- Make foo.$abc implicitly mean foo.eval("$abc").

releasenotes.md

@@ -20,6 +20,7 @@
 - Module-based generics using {} is deprecated.
 - Create optional with `~` instead of `?`. `return io::EOF?;` becomes `return io::EOF~`.
 - Deprecated use of `?` to create optional.
+- Make `foo.$abc` implicitly mean `foo.eval("$abc")`.
 
 ### Fixes
 - Regression with npot vector in struct triggering an assert #2219.

src/compiler/enums.h

@@ -1756,6 +1756,13 @@ typedef enum
 	PARAM_RW_EXPAND_ELEMENTS,
 } ParamRewrite;
 
+typedef enum
+{
+	CT_EVAL_TYPE,
+	CT_EVAL_IDENTIFIER,
+	CT_EVAL_IMPLICIT_IDENTIFIER
+} CtEvalKind;
+
 // -- Arch helper macros
 #define ARCH_UNSUPPORTED ARCH_TYPE_AARCH64_32: case ARCH_TYPE_BPFEL: case ARCH_TYPE_BPFEB: case ARCH_TYPE_SPARCEL: \
  case ARCH_TYPE_LE64: case ARCH_TYPE_AMDIL: case ARCH_TYPE_AMDIL64: case ARCH_TYPE_HSAIL: case ARCH_TYPE_HSAIL64:  \

src/compiler/sema_expr.c

@@ -400,13 +400,22 @@ NO_PATH:
 	return NULL;
 }
 
-Expr *sema_ct_eval_expr(SemaContext *context, bool is_type_eval, Expr *inner, bool report_missing)
+Expr *sema_ct_eval_expr(SemaContext *context, CtEvalKind eval_kind, Expr *inner, bool report_missing)
 {
 	if (!sema_analyse_ct_expr(context, inner)) return NULL;
 	if (!expr_is_const_string(inner))
 	{
-		SEMA_ERROR(inner, "'%s' expects a constant string as the argument.", is_type_eval ? "$evaltype" : "$eval");
-		return poisoned_expr;
+		switch (eval_kind)
+		{
+			case CT_EVAL_TYPE:
+				RETURN_VAL_SEMA_ERROR(poisoned_expr, inner, "'$evaltype' expects a constant string as the argument.");
+			case CT_EVAL_IDENTIFIER:
+				RETURN_VAL_SEMA_ERROR(poisoned_expr, inner, "'$eval' expects a constant string as the argument.");
+			case CT_EVAL_IMPLICIT_IDENTIFIER:
+				RETURN_VAL_SEMA_ERROR(poisoned_expr, inner, "A constant string was expected as the argument.");
+			default:
+				UNREACHABLE
+		}
 	}
 	return sema_resolve_string_ident(context, inner, report_missing);
 }
@@ -4847,7 +4856,7 @@ static inline bool sema_expr_analyse_slice(SemaContext *context, Expr *expr)
  * 3. .@foo -> It is a macro.
  * 4. .#bar -> It is an identifier to resolve as a member or a function
  * 5. .$eval(...) -> resolve the eval and retry.
- * 6. .$ident -> It is a child to resolve as CT param
+ * 6. .$ident -> resolve as `$eval($ident)`
  * 7. .$Type -> It is a child to resolve as CT type param
  */
  Expr *sema_expr_resolve_access_child(SemaContext *context, Expr *child, bool *missing)
@@ -4876,8 +4885,17 @@ RETRY:
 			if (child->unresolved_ident_expr.path) break;
 			return child;
 		case EXPR_CT_IDENT:
-			if (child->resolve_status == RESOLVE_DONE) goto ALREADY_RESOLVED;
-			return child;
+		{
+			Expr *result = sema_ct_eval_expr(context, CT_EVAL_IMPLICIT_IDENTIFIER, child, missing == NULL);
+			if (!expr_ok(result)) return NULL;
+			if (!result)
+			{
+				if (missing) *missing = true;
+				return NULL;
+			}
+			expr_replace(child, result);
+			goto RETRY;
+		}
 		case EXPR_TYPEINFO:
 			if (child->type_expr->kind == TYPE_INFO_CT_IDENTIFIER) return child;
 			break;
@@ -4885,7 +4903,7 @@ RETRY:
 		{
 			ASSERT_SPAN(child, child->resolve_status != RESOLVE_DONE);
 			// Only report missing if missing var is NULL
-			Expr *result = sema_ct_eval_expr(context, false, child->inner_expr, missing == NULL);
+			Expr *result = sema_ct_eval_expr(context, CT_EVAL_IDENTIFIER, child->inner_expr, missing == NULL);
 			if (!expr_ok(result)) return NULL;
 			if (!result)
 			{
@@ -10529,7 +10547,7 @@ RETRY:
 		case TYPE_INFO_EVALTYPE:
 		{
 			Expr *expr = type_info->unresolved_type_expr;
-			expr = sema_ct_eval_expr(context, true, expr, false);
+			expr = sema_ct_eval_expr(context, CT_EVAL_TYPE, expr, false);
 			if (!expr_ok(expr)) return poisoned_type;
 			if (!expr) return NULL;
 			if (expr->expr_kind != EXPR_TYPEINFO)
@@ -11088,7 +11106,7 @@ static inline bool sema_expr_analyse_ct_defined(SemaContext *context, Expr *expr
 			}
 			case EXPR_CT_EVAL:
 			{
-				Expr *eval = sema_ct_eval_expr(active_context, "$eval", main_expr->inner_expr, false);
+				Expr *eval = sema_ct_eval_expr(active_context, CT_EVAL_IDENTIFIER, main_expr->inner_expr, false);
 				if (!expr_ok(eval)) return false;
 				if (eval)
 				{
@@ -11499,7 +11517,7 @@ static inline bool sema_expr_analyse_ct_stringify(SemaContext *context, Expr *ex
 
 static inline bool sema_expr_resolve_ct_eval(SemaContext *context, Expr *expr)
 {
-	Expr *result = sema_ct_eval_expr(context, false, expr->inner_expr, true);
+	Expr *result = sema_ct_eval_expr(context, CT_EVAL_IDENTIFIER, expr->inner_expr, true);
 	if (!result) return false;
 	if (result->expr_kind == EXPR_TYPEINFO)
 	{

src/compiler/sema_internal.h

@@ -108,7 +108,8 @@ void sema_add_methods_to_decl_stack(SemaContext *context, Decl *decl);
 
 bool sema_expr_analyse_macro_call(SemaContext *context, Expr *call_expr, Expr *struct_var, Decl *decl, bool call_var_optional, bool *no_match_ref);
 Expr *sema_expr_analyse_ct_arg_index(SemaContext *context, Expr *index_expr, unsigned *index_ref);
-Expr *sema_ct_eval_expr(SemaContext *context, bool is_type_eval, Expr *inner, bool report_missing);
+
+Expr *sema_ct_eval_expr(SemaContext *context, CtEvalKind eval_kind, Expr *inner, bool report_missing);
 Expr *sema_resolve_string_ident(SemaContext *context, Expr *inner, bool report_missing);
 bool sema_analyse_asm(SemaContext *context, AsmInlineBlock *block, Ast *asm_stmt);
 bool sema_expr_analyse_sprintf(SemaContext *context, Expr *expr, Expr *format_string, Expr **args, unsigned num_args);

src/compiler/sema_types.c

@@ -300,7 +300,7 @@ INLINE bool sema_resolve_evaltype(SemaContext *context, TypeInfo *type_info, Res
 {
 	SEMA_DEPRECATED(type_info, "$evaltype is deprecated, use $typefrom instead.");
 	Expr *expr = type_info->unresolved_type_expr;
-	Expr *inner = sema_ct_eval_expr(context, true, expr, true);
+	Expr *inner = sema_ct_eval_expr(context, CT_EVAL_TYPE, expr, true);
 	if (!inner || !expr_ok(inner)) return type_info_poison(type_info);
 	if (inner->expr_kind != EXPR_TYPEINFO)
 	{

test/test_suite/compile_time/implicit_eval_access.c3t

@@ -0,0 +1,23 @@
+// #target: macos-x64
+module test;
+struct Bar
+{
+	struct { union { struct { char z1; } } }
+}
+
+fn void main()
+{
+	var $x = "alignof";
+	int a = Bar.z1.offsetof;
+	int b = Bar.z1.$x;
+}
+
+/* #expect: test.ll
+
+entry:
+  %a = alloca i32, align 4
+  %b = alloca i32, align 4
+  store i32 0, ptr %a, align 4
+  store i32 1, ptr %b, align 4
+  ret void
+}