Commit 9902b604cb01072d4599035b59724731cf03fdbc | zig

author	LemonBoy <thatlemon@gmail.com> 2019-04-28 12:45:50+02:00
committer	Andrew Kelley <andrew@ziglang.org> 2019-04-28 13:13:42-04:00
log	9902b604cb01072d4599035b59724731cf03fdbc
tree	67d5deb790c0abca47b60b95c729dc0e10b93a38
parent	205e501e42b9a2e1d35afa0873311165100863ae

Fix generation of container initializers

The code creates temporary ConstExprValue with global_refs set to
nullptr and that's carried over to the final value. Doing so prevents
the deduplication mechanism to work correctly, causing all sorts of
runtime crashes.

Fixes #1636
Fixes #1608 (Even though it was already fixed by #1991)

2 files changed, 26 insertions(+), 7 deletions(-)

src
- ir.cpp
test
- stage1
  - behavior
    struct.zig

src/ir.cpp+6-5

...	...	@@ -9931,6 +9931,7 @@ static void ir_add_alloca(IrAnalyze ira, IrInstruction instruction, ZigType *t
9931	9931
9932	9932	static void copy_const_val(ConstExprValue dest, ConstExprValue src, bool same_global_refs) {
9933	9933	ConstGlobalRefs *global_refs = dest->global_refs;
	9934	assert(!same_global_refs \|\| src->global_refs != nullptr);
9934	9935	dest = src;
9935	9936	if (!same_global_refs) {
9936	9937	dest->global_refs = global_refs;
...	...	@@ -17468,6 +17469,7 @@ static IrInstruction ir_analyze_container_init_fields(IrAnalyze ira, IrInstruc
17468	17469	ConstExprValue const_val = {};
17469	17470	const_val.special = ConstValSpecialStatic;
17470	17471	const_val.type = container_type;
	17472	// const_val.global_refs = allocate<ConstGlobalRefs>(1);
17471	17473	const_val.data.x_struct.fields = create_const_vals(actual_field_count);
17472	17474	for (size_t i = 0; i < instr_field_count; i += 1) {
17473	17475	IrInstructionContainerInitFieldsField *field = &fields[i];
...	...	@@ -17531,7 +17533,7 @@ static IrInstruction ir_analyze_container_init_fields(IrAnalyze ira, IrInstruc
17531	17533	if (const_val.special == ConstValSpecialStatic) {
17532	17534	IrInstruction *result = ir_const(ira, instruction, nullptr);
17533	17535	ConstExprValue *out_val = &result->value;
17534		copy_const_val(out_val, &const_val, true);
	17536	copy_const_val(out_val, &const_val, false);
17535	17537	out_val->type = container_type;
17536	17538
17537	17539	for (size_t i = 0; i < instr_field_count; i += 1) {
...	...	@@ -17603,6 +17605,7 @@ static IrInstruction ir_analyze_instruction_container_init_list(IrAnalyze ira,
17603	17605	ConstExprValue const_val = {};
17604	17606	const_val.special = ConstValSpecialStatic;
17605	17607	const_val.type = fixed_size_array_type;
	17608	// const_val.global_refs = allocate<ConstGlobalRefs>(1);
17606	17609	const_val.data.x_array.data.s_none.elements = create_const_vals(elem_count);
17607	17610
17608	17611	bool is_comptime = ir_should_inline(ira->new_irb.exec, instruction->base.scope);
...	...	@@ -17639,8 +17642,6 @@ static IrInstruction ir_analyze_instruction_container_init_list(IrAnalyze ira,
17639	17642	if (const_val.special == ConstValSpecialStatic) {
17640	17643	IrInstruction *result = ir_const(ira, &instruction->base, nullptr);
17641	17644	ConstExprValue *out_val = &result->value;
17642		// Make sure to pass same_global_refs=false here in order not to
17643		// zero the global_refs field for `result` (#1608)
17644	17645	copy_const_val(out_val, &const_val, false);
17645	17646	result->value.type = fixed_size_array_type;
17646	17647	for (size_t i = 0; i < elem_count; i += 1) {
...	...	@@ -21319,7 +21320,7 @@ static IrInstruction ir_align_cast(IrAnalyze ira, IrInstruction *target, uint3
21319	21320	}
21320	21321
21321	21322	IrInstruction *result = ir_const(ira, target, result_type);
21322		copy_const_val(&result->value, val, false);
	21323	copy_const_val(&result->value, val, true);
21323	21324	result->value.type = result_type;
21324	21325	return result;
21325	21326	}
...	...	@@ -21389,7 +21390,7 @@ static IrInstruction ir_analyze_ptr_cast(IrAnalyze ira, IrInstruction *source_
21389	21390	}
21390	21391
21391	21392	IrInstruction *result = ir_const(ira, source_instr, dest_type);
21392		copy_const_val(&result->value, val, false);
	21393	copy_const_val(&result->value, val, true);
21393	21394	result->value.type = dest_type;
21394	21395
21395	21396	// Keep the bigger alignment, it can only help-

test/stage1/behavior/struct.zig+20-2

...	...	@@ -2,8 +2,7 @@ const std = @import("std");
2	2	const expect = std.testing.expect;
3	3	const expectEqualSlices = std.testing.expectEqualSlices;
4	4	const builtin = @import("builtin");
5		const maxInt = std.math.maxInt;
6
	5	const maxInt = std.math.maxInt;
7	6	const StructWithNoFields = struct {
8	7	fn add(a: i32, b: i32) i32 {
9	8	return a + b;
...	...	@@ -505,3 +504,22 @@ test "packed struct with u0 field access" {
505	504	var s = S{ .f0 = 0 };
506	505	comptime expect(s.f0 == 0);
507	506	}
	507
	508	const S0 = struct{
	509	bar: S1,
	510
	511	pub const S1 = struct{
	512	value: u8,
	513	};
	514
	515	fn init() @This() {
	516	return S0{ .bar = S1{ .value = 123 } };
	517	}
	518	};
	519
	520	var g_foo: S0 = S0.init();
	521
	522	test "access to global struct fields" {
	523	g_foo.bar.value = 42;
	524	expect(g_foo.bar.value == 42);
	525	}