Bad error message aliasing an ident with a path. #1481.

releasenotes.md

@@ -61,6 +61,7 @@
 - Fix bug due to enum associated values not being checked for liveness.
 - Regression when compile time accessing a union field not last assigned to.
 - Safer seed of rand() for WASM without libc.
+- Bad error message aliasing an ident with a path. #1481.
 
 ### Stdlib changes
 - Additional init functions for hashmap.

src/compiler/parse_global.c

@@ -1901,8 +1901,28 @@ static inline Decl *parse_def_type(ParseContext *c)
 	}
 
 	// 2. Now parse the type which we know is here.
-	ASSIGN_TYPE_OR_RET(TypeInfo *type_info, parse_type(c), poisoned_decl);
 
+	ASSIGN_EXPR_OR_RET(Expr *expr, parse_expr(c), poisoned_decl);
+	TypeInfo *type_info;
+	switch (expr->expr_kind)
+	{
+		case EXPR_TYPEINFO:
+			type_info = expr->type_expr;
+			break;
+		case EXPR_IDENTIFIER:
+			if (expr->identifier_expr.is_const)
+			{
+				print_error_at(decl->span, "A constant may not have a type name alias, it must have an all caps name.");
+			}
+			else
+			{
+				print_error_at(decl->span, "An identifier may not be aliased with type name, it must start with a lower case letter.");
+			}
+			return poisoned_decl;
+		default:
+			PRINT_ERROR_HERE("Expected a type to alias here.");
+			return poisoned_decl;
+	}
 	assert(!tok_is(c, TOKEN_LGENPAR));
 
 	decl->typedef_decl.type_info = type_info;

test/test_suite/define/alias_typename.c3

@@ -0,0 +1,2 @@
+def ShouldNotBeUppercase = FOO; // #error: A constant may not have a type name
+def ShouldNotBeUppercase2 = abc; // #error: An identifier may not be aliased

test/test_suite/define/common.c3

@@ -9,7 +9,7 @@ def A_CONST_INT = A_CONST(<int>);
 def standard_foo(<int>) = ofke; // #error: Expected '='
 def fn foo = fef; // #error: A type, variable, constant or attribute name was expected here
 def feokfe = fn void(int); // #error: This looks like you're declaring a function type alias
-def Helo = helo; // #error: A type name was expected, but this looks a variable
-def Helo = OFKE; // #error: A type name was expected here
+def Helo = helo; // #error: An identifier may not be aliased
+def Helo = OFKE; // #error: A constant may not have a type name alias
 def int = int; // #error: 'int' is a reserved keyword, try another name
 def main = foo; // #error: 'main' is reserved and cannot be used as an alias.