CGBuilderTy &Builder,

const bool UsePointerValue) {

// Clang stores the sret pointer provided by the caller in a static alloca.

// Use DW_OP_deref to tell the debugger to load the pointer and treat it as

// the address of the variable.

if (UsePointerValue) {

assert(std::find(Expr.begin(), Expr.end(), llvm::dwarf::DW_OP_deref) ==

Expr.end() &&

"Debug info already contains DW_OP_deref.");

Expr.push_back(llvm::dwarf::DW_OP_deref);

}

CGBuilderTy &Builder,

const bool UsePointerValue) {

return EmitDeclare(VD, Storage, llvm::None, Builder, UsePointerValue);

llvm::DILocalVariable *

EmitDeclareOfAutoVariable(const VarDecl *Decl, llvm::Value *AI,

CGBuilderTy &Builder,

const bool UsePointerValue = false);

CGBuilderTy &Builder,

const bool UsePointerValue = false);

bool NRVO = getLangOpts().ElideConstructors && D.isNRVOVariable();

Address DebugAddr = address;

bool UsePointerValue = NRVO && ReturnValuePointer.isValid();

// If NRVO, use a pointer to the return address.

if (UsePointerValue)

DebugAddr = ReturnValuePointer;

(void)DI->EmitDeclareOfAutoVariable(&D, DebugAddr.getPointer(), Builder,

UsePointerValue);

if (!CurFnInfo->getReturnInfo().getIndirectByVal()) {

ReturnValuePointer =

CreateDefaultAlignTempAlloca(Int8PtrTy, "result.ptr");

Builder.CreateStore(Builder.CreatePointerBitCastOrAddrSpaceCast(

ReturnValue.getPointer(), Int8PtrTy),

ReturnValuePointer);

}

ReturnValuePointer = Address(Addr, getPointerAlign());

/// ReturnValuePointer - The temporary alloca to hold a pointer to sret.

/// This is invalid if sret is not in use.

Address ReturnValuePointer = Address::invalid();

// CHECK: store [[B]]* {{%.*}}, [[B]]** [[X]]

// CHECK: call void @_ZN5test312test1_helperEv([[B]]* sret [[TEMP]])

// CHECK: store [[B]]* {{%.*}}, [[B]]** [[X]]

// CHECK: call void @_ZN5test312test3_helperEv([[B]]* sret [[TEMP]])

struct Foo {

Foo() = default;

Foo(Foo &&other) { x = other.x; }

int x;

};

void some_function(int);

Foo getFoo() {

Foo foo;

foo.x = 41;

some_function(foo.x);

return foo;

}

int main() {

Foo bar = getFoo();

return bar.x;

}

void some_function(int) {}

struct string2 {

string2() = default;

string2(string2 &&other) { i = other.i; }

int i;

};

string2 get_string2() {

string2 result;

result.i = 5;

some_function(result.i);

// Test that the debugger can get the value of result after another

// function is called.

// DEBUGGER: break 35

return result;

}

int main() {

get_string();

get_string2();

}

struct string {

string() {}

string(int i) : i(i) {}

~string() {}

int i = 0;

};

string get_string() {

string unused;

string result = 3;

__debugbreak();

return result;

}

void some_function(int) {}

struct string2 {

string2() = default;

string2(string2 &&other) { i = other.i; }

int i;

};

string2 get_string2() {

string2 result;

result.i = 5;

some_function(result.i);

// Test that the debugger can get the value of result after another

// function is called.

__debugbreak();

return result;

}

int main() {

get_string();

get_string2();

}

bool Deref = false;

if (VI.Expr) {

// If there is one DW_OP_deref element, use offset of 0 and keep going.

if (VI.Expr->getNumElements() == 1 &&

VI.Expr->getElement(0) == llvm::dwarf::DW_OP_deref)

Deref = true;

else if (!VI.Expr->extractIfOffset(ExprOffset))

}

if (Deref)

Var.UseReferenceType = true;

source_filename = "t.cpp"

target datalayout = "e-m:w-i64:64-f80:128-n8:16:32:64-S128"

target triple = "x86_64-pc-windows-msvc19.16.27030"

%struct.Foo = type { i32 }

define dso_local void @"?some_function@@YAXH@Z"(i32) #0 !dbg !8 {

entry:

%.addr = alloca i32, align 4

store i32 %0, i32* %.addr, align 4

call void @llvm.dbg.declare(metadata i32* %.addr, metadata !12, metadata !DIExpression()), !dbg !13

ret void, !dbg !13

}

declare void @llvm.dbg.declare(metadata, metadata, metadata) #1

define dso_local void @"?GetFoo@@YA?AUFoo@@XZ"(%struct.Foo* noalias sret %agg.result) #0 !dbg !14 {

entry:

%result.ptr = alloca i8*, align 8

%0 = bitcast %struct.Foo* %agg.result to i8*

store i8* %0, i8** %result.ptr, align 8

call void @llvm.dbg.declare(metadata i8** %result.ptr, metadata !28, metadata !DIExpression(DW_OP_deref)), !dbg !29

%x = getelementptr inbounds %struct.Foo, %struct.Foo* %agg.result, i32 0, i32 0, !dbg !30

store i32 41, i32* %x, align 4, !dbg !30

%x1 = getelementptr inbounds %struct.Foo, %struct.Foo* %agg.result, i32 0, i32 0, !dbg !31

%1 = load i32, i32* %x1, align 4, !dbg !31

call void @"?some_function@@YAXH@Z"(i32 %1), !dbg !31

ret void, !dbg !32

}

define dso_local i32 @main() #2 !dbg !33 {

entry:

%retval = alloca i32, align 4

%bar = alloca %struct.Foo, align 4

store i32 0, i32* %retval, align 4

call void @llvm.dbg.declare(metadata %struct.Foo* %bar, metadata !36, metadata !DIExpression()), !dbg !37

call void @"?GetFoo@@YA?AUFoo@@XZ"(%struct.Foo* sret %bar), !dbg !37

%x = getelementptr inbounds %struct.Foo, %struct.Foo* %bar, i32 0, i32 0, !dbg !38

%0 = load i32, i32* %x, align 4, !dbg !38

ret i32 %0, !dbg !38

}

attributes #0 = { noinline nounwind optnone uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }

attributes #1 = { nounwind readnone speculatable }

attributes #2 = { noinline norecurse nounwind optnone uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }

!llvm.dbg.cu = !{!0}

!llvm.module.flags = !{!3, !4, !5, !6}

!llvm.ident = !{!7}

!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 9.0.0 (https://github.com/llvm/llvm-project.git c19ebebac4bf853e77a69c74abe9f7fce98c1d17)", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None)

!1 = !DIFile(filename: "t.cpp", directory: "C:\5Csrc\5Ctesting\5Cnrvo", checksumkind: CSK_MD5, checksum: "52a5a20c02c102dfd255d5615680a8bd")

!2 = !{}

!3 = !{i32 2, !"CodeView", i32 1}

!4 = !{i32 2, !"Debug Info Version", i32 3}

!5 = !{i32 1, !"wchar_size", i32 2}

!6 = !{i32 7, !"PIC Level", i32 2}

!7 = !{!"clang version 9.0.0 (https://github.com/llvm/llvm-project.git c19ebebac4bf853e77a69c74abe9f7fce98c1d17)"}

!8 = distinct !DISubprogram(name: "some_function", linkageName: "?some_function@@YAXH@Z", scope: !1, file: !1, line: 13, type: !9, scopeLine: 13, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !2)

!9 = !DISubroutineType(types: !10)

!10 = !{null, !11}

!11 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)

!12 = !DILocalVariable(arg: 1, scope: !8, file: !1, line: 13, type: !11)

!13 = !DILocation(line: 13, scope: !8)

!14 = distinct !DISubprogram(name: "GetFoo", linkageName: "?GetFoo@@YA?AUFoo@@XZ", scope: !1, file: !1, line: 15, type: !15, scopeLine: 15, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !2)

!15 = !DISubroutineType(types: !16)

!16 = !{!17}

!17 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "Foo", file: !1, line: 1, size: 32, flags: DIFlagTypePassByReference | DIFlagNonTrivial, elements: !18, identifier: ".?AUFoo@@")

!18 = !{!19, !20, !24}

!19 = !DIDerivedType(tag: DW_TAG_member, name: "x", scope: !17, file: !1, line: 4, baseType: !11, size: 32)

!20 = !DISubprogram(name: "Foo", scope: !17, file: !1, line: 2, type: !21, scopeLine: 2, flags: DIFlagPrototyped, spFlags: 0)

!21 = !DISubroutineType(types: !22)

!22 = !{null, !23}

!23 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !17, size: 64, flags: DIFlagArtificial | DIFlagObjectPointer)

!24 = !DISubprogram(name: "Foo", scope: !17, file: !1, line: 3, type: !25, scopeLine: 3, flags: DIFlagPrototyped, spFlags: 0)

!25 = !DISubroutineType(types: !26)

!26 = !{null, !23, !27}

!27 = !DIDerivedType(tag: DW_TAG_rvalue_reference_type, baseType: !17, size: 64)

!28 = !DILocalVariable(name: "foo", scope: !14, file: !1, line: 17, type: !17)

!29 = !DILocation(line: 17, scope: !14)

!30 = !DILocation(line: 18, scope: !14)

!31 = !DILocation(line: 19, scope: !14)

!32 = !DILocation(line: 21, scope: !14)

!33 = distinct !DISubprogram(name: "main", scope: !1, file: !1, line: 23, type: !34, scopeLine: 23, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !2)

!34 = !DISubroutineType(types: !35)

!35 = !{!11}

!36 = !DILocalVariable(name: "bar", scope: !33, file: !1, line: 24, type: !17)

!37 = !DILocation(line: 24, scope: !33)

!38 = !DILocation(line: 25, scope: !33)