- Compiler segfault when accessing member of number cast to bitstruct #2516.

- Additional fix to #2515
- Compiler assert when getting a member of a `bitstruct : char @bigendian` #2517.

releasenotes.md

@@ -9,7 +9,9 @@
 - Bug in `io::write_using_write_byte`.
 - Bitstruct value cannot be used to index a const array in compile time. #2512
 - Compiler fails to stop error print in recursive macro, and also prints unnecessary "inline at" #2513.
-- Bitstruct truncated constant error escapes `$defined` #2515
+- Bitstruct truncated constant error escapes `$defined` #2515.
+- Compiler segfault when accessing member of number cast to bitstruct #2516.
+- Compiler assert when getting a member of a `bitstruct : char @bigendian` #2517.
 
 ### Stdlib changes
 

src/compiler/sema_decls.c

@@ -1060,6 +1060,11 @@ static bool sema_analyse_bitstruct(SemaContext *context, Decl *decl, bool *erase
 	DEBUG_LOG("Beginning analysis of %s.", decl->name ? decl->name : ".anon");
 	if (!sema_resolve_type_info(context, decl->strukt.container_type, RESOLVE_TYPE_DEFAULT)) return false;
 	Type *type = type_flatten(decl->strukt.container_type->type->canonical);
+	if (type_size(type) == 1)
+	{
+		decl->strukt.big_endian = false;
+		decl->strukt.little_endian = false;
+	}
 	Type *base_type = type->type_kind == TYPE_ARRAY ? type_flatten(type->array.base) : type;
 	if (!type_is_integer(base_type))
 	{

src/compiler/sema_expr.c

@@ -12046,18 +12046,20 @@ bool sema_cast_const(Expr *expr)
 		{
 			Expr *parent = expr->access_resolved_expr.parent;
 			Type *flat = type_flatten(parent->type);
+			if (!sema_cast_const(parent)) return false;
 			switch (flat->type_kind)
 			{
 				case TYPE_UNION:
 				case TYPE_UNTYPED_LIST:
-				case TYPE_BITSTRUCT:
 				case TYPE_STRUCT:
 					break;
+				case TYPE_BITSTRUCT:
+					if (!expr_is_const_initializer(parent)) return false;
+					break;
 				default:
 					return false;
 			}
-			if (!sema_cast_const(expr->access_resolved_expr.parent)) return false;
+			if (!sema_expr_fold_to_member(expr, parent, expr->access_resolved_expr.ref)) return false;
-			if (!sema_expr_fold_to_member(expr, expr->access_resolved_expr.parent, expr->access_resolved_expr.ref)) return false;
 			return true;
 		}
 		case EXPR_SLICE:

src/compiler/sema_initializers.c

@@ -580,7 +580,7 @@ static inline bool sema_expr_analyse_initializer(SemaContext *context, Type *ass
 	// 1. Designated initializer is separately evaluated.
 	if (expr->expr_kind == EXPR_DESIGNATED_INITIALIZER_LIST)
 	{
-		return sema_expr_analyse_designated_initializer(context, assigned_type, flattened, expr,NULL);
+		return sema_expr_analyse_designated_initializer(context, assigned_type, flattened, expr, no_match_ref);
 	}
 
 	if (expr->expr_kind == EXPR_CONST)

test/test_suite/bitstruct/big_endian_char.c3t

@@ -0,0 +1,16 @@
+bitstruct Instruction : char @bigendian
+{
+	ushort count : 4..7;
+}
+
+bitstruct Instruction2 : char @littleendian
+{
+	ushort count : 4..7;
+}
+
+fn int main(String[] args)
+{
+	Instruction a;
+	Instruction2 b;
+	return a.count;
+}

test/test_suite/bitstruct/bitrstruct_defined.c3t

@@ -4,3 +4,4 @@ bitstruct Test : char
 }
 
 $assert !$defined((Test){123});
+$assert !$defined((Test){.type = 123});

test/test_suite/bitstruct/cast_bitstruct_as_const_value_fail.c3

@@ -0,0 +1,8 @@
+bitstruct Test : char
+{
+	char type : 0..2;
+}
+
+const TEST = ((Test)char.max).type; // #error: This expression cannot be evaluated at compile
+
+fn int main() => 0;