- Bitstructs, unions and flexible arrays now correctly emitted in headers.

- Require `@export` functions to have `@export` types.

releasenotes.md

@@ -8,6 +8,7 @@
 - Improved error notes when call expressions have errors.
 - Trailing body arguments may now be `&ref`, `#hash`, `$const` and `$Type` arguments.
 - "panic-msg" setting to suppress panic message output.
+- Require `@export` functions to have `@export` types.
 
 ### Fixes
 - Error with unsigned compare in `@ensure` when early returning 0 #1207.
@@ -18,6 +19,7 @@
 - No longer possible to dereference a function pointer.
 - Fix bug with @jump miscompile.
 - Bit negate does implicit integer promotion.
+- Bitstructs, unions and flexible arrays now correctly emitted in headers.
 
 ### Stdlib changes
 - Added `remove_first_item` `remove_last_item` and `remove_item` as aliases for the `match` functions.

src/build/build_options.c

@@ -49,7 +49,7 @@ const char *trust_level[3] = {
 
 #define EOUTPUT(string, ...) fprintf(stderr, string "\n", ##__VA_ARGS__)
 #define PRINTF(string, ...) fprintf(stdout, string "\n", ##__VA_ARGS__) // NOLINT
-#define FAIL_WITH_ERR(string, ...) do { fprintf(stderr, "Error: " string "\n\n", ##__VA_ARGS__); usage(); exit_compiler(EXIT_FAILURE); } while (0)
+#define FAIL_WITH_ERR(string, ...) do { fprintf(stderr, "Error: " string "\n\n", ##__VA_ARGS__); usage(); exit_compiler(EXIT_FAILURE); } while (0) /* NOLINT */
 
 static void usage(void)
 {

src/compiler/compiler_internal.h

@@ -2471,6 +2471,7 @@ Type *type_find_parent_type(Type *type);
 bool type_is_subtype(Type *type, Type *possible_subtype);
 bool type_is_abi_aggregate(Type *type);
 bool type_is_int128(Type *type);
+Decl * type_no_export(Type *type);
 
 Type *type_from_token(TokenType type);
 bool type_is_user_defined(Type *type);

src/compiler/headers.c

@@ -4,9 +4,9 @@
 
 #include "compiler_internal.h"
 
-#define PRINTF(x, ...) fprintf(file, x, ## __VA_ARGS__)
+#define PRINTF(x, ...) fprintf(file, x, ## __VA_ARGS__) /* NOLINT */
 #define INDENT() indent_line(file, indent)
-#define OUT(file, x, ...) fprintf(file, x, ## __VA_ARGS__)
+#define OUT(file, x, ...) fprintf(file, x, ## __VA_ARGS__) /* NOLINT */
 
 static void header_gen_struct_union(FILE *file, int indent, Decl *decl);
 static void header_gen_maybe_generate_type(FILE *file, HTable *table, Type *type);
@@ -125,11 +125,8 @@ static void header_print_type(FILE *file, Type *type)
 			return;
 		case TYPE_DISTINCT:
 		case TYPE_TYPEDEF:
-			UNREACHABLE
 		case TYPE_FLEXIBLE_ARRAY:
-			header_print_type(file, type->array.base);
-			PRINTF("[]");
-			return;
+			UNREACHABLE
 		case TYPE_ARRAY:
 			PRINTF("struct { ");
 			header_print_type(file, type->array.base);
@@ -203,6 +200,7 @@ static void header_gen_function_ptr(FILE *file, HTable *table, Type *type)
 static void header_gen_function(FILE *file, FILE *file_types, HTable *table, Decl *decl)
 {
 	if (!decl->is_export) return;
+	if (decl->name[0] == '_' && decl->name[1] == '_') return;
 	Signature *sig = &decl->func_decl.signature;
 	PRINTF("extern ");
 	Type *rtype = typeget(sig->rtype);
@@ -240,23 +238,41 @@ static void header_gen_members(FILE *file, int indent, Decl **members)
 	VECEACH(members, i)
 	{
 		Decl *member = members[i];
+		Type *type = type_flatten(member->type);
 		switch (member->decl_kind)
 		{
 			case DECL_VAR:
 				INDENT();
-				if (member->type->canonical->type_kind == TYPE_ARRAY)
+				switch (type->type_kind)
 				{
-					header_print_type(file, member->type->canonical->array.base);
-					PRINTF(" %s[%d];\n", member->name, member->type->canonical->array.len);
-					break;
+					case TYPE_ARRAY:
+						header_print_type(file, type->array.base);
+						PRINTF(" %s[%d];\n", member->name, type->array.len);
+						break;
+					case TYPE_FLEXIBLE_ARRAY:
+						header_print_type(file, type->array.base);
+						PRINTF(" %s[];\n", member->name);
+						break;
+					default:
+						header_print_type(file, member->type);
+						PRINTF(" %s;\n", member->name);
+						break;
 				}
-				header_print_type(file, member->type);
-				PRINTF(" %s;\n", member->name);
 				break;
 			case DECL_STRUCT:
 			case DECL_UNION:
 				header_gen_struct_union(file, indent, member);
 				break;
+			case DECL_BITSTRUCT:
+				INDENT();
+				header_print_type(file, member->bitstruct.base_type->type->canonical);
+				if (member->name)
+				{
+					PRINTF(" %s;\n", member->name);
+					break;
+				}
+				PRINTF(" __bits%d;\n", i);
+				break;
 			default:
 				UNREACHABLE
 		}
@@ -266,7 +282,7 @@ static void header_gen_struct_union(FILE *file, int indent, Decl *decl)
 {
 	if (!indent)
 	{
-		PRINTF("typedef struct %s__ %s;\n", decl->extname, decl->extname);
+		PRINTF("typedef %s %s__ %s;\n", struct_union_str(decl), decl->extname, decl->extname);
 	}
 	INDENT();
 	if (decl->name)
@@ -343,6 +359,8 @@ void header_ensure_member_types_exist(FILE *file, HTable *table, Decl **members)
 			case DECL_UNION:
 				header_ensure_member_types_exist(file, table, member->strukt.members);
 				break;
+			case DECL_BITSTRUCT:
+				break;
 			default:
 				UNREACHABLE
 		}
@@ -419,7 +437,7 @@ RETRY:
 			if (htable_get(table, type)) return;
 			{
 				Decl *decl = type->decl;
-				PRINTF("typedef struct %s__ %s;\n", decl_get_extname(decl), decl_get_extname(decl));
+				PRINTF("typedef %s %s__ %s;\n", struct_union_str(decl), decl_get_extname(decl), decl_get_extname(decl));
 				htable_set(table, type, type);
 				header_ensure_member_types_exist(file, table, decl->strukt.members);
 				PRINTF("%s %s__\n", struct_union_str(decl), decl->extname);
@@ -544,6 +562,7 @@ void header_gen(Module **modules, unsigned module_count)
 	FILE *file_types = fopen(filename_types, "w");
 	OUT(file_types, "#include <stdint.h>\n");
 	OUT(file_types, "#include <stddef.h>\n");
+	OUT(file_types, "#include <stdbool.h>\n");
 	OUT(file_types, "#ifndef __c3__\n");
 	OUT(file_types, "#define __c3__\n\n");
 	OUT(file_types, "typedef void* c3typeid_t;\n");

src/compiler/sema_decls.c

@@ -11,7 +11,7 @@
 static inline bool sema_analyse_func_macro(SemaContext *context, Decl *decl, AttributeDomain domain, bool *erase_decl);
 static inline bool sema_analyse_func(SemaContext *context, Decl *decl, bool *erase_decl);
 static inline bool sema_analyse_macro(SemaContext *context, Decl *decl, bool *erase_decl);
-static inline bool sema_analyse_signature(SemaContext *context, Signature *sig, TypeInfoId type_parent);
+static inline bool sema_analyse_signature(SemaContext *context, Signature *sig, TypeInfoId type_parent, bool is_export);
 static inline bool sema_analyse_main_function(SemaContext *context, Decl *decl);
 static inline bool sema_check_param_uniqueness_and_type(SemaContext *context, Decl **decls, Decl *current,
                                                         unsigned current_index, unsigned count);
@@ -27,6 +27,7 @@ static inline Decl *operator_in_module(SemaContext *c, Module *module, OperatorO
 static inline bool sema_analyse_operator_element_at(SemaContext *context, Decl *method);
 static inline bool sema_analyse_operator_element_set(SemaContext *context, Decl *method);
 static inline bool sema_analyse_operator_len(Decl *method, SemaContext *context);
+static bool sema_require_export_type(SemaContext *context, TypeInfo *type_info);
 static bool sema_check_operator_method_validity(SemaContext *context, Decl *method);
 static inline const char *method_name_by_decl(Decl *method_like);
 
@@ -229,6 +230,7 @@ static inline bool sema_analyse_struct_member(SemaContext *context, Decl *parent
 		sema_decl_stack_push(decl);
 	}
 
+	bool is_export = parent->is_export;
 	// Analysis depends on the underlying type.
 	switch (decl->decl_kind)
 	{
@@ -240,6 +242,7 @@ static inline bool sema_analyse_struct_member(SemaContext *context, Decl *parent
 			assert(type_infoptrzero(decl->var.type_info));
 			TypeInfo *type_info = type_infoptr(decl->var.type_info);
 			if (!sema_resolve_type_info(context, type_info, RESOLVE_TYPE_ALLOW_FLEXIBLE)) return decl_poison(decl);
+			if (is_export && !sema_require_export_type(context, type_info)) return decl_poison(decl);
 			Type *type = type_info->type;
 			switch (type_storage_type(type))
 			{
@@ -259,6 +262,7 @@ static inline bool sema_analyse_struct_member(SemaContext *context, Decl *parent
 		case DECL_STRUCT:
 		case DECL_UNION:
 		case DECL_BITSTRUCT:
+			decl->is_export = is_export;
 			if (!sema_analyse_decl(context, decl)) return false;
 			return true;
 		default:
@@ -945,7 +949,17 @@ ERROR:
 	return decl_poison(decl);
 }
 
-static inline bool sema_analyse_signature(SemaContext *context, Signature *sig, TypeInfoId type_parent)
+static bool sema_require_export_type(SemaContext *context, TypeInfo *type_info)
+{
+	Decl *decl = type_no_export(type_info->type);
+	if (!decl) return true;
+	SEMA_ERROR(type_info, "%s must also be an exported type, to make this work '%s' needs to be marked '@export'",
+	           type_quoted_error_string(type_info->type), decl->name);
+	SEMA_NOTE(decl, "The definition is here.");
+	return false;
+}
+
+static inline bool sema_analyse_signature(SemaContext *context, Signature *sig, TypeInfoId type_parent, bool is_export)
 {
 	Variadic variadic_type = sig->variadic;
 	Decl **params = sig->params;
@@ -963,6 +977,7 @@ static inline bool sema_analyse_signature(SemaContext *context, Signature *sig,
 		                            is_macro ? RESOLVE_TYPE_ALLOW_INFER
 		                                     : RESOLVE_TYPE_DEFAULT)) return false;
 		rtype = rtype_info->type;
+		if (is_export && !sema_require_export_type(context, rtype_info)) return false;
 		if (sig->attrs.nodiscard)
 		{
 			if (type_is_void(rtype))
@@ -993,10 +1008,12 @@ static inline bool sema_analyse_signature(SemaContext *context, Signature *sig,
 		return false;
 	}
 
+	TypeInfo *method_parent = type_infoptrzero(type_parent);
+	if (is_export && method_parent && !sema_require_export_type(context, method_parent)) return false;
+
 	// Fill in the type if the first parameter is lacking a type.
-	if (type_parent && params && params[0] && !params[0]->var.type_info)
+	if (method_parent && params && params[0] && !params[0]->var.type_info)
 	{
-		TypeInfo *method_parent = type_infoptr(type_parent);
 		if (!sema_resolve_type_info(context, method_parent,
 		                            is_macro ? RESOLVE_TYPE_MACRO_METHOD : RESOLVE_TYPE_FUNC_METHOD)) return false;
 		Decl *param = params[0];
@@ -1067,6 +1084,7 @@ static inline bool sema_analyse_signature(SemaContext *context, Signature *sig,
 			if (!sema_resolve_type_info(context, type_info,
 			                            is_macro ? RESOLVE_TYPE_ALLOW_INFER
 			                                     : RESOLVE_TYPE_DEFAULT)) return decl_poison(param);
+			if (is_export && !sema_require_export_type(context, type_info)) return false;
 			param->type = type_info->type;
 		}
 		switch (var_kind)
@@ -1181,7 +1199,7 @@ bool sema_analyse_function_signature(SemaContext *context, Decl *func_decl, Call
 	// Get param count and variadic type
 	Decl **params = signature->params;
 
-	if (!sema_analyse_signature(context, signature, func_decl->func_decl.type_parent)) return false;
+	if (!sema_analyse_signature(context, signature, func_decl->func_decl.type_parent, func_decl->is_export)) return false;
 
 	Variadic variadic_type = signature->variadic;
 	// Remove the last empty value.
@@ -3273,7 +3291,8 @@ static inline bool sema_analyse_macro(SemaContext *context, Decl *decl, bool *er
 
 	if (!sema_analyse_func_macro(context, decl, ATTR_MACRO, erase_decl)) return false;
 	if (*erase_decl) return true;
-	if (!sema_analyse_signature(context, &decl->func_decl.signature, decl->func_decl.type_parent)) return decl_poison(decl);
+	if (!sema_analyse_signature(context, &decl->func_decl.signature, decl->func_decl.type_parent,
+	                            false)) return decl_poison(decl);
 
 	if (!decl->func_decl.signature.is_at_macro && decl->func_decl.body_param && !decl->func_decl.signature.is_safemacro)
 	{

src/compiler/types.c

@@ -384,6 +384,59 @@ bool type_flat_is_boolintlike(Type *type)
 	return kind == TYPE_BOOL || (kind >= TYPE_INTEGER_FIRST && kind <= TYPE_INTEGER_LAST);
 }
 
+Decl *type_no_export(Type *type)
+{
+	type = type->canonical;
+	RETRY:
+	switch (type->type_kind)
+	{
+		case TYPE_POISONED:
+		case TYPE_UNTYPED_LIST:
+		case TYPE_WILDCARD:
+		case TYPE_MEMBER:
+		case TYPE_TYPEINFO:
+			return NULL;
+		case TYPE_VOID:
+		case TYPE_BOOL:
+		case ALL_INTS:
+		case ALL_FLOATS:
+		case TYPE_ANY:
+		case TYPE_INTERFACE:
+		case TYPE_ANYFAULT:
+		case TYPE_TYPEID:
+			return NULL;
+		case TYPE_POINTER:
+			type = type->pointer;
+			goto RETRY;
+		case TYPE_FUNC_PTR:
+			type = type->pointer;
+			FALLTHROUGH;
+		case TYPE_FUNC_RAW:
+		case TYPE_ENUM:
+		case TYPE_STRUCT:
+		case TYPE_UNION:
+		case TYPE_BITSTRUCT:
+		case TYPE_FAULTTYPE:
+		case TYPE_DISTINCT:
+			if (type->decl->is_export) return NULL;
+			return type->decl;
+		case TYPE_SLICE:
+		case TYPE_TYPEDEF:
+		case TYPE_ARRAY:
+		case TYPE_FLEXIBLE_ARRAY:
+		case TYPE_INFERRED_ARRAY:
+			type = type->array.base;
+			goto RETRY;
+		case TYPE_VECTOR:
+		case TYPE_INFERRED_VECTOR:
+			return NULL;
+		case TYPE_OPTIONAL:
+			type = type->optional;
+			goto RETRY;
+	}
+	UNREACHABLE
+}
+
 
 bool type_is_int128(Type *type)
 {

test/test_suite/debug_symbols/defer_macro.c3t

@@ -83,11 +83,11 @@ distinct Color = float[<4>];
 const Color BLACK = {0, 0, 0, 1};
 const Color WHITE = {1, 1, 1, 1};
 
-struct Arena {
+struct Arena @export {
   usz cursor;
 }
 
-struct Arena_Cursor {
+struct Arena_Cursor @export {
   Arena* arena;
   usz cursor;
 }
@@ -690,11 +690,11 @@ no_match:                                         ; preds = %compare
 !106 = !{!12}
 !107 = !DILocalVariable(name: "scratch", scope: !108, file: !5, line: 110, type: !109, align: 8)
 !108 = distinct !DISubprogram(name: "@scratch", linkageName: "@scratch", scope: !5, file: !5, line: 109, scopeLine: 109, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition, unit:
-!109 = !DICompositeType(tag: DW_TAG_structure_type, name: "Arena_Cursor", scope: !5, file: !5, line: 88, size: 128, align: 64, elements: !110, identifier: "foo.Arena_Cursor")
+!109 = !DICompositeType(tag: DW_TAG_structure_type, name: "Arena_Cursor", scope: !5, file: !5, line: 88, size: 128, align: 64, elements: !110, identifier: "foo_Arena_Cursor")
 !110 = !{!111, !116}
 !111 = !DIDerivedType(tag: DW_TAG_member, name: "arena", scope: !109, file: !5, line: 89, baseType: !112, size: 64, align: 64)
 !112 = !DIDerivedType(tag: DW_TAG_pointer_type, name: "Arena*", baseType: !113, size: 64, align: 64, dwarfAddressSpace: 0)
-!113 = !DICompositeType(tag: DW_TAG_structure_type, name: "Arena", scope: !5, file: !5, line: 84, size: 64, align: 64, elements: !114, identifier: "foo.Arena")
+!113 = !DICompositeType(tag: DW_TAG_structure_type, name: "Arena", scope: !5, file: !5, line: 84, size: 64, align: 64, elements: !114, identifier: "foo_Arena")
 !114 = !{!115}
 !115 = !DIDerivedType(tag: DW_TAG_member, name: "cursor", scope: !113, file: !5, line: 85, baseType: !44, size: 64, align: 64)
 !116 = !DIDerivedType(tag: DW_TAG_member, name: "cursor", scope: !109, file: !5, line: 90, baseType: !44, size: 64, align: 64, offset: 64)

test/test_suite/visibility/export_property.c3

@@ -0,0 +1,41 @@
+fn Abcd test(Test a) @export
+{
+	return Abcd.ABC;
+}
+
+fn void test2(Abc a) @export // #error: must also be an exported type
+{
+}
+
+fault Abcd @export
+{
+	ABC,
+	EFG
+}
+enum Abc
+{
+	ABC,
+	DEF
+}
+struct Test @export
+{
+	struct
+	{
+		int a;
+		int b;
+	}
+	bitstruct : int
+	{
+		int fa : 1..6;
+	}
+	int[*] x;
+
+}
+
+struct Test2 @export
+{
+	struct
+	{
+		Abc d; // #error: must also be an exported type
+	}
+}