| author |  LemonBoy <thatlemon@gmail.com> 2019-11-14 10:20:57+01:00 |
| committer |  Andrew Kelley <andrew@ziglang.org> 2019-11-14 17:07:20+00:00 |
| log | a11da377347aea1085d3b43726040993952122c9 |
| tree | 3c5e61dd1ff0ff0d51f4d163ade020a3a8dd8328 |
| parent | d89f39d71949c85b26f2ccd4071c9445aa8b6d7c |
Update discriminant value also for zero-sized unions
Fixes #36812 files changed, 39 insertions(+), 13 deletions(-)
src- test
- stage1
- behavior
src/codegen.cpp+24-9
| ... | ... | @@ -4351,17 +4351,32 @@ static LLVMValueRef ir_render_union_field_ptr(CodeGen *g, IrExecutable *executab |
| 4351 | 4351 | TypeUnionField *field = instruction->field; |
| 4352 | 4352 | |
| 4353 | 4353 | if (!type_has_bits(field->type_entry)) { |
| 4354 | if (union_type->data.unionation.gen_tag_index == SIZE_MAX) { | |
| 4354 | ZigType *tag_type = union_type->data.unionation.tag_type; | |
| 4355 | if (!instruction->initializing || !type_has_bits(tag_type)) | |
| 4355 | 4356 | return nullptr; |
| 4357 | ||
| 4358 | // The field has no bits but we still have to change the discriminant | |
| 4359 | // value here | |
| 4360 | LLVMValueRef union_ptr = ir_llvm_value(g, instruction->union_ptr); | |
| 4361 | ||
| 4362 | LLVMTypeRef tag_type_ref = get_llvm_type(g, tag_type); | |
| 4363 | LLVMValueRef tag_field_ptr = nullptr; | |
| 4364 | if (union_type->data.unionation.gen_field_count == 0) { | |
| 4365 | assert(union_type->data.unionation.gen_tag_index == SIZE_MAX); | |
| 4366 | // The whole union is collapsed into the discriminant | |
| 4367 | tag_field_ptr = LLVMBuildBitCast(g->builder, union_ptr, | |
| 4368 | LLVMPointerType(tag_type_ref, 0), ""); | |
| 4369 | } else { | |
| 4370 | assert(union_type->data.unionation.gen_tag_index != SIZE_MAX); | |
| 4371 | tag_field_ptr = LLVMBuildStructGEP(g->builder, union_ptr, | |
| 4372 | union_type->data.unionation.gen_tag_index, ""); | |
| 4356 | 4373 | } |
| 4357 | if (instruction->initializing) { | |
| 4358 | LLVMValueRef union_ptr = ir_llvm_value(g, instruction->union_ptr); | |
| 4359 | LLVMValueRef tag_field_ptr = LLVMBuildStructGEP(g->builder, union_ptr, | |
| 4360 | union_type->data.unionation.gen_tag_index, ""); | |
| 4361 | LLVMValueRef tag_value = bigint_to_llvm_const(get_llvm_type(g, union_type->data.unionation.tag_type), | |
| 4362 | &field->enum_field->value); | |
| 4363 | gen_store_untyped(g, tag_value, tag_field_ptr, 0, false); | |
| 4364 | } | |
| 4374 | ||
| 4375 | LLVMValueRef tag_value = bigint_to_llvm_const(tag_type_ref, | |
| 4376 | &field->enum_field->value); | |
| 4377 | assert(tag_field_ptr != nullptr); | |
| 4378 | gen_store_untyped(g, tag_value, tag_field_ptr, 0, false); | |
| 4379 | ||
| 4365 | 4380 | return nullptr; |
| 4366 | 4381 | } |
| 4367 | 4382 |
test/stage1/behavior/union.zig+15-4
| ... | ... | @@ -110,7 +110,7 @@ fn doTest() void { |
| 110 | 110 | } |
| 111 | 111 | |
| 112 | 112 | fn bar(value: Payload) i32 { |
| 113 | expect(@as(Letter,value) == Letter.A); | |
| 113 | expect(@as(Letter, value) == Letter.A); | |
| 114 | 114 | return switch (value) { |
| 115 | 115 | Payload.A => |x| return x - 1244, |
| 116 | 116 | Payload.B => |x| if (x == 12.34) @as(i32, 20) else 21, |
| ... | ... | @@ -208,7 +208,7 @@ test "cast union to tag type of union" { |
| 208 | 208 | } |
| 209 | 209 | |
| 210 | 210 | fn testCastUnionToTagType(x: TheUnion) void { |
| 211 | expect(@as(TheTag,x) == TheTag.B); | |
| 211 | expect(@as(TheTag, x) == TheTag.B); | |
| 212 | 212 | } |
| 213 | 213 | |
| 214 | 214 | test "cast tag type of union to union" { |
| ... | ... | @@ -558,16 +558,27 @@ test "anonymous union literal syntax" { |
| 558 | 558 | }; |
| 559 | 559 | |
| 560 | 560 | fn doTheTest() void { |
| 561 | var i: Number = .{.int = 42}; | |
| 561 | var i: Number = .{ .int = 42 }; | |
| 562 | 562 | var f = makeNumber(); |
| 563 | 563 | expect(i.int == 42); |
| 564 | 564 | expect(f.float == 12.34); |
| 565 | 565 | } |
| 566 | 566 | |
| 567 | 567 | fn makeNumber() Number { |
| 568 | return .{.float = 12.34}; | |
| 568 | return .{ .float = 12.34 }; | |
| 569 | 569 | } |
| 570 | 570 | }; |
| 571 | 571 | S.doTheTest(); |
| 572 | 572 | comptime S.doTheTest(); |
| 573 | 573 | } |
| 574 | ||
| 575 | test "update the tag value for zero-sized unions" { | |
| 576 | const S = union(enum) { | |
| 577 | U0: void, | |
| 578 | U1: void, | |
| 579 | }; | |
| 580 | var x = S{ .U0 = {} }; | |
| 581 | expect(x == .U0); | |
| 582 | x = S{ .U1 = {} }; | |
| 583 | expect(x == .U1); | |
| 584 | } |