Skip to content

Commit

Permalink
[CodeView] Add support for emitting S_UDT for typedefs
Browse files Browse the repository at this point in the history 
Emit a S_UDT record for typedefs.  We still need to do something for
class types.

Differential Revision: http://reviews.llvm.org/D21149

llvm-svn: 272813
  • Loading branch information
@majnemer
majnemer committed Jun 15, 2016
1 parent cc70da3 commit 3128b10
Show file tree
Hide file tree
Showing 4 changed files with 165 additions and 4 deletions.
87 changes: 83 additions & 4 deletions llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
View file
Expand Up @@ -253,12 +253,20 @@ void CodeViewDebug::endModule() {
emitDebugInfoForFunction(P.first, P.second);

// Emit global variable debug information.
setCurrentSubprogram(nullptr);
emitDebugInfoForGlobals();

// Switch back to the generic .debug$S section after potentially processing
// comdat symbol sections.
switchToDebugSectionForSymbol(nullptr);

// Emit UDT records for any types used by global variables.
if (!GlobalUDTs.empty()) {
MCSymbol *SymbolsEnd = beginCVSubsection(ModuleSubstreamKind::Symbols);
emitDebugInfoForUDTs(GlobalUDTs);
endCVSubsection(SymbolsEnd);
}

// This subsection holds a file index to offset in string table table.
OS.AddComment("File index to string table offset subsection");
OS.EmitCVFileChecksumsDirective();
Expand Down Expand Up @@ -457,7 +465,9 @@ void CodeViewDebug::emitDebugInfoForFunction(const Function *GV,
switchToDebugSectionForSymbol(Fn);

StringRef FuncName;
if (auto *SP = GV->getSubprogram())
auto *SP = GV->getSubprogram();
setCurrentSubprogram(SP);
if (SP != nullptr)
FuncName = SP->getDisplayName();

// If our DISubprogram name is empty, use the mangled name.
Expand Down Expand Up @@ -519,6 +529,9 @@ void CodeViewDebug::emitDebugInfoForFunction(const Function *GV,
emitInlinedCallSite(FI, InlinedAt, I->second);
}

if (SP != nullptr)
emitDebugInfoForUDTs(LocalUDTs);

// We're done with this function.
OS.AddComment("Record length");
OS.EmitIntValue(0x0002, 2);
Expand Down Expand Up @@ -755,15 +768,61 @@ TypeIndex CodeViewDebug::lowerType(const DIType *Ty) {
}
}

static const DISubprogram *getQualifiedNameComponents(
const DIScope *Scope, SmallVectorImpl<StringRef> &QualifiedNameComponents) {
const DISubprogram *ClosestSubprogram = nullptr;
while (Scope != nullptr) {
if (ClosestSubprogram == nullptr)
ClosestSubprogram = dyn_cast<DISubprogram>(Scope);
StringRef ScopeName = Scope->getName();
if (!ScopeName.empty())
QualifiedNameComponents.push_back(ScopeName);
Scope = Scope->getScope().resolve();
}
return ClosestSubprogram;
}

static std::string getQualifiedName(ArrayRef<StringRef> QualifiedNameComponents,
StringRef TypeName) {
std::string FullyQualifiedName;
for (StringRef QualifiedNameComponent : reverse(QualifiedNameComponents)) {
FullyQualifiedName.append(QualifiedNameComponent);
FullyQualifiedName.append("::");
}
FullyQualifiedName.append(TypeName);
return FullyQualifiedName;
}

TypeIndex CodeViewDebug::lowerTypeAlias(const DIDerivedType *Ty) {
// TODO: MSVC emits a S_UDT record.
DITypeRef UnderlyingTypeRef = Ty->getBaseType();
TypeIndex UnderlyingTypeIndex = getTypeIndex(UnderlyingTypeRef);
StringRef TypeName = Ty->getName();

SmallVector<StringRef, 5> QualifiedNameComponents;
const DISubprogram *ClosestSubprogram = getQualifiedNameComponents(
Ty->getScope().resolve(), QualifiedNameComponents);

if (ClosestSubprogram == nullptr) {
std::string FullyQualifiedName =
getQualifiedName(QualifiedNameComponents, TypeName);
GlobalUDTs.emplace_back(std::move(FullyQualifiedName), UnderlyingTypeIndex);
} else if (ClosestSubprogram == CurrentSubprogram) {
std::string FullyQualifiedName =
getQualifiedName(QualifiedNameComponents, TypeName);
LocalUDTs.emplace_back(std::move(FullyQualifiedName), UnderlyingTypeIndex);
}
// TODO: What if the ClosestSubprogram is neither null or the current
// subprogram? Currently, the UDT just gets dropped on the floor.
//
// The current behavior is not desirable. To get maximal fidelity, we would
// need to perform all type translation before beginning emission of .debug$S
// and then make LocalUDTs a member of FunctionInfo

if (UnderlyingTypeIndex == TypeIndex(SimpleTypeKind::Int32Long) &&
Ty->getName() == "HRESULT")
TypeName == "HRESULT")
return TypeIndex(SimpleTypeKind::HResult);
if (UnderlyingTypeIndex == TypeIndex(SimpleTypeKind::UInt16Short) &&
Ty->getName() == "wchar_t")
TypeName == "wchar_t")
return TypeIndex(SimpleTypeKind::WideCharacter);
return UnderlyingTypeIndex;
}
Expand Down Expand Up @@ -1307,6 +1366,26 @@ void CodeViewDebug::endCVSubsection(MCSymbol *EndLabel) {
OS.EmitValueToAlignment(4);
}

void CodeViewDebug::emitDebugInfoForUDTs(
ArrayRef<std::pair<std::string, TypeIndex>> UDTs) {
for (const std::pair<std::string, codeview::TypeIndex> &UDT : UDTs) {
MCSymbol *UDTRecordBegin = MMI->getContext().createTempSymbol(),
*UDTRecordEnd = MMI->getContext().createTempSymbol();
OS.AddComment("Record length");
OS.emitAbsoluteSymbolDiff(UDTRecordEnd, UDTRecordBegin, 2);
OS.EmitLabel(UDTRecordBegin);

OS.AddComment("Record kind: S_UDT");
OS.EmitIntValue(unsigned(SymbolKind::S_UDT), 2);

OS.AddComment("Type");
OS.EmitIntValue(UDT.second.getIndex(), 4);

emitNullTerminatedSymbolName(OS, UDT.first);
OS.EmitLabel(UDTRecordEnd);
}
}

void CodeViewDebug::emitDebugInfoForGlobals() {
NamedMDNode *CUs = MMI->getModule()->getNamedMetadata("llvm.dbg.cu");
for (const MDNode *Node : CUs->operands()) {
Expand Down
17 changes: 17 additions & 0 deletions llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.h
View file
Expand Up @@ -144,6 +144,13 @@ class LLVM_LIBRARY_VISIBILITY CodeViewDebug : public DebugHandlerBase {
/// always looked up in the normal TypeIndices map.
DenseMap<const DICompositeType *, codeview::TypeIndex> CompleteTypeIndices;

const DISubprogram *CurrentSubprogram = nullptr;

// The UDTs we have seen while processing types; each entry is a pair of type
// index and type name.
std::vector<std::pair<std::string, codeview::TypeIndex>> LocalUDTs,
GlobalUDTs;

typedef std::map<const DIFile *, std::string> FileToFilepathMapTy;
FileToFilepathMapTy FileToFilepathMap;
StringRef getFullFilepath(const DIFile *S);
Expand All @@ -157,6 +164,13 @@ class LLVM_LIBRARY_VISIBILITY CodeViewDebug : public DebugHandlerBase {
FileIdMap.clear();
FnDebugInfo.clear();
FileToFilepathMap.clear();
LocalUDTs.clear();
GlobalUDTs.clear();
}

void setCurrentSubprogram(const DISubprogram *SP) {
CurrentSubprogram = SP;
LocalUDTs.clear();
}

/// Emit the magic version number at the start of a CodeView type or symbol
Expand All @@ -171,6 +185,9 @@ class LLVM_LIBRARY_VISIBILITY CodeViewDebug : public DebugHandlerBase {

void emitDebugInfoForGlobals();

void emitDebugInfoForUDTs(
ArrayRef<std::pair<std::string, codeview::TypeIndex>> UDTs);

void emitDebugInfoForGlobal(const DIGlobalVariable *DIGV, MCSymbol *GVSym);

/// Opens a subsection of the given kind in a .debug$S codeview section.
Expand Down
8 changes: 8 additions & 0 deletions llvm/test/DebugInfo/COFF/typedef.ll
View file
Expand Up @@ -8,6 +8,14 @@
; CHECK: ]
; CHECK: VarName: foo
; CHECK: }
; CHECK: Subsection [
; CHECK: SubSectionType: Symbols (0xF1)
; CHECK: SubSectionSize: 0xC
; CHECK: UDT {
; CHECK: Type: wchar_t (0x71)
; CHECK: UDTName: XYZ
; CHECK: }
; CHECK: ]

target datalayout = "e-m:x-p:32:32-i64:64-f80:32-n8:16:32-a:0:32-S32"
target triple = "i686-pc-windows-msvc18.0.0"
Expand Down
57 changes: 57 additions & 0 deletions llvm/test/DebugInfo/COFF/udts.ll
View file
@@ -0,0 +1,57 @@
; RUN: llc < %s -filetype=obj | llvm-readobj - -codeview | FileCheck %s
target datalayout = "e-m:x-p:32:32-i64:64-f80:32-n8:16:32-a:0:32-S32"
target triple = "i686-pc-windows-msvc18.0.0"

; C++ source to regenerate:
; $ cat t.cpp
; void f() {
; typedef int FOO;
; FOO f;
; }

; CHECK: ProcStart {
; CHECK: DisplayName: f
; CHECK: LinkageName: ?f@@YAXXZ
; CHECK: }
; CHECK: UDT {
; CHECK-NEXT: Type: int (0x74)
; CHECK-NEXT: UDTName: f::FOO
; CHECK-NEXT: }
; CHECK-NEXT: ProcEnd {
; CHECK-NEXT: }


; Function Attrs: nounwind
define void @"\01?f@@YAXXZ"() #0 !dbg !6 {
entry:
%f = alloca i32, align 4
call void @llvm.dbg.declare(metadata i32* %f, metadata !10, metadata !13), !dbg !14
ret void, !dbg !15
}

; Function Attrs: nounwind readnone
declare void @llvm.dbg.declare(metadata, metadata, metadata) #1

attributes #0 = { nounwind "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="pentium4" "target-features"="+fxsr,+mmx,+sse,+sse2,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }
attributes #1 = { nounwind readnone }

!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!3, !4}
!llvm.ident = !{!5}

!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 3.9.0 (trunk 272079) (llvm/trunk 271895)", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
!1 = !DIFile(filename: "-", directory: "/usr/local/src")
!2 = !{}
!3 = !{i32 2, !"CodeView", i32 1}
!4 = !{i32 2, !"Debug Info Version", i32 3}
!5 = !{!"clang version 3.9.0 (trunk 272079) (llvm/trunk 271895)"}
!6 = distinct !DISubprogram(name: "f", linkageName: "\01?f@@YAXXZ", scope: !7, file: !7, line: 2, type: !8, isLocal: false, isDefinition: true, scopeLine: 2, flags: DIFlagPrototyped, isOptimized: false, unit: !0, variables: !2)
!7 = !DIFile(filename: "<stdin>", directory: "/usr/local/src")
!8 = !DISubroutineType(types: !9)
!9 = !{null}
!10 = !DILocalVariable(name: "f", scope: !6, file: !7, line: 4, type: !11)
!11 = !DIDerivedType(tag: DW_TAG_typedef, name: "FOO", scope: !6, file: !7, line: 3, baseType: !12)
!12 = !DIBasicType(name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
!13 = !DIExpression()
!14 = !DILocation(line: 4, column: 5, scope: !6)
!15 = !DILocation(line: 5, column: 1, scope: !6)

0 comments on commit 3128b10

Please sign in to comment.