Commit 461382ae941e235ad75a6b3d00e05e5369baa98a | zig

author	Andrew Kelley <andrew@ziglang.org> 2019-05-31 01:08:16-04:00
committer	Andrew Kelley <andrew@ziglang.org> 2019-05-31 01:08:16-04:00
log	461382ae941e235ad75a6b3d00e05e5369baa98a
tree	b449441093bf6c26caa97959c2d449a137b0cc23
parent	8aba0643a55e4a67c0e7e01c1946900164514f4c
signature	Commit is signed but in an unrecognized format.

no-copy semantics for function call init var and literal

```zig
export fn entry() void {
    var x = foo();
}
const Foo = struct {
    x: i32,
};
fn foo() Foo {
    return Foo{
        .x = 1234,
    };
}
```

```llvm
define void @entry() #2 !dbg !35 {
Entry:
  %x = alloca %Foo, align 4
  call fastcc void @foo(%Foo* sret %x), !dbg !45
  call void @llvm.dbg.declare(metadata %Foo* %x, metadata !39, metadata !DIExpression()), !dbg !46
  ret void, !dbg !47
}
define internal fastcc void @foo(%Foo* nonnull sret) unnamed_addr #2 !dbg !48 {
Entry:
  %1 = bitcast %Foo* %0 to i8*, !dbg !52
  call void @llvm.memcpy.p0i8.p0i8.i64(i8* align 4 %1, i8* align 4 bitcast (%Foo* @0 to i8*), i64 4, i1 false), !dbg !52
  ret void, !dbg !52
}
```

1 files changed, 6 insertions(+), 3 deletions(-)

src
- ir.cpp

src/ir.cpp+6-3

...	...	@@ -14365,11 +14365,11 @@ static IrInstruction ir_resolve_result(IrAnalyze ira, ResultLoc *result_loc, Z
14365	14365	assert(result_loc->source_instruction->id == IrInstructionIdAllocaSrc);
14366	14366	IrInstructionAllocaSrc *alloca_src =
14367	14367	reinterpret_cast<IrInstructionAllocaSrc *>(result_loc->source_instruction);
14368		bool is_comptime = value != nullptr && value->value.special != ConstValSpecialRuntime &&
14369		result_loc_var->var->gen_is_const;
14370	14368	if (alloca_src->base.child == nullptr) {
14371	14369	uint32_t align = 0; // TODO
14372	14370	bool force_comptime = false; // TODO
	14371	bool is_comptime = value != nullptr && value->value.special != ConstValSpecialRuntime &&
	14372	result_loc_var->var->gen_is_const;
14373	14373	IrInstruction *alloca_gen;
14374	14374	if (is_comptime) {
14375	14375	alloca_gen = ir_get_ref(ira, result_loc->source_instruction, value, true, false);
...	...	@@ -14378,10 +14378,13 @@ static IrInstruction ir_resolve_result(IrAnalyze ira, ResultLoc *result_loc, Z
14378	14378	alloca_src->name_hint, force_comptime);
14379	14379	}
14380	14380	alloca_src->base.child = alloca_gen;
	14381	return is_comptime ? nullptr : alloca_src->base.child;
14381	14382	}
14382		return is_comptime ? nullptr : alloca_src->base.child;
	14383	return nullptr;
14383	14384	}
14384	14385	case ResultLocIdReturn: {
	14386	bool is_comptime = value != nullptr && value->value.special != ConstValSpecialRuntime;
	14387	if (is_comptime) return nullptr;
14385	14388	ZigType *ptr_return_type = get_pointer_to_type(ira->codegen, ira->explicit_return_type, false);
14386	14389	return ir_build_return_ptr(ira, result_loc->source_instruction, ptr_return_type);
14387	14390	}