Improve error message when using functions as values #2856

releasenotes.md

@@ -4,6 +4,7 @@
 
 ### Changes / improvements
 - Method resolution and `$define` now works together well unless definitions are out of order for real.
+- Improve error message when using functions as values #2856
 
 ### Stdlib changes
 - Summarize sort macros as generic function wrappers to reduce the amount of generated code. #2831

src/compiler/compiler.c

@@ -65,7 +65,8 @@ void compiler_init(BuildOptions *build_options)
 
 	INFO_LOG("Version: %s", COMPILER_VERSION);
 
-	compiler.context = (GlobalContext) { .in_panic_mode = false };
+	GlobalContext new_context = { .in_panic_mode = false };
+	compiler.context = new_context;
 	// Skip library detection.
 	//compiler.lib_dir = find_lib_dir();
 	//DEBUG_LOG("Found std library: %s", compiler.lib_dir);

src/compiler/expr.c

@@ -592,7 +592,7 @@ void expr_insert_addr(Expr *original)
 	Expr *inner = expr_copy(original);
 	original->expr_kind = EXPR_UNARY;
 	original->type = new_type;
-	original->unary_expr = (ExprUnary) { .operator = UNARYOP_ADDR, .expr = inner };
+	original->unary_expr = (ExprUnary) { .operator = UNARYOP_ADDR, .expr = inner, .no_wrap = false, .no_read = false };
 }
 
 Expr *expr_generated_local(Expr *assign, Decl **decl_ref)
@@ -1189,6 +1189,6 @@ void expr_rewrite_const_string(Expr *expr_to_rewrite, const char *string)
 
 void expr_rewrite_to_binary(Expr *expr_to_rewrite, Expr *left, Expr *right, BinaryOp op)
 {
-	expr_to_rewrite->binary_expr = (ExprBinary) { .operator = op, .left = exprid(left), .right = exprid(right) };
+	expr_to_rewrite->binary_expr = (ExprBinary) { .operator = op, .left = exprid(left), .right = exprid(right), .grouped = false };
 	expr_to_rewrite->expr_kind = EXPR_BINARY;
 }

src/compiler/sema_decls.c

@@ -3691,7 +3691,8 @@ static inline bool sema_analyse_custom_attribute(SemaContext *context, ResolvedA
 	SemaContext eval_context;
 	sema_context_init(&eval_context, attr_decl->unit);
 	eval_context.macro_call_depth = context->macro_call_depth + 1;
-	eval_context.call_env = (CallEnv) { .kind = CALL_ENV_ATTR, .attr_declaration = decl,  };
+	CallEnv eval_env = { .kind = CALL_ENV_ATTR, .attr_declaration = decl,  };
+	eval_context.call_env = eval_env;
 	// We copy the compilation unit.
 	eval_context.compilation_unit = context->unit;
 
@@ -5372,7 +5373,8 @@ FOUND:;
 		{
 			SemaContext context_gen;
 			sema_context_init(&context_gen, decl->unit);
-			context_gen.active_scope = (DynamicScope) { .depth = 0 };
+			DynamicScope empty = { .depth = 0 };
+			context_gen.active_scope = empty;
 			sema_analyse_decl(&context_gen, decl);
 			context_gen.generic_instance = instance;
 			sema_analyse_inner_func_ptr(&context_gen, decl);

src/compiler/sema_expr.c

@@ -953,9 +953,8 @@ static inline bool sema_cast_ident_rvalue(SemaContext *context, Expr *expr)
 	decl = decl_flatten(decl);
 	switch (decl->decl_kind)
 	{
-		case DECL_FNTYPE:
 		case DECL_FUNC:
-			SEMA_ERROR(expr, "Expected function followed by (...) or prefixed by &.");
+			SEMA_ERROR(expr, "A function name cannot be used as a value, did you want to pass it by pointer? If so then you need to add '&', like '&%s'.", decl->span);
 			return expr_poison(expr);
 		case DECL_MACRO:
 			SEMA_ERROR(expr, "Expected a macro followed by (...).");
@@ -968,6 +967,7 @@ static inline bool sema_cast_ident_rvalue(SemaContext *context, Expr *expr)
 		case DECL_FAULT:
 			expr_rewrite_const_fault(expr, decl);
 			return true;
+		case DECL_FNTYPE:
 		case DECL_ALIAS:
 		case DECL_ALIAS_PATH:
 		case DECL_ATTRIBUTE:
@@ -1647,7 +1647,8 @@ static bool sema_analyse_parameter(SemaContext *context, Expr *arg, Decl *param,
 			{
 				Expr *inner = expr_copy(arg);
 				arg->expr_kind = EXPR_OTHER_CONTEXT;
-				arg->expr_other_context = (ExprOtherContext) { .context = context, .inner = inner };
+				ExprOtherContext other = { .context = context, .inner = inner };
+				arg->expr_other_context = other;
 				arg->resolve_status = RESOLVE_NOT_DONE;
 			}
 			break;
@@ -3599,8 +3600,9 @@ FOUND:;
 	new_path->module = kw_std__core__runtime;
 	new_path->span = expr->span;
 	new_path->len = strlen(kw_std__core__runtime);
-	call->unresolved_ident_expr = (ExprUnresolvedIdentifier) { .ident = kw_at_enum_lookup, .path = new_path };
-	expr->call_expr = (ExprCall) { .arguments = args, .function = exprid(call) };
+	call->unresolved_ident_expr = (ExprUnresolvedIdentifier) { .ident = kw_at_enum_lookup, .path = new_path, .is_const = false };
+	ExprCall call_expr = { .arguments = args, .function = exprid(call) };
+	expr->call_expr = call_expr;
 	expr->resolve_status = RESOLVE_NOT_DONE;
 	return sema_analyse_expr_rvalue(context, expr);
 }
@@ -7405,8 +7407,8 @@ AFTER_ADDR:;
 	// init, expr -> lvalue = rvalue + a
 	expr->expr_kind = EXPR_BINARY;
 	left->expr_kind = EXPR_BINARY;
-	left->binary_expr = (ExprBinary) { .left = exprid(left_lvalue), .right = exprid(right), new_op };
-	expr->binary_expr = (ExprBinary) { .left = exprid(left_rvalue), .right = exprid(left), .operator = BINARYOP_ASSIGN, .grouped = false };
+	left->binary_expr = (ExprBinary) { exprid(left_lvalue), exprid(right), new_op, false };
+	expr->binary_expr = (ExprBinary) { exprid(left_rvalue), exprid(left), BINARYOP_ASSIGN, false };
 	expr->resolve_status = RESOLVE_NOT_DONE;
 	left->resolve_status = RESOLVE_NOT_DONE;
 	Expr *binary = expr_copy(expr);

src/compiler/sema_stmts.c

@@ -915,7 +915,7 @@ static inline bool sema_analyse_try_unwrap(SemaContext *context, Expr *expr)
 			RETURN_SEMA_ERROR(ident, "Expected this variable to be an optional, otherwise it can't be used for unwrap, maybe you didn't intend to use 'try'?");
 		}
 		expr->expr_kind = EXPR_TRY;
-		expr->try_expr = (ExprTry) { .decl = decl };
+		expr->try_expr = (ExprTry) { .decl = decl, .assign_existing = false };
 		expr->type = type_bool;
 		sema_unwrap_var(context, decl);
 		expr->resolve_status = RESOLVE_DONE;
@@ -977,7 +977,7 @@ static inline bool sema_analyse_try_unwrap(SemaContext *context, Expr *expr)
 	if (!sema_analyse_var_decl(context, decl, true, NULL)) return false;
 
 	expr->expr_kind = EXPR_TRY;
-	expr->try_expr = (ExprTry) { .decl = decl, .optional = optional };
+	expr->try_expr = (ExprTry) { .decl = decl, .optional = optional, .assign_existing = false };
 	expr->type = type_bool;
 	expr->resolve_status = RESOLVE_DONE;
 	return true;
@@ -3449,21 +3449,24 @@ bool sema_analyse_function_body(SemaContext *context, Decl *func)
 
 	// Set up the context for analysis
 	context->original_module = NULL;
-	context->call_env = (CallEnv) {
+	CallEnv env = {
 		.current_function = func,
 		.is_naked_fn = func->func_decl.attr_naked,
 		.kind = CALL_ENV_FUNCTION,
 		.pure = func->func_decl.signature.attrs.is_pure,
 		.ignore_deprecation = func->allow_deprecated || decl_is_deprecated(func)
 	};
+	context->call_env = env;
 
 	Type *rtype = context->rtype = typeget(signature->rtype);
 	context->macro_call_depth = 0;
-	context->active_scope = (DynamicScope) {
-			.depth = 0,
-			.label_start = 0,
-			.current_local = 0
+	DynamicScope new_scope = {
+		.depth = 0,
+		.label_start = 0,
+		.current_local = 0
 	};
+
+	context->active_scope = new_scope;
 	vec_resize(context->ct_locals, 0);
 	// Clear returns
 	vec_resize(context->block_returns, 0);

src/compiler/semantic_analyser.c

@@ -35,18 +35,19 @@ void context_change_scope_with_flags(SemaContext *context, ScopeFlags flags, Sou
 	if (is_macro) flags &= ~(SCOPE_ENSURE | SCOPE_ENSURE_MACRO);
 
 	unsigned label_start = new_label_scope ? last_local : context->active_scope.label_start;
-	context->active_scope = (DynamicScope) {
-			.allow_dead_code = false,
-			.is_dead = scope_is_dead,
-			.is_poisoned = scope_is_poisoned,
-			.depth = depth,
-			.current_local = last_local,
-			.label_start = label_start,
-			.in_defer = previous_defer,
-			.defer_last = parent_defer,
-			.defer_start = parent_defer,
-			.flags = flags,
+	DynamicScope new_scope = {
+		.allow_dead_code = false,
+		.is_dead = scope_is_dead,
+		.is_poisoned = scope_is_poisoned,
+		.depth = depth,
+		.current_local = last_local,
+		.label_start = label_start,
+		.in_defer = previous_defer,
+		.defer_last = parent_defer,
+		.defer_start = parent_defer,
+		.flags = flags,
 	};
+	context->active_scope = new_scope;
 }
 
 const char *context_filename(SemaContext *context)
@@ -144,7 +145,7 @@ void context_pop_defers_and_replace_ast(SemaContext *context, Ast *ast)
 	ASSERT(ast->ast_kind != AST_COMPOUND_STMT);
 	Ast *replacement = ast_copy(ast);
 	ast->ast_kind = AST_COMPOUND_STMT;
-	ast->compound_stmt = (AstCompoundStmt) { .first_stmt = astid(replacement) };
+	ast->compound_stmt = (AstCompoundStmt) { .first_stmt = astid(replacement), .parent_defer = 0 };
 	replacement->next = defer_first;
 }