[clang] e403f4f - [clang][DebugInfo] Allow function-local statics and types to be scoped within a lexical block
Kristina Bessonova via cfe-commits
cfe-commits at lists.llvm.org
Mon Dec 6 02:20:40 PST 2021
Author: Kristina Bessonova
Date: 2021-12-06T12:19:09+02:00
New Revision: e403f4fdc88322201040f2bee7b328e8a78e2f7f
URL: https://github.com/llvm/llvm-project/commit/e403f4fdc88322201040f2bee7b328e8a78e2f7f
DIFF: https://github.com/llvm/llvm-project/commit/e403f4fdc88322201040f2bee7b328e8a78e2f7f.diff
LOG: [clang][DebugInfo] Allow function-local statics and types to be scoped within a lexical block
This is almost a reincarnation of https://reviews.llvm.org/D15977 originally
implemented by Amjad Aboud. It was discussed on llvm-dev [0], committed
with its backend counterpart [1], but finally reverted [2].
This patch makes clang to emit debug info for function-local static variables,
records (classes, structs and unions) and typdefs correctly scoped if
those function-local entites defined within a lexical (bracketed) block.
Before this patch, clang emits all those entities directly scoped in
DISubprogram no matter where they were really defined, causing
debug info loss (reported several times in [3], [4], [5]).
[0] https://lists.llvm.org/pipermail/llvm-dev/2015-November/092551.html
[1] https://reviews.llvm.org/rG30e7a8f694a19553f64b3a3a5de81ce317b9ec2f
[2] https://reviews.llvm.org/rGdc4531e552af6c880a69d226d3666756198fbdc8
[3] https://bugs.llvm.org/show_bug.cgi?id=19238
[4] https://bugs.llvm.org/show_bug.cgi?id=23164
[5] https://bugs.llvm.org/show_bug.cgi?id=44695
Reviewed By: dblaikie
Differential Revision: https://reviews.llvm.org/D113743
Added:
clang/test/CodeGenCXX/debug-info-lexcial-block.cpp
Modified:
clang/lib/CodeGen/CGDebugInfo.cpp
clang/lib/CodeGen/CGDebugInfo.h
clang/lib/CodeGen/CGDecl.cpp
Removed:
################################################################################
diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp
index af651e6f44b7c..75eec22e4e4e5 100644
--- a/clang/lib/CodeGen/CGDebugInfo.cpp
+++ b/clang/lib/CodeGen/CGDebugInfo.cpp
@@ -227,6 +227,20 @@ llvm::DIScope *CGDebugInfo::getContextDescriptor(const Decl *Context,
return Default;
}
+void CGDebugInfo::recordDeclarationLexicalScope(const Decl &D) {
+ assert(LexicalBlockMap.find(&D) == LexicalBlockMap.end() &&
+ "D is already mapped to a lexical block scope");
+ if (!LexicalBlockStack.empty())
+ LexicalBlockMap.insert({&D, LexicalBlockStack.back()});
+}
+
+llvm::DIScope *CGDebugInfo::getDeclarationLexicalScope(const Decl *D) {
+ auto I = LexicalBlockMap.find(D);
+ if (I != LexicalBlockMap.end())
+ return I->second;
+ return getDeclContextDescriptor(cast<Decl>(D));
+}
+
PrintingPolicy CGDebugInfo::getPrintingPolicy() const {
PrintingPolicy PP = CGM.getContext().getPrintingPolicy();
@@ -1346,13 +1360,13 @@ llvm::DIType *CGDebugInfo::CreateType(const TypedefType *Ty,
// declared.
SourceLocation Loc = Ty->getDecl()->getLocation();
+ llvm::DIScope *TDContext = getDeclarationLexicalScope(Ty->getDecl());
uint32_t Align = getDeclAlignIfRequired(Ty->getDecl(), CGM.getContext());
// Typedefs are derived from some other type.
llvm::DINodeArray Annotations = CollectBTFDeclTagAnnotations(Ty->getDecl());
return DBuilder.createTypedef(Underlying, Ty->getDecl()->getName(),
getOrCreateFile(Loc), getLineNumber(Loc),
- getDeclContextDescriptor(Ty->getDecl()), Align,
- Annotations);
+ TDContext, Align, Annotations);
}
static unsigned getDwarfCC(CallingConv CC) {
@@ -3251,7 +3265,7 @@ llvm::DIType *CGDebugInfo::CreateEnumType(const EnumType *Ty) {
// entered into the ReplaceMap: finalize() will replace the first
// FwdDecl with the second and then replace the second with
// complete type.
- llvm::DIScope *EDContext = getDeclContextDescriptor(ED);
+ llvm::DIScope *EDContext = getDeclarationLexicalScope(ED);
llvm::DIFile *DefUnit = getOrCreateFile(ED->getLocation());
llvm::TempDIScope TmpContext(DBuilder.createReplaceableCompositeType(
llvm::dwarf::DW_TAG_enumeration_type, "", TheCU, DefUnit, 0));
@@ -3294,7 +3308,7 @@ llvm::DIType *CGDebugInfo::CreateTypeDefinition(const EnumType *Ty) {
llvm::DIFile *DefUnit = getOrCreateFile(ED->getLocation());
unsigned Line = getLineNumber(ED->getLocation());
- llvm::DIScope *EnumContext = getDeclContextDescriptor(ED);
+ llvm::DIScope *EnumContext = getDeclarationLexicalScope(ED);
llvm::DIType *ClassTy = getOrCreateType(ED->getIntegerType(), DefUnit);
return DBuilder.createEnumerationType(EnumContext, ED->getName(), DefUnit,
Line, Size, Align, EltArray, ClassTy,
@@ -3597,7 +3611,7 @@ llvm::DICompositeType *CGDebugInfo::CreateLimitedType(const RecordType *Ty) {
Line = getLineNumber(Loc);
}
- llvm::DIScope *RDContext = getDeclContextDescriptor(RD);
+ llvm::DIScope *RDContext = getDeclarationLexicalScope(RD);
// If we ended up creating the type during the context chain construction,
// just return that.
@@ -3790,6 +3804,14 @@ void CGDebugInfo::collectVarDeclProps(const VarDecl *VD, llvm::DIFile *&Unit,
TemplateParameters = nullptr;
}
+ // Get context for static locals (that are technically globals) the same way
+ // we do for "local" locals -- by using current lexical block.
+ if (VD->isStaticLocal()) {
+ assert(!LexicalBlockStack.empty() && "Region stack mismatch, stack empty!");
+ VDContext = LexicalBlockStack.back();
+ return;
+ }
+
// Since we emit declarations (DW_AT_members) for static members, place the
// definition of those static members in the namespace they were declared in
// in the source code (the lexical decl context).
diff --git a/clang/lib/CodeGen/CGDebugInfo.h b/clang/lib/CodeGen/CGDebugInfo.h
index a7b72fa5f5a65..1350ee6808cc2 100644
--- a/clang/lib/CodeGen/CGDebugInfo.h
+++ b/clang/lib/CodeGen/CGDebugInfo.h
@@ -139,6 +139,11 @@ class CGDebugInfo {
/// Keep track of our current nested lexical block.
std::vector<llvm::TypedTrackingMDRef<llvm::DIScope>> LexicalBlockStack;
+
+ /// Map of AST declaration to its lexical block scope.
+ llvm::DenseMap<const Decl *, llvm::TypedTrackingMDRef<llvm::DIScope>>
+ LexicalBlockMap;
+
llvm::DenseMap<const Decl *, llvm::TrackingMDRef> RegionMap;
/// Keep track of LexicalBlockStack counter at the beginning of a
/// function. This is used to pop unbalanced regions at the end of a
@@ -543,6 +548,12 @@ class CGDebugInfo {
/// Emit an Objective-C interface type standalone debug info.
llvm::DIType *getOrCreateInterfaceType(QualType Ty, SourceLocation Loc);
+ /// Map AST declaration to its lexical block scope if available.
+ void recordDeclarationLexicalScope(const Decl &D);
+
+ /// Get lexical scope of AST declaration.
+ llvm::DIScope *getDeclarationLexicalScope(const Decl *D);
+
/// Emit standalone debug info for a type.
llvm::DIType *getOrCreateStandaloneType(QualType Ty, SourceLocation Loc);
diff --git a/clang/lib/CodeGen/CGDecl.cpp b/clang/lib/CodeGen/CGDecl.cpp
index 941671c614824..742bc8eb3dbdb 100644
--- a/clang/lib/CodeGen/CGDecl.cpp
+++ b/clang/lib/CodeGen/CGDecl.cpp
@@ -103,17 +103,21 @@ void CodeGenFunction::EmitDecl(const Decl &D) {
llvm_unreachable("Declaration should not be in declstmts!");
case Decl::Record: // struct/union/class X;
case Decl::CXXRecord: // struct/union/class X; [C++]
- if (CGDebugInfo *DI = getDebugInfo())
+ if (CGDebugInfo *DI = getDebugInfo()) {
+ DI->recordDeclarationLexicalScope(D);
if (cast<RecordDecl>(D).getDefinition())
DI->EmitAndRetainType(getContext().getRecordType(cast<RecordDecl>(&D)));
+ }
return;
case Decl::Enum: // enum X;
- if (CGDebugInfo *DI = getDebugInfo())
+ if (CGDebugInfo *DI = getDebugInfo()) {
+ DI->recordDeclarationLexicalScope(D);
if (cast<EnumDecl>(D).getDefinition())
DI->EmitAndRetainType(getContext().getEnumType(cast<EnumDecl>(&D)));
+ }
return;
- case Decl::Function: // void X();
case Decl::EnumConstant: // enum ? { X = ? }
+ case Decl::Function: // void X();
case Decl::StaticAssert: // static_assert(X, ""); [C++0x]
case Decl::Label: // __label__ x;
case Decl::Import:
@@ -132,11 +136,11 @@ void CodeGenFunction::EmitDecl(const Decl &D) {
case Decl::NamespaceAlias:
if (CGDebugInfo *DI = getDebugInfo())
- DI->EmitNamespaceAlias(cast<NamespaceAliasDecl>(D));
+ DI->EmitNamespaceAlias(cast<NamespaceAliasDecl>(D));
return;
case Decl::Using: // using X; [C++]
if (CGDebugInfo *DI = getDebugInfo())
- DI->EmitUsingDecl(cast<UsingDecl>(D));
+ DI->EmitUsingDecl(cast<UsingDecl>(D));
return;
case Decl::UsingEnum: // using enum X; [C++]
if (CGDebugInfo *DI = getDebugInfo())
@@ -172,8 +176,10 @@ void CodeGenFunction::EmitDecl(const Decl &D) {
case Decl::Typedef: // typedef int X;
case Decl::TypeAlias: { // using X = int; [C++0x]
QualType Ty = cast<TypedefNameDecl>(D).getUnderlyingType();
- if (CGDebugInfo *DI = getDebugInfo())
+ if (CGDebugInfo *DI = getDebugInfo()) {
+ DI->recordDeclarationLexicalScope(D);
DI->EmitAndRetainType(Ty);
+ }
if (Ty->isVariablyModifiedType())
EmitVariablyModifiedType(Ty);
return;
diff --git a/clang/test/CodeGenCXX/debug-info-lexcial-block.cpp b/clang/test/CodeGenCXX/debug-info-lexcial-block.cpp
new file mode 100644
index 0000000000000..75b4b2c052bd3
--- /dev/null
+++ b/clang/test/CodeGenCXX/debug-info-lexcial-block.cpp
@@ -0,0 +1,27 @@
+// RUN: %clang_cc1 -triple x86_64-none-linux-gnu -emit-llvm -debug-info-kind=limited %s -o - | FileCheck %s
+
+void foo() {
+ static int bar = 1;
+ {
+ struct X {};
+ typedef char Y;
+ static int bar = 0;
+ // The following basic block is intended, in order to check the case where
+ // types "X", "Y" are defined in a
diff erent scope than where they are used.
+ // They should have the scope they are defined at as their parent scope.
+ {
+ X a;
+ Y b;
+ }
+ }
+}
+
+// CHECK: !{{[0-9]+}} = distinct !DIGlobalVariable(name: "bar", scope: [[FSCOPE:![0-9]+]]
+// CHECK: [[FSCOPE]] = distinct !DISubprogram(name: "foo"
+// CHECK: !{{[0-9]+}} = distinct !DIGlobalVariable(name: "bar", scope: [[LBSCOPE:![0-9]+]]
+// CHECK: [[LBSCOPE]] = distinct !DILexicalBlock(scope: [[FSCOPE]]
+// CHECK: !{{[0-9]+}} = !DILocalVariable(name: "a", scope: [[LBSCOPE2:![0-9]+]], {{.*}} type: [[STRUCT:![0-9]+]]
+// CHECK: [[LBSCOPE2]] = distinct !DILexicalBlock(scope: [[LBSCOPE]]
+// CHECK: [[STRUCT]] = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "X", scope: [[LBSCOPE]]
+// CHECK: !{{[0-9]+}} = !DILocalVariable(name: "b", scope: [[LBSCOPE2]], {{.*}} type: [[TYPEDEF:![0-9]+]]
+// CHECK: [[TYPEDEF]] = !DIDerivedType(tag: DW_TAG_typedef, name: "Y", scope: [[LBSCOPE]]
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