>,
+) {
+    tmods.push(TargetModifier { opt, value_name: tmod_vals.get(&opt).cloned().unwrap_or_default() })
+}
+
+macro_rules! tmod_push {
+    ($struct_name:ident, $tmod_enum_name:ident, $opt_name:ident, $mods:expr, $tmod_vals:expr) => {
+        tmod_push_impl(
+            OptionsTargetModifiers::$struct_name($tmod_enum_name::$opt_name),
+            $tmod_vals,
+            $mods,
+        );
+    };
+}
+
+macro_rules! gather_tmods {
+    ($struct_name:ident, $tmod_enum_name:ident, $opt_name:ident, $opt_expr:expr, $mods:expr, $tmod_vals:expr,
+        [SUBSTRUCT], [TARGET_MODIFIER]) => {
+        compile_error!("SUBSTRUCT can't be target modifier");
+    };
+    ($struct_name:ident, $tmod_enum_name:ident, $opt_name:ident, $opt_expr:expr, $mods:expr, $tmod_vals:expr,
+        [UNTRACKED], [TARGET_MODIFIER]) => {
+        tmod_push!($struct_name, $tmod_enum_name, $opt_name, $mods, $tmod_vals)
+    };
+    ($struct_name:ident, $tmod_enum_name:ident, $opt_name:ident, $opt_expr:expr, $mods:expr, $tmod_vals:expr,
+        [TRACKED], [TARGET_MODIFIER]) => {
+        tmod_push!($struct_name, $tmod_enum_name, $opt_name, $mods, $tmod_vals)
+    };
+    ($struct_name:ident, $tmod_enum_name:ident, $opt_name:ident, $opt_expr:expr, $mods:expr, $tmod_vals:expr,
+        [TRACKED_NO_CRATE_HASH], [TARGET_MODIFIER]) => {
+        tmod_push!($struct_name, $tmod_enum_name, $opt_name, $mods, $tmod_vals)
+    };
+    ($struct_name:ident, $tmod_enum_name:ident, $opt_name:ident, $opt_expr:expr, $mods:expr, $tmod_vals:expr,
+        [SUBSTRUCT], []) => {
+        $opt_expr.gather_target_modifiers($mods, $tmod_vals);
+    };
+    ($struct_name:ident, $tmod_enum_name:ident, $opt_name:ident, $opt_expr:expr, $mods:expr, $tmod_vals:expr,
+        [UNTRACKED], []) => {{}};
+    ($struct_name:ident, $tmod_enum_name:ident, $opt_name:ident, $opt_expr:expr, $mods:expr, $tmod_vals:expr,
+        [TRACKED], []) => {{}};
+    ($struct_name:ident, $tmod_enum_name:ident, $opt_name:ident, $opt_expr:expr, $mods:expr, $tmod_vals:expr,
+        [TRACKED_NO_CRATE_HASH], []) => {{}};
+}
+
+macro_rules! gather_tmods_top_level {
+    ($_opt_name:ident, $opt_expr:expr, $mods:expr, $tmod_vals:expr, [SUBSTRUCT $substruct_enum:ident]) => {
+        $opt_expr.gather_target_modifiers($mods, $tmod_vals);
+    };
+    ($opt_name:ident, $opt_expr:expr, $mods:expr, $tmod_vals:expr, [$non_substruct:ident TARGET_MODIFIER]) => {
+        compile_error!("Top level option can't be target modifier");
+    };
+    ($opt_name:ident, $opt_expr:expr, $mods:expr, $tmod_vals:expr, [$non_substruct:ident]) => {};
+}
+
+/// Macro for generating OptionsTargetsModifiers top-level enum with impl.
+/// Will generate something like:
+/// ```rust,ignore (illustrative)
+/// pub enum OptionsTargetModifiers {
+///     CodegenOptions(CodegenOptionsTargetModifiers),
+///     UnstableOptions(UnstableOptionsTargetModifiers),
+/// }
+/// impl OptionsTargetModifiers {
+///     pub fn reparse(&self, user_value: &str) -> ExtendedTargetModifierInfo {
+///         match self {
+///             Self::CodegenOptions(v) => v.reparse(user_value),
+///             Self::UnstableOptions(v) => v.reparse(user_value),
+///         }
+///     }
+///     pub fn is_target_modifier(flag_name: &str) -> bool {
+///         CodegenOptionsTargetModifiers::is_target_modifier(flag_name) ||
+///         UnstableOptionsTargetModifiers::is_target_modifier(flag_name)
+///     }
+/// }
+/// ```
+macro_rules! top_level_tmod_enum {
+    ($( {$($optinfo:tt)*} ),* $(,)*) => {
+        top_level_tmod_enum! { @parse {}, (user_value){}; $($($optinfo)*|)* }
+    };
+    // Termination
+    (
+        @parse
+        {$($variant:tt($substruct_enum:tt))*},
+        ($user_value:ident){$($pout:tt)*};
+    ) => {
+        #[allow(non_camel_case_types)]
+        #[derive(PartialEq, Eq, PartialOrd, Ord, Debug, Copy, Clone, Encodable, Decodable)]
+        pub enum OptionsTargetModifiers {
+            $($variant($substruct_enum)),*
+        }
+        impl OptionsTargetModifiers {
+            #[allow(unused_variables)]
+            pub fn reparse(&self, $user_value: &str) -> ExtendedTargetModifierInfo {
+                #[allow(unreachable_patterns)]
+                match self {
+                    $($pout)*
+                    _ => panic!("unknown target modifier option: {:?}", *self)
+                }
+            }
+            pub fn is_target_modifier(flag_name: &str) -> bool {
+                $($substruct_enum::is_target_modifier(flag_name))||*
+            }
+        }
+    };
+    // Adding SUBSTRUCT option group into $eout
+    (
+        @parse {$($eout:tt)*}, ($puser_value:ident){$($pout:tt)*};
+            [SUBSTRUCT $substruct_enum:ident $variant:ident] |
+        $($tail:tt)*
+    ) => {
+        top_level_tmod_enum! {
+            @parse
+            {
+                $($eout)*
+                $variant($substruct_enum)
+            },
+            ($puser_value){
+                $($pout)*
+                Self::$variant(v) => v.reparse($puser_value),
+            };
+            $($tail)*
+        }
+    };
+    // Skipping non-target-modifier and non-substruct
+    (
+        @parse {$($eout:tt)*}, ($puser_value:ident){$($pout:tt)*};
+            [$non_substruct:ident] |
+        $($tail:tt)*
+    ) => {
+        top_level_tmod_enum! {
+            @parse
+            {
+                $($eout)*
+            },
+            ($puser_value){
+                $($pout)*
+            };
+            $($tail)*
+        }
+    };
+}
+
 macro_rules! top_level_options {
     ( $( #[$top_level_attr:meta] )* pub struct Options { $(
         $( #[$attr:meta] )*
-        $opt:ident : $t:ty [$dep_tracking_marker:ident],
+        $opt:ident : $t:ty [$dep_tracking_marker:ident $( $tmod:ident $variant:ident )?],
     )* } ) => (
+        top_level_tmod_enum!( {$([$dep_tracking_marker $($tmod $variant),*])|*} );
+
         #[derive(Clone)]
         $( #[$top_level_attr] )*
         pub struct Options {
             $(
                 $( #[$attr] )*
                 pub $opt: $t
-            ),*
+            ),*,
+            pub target_modifiers: BTreeMap<OptionsTargetModifiers, String>,
         }
 
         impl Options {
@@ -98,6 +275,17 @@ macro_rules! top_level_options {
                 })*
                 hasher.finish()
             }
+
+            pub fn gather_target_modifiers(&self) -> Vec<TargetModifier> {
+                let mut mods = Vec::<TargetModifier>::new();
+                $({
+                    gather_tmods_top_level!($opt,
+                        &self.$opt, &mut mods, &self.target_modifiers,
+                        [$dep_tracking_marker $($tmod),*]);
+                })*
+                mods.sort_by(|a, b| a.opt.cmp(&b.opt));
+                mods
+            }
         }
     );
 }
@@ -165,9 +353,9 @@ top_level_options!(
         #[rustc_lint_opt_deny_field_access("should only be used via `Config::hash_untracked_state`")]
         untracked_state_hash: Hash64 [TRACKED_NO_CRATE_HASH],
 
-        unstable_opts: UnstableOptions [SUBSTRUCT],
+        unstable_opts: UnstableOptions [SUBSTRUCT UnstableOptionsTargetModifiers UnstableOptions],
         prints: Vec<PrintRequest> [UNTRACKED],
-        cg: CodegenOptions [SUBSTRUCT],
+        cg: CodegenOptions [SUBSTRUCT CodegenOptionsTargetModifiers CodegenOptions],
         externs: Externs [UNTRACKED],
         crate_name: Option<String> [TRACKED],
         /// Indicates how the compiler should treat unstable features.
@@ -226,6 +414,98 @@ top_level_options!(
     }
 );
 
+macro_rules! tmod_enum_opt {
+    ($struct_name:ident, $tmod_enum_name:ident, $opt:ident, $v:ident) => {
+        Some(OptionsTargetModifiers::$struct_name($tmod_enum_name::$opt))
+    };
+    ($struct_name:ident, $tmod_enum_name:ident, $opt:ident, ) => {
+        None
+    };
+}
+
+macro_rules! tmod_enum {
+    ($tmod_enum_name:ident, $prefix:expr, $( {$($optinfo:tt)*} ),* $(,)*) => {
+        tmod_enum! { $tmod_enum_name, $prefix, @parse {}, (user_value){}; $($($optinfo)*|)* }
+    };
+    // Termination
+    (
+        $tmod_enum_name:ident, $prefix:expr,
+        @parse
+        {$($eout:tt)*},
+        ($user_value:ident){$($pout:tt)*};
+    ) => {
+        #[allow(non_camel_case_types)]
+        #[derive(PartialEq, Eq, PartialOrd, Ord, Debug, Copy, Clone, Encodable, Decodable)]
+        pub enum $tmod_enum_name {
+            $($eout),*
+        }
+        impl $tmod_enum_name {
+            #[allow(unused_variables)]
+            pub fn reparse(&self, $user_value: &str) -> ExtendedTargetModifierInfo {
+                #[allow(unreachable_patterns)]
+                match self {
+                    $($pout)*
+                    _ => panic!("unknown target modifier option: {:?}", *self)
+                }
+            }
+            pub fn is_target_modifier(flag_name: &str) -> bool {
+                match flag_name.replace('-', "_").as_str() {
+                    $(stringify!($eout) => true,)*
+                    _ => false,
+                }
+            }
+        }
+    };
+    // Adding target-modifier option into $eout
+    (
+        $tmod_enum_name:ident, $prefix:expr,
+        @parse {$($eout:tt)*}, ($puser_value:ident){$($pout:tt)*};
+            $opt:ident, $parse:ident, $t:ty, [TARGET_MODIFIER] |
+        $($tail:tt)*
+    ) => {
+        tmod_enum! {
+            $tmod_enum_name, $prefix,
+            @parse
+            {
+                $($eout)*
+                $opt
+            },
+            ($puser_value){
+                $($pout)*
+                Self::$opt => {
+                    let mut parsed : $t = Default::default();
+                    parse::$parse(&mut parsed, Some($puser_value));
+                    ExtendedTargetModifierInfo {
+                        prefix: $prefix.to_string(),
+                        name: stringify!($opt).to_string().replace('_', "-"),
+                        tech_value: format!("{:?}", parsed),
+                    }
+                },
+            };
+            $($tail)*
+        }
+    };
+    // Skipping non-target-modifier
+    (
+        $tmod_enum_name:ident, $prefix:expr,
+        @parse {$($eout:tt)*}, ($puser_value:ident){$($pout:tt)*};
+            $opt:ident, $parse:ident, $t:ty, [] |
+        $($tail:tt)*
+    ) => {
+        tmod_enum! {
+            $tmod_enum_name, $prefix,
+            @parse
+            {
+                $($eout)*
+            },
+            ($puser_value){
+                $($pout)*
+            };
+            $($tail)*
+        }
+    };
+}
+
 /// Defines all `CodegenOptions`/`DebuggingOptions` fields and parsers all at once. The goal of this
 /// macro is to define an interface that can be programmatically used by the option parser
 /// to initialize the struct without hardcoding field names all over the place.
@@ -235,11 +515,11 @@ top_level_options!(
 /// generated code to parse an option into its respective field in the struct. There are a few
 /// hand-written parsers for parsing specific types of values in this module.
 macro_rules! options {
-    ($struct_name:ident, $stat:ident, $optmod:ident, $prefix:expr, $outputname:expr,
+    ($struct_name:ident, $tmod_enum_name:ident, $stat:ident, $optmod:ident, $prefix:expr, $outputname:expr,
      $($( #[$attr:meta] )* $opt:ident : $t:ty = (
         $init:expr,
         $parse:ident,
-        [$dep_tracking_marker:ident],
+        [$dep_tracking_marker:ident $( $tmod:ident )?],
         $desc:expr
         $(, deprecated_do_nothing: $dnn:literal )?)
      ),* ,) =>
@@ -248,6 +528,8 @@ macro_rules! options {
     #[rustc_lint_opt_ty]
     pub struct $struct_name { $( $( #[$attr] )* pub $opt: $t),* }
 
+    tmod_enum!( $tmod_enum_name, $prefix, {$($opt, $parse, $t, [$($tmod),*])|*} );
+
     impl Default for $struct_name {
         fn default() -> $struct_name {
             $struct_name { $($opt: $init),* }
@@ -258,8 +540,9 @@ macro_rules! options {
         pub fn build(
             early_dcx: &EarlyDiagCtxt,
             matches: &getopts::Matches,
+            target_modifiers: &mut BTreeMap<OptionsTargetModifiers, String>,
         ) -> $struct_name {
-            build_options(early_dcx, matches, $stat, $prefix, $outputname)
+            build_options(early_dcx, matches, target_modifiers, $stat, $prefix, $outputname)
         }
 
         fn dep_tracking_hash(&self, for_crate_hash: bool, error_format: ErrorOutputType) -> u64 {
@@ -279,11 +562,23 @@ macro_rules! options {
                                         );
             hasher.finish()
         }
+
+        pub fn gather_target_modifiers(
+            &self,
+            _mods: &mut Vec<TargetModifier>,
+            _tmod_vals: &BTreeMap<OptionsTargetModifiers, String>,
+        ) {
+            $({
+                gather_tmods!($struct_name, $tmod_enum_name, $opt, &self.$opt, _mods, _tmod_vals,
+                    [$dep_tracking_marker], [$($tmod),*]);
+            })*
+        }
     }
 
     pub const $stat: OptionDescrs<$struct_name> =
         &[ $( OptionDesc{ name: stringify!($opt), setter: $optmod::$opt,
-            type_desc: desc::$parse, desc: $desc, is_deprecated_and_do_nothing: false $( || $dnn )? } ),* ];
+            type_desc: desc::$parse, desc: $desc, is_deprecated_and_do_nothing: false $( || $dnn )?,
+            tmod: tmod_enum_opt!($struct_name, $tmod_enum_name, $opt, $($tmod),*) } ),* ];
 
     mod $optmod {
     $(
@@ -328,6 +623,7 @@ pub struct OptionDesc<O> {
     // description for option from options table
     desc: &'static str,
     is_deprecated_and_do_nothing: bool,
+    tmod: Option<OptionsTargetModifiers>,
 }
 
 impl<O> OptionDesc<O> {
@@ -344,6 +640,7 @@ impl<O> OptionDesc<O> {
 fn build_options<O: Default>(
     early_dcx: &EarlyDiagCtxt,
     matches: &getopts::Matches,
+    target_modifiers: &mut BTreeMap<OptionsTargetModifiers, String>,
     descrs: OptionDescrs<O>,
     prefix: &str,
     outputname: &str,
@@ -357,7 +654,14 @@ fn build_options<O: Default>(
 
         let option_to_lookup = key.replace('-', "_");
         match descrs.iter().find(|opt_desc| opt_desc.name == option_to_lookup) {
-            Some(OptionDesc { name: _, setter, type_desc, desc, is_deprecated_and_do_nothing }) => {
+            Some(OptionDesc {
+                name: _,
+                setter,
+                type_desc,
+                desc,
+                is_deprecated_and_do_nothing,
+                tmod,
+            }) => {
                 if *is_deprecated_and_do_nothing {
                     // deprecation works for prefixed options only
                     assert!(!prefix.is_empty());
@@ -377,6 +681,11 @@ fn build_options<O: Default>(
                         ),
                     }
                 }
+                if let Some(tmod) = *tmod
+                    && let Some(value) = value
+                {
+                    target_modifiers.insert(tmod, value.to_string());
+                }
             }
             None => early_dcx.early_fatal(format!("unknown {outputname} option: `{key}`")),
         }
@@ -1581,7 +1890,7 @@ pub mod parse {
 }
 
 options! {
-    CodegenOptions, CG_OPTIONS, cgopts, "C", "codegen",
+    CodegenOptions, CodegenOptionsTargetModifiers, CG_OPTIONS, cgopts, "C", "codegen",
 
     // If you add a new option, please update:
     // - compiler/rustc_interface/src/tests.rs
@@ -1712,6 +2021,8 @@ options! {
     target_feature: String = (String::new(), parse_target_feature, [TRACKED],
         "target specific attributes. (`rustc --print target-features` for details). \
         This feature is unsafe."),
+    unsafe_allow_abi_mismatch: Vec<String> = (Vec::new(), parse_comma_list, [UNTRACKED],
+        "Allow incompatible target modifiers in dependency crates (comma separated list)"),
     // tidy-alphabetical-end
 
     // If you add a new option, please update:
@@ -1720,7 +2031,7 @@ options! {
 }
 
 options! {
-    UnstableOptions, Z_OPTIONS, dbopts, "Z", "unstable",
+    UnstableOptions, UnstableOptionsTargetModifiers, Z_OPTIONS, dbopts, "Z", "unstable",
 
     // If you add a new option, please update:
     // - compiler/rustc_interface/src/tests.rs
@@ -2052,10 +2363,10 @@ options! {
         "enable queries of the dependency graph for regression testing (default: no)"),
     randomize_layout: bool = (false, parse_bool, [TRACKED],
         "randomize the layout of types (default: no)"),
-    reg_struct_return: bool = (false, parse_bool, [TRACKED],
+    reg_struct_return: bool = (false, parse_bool, [TRACKED TARGET_MODIFIER],
         "On x86-32 targets, it overrides the default ABI to return small structs in registers.
         It is UNSOUND to link together crates that use different values for this flag!"),
-    regparm: Option<u32> = (None, parse_opt_number, [TRACKED],
+    regparm: Option<u32> = (None, parse_opt_number, [TRACKED TARGET_MODIFIER],
         "On x86-32 targets, setting this to N causes the compiler to pass N arguments \
         in registers EAX, EDX, and ECX instead of on the stack for\
         \"C\", \"cdecl\", and \"stdcall\" fn.\
diff --git a/src/librustdoc/config.rs b/src/librustdoc/config.rs
index 80bc6cebd2aa9..7437f2045c59c 100644
--- a/src/librustdoc/config.rs
+++ b/src/librustdoc/config.rs
@@ -9,8 +9,8 @@ use rustc_data_structures::fx::FxIndexMap;
 use rustc_errors::DiagCtxtHandle;
 use rustc_session::config::{
     self, CodegenOptions, CrateType, ErrorOutputType, Externs, Input, JsonUnusedExterns,
-    UnstableOptions, get_cmd_lint_options, nightly_options, parse_crate_types_from_list,
-    parse_externs, parse_target_triple,
+    OptionsTargetModifiers, UnstableOptions, get_cmd_lint_options, nightly_options,
+    parse_crate_types_from_list, parse_externs, parse_target_triple,
 };
 use rustc_session::lint::Level;
 use rustc_session::search_paths::SearchPath;
@@ -387,8 +387,9 @@ impl Options {
             config::parse_error_format(early_dcx, matches, color, json_color, json_rendered);
         let diagnostic_width = matches.opt_get("diagnostic-width").unwrap_or_default();
 
-        let codegen_options = CodegenOptions::build(early_dcx, matches);
-        let unstable_opts = UnstableOptions::build(early_dcx, matches);
+        let mut target_modifiers = BTreeMap::<OptionsTargetModifiers, String>::new();
+        let codegen_options = CodegenOptions::build(early_dcx, matches, &mut target_modifiers);
+        let unstable_opts = UnstableOptions::build(early_dcx, matches, &mut target_modifiers);
 
         let remap_path_prefix = match parse_remap_path_prefix(matches) {
             Ok(prefix_mappings) => prefix_mappings,
diff --git a/tests/ui/target_modifiers/auxiliary/default_reg_struct_return.rs b/tests/ui/target_modifiers/auxiliary/default_reg_struct_return.rs
new file mode 100644
index 0000000000000..6c871fe3a1030
--- /dev/null
+++ b/tests/ui/target_modifiers/auxiliary/default_reg_struct_return.rs
@@ -0,0 +1,14 @@
+//@ compile-flags: --target i686-unknown-linux-gnu -Cpanic=abort
+//@ needs-llvm-components: x86
+#![crate_type = "lib"]
+#![no_core]
+#![feature(no_core, lang_items, repr_simd)]
+
+#[lang = "sized"]
+trait Sized {}
+#[lang = "copy"]
+trait Copy {}
+
+pub fn somefun() {}
+
+pub struct S;
diff --git a/tests/ui/target_modifiers/auxiliary/wrong_regparm.rs b/tests/ui/target_modifiers/auxiliary/wrong_regparm.rs
new file mode 100644
index 0000000000000..50cd64d2df4d1
--- /dev/null
+++ b/tests/ui/target_modifiers/auxiliary/wrong_regparm.rs
@@ -0,0 +1,14 @@
+//@ compile-flags: --target i686-unknown-linux-gnu -Zregparm=2 -Cpanic=abort
+//@ needs-llvm-components: x86
+#![crate_type = "lib"]
+#![no_core]
+#![feature(no_core, lang_items, repr_simd)]
+
+#[lang = "sized"]
+trait Sized {}
+#[lang = "copy"]
+trait Copy {}
+
+pub fn somefun() {}
+
+pub struct S;
diff --git a/tests/ui/target_modifiers/auxiliary/wrong_regparm_and_ret.rs b/tests/ui/target_modifiers/auxiliary/wrong_regparm_and_ret.rs
new file mode 100644
index 0000000000000..4d1e02d54fc52
--- /dev/null
+++ b/tests/ui/target_modifiers/auxiliary/wrong_regparm_and_ret.rs
@@ -0,0 +1,14 @@
+//@ compile-flags: --target i686-unknown-linux-gnu -Zregparm=2 -Zreg-struct-return=true -Cpanic=abort
+//@ needs-llvm-components: x86
+#![crate_type = "lib"]
+#![no_core]
+#![feature(no_core, lang_items, repr_simd)]
+
+#[lang = "sized"]
+trait Sized {}
+#[lang = "copy"]
+trait Copy {}
+
+pub fn somefun() {}
+
+pub struct S;
diff --git a/tests/ui/target_modifiers/defaults_check.error.stderr b/tests/ui/target_modifiers/defaults_check.error.stderr
new file mode 100644
index 0000000000000..3f67ca8d4bead
--- /dev/null
+++ b/tests/ui/target_modifiers/defaults_check.error.stderr
@@ -0,0 +1,13 @@
+error: mixing `-Zreg-struct-return` will cause an ABI mismatch in crate `defaults_check`
+  --> $DIR/defaults_check.rs:13:1
+   |
+LL | #![crate_type = "lib"]
+   | ^
+   |
+   = help: the `-Zreg-struct-return` flag modifies the ABI so Rust crates compiled with different values of this flag cannot be used together safely
+   = note: `-Zreg-struct-return=true` in this crate is incompatible with `-Zreg-struct-return=` in dependency `default_reg_struct_return`
+   = help: set `-Zreg-struct-return=` in this crate or `-Zreg-struct-return=true` in `default_reg_struct_return`
+   = help: if you are sure this will not cause problems, you may use `-Cunsafe-allow-abi-mismatch=reg-struct-return` to silence this error
+
+error: aborting due to 1 previous error
+
diff --git a/tests/ui/target_modifiers/defaults_check.rs b/tests/ui/target_modifiers/defaults_check.rs
new file mode 100644
index 0000000000000..6cca34c24187f
--- /dev/null
+++ b/tests/ui/target_modifiers/defaults_check.rs
@@ -0,0 +1,20 @@
+// Tests that default unspecified target modifier value in dependency crate is ok linked
+// with the same value, explicitly specified
+//@ aux-crate:default_reg_struct_return=default_reg_struct_return.rs
+//@ compile-flags: --target i686-unknown-linux-gnu -Cpanic=abort
+//@ revisions:error ok ok_explicit
+//@[ok] compile-flags:
+//@[ok_explicit] compile-flags: -Zreg-struct-return=false
+//@[error] compile-flags: -Zreg-struct-return=true
+//@ needs-llvm-components: x86
+//@[ok] build-pass
+//@[ok_explicit] build-pass
+
+#![crate_type = "lib"]
+//[error]~^ ERROR mixing `-Zreg-struct-return` will cause an ABI mismatch in crate `defaults_check`
+#![no_core]
+#![feature(no_core, lang_items, repr_simd)]
+
+fn foo() {
+    default_reg_struct_return::somefun();
+}
diff --git a/tests/ui/target_modifiers/incompatible_regparm.allow_no_value.stderr b/tests/ui/target_modifiers/incompatible_regparm.allow_no_value.stderr
new file mode 100644
index 0000000000000..8597332825b56
--- /dev/null
+++ b/tests/ui/target_modifiers/incompatible_regparm.allow_no_value.stderr
@@ -0,0 +1,2 @@
+error: codegen option `unsafe-allow-abi-mismatch` requires a comma-separated list of strings (C unsafe-allow-abi-mismatch=<value>)
+
diff --git a/tests/ui/target_modifiers/incompatible_regparm.error_generated.stderr b/tests/ui/target_modifiers/incompatible_regparm.error_generated.stderr
new file mode 100644
index 0000000000000..039aeb6fb3cff
--- /dev/null
+++ b/tests/ui/target_modifiers/incompatible_regparm.error_generated.stderr
@@ -0,0 +1,13 @@
+error: mixing `-Zregparm` will cause an ABI mismatch in crate `incompatible_regparm`
+  --> $DIR/incompatible_regparm.rs:10:1
+   |
+LL | #![crate_type = "lib"]
+   | ^
+   |
+   = help: the `-Zregparm` flag modifies the ABI so Rust crates compiled with different values of this flag cannot be used together safely
+   = note: `-Zregparm=1` in this crate is incompatible with `-Zregparm=2` in dependency `wrong_regparm`
+   = help: set `-Zregparm=2` in this crate or `-Zregparm=1` in `wrong_regparm`
+   = help: if you are sure this will not cause problems, you may use `-Cunsafe-allow-abi-mismatch=regparm` to silence this error
+
+error: aborting due to 1 previous error
+
diff --git a/tests/ui/target_modifiers/incompatible_regparm.rs b/tests/ui/target_modifiers/incompatible_regparm.rs
new file mode 100644
index 0000000000000..ec1b21bedaa70
--- /dev/null
+++ b/tests/ui/target_modifiers/incompatible_regparm.rs
@@ -0,0 +1,17 @@
+//@ aux-crate:wrong_regparm=wrong_regparm.rs
+//@ compile-flags: --target i686-unknown-linux-gnu -Zregparm=1 -Cpanic=abort
+//@ needs-llvm-components: x86
+//@ revisions:error_generated allow_regparm_mismatch allow_no_value
+
+//@[allow_regparm_mismatch] compile-flags: -Cunsafe-allow-abi-mismatch=regparm
+//@[allow_regparm_mismatch] build-pass
+//@[allow_no_value] compile-flags: -Cunsafe-allow-abi-mismatch
+
+#![crate_type = "lib"]
+//[error_generated]~^ ERROR mixing `-Zregparm` will cause an ABI mismatch in crate `incompatible_regparm`
+#![no_core]
+#![feature(no_core, lang_items, repr_simd)]
+
+fn foo() {
+    wrong_regparm::somefun();
+}
diff --git a/tests/ui/target_modifiers/two_flags.rs b/tests/ui/target_modifiers/two_flags.rs
new file mode 100644
index 0000000000000..76484f9c96960
--- /dev/null
+++ b/tests/ui/target_modifiers/two_flags.rs
@@ -0,0 +1,17 @@
+//@ aux-crate:wrong_regparm_and_ret=wrong_regparm_and_ret.rs
+//@ compile-flags: --target i686-unknown-linux-gnu -Cpanic=abort
+//@ needs-llvm-components: x86
+//@ revisions:two_allowed unknown_allowed
+
+//@[two_allowed] compile-flags: -Cunsafe-allow-abi-mismatch=regparm,reg-struct-return
+//@[two_allowed] build-pass
+//@[unknown_allowed] compile-flags: -Cunsafe-allow-abi-mismatch=unknown_flag -Zregparm=2 -Zreg-struct-return=true
+
+#![crate_type = "lib"]
+//[unknown_allowed]~^ ERROR unknown target modifier `unknown_flag`, requested by `-Cunsafe-allow-abi-mismatch=unknown_flag`
+#![no_core]
+#![feature(no_core, lang_items, repr_simd)]
+
+fn foo() {
+    wrong_regparm_and_ret::somefun();
+}
diff --git a/tests/ui/target_modifiers/two_flags.unknown_allowed.stderr b/tests/ui/target_modifiers/two_flags.unknown_allowed.stderr
new file mode 100644
index 0000000000000..eb5bede67ccb2
--- /dev/null
+++ b/tests/ui/target_modifiers/two_flags.unknown_allowed.stderr
@@ -0,0 +1,8 @@
+error: unknown target modifier `unknown_flag`, requested by `-Cunsafe-allow-abi-mismatch=unknown_flag`
+  --> $DIR/two_flags.rs:10:1
+   |
+LL | #![crate_type = "lib"]
+   | ^
+
+error: aborting due to 1 previous error
+

From a745b602c352c84b852a9bd0d134691ebc7c7a2c Mon Sep 17 00:00:00 2001
From: jyn <github@jyn.dev>
Date: Wed, 22 Jan 2025 18:13:53 -0500
Subject: [PATCH 10/17] Only use linker-flavor=gnu-cc if we're actually going
 to compare the output

It doesn't exist on MacOS.

It's strange to me why the flavor is platform specific; I would expect you to be able to use any userspace on any OS? But trying to do this outside of Linux is already kinda weird, so.
---
 tests/run-make/linker-warning/rmake.rs | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/tests/run-make/linker-warning/rmake.rs b/tests/run-make/linker-warning/rmake.rs
index 88e467e6cce3f..f1a97af75d8af 100644
--- a/tests/run-make/linker-warning/rmake.rs
+++ b/tests/run-make/linker-warning/rmake.rs
@@ -7,10 +7,13 @@ fn run_rustc() -> Rustc {
         // NOTE: `link-self-contained` can vary depending on config.toml.
         // Make sure we use a consistent value.
         .arg("-Clink-self-contained=-linker")
-        .arg("-Clinker-flavor=gnu-cc")
         .arg("-Zunstable-options")
         .output("main")
         .linker("./fake-linker");
+    if run_make_support::target() == "x86_64-unknown-linux-gnu" {
+        // The value of `rust.lld` is different between CI and locally. Override it explicitly.
+        rustc.arg("-Clinker-flavor=gnu-cc");
+    }
     rustc
 }
 

From aaccb71da9f0954ee5433f61ae8274b29f6da1c5 Mon Sep 17 00:00:00 2001
From: Nikita Popov <npopov@redhat.com>
Date: Mon, 20 Jan 2025 11:38:48 +0100
Subject: [PATCH 11/17] Fix sparcv8plus test on LLVM 20

Split this into two tests, one for LLVM 19 and one for LLVM 20.
---
 tests/ui/abi/sparcv8plus-llvm19.rs            | 43 +++++++++++++++++++
 tests/ui/abi/sparcv8plus-llvm19.sparc.stderr  |  8 ++++
 .../sparcv8plus-llvm19.sparc_cpu_v9.stderr    |  8 ++++
 ...-llvm19.sparc_cpu_v9_feature_v8plus.stderr |  8 ++++
 ...cv8plus-llvm19.sparc_feature_v8plus.stderr |  8 ++++
 .../abi/sparcv8plus-llvm19.sparcv8plus.stderr |  8 ++++
 tests/ui/abi/sparcv8plus.rs                   |  6 +--
 tests/ui/abi/sparcv8plus.sparc_cpu_v9.stderr  |  6 +--
 ...cv8plus.sparc_cpu_v9_feature_v8plus.stderr |  2 +-
 .../sparcv8plus.sparc_feature_v8plus.stderr   |  2 +-
 tests/ui/abi/sparcv8plus.sparcv8plus.stderr   |  2 +-
 11 files changed, 92 insertions(+), 9 deletions(-)
 create mode 100644 tests/ui/abi/sparcv8plus-llvm19.rs
 create mode 100644 tests/ui/abi/sparcv8plus-llvm19.sparc.stderr
 create mode 100644 tests/ui/abi/sparcv8plus-llvm19.sparc_cpu_v9.stderr
 create mode 100644 tests/ui/abi/sparcv8plus-llvm19.sparc_cpu_v9_feature_v8plus.stderr
 create mode 100644 tests/ui/abi/sparcv8plus-llvm19.sparc_feature_v8plus.stderr
 create mode 100644 tests/ui/abi/sparcv8plus-llvm19.sparcv8plus.stderr

diff --git a/tests/ui/abi/sparcv8plus-llvm19.rs b/tests/ui/abi/sparcv8plus-llvm19.rs
new file mode 100644
index 0000000000000..a884e5ca06f10
--- /dev/null
+++ b/tests/ui/abi/sparcv8plus-llvm19.rs
@@ -0,0 +1,43 @@
+//@ revisions: sparc sparcv8plus sparc_cpu_v9 sparc_feature_v8plus sparc_cpu_v9_feature_v8plus
+//@[sparc] compile-flags: --target sparc-unknown-none-elf
+//@[sparc] needs-llvm-components: sparc
+//@[sparcv8plus] compile-flags: --target sparc-unknown-linux-gnu
+//@[sparcv8plus] needs-llvm-components: sparc
+//@[sparc_cpu_v9] compile-flags: --target sparc-unknown-none-elf -C target-cpu=v9
+//@[sparc_cpu_v9] needs-llvm-components: sparc
+//@[sparc_feature_v8plus] compile-flags: --target sparc-unknown-none-elf -C target-feature=+v8plus
+//@[sparc_feature_v8plus] needs-llvm-components: sparc
+//@[sparc_cpu_v9_feature_v8plus] compile-flags: --target sparc-unknown-none-elf -C target-cpu=v9 -C target-feature=+v8plus
+//@[sparc_cpu_v9_feature_v8plus] needs-llvm-components: sparc
+//@ exact-llvm-major-version: 19
+
+#![crate_type = "rlib"]
+#![feature(no_core, rustc_attrs, lang_items)]
+#![no_core]
+
+#[lang = "sized"]
+trait Sized {}
+#[lang = "copy"]
+trait Copy {}
+
+#[rustc_builtin_macro]
+macro_rules! compile_error {
+    () => {};
+}
+
+#[cfg(all(not(target_feature = "v8plus"), not(target_feature = "v9")))]
+compile_error!("-v8plus,-v9");
+//[sparc]~^ ERROR -v8plus,-v9
+
+// FIXME: sparc_cpu_v9 should be in "-v8plus,+v9" group (fixed in LLVM 20)
+#[cfg(all(target_feature = "v8plus", target_feature = "v9"))]
+compile_error!("+v8plus,+v9");
+//[sparcv8plus,sparc_cpu_v9_feature_v8plus,sparc_cpu_v9]~^ ERROR +v8plus,+v9
+
+// FIXME: should be rejected
+#[cfg(all(target_feature = "v8plus", not(target_feature = "v9")))]
+compile_error!("+v8plus,-v9 (FIXME)");
+//[sparc_feature_v8plus]~^ ERROR +v8plus,-v9 (FIXME)
+
+#[cfg(all(not(target_feature = "v8plus"), target_feature = "v9"))]
+compile_error!("-v8plus,+v9");
diff --git a/tests/ui/abi/sparcv8plus-llvm19.sparc.stderr b/tests/ui/abi/sparcv8plus-llvm19.sparc.stderr
new file mode 100644
index 0000000000000..7eedf26135f54
--- /dev/null
+++ b/tests/ui/abi/sparcv8plus-llvm19.sparc.stderr
@@ -0,0 +1,8 @@
+error: -v8plus,-v9
+  --> $DIR/sparcv8plus-llvm19.rs:29:1
+   |
+LL | compile_error!("-v8plus,-v9");
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+
diff --git a/tests/ui/abi/sparcv8plus-llvm19.sparc_cpu_v9.stderr b/tests/ui/abi/sparcv8plus-llvm19.sparc_cpu_v9.stderr
new file mode 100644
index 0000000000000..ac61df3567808
--- /dev/null
+++ b/tests/ui/abi/sparcv8plus-llvm19.sparc_cpu_v9.stderr
@@ -0,0 +1,8 @@
+error: +v8plus,+v9
+  --> $DIR/sparcv8plus-llvm19.rs:34:1
+   |
+LL | compile_error!("+v8plus,+v9");
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+
diff --git a/tests/ui/abi/sparcv8plus-llvm19.sparc_cpu_v9_feature_v8plus.stderr b/tests/ui/abi/sparcv8plus-llvm19.sparc_cpu_v9_feature_v8plus.stderr
new file mode 100644
index 0000000000000..ac61df3567808
--- /dev/null
+++ b/tests/ui/abi/sparcv8plus-llvm19.sparc_cpu_v9_feature_v8plus.stderr
@@ -0,0 +1,8 @@
+error: +v8plus,+v9
+  --> $DIR/sparcv8plus-llvm19.rs:34:1
+   |
+LL | compile_error!("+v8plus,+v9");
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+
diff --git a/tests/ui/abi/sparcv8plus-llvm19.sparc_feature_v8plus.stderr b/tests/ui/abi/sparcv8plus-llvm19.sparc_feature_v8plus.stderr
new file mode 100644
index 0000000000000..1bf7a3ad76a83
--- /dev/null
+++ b/tests/ui/abi/sparcv8plus-llvm19.sparc_feature_v8plus.stderr
@@ -0,0 +1,8 @@
+error: +v8plus,-v9 (FIXME)
+  --> $DIR/sparcv8plus-llvm19.rs:39:1
+   |
+LL | compile_error!("+v8plus,-v9 (FIXME)");
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+
diff --git a/tests/ui/abi/sparcv8plus-llvm19.sparcv8plus.stderr b/tests/ui/abi/sparcv8plus-llvm19.sparcv8plus.stderr
new file mode 100644
index 0000000000000..ac61df3567808
--- /dev/null
+++ b/tests/ui/abi/sparcv8plus-llvm19.sparcv8plus.stderr
@@ -0,0 +1,8 @@
+error: +v8plus,+v9
+  --> $DIR/sparcv8plus-llvm19.rs:34:1
+   |
+LL | compile_error!("+v8plus,+v9");
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+
diff --git a/tests/ui/abi/sparcv8plus.rs b/tests/ui/abi/sparcv8plus.rs
index 108279b34949b..a78ae0cd32889 100644
--- a/tests/ui/abi/sparcv8plus.rs
+++ b/tests/ui/abi/sparcv8plus.rs
@@ -9,7 +9,7 @@
 //@[sparc_feature_v8plus] needs-llvm-components: sparc
 //@[sparc_cpu_v9_feature_v8plus] compile-flags: --target sparc-unknown-none-elf -C target-cpu=v9 -C target-feature=+v8plus
 //@[sparc_cpu_v9_feature_v8plus] needs-llvm-components: sparc
-//@ min-llvm-version: 19
+//@ min-llvm-version: 20
 
 #![crate_type = "rlib"]
 #![feature(no_core, rustc_attrs, lang_items)]
@@ -29,10 +29,9 @@ macro_rules! compile_error {
 compile_error!("-v8plus,-v9");
 //[sparc]~^ ERROR -v8plus,-v9
 
-// FIXME: sparc_cpu_v9 should be in "-v8plus,+v9" group (fixed in LLVM 20)
 #[cfg(all(target_feature = "v8plus", target_feature = "v9"))]
 compile_error!("+v8plus,+v9");
-//[sparcv8plus,sparc_cpu_v9_feature_v8plus,sparc_cpu_v9]~^ ERROR +v8plus,+v9
+//[sparcv8plus,sparc_cpu_v9_feature_v8plus]~^ ERROR +v8plus,+v9
 
 // FIXME: should be rejected
 #[cfg(all(target_feature = "v8plus", not(target_feature = "v9")))]
@@ -41,3 +40,4 @@ compile_error!("+v8plus,-v9 (FIXME)");
 
 #[cfg(all(not(target_feature = "v8plus"), target_feature = "v9"))]
 compile_error!("-v8plus,+v9");
+//[sparc_cpu_v9]~^ ERROR -v8plus,+v9
diff --git a/tests/ui/abi/sparcv8plus.sparc_cpu_v9.stderr b/tests/ui/abi/sparcv8plus.sparc_cpu_v9.stderr
index 5e1e1fa5c798f..00fd7ef4ea8fb 100644
--- a/tests/ui/abi/sparcv8plus.sparc_cpu_v9.stderr
+++ b/tests/ui/abi/sparcv8plus.sparc_cpu_v9.stderr
@@ -1,7 +1,7 @@
-error: +v8plus,+v9
-  --> $DIR/sparcv8plus.rs:34:1
+error: -v8plus,+v9
+  --> $DIR/sparcv8plus.rs:42:1
    |
-LL | compile_error!("+v8plus,+v9");
+LL | compile_error!("-v8plus,+v9");
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: aborting due to 1 previous error
diff --git a/tests/ui/abi/sparcv8plus.sparc_cpu_v9_feature_v8plus.stderr b/tests/ui/abi/sparcv8plus.sparc_cpu_v9_feature_v8plus.stderr
index 5e1e1fa5c798f..a3c74e67f8f11 100644
--- a/tests/ui/abi/sparcv8plus.sparc_cpu_v9_feature_v8plus.stderr
+++ b/tests/ui/abi/sparcv8plus.sparc_cpu_v9_feature_v8plus.stderr
@@ -1,5 +1,5 @@
 error: +v8plus,+v9
-  --> $DIR/sparcv8plus.rs:34:1
+  --> $DIR/sparcv8plus.rs:33:1
    |
 LL | compile_error!("+v8plus,+v9");
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/tests/ui/abi/sparcv8plus.sparc_feature_v8plus.stderr b/tests/ui/abi/sparcv8plus.sparc_feature_v8plus.stderr
index 8a5375a46bc05..84f560d158ca9 100644
--- a/tests/ui/abi/sparcv8plus.sparc_feature_v8plus.stderr
+++ b/tests/ui/abi/sparcv8plus.sparc_feature_v8plus.stderr
@@ -1,5 +1,5 @@
 error: +v8plus,-v9 (FIXME)
-  --> $DIR/sparcv8plus.rs:39:1
+  --> $DIR/sparcv8plus.rs:38:1
    |
 LL | compile_error!("+v8plus,-v9 (FIXME)");
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/tests/ui/abi/sparcv8plus.sparcv8plus.stderr b/tests/ui/abi/sparcv8plus.sparcv8plus.stderr
index 5e1e1fa5c798f..a3c74e67f8f11 100644
--- a/tests/ui/abi/sparcv8plus.sparcv8plus.stderr
+++ b/tests/ui/abi/sparcv8plus.sparcv8plus.stderr
@@ -1,5 +1,5 @@
 error: +v8plus,+v9
-  --> $DIR/sparcv8plus.rs:34:1
+  --> $DIR/sparcv8plus.rs:33:1
    |
 LL | compile_error!("+v8plus,+v9");
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

From 2718710d4a505019c46ccc7db42d890f230de25e Mon Sep 17 00:00:00 2001
From: Nikita Popov <npopov@redhat.com>
Date: Mon, 20 Jan 2025 12:08:27 +0100
Subject: [PATCH 12/17] Fix x86_64-bigint-helpers test on LLVM 20

LLVM 20 choses a different unroll factor for the loop.
---
 tests/assembly/x86_64-bigint-helpers.rs | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/tests/assembly/x86_64-bigint-helpers.rs b/tests/assembly/x86_64-bigint-helpers.rs
index 198e554353909..3ad253a2bd0fe 100644
--- a/tests/assembly/x86_64-bigint-helpers.rs
+++ b/tests/assembly/x86_64-bigint-helpers.rs
@@ -2,6 +2,9 @@
 //@ assembly-output: emit-asm
 //@ compile-flags: --crate-type=lib -O -C target-cpu=x86-64-v4
 //@ compile-flags: -C llvm-args=-x86-asm-syntax=intel
+//@ revisions: llvm-pre-20 llvm-20
+//@ [llvm-20] min-llvm-version: 20
+//@ [llvm-pre-20] max-llvm-major-version: 19
 
 #![no_std]
 #![feature(bigint_helper_methods)]
@@ -20,12 +23,16 @@ pub unsafe extern "sysv64" fn bigint_chain_carrying_add(
     n: usize,
     mut carry: bool,
 ) -> bool {
-    // CHECK: mov [[TEMP:r..]], qword ptr [rsi + 8*[[IND:r..]] + 8]
-    // CHECK: adc [[TEMP]], qword ptr [rdx + 8*[[IND]] + 8]
-    // CHECK: mov qword ptr [rdi + 8*[[IND]] + 8], [[TEMP]]
-    // CHECK: mov [[TEMP]], qword ptr [rsi + 8*[[IND]] + 16]
-    // CHECK: adc [[TEMP]], qword ptr [rdx + 8*[[IND]] + 16]
-    // CHECK: mov qword ptr [rdi + 8*[[IND]] + 16], [[TEMP]]
+    // llvm-pre-20: mov [[TEMP:r..]], qword ptr [rsi + 8*[[IND:r..]] + 8]
+    // llvm-pre-20: adc [[TEMP]], qword ptr [rdx + 8*[[IND]] + 8]
+    // llvm-pre-20: mov qword ptr [rdi + 8*[[IND]] + 8], [[TEMP]]
+    // llvm-pre-20: mov [[TEMP]], qword ptr [rsi + 8*[[IND]] + 16]
+    // llvm-pre-20: adc [[TEMP]], qword ptr [rdx + 8*[[IND]] + 16]
+    // llvm-pre-20: mov qword ptr [rdi + 8*[[IND]] + 16], [[TEMP]]
+    // llvm-20: adc [[TEMP:r..]], qword ptr [rdx + 8*[[IND:r..]]]
+    // llvm-20: mov qword ptr [rdi + 8*[[IND]]], [[TEMP]]
+    // llvm-20: mov [[TEMP]], qword ptr [rsi + 8*[[IND]] + 8]
+    // llvm-20: adc [[TEMP]], qword ptr [rdx + 8*[[IND]] + 8]
     for i in 0..n {
         (*dest.add(i), carry) = u64::carrying_add(*src1.add(i), *src2.add(i), carry);
     }

From dd52bfc76e9d1136ba90c5aff1af22b0d5ca2631 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Esteban=20K=C3=BCber?= <esteban@kuber.com.ar>
Date: Mon, 18 Nov 2024 03:42:16 +0000
Subject: [PATCH 13/17] Reword "crate not found" resolve message

```
error[E0432]: unresolved import `some_novel_crate`
 --> file.rs:1:5
  |
1 | use some_novel_crate::Type;
  |     ^^^^^^^^^^^^^^^^ use of unresolved module or unlinked crate `some_novel_crate`
```

On resolve errors where there might be a missing crate, mention `cargo add foo`:

```
error[E0433]: failed to resolve: use of unresolved module or unlinked crate `nope`
  --> $DIR/conflicting-impl-with-err.rs:4:11
   |
LL | impl From<nope::Thing> for Error {
   |           ^^^^ use of unresolved module or unlinked crate `nope`
   |
   = help: if you wanted to use a crate named `nope`, use `cargo add nope` to add it to your `Cargo.toml`
```
---
 .../src/error_codes/E0433.md                  |  2 +-
 compiler/rustc_resolve/src/diagnostics.rs     | 36 +++++++++++--
 src/tools/miri/tests/fail/rustc-error2.rs     |  2 +-
 src/tools/miri/tests/fail/rustc-error2.stderr |  6 ++-
 .../ice-unresolved-import-100241.stderr       |  4 +-
 .../unresolved-import-recovery.stderr         |  6 +--
 tests/rustdoc-ui/issues/issue-61732.rs        |  2 +-
 tests/rustdoc-ui/issues/issue-61732.stderr    |  6 +--
 .../attributes/check-builtin-attr-ice.stderr  | 12 ++---
 tests/ui/attributes/check-cfg_attr-ice.stderr | 52 +++++++++----------
 .../field-attributes-vis-unresolved.stderr    | 12 ++---
 .../conflicting-impl-with-err.stderr          | 12 +++--
 tests/ui/delegation/bad-resolve.rs            |  2 +-
 tests/ui/delegation/bad-resolve.stderr        |  6 ++-
 tests/ui/delegation/glob-bad-path.rs          |  2 +-
 tests/ui/delegation/glob-bad-path.stderr      |  4 +-
 tests/ui/error-codes/E0432.stderr             |  4 +-
 tests/ui/extern-flag/multiple-opts.stderr     |  6 ++-
 tests/ui/extern-flag/noprelude.stderr         |  6 ++-
 tests/ui/foreign/stashed-issue-121451.rs      |  2 +-
 tests/ui/foreign/stashed-issue-121451.stderr  |  6 ++-
 .../extern-prelude-from-opaque-fail-2018.rs   |  4 +-
 ...xtern-prelude-from-opaque-fail-2018.stderr | 10 ++--
 .../extern-prelude-from-opaque-fail.rs        |  4 +-
 .../extern-prelude-from-opaque-fail.stderr    | 10 ++--
 tests/ui/impl-trait/issue-72911.stderr        | 12 +++--
 .../impl-trait/stashed-diag-issue-121504.rs   |  2 +-
 .../stashed-diag-issue-121504.stderr          |  6 ++-
 .../extern-prelude-extern-crate-fail.rs       |  2 +-
 .../extern-prelude-extern-crate-fail.stderr   |  4 +-
 .../imports/import-from-missing-star-2.stderr |  4 +-
 .../imports/import-from-missing-star-3.stderr |  8 +--
 .../imports/import-from-missing-star.stderr   |  4 +-
 tests/ui/imports/import3.stderr               |  4 +-
 tests/ui/imports/issue-109343.stderr          |  4 +-
 tests/ui/imports/issue-1697.rs                |  4 +-
 tests/ui/imports/issue-1697.stderr            |  4 +-
 tests/ui/imports/issue-33464.stderr           | 12 ++---
 tests/ui/imports/issue-36881.stderr           |  4 +-
 tests/ui/imports/issue-37887.stderr           |  4 +-
 tests/ui/imports/issue-53269.stderr           |  4 +-
 tests/ui/imports/issue-55457.stderr           |  4 +-
 tests/ui/imports/issue-81413.stderr           |  4 +-
 tests/ui/imports/tool-mod-child.rs            |  4 +-
 tests/ui/imports/tool-mod-child.stderr        | 20 +++----
 .../ui/imports/unresolved-imports-used.stderr | 16 +++---
 tests/ui/issues/issue-33293.rs                |  2 +-
 tests/ui/issues/issue-33293.stderr            |  6 ++-
 .../keyword-extern-as-identifier-use.stderr   |  4 +-
 .../ui/macros/builtin-prelude-no-accidents.rs |  6 +--
 .../builtin-prelude-no-accidents.stderr       | 15 +++---
 tests/ui/macros/macro-inner-attributes.rs     |  2 +-
 tests/ui/macros/macro-inner-attributes.stderr |  4 +-
 .../macros/macro_path_as_generic_bound.stderr |  6 ++-
 .../ui/macros/meta-item-absolute-path.stderr  |  8 +--
 tests/ui/mir/issue-121103.rs                  |  4 +-
 tests/ui/mir/issue-121103.stderr              | 12 +++--
 .../mod_file_disambig.rs                      |  2 +-
 .../mod_file_disambig.stderr                  |  6 ++-
 ...onst-param-decl-on-type-instead-of-impl.rs |  2 +-
 ...-param-decl-on-type-instead-of-impl.stderr |  6 ++-
 tests/ui/parser/dyn-trait-compatibility.rs    |  2 +-
 .../ui/parser/dyn-trait-compatibility.stderr  |  6 ++-
 tests/ui/parser/mod_file_not_exist.rs         |  3 +-
 tests/ui/parser/mod_file_not_exist.stderr     |  6 ++-
 tests/ui/parser/mod_file_not_exist_windows.rs |  3 +-
 .../parser/mod_file_not_exist_windows.stderr  |  6 ++-
 tests/ui/privacy/restricted/test.rs           |  2 +-
 tests/ui/privacy/restricted/test.stderr       |  6 +--
 tests/ui/resolve/112590-2.stderr              | 16 +++---
 tests/ui/resolve/bad-module.rs                |  4 +-
 tests/ui/resolve/bad-module.stderr            | 12 +++--
 tests/ui/resolve/editions-crate-root-2015.rs  |  4 +-
 .../resolve/editions-crate-root-2015.stderr   | 12 ++---
 .../ui/resolve/export-fully-qualified-2018.rs |  2 +-
 .../export-fully-qualified-2018.stderr        |  6 ++-
 tests/ui/resolve/export-fully-qualified.rs    |  2 +-
 .../ui/resolve/export-fully-qualified.stderr  |  6 ++-
 tests/ui/resolve/extern-prelude-fail.stderr   | 10 ++--
 tests/ui/resolve/issue-101749-2.rs            |  2 +-
 tests/ui/resolve/issue-101749-2.stderr        |  6 ++-
 tests/ui/resolve/issue-101749.fixed           |  2 +-
 tests/ui/resolve/issue-101749.rs              |  2 +-
 tests/ui/resolve/issue-101749.stderr          |  5 +-
 tests/ui/resolve/issue-82865.rs               |  2 +-
 tests/ui/resolve/issue-82865.stderr           |  6 +--
 .../ui/resolve/resolve-bad-visibility.stderr  | 12 ++---
 .../typo-suggestion-mistyped-in-path.rs       |  4 +-
 .../typo-suggestion-mistyped-in-path.stderr   |  4 +-
 .../non-existent-1.stderr                     |  4 +-
 .../unresolved-asterisk-imports.stderr        |  4 +-
 tests/ui/suggestions/crate-or-module-typo.rs  |  4 +-
 .../suggestions/crate-or-module-typo.stderr   | 10 ++--
 .../issue-112590-suggest-import.rs            |  6 +--
 .../issue-112590-suggest-import.stderr        | 15 +++---
 .../ui/suggestions/undeclared-module-alloc.rs |  2 +-
 .../undeclared-module-alloc.stderr            |  4 +-
 tests/ui/tool-attributes/unknown-tool-name.rs |  2 +-
 .../tool-attributes/unknown-tool-name.stderr  |  4 +-
 tests/ui/typeck/issue-120856.rs               |  4 +-
 tests/ui/typeck/issue-120856.stderr           | 12 +++--
 ...-sugg-unresolved-expr.cargo-invoked.stderr | 11 ++++
 ...hod-sugg-unresolved-expr.only-rustc.stderr | 11 ++++
 .../path-to-method-sugg-unresolved-expr.rs    |  8 ++-
 ...path-to-method-sugg-unresolved-expr.stderr |  9 ----
 .../unresolved-asterisk-imports.stderr        |  4 +-
 tests/ui/unresolved/unresolved-import.rs      |  4 +-
 tests/ui/unresolved/unresolved-import.stderr  |  4 +-
 108 files changed, 414 insertions(+), 294 deletions(-)
 create mode 100644 tests/ui/typeck/path-to-method-sugg-unresolved-expr.cargo-invoked.stderr
 create mode 100644 tests/ui/typeck/path-to-method-sugg-unresolved-expr.only-rustc.stderr
 delete mode 100644 tests/ui/typeck/path-to-method-sugg-unresolved-expr.stderr

diff --git a/compiler/rustc_error_codes/src/error_codes/E0433.md b/compiler/rustc_error_codes/src/error_codes/E0433.md
index 5a64c13c9af51..36e4b66e8dcdf 100644
--- a/compiler/rustc_error_codes/src/error_codes/E0433.md
+++ b/compiler/rustc_error_codes/src/error_codes/E0433.md
@@ -19,7 +19,7 @@ If you've expected to use a crate name:
 
 ```compile_fail
 use ferris_wheel::BigO;
-// error: failed to resolve: use of undeclared crate or module `ferris_wheel`
+// error: failed to resolve: use of undeclared module or unlinked crate
 ```
 
 Make sure the crate has been added as a dependency in `Cargo.toml`.
diff --git a/compiler/rustc_resolve/src/diagnostics.rs b/compiler/rustc_resolve/src/diagnostics.rs
index ba217b7c88a8e..6f32918e057f8 100644
--- a/compiler/rustc_resolve/src/diagnostics.rs
+++ b/compiler/rustc_resolve/src/diagnostics.rs
@@ -24,6 +24,7 @@ use rustc_session::lint::builtin::{
     MACRO_EXPANDED_MACRO_EXPORTS_ACCESSED_BY_ABSOLUTE_PATHS,
 };
 use rustc_session::lint::{AmbiguityErrorDiag, BuiltinLintDiag};
+use rustc_session::utils::was_invoked_from_cargo;
 use rustc_span::edit_distance::find_best_match_for_name;
 use rustc_span::edition::Edition;
 use rustc_span::hygiene::MacroKind;
@@ -809,7 +810,6 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                     }
                     err.multipart_suggestion(msg, suggestions, applicability);
                 }
-
                 if let Some(ModuleOrUniformRoot::Module(module)) = module
                     && let Some(module) = module.opt_def_id()
                     && let Some(segment) = segment
@@ -2044,13 +2044,23 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                 (format!("`_` is not a valid crate or module name"), None)
             } else if self.tcx.sess.is_rust_2015() {
                 (
-                    format!("you might be missing crate `{ident}`"),
+                    format!("use of unresolved module or unlinked crate `{ident}`"),
                     Some((
                         vec![(
                             self.current_crate_outer_attr_insert_span,
                             format!("extern crate {ident};\n"),
                         )],
-                        format!("consider importing the `{ident}` crate"),
+                        if was_invoked_from_cargo() {
+                            format!(
+                                "if you wanted to use a crate named `{ident}`, use `cargo add {ident}` \
+                             to add it to your `Cargo.toml` and import it in your code",
+                            )
+                        } else {
+                            format!(
+                                "you might be missing a crate named `{ident}`, add it to your \
+                                 project and import it in your code",
+                            )
+                        },
                         Applicability::MaybeIncorrect,
                     )),
                 )
@@ -2229,7 +2239,25 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                 let descr = binding.res().descr();
                 (format!("{descr} `{ident}` is not a crate or module"), suggestion)
             } else {
-                (format!("use of undeclared crate or module `{ident}`"), suggestion)
+                let suggestion = if suggestion.is_some() {
+                    suggestion
+                } else if was_invoked_from_cargo() {
+                    Some((
+                        vec![],
+                        format!(
+                            "if you wanted to use a crate named `{ident}`, use `cargo add {ident}` \
+                             to add it to your `Cargo.toml`",
+                        ),
+                        Applicability::MaybeIncorrect,
+                    ))
+                } else {
+                    Some((
+                        vec![],
+                        format!("you might be missing a crate named `{ident}`",),
+                        Applicability::MaybeIncorrect,
+                    ))
+                };
+                (format!("use of unresolved module or unlinked crate `{ident}`"), suggestion)
             }
         }
     }
diff --git a/src/tools/miri/tests/fail/rustc-error2.rs b/src/tools/miri/tests/fail/rustc-error2.rs
index fd2c53933856d..ec42fd17e8927 100644
--- a/src/tools/miri/tests/fail/rustc-error2.rs
+++ b/src/tools/miri/tests/fail/rustc-error2.rs
@@ -4,7 +4,7 @@ struct Struct<T>(T);
 impl<T> std::ops::Deref for Struct<T> {
     type Target = dyn Fn(T);
     fn deref(&self) -> &assert_mem_uninitialized_valid::Target {
-        //~^ERROR: undeclared crate or module
+        //~^ERROR: use of unresolved module or unlinked crate
         unimplemented!()
     }
 }
diff --git a/src/tools/miri/tests/fail/rustc-error2.stderr b/src/tools/miri/tests/fail/rustc-error2.stderr
index cfbf305d3bbfe..62e3f392ea9df 100644
--- a/src/tools/miri/tests/fail/rustc-error2.stderr
+++ b/src/tools/miri/tests/fail/rustc-error2.stderr
@@ -1,8 +1,10 @@
-error[E0433]: failed to resolve: use of undeclared crate or module `assert_mem_uninitialized_valid`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `assert_mem_uninitialized_valid`
   --> tests/fail/rustc-error2.rs:LL:CC
    |
 LL |     fn deref(&self) -> &assert_mem_uninitialized_valid::Target {
-   |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ use of undeclared crate or module `assert_mem_uninitialized_valid`
+   |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ use of unresolved module or unlinked crate `assert_mem_uninitialized_valid`
+   |
+   = help: you might be missing a crate named `assert_mem_uninitialized_valid`
 
 error: aborting due to 1 previous error
 
diff --git a/tests/rustdoc-ui/ice-unresolved-import-100241.stderr b/tests/rustdoc-ui/ice-unresolved-import-100241.stderr
index 2eebedba9a5ee..a82847d381c5c 100644
--- a/tests/rustdoc-ui/ice-unresolved-import-100241.stderr
+++ b/tests/rustdoc-ui/ice-unresolved-import-100241.stderr
@@ -2,9 +2,9 @@ error[E0432]: unresolved import `inner`
   --> $DIR/ice-unresolved-import-100241.rs:9:13
    |
 LL |     pub use inner::S;
-   |             ^^^^^ you might be missing crate `inner`
+   |             ^^^^^ use of unresolved module or unlinked crate `inner`
    |
-help: consider importing the `inner` crate
+help: you might be missing a crate named `inner`, add it to your project and import it in your code
    |
 LL + extern crate inner;
    |
diff --git a/tests/rustdoc-ui/intra-doc/unresolved-import-recovery.stderr b/tests/rustdoc-ui/intra-doc/unresolved-import-recovery.stderr
index e68943192130d..dcdd230c25a1c 100644
--- a/tests/rustdoc-ui/intra-doc/unresolved-import-recovery.stderr
+++ b/tests/rustdoc-ui/intra-doc/unresolved-import-recovery.stderr
@@ -1,10 +1,10 @@
-error[E0433]: failed to resolve: you might be missing crate `unresolved_crate`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `unresolved_crate`
   --> $DIR/unresolved-import-recovery.rs:3:5
    |
 LL | use unresolved_crate::module::Name;
-   |     ^^^^^^^^^^^^^^^^ you might be missing crate `unresolved_crate`
+   |     ^^^^^^^^^^^^^^^^ use of unresolved module or unlinked crate `unresolved_crate`
    |
-help: consider importing the `unresolved_crate` crate
+help: you might be missing a crate named `unresolved_crate`, add it to your project and import it in your code
    |
 LL + extern crate unresolved_crate;
    |
diff --git a/tests/rustdoc-ui/issues/issue-61732.rs b/tests/rustdoc-ui/issues/issue-61732.rs
index 3969ab92c32ee..d5d9ad5e4637d 100644
--- a/tests/rustdoc-ui/issues/issue-61732.rs
+++ b/tests/rustdoc-ui/issues/issue-61732.rs
@@ -1,4 +1,4 @@
 // This previously triggered an ICE.
 
 pub(in crate::r#mod) fn main() {}
-//~^ ERROR failed to resolve: you might be missing crate `r#mod`
+//~^ ERROR failed to resolve: use of unresolved module or unlinked crate `r#mod`
diff --git a/tests/rustdoc-ui/issues/issue-61732.stderr b/tests/rustdoc-ui/issues/issue-61732.stderr
index 0aa7d558c307d..c4e6997ab74d4 100644
--- a/tests/rustdoc-ui/issues/issue-61732.stderr
+++ b/tests/rustdoc-ui/issues/issue-61732.stderr
@@ -1,10 +1,10 @@
-error[E0433]: failed to resolve: you might be missing crate `r#mod`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `r#mod`
   --> $DIR/issue-61732.rs:3:15
    |
 LL | pub(in crate::r#mod) fn main() {}
-   |               ^^^^^ you might be missing crate `r#mod`
+   |               ^^^^^ use of unresolved module or unlinked crate `r#mod`
    |
-help: consider importing the `r#mod` crate
+help: you might be missing a crate named `r#mod`, add it to your project and import it in your code
    |
 LL + extern crate r#mod;
    |
diff --git a/tests/ui/attributes/check-builtin-attr-ice.stderr b/tests/ui/attributes/check-builtin-attr-ice.stderr
index 5a27da565a857..06a4769b2b421 100644
--- a/tests/ui/attributes/check-builtin-attr-ice.stderr
+++ b/tests/ui/attributes/check-builtin-attr-ice.stderr
@@ -1,20 +1,20 @@
-error[E0433]: failed to resolve: use of undeclared crate or module `should_panic`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `should_panic`
   --> $DIR/check-builtin-attr-ice.rs:43:7
    |
 LL |     #[should_panic::skip]
-   |       ^^^^^^^^^^^^ use of undeclared crate or module `should_panic`
+   |       ^^^^^^^^^^^^ use of unresolved module or unlinked crate `should_panic`
 
-error[E0433]: failed to resolve: use of undeclared crate or module `should_panic`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `should_panic`
   --> $DIR/check-builtin-attr-ice.rs:47:7
    |
 LL |     #[should_panic::a::b::c]
-   |       ^^^^^^^^^^^^ use of undeclared crate or module `should_panic`
+   |       ^^^^^^^^^^^^ use of unresolved module or unlinked crate `should_panic`
 
-error[E0433]: failed to resolve: use of undeclared crate or module `deny`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `deny`
   --> $DIR/check-builtin-attr-ice.rs:55:7
    |
 LL |     #[deny::skip]
-   |       ^^^^ use of undeclared crate or module `deny`
+   |       ^^^^ use of unresolved module or unlinked crate `deny`
 
 error: aborting due to 3 previous errors
 
diff --git a/tests/ui/attributes/check-cfg_attr-ice.stderr b/tests/ui/attributes/check-cfg_attr-ice.stderr
index dbdf32597f7b2..bed3150bdc2f3 100644
--- a/tests/ui/attributes/check-cfg_attr-ice.stderr
+++ b/tests/ui/attributes/check-cfg_attr-ice.stderr
@@ -17,83 +17,83 @@ LL |         #[cfg_attr::no_such_thing]
    = help: add `#![feature(stmt_expr_attributes)]` to the crate attributes to enable
    = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
 
-error[E0433]: failed to resolve: use of undeclared crate or module `cfg_attr`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `cfg_attr`
   --> $DIR/check-cfg_attr-ice.rs:52:3
    |
 LL | #[cfg_attr::no_such_thing]
-   |   ^^^^^^^^ use of undeclared crate or module `cfg_attr`
+   |   ^^^^^^^^ use of unresolved module or unlinked crate `cfg_attr`
 
-error[E0433]: failed to resolve: use of undeclared crate or module `cfg_attr`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `cfg_attr`
   --> $DIR/check-cfg_attr-ice.rs:55:7
    |
 LL |     #[cfg_attr::no_such_thing]
-   |       ^^^^^^^^ use of undeclared crate or module `cfg_attr`
+   |       ^^^^^^^^ use of unresolved module or unlinked crate `cfg_attr`
 
-error[E0433]: failed to resolve: use of undeclared crate or module `cfg_attr`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `cfg_attr`
   --> $DIR/check-cfg_attr-ice.rs:57:17
    |
 LL |     GiveYouUp(#[cfg_attr::no_such_thing] u8),
-   |                 ^^^^^^^^ use of undeclared crate or module `cfg_attr`
+   |                 ^^^^^^^^ use of unresolved module or unlinked crate `cfg_attr`
 
-error[E0433]: failed to resolve: use of undeclared crate or module `cfg_attr`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `cfg_attr`
   --> $DIR/check-cfg_attr-ice.rs:64:11
    |
 LL |         #[cfg_attr::no_such_thing]
-   |           ^^^^^^^^ use of undeclared crate or module `cfg_attr`
+   |           ^^^^^^^^ use of unresolved module or unlinked crate `cfg_attr`
 
-error[E0433]: failed to resolve: use of undeclared crate or module `cfg_attr`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `cfg_attr`
   --> $DIR/check-cfg_attr-ice.rs:41:7
    |
 LL |     #[cfg_attr::no_such_thing]
-   |       ^^^^^^^^ use of undeclared crate or module `cfg_attr`
+   |       ^^^^^^^^ use of unresolved module or unlinked crate `cfg_attr`
 
-error[E0433]: failed to resolve: use of undeclared crate or module `cfg_attr`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `cfg_attr`
   --> $DIR/check-cfg_attr-ice.rs:43:15
    |
 LL |     fn from(#[cfg_attr::no_such_thing] any_other_guy: AnyOtherGuy) -> This {
-   |               ^^^^^^^^ use of undeclared crate or module `cfg_attr`
+   |               ^^^^^^^^ use of unresolved module or unlinked crate `cfg_attr`
 
-error[E0433]: failed to resolve: use of undeclared crate or module `cfg_attr`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `cfg_attr`
   --> $DIR/check-cfg_attr-ice.rs:45:11
    |
 LL |         #[cfg_attr::no_such_thing]
-   |           ^^^^^^^^ use of undeclared crate or module `cfg_attr`
+   |           ^^^^^^^^ use of unresolved module or unlinked crate `cfg_attr`
 
-error[E0433]: failed to resolve: use of undeclared crate or module `cfg_attr`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `cfg_attr`
   --> $DIR/check-cfg_attr-ice.rs:32:3
    |
 LL | #[cfg_attr::no_such_thing]
-   |   ^^^^^^^^ use of undeclared crate or module `cfg_attr`
+   |   ^^^^^^^^ use of unresolved module or unlinked crate `cfg_attr`
 
-error[E0433]: failed to resolve: use of undeclared crate or module `cfg_attr`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `cfg_attr`
   --> $DIR/check-cfg_attr-ice.rs:24:3
    |
 LL | #[cfg_attr::no_such_thing]
-   |   ^^^^^^^^ use of undeclared crate or module `cfg_attr`
+   |   ^^^^^^^^ use of unresolved module or unlinked crate `cfg_attr`
 
-error[E0433]: failed to resolve: use of undeclared crate or module `cfg_attr`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `cfg_attr`
   --> $DIR/check-cfg_attr-ice.rs:27:7
    |
 LL |     #[cfg_attr::no_such_thing]
-   |       ^^^^^^^^ use of undeclared crate or module `cfg_attr`
+   |       ^^^^^^^^ use of unresolved module or unlinked crate `cfg_attr`
 
-error[E0433]: failed to resolve: use of undeclared crate or module `cfg_attr`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `cfg_attr`
   --> $DIR/check-cfg_attr-ice.rs:16:3
    |
 LL | #[cfg_attr::no_such_thing]
-   |   ^^^^^^^^ use of undeclared crate or module `cfg_attr`
+   |   ^^^^^^^^ use of unresolved module or unlinked crate `cfg_attr`
 
-error[E0433]: failed to resolve: use of undeclared crate or module `cfg_attr`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `cfg_attr`
   --> $DIR/check-cfg_attr-ice.rs:19:7
    |
 LL |     #[cfg_attr::no_such_thing]
-   |       ^^^^^^^^ use of undeclared crate or module `cfg_attr`
+   |       ^^^^^^^^ use of unresolved module or unlinked crate `cfg_attr`
 
-error[E0433]: failed to resolve: use of undeclared crate or module `cfg_attr`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `cfg_attr`
   --> $DIR/check-cfg_attr-ice.rs:12:3
    |
 LL | #[cfg_attr::no_such_thing]
-   |   ^^^^^^^^ use of undeclared crate or module `cfg_attr`
+   |   ^^^^^^^^ use of unresolved module or unlinked crate `cfg_attr`
 
 error: aborting due to 15 previous errors
 
diff --git a/tests/ui/attributes/field-attributes-vis-unresolved.stderr b/tests/ui/attributes/field-attributes-vis-unresolved.stderr
index f8610c08b0220..d689b76eaf8b0 100644
--- a/tests/ui/attributes/field-attributes-vis-unresolved.stderr
+++ b/tests/ui/attributes/field-attributes-vis-unresolved.stderr
@@ -1,21 +1,21 @@
-error[E0433]: failed to resolve: you might be missing crate `nonexistent`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `nonexistent`
   --> $DIR/field-attributes-vis-unresolved.rs:17:12
    |
 LL |     pub(in nonexistent) field: u8
-   |            ^^^^^^^^^^^ you might be missing crate `nonexistent`
+   |            ^^^^^^^^^^^ use of unresolved module or unlinked crate `nonexistent`
    |
-help: consider importing the `nonexistent` crate
+help: you might be missing a crate named `nonexistent`, add it to your project and import it in your code
    |
 LL + extern crate nonexistent;
    |
 
-error[E0433]: failed to resolve: you might be missing crate `nonexistent`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `nonexistent`
   --> $DIR/field-attributes-vis-unresolved.rs:22:12
    |
 LL |     pub(in nonexistent) u8
-   |            ^^^^^^^^^^^ you might be missing crate `nonexistent`
+   |            ^^^^^^^^^^^ use of unresolved module or unlinked crate `nonexistent`
    |
-help: consider importing the `nonexistent` crate
+help: you might be missing a crate named `nonexistent`, add it to your project and import it in your code
    |
 LL + extern crate nonexistent;
    |
diff --git a/tests/ui/coherence/conflicting-impl-with-err.stderr b/tests/ui/coherence/conflicting-impl-with-err.stderr
index 3009b452dc7a0..75a201797b551 100644
--- a/tests/ui/coherence/conflicting-impl-with-err.stderr
+++ b/tests/ui/coherence/conflicting-impl-with-err.stderr
@@ -1,14 +1,18 @@
-error[E0433]: failed to resolve: use of undeclared crate or module `nope`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `nope`
   --> $DIR/conflicting-impl-with-err.rs:4:11
    |
 LL | impl From<nope::Thing> for Error {
-   |           ^^^^ use of undeclared crate or module `nope`
+   |           ^^^^ use of unresolved module or unlinked crate `nope`
+   |
+   = help: you might be missing a crate named `nope`
 
-error[E0433]: failed to resolve: use of undeclared crate or module `nope`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `nope`
   --> $DIR/conflicting-impl-with-err.rs:5:16
    |
 LL |     fn from(_: nope::Thing) -> Self {
-   |                ^^^^ use of undeclared crate or module `nope`
+   |                ^^^^ use of unresolved module or unlinked crate `nope`
+   |
+   = help: you might be missing a crate named `nope`
 
 error: aborting due to 2 previous errors
 
diff --git a/tests/ui/delegation/bad-resolve.rs b/tests/ui/delegation/bad-resolve.rs
index f15e6aa81afb0..861f2b15da205 100644
--- a/tests/ui/delegation/bad-resolve.rs
+++ b/tests/ui/delegation/bad-resolve.rs
@@ -40,7 +40,7 @@ impl Trait for S {
 }
 
 mod prefix {}
-reuse unresolved_prefix::{a, b, c}; //~ ERROR use of undeclared crate or module `unresolved_prefix`
+reuse unresolved_prefix::{a, b, c}; //~ ERROR use of unresolved module or unlinked crate
 reuse prefix::{self, super, crate}; //~ ERROR `crate` in paths can only be used in start position
 
 fn main() {}
diff --git a/tests/ui/delegation/bad-resolve.stderr b/tests/ui/delegation/bad-resolve.stderr
index 32d2f3b26cb03..966387e1d6164 100644
--- a/tests/ui/delegation/bad-resolve.stderr
+++ b/tests/ui/delegation/bad-resolve.stderr
@@ -81,11 +81,13 @@ LL |     type Type;
 LL | impl Trait for S {
    | ^^^^^^^^^^^^^^^^ missing `Type` in implementation
 
-error[E0433]: failed to resolve: use of undeclared crate or module `unresolved_prefix`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `unresolved_prefix`
   --> $DIR/bad-resolve.rs:43:7
    |
 LL | reuse unresolved_prefix::{a, b, c};
-   |       ^^^^^^^^^^^^^^^^^ use of undeclared crate or module `unresolved_prefix`
+   |       ^^^^^^^^^^^^^^^^^ use of unresolved module or unlinked crate `unresolved_prefix`
+   |
+   = help: you might be missing a crate named `unresolved_prefix`
 
 error[E0433]: failed to resolve: `crate` in paths can only be used in start position
   --> $DIR/bad-resolve.rs:44:29
diff --git a/tests/ui/delegation/glob-bad-path.rs b/tests/ui/delegation/glob-bad-path.rs
index 7bc4f0153a308..4ac9d68e8dd1c 100644
--- a/tests/ui/delegation/glob-bad-path.rs
+++ b/tests/ui/delegation/glob-bad-path.rs
@@ -5,7 +5,7 @@ trait Trait {}
 struct S;
 
 impl Trait for u8 {
-    reuse unresolved::*; //~ ERROR failed to resolve: use of undeclared crate or module `unresolved`
+    reuse unresolved::*; //~ ERROR failed to resolve: use of unresolved module or unlinked crate `unresolved`
     reuse S::*; //~ ERROR expected trait, found struct `S`
 }
 
diff --git a/tests/ui/delegation/glob-bad-path.stderr b/tests/ui/delegation/glob-bad-path.stderr
index 0c06364b3f0ab..15d9ca4120332 100644
--- a/tests/ui/delegation/glob-bad-path.stderr
+++ b/tests/ui/delegation/glob-bad-path.stderr
@@ -4,11 +4,11 @@ error: expected trait, found struct `S`
 LL |     reuse S::*;
    |           ^ not a trait
 
-error[E0433]: failed to resolve: use of undeclared crate or module `unresolved`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `unresolved`
   --> $DIR/glob-bad-path.rs:8:11
    |
 LL |     reuse unresolved::*;
-   |           ^^^^^^^^^^ use of undeclared crate or module `unresolved`
+   |           ^^^^^^^^^^ use of unresolved module or unlinked crate `unresolved`
 
 error: aborting due to 2 previous errors
 
diff --git a/tests/ui/error-codes/E0432.stderr b/tests/ui/error-codes/E0432.stderr
index 36fefc95897d6..4ff8b40d1969d 100644
--- a/tests/ui/error-codes/E0432.stderr
+++ b/tests/ui/error-codes/E0432.stderr
@@ -2,9 +2,9 @@ error[E0432]: unresolved import `something`
   --> $DIR/E0432.rs:1:5
    |
 LL | use something::Foo;
-   |     ^^^^^^^^^ you might be missing crate `something`
+   |     ^^^^^^^^^ use of unresolved module or unlinked crate `something`
    |
-help: consider importing the `something` crate
+help: you might be missing a crate named `something`, add it to your project and import it in your code
    |
 LL + extern crate something;
    |
diff --git a/tests/ui/extern-flag/multiple-opts.stderr b/tests/ui/extern-flag/multiple-opts.stderr
index 0aaca5ee253e4..d0f38bad94c6e 100644
--- a/tests/ui/extern-flag/multiple-opts.stderr
+++ b/tests/ui/extern-flag/multiple-opts.stderr
@@ -1,8 +1,10 @@
-error[E0433]: failed to resolve: use of undeclared crate or module `somedep`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `somedep`
   --> $DIR/multiple-opts.rs:19:5
    |
 LL |     somedep::somefun();
-   |     ^^^^^^^ use of undeclared crate or module `somedep`
+   |     ^^^^^^^ use of unresolved module or unlinked crate `somedep`
+   |
+   = help: you might be missing a crate named `somedep`
 
 error: aborting due to 1 previous error
 
diff --git a/tests/ui/extern-flag/noprelude.stderr b/tests/ui/extern-flag/noprelude.stderr
index 23b9b2fd94b27..fbd84956f66dc 100644
--- a/tests/ui/extern-flag/noprelude.stderr
+++ b/tests/ui/extern-flag/noprelude.stderr
@@ -1,8 +1,10 @@
-error[E0433]: failed to resolve: use of undeclared crate or module `somedep`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `somedep`
   --> $DIR/noprelude.rs:6:5
    |
 LL |     somedep::somefun();
-   |     ^^^^^^^ use of undeclared crate or module `somedep`
+   |     ^^^^^^^ use of unresolved module or unlinked crate `somedep`
+   |
+   = help: you might be missing a crate named `somedep`
 
 error: aborting due to 1 previous error
 
diff --git a/tests/ui/foreign/stashed-issue-121451.rs b/tests/ui/foreign/stashed-issue-121451.rs
index 97a4af374758d..77a736739bfa0 100644
--- a/tests/ui/foreign/stashed-issue-121451.rs
+++ b/tests/ui/foreign/stashed-issue-121451.rs
@@ -1,4 +1,4 @@
 extern "C" fn _f() -> libc::uintptr_t {}
-//~^ ERROR failed to resolve: use of undeclared crate or module `libc`
+//~^ ERROR failed to resolve
 
 fn main() {}
diff --git a/tests/ui/foreign/stashed-issue-121451.stderr b/tests/ui/foreign/stashed-issue-121451.stderr
index 440d98d6f460d..31dd3b4fb5e8d 100644
--- a/tests/ui/foreign/stashed-issue-121451.stderr
+++ b/tests/ui/foreign/stashed-issue-121451.stderr
@@ -1,8 +1,10 @@
-error[E0433]: failed to resolve: use of undeclared crate or module `libc`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `libc`
   --> $DIR/stashed-issue-121451.rs:1:23
    |
 LL | extern "C" fn _f() -> libc::uintptr_t {}
-   |                       ^^^^ use of undeclared crate or module `libc`
+   |                       ^^^^ use of unresolved module or unlinked crate `libc`
+   |
+   = help: you might be missing a crate named `libc`
 
 error: aborting due to 1 previous error
 
diff --git a/tests/ui/hygiene/extern-prelude-from-opaque-fail-2018.rs b/tests/ui/hygiene/extern-prelude-from-opaque-fail-2018.rs
index aaf831d1983e4..71c33674b37fc 100644
--- a/tests/ui/hygiene/extern-prelude-from-opaque-fail-2018.rs
+++ b/tests/ui/hygiene/extern-prelude-from-opaque-fail-2018.rs
@@ -10,7 +10,7 @@ macro a() {
     mod u {
         // Late resolution.
         fn f() { my_core::mem::drop(0); }
-        //~^ ERROR failed to resolve: use of undeclared crate or module `my_core`
+        //~^ ERROR failed to resolve: use of unresolved module or unlinked crate `my_core`
     }
 }
 
@@ -23,7 +23,7 @@ mod v {
 mod u {
     // Late resolution.
     fn f() { my_core::mem::drop(0); }
-    //~^ ERROR failed to resolve: use of undeclared crate or module `my_core`
+    //~^ ERROR failed to resolve: use of unresolved module or unlinked crate `my_core`
 }
 
 fn main() {}
diff --git a/tests/ui/hygiene/extern-prelude-from-opaque-fail-2018.stderr b/tests/ui/hygiene/extern-prelude-from-opaque-fail-2018.stderr
index cc229764ad3fb..87ef07c27f5bd 100644
--- a/tests/ui/hygiene/extern-prelude-from-opaque-fail-2018.stderr
+++ b/tests/ui/hygiene/extern-prelude-from-opaque-fail-2018.stderr
@@ -15,25 +15,27 @@ LL | a!();
    |
    = note: this error originates in the macro `a` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error[E0433]: failed to resolve: use of undeclared crate or module `my_core`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `my_core`
   --> $DIR/extern-prelude-from-opaque-fail-2018.rs:12:18
    |
 LL |         fn f() { my_core::mem::drop(0); }
-   |                  ^^^^^^^ use of undeclared crate or module `my_core`
+   |                  ^^^^^^^ use of unresolved module or unlinked crate `my_core`
 ...
 LL | a!();
    | ---- in this macro invocation
    |
+   = help: you might be missing a crate named `my_core`
    = help: consider importing this module:
            std::mem
    = note: this error originates in the macro `a` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error[E0433]: failed to resolve: use of undeclared crate or module `my_core`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `my_core`
   --> $DIR/extern-prelude-from-opaque-fail-2018.rs:25:14
    |
 LL |     fn f() { my_core::mem::drop(0); }
-   |              ^^^^^^^ use of undeclared crate or module `my_core`
+   |              ^^^^^^^ use of unresolved module or unlinked crate `my_core`
    |
+   = help: you might be missing a crate named `my_core`
 help: consider importing this module
    |
 LL +     use std::mem;
diff --git a/tests/ui/hygiene/extern-prelude-from-opaque-fail.rs b/tests/ui/hygiene/extern-prelude-from-opaque-fail.rs
index be3102aeab07f..8265b73cc565b 100644
--- a/tests/ui/hygiene/extern-prelude-from-opaque-fail.rs
+++ b/tests/ui/hygiene/extern-prelude-from-opaque-fail.rs
@@ -10,7 +10,7 @@ macro a() {
     mod u {
         // Late resolution.
         fn f() { my_core::mem::drop(0); }
-        //~^ ERROR failed to resolve: use of undeclared crate or module `my_core`
+        //~^ ERROR failed to resolve: use of unresolved module or unlinked crate `my_core`
     }
 }
 
@@ -23,7 +23,7 @@ mod v {
 mod u {
     // Late resolution.
     fn f() { my_core::mem::drop(0); }
-    //~^ ERROR failed to resolve: use of undeclared crate or module `my_core`
+    //~^ ERROR failed to resolve: use of unresolved module or unlinked crate `my_core`
 }
 
 fn main() {}
diff --git a/tests/ui/hygiene/extern-prelude-from-opaque-fail.stderr b/tests/ui/hygiene/extern-prelude-from-opaque-fail.stderr
index 13b2827ef39b8..d36bc9130953e 100644
--- a/tests/ui/hygiene/extern-prelude-from-opaque-fail.stderr
+++ b/tests/ui/hygiene/extern-prelude-from-opaque-fail.stderr
@@ -15,25 +15,27 @@ LL | a!();
    |
    = note: this error originates in the macro `a` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error[E0433]: failed to resolve: use of undeclared crate or module `my_core`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `my_core`
   --> $DIR/extern-prelude-from-opaque-fail.rs:12:18
    |
 LL |         fn f() { my_core::mem::drop(0); }
-   |                  ^^^^^^^ use of undeclared crate or module `my_core`
+   |                  ^^^^^^^ use of unresolved module or unlinked crate `my_core`
 ...
 LL | a!();
    | ---- in this macro invocation
    |
+   = help: you might be missing a crate named `my_core`
    = help: consider importing this module:
            my_core::mem
    = note: this error originates in the macro `a` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error[E0433]: failed to resolve: use of undeclared crate or module `my_core`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `my_core`
   --> $DIR/extern-prelude-from-opaque-fail.rs:25:14
    |
 LL |     fn f() { my_core::mem::drop(0); }
-   |              ^^^^^^^ use of undeclared crate or module `my_core`
+   |              ^^^^^^^ use of unresolved module or unlinked crate `my_core`
    |
+   = help: you might be missing a crate named `my_core`
 help: consider importing this module
    |
 LL +     use my_core::mem;
diff --git a/tests/ui/impl-trait/issue-72911.stderr b/tests/ui/impl-trait/issue-72911.stderr
index 0e86561aa2779..063b7f68dc02a 100644
--- a/tests/ui/impl-trait/issue-72911.stderr
+++ b/tests/ui/impl-trait/issue-72911.stderr
@@ -1,14 +1,18 @@
-error[E0433]: failed to resolve: use of undeclared crate or module `foo`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `foo`
   --> $DIR/issue-72911.rs:11:33
    |
 LL | fn gather_from_file(dir_entry: &foo::MissingItem) -> impl Iterator<Item = Lint> {
-   |                                 ^^^ use of undeclared crate or module `foo`
+   |                                 ^^^ use of unresolved module or unlinked crate `foo`
+   |
+   = help: you might be missing a crate named `foo`
 
-error[E0433]: failed to resolve: use of undeclared crate or module `foo`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `foo`
   --> $DIR/issue-72911.rs:16:41
    |
 LL | fn lint_files() -> impl Iterator<Item = foo::MissingItem> {
-   |                                         ^^^ use of undeclared crate or module `foo`
+   |                                         ^^^ use of unresolved module or unlinked crate `foo`
+   |
+   = help: you might be missing a crate named `foo`
 
 error: aborting due to 2 previous errors
 
diff --git a/tests/ui/impl-trait/stashed-diag-issue-121504.rs b/tests/ui/impl-trait/stashed-diag-issue-121504.rs
index 4ac8ffe8931c6..84686ba4f7d3d 100644
--- a/tests/ui/impl-trait/stashed-diag-issue-121504.rs
+++ b/tests/ui/impl-trait/stashed-diag-issue-121504.rs
@@ -4,7 +4,7 @@ trait MyTrait {
     async fn foo(self) -> (Self, i32);
 }
 
-impl MyTrait for xyz::T { //~ ERROR failed to resolve: use of undeclared crate or module `xyz`
+impl MyTrait for xyz::T { //~ ERROR failed to resolve: use of unresolved module or unlinked crate `xyz`
     async fn foo(self, key: i32) -> (u32, i32) {
         (self, key)
     }
diff --git a/tests/ui/impl-trait/stashed-diag-issue-121504.stderr b/tests/ui/impl-trait/stashed-diag-issue-121504.stderr
index 6a881dc7f9fbd..41c6cc425558d 100644
--- a/tests/ui/impl-trait/stashed-diag-issue-121504.stderr
+++ b/tests/ui/impl-trait/stashed-diag-issue-121504.stderr
@@ -1,8 +1,10 @@
-error[E0433]: failed to resolve: use of undeclared crate or module `xyz`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `xyz`
   --> $DIR/stashed-diag-issue-121504.rs:7:18
    |
 LL | impl MyTrait for xyz::T {
-   |                  ^^^ use of undeclared crate or module `xyz`
+   |                  ^^^ use of unresolved module or unlinked crate `xyz`
+   |
+   = help: you might be missing a crate named `xyz`
 
 error: aborting due to 1 previous error
 
diff --git a/tests/ui/imports/extern-prelude-extern-crate-fail.rs b/tests/ui/imports/extern-prelude-extern-crate-fail.rs
index 2f018851d1936..84751ecc02b63 100644
--- a/tests/ui/imports/extern-prelude-extern-crate-fail.rs
+++ b/tests/ui/imports/extern-prelude-extern-crate-fail.rs
@@ -7,7 +7,7 @@ mod n {
 
 mod m {
     fn check() {
-        two_macros::m!(); //~ ERROR failed to resolve: use of undeclared crate or module `two_macros`
+        two_macros::m!(); //~ ERROR failed to resolve: use of unresolved module or unlinked crate `two_macros`
     }
 }
 
diff --git a/tests/ui/imports/extern-prelude-extern-crate-fail.stderr b/tests/ui/imports/extern-prelude-extern-crate-fail.stderr
index f7e37449eebe5..ec53730afa024 100644
--- a/tests/ui/imports/extern-prelude-extern-crate-fail.stderr
+++ b/tests/ui/imports/extern-prelude-extern-crate-fail.stderr
@@ -9,11 +9,11 @@ LL | define_std_as_non_existent!();
    |
    = note: this error originates in the macro `define_std_as_non_existent` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error[E0433]: failed to resolve: use of undeclared crate or module `two_macros`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `two_macros`
   --> $DIR/extern-prelude-extern-crate-fail.rs:10:9
    |
 LL |         two_macros::m!();
-   |         ^^^^^^^^^^ use of undeclared crate or module `two_macros`
+   |         ^^^^^^^^^^ use of unresolved module or unlinked crate `two_macros`
 
 error: aborting due to 2 previous errors
 
diff --git a/tests/ui/imports/import-from-missing-star-2.stderr b/tests/ui/imports/import-from-missing-star-2.stderr
index dd35627c68465..9fe2bdbcfa279 100644
--- a/tests/ui/imports/import-from-missing-star-2.stderr
+++ b/tests/ui/imports/import-from-missing-star-2.stderr
@@ -2,9 +2,9 @@ error[E0432]: unresolved import `spam`
   --> $DIR/import-from-missing-star-2.rs:2:9
    |
 LL |     use spam::*;
-   |         ^^^^ you might be missing crate `spam`
+   |         ^^^^ use of unresolved module or unlinked crate `spam`
    |
-help: consider importing the `spam` crate
+help: you might be missing a crate named `spam`, add it to your project and import it in your code
    |
 LL + extern crate spam;
    |
diff --git a/tests/ui/imports/import-from-missing-star-3.stderr b/tests/ui/imports/import-from-missing-star-3.stderr
index 1e2412b095975..c0b2e5675d391 100644
--- a/tests/ui/imports/import-from-missing-star-3.stderr
+++ b/tests/ui/imports/import-from-missing-star-3.stderr
@@ -2,9 +2,9 @@ error[E0432]: unresolved import `spam`
   --> $DIR/import-from-missing-star-3.rs:2:9
    |
 LL |     use spam::*;
-   |         ^^^^ you might be missing crate `spam`
+   |         ^^^^ use of unresolved module or unlinked crate `spam`
    |
-help: consider importing the `spam` crate
+help: you might be missing a crate named `spam`, add it to your project and import it in your code
    |
 LL + extern crate spam;
    |
@@ -13,9 +13,9 @@ error[E0432]: unresolved import `spam`
   --> $DIR/import-from-missing-star-3.rs:27:13
    |
 LL |         use spam::*;
-   |             ^^^^ you might be missing crate `spam`
+   |             ^^^^ use of unresolved module or unlinked crate `spam`
    |
-help: consider importing the `spam` crate
+help: you might be missing a crate named `spam`, add it to your project and import it in your code
    |
 LL + extern crate spam;
    |
diff --git a/tests/ui/imports/import-from-missing-star.stderr b/tests/ui/imports/import-from-missing-star.stderr
index c9bb9baeb4dde..768e1ea1e2cf8 100644
--- a/tests/ui/imports/import-from-missing-star.stderr
+++ b/tests/ui/imports/import-from-missing-star.stderr
@@ -2,9 +2,9 @@ error[E0432]: unresolved import `spam`
   --> $DIR/import-from-missing-star.rs:1:5
    |
 LL | use spam::*;
-   |     ^^^^ you might be missing crate `spam`
+   |     ^^^^ use of unresolved module or unlinked crate `spam`
    |
-help: consider importing the `spam` crate
+help: you might be missing a crate named `spam`, add it to your project and import it in your code
    |
 LL + extern crate spam;
    |
diff --git a/tests/ui/imports/import3.stderr b/tests/ui/imports/import3.stderr
index 157b5b6356687..7f58114678117 100644
--- a/tests/ui/imports/import3.stderr
+++ b/tests/ui/imports/import3.stderr
@@ -2,9 +2,9 @@ error[E0432]: unresolved import `main`
   --> $DIR/import3.rs:2:5
    |
 LL | use main::bar;
-   |     ^^^^ you might be missing crate `main`
+   |     ^^^^ use of unresolved module or unlinked crate `main`
    |
-help: consider importing the `main` crate
+help: you might be missing a crate named `main`, add it to your project and import it in your code
    |
 LL + extern crate main;
    |
diff --git a/tests/ui/imports/issue-109343.stderr b/tests/ui/imports/issue-109343.stderr
index e66528e8df528..e1071e45b924c 100644
--- a/tests/ui/imports/issue-109343.stderr
+++ b/tests/ui/imports/issue-109343.stderr
@@ -2,9 +2,9 @@ error[E0432]: unresolved import `unresolved`
   --> $DIR/issue-109343.rs:4:9
    |
 LL | pub use unresolved::f;
-   |         ^^^^^^^^^^ you might be missing crate `unresolved`
+   |         ^^^^^^^^^^ use of unresolved module or unlinked crate `unresolved`
    |
-help: consider importing the `unresolved` crate
+help: you might be missing a crate named `unresolved`, add it to your project and import it in your code
    |
 LL + extern crate unresolved;
    |
diff --git a/tests/ui/imports/issue-1697.rs b/tests/ui/imports/issue-1697.rs
index 019237611df0d..3d3d4a17d6c19 100644
--- a/tests/ui/imports/issue-1697.rs
+++ b/tests/ui/imports/issue-1697.rs
@@ -2,7 +2,7 @@
 
 use unresolved::*;
 //~^ ERROR unresolved import `unresolved` [E0432]
-//~| NOTE you might be missing crate `unresolved`
-//~| HELP consider importing the `unresolved` crate
+//~| NOTE use of unresolved module or unlinked crate `unresolved`
+//~| HELP you might be missing a crate named `unresolved`
 
 fn main() {}
diff --git a/tests/ui/imports/issue-1697.stderr b/tests/ui/imports/issue-1697.stderr
index ec0d94bd672f9..96e371c64f9e5 100644
--- a/tests/ui/imports/issue-1697.stderr
+++ b/tests/ui/imports/issue-1697.stderr
@@ -2,9 +2,9 @@ error[E0432]: unresolved import `unresolved`
   --> $DIR/issue-1697.rs:3:5
    |
 LL | use unresolved::*;
-   |     ^^^^^^^^^^ you might be missing crate `unresolved`
+   |     ^^^^^^^^^^ use of unresolved module or unlinked crate `unresolved`
    |
-help: consider importing the `unresolved` crate
+help: you might be missing a crate named `unresolved`, add it to your project and import it in your code
    |
 LL + extern crate unresolved;
    |
diff --git a/tests/ui/imports/issue-33464.stderr b/tests/ui/imports/issue-33464.stderr
index 28fbcee401f91..dba4518467580 100644
--- a/tests/ui/imports/issue-33464.stderr
+++ b/tests/ui/imports/issue-33464.stderr
@@ -2,9 +2,9 @@ error[E0432]: unresolved import `abc`
   --> $DIR/issue-33464.rs:3:5
    |
 LL | use abc::one_el;
-   |     ^^^ you might be missing crate `abc`
+   |     ^^^ use of unresolved module or unlinked crate `abc`
    |
-help: consider importing the `abc` crate
+help: you might be missing a crate named `abc`, add it to your project and import it in your code
    |
 LL + extern crate abc;
    |
@@ -13,9 +13,9 @@ error[E0432]: unresolved import `abc`
   --> $DIR/issue-33464.rs:5:5
    |
 LL | use abc::{a, bbb, cccccc};
-   |     ^^^ you might be missing crate `abc`
+   |     ^^^ use of unresolved module or unlinked crate `abc`
    |
-help: consider importing the `abc` crate
+help: you might be missing a crate named `abc`, add it to your project and import it in your code
    |
 LL + extern crate abc;
    |
@@ -24,9 +24,9 @@ error[E0432]: unresolved import `a_very_long_name`
   --> $DIR/issue-33464.rs:7:5
    |
 LL | use a_very_long_name::{el, el2};
-   |     ^^^^^^^^^^^^^^^^ you might be missing crate `a_very_long_name`
+   |     ^^^^^^^^^^^^^^^^ use of unresolved module or unlinked crate `a_very_long_name`
    |
-help: consider importing the `a_very_long_name` crate
+help: you might be missing a crate named `a_very_long_name`, add it to your project and import it in your code
    |
 LL + extern crate a_very_long_name;
    |
diff --git a/tests/ui/imports/issue-36881.stderr b/tests/ui/imports/issue-36881.stderr
index 004836e072c5e..33d628f40da22 100644
--- a/tests/ui/imports/issue-36881.stderr
+++ b/tests/ui/imports/issue-36881.stderr
@@ -2,9 +2,9 @@ error[E0432]: unresolved import `issue_36881_aux`
   --> $DIR/issue-36881.rs:5:9
    |
 LL |     use issue_36881_aux::Foo;
-   |         ^^^^^^^^^^^^^^^ you might be missing crate `issue_36881_aux`
+   |         ^^^^^^^^^^^^^^^ use of unresolved module or unlinked crate `issue_36881_aux`
    |
-help: consider importing the `issue_36881_aux` crate
+help: you might be missing a crate named `issue_36881_aux`, add it to your project and import it in your code
    |
 LL + extern crate issue_36881_aux;
    |
diff --git a/tests/ui/imports/issue-37887.stderr b/tests/ui/imports/issue-37887.stderr
index cc191a17c2936..b83ba273a0194 100644
--- a/tests/ui/imports/issue-37887.stderr
+++ b/tests/ui/imports/issue-37887.stderr
@@ -2,9 +2,9 @@ error[E0432]: unresolved import `test`
   --> $DIR/issue-37887.rs:3:9
    |
 LL |     use test::*;
-   |         ^^^^ you might be missing crate `test`
+   |         ^^^^ use of unresolved module or unlinked crate `test`
    |
-help: consider importing the `test` crate
+help: you might be missing a crate named `test`, add it to your project and import it in your code
    |
 LL + extern crate test;
    |
diff --git a/tests/ui/imports/issue-53269.stderr b/tests/ui/imports/issue-53269.stderr
index d25d85bf46f02..c12fc0f378e81 100644
--- a/tests/ui/imports/issue-53269.stderr
+++ b/tests/ui/imports/issue-53269.stderr
@@ -2,9 +2,9 @@ error[E0432]: unresolved import `nonexistent_module`
   --> $DIR/issue-53269.rs:6:9
    |
 LL |     use nonexistent_module::mac;
-   |         ^^^^^^^^^^^^^^^^^^ you might be missing crate `nonexistent_module`
+   |         ^^^^^^^^^^^^^^^^^^ use of unresolved module or unlinked crate `nonexistent_module`
    |
-help: consider importing the `nonexistent_module` crate
+help: you might be missing a crate named `nonexistent_module`, add it to your project and import it in your code
    |
 LL + extern crate nonexistent_module;
    |
diff --git a/tests/ui/imports/issue-55457.stderr b/tests/ui/imports/issue-55457.stderr
index 9c99b6a20de7c..472e46caf31e1 100644
--- a/tests/ui/imports/issue-55457.stderr
+++ b/tests/ui/imports/issue-55457.stderr
@@ -11,9 +11,9 @@ error[E0432]: unresolved import `non_existent`
   --> $DIR/issue-55457.rs:2:5
    |
 LL | use non_existent::non_existent;
-   |     ^^^^^^^^^^^^ you might be missing crate `non_existent`
+   |     ^^^^^^^^^^^^ use of unresolved module or unlinked crate `non_existent`
    |
-help: consider importing the `non_existent` crate
+help: you might be missing a crate named `non_existent`, add it to your project and import it in your code
    |
 LL + extern crate non_existent;
    |
diff --git a/tests/ui/imports/issue-81413.stderr b/tests/ui/imports/issue-81413.stderr
index aa1246c1d2f50..257aca4455c5d 100644
--- a/tests/ui/imports/issue-81413.stderr
+++ b/tests/ui/imports/issue-81413.stderr
@@ -2,9 +2,9 @@ error[E0432]: unresolved import `doesnt_exist`
   --> $DIR/issue-81413.rs:7:9
    |
 LL | pub use doesnt_exist::*;
-   |         ^^^^^^^^^^^^ you might be missing crate `doesnt_exist`
+   |         ^^^^^^^^^^^^ use of unresolved module or unlinked crate `doesnt_exist`
    |
-help: consider importing the `doesnt_exist` crate
+help: you might be missing a crate named `doesnt_exist`, add it to your project and import it in your code
    |
 LL + extern crate doesnt_exist;
    |
diff --git a/tests/ui/imports/tool-mod-child.rs b/tests/ui/imports/tool-mod-child.rs
index a8249ab01dfc1..38bcdfb024941 100644
--- a/tests/ui/imports/tool-mod-child.rs
+++ b/tests/ui/imports/tool-mod-child.rs
@@ -1,7 +1,7 @@
 use clippy::a; //~ ERROR unresolved import `clippy`
-use clippy::a::b; //~ ERROR failed to resolve: you might be missing crate `clippy`
+use clippy::a::b; //~ ERROR failed to resolve: use of unresolved module or unlinked crate `clippy`
 
 use rustdoc::a; //~ ERROR unresolved import `rustdoc`
-use rustdoc::a::b; //~ ERROR failed to resolve: you might be missing crate `rustdoc`
+use rustdoc::a::b; //~ ERROR failed to resolve: use of unresolved module or unlinked crate `rustdoc`
 
 fn main() {}
diff --git a/tests/ui/imports/tool-mod-child.stderr b/tests/ui/imports/tool-mod-child.stderr
index ec110ccd75dbc..b0e446fcbf6a7 100644
--- a/tests/ui/imports/tool-mod-child.stderr
+++ b/tests/ui/imports/tool-mod-child.stderr
@@ -1,10 +1,10 @@
-error[E0433]: failed to resolve: you might be missing crate `clippy`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `clippy`
   --> $DIR/tool-mod-child.rs:2:5
    |
 LL | use clippy::a::b;
-   |     ^^^^^^ you might be missing crate `clippy`
+   |     ^^^^^^ use of unresolved module or unlinked crate `clippy`
    |
-help: consider importing the `clippy` crate
+help: you might be missing a crate named `clippy`, add it to your project and import it in your code
    |
 LL + extern crate clippy;
    |
@@ -13,20 +13,20 @@ error[E0432]: unresolved import `clippy`
   --> $DIR/tool-mod-child.rs:1:5
    |
 LL | use clippy::a;
-   |     ^^^^^^ you might be missing crate `clippy`
+   |     ^^^^^^ use of unresolved module or unlinked crate `clippy`
    |
-help: consider importing the `clippy` crate
+help: you might be missing a crate named `clippy`, add it to your project and import it in your code
    |
 LL + extern crate clippy;
    |
 
-error[E0433]: failed to resolve: you might be missing crate `rustdoc`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `rustdoc`
   --> $DIR/tool-mod-child.rs:5:5
    |
 LL | use rustdoc::a::b;
-   |     ^^^^^^^ you might be missing crate `rustdoc`
+   |     ^^^^^^^ use of unresolved module or unlinked crate `rustdoc`
    |
-help: consider importing the `rustdoc` crate
+help: you might be missing a crate named `rustdoc`, add it to your project and import it in your code
    |
 LL + extern crate rustdoc;
    |
@@ -35,9 +35,9 @@ error[E0432]: unresolved import `rustdoc`
   --> $DIR/tool-mod-child.rs:4:5
    |
 LL | use rustdoc::a;
-   |     ^^^^^^^ you might be missing crate `rustdoc`
+   |     ^^^^^^^ use of unresolved module or unlinked crate `rustdoc`
    |
-help: consider importing the `rustdoc` crate
+help: you might be missing a crate named `rustdoc`, add it to your project and import it in your code
    |
 LL + extern crate rustdoc;
    |
diff --git a/tests/ui/imports/unresolved-imports-used.stderr b/tests/ui/imports/unresolved-imports-used.stderr
index 4bf02ff6e3a9f..d39d268521718 100644
--- a/tests/ui/imports/unresolved-imports-used.stderr
+++ b/tests/ui/imports/unresolved-imports-used.stderr
@@ -14,9 +14,9 @@ error[E0432]: unresolved import `foo`
   --> $DIR/unresolved-imports-used.rs:11:5
    |
 LL | use foo::bar;
-   |     ^^^ you might be missing crate `foo`
+   |     ^^^ use of unresolved module or unlinked crate `foo`
    |
-help: consider importing the `foo` crate
+help: you might be missing a crate named `foo`, add it to your project and import it in your code
    |
 LL + extern crate foo;
    |
@@ -25,9 +25,9 @@ error[E0432]: unresolved import `baz`
   --> $DIR/unresolved-imports-used.rs:12:5
    |
 LL | use baz::*;
-   |     ^^^ you might be missing crate `baz`
+   |     ^^^ use of unresolved module or unlinked crate `baz`
    |
-help: consider importing the `baz` crate
+help: you might be missing a crate named `baz`, add it to your project and import it in your code
    |
 LL + extern crate baz;
    |
@@ -36,9 +36,9 @@ error[E0432]: unresolved import `foo2`
   --> $DIR/unresolved-imports-used.rs:14:5
    |
 LL | use foo2::bar2;
-   |     ^^^^ you might be missing crate `foo2`
+   |     ^^^^ use of unresolved module or unlinked crate `foo2`
    |
-help: consider importing the `foo2` crate
+help: you might be missing a crate named `foo2`, add it to your project and import it in your code
    |
 LL + extern crate foo2;
    |
@@ -47,9 +47,9 @@ error[E0432]: unresolved import `baz2`
   --> $DIR/unresolved-imports-used.rs:15:5
    |
 LL | use baz2::*;
-   |     ^^^^ you might be missing crate `baz2`
+   |     ^^^^ use of unresolved module or unlinked crate `baz2`
    |
-help: consider importing the `baz2` crate
+help: you might be missing a crate named `baz2`, add it to your project and import it in your code
    |
 LL + extern crate baz2;
    |
diff --git a/tests/ui/issues/issue-33293.rs b/tests/ui/issues/issue-33293.rs
index a6ef007d51fb5..115ae3aad204c 100644
--- a/tests/ui/issues/issue-33293.rs
+++ b/tests/ui/issues/issue-33293.rs
@@ -1,6 +1,6 @@
 fn main() {
     match 0 {
         aaa::bbb(_) => ()
-        //~^ ERROR failed to resolve: use of undeclared crate or module `aaa`
+        //~^ ERROR failed to resolve: use of unresolved module or unlinked crate `aaa`
     };
 }
diff --git a/tests/ui/issues/issue-33293.stderr b/tests/ui/issues/issue-33293.stderr
index 5badaa153f2b1..a82813194d77b 100644
--- a/tests/ui/issues/issue-33293.stderr
+++ b/tests/ui/issues/issue-33293.stderr
@@ -1,8 +1,10 @@
-error[E0433]: failed to resolve: use of undeclared crate or module `aaa`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `aaa`
   --> $DIR/issue-33293.rs:3:9
    |
 LL |         aaa::bbb(_) => ()
-   |         ^^^ use of undeclared crate or module `aaa`
+   |         ^^^ use of unresolved module or unlinked crate `aaa`
+   |
+   = help: you might be missing a crate named `aaa`
 
 error: aborting due to 1 previous error
 
diff --git a/tests/ui/keyword/extern/keyword-extern-as-identifier-use.stderr b/tests/ui/keyword/extern/keyword-extern-as-identifier-use.stderr
index f23f855c9e8e8..dab68258a4720 100644
--- a/tests/ui/keyword/extern/keyword-extern-as-identifier-use.stderr
+++ b/tests/ui/keyword/extern/keyword-extern-as-identifier-use.stderr
@@ -13,9 +13,9 @@ error[E0432]: unresolved import `r#extern`
   --> $DIR/keyword-extern-as-identifier-use.rs:1:5
    |
 LL | use extern::foo;
-   |     ^^^^^^ you might be missing crate `r#extern`
+   |     ^^^^^^ use of unresolved module or unlinked crate `r#extern`
    |
-help: consider importing the `r#extern` crate
+help: you might be missing a crate named `r#extern`, add it to your project and import it in your code
    |
 LL + extern crate r#extern;
    |
diff --git a/tests/ui/macros/builtin-prelude-no-accidents.rs b/tests/ui/macros/builtin-prelude-no-accidents.rs
index 01691a82dd772..9bebcb75526fb 100644
--- a/tests/ui/macros/builtin-prelude-no-accidents.rs
+++ b/tests/ui/macros/builtin-prelude-no-accidents.rs
@@ -2,7 +2,7 @@
 // because macros with the same names are in prelude.
 
 fn main() {
-    env::current_dir; //~ ERROR use of undeclared crate or module `env`
-    type A = panic::PanicInfo; //~ ERROR use of undeclared crate or module `panic`
-    type B = vec::Vec<u8>; //~ ERROR use of undeclared crate or module `vec`
+    env::current_dir; //~ ERROR use of unresolved module or unlinked crate `env`
+    type A = panic::PanicInfo; //~ ERROR use of unresolved module or unlinked crate `panic`
+    type B = vec::Vec<u8>; //~ ERROR use of unresolved module or unlinked crate `vec`
 }
diff --git a/tests/ui/macros/builtin-prelude-no-accidents.stderr b/tests/ui/macros/builtin-prelude-no-accidents.stderr
index c1054230bc9a5..8c7095a6aedf3 100644
--- a/tests/ui/macros/builtin-prelude-no-accidents.stderr
+++ b/tests/ui/macros/builtin-prelude-no-accidents.stderr
@@ -1,31 +1,34 @@
-error[E0433]: failed to resolve: use of undeclared crate or module `env`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `env`
   --> $DIR/builtin-prelude-no-accidents.rs:5:5
    |
 LL |     env::current_dir;
-   |     ^^^ use of undeclared crate or module `env`
+   |     ^^^ use of unresolved module or unlinked crate `env`
    |
+   = help: you might be missing a crate named `env`
 help: consider importing this module
    |
 LL + use std::env;
    |
 
-error[E0433]: failed to resolve: use of undeclared crate or module `panic`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `panic`
   --> $DIR/builtin-prelude-no-accidents.rs:6:14
    |
 LL |     type A = panic::PanicInfo;
-   |              ^^^^^ use of undeclared crate or module `panic`
+   |              ^^^^^ use of unresolved module or unlinked crate `panic`
    |
+   = help: you might be missing a crate named `panic`
 help: consider importing this module
    |
 LL + use std::panic;
    |
 
-error[E0433]: failed to resolve: use of undeclared crate or module `vec`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `vec`
   --> $DIR/builtin-prelude-no-accidents.rs:7:14
    |
 LL |     type B = vec::Vec<u8>;
-   |              ^^^ use of undeclared crate or module `vec`
+   |              ^^^ use of unresolved module or unlinked crate `vec`
    |
+   = help: you might be missing a crate named `vec`
 help: consider importing this module
    |
 LL + use std::vec;
diff --git a/tests/ui/macros/macro-inner-attributes.rs b/tests/ui/macros/macro-inner-attributes.rs
index 6dbfce2135989..a1eb7cd15c4cc 100644
--- a/tests/ui/macros/macro-inner-attributes.rs
+++ b/tests/ui/macros/macro-inner-attributes.rs
@@ -15,6 +15,6 @@ test!(b,
 #[rustc_dummy]
 fn main() {
     a::bar();
-    //~^ ERROR failed to resolve: use of undeclared crate or module `a`
+    //~^ ERROR failed to resolve: use of unresolved module or unlinked crate `a`
     b::bar();
 }
diff --git a/tests/ui/macros/macro-inner-attributes.stderr b/tests/ui/macros/macro-inner-attributes.stderr
index b6e10f45e3810..947e33b08f4a2 100644
--- a/tests/ui/macros/macro-inner-attributes.stderr
+++ b/tests/ui/macros/macro-inner-attributes.stderr
@@ -1,8 +1,8 @@
-error[E0433]: failed to resolve: use of undeclared crate or module `a`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `a`
   --> $DIR/macro-inner-attributes.rs:17:5
    |
 LL |     a::bar();
-   |     ^ use of undeclared crate or module `a`
+   |     ^ use of unresolved module or unlinked crate `a`
    |
 help: there is a crate or module with a similar name
    |
diff --git a/tests/ui/macros/macro_path_as_generic_bound.stderr b/tests/ui/macros/macro_path_as_generic_bound.stderr
index e25ff57e57f36..9fe4ad27aa059 100644
--- a/tests/ui/macros/macro_path_as_generic_bound.stderr
+++ b/tests/ui/macros/macro_path_as_generic_bound.stderr
@@ -1,8 +1,10 @@
-error[E0433]: failed to resolve: use of undeclared crate or module `m`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `m`
   --> $DIR/macro_path_as_generic_bound.rs:7:6
    |
 LL | foo!(m::m2::A);
-   |      ^ use of undeclared crate or module `m`
+   |      ^ use of unresolved module or unlinked crate `m`
+   |
+   = help: you might be missing a crate named `m`
 
 error: aborting due to 1 previous error
 
diff --git a/tests/ui/macros/meta-item-absolute-path.stderr b/tests/ui/macros/meta-item-absolute-path.stderr
index af56d935284cc..8fa5e97899ca2 100644
--- a/tests/ui/macros/meta-item-absolute-path.stderr
+++ b/tests/ui/macros/meta-item-absolute-path.stderr
@@ -1,14 +1,14 @@
-error[E0433]: failed to resolve: you might be missing crate `Absolute`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `Absolute`
   --> $DIR/meta-item-absolute-path.rs:1:12
    |
 LL | #[derive(::Absolute)]
-   |            ^^^^^^^^ you might be missing crate `Absolute`
+   |            ^^^^^^^^ use of unresolved module or unlinked crate `Absolute`
 
-error[E0433]: failed to resolve: you might be missing crate `Absolute`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `Absolute`
   --> $DIR/meta-item-absolute-path.rs:1:12
    |
 LL | #[derive(::Absolute)]
-   |            ^^^^^^^^ you might be missing crate `Absolute`
+   |            ^^^^^^^^ use of unresolved module or unlinked crate `Absolute`
    |
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
diff --git a/tests/ui/mir/issue-121103.rs b/tests/ui/mir/issue-121103.rs
index e06361a6964c0..247c644c5bb19 100644
--- a/tests/ui/mir/issue-121103.rs
+++ b/tests/ui/mir/issue-121103.rs
@@ -1,3 +1,3 @@
 fn main(_: <lib2::GenericType<42> as lib2::TypeFn>::Output) {}
-//~^ ERROR failed to resolve: use of undeclared crate or module `lib2`
-//~| ERROR failed to resolve: use of undeclared crate or module `lib2`
+//~^ ERROR failed to resolve: use of unresolved module or unlinked crate `lib2`
+//~| ERROR failed to resolve: use of unresolved module or unlinked crate `lib2`
diff --git a/tests/ui/mir/issue-121103.stderr b/tests/ui/mir/issue-121103.stderr
index 913eee9e0c503..3565f6f0cdeff 100644
--- a/tests/ui/mir/issue-121103.stderr
+++ b/tests/ui/mir/issue-121103.stderr
@@ -1,14 +1,18 @@
-error[E0433]: failed to resolve: use of undeclared crate or module `lib2`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `lib2`
   --> $DIR/issue-121103.rs:1:38
    |
 LL | fn main(_: <lib2::GenericType<42> as lib2::TypeFn>::Output) {}
-   |                                      ^^^^ use of undeclared crate or module `lib2`
+   |                                      ^^^^ use of unresolved module or unlinked crate `lib2`
+   |
+   = help: you might be missing a crate named `lib2`
 
-error[E0433]: failed to resolve: use of undeclared crate or module `lib2`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `lib2`
   --> $DIR/issue-121103.rs:1:13
    |
 LL | fn main(_: <lib2::GenericType<42> as lib2::TypeFn>::Output) {}
-   |             ^^^^ use of undeclared crate or module `lib2`
+   |             ^^^^ use of unresolved module or unlinked crate `lib2`
+   |
+   = help: you might be missing a crate named `lib2`
 
 error: aborting due to 2 previous errors
 
diff --git a/tests/ui/modules_and_files_visibility/mod_file_disambig.rs b/tests/ui/modules_and_files_visibility/mod_file_disambig.rs
index e5958af173b66..1483e3e4630c2 100644
--- a/tests/ui/modules_and_files_visibility/mod_file_disambig.rs
+++ b/tests/ui/modules_and_files_visibility/mod_file_disambig.rs
@@ -2,5 +2,5 @@ mod mod_file_disambig_aux; //~ ERROR file for module `mod_file_disambig_aux` fou
 
 fn main() {
     assert_eq!(mod_file_aux::bar(), 10);
-    //~^ ERROR failed to resolve: use of undeclared crate or module `mod_file_aux`
+    //~^ ERROR failed to resolve: use of unresolved module or unlinked crate `mod_file_aux`
 }
diff --git a/tests/ui/modules_and_files_visibility/mod_file_disambig.stderr b/tests/ui/modules_and_files_visibility/mod_file_disambig.stderr
index a2c99396987ef..f82d613015f5d 100644
--- a/tests/ui/modules_and_files_visibility/mod_file_disambig.stderr
+++ b/tests/ui/modules_and_files_visibility/mod_file_disambig.stderr
@@ -6,11 +6,13 @@ LL | mod mod_file_disambig_aux;
    |
    = help: delete or rename one of them to remove the ambiguity
 
-error[E0433]: failed to resolve: use of undeclared crate or module `mod_file_aux`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `mod_file_aux`
   --> $DIR/mod_file_disambig.rs:4:16
    |
 LL |     assert_eq!(mod_file_aux::bar(), 10);
-   |                ^^^^^^^^^^^^ use of undeclared crate or module `mod_file_aux`
+   |                ^^^^^^^^^^^^ use of unresolved module or unlinked crate `mod_file_aux`
+   |
+   = help: you might be missing a crate named `mod_file_aux`
 
 error: aborting due to 2 previous errors
 
diff --git a/tests/ui/parser/const-param-decl-on-type-instead-of-impl.rs b/tests/ui/parser/const-param-decl-on-type-instead-of-impl.rs
index 53e3c6f960500..3876fb41d23f1 100644
--- a/tests/ui/parser/const-param-decl-on-type-instead-of-impl.rs
+++ b/tests/ui/parser/const-param-decl-on-type-instead-of-impl.rs
@@ -11,5 +11,5 @@ fn banana(a: <T<const N: usize>>::BAR) {}
 fn chaenomeles() {
     path::path::Struct::<const N: usize>()
     //~^ ERROR unexpected `const` parameter declaration
-    //~| ERROR failed to resolve: use of undeclared crate or module `path`
+    //~| ERROR failed to resolve: use of unresolved module or unlinked crate `path`
 }
diff --git a/tests/ui/parser/const-param-decl-on-type-instead-of-impl.stderr b/tests/ui/parser/const-param-decl-on-type-instead-of-impl.stderr
index 96885d11ee07f..104dbd02685be 100644
--- a/tests/ui/parser/const-param-decl-on-type-instead-of-impl.stderr
+++ b/tests/ui/parser/const-param-decl-on-type-instead-of-impl.stderr
@@ -21,11 +21,13 @@ error: unexpected `const` parameter declaration
 LL |     path::path::Struct::<const N: usize>()
    |                          ^^^^^^^^^^^^^^ expected a `const` expression, not a parameter declaration
 
-error[E0433]: failed to resolve: use of undeclared crate or module `path`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `path`
   --> $DIR/const-param-decl-on-type-instead-of-impl.rs:12:5
    |
 LL |     path::path::Struct::<const N: usize>()
-   |     ^^^^ use of undeclared crate or module `path`
+   |     ^^^^ use of unresolved module or unlinked crate `path`
+   |
+   = help: you might be missing a crate named `path`
 
 error[E0412]: cannot find type `T` in this scope
   --> $DIR/const-param-decl-on-type-instead-of-impl.rs:8:15
diff --git a/tests/ui/parser/dyn-trait-compatibility.rs b/tests/ui/parser/dyn-trait-compatibility.rs
index 6341e05327754..717b14c5941fd 100644
--- a/tests/ui/parser/dyn-trait-compatibility.rs
+++ b/tests/ui/parser/dyn-trait-compatibility.rs
@@ -1,7 +1,7 @@
 type A0 = dyn;
 //~^ ERROR cannot find type `dyn` in this scope
 type A1 = dyn::dyn;
-//~^ ERROR use of undeclared crate or module `dyn`
+//~^ ERROR use of unresolved module or unlinked crate `dyn`
 type A2 = dyn<dyn, dyn>;
 //~^ ERROR cannot find type `dyn` in this scope
 //~| ERROR cannot find type `dyn` in this scope
diff --git a/tests/ui/parser/dyn-trait-compatibility.stderr b/tests/ui/parser/dyn-trait-compatibility.stderr
index e34d855a9d4f9..08e0a50010a88 100644
--- a/tests/ui/parser/dyn-trait-compatibility.stderr
+++ b/tests/ui/parser/dyn-trait-compatibility.stderr
@@ -40,11 +40,13 @@ error[E0412]: cannot find type `dyn` in this scope
 LL | type A3 = dyn<<dyn as dyn>::dyn>;
    |                ^^^ not found in this scope
 
-error[E0433]: failed to resolve: use of undeclared crate or module `dyn`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `dyn`
   --> $DIR/dyn-trait-compatibility.rs:3:11
    |
 LL | type A1 = dyn::dyn;
-   |           ^^^ use of undeclared crate or module `dyn`
+   |           ^^^ use of unresolved module or unlinked crate `dyn`
+   |
+   = help: you might be missing a crate named `dyn`
 
 error: aborting due to 8 previous errors
 
diff --git a/tests/ui/parser/mod_file_not_exist.rs b/tests/ui/parser/mod_file_not_exist.rs
index 80a17163087c9..e7727944147e4 100644
--- a/tests/ui/parser/mod_file_not_exist.rs
+++ b/tests/ui/parser/mod_file_not_exist.rs
@@ -5,5 +5,6 @@ mod not_a_real_file; //~ ERROR file not found for module `not_a_real_file`
 
 fn main() {
     assert_eq!(mod_file_aux::bar(), 10);
-    //~^ ERROR failed to resolve: use of undeclared crate or module `mod_file_aux`
+    //~^ ERROR failed to resolve: use of unresolved module or unlinked crate `mod_file_aux`
+    //~| HELP you might be missing a crate named `mod_file_aux`
 }
diff --git a/tests/ui/parser/mod_file_not_exist.stderr b/tests/ui/parser/mod_file_not_exist.stderr
index c2f9d30d9ec40..40041b11c8b82 100644
--- a/tests/ui/parser/mod_file_not_exist.stderr
+++ b/tests/ui/parser/mod_file_not_exist.stderr
@@ -7,11 +7,13 @@ LL | mod not_a_real_file;
    = help: to create the module `not_a_real_file`, create file "$DIR/not_a_real_file.rs" or "$DIR/not_a_real_file/mod.rs"
    = note: if there is a `mod not_a_real_file` elsewhere in the crate already, import it with `use crate::...` instead
 
-error[E0433]: failed to resolve: use of undeclared crate or module `mod_file_aux`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `mod_file_aux`
   --> $DIR/mod_file_not_exist.rs:7:16
    |
 LL |     assert_eq!(mod_file_aux::bar(), 10);
-   |                ^^^^^^^^^^^^ use of undeclared crate or module `mod_file_aux`
+   |                ^^^^^^^^^^^^ use of unresolved module or unlinked crate `mod_file_aux`
+   |
+   = help: you might be missing a crate named `mod_file_aux`
 
 error: aborting due to 2 previous errors
 
diff --git a/tests/ui/parser/mod_file_not_exist_windows.rs b/tests/ui/parser/mod_file_not_exist_windows.rs
index 88780c0c24e94..bb74684d99447 100644
--- a/tests/ui/parser/mod_file_not_exist_windows.rs
+++ b/tests/ui/parser/mod_file_not_exist_windows.rs
@@ -5,5 +5,6 @@ mod not_a_real_file; //~ ERROR file not found for module `not_a_real_file`
 
 fn main() {
     assert_eq!(mod_file_aux::bar(), 10);
-    //~^ ERROR failed to resolve: use of undeclared crate or module `mod_file_aux`
+    //~^ ERROR failed to resolve: use of unresolved module or unlinked crate `mod_file_aux`
+    //~| HELP you might be missing a crate named `mod_file_aux`
 }
diff --git a/tests/ui/parser/mod_file_not_exist_windows.stderr b/tests/ui/parser/mod_file_not_exist_windows.stderr
index 53b09d8ca53a0..03c762d0ef2dd 100644
--- a/tests/ui/parser/mod_file_not_exist_windows.stderr
+++ b/tests/ui/parser/mod_file_not_exist_windows.stderr
@@ -7,11 +7,13 @@ LL | mod not_a_real_file;
    = help: to create the module `not_a_real_file`, create file "$DIR/not_a_real_file.rs" or "$DIR/not_a_real_file/mod.rs"
    = note: if there is a `mod not_a_real_file` elsewhere in the crate already, import it with `use crate::...` instead
 
-error[E0433]: failed to resolve: use of undeclared crate or module `mod_file_aux`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `mod_file_aux`
   --> $DIR/mod_file_not_exist_windows.rs:7:16
    |
 LL |     assert_eq!(mod_file_aux::bar(), 10);
-   |                ^^^^^^^^^^^^ use of undeclared crate or module `mod_file_aux`
+   |                ^^^^^^^^^^^^ use of unresolved module or unlinked crate `mod_file_aux`
+   |
+   = help: you might be missing a crate named `mod_file_aux`
 
 error: aborting due to 2 previous errors
 
diff --git a/tests/ui/privacy/restricted/test.rs b/tests/ui/privacy/restricted/test.rs
index 3fdfd191b365b..b32b9327f07ee 100644
--- a/tests/ui/privacy/restricted/test.rs
+++ b/tests/ui/privacy/restricted/test.rs
@@ -47,6 +47,6 @@ fn main() {
 }
 
 mod pathological {
-    pub(in bad::path) mod m1 {} //~ ERROR failed to resolve: you might be missing crate `bad`
+    pub(in bad::path) mod m1 {} //~ ERROR failed to resolve: use of unresolved module or unlinked crate `bad`
     pub(in foo) mod m2 {} //~ ERROR visibilities can only be restricted to ancestor modules
 }
diff --git a/tests/ui/privacy/restricted/test.stderr b/tests/ui/privacy/restricted/test.stderr
index 5deaffbdbf3f8..2744b3708a826 100644
--- a/tests/ui/privacy/restricted/test.stderr
+++ b/tests/ui/privacy/restricted/test.stderr
@@ -1,10 +1,10 @@
-error[E0433]: failed to resolve: you might be missing crate `bad`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `bad`
   --> $DIR/test.rs:50:12
    |
 LL |     pub(in bad::path) mod m1 {}
-   |            ^^^ you might be missing crate `bad`
+   |            ^^^ use of unresolved module or unlinked crate `bad`
    |
-help: consider importing the `bad` crate
+help: you might be missing a crate named `bad`, add it to your project and import it in your code
    |
 LL + extern crate bad;
    |
diff --git a/tests/ui/resolve/112590-2.stderr b/tests/ui/resolve/112590-2.stderr
index 0db20249d27f5..b39b44396d730 100644
--- a/tests/ui/resolve/112590-2.stderr
+++ b/tests/ui/resolve/112590-2.stderr
@@ -14,12 +14,13 @@ LL -         let _: Vec<i32> = super::foo::baf::baz::MyVec::new();
 LL +         let _: Vec<i32> = MyVec::new();
    |
 
-error[E0433]: failed to resolve: use of undeclared crate or module `fox`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `fox`
   --> $DIR/112590-2.rs:18:27
    |
 LL |         let _: Vec<i32> = fox::bar::baz::MyVec::new();
-   |                           ^^^ use of undeclared crate or module `fox`
+   |                           ^^^ use of unresolved module or unlinked crate `fox`
    |
+   = help: you might be missing a crate named `fox`
 help: consider importing this struct through its public re-export
    |
 LL +     use foo::bar::baz::MyVec;
@@ -30,12 +31,13 @@ LL -         let _: Vec<i32> = fox::bar::baz::MyVec::new();
 LL +         let _: Vec<i32> = MyVec::new();
    |
 
-error[E0433]: failed to resolve: use of undeclared crate or module `vec`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `vec`
   --> $DIR/112590-2.rs:24:15
    |
 LL |     type _B = vec::Vec::<u8>;
-   |               ^^^ use of undeclared crate or module `vec`
+   |               ^^^ use of unresolved module or unlinked crate `vec`
    |
+   = help: you might be missing a crate named `vec`
 help: consider importing this module
    |
 LL + use std::vec;
@@ -57,14 +59,16 @@ LL -     let _t = std::sync_error::atomic::AtomicBool::new(true);
 LL +     let _t = AtomicBool::new(true);
    |
 
-error[E0433]: failed to resolve: use of undeclared crate or module `vec`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `vec`
   --> $DIR/112590-2.rs:23:24
    |
 LL |     let _t: Vec<i32> = vec::new();
    |                        ^^^
    |                        |
-   |                        use of undeclared crate or module `vec`
+   |                        use of unresolved module or unlinked crate `vec`
    |                        help: a struct with a similar name exists (notice the capitalization): `Vec`
+   |
+   = help: you might be missing a crate named `vec`
 
 error: aborting due to 5 previous errors
 
diff --git a/tests/ui/resolve/bad-module.rs b/tests/ui/resolve/bad-module.rs
index b23e97c2cf6bc..9fe06ab0f52ed 100644
--- a/tests/ui/resolve/bad-module.rs
+++ b/tests/ui/resolve/bad-module.rs
@@ -1,7 +1,7 @@
 fn main() {
     let foo = thing::len(Vec::new());
-    //~^ ERROR failed to resolve: use of undeclared crate or module `thing`
+    //~^ ERROR failed to resolve: use of unresolved module or unlinked crate `thing`
 
     let foo = foo::bar::baz();
-    //~^ ERROR failed to resolve: use of undeclared crate or module `foo`
+    //~^ ERROR failed to resolve: use of unresolved module or unlinked crate `foo`
 }
diff --git a/tests/ui/resolve/bad-module.stderr b/tests/ui/resolve/bad-module.stderr
index 558760c6793ab..0f597e126fdc5 100644
--- a/tests/ui/resolve/bad-module.stderr
+++ b/tests/ui/resolve/bad-module.stderr
@@ -1,14 +1,18 @@
-error[E0433]: failed to resolve: use of undeclared crate or module `foo`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `foo`
   --> $DIR/bad-module.rs:5:15
    |
 LL |     let foo = foo::bar::baz();
-   |               ^^^ use of undeclared crate or module `foo`
+   |               ^^^ use of unresolved module or unlinked crate `foo`
+   |
+   = help: you might be missing a crate named `foo`
 
-error[E0433]: failed to resolve: use of undeclared crate or module `thing`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `thing`
   --> $DIR/bad-module.rs:2:15
    |
 LL |     let foo = thing::len(Vec::new());
-   |               ^^^^^ use of undeclared crate or module `thing`
+   |               ^^^^^ use of unresolved module or unlinked crate `thing`
+   |
+   = help: you might be missing a crate named `thing`
 
 error: aborting due to 2 previous errors
 
diff --git a/tests/ui/resolve/editions-crate-root-2015.rs b/tests/ui/resolve/editions-crate-root-2015.rs
index 869f4c82c8b71..a2e19bfdf1c57 100644
--- a/tests/ui/resolve/editions-crate-root-2015.rs
+++ b/tests/ui/resolve/editions-crate-root-2015.rs
@@ -2,10 +2,10 @@
 
 mod inner {
     fn global_inner(_: ::nonexistant::Foo) {
-        //~^ ERROR failed to resolve: you might be missing crate `nonexistant`
+        //~^ ERROR failed to resolve: use of unresolved module or unlinked crate `nonexistant`
     }
     fn crate_inner(_: crate::nonexistant::Foo) {
-        //~^ ERROR failed to resolve: you might be missing crate `nonexistant`
+        //~^ ERROR failed to resolve: use of unresolved module or unlinked crate `nonexistant`
     }
 
     fn bare_global(_: ::nonexistant) {
diff --git a/tests/ui/resolve/editions-crate-root-2015.stderr b/tests/ui/resolve/editions-crate-root-2015.stderr
index 7a842aca0fd27..3d203c8ed9676 100644
--- a/tests/ui/resolve/editions-crate-root-2015.stderr
+++ b/tests/ui/resolve/editions-crate-root-2015.stderr
@@ -1,21 +1,21 @@
-error[E0433]: failed to resolve: you might be missing crate `nonexistant`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `nonexistant`
   --> $DIR/editions-crate-root-2015.rs:4:26
    |
 LL |     fn global_inner(_: ::nonexistant::Foo) {
-   |                          ^^^^^^^^^^^ you might be missing crate `nonexistant`
+   |                          ^^^^^^^^^^^ use of unresolved module or unlinked crate `nonexistant`
    |
-help: consider importing the `nonexistant` crate
+help: you might be missing a crate named `nonexistant`, add it to your project and import it in your code
    |
 LL + extern crate nonexistant;
    |
 
-error[E0433]: failed to resolve: you might be missing crate `nonexistant`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `nonexistant`
   --> $DIR/editions-crate-root-2015.rs:7:30
    |
 LL |     fn crate_inner(_: crate::nonexistant::Foo) {
-   |                              ^^^^^^^^^^^ you might be missing crate `nonexistant`
+   |                              ^^^^^^^^^^^ use of unresolved module or unlinked crate `nonexistant`
    |
-help: consider importing the `nonexistant` crate
+help: you might be missing a crate named `nonexistant`, add it to your project and import it in your code
    |
 LL + extern crate nonexistant;
    |
diff --git a/tests/ui/resolve/export-fully-qualified-2018.rs b/tests/ui/resolve/export-fully-qualified-2018.rs
index 26e3044d8df0e..ce78b64bf256d 100644
--- a/tests/ui/resolve/export-fully-qualified-2018.rs
+++ b/tests/ui/resolve/export-fully-qualified-2018.rs
@@ -5,7 +5,7 @@
 // want to change eventually.
 
 mod foo {
-    pub fn bar() { foo::baz(); } //~ ERROR failed to resolve: use of undeclared crate or module `foo`
+    pub fn bar() { foo::baz(); } //~ ERROR failed to resolve: use of unresolved module or unlinked crate `foo`
 
     fn baz() { }
 }
diff --git a/tests/ui/resolve/export-fully-qualified-2018.stderr b/tests/ui/resolve/export-fully-qualified-2018.stderr
index 378d9832a657a..a985669b8b415 100644
--- a/tests/ui/resolve/export-fully-qualified-2018.stderr
+++ b/tests/ui/resolve/export-fully-qualified-2018.stderr
@@ -1,8 +1,10 @@
-error[E0433]: failed to resolve: use of undeclared crate or module `foo`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `foo`
   --> $DIR/export-fully-qualified-2018.rs:8:20
    |
 LL |     pub fn bar() { foo::baz(); }
-   |                    ^^^ use of undeclared crate or module `foo`
+   |                    ^^^ use of unresolved module or unlinked crate `foo`
+   |
+   = help: you might be missing a crate named `foo`
 
 error: aborting due to 1 previous error
 
diff --git a/tests/ui/resolve/export-fully-qualified.rs b/tests/ui/resolve/export-fully-qualified.rs
index 6de33b7e1915f..0be3b81ebb8ff 100644
--- a/tests/ui/resolve/export-fully-qualified.rs
+++ b/tests/ui/resolve/export-fully-qualified.rs
@@ -5,7 +5,7 @@
 // want to change eventually.
 
 mod foo {
-    pub fn bar() { foo::baz(); } //~ ERROR failed to resolve: use of undeclared crate or module `foo`
+    pub fn bar() { foo::baz(); } //~ ERROR failed to resolve: use of unresolved module or unlinked crate `foo`
 
     fn baz() { }
 }
diff --git a/tests/ui/resolve/export-fully-qualified.stderr b/tests/ui/resolve/export-fully-qualified.stderr
index 869149d8d3c65..e65483e57eb57 100644
--- a/tests/ui/resolve/export-fully-qualified.stderr
+++ b/tests/ui/resolve/export-fully-qualified.stderr
@@ -1,8 +1,10 @@
-error[E0433]: failed to resolve: use of undeclared crate or module `foo`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `foo`
   --> $DIR/export-fully-qualified.rs:8:20
    |
 LL |     pub fn bar() { foo::baz(); }
-   |                    ^^^ use of undeclared crate or module `foo`
+   |                    ^^^ use of unresolved module or unlinked crate `foo`
+   |
+   = help: you might be missing a crate named `foo`
 
 error: aborting due to 1 previous error
 
diff --git a/tests/ui/resolve/extern-prelude-fail.stderr b/tests/ui/resolve/extern-prelude-fail.stderr
index 77c10f5f995bc..199a31244c067 100644
--- a/tests/ui/resolve/extern-prelude-fail.stderr
+++ b/tests/ui/resolve/extern-prelude-fail.stderr
@@ -2,20 +2,20 @@ error[E0432]: unresolved import `extern_prelude`
   --> $DIR/extern-prelude-fail.rs:7:9
    |
 LL |     use extern_prelude::S;
-   |         ^^^^^^^^^^^^^^ you might be missing crate `extern_prelude`
+   |         ^^^^^^^^^^^^^^ use of unresolved module or unlinked crate `extern_prelude`
    |
-help: consider importing the `extern_prelude` crate
+help: you might be missing a crate named `extern_prelude`, add it to your project and import it in your code
    |
 LL + extern crate extern_prelude;
    |
 
-error[E0433]: failed to resolve: you might be missing crate `extern_prelude`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `extern_prelude`
   --> $DIR/extern-prelude-fail.rs:8:15
    |
 LL |     let s = ::extern_prelude::S;
-   |               ^^^^^^^^^^^^^^ you might be missing crate `extern_prelude`
+   |               ^^^^^^^^^^^^^^ use of unresolved module or unlinked crate `extern_prelude`
    |
-help: consider importing the `extern_prelude` crate
+help: you might be missing a crate named `extern_prelude`, add it to your project and import it in your code
    |
 LL + extern crate extern_prelude;
    |
diff --git a/tests/ui/resolve/issue-101749-2.rs b/tests/ui/resolve/issue-101749-2.rs
index 4d3d469447c2b..636ff07c71ceb 100644
--- a/tests/ui/resolve/issue-101749-2.rs
+++ b/tests/ui/resolve/issue-101749-2.rs
@@ -12,5 +12,5 @@ fn main() {
     let rect = Rectangle::new(3, 4);
     // `area` is not implemented for `Rectangle`, so this should not suggest
     let _ = rect::area();
-    //~^ ERROR failed to resolve: use of undeclared crate or module `rect`
+    //~^ ERROR failed to resolve: use of unresolved module or unlinked crate `rect`
 }
diff --git a/tests/ui/resolve/issue-101749-2.stderr b/tests/ui/resolve/issue-101749-2.stderr
index 300aaf26cb7d8..96a20b4bf5a05 100644
--- a/tests/ui/resolve/issue-101749-2.stderr
+++ b/tests/ui/resolve/issue-101749-2.stderr
@@ -1,8 +1,10 @@
-error[E0433]: failed to resolve: use of undeclared crate or module `rect`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `rect`
   --> $DIR/issue-101749-2.rs:14:13
    |
 LL |     let _ = rect::area();
-   |             ^^^^ use of undeclared crate or module `rect`
+   |             ^^^^ use of unresolved module or unlinked crate `rect`
+   |
+   = help: you might be missing a crate named `rect`
 
 error: aborting due to 1 previous error
 
diff --git a/tests/ui/resolve/issue-101749.fixed b/tests/ui/resolve/issue-101749.fixed
index 97815793d298e..3244ad7a03139 100644
--- a/tests/ui/resolve/issue-101749.fixed
+++ b/tests/ui/resolve/issue-101749.fixed
@@ -15,5 +15,5 @@ impl Rectangle {
 fn main() {
     let rect = Rectangle::new(3, 4);
     let _ = rect.area();
-    //~^ ERROR failed to resolve: use of undeclared crate or module `rect`
+    //~^ ERROR failed to resolve: use of unresolved module or unlinked crate `rect`
 }
diff --git a/tests/ui/resolve/issue-101749.rs b/tests/ui/resolve/issue-101749.rs
index 994fc86778e08..c977df41d2f56 100644
--- a/tests/ui/resolve/issue-101749.rs
+++ b/tests/ui/resolve/issue-101749.rs
@@ -15,5 +15,5 @@ impl Rectangle {
 fn main() {
     let rect = Rectangle::new(3, 4);
     let _ = rect::area();
-    //~^ ERROR failed to resolve: use of undeclared crate or module `rect`
+    //~^ ERROR failed to resolve: use of unresolved module or unlinked crate `rect`
 }
diff --git a/tests/ui/resolve/issue-101749.stderr b/tests/ui/resolve/issue-101749.stderr
index 05515b1b46052..fedbf182ee8c2 100644
--- a/tests/ui/resolve/issue-101749.stderr
+++ b/tests/ui/resolve/issue-101749.stderr
@@ -1,9 +1,10 @@
-error[E0433]: failed to resolve: use of undeclared crate or module `rect`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `rect`
   --> $DIR/issue-101749.rs:17:13
    |
 LL |     let _ = rect::area();
-   |             ^^^^ use of undeclared crate or module `rect`
+   |             ^^^^ use of unresolved module or unlinked crate `rect`
    |
+   = help: you might be missing a crate named `rect`
 help: you may have meant to call an instance method
    |
 LL |     let _ = rect.area();
diff --git a/tests/ui/resolve/issue-82865.rs b/tests/ui/resolve/issue-82865.rs
index 29a898906e96b..4dc12f2f58956 100644
--- a/tests/ui/resolve/issue-82865.rs
+++ b/tests/ui/resolve/issue-82865.rs
@@ -2,7 +2,7 @@
 
 #![feature(decl_macro)]
 
-use x::y::z; //~ ERROR: failed to resolve: you might be missing crate `x`
+use x::y::z; //~ ERROR: failed to resolve: use of unresolved module or unlinked crate `x`
 
 macro mac () {
     Box::z //~ ERROR: no function or associated item
diff --git a/tests/ui/resolve/issue-82865.stderr b/tests/ui/resolve/issue-82865.stderr
index bc7e0f0798177..090085460b07b 100644
--- a/tests/ui/resolve/issue-82865.stderr
+++ b/tests/ui/resolve/issue-82865.stderr
@@ -1,10 +1,10 @@
-error[E0433]: failed to resolve: you might be missing crate `x`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `x`
   --> $DIR/issue-82865.rs:5:5
    |
 LL | use x::y::z;
-   |     ^ you might be missing crate `x`
+   |     ^ use of unresolved module or unlinked crate `x`
    |
-help: consider importing the `x` crate
+help: you might be missing a crate named `x`, add it to your project and import it in your code
    |
 LL + extern crate x;
    |
diff --git a/tests/ui/resolve/resolve-bad-visibility.stderr b/tests/ui/resolve/resolve-bad-visibility.stderr
index 281e5afb22302..ac7e1c735b1f9 100644
--- a/tests/ui/resolve/resolve-bad-visibility.stderr
+++ b/tests/ui/resolve/resolve-bad-visibility.stderr
@@ -16,24 +16,24 @@ error[E0742]: visibilities can only be restricted to ancestor modules
 LL | pub(in std::vec) struct F;
    |        ^^^^^^^^
 
-error[E0433]: failed to resolve: you might be missing crate `nonexistent`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `nonexistent`
   --> $DIR/resolve-bad-visibility.rs:7:8
    |
 LL | pub(in nonexistent) struct G;
-   |        ^^^^^^^^^^^ you might be missing crate `nonexistent`
+   |        ^^^^^^^^^^^ use of unresolved module or unlinked crate `nonexistent`
    |
-help: consider importing the `nonexistent` crate
+help: you might be missing a crate named `nonexistent`, add it to your project and import it in your code
    |
 LL + extern crate nonexistent;
    |
 
-error[E0433]: failed to resolve: you might be missing crate `too_soon`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `too_soon`
   --> $DIR/resolve-bad-visibility.rs:8:8
    |
 LL | pub(in too_soon) struct H;
-   |        ^^^^^^^^ you might be missing crate `too_soon`
+   |        ^^^^^^^^ use of unresolved module or unlinked crate `too_soon`
    |
-help: consider importing the `too_soon` crate
+help: you might be missing a crate named `too_soon`, add it to your project and import it in your code
    |
 LL + extern crate too_soon;
    |
diff --git a/tests/ui/resolve/typo-suggestion-mistyped-in-path.rs b/tests/ui/resolve/typo-suggestion-mistyped-in-path.rs
index 3ce17a14f146b..188e2ca7f1133 100644
--- a/tests/ui/resolve/typo-suggestion-mistyped-in-path.rs
+++ b/tests/ui/resolve/typo-suggestion-mistyped-in-path.rs
@@ -29,8 +29,8 @@ fn main() {
     //~| NOTE use of undeclared type `Struc`
 
     modul::foo();
-    //~^ ERROR failed to resolve: use of undeclared crate or module `modul`
-    //~| NOTE use of undeclared crate or module `modul`
+    //~^ ERROR failed to resolve: use of unresolved module or unlinked crate `modul`
+    //~| NOTE use of unresolved module or unlinked crate `modul`
 
     module::Struc::foo();
     //~^ ERROR failed to resolve: could not find `Struc` in `module`
diff --git a/tests/ui/resolve/typo-suggestion-mistyped-in-path.stderr b/tests/ui/resolve/typo-suggestion-mistyped-in-path.stderr
index f4fb7fd955f2b..3ae134e43bc18 100644
--- a/tests/ui/resolve/typo-suggestion-mistyped-in-path.stderr
+++ b/tests/ui/resolve/typo-suggestion-mistyped-in-path.stderr
@@ -30,11 +30,11 @@ LL |     Struc::foo();
    |     use of undeclared type `Struc`
    |     help: a struct with a similar name exists: `Struct`
 
-error[E0433]: failed to resolve: use of undeclared crate or module `modul`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `modul`
   --> $DIR/typo-suggestion-mistyped-in-path.rs:31:5
    |
 LL |     modul::foo();
-   |     ^^^^^ use of undeclared crate or module `modul`
+   |     ^^^^^ use of unresolved module or unlinked crate `modul`
    |
 help: there is a crate or module with a similar name
    |
diff --git a/tests/ui/rfcs/rfc-2126-extern-absolute-paths/non-existent-1.stderr b/tests/ui/rfcs/rfc-2126-extern-absolute-paths/non-existent-1.stderr
index 1047dbe1063e8..106268ac2c7ae 100644
--- a/tests/ui/rfcs/rfc-2126-extern-absolute-paths/non-existent-1.stderr
+++ b/tests/ui/rfcs/rfc-2126-extern-absolute-paths/non-existent-1.stderr
@@ -2,7 +2,9 @@ error[E0432]: unresolved import `xcrate`
   --> $DIR/non-existent-1.rs:3:5
    |
 LL | use xcrate::S;
-   |     ^^^^^^ use of undeclared crate or module `xcrate`
+   |     ^^^^^^ use of unresolved module or unlinked crate `xcrate`
+   |
+   = help: you might be missing a crate named `xcrate`
 
 error: aborting due to 1 previous error
 
diff --git a/tests/ui/rust-2018/unresolved-asterisk-imports.stderr b/tests/ui/rust-2018/unresolved-asterisk-imports.stderr
index b6bf109824f70..049d52893d4b7 100644
--- a/tests/ui/rust-2018/unresolved-asterisk-imports.stderr
+++ b/tests/ui/rust-2018/unresolved-asterisk-imports.stderr
@@ -2,7 +2,9 @@ error[E0432]: unresolved import `not_existing_crate`
   --> $DIR/unresolved-asterisk-imports.rs:3:5
    |
 LL | use not_existing_crate::*;
-   |     ^^^^^^^^^^^^^^^^^^ use of undeclared crate or module `not_existing_crate`
+   |     ^^^^^^^^^^^^^^^^^^ use of unresolved module or unlinked crate `not_existing_crate`
+   |
+   = help: you might be missing a crate named `not_existing_crate`
 
 error: aborting due to 1 previous error
 
diff --git a/tests/ui/suggestions/crate-or-module-typo.rs b/tests/ui/suggestions/crate-or-module-typo.rs
index dbc0605c76bce..393fc7a1f72e0 100644
--- a/tests/ui/suggestions/crate-or-module-typo.rs
+++ b/tests/ui/suggestions/crate-or-module-typo.rs
@@ -1,6 +1,6 @@
 //@ edition:2018
 
-use st::cell::Cell; //~ ERROR failed to resolve: use of undeclared crate or module `st`
+use st::cell::Cell; //~ ERROR failed to resolve: use of unresolved module or unlinked crate `st`
 
 mod bar {
     pub fn bar() { bar::baz(); } //~ ERROR failed to resolve: function `bar` is not a crate or module
@@ -11,7 +11,7 @@ mod bar {
 use bas::bar; //~ ERROR unresolved import `bas`
 
 struct Foo {
-    bar: st::cell::Cell<bool> //~ ERROR failed to resolve: use of undeclared crate or module `st`
+    bar: st::cell::Cell<bool> //~ ERROR failed to resolve: use of unresolved module or unlinked crate `st`
 }
 
 fn main() {}
diff --git a/tests/ui/suggestions/crate-or-module-typo.stderr b/tests/ui/suggestions/crate-or-module-typo.stderr
index 084d0408a8e7d..75aa6e614b648 100644
--- a/tests/ui/suggestions/crate-or-module-typo.stderr
+++ b/tests/ui/suggestions/crate-or-module-typo.stderr
@@ -1,8 +1,8 @@
-error[E0433]: failed to resolve: use of undeclared crate or module `st`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `st`
   --> $DIR/crate-or-module-typo.rs:3:5
    |
 LL | use st::cell::Cell;
-   |     ^^ use of undeclared crate or module `st`
+   |     ^^ use of unresolved module or unlinked crate `st`
    |
 help: there is a crate or module with a similar name
    |
@@ -13,18 +13,18 @@ error[E0432]: unresolved import `bas`
   --> $DIR/crate-or-module-typo.rs:11:5
    |
 LL | use bas::bar;
-   |     ^^^ use of undeclared crate or module `bas`
+   |     ^^^ use of unresolved module or unlinked crate `bas`
    |
 help: there is a crate or module with a similar name
    |
 LL | use bar::bar;
    |     ~~~
 
-error[E0433]: failed to resolve: use of undeclared crate or module `st`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `st`
   --> $DIR/crate-or-module-typo.rs:14:10
    |
 LL |     bar: st::cell::Cell<bool>
-   |          ^^ use of undeclared crate or module `st`
+   |          ^^ use of unresolved module or unlinked crate `st`
    |
 help: there is a crate or module with a similar name
    |
diff --git a/tests/ui/suggestions/issue-112590-suggest-import.rs b/tests/ui/suggestions/issue-112590-suggest-import.rs
index 0938814c55985..a7868b719190f 100644
--- a/tests/ui/suggestions/issue-112590-suggest-import.rs
+++ b/tests/ui/suggestions/issue-112590-suggest-import.rs
@@ -1,8 +1,8 @@
 pub struct S;
 
-impl fmt::Debug for S { //~ ERROR failed to resolve: use of undeclared crate or module `fmt`
-    fn fmt(&self, _f: &mut fmt::Formatter<'_>) -> fmt::Result { //~ ERROR failed to resolve: use of undeclared crate or module `fmt`
-        //~^ ERROR failed to resolve: use of undeclared crate or module `fmt`
+impl fmt::Debug for S { //~ ERROR failed to resolve: use of unresolved module or unlinked crate `fmt`
+    fn fmt(&self, _f: &mut fmt::Formatter<'_>) -> fmt::Result { //~ ERROR failed to resolve: use of unresolved module or unlinked crate `fmt`
+        //~^ ERROR failed to resolve: use of unresolved module or unlinked crate `fmt`
         Ok(())
     }
 }
diff --git a/tests/ui/suggestions/issue-112590-suggest-import.stderr b/tests/ui/suggestions/issue-112590-suggest-import.stderr
index aeac18c16f047..bbbd2c481c1cf 100644
--- a/tests/ui/suggestions/issue-112590-suggest-import.stderr
+++ b/tests/ui/suggestions/issue-112590-suggest-import.stderr
@@ -1,31 +1,34 @@
-error[E0433]: failed to resolve: use of undeclared crate or module `fmt`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `fmt`
   --> $DIR/issue-112590-suggest-import.rs:3:6
    |
 LL | impl fmt::Debug for S {
-   |      ^^^ use of undeclared crate or module `fmt`
+   |      ^^^ use of unresolved module or unlinked crate `fmt`
    |
+   = help: you might be missing a crate named `fmt`
 help: consider importing this module
    |
 LL + use std::fmt;
    |
 
-error[E0433]: failed to resolve: use of undeclared crate or module `fmt`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `fmt`
   --> $DIR/issue-112590-suggest-import.rs:4:28
    |
 LL |     fn fmt(&self, _f: &mut fmt::Formatter<'_>) -> fmt::Result {
-   |                            ^^^ use of undeclared crate or module `fmt`
+   |                            ^^^ use of unresolved module or unlinked crate `fmt`
    |
+   = help: you might be missing a crate named `fmt`
 help: consider importing this module
    |
 LL + use std::fmt;
    |
 
-error[E0433]: failed to resolve: use of undeclared crate or module `fmt`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `fmt`
   --> $DIR/issue-112590-suggest-import.rs:4:51
    |
 LL |     fn fmt(&self, _f: &mut fmt::Formatter<'_>) -> fmt::Result {
-   |                                                   ^^^ use of undeclared crate or module `fmt`
+   |                                                   ^^^ use of unresolved module or unlinked crate `fmt`
    |
+   = help: you might be missing a crate named `fmt`
 help: consider importing this module
    |
 LL + use std::fmt;
diff --git a/tests/ui/suggestions/undeclared-module-alloc.rs b/tests/ui/suggestions/undeclared-module-alloc.rs
index e5f22369b941a..a0bddc94471c1 100644
--- a/tests/ui/suggestions/undeclared-module-alloc.rs
+++ b/tests/ui/suggestions/undeclared-module-alloc.rs
@@ -1,5 +1,5 @@
 //@ edition:2018
 
-use alloc::rc::Rc; //~ ERROR failed to resolve: use of undeclared crate or module `alloc`
+use alloc::rc::Rc; //~ ERROR failed to resolve: use of unresolved module or unlinked crate `alloc`
 
 fn main() {}
diff --git a/tests/ui/suggestions/undeclared-module-alloc.stderr b/tests/ui/suggestions/undeclared-module-alloc.stderr
index a439546492b5f..00e498aa9ba9d 100644
--- a/tests/ui/suggestions/undeclared-module-alloc.stderr
+++ b/tests/ui/suggestions/undeclared-module-alloc.stderr
@@ -1,8 +1,8 @@
-error[E0433]: failed to resolve: use of undeclared crate or module `alloc`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `alloc`
   --> $DIR/undeclared-module-alloc.rs:3:5
    |
 LL | use alloc::rc::Rc;
-   |     ^^^^^ use of undeclared crate or module `alloc`
+   |     ^^^^^ use of unresolved module or unlinked crate `alloc`
    |
    = help: add `extern crate alloc` to use the `alloc` crate
 
diff --git a/tests/ui/tool-attributes/unknown-tool-name.rs b/tests/ui/tool-attributes/unknown-tool-name.rs
index 73fca61c65d1b..ba21aecc230a8 100644
--- a/tests/ui/tool-attributes/unknown-tool-name.rs
+++ b/tests/ui/tool-attributes/unknown-tool-name.rs
@@ -1,2 +1,2 @@
-#[foo::bar] //~ ERROR failed to resolve: use of undeclared crate or module `foo`
+#[foo::bar] //~ ERROR failed to resolve: use of unresolved module or unlinked crate `foo`
 fn main() {}
diff --git a/tests/ui/tool-attributes/unknown-tool-name.stderr b/tests/ui/tool-attributes/unknown-tool-name.stderr
index 361d359a10e47..9b636fcb0bdd7 100644
--- a/tests/ui/tool-attributes/unknown-tool-name.stderr
+++ b/tests/ui/tool-attributes/unknown-tool-name.stderr
@@ -1,8 +1,8 @@
-error[E0433]: failed to resolve: use of undeclared crate or module `foo`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `foo`
   --> $DIR/unknown-tool-name.rs:1:3
    |
 LL | #[foo::bar]
-   |   ^^^ use of undeclared crate or module `foo`
+   |   ^^^ use of unresolved module or unlinked crate `foo`
 
 error: aborting due to 1 previous error
 
diff --git a/tests/ui/typeck/issue-120856.rs b/tests/ui/typeck/issue-120856.rs
index e435a0f9d8e89..51dd63a6f89da 100644
--- a/tests/ui/typeck/issue-120856.rs
+++ b/tests/ui/typeck/issue-120856.rs
@@ -1,5 +1,5 @@
 pub type Archived<T> = <m::Alias as n::Trait>::Archived;
-//~^ ERROR failed to resolve: use of undeclared crate or module `m`
-//~| ERROR failed to resolve: use of undeclared crate or module `n`
+//~^ ERROR failed to resolve: use of unresolved module or unlinked crate `m`
+//~| ERROR failed to resolve: use of unresolved module or unlinked crate `n`
 
 fn main() {}
diff --git a/tests/ui/typeck/issue-120856.stderr b/tests/ui/typeck/issue-120856.stderr
index 1fc8b20047355..e366744409f4e 100644
--- a/tests/ui/typeck/issue-120856.stderr
+++ b/tests/ui/typeck/issue-120856.stderr
@@ -1,20 +1,24 @@
-error[E0433]: failed to resolve: use of undeclared crate or module `n`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `n`
   --> $DIR/issue-120856.rs:1:37
    |
 LL | pub type Archived<T> = <m::Alias as n::Trait>::Archived;
    |                                     ^
    |                                     |
-   |                                     use of undeclared crate or module `n`
+   |                                     use of unresolved module or unlinked crate `n`
    |                                     help: a trait with a similar name exists: `Fn`
+   |
+   = help: you might be missing a crate named `n`
 
-error[E0433]: failed to resolve: use of undeclared crate or module `m`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `m`
   --> $DIR/issue-120856.rs:1:25
    |
 LL | pub type Archived<T> = <m::Alias as n::Trait>::Archived;
    |                         ^
    |                         |
-   |                         use of undeclared crate or module `m`
+   |                         use of unresolved module or unlinked crate `m`
    |                         help: a type parameter with a similar name exists: `T`
+   |
+   = help: you might be missing a crate named `m`
 
 error: aborting due to 2 previous errors
 
diff --git a/tests/ui/typeck/path-to-method-sugg-unresolved-expr.cargo-invoked.stderr b/tests/ui/typeck/path-to-method-sugg-unresolved-expr.cargo-invoked.stderr
new file mode 100644
index 0000000000000..8a3b87b0d11a5
--- /dev/null
+++ b/tests/ui/typeck/path-to-method-sugg-unresolved-expr.cargo-invoked.stderr
@@ -0,0 +1,11 @@
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `page_size`
+  --> $DIR/path-to-method-sugg-unresolved-expr.rs:5:21
+   |
+LL |     let page_size = page_size::get();
+   |                     ^^^^^^^^^ use of unresolved module or unlinked crate `page_size`
+   |
+   = help: if you wanted to use a crate named `page_size`, use `cargo add page_size` to add it to your `Cargo.toml`
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0433`.
diff --git a/tests/ui/typeck/path-to-method-sugg-unresolved-expr.only-rustc.stderr b/tests/ui/typeck/path-to-method-sugg-unresolved-expr.only-rustc.stderr
new file mode 100644
index 0000000000000..34ed5c44d9313
--- /dev/null
+++ b/tests/ui/typeck/path-to-method-sugg-unresolved-expr.only-rustc.stderr
@@ -0,0 +1,11 @@
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `page_size`
+  --> $DIR/path-to-method-sugg-unresolved-expr.rs:5:21
+   |
+LL |     let page_size = page_size::get();
+   |                     ^^^^^^^^^ use of unresolved module or unlinked crate `page_size`
+   |
+   = help: you might be missing a crate named `page_size`
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0433`.
diff --git a/tests/ui/typeck/path-to-method-sugg-unresolved-expr.rs b/tests/ui/typeck/path-to-method-sugg-unresolved-expr.rs
index fb56b394493dc..7b4f62fea0c81 100644
--- a/tests/ui/typeck/path-to-method-sugg-unresolved-expr.rs
+++ b/tests/ui/typeck/path-to-method-sugg-unresolved-expr.rs
@@ -1,4 +1,10 @@
+//@ revisions: only-rustc cargo-invoked
+//@[only-rustc] unset-rustc-env:CARGO_CRATE_NAME
+//@[cargo-invoked] rustc-env:CARGO_CRATE_NAME=foo
 fn main() {
     let page_size = page_size::get();
-    //~^ ERROR failed to resolve: use of undeclared crate or module `page_size`
+    //~^ ERROR failed to resolve: use of unresolved module or unlinked crate `page_size`
+    //~| NOTE use of unresolved module or unlinked crate `page_size`
+    //@[cargo-invoked]~^^^ HELP if you wanted to use a crate named `page_size`, use `cargo add
+    //@[only-rustc]~^^^^ HELP you might be missing a crate named `page_size`
 }
diff --git a/tests/ui/typeck/path-to-method-sugg-unresolved-expr.stderr b/tests/ui/typeck/path-to-method-sugg-unresolved-expr.stderr
deleted file mode 100644
index 3e03c17f3b1c3..0000000000000
--- a/tests/ui/typeck/path-to-method-sugg-unresolved-expr.stderr
+++ /dev/null
@@ -1,9 +0,0 @@
-error[E0433]: failed to resolve: use of undeclared crate or module `page_size`
-  --> $DIR/path-to-method-sugg-unresolved-expr.rs:2:21
-   |
-LL |     let page_size = page_size::get();
-   |                     ^^^^^^^^^ use of undeclared crate or module `page_size`
-
-error: aborting due to 1 previous error
-
-For more information about this error, try `rustc --explain E0433`.
diff --git a/tests/ui/unresolved/unresolved-asterisk-imports.stderr b/tests/ui/unresolved/unresolved-asterisk-imports.stderr
index ed01f3fdbea41..e84f1975112b0 100644
--- a/tests/ui/unresolved/unresolved-asterisk-imports.stderr
+++ b/tests/ui/unresolved/unresolved-asterisk-imports.stderr
@@ -2,9 +2,9 @@ error[E0432]: unresolved import `not_existing_crate`
   --> $DIR/unresolved-asterisk-imports.rs:1:5
    |
 LL | use not_existing_crate::*;
-   |     ^^^^^^^^^^^^^^^^^^ you might be missing crate `not_existing_crate`
+   |     ^^^^^^^^^^^^^^^^^^ use of unresolved module or unlinked crate `not_existing_crate`
    |
-help: consider importing the `not_existing_crate` crate
+help: you might be missing a crate named `not_existing_crate`, add it to your project and import it in your code
    |
 LL + extern crate not_existing_crate;
    |
diff --git a/tests/ui/unresolved/unresolved-import.rs b/tests/ui/unresolved/unresolved-import.rs
index ee520d65e6f4a..763e9496734dd 100644
--- a/tests/ui/unresolved/unresolved-import.rs
+++ b/tests/ui/unresolved/unresolved-import.rs
@@ -1,7 +1,7 @@
 use foo::bar;
 //~^ ERROR unresolved import `foo` [E0432]
-//~| NOTE you might be missing crate `foo`
-//~| HELP consider importing the `foo` crate
+//~| NOTE use of unresolved module or unlinked crate `foo`
+//~| HELP you might be missing a crate named `foo`
 //~| SUGGESTION extern crate foo;
 
 use bar::Baz as x;
diff --git a/tests/ui/unresolved/unresolved-import.stderr b/tests/ui/unresolved/unresolved-import.stderr
index a1ff2f19eb640..c65fe841001d7 100644
--- a/tests/ui/unresolved/unresolved-import.stderr
+++ b/tests/ui/unresolved/unresolved-import.stderr
@@ -2,9 +2,9 @@ error[E0432]: unresolved import `foo`
   --> $DIR/unresolved-import.rs:1:5
    |
 LL | use foo::bar;
-   |     ^^^ you might be missing crate `foo`
+   |     ^^^ use of unresolved module or unlinked crate `foo`
    |
-help: consider importing the `foo` crate
+help: you might be missing a crate named `foo`, add it to your project and import it in your code
    |
 LL + extern crate foo;
    |

From 7c885c104d7260d625bc54cdad615e74710e2376 Mon Sep 17 00:00:00 2001
From: jyn <github@jyn.dev>
Date: Sun, 19 Jan 2025 08:54:28 -0500
Subject: [PATCH 14/17] Compare object files, not PATH

PATH is never printed on Windows.
---
 tests/run-make/linker-warning/rmake.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tests/run-make/linker-warning/rmake.rs b/tests/run-make/linker-warning/rmake.rs
index f1a97af75d8af..3936d68276e16 100644
--- a/tests/run-make/linker-warning/rmake.rs
+++ b/tests/run-make/linker-warning/rmake.rs
@@ -25,14 +25,14 @@ fn main() {
     let out = run_rustc().link_arg("run_make_error").verbose().run_fail();
     out.assert_stderr_contains_regex("fake-linker.*run_make_error")
         .assert_stderr_not_contains("object files omitted")
-        .assert_stderr_contains("PATH=\"")
+        .assert_stderr_contains(r".rcgu.o")
         .assert_stderr_contains_regex(r"lib(/|\\\\)libstd");
 
     let out = run_rustc().link_arg("run_make_error").run_fail();
     out.assert_stderr_contains("fake-linker")
         .assert_stderr_contains("object files omitted")
         .assert_stderr_contains_regex(r"\{")
-        .assert_stderr_not_contains("PATH=\"")
+        .assert_stderr_not_contains(r".rcgu.o")
         .assert_stderr_not_contains_regex(r"lib(/|\\\\)libstd");
 
     // FIXME: we should have a version of this for mac and windows

From 7786f7f38842d705f1d031c5ba08b10ef5638927 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E8=AE=B8=E6=9D=B0=E5=8F=8B=20Jieyou=20Xu=20=28Joe=29?=
 <39484203+jieyouxu@users.noreply.github.com>
Date: Tue, 21 Jan 2025 21:01:49 +0800
Subject: [PATCH 15/17] run-make-support: add `sysroot` helper

Convenience helper for `rustc --print=sysroot`.
---
 src/tools/run-make-support/src/external_deps/rustc.rs | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/tools/run-make-support/src/external_deps/rustc.rs b/src/tools/run-make-support/src/external_deps/rustc.rs
index 8894ea7fb209b..b70db7130f677 100644
--- a/src/tools/run-make-support/src/external_deps/rustc.rs
+++ b/src/tools/run-make-support/src/external_deps/rustc.rs
@@ -1,5 +1,6 @@
 use std::ffi::{OsStr, OsString};
-use std::path::Path;
+use std::path::{Path, PathBuf};
+use std::str::FromStr as _;
 
 use crate::command::Command;
 use crate::env::env_var;
@@ -390,3 +391,10 @@ impl Rustc {
         self
     }
 }
+
+/// Query the sysroot path corresponding `rustc --print=sysroot`.
+#[track_caller]
+pub fn sysroot() -> PathBuf {
+    let path = rustc().print("sysroot").run().stdout_utf8();
+    PathBuf::from_str(path.trim()).unwrap()
+}

From 1912d565a8c6aa6ebe82b7fc753b07a89ff2b664 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E8=AE=B8=E6=9D=B0=E5=8F=8B=20Jieyou=20Xu=20=28Joe=29?=
 <39484203+jieyouxu@users.noreply.github.com>
Date: Wed, 22 Jan 2025 16:03:21 +0800
Subject: [PATCH 16/17] run-make-support: improve docs for `assert_exit_code`

---
 src/tools/run-make-support/src/command.rs | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/tools/run-make-support/src/command.rs b/src/tools/run-make-support/src/command.rs
index b4dc753ab5347..c31e79e167389 100644
--- a/src/tools/run-make-support/src/command.rs
+++ b/src/tools/run-make-support/src/command.rs
@@ -388,9 +388,15 @@ impl CompletedProcess {
         self
     }
 
+    /// Check the **exit status** of the process. On Unix, this is *not* the **wait status**.
+    ///
+    /// See [`std::process::ExitStatus::code`]. This is not to be confused with
+    /// [`std::process::ExitCode`].
     #[track_caller]
     pub fn assert_exit_code(&self, code: i32) -> &Self {
-        assert!(self.output.status.code() == Some(code));
+        // FIXME(jieyouxu): this should really be named `exit_status`, because std has an `ExitCode`
+        // that means a different thing.
+        assert_eq!(self.output.status.code(), Some(code));
         self
     }
 }

From 388a52f55151186731eec45f52a3786112ee3dcc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E8=AE=B8=E6=9D=B0=E5=8F=8B=20Jieyou=20Xu=20=28Joe=29?=
 <39484203+jieyouxu@users.noreply.github.com>
Date: Tue, 21 Jan 2025 21:03:18 +0800
Subject: [PATCH 17/17] tests: port `translation` to rmake.rs

Co-authored-by: Oneirical <manchot@videotron.ca>
---
 .../tidy/src/allowed_run_make_makefiles.txt   |   1 -
 tests/run-make/translation/Makefile           |  78 --------
 tests/run-make/translation/rmake.rs           | 174 ++++++++++++++++++
 3 files changed, 174 insertions(+), 79 deletions(-)
 delete mode 100644 tests/run-make/translation/Makefile
 create mode 100644 tests/run-make/translation/rmake.rs

diff --git a/src/tools/tidy/src/allowed_run_make_makefiles.txt b/src/tools/tidy/src/allowed_run_make_makefiles.txt
index 6f0fd09b353a5..e75d3dc2147bc 100644
--- a/src/tools/tidy/src/allowed_run_make_makefiles.txt
+++ b/src/tools/tidy/src/allowed_run_make_makefiles.txt
@@ -1,3 +1,2 @@
 run-make/split-debuginfo/Makefile
 run-make/symbol-mangling-hashed/Makefile
-run-make/translation/Makefile
diff --git a/tests/run-make/translation/Makefile b/tests/run-make/translation/Makefile
deleted file mode 100644
index 07e0547cfa090..0000000000000
--- a/tests/run-make/translation/Makefile
+++ /dev/null
@@ -1,78 +0,0 @@
-include ../tools.mk
-
-# This test uses `ln -s` rather than copying to save testing time, but its
-# usage doesn't work on Windows.
-# ignore-windows
-
-SYSROOT:=$(shell $(RUSTC) --print sysroot)
-FAKEROOT=$(TMPDIR)/fakeroot
-RUSTC_LOG:=rustc_error_messages
-export RUSTC_TRANSLATION_NO_DEBUG_ASSERT:=1
-
-all: normal custom missing broken sysroot sysroot-invalid sysroot-missing
-
-# Check that the test works normally, using the built-in fallback bundle.
-normal: test.rs
-	$(RUSTC) $< 2>&1 | $(CGREP) "struct literal body without path"
-
-# Check that a primary bundle can be loaded and will be preferentially used
-# where possible.
-custom: test.rs working.ftl
-	$(RUSTC) $< -Ztranslate-additional-ftl=$(CURDIR)/working.ftl 2>&1 | $(CGREP) "this is a test message"
-
-# Check that a primary bundle with a broken message (e.g. a interpolated
-# variable is missing) will use the fallback bundle.
-missing: test.rs missing.ftl
-	$(RUSTC) $< -Ztranslate-additional-ftl=$(CURDIR)/missing.ftl 2>&1 | $(CGREP) "struct literal body without path"
-
-# Check that a primary bundle without the desired message will use the fallback
-# bundle.
-broken: test.rs broken.ftl
-	$(RUSTC) $< -Ztranslate-additional-ftl=$(CURDIR)/broken.ftl 2>&1 | $(CGREP) "struct literal body without path"
-
-# Check that a locale can be loaded from the sysroot given a language
-# identifier by making a local copy of the sysroot and adding the custom locale
-# to it.
-sysroot: test.rs working.ftl
-	rm -rf $(FAKEROOT)
-	mkdir $(FAKEROOT)
-	ln -s $(SYSROOT)/* $(FAKEROOT)
-	rm -f $(FAKEROOT)/lib
-	mkdir $(FAKEROOT)/lib
-	ln -s $(SYSROOT)/lib/* $(FAKEROOT)/lib
-	rm -f $(FAKEROOT)/lib/rustlib
-	mkdir $(FAKEROOT)/lib/rustlib
-	ln -s $(SYSROOT)/lib/rustlib/* $(FAKEROOT)/lib/rustlib
-	rm -f $(FAKEROOT)/lib/rustlib/src
-	mkdir $(FAKEROOT)/lib/rustlib/src
-	ln -s $(SYSROOT)/lib/rustlib/src/* $(FAKEROOT)/lib/rustlib/src
-	# When download-rustc is enabled, `$(SYSROOT)` will have a share directory. Delete the link to it.
-	rm -f $(FAKEROOT)/share
-	mkdir -p $(FAKEROOT)/share/locale/zh-CN/
-	ln -s $(CURDIR)/working.ftl $(FAKEROOT)/share/locale/zh-CN/basic-translation.ftl
-	$(RUSTC) $< --sysroot $(FAKEROOT) -Ztranslate-lang=zh-CN 2>&1 | $(CGREP) "this is a test message"
-
-# Check that the compiler errors out when the sysroot requested cannot be
-# found. This test might start failing if there actually exists a Klingon
-# translation of rustc's error messages.
-sysroot-missing:
-	$(RUSTC) $< -Ztranslate-lang=tlh 2>&1 | $(CGREP) "missing locale directory"
-
-# Check that the compiler errors out when the directory for the locale in the
-# sysroot is actually a file.
-sysroot-invalid: test.rs working.ftl
-	rm -rf $(FAKEROOT)
-	mkdir $(FAKEROOT)
-	ln -s $(SYSROOT)/* $(FAKEROOT)
-	rm -f $(FAKEROOT)/lib
-	mkdir $(FAKEROOT)/lib
-	ln -s $(SYSROOT)/lib/* $(FAKEROOT)/lib
-	rm -f $(FAKEROOT)/lib/rustlib
-	mkdir $(FAKEROOT)/lib/rustlib
-	ln -s $(SYSROOT)/lib/rustlib/* $(FAKEROOT)/lib/rustlib
-	rm -f $(FAKEROOT)/lib/rustlib/src
-	mkdir $(FAKEROOT)/lib/rustlib/src
-	ln -s $(SYSROOT)/lib/rustlib/src/* $(FAKEROOT)/lib/rustlib/src
-	mkdir -p $(FAKEROOT)/share/locale
-	touch $(FAKEROOT)/share/locale/zh-CN
-	$(RUSTC) $< --sysroot $(FAKEROOT) -Ztranslate-lang=zh-CN 2>&1 | $(CGREP) "`\$sysroot/share/locales/\$locale` is not a directory"
diff --git a/tests/run-make/translation/rmake.rs b/tests/run-make/translation/rmake.rs
new file mode 100644
index 0000000000000..79b9c0dd67896
--- /dev/null
+++ b/tests/run-make/translation/rmake.rs
@@ -0,0 +1,174 @@
+//! Smoke test for the rustc diagnostics translation infrastructure.
+//!
+//! # References
+//!
+//! - Current tracking issue: <https://github.com/rust-lang/rust/issues/132181>.
+//! - Old tracking issue: <https://github.com/rust-lang/rust/issues/100717>
+//! - Initial translation infra implementation: <https://github.com/rust-lang/rust/pull/95512>.
+
+// This test uses symbolic links to stub out a fake sysroot to save testing time.
+//@ needs-symlink
+//@ needs-subprocess
+
+#![deny(warnings)]
+
+use std::path::{Path, PathBuf};
+
+use run_make_support::rustc::sysroot;
+use run_make_support::{cwd, rfs, run_in_tmpdir, rustc};
+
+fn main() {
+    builtin_fallback_bundle();
+    additional_primary_bundle();
+    missing_slug_prefers_fallback_bundle();
+    broken_primary_bundle_prefers_fallback_bundle();
+    locale_sysroot();
+    missing_sysroot();
+    file_sysroot();
+}
+
+/// Check that the test works normally, using the built-in fallback bundle.
+fn builtin_fallback_bundle() {
+    rustc().input("test.rs").run_fail().assert_stderr_contains("struct literal body without path");
+}
+
+/// Check that a primary bundle can be loaded and will be preferentially used where possible.
+fn additional_primary_bundle() {
+    rustc()
+        .input("test.rs")
+        .arg("-Ztranslate-additional-ftl=working.ftl")
+        .run_fail()
+        .assert_stderr_contains("this is a test message");
+}
+
+/// Check that a primary bundle without the desired message will use the fallback bundle.
+fn missing_slug_prefers_fallback_bundle() {
+    rustc()
+        .input("test.rs")
+        .arg("-Ztranslate-additional-ftl=missing.ftl")
+        .run_fail()
+        .assert_stderr_contains("struct literal body without path");
+}
+
+/// Check that a primary bundle with a broken message (e.g. an interpolated variable is not
+/// provided) will use the fallback bundle.
+fn broken_primary_bundle_prefers_fallback_bundle() {
+    // FIXME(#135817): as of the rmake.rs port, the compiler actually ICEs on the additional
+    // `broken.ftl`, even though the original intention seems to be that it should gracefully
+    // failover to the fallback bundle.
+
+    rustc()
+        .env("RUSTC_ICE", "0") // disable ICE dump file, not needed
+        .input("test.rs")
+        .arg("-Ztranslate-additional-ftl=broken.ftl")
+        .run_fail()
+        .assert_exit_code(101);
+}
+
+#[track_caller]
+fn shallow_symlink_dir_entries(src_dir: &Path, dst_dir: &Path) {
+    for entry in rfs::read_dir(src_dir) {
+        let entry = entry.unwrap();
+        let src_entry_path = entry.path();
+        let src_filename = src_entry_path.file_name().unwrap();
+        let meta = rfs::symlink_metadata(&src_entry_path);
+
+        if meta.is_symlink() || meta.is_file() {
+            rfs::symlink_file(&src_entry_path, dst_dir.join(src_filename));
+        } else if meta.is_dir() {
+            rfs::symlink_dir(&src_entry_path, dst_dir.join(src_filename));
+        } else {
+            unreachable!()
+        }
+    }
+}
+
+#[track_caller]
+fn shallow_symlink_dir_entries_materialize_single_dir(
+    src_dir: &Path,
+    dst_dir: &Path,
+    dir_filename: &str,
+) {
+    shallow_symlink_dir_entries(src_dir, dst_dir);
+    rfs::remove_file(dst_dir.join(dir_filename));
+    rfs::create_dir_all(dst_dir.join(dir_filename));
+}
+
+#[track_caller]
+fn setup_fakeroot_parents() -> PathBuf {
+    let sysroot = sysroot();
+    let fakeroot = cwd().join("fakeroot");
+    rfs::create_dir_all(&fakeroot);
+    shallow_symlink_dir_entries_materialize_single_dir(&sysroot, &fakeroot, "lib");
+    shallow_symlink_dir_entries_materialize_single_dir(
+        &sysroot.join("lib"),
+        &fakeroot.join("lib"),
+        "rustlib",
+    );
+    shallow_symlink_dir_entries_materialize_single_dir(
+        &sysroot.join("lib").join("rustlib"),
+        &fakeroot.join("lib").join("rustlib"),
+        "src",
+    );
+    shallow_symlink_dir_entries(
+        &sysroot.join("lib").join("rustlib").join("src"),
+        &fakeroot.join("lib").join("rustlib").join("src"),
+    );
+    fakeroot
+}
+
+/// Check that a locale can be loaded from the sysroot given a language identifier by making a local
+/// copy of the sysroot and adding the custom locale to it.
+fn locale_sysroot() {
+    run_in_tmpdir(|| {
+        let fakeroot = setup_fakeroot_parents();
+
+        // When download-rustc is enabled, real sysroot will have a share directory. Delete the link
+        // to it.
+        let _ = std::fs::remove_file(fakeroot.join("share"));
+
+        let fake_locale_path = fakeroot.join("share").join("locale").join("zh-CN");
+        rfs::create_dir_all(&fake_locale_path);
+        rfs::symlink_file(
+            cwd().join("working.ftl"),
+            fake_locale_path.join("basic-translation.ftl"),
+        );
+
+        rustc()
+            .env("RUSTC_ICE", "0")
+            .input("test.rs")
+            .sysroot(&fakeroot)
+            .arg("-Ztranslate-lang=zh-CN")
+            .run_fail()
+            .assert_stderr_contains("this is a test message");
+    });
+}
+
+/// Check that the compiler errors out when the sysroot requested cannot be found. This test might
+/// start failing if there actually exists a Klingon translation of rustc's error messages.
+fn missing_sysroot() {
+    run_in_tmpdir(|| {
+        rustc()
+            .input("test.rs")
+            .arg("-Ztranslate-lang=tlh")
+            .run_fail()
+            .assert_stderr_contains("missing locale directory");
+    });
+}
+
+/// Check that the compiler errors out when the directory for the locale in the sysroot is actually
+/// a file.
+fn file_sysroot() {
+    run_in_tmpdir(|| {
+        let fakeroot = setup_fakeroot_parents();
+        rfs::create_dir_all(fakeroot.join("share").join("locale"));
+        rfs::write(fakeroot.join("share").join("locale").join("zh-CN"), b"not a dir");
+
+        rustc()
+            .input("test.rs")
+            .sysroot(&fakeroot)
+            .arg("-Ztranslate-lang=zh-CN")
+            .run_fail()
+            .assert_stderr_contains("is not a directory");
+    });
+}