Handle closures that are invalid for Aleo.

compiler/passes/src/code_generation/visit_program.rs

@@ -222,6 +222,14 @@ impl<'a> CodeGenerator<'a> {
 
         //  Construct and append the function body.
         let block_string = self.visit_block(&function.block);
+        if matches!(self.variant.unwrap(), Variant::Function | Variant::AsyncFunction)
+            && block_string.lines().all(|line| line.starts_with("    output "))
+        {
+            // There are no real instructions, which is invalid in Aleo, so
+            // add a dummy instruction.
+            function_string.push_str("    assert.eq true true;\n");
+        }
+
         function_string.push_str(&block_string);
 
         function_string

compiler/passes/src/type_checking/check_program.rs

@@ -263,11 +263,6 @@ impl<'a, N: Network> ProgramVisitor<'a> for TypeChecker<'a, N> {
         self.check_function_signature(function);
 
         if self.scope_state.variant == Some(Variant::AsyncFunction) {
-            // Async functions cannot have empty blocks
-            if function.block.statements.is_empty() {
-                self.emit_err(TypeCheckerError::finalize_block_must_not_be_empty(function.block.span));
-            }
-
             // Initialize the list of input futures. Each one must be awaited before the end of the function.
             self.await_checker.set_futures(
                 function
@@ -280,6 +275,10 @@ impl<'a, N: Network> ProgramVisitor<'a> for TypeChecker<'a, N> {
             );
         }
 
+        if function.variant == Variant::Function && function.input.is_empty() {
+            self.emit_err(TypeCheckerError::empty_function_arglist(function.span));
+        }
+
         self.visit_block(&function.block);
 
         // If the function has a return type, then check that it has a return.

errors/src/errors/parser/parser_errors.rs

@@ -73,7 +73,7 @@ create_messages!(
     }
 
     /// For when the parser encountered a mix of commas and semi-colons in struct member variables.
-    // TODO unused
+    // TODO This error is unused. Remove it in a future version.
     @formatted
     mixed_commas_and_semicolons {
         args: (),

errors/src/errors/type_checker/type_checker_error.rs

@@ -340,6 +340,7 @@ create_messages!(
         help: None,
     }
 
+    // TODO This error is unused. Remove it in a future version.
     @formatted
     finalize_block_must_not_be_empty {
         args: (),
@@ -886,4 +887,11 @@ create_messages!(
         msg: "A struct must have at least one member.".to_string(),
         help: None,
     }
+
+    @formatted
+    empty_function_arglist {
+        args: (),
+        msg: format!("Cannot define a function with no parameters."),
+        help: None,
+    }
 );

tests/expectations/compiler/finalize/empty_finalize.out

@@ -0,0 +1,16 @@
+namespace = "Compile"
+expectation = "Pass"
+outputs = [[{ compile = [{ initial_symbol_table = "1594125e96833cb52afcad4c876e44d61b2944a6c146e019b23fa0ad5d39db2a", type_checked_symbol_table = "95d8ce7541440d2568f633e1b7800d3d5d06e1147642eec802bfca4a9115e61c", unrolled_symbol_table = "95d8ce7541440d2568f633e1b7800d3d5d06e1147642eec802bfca4a9115e61c", initial_ast = "45d32cf0414a246717747dc917b07ffe55ff7587589d4c494479e18667e61a03", unrolled_ast = "45d32cf0414a246717747dc917b07ffe55ff7587589d4c494479e18667e61a03", ssa_ast = "eb6eff57864e407c245edbba3ab2949a2536643b3b864a8a42b65c348523a31f", flattened_ast = "6e8cc40e042029b3124b7b9a7e66905525207fb6cf0bfe5b71abfecbf10d7c72", destructured_ast = "22c2d4f79894ead71296929de2982b8289e2b43f7d83dc497a1be4532945ea17", inlined_ast = "e18c2f95e617c4c42c2359ea8a09924311f89c0c3a0bfa1e2ffe23c6ff933846", dce_ast = "e18c2f95e617c4c42c2359ea8a09924311f89c0c3a0bfa1e2ffe23c6ff933846", bytecode = """
+program test.aleo;
+
+function mint_public:
+    input r0 as address.public;
+    input r1 as u64.public;
+    async mint_public r0 r1 into r2;
+    output r2 as test.aleo/mint_public.future;
+
+finalize mint_public:
+    input r0 as address.public;
+    input r1 as u64.public;
+    assert.eq true true;
+""", errors = "", warnings = "" }] }]]

tests/expectations/compiler/function/empty_arglist_fail.out

@@ -0,0 +1,18 @@
+namespace = "Compile"
+expectation = "Fail"
+outputs = ["""
+Error [ETYC0372113]: Cannot define a function with no parameters.
+    --> compiler-test:4:5
+     |
+   4 |     function x() -> u8 {
+   5 |         return 0u8;
+   6 |     }
+     |     ^
+Error [ETYC0372083]: A program must have at least one transition function.
+    --> compiler-test:1:1
+     |
+   1 | 
+   2 | 
+   3 | program test.aleo {
+     | ^^^^^^^^^^^^
+"""]

tests/expectations/compiler/function/empty_function.out

@@ -0,0 +1,15 @@
+namespace = "Compile"
+expectation = "Pass"
+outputs = [[{ compile = [{ initial_symbol_table = "4ccc1709fb6b2aad9ee9a247bb37098d9330087d64e14af2a5c064287f701105", type_checked_symbol_table = "979420a8fc4bfbc81aeabe709704af919277f62699a09b0858c37544622a725a", unrolled_symbol_table = "979420a8fc4bfbc81aeabe709704af919277f62699a09b0858c37544622a725a", initial_ast = "52950f91033f987381d1b9a5ff69b626a8911d003da7edb503e97bd6e6637d2c", unrolled_ast = "52950f91033f987381d1b9a5ff69b626a8911d003da7edb503e97bd6e6637d2c", ssa_ast = "5314cb0ebd490a53c7ded487668632260992a4f49a10f1e247980b5c6647ad22", flattened_ast = "85fd8c8ed0cae4cd4b711d8d909d5aec0a176028fa91452fae92fbe5f6091f63", destructured_ast = "fc6b028060914573cc2c1885155f4f2bb5c90ed03caf720bff4d5b05eb299327", inlined_ast = "6b8711898970669f70badb94f5ce2abd87be07fbb764523dd2d9e6d94336e7cd", dce_ast = "6b8711898970669f70badb94f5ce2abd87be07fbb764523dd2d9e6d94336e7cd", bytecode = """
+program test.aleo;
+
+closure x:
+    input r0 as boolean;
+    assert.eq true true;
+    output 0u8 as u8;
+
+function t:
+    input r0 as boolean.private;
+    call x r0 into r1;
+    output r1 as u8.private;
+""", errors = "", warnings = "" }] }]]

tests/expectations/compiler/tuple/tuple_not_allowed_fail.out

@@ -12,10 +12,10 @@ Error [ETYC0372051]: A function cannot take in a tuple as input.
    8 |     function foo(a: (u8, u16)) -> (u8, u16) {
      |                  ^
 Error [ETYC0372049]: A tuple type cannot contain a tuple.
-    --> compiler-test:12:28
+    --> compiler-test:12:36
      |
-  12 |     function bar() -> (u8, (u16, u32)) {
-     |                            ^^^^^^^^^^
+  12 |     function bar(zz: bool) -> (u8, (u16, u32)) {
+     |                                    ^^^^^^^^^^
 Error [ETYC0372052]: A tuple expression cannot contain another tuple expression.
     --> compiler-test:13:22
      |

tests/tests/compiler/core/algorithms/pedersen_fail.leo

@@ -4,7 +4,7 @@ expectation = "Fail"
 */
 
 program test.aleo {    
-    function main() -> bool {
+    function main(zz: bool) -> bool {
         let a: group = Pedersen64::hash_to_field(1u128); // Pedersen64 hash_to_field returns a field type
 
         return true;

tests/tests/compiler/field/no_space_between_literal.leo

@@ -4,6 +4,6 @@ expectation = "Fail"
 */
 
 program test.aleo {    
-    function main() {
+    function main(x: bool) {
       let f = 1 field;
     }}

tests/tests/compiler/finalize/empty_finalize_fail.leo → tests/tests/compiler/finalize/empty_finalize.leo

@@ -1,6 +1,6 @@
 /*
 namespace = "Compile"
-expectation = "Fail"
+expectation = "Pass"
 */
 
 program test.aleo {    

tests/tests/compiler/function/empty_arglist_fail.leo

@@ -0,0 +1,10 @@
+/*
+namespace = "Compile"
+expectation = "Fail"
+*/
+
+program test.aleo {
+    function x() -> u8 {
+        return 0u8;
+    }
+}

tests/tests/compiler/function/empty_function.leo

@@ -0,0 +1,16 @@
+/*
+namespace = "Compile"
+expectation = "Pass"
+*/
+
+program test.aleo {
+    // This should pass and insert
+    // a dummy instruction into the empty function.
+    function x(a: bool) -> u8 {
+        return 0u8;
+    }
+
+    transition t(a: bool) -> u8 {
+        return x(a);
+    }
+}

tests/tests/compiler/function/undefined_fail.leo

@@ -4,7 +4,7 @@ expectation = "Fail"
 */
 
 program test.aleo {    
-    function main() -> u8 {
+    function main(zz: bool) -> u8 {
         my_function();
         return 0u8;
     }

tests/tests/compiler/group/no_space_between_literal.leo

@@ -4,7 +4,7 @@ expectation = "Fail"
 */
 
 program test.aleo {    
-    function main() -> group {
+    function main(x: bool) -> group {
       let g: group = (0,1) group;
       return g;
     }}

tests/tests/compiler/integers/i128/max_fail.leo

@@ -4,7 +4,7 @@ expectation = "Fail"
 */
 
 program test.aleo {    
-    function main() {
+    function main(x: bool) {
         let a: i128 = 170141183460469231731687303715884105728i128;
     }
 }

tests/tests/compiler/integers/i128/no_space_between_literal.leo

@@ -4,7 +4,7 @@ expectation = "Fail"
 */
 
 program test.aleo {    
-    function main() {
+    function main(x: bool) {
         let i = 1 i128;
     }
 }

tests/tests/compiler/integers/i16/no_space_between_literal.leo

@@ -4,7 +4,7 @@ expectation = "Fail"
 */
 
 program test.aleo {    
-    function main() {
+    function main(x: bool) {
         let i = 1 i16;
     }
 }

tests/tests/compiler/integers/i32/max_fail.leo

@@ -4,7 +4,7 @@ expectation = "Fail"
 */
 
 program test.aleo {    
-    function main() {
+    function main(x: bool) {
         let a: i32 = 2147483648i32;
     }
 }

tests/tests/compiler/integers/i32/no_space_between_literal.leo

@@ -4,7 +4,7 @@ expectation = "Fail"
 */
 
 program test.aleo {    
-    function main() {
+    function main(x: bool) {
         let i = 1 i32;
     }
 }

tests/tests/compiler/integers/i64/max_fail.leo

@@ -4,7 +4,7 @@ expectation = "Fail"
 */
 
 program test.aleo {    
-    function main() {
+    function main(x: bool) {
         let a: i64 = 9223372036854775808i64;
     }
 }

tests/tests/compiler/integers/i64/no_space_between_literal.leo

@@ -4,7 +4,7 @@ expectation = "Fail"
 */
 
 program test.aleo {    
-    function main() {
+    function main(x: bool) {
         let i = 1 i64;
     }
 }

tests/tests/compiler/integers/i8/max_fail.leo

@@ -4,6 +4,6 @@ expectation = "Fail"
 */
 
 program test.aleo {    
-    function main() {
+    function main(x: bool) {
         let a: i8 = 128i8;
     }}

tests/tests/compiler/integers/i8/no_space_between_literal.leo

@@ -4,7 +4,7 @@ expectation = "Fail"
 */
 
 program test.aleo {    
-    function main() {
+    function main(x: bool) {
         let i = 1 i8;
     }
 }

tests/tests/compiler/integers/u128/hex_min_fail.leo

@@ -4,7 +4,7 @@ expectation = "Fail"
 */
 
 program test.aleo {    
-    function main() {
+    function main(x: bool) {
         let a: u128 = -0x1u128;
     }
 }

tests/tests/compiler/integers/u128/max_fail.leo

@@ -4,7 +4,7 @@ expectation = "Fail"
 */
 
 program test.aleo {    
-    function main() {
+    function main(x: bool) {
         let a: u128 = 340282366920938463463374607431768211456u128;
     }
 }

tests/tests/compiler/integers/u128/min_fail.leo

@@ -4,7 +4,7 @@ expectation = "Fail"
 */
 
 program test.aleo {    
-    function main() {
+    function main(x: bool) {
         let a: u128 = -1u128;
     }
 }

tests/tests/compiler/integers/u128/no_space_between_literal.leo

@@ -4,7 +4,7 @@ expectation = "Fail"
 */
 
 program test.aleo {    
-    function main() {
+    function main(x: bool) {
         let i = 1 u128;
     }
 }

tests/tests/compiler/integers/u16/hex_min_fail.leo

@@ -4,7 +4,7 @@ expectation = "Fail"
 */
 
 program test.aleo {    
-    function main() {
+    function main(x: bool) {
         let a: u16 = -0x1u16;
     }
 }

tests/tests/compiler/integers/u16/max_fail.leo

@@ -4,7 +4,7 @@ expectation = "Fail"
 */
 
 program test.aleo {    
-    function main() {
+    function main(x: bool) {
         let a: u16 = 65536u16;
     }
 }

tests/tests/compiler/integers/u16/min_fail.leo

@@ -4,7 +4,7 @@ expectation = "Fail"
 */
 
 program test.aleo {    
-    function main() {
+    function main(x: bool) {
         let a: u16 = -1u16;
     }
 }

tests/tests/compiler/integers/u16/no_space_between_literal.leo

@@ -4,7 +4,7 @@ expectation = "Fail"
 */
 
 program test.aleo {    
-    function main() {
+    function main(x: bool) {
         let i = 1 u16;
     }
 }

tests/tests/compiler/integers/u32/hex_min_fail.leo

@@ -4,7 +4,7 @@ expectation = "Fail"
 */
 
 program test.aleo {    
-    function main() {
+    function main(x: bool) {
         let a: u32 = -0x1u32;
     }
 }