Commit 6d2f103bfb8931e2e65ca7f79d62389b69781492 | zig

author	LemonBoy <thatlemon@gmail.com> 2020-10-25 11:25:02+01:00
committer	Veikka Tuominen <git@vexu.eu> 2020-10-28 21:13:32+02:00
log	6d2f103bfb8931e2e65ca7f79d62389b69781492
tree	f7f6d1fbbaffea1f1cfe9d743008c0e6e977424a
parent	1a171a143aaa1be843b6f028cbb8e82aaec79e2c

stage1: Fix crash in comptime struct value copy

Comptime fields are never materialized in the ZigValue so pay attention
when iterating over the fields array.

Fixes #6800

2 files changed, 30 insertions(+), 1 deletions(-)

src
- stage1
  - analyze.cpp
test
- stage1
  - behavior
    tuple.zig

src/stage1/analyze.cpp+12-1

 @@ -5686,7 +5686,13 @@ static bool can_mutate_comptime_var_state(ZigValue *value) {
             zig_unreachable();
         case ZigTypeIdStruct:
             for (uint32_t i = 0; i < value->type->data.structure.src_field_count; i += 1) {
-                if (can_mutate_comptime_var_state(value->data.x_struct.fields[i]))
+                TypeStructField *type_struct_field = value->type->data.structure.fields[i];
+                ZigValue *field_value = type_struct_field->is_comptime ?
+                        type_struct_field->init_val :
+                        value->data.x_struct.fields[i];
+                if (can_mutate_comptime_var_state(field_value))
                     return true;
             }
             return false;
 @@ -9690,6 +9696,11 @@ void copy_const_val(CodeGen *g, ZigValue *dest, ZigValue *src) {
     if (dest->type->id == ZigTypeIdStruct) {
         dest->data.x_struct.fields = alloc_const_vals_ptrs(g, dest->type->data.structure.src_field_count);
         for (size_t i = 0; i < dest->type->data.structure.src_field_count; i += 1) {
+            TypeStructField *type_struct_field = dest->type->data.structure.fields[i];
+            // comptime-known values are stored in the field init_val inside
+            // the struct type.
+            if (type_struct_field->is_comptime)
+                continue;
             copy_const_val(g, dest->data.x_struct.fields[i], src->data.x_struct.fields[i]);
             dest->data.x_struct.fields[i]->parent.id = ConstParentIdStruct;
             dest->data.x_struct.fields[i]->parent.data.p_struct.struct_val = dest;

test/stage1/behavior/tuple.zig+18

...	@@ -93,3 +93,21 @@ test "pass tuple to comptime var parameter" {	...	@@ -93,3 +93,21 @@ test "pass tuple to comptime var parameter" {
93	S.doTheTest();	93	S.doTheTest();
94	comptime S.doTheTest();	94	comptime S.doTheTest();
95	}	95	}
		96
		97	test "tuple initializer for var" {
		98	const S = struct {
		99	fn doTheTest() void {
		100	const Bytes = struct {
		101	id: usize,
		102	};
		103
		104	var tmp = .{
		105	.id = @as(usize, 2),
		106	.name = Bytes{ .id = 20 },
		107	};
		108	}
		109	};
		110
		111	S.doTheTest();
		112	comptime S.doTheTest();
		113	}