[clang][DebugInfo] Revert "emit definitions for constant-initialized static data-members" #74580
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…tialized static data-members" This commit reverts the changes in llvm#71780 and all of its follow-up patches. We got reports of the `.debug_names/.debug_gnu_pubnames/gdb_index/etc.` sections growing by a non-trivial amount for some large projects. While GCC does index definitions for static data member constants, they do so *only* for explicitly `constexpr` members. We were indexing *all* constant-initialized const-static members, which is likely where the significant size difference comes from. However, only emitting explicitly `constexpr` variables into the index doesn't seem like a good way forward, since from clang's perspective `const`-static integrals are `constexpr` too, and that shouldn't be any different in the debug-info component. Also, as new code moves to `constexpr` instead of `const` static for constants, such solution would just delay the growth of the Names index. To prevent the size regression we revert to not emitting definitions for static data-members that have no location. To support access to such constants from LLDB we'll most likely have to have to make LLDB find the constants by looking at the containing class first.
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@llvm/pr-subscribers-lldb @llvm/pr-subscribers-clang Author: Michael Buch (Michael137) ChangesThis commit reverts the changes in #71780 and all of its follow-up patches. We got reports of the To prevent the size regression we revert to not emitting definitions for static data-members that have no location. To support access to such constants from LLDB we'll most likely have to have to make LLDB find the constants by looking at the containing class first. Full diff: https://github.com/llvm/llvm-project/pull/74580.diff 7 Files Affected:
diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp
index 602e325e560f9..7cf661994a29c 100644
--- a/clang/lib/CodeGen/CGDebugInfo.cpp
+++ b/clang/lib/CodeGen/CGDebugInfo.cpp
@@ -69,29 +69,6 @@ static uint32_t getDeclAlignIfRequired(const Decl *D, const ASTContext &Ctx) {
return D->hasAttr<AlignedAttr>() ? D->getMaxAlignment() : 0;
}
-/// Given a VarDecl corresponding to either the definition or
-/// declaration of a C++ static data member, if it has a constant
-/// initializer and is evaluatable, return the evaluated value.
-/// Returns std::nullopt otherwise.
-static std::optional<APValue>
-evaluateConstantInitializer(const clang::VarDecl *VD,
- const clang::ASTContext &Ctx) {
- assert(VD != nullptr);
-
- if (!VD->isStaticDataMember())
- return std::nullopt;
-
- if (!VD->isUsableInConstantExpressions(Ctx))
- return std::nullopt;
-
- auto const *InitExpr = VD->getAnyInitializer();
- Expr::EvalResult Result;
- if (!InitExpr->EvaluateAsConstantExpr(Result, Ctx))
- return std::nullopt;
-
- return Result.Val;
-}
-
CGDebugInfo::CGDebugInfo(CodeGenModule &CGM)
: CGM(CGM), DebugKind(CGM.getCodeGenOpts().getDebugInfo()),
DebugTypeExtRefs(CGM.getCodeGenOpts().DebugTypeExtRefs),
@@ -1724,7 +1701,6 @@ CGDebugInfo::CreateRecordStaticField(const VarDecl *Var, llvm::DIType *RecordTy,
llvm::DIDerivedType *GV = DBuilder.createStaticMemberType(
RecordTy, VName, VUnit, LineNumber, VTy, Flags, C, Tag, Align);
StaticDataMemberCache[Var->getCanonicalDecl()].reset(GV);
- StaticDataMemberDefinitionsToEmit.push_back(Var->getCanonicalDecl());
return GV;
}
@@ -5628,41 +5604,6 @@ void CGDebugInfo::EmitGlobalVariable(const ValueDecl *VD, const APValue &Init) {
TemplateParameters, Align));
}
-void CGDebugInfo::EmitGlobalVariable(const VarDecl *VD) {
- assert(CGM.getCodeGenOpts().hasReducedDebugInfo());
- if (VD->hasAttr<NoDebugAttr>())
- return;
-
- const auto CacheIt = DeclCache.find(VD);
- if (CacheIt != DeclCache.end())
- return;
-
- const auto InitVal = evaluateConstantInitializer(VD, CGM.getContext());
- if (!InitVal)
- return;
-
- llvm::DIFile *Unit = nullptr;
- llvm::DIScope *DContext = nullptr;
- unsigned LineNo;
- StringRef DeclName, LinkageName;
- QualType T;
- llvm::MDTuple *TemplateParameters = nullptr;
- collectVarDeclProps(VD, Unit, LineNo, T, DeclName, LinkageName,
- TemplateParameters, DContext);
-
- auto Align = getDeclAlignIfRequired(VD, CGM.getContext());
- llvm::DINodeArray Annotations = CollectBTFDeclTagAnnotations(VD);
- llvm::DIExpression *InitExpr = createConstantValueExpression(VD, *InitVal);
-
- // Omit linkage name for variable definitions that represent constants.
- // There hasn't been a need from consumers yet to have it attached.
- DeclCache[VD].reset(DBuilder.createGlobalVariableExpression(
- TheCU, DeclName, /* LinkageName */ {}, Unit, LineNo,
- getOrCreateType(T, Unit), true, true, InitExpr,
- getOrCreateStaticDataMemberDeclarationOrNull(VD), TemplateParameters,
- Align, Annotations));
-}
-
void CGDebugInfo::EmitExternalVariable(llvm::GlobalVariable *Var,
const VarDecl *D) {
assert(CGM.getCodeGenOpts().hasReducedDebugInfo());
@@ -5867,20 +5808,6 @@ void CGDebugInfo::setDwoId(uint64_t Signature) {
}
void CGDebugInfo::finalize() {
- // We can't use a for-each here because `EmitGlobalVariable`
- // may push new decls into `StaticDataMemberDefinitionsToEmit`,
- // which would invalidate any iterator.
- for (size_t i = 0; i < StaticDataMemberDefinitionsToEmit.size(); ++i) {
- auto const *VD = StaticDataMemberDefinitionsToEmit[i];
-
- assert(VD && VD->isStaticDataMember());
-
- if (DeclCache.contains(VD))
- continue;
-
- EmitGlobalVariable(VD);
- }
-
// Creating types might create further types - invalidating the current
// element and the size(), so don't cache/reference them.
for (size_t i = 0; i != ObjCInterfaceCache.size(); ++i) {
diff --git a/clang/lib/CodeGen/CGDebugInfo.h b/clang/lib/CodeGen/CGDebugInfo.h
index 3e4c133b7f2b9..7b60e94555d06 100644
--- a/clang/lib/CodeGen/CGDebugInfo.h
+++ b/clang/lib/CodeGen/CGDebugInfo.h
@@ -161,9 +161,6 @@ class CGDebugInfo {
llvm::DenseMap<const Decl *, llvm::TypedTrackingMDRef<llvm::DIDerivedType>>
StaticDataMemberCache;
- /// Keeps track of static data members for which we should emit a definition.
- std::vector<const VarDecl *> StaticDataMemberDefinitionsToEmit;
-
using ParamDecl2StmtTy = llvm::DenseMap<const ParmVarDecl *, const Stmt *>;
using Param2DILocTy =
llvm::DenseMap<const ParmVarDecl *, llvm::DILocalVariable *>;
@@ -529,9 +526,6 @@ class CGDebugInfo {
/// Emit a constant global variable's debug info.
void EmitGlobalVariable(const ValueDecl *VD, const APValue &Init);
- /// Emit debug-info for a variable with a constant initializer.
- void EmitGlobalVariable(const VarDecl *VD);
-
/// Emit information about an external variable.
void EmitExternalVariable(llvm::GlobalVariable *GV, const VarDecl *Decl);
diff --git a/clang/test/CodeGenCXX/debug-info-class.cpp b/clang/test/CodeGenCXX/debug-info-class.cpp
index a3111cd7c3640..8d610ca68a9d4 100644
--- a/clang/test/CodeGenCXX/debug-info-class.cpp
+++ b/clang/test/CodeGenCXX/debug-info-class.cpp
@@ -117,18 +117,11 @@ int main(int argc, char **argv) {
// CHECK-NOT: identifier:
// CHECK-SAME: ){{$}}
-// CHECK: !DIGlobalVariableExpression(var: ![[HDR_VAR:[0-9]+]], expr: !DIExpression(DW_OP_constu, 52, DW_OP_stack_value))
-// CHECK: ![[HDR_VAR]] = distinct !DIGlobalVariable(name: "HdrSize",
-// CHECK-SAME: isLocal: true, isDefinition: true, declaration: ![[HDR_VAR_DECL:[0-9]+]])
-// CHECK: ![[INT:[0-9]+]] = !DIBasicType(name: "int"
-// CHECK: ![[HDR_VAR_DECL]] = !DIDerivedType(tag: DW_TAG_member, name: "HdrSize"
-
-// CHECK: !DICompositeType(tag: DW_TAG_structure_type, name: "A"
-
// CHECK: !DICompositeType(tag: DW_TAG_structure_type, name: "I"
// CHECK-NOT: DIFlagFwdDecl
// CHECK-SAME: ){{$}}
+// CHECK: ![[INT:[0-9]+]] = !DIBasicType(name: "int"
// CHECK: !DICompositeType(tag: DW_TAG_structure_type, name: "foo"
// CHECK: !DICompositeType(tag: DW_TAG_class_type, name: "bar"
// CHECK: !DICompositeType(tag: DW_TAG_union_type, name: "baz"
@@ -194,5 +187,8 @@ int main(int argc, char **argv) {
// CHECK: [[G_INNER_I]] = !DIDerivedType(tag: DW_TAG_member, name: "j"
// CHECK-SAME: baseType: ![[INT]]
+// CHECK: !DICompositeType(tag: DW_TAG_structure_type, name: "A"
+// CHECK: !DIDerivedType(tag: DW_TAG_member, name: "HdrSize"
+
// CHECK: ![[EXCEPTLOC]] = !DILocation(line: 100,
// CHECK: ![[RETLOC]] = !DILocation(line: 99,
diff --git a/clang/test/CodeGenCXX/debug-info-static-inline-member.cpp b/clang/test/CodeGenCXX/debug-info-static-inline-member.cpp
deleted file mode 100644
index 3230b0e0c9c60..0000000000000
--- a/clang/test/CodeGenCXX/debug-info-static-inline-member.cpp
+++ /dev/null
@@ -1,104 +0,0 @@
-// RUN: %clangxx -target arm64-apple-macosx11.0.0 -g -gdwarf-4 -debug-info-kind=standalone %s -emit-llvm -S -o - | FileCheck --check-prefixes=CHECK %s
-// RUN: %clangxx -target arm64-apple-macosx11.0.0 -g -gdwarf-4 -debug-info-kind=limited %s -emit-llvm -S -o - | FileCheck --check-prefixes=CHECK %s
-
-enum class Enum : int {
- VAL = -1
-};
-
-struct Empty {};
-struct Fwd;
-
-constexpr auto func() { return 25; }
-
-struct Foo {
- static constexpr int cexpr_int_with_addr = func();
- static constexpr int cexpr_int2 = func() + 1;
- static constexpr float cexpr_float = 2.0 + 1.0;
- static constexpr Enum cexpr_enum = Enum::VAL;
- static constexpr Empty cexpr_struct_with_addr{};
-
- template<typename T, unsigned V>
- static constexpr auto cexpr_template = V;
-
- static const auto empty_templated = cexpr_template<Fwd, 1>;
-};
-
-int main() {
- Foo f;
- //Bar b;
-
- // Force global variable definitions to be emitted.
- (void)&Foo::cexpr_int_with_addr;
- (void)&Foo::cexpr_struct_with_addr;
-
- return Foo::cexpr_int_with_addr + Foo::cexpr_float
- + (int)Foo::cexpr_enum + Foo::cexpr_template<short, 5>
- + Foo::empty_templated;
-}
-
-// CHECK: @{{.*}}cexpr_int_with_addr{{.*}} =
-// CHECK-SAME: !dbg ![[INT_GLOBAL:[0-9]+]]
-
-// CHECK: @{{.*}}cexpr_struct_with_addr{{.*}} =
-// CHECK-SAME !dbg ![[EMPTY_GLOBAL:[0-9]+]]
-
-// CHECK: !DIGlobalVariableExpression(var: ![[INT_VAR:[0-9]+]], expr: !DIExpression())
-// CHECK: ![[INT_VAR]] = distinct !DIGlobalVariable(name: "cexpr_int_with_addr", linkageName:
-// CHECK-SAME: isLocal: false, isDefinition: true, declaration: ![[INT_DECL:[0-9]+]])
-
-// CHECK: ![[INT_DECL]] = !DIDerivedType(tag: DW_TAG_member, name: "cexpr_int_with_addr",
-// CHECK-SAME: flags: DIFlagStaticMember
-// CHECK-SAME: extraData: i32 25
-
-// CHECK: ![[INT_DECL2:[0-9]+]] = !DIDerivedType(tag: DW_TAG_member, name: "cexpr_int2",
-// CHECK-SAME: flags: DIFlagStaticMember
-// CHECK-SAME: extraData: i32 26
-
-// CHECK: ![[FLOAT_DECL:[0-9]+]] = !DIDerivedType(tag: DW_TAG_member, name: "cexpr_float",
-// CHECK-SAME: flags: DIFlagStaticMember
-// CHECK-SAME: extraData: float
-
-// CHECK: ![[ENUM_DECL:[0-9]+]] = !DIDerivedType(tag: DW_TAG_member, name: "cexpr_enum",
-// CHECK-SAME: flags: DIFlagStaticMember
-// CHECK-SAME: extraData: i32 -1
-
-// CHECK: ![[EMPTY_DECL:[0-9]+]] = !DIDerivedType(tag: DW_TAG_member, name: "cexpr_struct_with_addr",
-// CHECK-SAME: flags: DIFlagStaticMember
-// CHECK-NOT: extraData:
-
-// CHECK: ![[EMPTY_TEMPLATED_DECL:[0-9]+]] = !DIDerivedType(tag: DW_TAG_member, name: "empty_templated",
-// CHECK-SAME: flags: DIFlagStaticMember
-// CHECK-SAME: extraData: i32 1
-
-// CHECK: ![[TEMPLATE_DECL:[0-9]+]] = !DIDerivedType(tag: DW_TAG_member, name: "cexpr_template",
-// CHECK-SAME: flags: DIFlagStaticMember
-// CHECK-SAME: extraData: i32 1
-
-// CHECK: !DIGlobalVariableExpression(var: ![[EMPTY_VAR:[0-9]+]], expr: !DIExpression())
-// CHECK: ![[EMPTY_VAR]] = distinct !DIGlobalVariable(name: "cexpr_struct_with_addr", linkageName:
-// CHECK-SAME: isLocal: false, isDefinition: true, declaration: ![[EMPTY_DECL]])
-
-// CHECK: !DIGlobalVariableExpression(var: ![[INT_VAR2:[0-9]+]], expr: !DIExpression(DW_OP_constu, 26, DW_OP_stack_value))
-// CHECK: ![[INT_VAR2]] = distinct !DIGlobalVariable(name: "cexpr_int2"
-// CHECK-NOT: linkageName:
-// CHECK-SAME: isLocal: true, isDefinition: true, declaration: ![[INT_DECL2]])
-
-// CHECK: !DIGlobalVariableExpression(var: ![[FLOAT_VAR:[0-9]+]], expr: !DIExpression(DW_OP_constu, {{.*}}, DW_OP_stack_value))
-// CHECK: ![[FLOAT_VAR]] = distinct !DIGlobalVariable(name: "cexpr_float"
-// CHECK-NOT: linkageName:
-// CHECK-SAME: isLocal: true, isDefinition: true, declaration: ![[FLOAT_DECL]])
-
-// CHECK: !DIGlobalVariableExpression(var: ![[ENUM_VAR:[0-9]+]], expr: !DIExpression(DW_OP_constu, {{.*}}, DW_OP_stack_value))
-// CHECK: ![[ENUM_VAR]] = distinct !DIGlobalVariable(name: "cexpr_enum"
-// CHECK-NOT: linkageName:
-// CHECK-SAME: isLocal: true, isDefinition: true, declaration: ![[ENUM_DECL]])
-
-// CHECK: !DIGlobalVariableExpression(var: ![[EMPTY_TEMPLATED_VAR:[0-9]+]], expr: !DIExpression(DW_OP_constu, 1, DW_OP_stack_value))
-// CHECK: ![[EMPTY_TEMPLATED_VAR]] = distinct !DIGlobalVariable(name: "empty_templated"
-// CHECK-NOT: linkageName:
-// CHECK-SAME: isLocal: true, isDefinition: true, declaration: ![[EMPTY_TEMPLATED_DECL]])
-
-// CHECK: !DIGlobalVariableExpression(var: ![[TEMPLATE_VAR:[0-9]+]], expr: !DIExpression(DW_OP_constu, 5, DW_OP_stack_value))
-// CHECK: ![[TEMPLATE_VAR]] = distinct !DIGlobalVariable(name: "cexpr_template"
-// CHECK-NOT: linkageName:
-// CHECK-SAME: isLocal: true, isDefinition: true, declaration: ![[TEMPLATE_DECL]], templateParams: ![[TEMPLATE_PARMS_2:[0-9]+]])
diff --git a/clang/test/CodeGenCXX/debug-info-static-member.cpp b/clang/test/CodeGenCXX/debug-info-static-member.cpp
index a111dc84b6e66..972ca62d7b267 100644
--- a/clang/test/CodeGenCXX/debug-info-static-member.cpp
+++ b/clang/test/CodeGenCXX/debug-info-static-member.cpp
@@ -1,8 +1,8 @@
-// RUN: %clangxx -target x86_64-unknown-unknown -g -gdwarf-4 %s -emit-llvm -S -o - | FileCheck --check-prefixes=CHECK,DWARF4,CPP11,NOT-MS %s
+// RUN: %clangxx -target x86_64-unknown-unknown -g -gdwarf-4 %s -emit-llvm -S -o - | FileCheck --check-prefixes=CHECK,DWARF4,NOT-MS %s
// RUN: %clangxx -target x86_64-unknown-unknown -g -gdwarf-4 -std=c++98 %s -emit-llvm -S -o - | FileCheck --check-prefixes=CHECK,DWARF4,NOT-MS %s
-// RUN: %clangxx -target x86_64-unknown-unknown -g -gdwarf-4 -std=c++11 %s -emit-llvm -S -o - | FileCheck --check-prefixes=CHECK,DWARF4,CPP11,NOT-MS %s
-// RUN: %clangxx -target x86_64-unknown-unknown -g -gdwarf-5 -std=c++11 %s -emit-llvm -S -o - | FileCheck --check-prefixes=CHECK,DWARF5,CPP11 %s
-// RUN: %clangxx -target x86_64-windows-msvc -g -gdwarf-4 %s -emit-llvm -S -o - | FileCheck --check-prefixes=CHECK,DWARF4,CPP11 %s
+// RUN: %clangxx -target x86_64-unknown-unknown -g -gdwarf-4 -std=c++11 %s -emit-llvm -S -o - | FileCheck --check-prefixes=CHECK,DWARF4,NOT-MS %s
+// RUN: %clangxx -target x86_64-unknown-unknown -g -gdwarf-5 -std=c++11 %s -emit-llvm -S -o - | FileCheck --check-prefixes=CHECK,DWARF5 %s
+// RUN: %clangxx -target x86_64-windows-msvc -g -gdwarf-4 %s -emit-llvm -S -o - | FileCheck --check-prefixes=CHECK,DWARF4 %s
// PR14471
// CHECK: @{{.*}}a{{.*}} = dso_local global i32 4, align 4, !dbg [[A:![0-9]+]]
@@ -166,15 +166,3 @@ struct y {
};
int y::z;
}
-
-// CHECK: !DIGlobalVariableExpression(var: ![[CONST_A_VAR:[0-9]+]], expr: !DIExpression(DW_OP_constu, 1, DW_OP_stack_value))
-// CHECK: ![[CONST_A_VAR]] = distinct !DIGlobalVariable(name: "const_a"
-// CHECK-SAME: isLocal: true, isDefinition: true, declaration: ![[CONST_A_DECL]])
-
-// CPP11: !DIGlobalVariableExpression(var: ![[CONST_B_VAR:[0-9]+]], expr: !DIExpression(DW_OP_constu, {{.*}}, DW_OP_stack_value))
-// CPP11: ![[CONST_B_VAR]] = distinct !DIGlobalVariable(name: "const_b"
-// CPP11-SAME: isLocal: true, isDefinition: true, declaration: ![[CONST_B_DECL]])
-
-// CHECK: !DIGlobalVariableExpression(var: ![[CONST_C_VAR:[0-9]+]], expr: !DIExpression(DW_OP_constu, 18, DW_OP_stack_value))
-// CHECK: ![[CONST_C_VAR]] = distinct !DIGlobalVariable(name: "const_c"
-// CHECK-SAME: isLocal: true, isDefinition: true, declaration: ![[CONST_C_DECL]])
diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp b/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
index c3b22f889c2f4..e3c64640c7917 100644
--- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
+++ b/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
@@ -142,54 +142,6 @@ static bool ShouldIgnoreArtificialField(llvm::StringRef FieldName) {
|| FieldName.starts_with("_vptr.");
}
-std::optional<DWARFFormValue>
-DWARFASTParserClang::FindConstantOnVariableDefinition(DWARFDIE die) {
- assert(die.Tag() == DW_TAG_member || die.Tag() == DW_TAG_variable);
-
- auto *dwarf = die.GetDWARF();
- if (!dwarf)
- return {};
-
- ConstString name{die.GetName()};
- if (!name)
- return {};
-
- auto *CU = die.GetCU();
- if (!CU)
- return {};
-
- DWARFASTParser *dwarf_ast = dwarf->GetDWARFParser(*CU);
- auto parent_decl_ctx = dwarf_ast->GetDeclContextContainingUIDFromDWARF(die);
-
- // Make sure we populate the GetDieToVariable cache.
- VariableList variables;
- dwarf->FindGlobalVariables(name, parent_decl_ctx, UINT_MAX, variables);
-
- // The cache contains the variable definition whose DW_AT_specification
- // points to our declaration DIE. Look up that definition using our
- // declaration.
- auto const &die_to_var = dwarf->GetDIEToVariable();
- auto it = die_to_var.find(die.GetDIE());
- if (it == die_to_var.end())
- return {};
-
- auto var_sp = it->getSecond();
- assert(var_sp != nullptr);
-
- if (!var_sp->GetLocationIsConstantValueData())
- return {};
-
- auto def = dwarf->GetDIE(var_sp->GetID());
- auto def_attrs = def.GetAttributes();
- DWARFFormValue form_value;
- if (!def_attrs.ExtractFormValueAtIndex(
- def_attrs.FindAttributeIndex(llvm::dwarf::DW_AT_const_value),
- form_value))
- return {};
-
- return form_value;
-}
-
TypeSP DWARFASTParserClang::ParseTypeFromClangModule(const SymbolContext &sc,
const DWARFDIE &die,
Log *log) {
@@ -2916,23 +2868,11 @@ void DWARFASTParserClang::CreateStaticMemberVariable(
bool unused;
// TODO: Support float/double static members as well.
- if (!ct.IsIntegerOrEnumerationType(unused))
+ if (!ct.IsIntegerOrEnumerationType(unused) || !attrs.const_value_form)
return;
- auto maybe_const_form_value = attrs.const_value_form;
-
- // Newer versions of Clang don't emit the DW_AT_const_value
- // on the declaration of an inline static data member. Instead
- // it's attached to the definition DIE. If that's the case,
- // try and fetch it.
- if (!maybe_const_form_value) {
- maybe_const_form_value = FindConstantOnVariableDefinition(die);
- if (!maybe_const_form_value)
- return;
- }
-
llvm::Expected<llvm::APInt> const_value_or_err =
- ExtractIntFromFormValue(ct, *maybe_const_form_value);
+ ExtractIntFromFormValue(ct, *attrs.const_value_form);
if (!const_value_or_err) {
LLDB_LOG_ERROR(log, const_value_or_err.takeError(),
"Failed to add const value to variable {1}: {0}",
diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.h b/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.h
index 7b495419cf324..3e28e54d6220d 100644
--- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.h
+++ b/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.h
@@ -413,17 +413,6 @@ class DWARFASTParserClang : public lldb_private::plugin::dwarf::DWARFASTParser {
lldb_private::CompilerType &class_clang_type,
const lldb::AccessType default_accesibility,
lldb_private::ClangASTImporter::LayoutInfo &layout_info);
-
- /// Tries to find the definition DW_TAG_variable DIE of the the specified
- /// DW_TAG_member 'die'. If such definition exists, returns the
- /// DW_AT_const_value of that definition if available. Returns std::nullopt
- /// otherwise.
- ///
- /// In newer versions of clang, DW_AT_const_value attributes are not attached
- /// to the declaration of a inline static data-member anymore, but rather on
- /// its definition. This function is used to locate said constant.
- std::optional<lldb_private::plugin::dwarf::DWARFFormValue>
- FindConstantOnVariableDefinition(lldb_private::plugin::dwarf::DWARFDIE die);
};
/// Parsed form of all attributes that are relevant for type reconstruction.
|
|
@llvm/pr-subscribers-debuginfo Author: Michael Buch (Michael137) ChangesThis commit reverts the changes in #71780 and all of its follow-up patches. We got reports of the To prevent the size regression we revert to not emitting definitions for static data-members that have no location. To support access to such constants from LLDB we'll most likely have to have to make LLDB find the constants by looking at the containing class first. Full diff: https://github.com/llvm/llvm-project/pull/74580.diff 7 Files Affected:
diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp
index 602e325e560f9..7cf661994a29c 100644
--- a/clang/lib/CodeGen/CGDebugInfo.cpp
+++ b/clang/lib/CodeGen/CGDebugInfo.cpp
@@ -69,29 +69,6 @@ static uint32_t getDeclAlignIfRequired(const Decl *D, const ASTContext &Ctx) {
return D->hasAttr<AlignedAttr>() ? D->getMaxAlignment() : 0;
}
-/// Given a VarDecl corresponding to either the definition or
-/// declaration of a C++ static data member, if it has a constant
-/// initializer and is evaluatable, return the evaluated value.
-/// Returns std::nullopt otherwise.
-static std::optional<APValue>
-evaluateConstantInitializer(const clang::VarDecl *VD,
- const clang::ASTContext &Ctx) {
- assert(VD != nullptr);
-
- if (!VD->isStaticDataMember())
- return std::nullopt;
-
- if (!VD->isUsableInConstantExpressions(Ctx))
- return std::nullopt;
-
- auto const *InitExpr = VD->getAnyInitializer();
- Expr::EvalResult Result;
- if (!InitExpr->EvaluateAsConstantExpr(Result, Ctx))
- return std::nullopt;
-
- return Result.Val;
-}
-
CGDebugInfo::CGDebugInfo(CodeGenModule &CGM)
: CGM(CGM), DebugKind(CGM.getCodeGenOpts().getDebugInfo()),
DebugTypeExtRefs(CGM.getCodeGenOpts().DebugTypeExtRefs),
@@ -1724,7 +1701,6 @@ CGDebugInfo::CreateRecordStaticField(const VarDecl *Var, llvm::DIType *RecordTy,
llvm::DIDerivedType *GV = DBuilder.createStaticMemberType(
RecordTy, VName, VUnit, LineNumber, VTy, Flags, C, Tag, Align);
StaticDataMemberCache[Var->getCanonicalDecl()].reset(GV);
- StaticDataMemberDefinitionsToEmit.push_back(Var->getCanonicalDecl());
return GV;
}
@@ -5628,41 +5604,6 @@ void CGDebugInfo::EmitGlobalVariable(const ValueDecl *VD, const APValue &Init) {
TemplateParameters, Align));
}
-void CGDebugInfo::EmitGlobalVariable(const VarDecl *VD) {
- assert(CGM.getCodeGenOpts().hasReducedDebugInfo());
- if (VD->hasAttr<NoDebugAttr>())
- return;
-
- const auto CacheIt = DeclCache.find(VD);
- if (CacheIt != DeclCache.end())
- return;
-
- const auto InitVal = evaluateConstantInitializer(VD, CGM.getContext());
- if (!InitVal)
- return;
-
- llvm::DIFile *Unit = nullptr;
- llvm::DIScope *DContext = nullptr;
- unsigned LineNo;
- StringRef DeclName, LinkageName;
- QualType T;
- llvm::MDTuple *TemplateParameters = nullptr;
- collectVarDeclProps(VD, Unit, LineNo, T, DeclName, LinkageName,
- TemplateParameters, DContext);
-
- auto Align = getDeclAlignIfRequired(VD, CGM.getContext());
- llvm::DINodeArray Annotations = CollectBTFDeclTagAnnotations(VD);
- llvm::DIExpression *InitExpr = createConstantValueExpression(VD, *InitVal);
-
- // Omit linkage name for variable definitions that represent constants.
- // There hasn't been a need from consumers yet to have it attached.
- DeclCache[VD].reset(DBuilder.createGlobalVariableExpression(
- TheCU, DeclName, /* LinkageName */ {}, Unit, LineNo,
- getOrCreateType(T, Unit), true, true, InitExpr,
- getOrCreateStaticDataMemberDeclarationOrNull(VD), TemplateParameters,
- Align, Annotations));
-}
-
void CGDebugInfo::EmitExternalVariable(llvm::GlobalVariable *Var,
const VarDecl *D) {
assert(CGM.getCodeGenOpts().hasReducedDebugInfo());
@@ -5867,20 +5808,6 @@ void CGDebugInfo::setDwoId(uint64_t Signature) {
}
void CGDebugInfo::finalize() {
- // We can't use a for-each here because `EmitGlobalVariable`
- // may push new decls into `StaticDataMemberDefinitionsToEmit`,
- // which would invalidate any iterator.
- for (size_t i = 0; i < StaticDataMemberDefinitionsToEmit.size(); ++i) {
- auto const *VD = StaticDataMemberDefinitionsToEmit[i];
-
- assert(VD && VD->isStaticDataMember());
-
- if (DeclCache.contains(VD))
- continue;
-
- EmitGlobalVariable(VD);
- }
-
// Creating types might create further types - invalidating the current
// element and the size(), so don't cache/reference them.
for (size_t i = 0; i != ObjCInterfaceCache.size(); ++i) {
diff --git a/clang/lib/CodeGen/CGDebugInfo.h b/clang/lib/CodeGen/CGDebugInfo.h
index 3e4c133b7f2b9..7b60e94555d06 100644
--- a/clang/lib/CodeGen/CGDebugInfo.h
+++ b/clang/lib/CodeGen/CGDebugInfo.h
@@ -161,9 +161,6 @@ class CGDebugInfo {
llvm::DenseMap<const Decl *, llvm::TypedTrackingMDRef<llvm::DIDerivedType>>
StaticDataMemberCache;
- /// Keeps track of static data members for which we should emit a definition.
- std::vector<const VarDecl *> StaticDataMemberDefinitionsToEmit;
-
using ParamDecl2StmtTy = llvm::DenseMap<const ParmVarDecl *, const Stmt *>;
using Param2DILocTy =
llvm::DenseMap<const ParmVarDecl *, llvm::DILocalVariable *>;
@@ -529,9 +526,6 @@ class CGDebugInfo {
/// Emit a constant global variable's debug info.
void EmitGlobalVariable(const ValueDecl *VD, const APValue &Init);
- /// Emit debug-info for a variable with a constant initializer.
- void EmitGlobalVariable(const VarDecl *VD);
-
/// Emit information about an external variable.
void EmitExternalVariable(llvm::GlobalVariable *GV, const VarDecl *Decl);
diff --git a/clang/test/CodeGenCXX/debug-info-class.cpp b/clang/test/CodeGenCXX/debug-info-class.cpp
index a3111cd7c3640..8d610ca68a9d4 100644
--- a/clang/test/CodeGenCXX/debug-info-class.cpp
+++ b/clang/test/CodeGenCXX/debug-info-class.cpp
@@ -117,18 +117,11 @@ int main(int argc, char **argv) {
// CHECK-NOT: identifier:
// CHECK-SAME: ){{$}}
-// CHECK: !DIGlobalVariableExpression(var: ![[HDR_VAR:[0-9]+]], expr: !DIExpression(DW_OP_constu, 52, DW_OP_stack_value))
-// CHECK: ![[HDR_VAR]] = distinct !DIGlobalVariable(name: "HdrSize",
-// CHECK-SAME: isLocal: true, isDefinition: true, declaration: ![[HDR_VAR_DECL:[0-9]+]])
-// CHECK: ![[INT:[0-9]+]] = !DIBasicType(name: "int"
-// CHECK: ![[HDR_VAR_DECL]] = !DIDerivedType(tag: DW_TAG_member, name: "HdrSize"
-
-// CHECK: !DICompositeType(tag: DW_TAG_structure_type, name: "A"
-
// CHECK: !DICompositeType(tag: DW_TAG_structure_type, name: "I"
// CHECK-NOT: DIFlagFwdDecl
// CHECK-SAME: ){{$}}
+// CHECK: ![[INT:[0-9]+]] = !DIBasicType(name: "int"
// CHECK: !DICompositeType(tag: DW_TAG_structure_type, name: "foo"
// CHECK: !DICompositeType(tag: DW_TAG_class_type, name: "bar"
// CHECK: !DICompositeType(tag: DW_TAG_union_type, name: "baz"
@@ -194,5 +187,8 @@ int main(int argc, char **argv) {
// CHECK: [[G_INNER_I]] = !DIDerivedType(tag: DW_TAG_member, name: "j"
// CHECK-SAME: baseType: ![[INT]]
+// CHECK: !DICompositeType(tag: DW_TAG_structure_type, name: "A"
+// CHECK: !DIDerivedType(tag: DW_TAG_member, name: "HdrSize"
+
// CHECK: ![[EXCEPTLOC]] = !DILocation(line: 100,
// CHECK: ![[RETLOC]] = !DILocation(line: 99,
diff --git a/clang/test/CodeGenCXX/debug-info-static-inline-member.cpp b/clang/test/CodeGenCXX/debug-info-static-inline-member.cpp
deleted file mode 100644
index 3230b0e0c9c60..0000000000000
--- a/clang/test/CodeGenCXX/debug-info-static-inline-member.cpp
+++ /dev/null
@@ -1,104 +0,0 @@
-// RUN: %clangxx -target arm64-apple-macosx11.0.0 -g -gdwarf-4 -debug-info-kind=standalone %s -emit-llvm -S -o - | FileCheck --check-prefixes=CHECK %s
-// RUN: %clangxx -target arm64-apple-macosx11.0.0 -g -gdwarf-4 -debug-info-kind=limited %s -emit-llvm -S -o - | FileCheck --check-prefixes=CHECK %s
-
-enum class Enum : int {
- VAL = -1
-};
-
-struct Empty {};
-struct Fwd;
-
-constexpr auto func() { return 25; }
-
-struct Foo {
- static constexpr int cexpr_int_with_addr = func();
- static constexpr int cexpr_int2 = func() + 1;
- static constexpr float cexpr_float = 2.0 + 1.0;
- static constexpr Enum cexpr_enum = Enum::VAL;
- static constexpr Empty cexpr_struct_with_addr{};
-
- template<typename T, unsigned V>
- static constexpr auto cexpr_template = V;
-
- static const auto empty_templated = cexpr_template<Fwd, 1>;
-};
-
-int main() {
- Foo f;
- //Bar b;
-
- // Force global variable definitions to be emitted.
- (void)&Foo::cexpr_int_with_addr;
- (void)&Foo::cexpr_struct_with_addr;
-
- return Foo::cexpr_int_with_addr + Foo::cexpr_float
- + (int)Foo::cexpr_enum + Foo::cexpr_template<short, 5>
- + Foo::empty_templated;
-}
-
-// CHECK: @{{.*}}cexpr_int_with_addr{{.*}} =
-// CHECK-SAME: !dbg ![[INT_GLOBAL:[0-9]+]]
-
-// CHECK: @{{.*}}cexpr_struct_with_addr{{.*}} =
-// CHECK-SAME !dbg ![[EMPTY_GLOBAL:[0-9]+]]
-
-// CHECK: !DIGlobalVariableExpression(var: ![[INT_VAR:[0-9]+]], expr: !DIExpression())
-// CHECK: ![[INT_VAR]] = distinct !DIGlobalVariable(name: "cexpr_int_with_addr", linkageName:
-// CHECK-SAME: isLocal: false, isDefinition: true, declaration: ![[INT_DECL:[0-9]+]])
-
-// CHECK: ![[INT_DECL]] = !DIDerivedType(tag: DW_TAG_member, name: "cexpr_int_with_addr",
-// CHECK-SAME: flags: DIFlagStaticMember
-// CHECK-SAME: extraData: i32 25
-
-// CHECK: ![[INT_DECL2:[0-9]+]] = !DIDerivedType(tag: DW_TAG_member, name: "cexpr_int2",
-// CHECK-SAME: flags: DIFlagStaticMember
-// CHECK-SAME: extraData: i32 26
-
-// CHECK: ![[FLOAT_DECL:[0-9]+]] = !DIDerivedType(tag: DW_TAG_member, name: "cexpr_float",
-// CHECK-SAME: flags: DIFlagStaticMember
-// CHECK-SAME: extraData: float
-
-// CHECK: ![[ENUM_DECL:[0-9]+]] = !DIDerivedType(tag: DW_TAG_member, name: "cexpr_enum",
-// CHECK-SAME: flags: DIFlagStaticMember
-// CHECK-SAME: extraData: i32 -1
-
-// CHECK: ![[EMPTY_DECL:[0-9]+]] = !DIDerivedType(tag: DW_TAG_member, name: "cexpr_struct_with_addr",
-// CHECK-SAME: flags: DIFlagStaticMember
-// CHECK-NOT: extraData:
-
-// CHECK: ![[EMPTY_TEMPLATED_DECL:[0-9]+]] = !DIDerivedType(tag: DW_TAG_member, name: "empty_templated",
-// CHECK-SAME: flags: DIFlagStaticMember
-// CHECK-SAME: extraData: i32 1
-
-// CHECK: ![[TEMPLATE_DECL:[0-9]+]] = !DIDerivedType(tag: DW_TAG_member, name: "cexpr_template",
-// CHECK-SAME: flags: DIFlagStaticMember
-// CHECK-SAME: extraData: i32 1
-
-// CHECK: !DIGlobalVariableExpression(var: ![[EMPTY_VAR:[0-9]+]], expr: !DIExpression())
-// CHECK: ![[EMPTY_VAR]] = distinct !DIGlobalVariable(name: "cexpr_struct_with_addr", linkageName:
-// CHECK-SAME: isLocal: false, isDefinition: true, declaration: ![[EMPTY_DECL]])
-
-// CHECK: !DIGlobalVariableExpression(var: ![[INT_VAR2:[0-9]+]], expr: !DIExpression(DW_OP_constu, 26, DW_OP_stack_value))
-// CHECK: ![[INT_VAR2]] = distinct !DIGlobalVariable(name: "cexpr_int2"
-// CHECK-NOT: linkageName:
-// CHECK-SAME: isLocal: true, isDefinition: true, declaration: ![[INT_DECL2]])
-
-// CHECK: !DIGlobalVariableExpression(var: ![[FLOAT_VAR:[0-9]+]], expr: !DIExpression(DW_OP_constu, {{.*}}, DW_OP_stack_value))
-// CHECK: ![[FLOAT_VAR]] = distinct !DIGlobalVariable(name: "cexpr_float"
-// CHECK-NOT: linkageName:
-// CHECK-SAME: isLocal: true, isDefinition: true, declaration: ![[FLOAT_DECL]])
-
-// CHECK: !DIGlobalVariableExpression(var: ![[ENUM_VAR:[0-9]+]], expr: !DIExpression(DW_OP_constu, {{.*}}, DW_OP_stack_value))
-// CHECK: ![[ENUM_VAR]] = distinct !DIGlobalVariable(name: "cexpr_enum"
-// CHECK-NOT: linkageName:
-// CHECK-SAME: isLocal: true, isDefinition: true, declaration: ![[ENUM_DECL]])
-
-// CHECK: !DIGlobalVariableExpression(var: ![[EMPTY_TEMPLATED_VAR:[0-9]+]], expr: !DIExpression(DW_OP_constu, 1, DW_OP_stack_value))
-// CHECK: ![[EMPTY_TEMPLATED_VAR]] = distinct !DIGlobalVariable(name: "empty_templated"
-// CHECK-NOT: linkageName:
-// CHECK-SAME: isLocal: true, isDefinition: true, declaration: ![[EMPTY_TEMPLATED_DECL]])
-
-// CHECK: !DIGlobalVariableExpression(var: ![[TEMPLATE_VAR:[0-9]+]], expr: !DIExpression(DW_OP_constu, 5, DW_OP_stack_value))
-// CHECK: ![[TEMPLATE_VAR]] = distinct !DIGlobalVariable(name: "cexpr_template"
-// CHECK-NOT: linkageName:
-// CHECK-SAME: isLocal: true, isDefinition: true, declaration: ![[TEMPLATE_DECL]], templateParams: ![[TEMPLATE_PARMS_2:[0-9]+]])
diff --git a/clang/test/CodeGenCXX/debug-info-static-member.cpp b/clang/test/CodeGenCXX/debug-info-static-member.cpp
index a111dc84b6e66..972ca62d7b267 100644
--- a/clang/test/CodeGenCXX/debug-info-static-member.cpp
+++ b/clang/test/CodeGenCXX/debug-info-static-member.cpp
@@ -1,8 +1,8 @@
-// RUN: %clangxx -target x86_64-unknown-unknown -g -gdwarf-4 %s -emit-llvm -S -o - | FileCheck --check-prefixes=CHECK,DWARF4,CPP11,NOT-MS %s
+// RUN: %clangxx -target x86_64-unknown-unknown -g -gdwarf-4 %s -emit-llvm -S -o - | FileCheck --check-prefixes=CHECK,DWARF4,NOT-MS %s
// RUN: %clangxx -target x86_64-unknown-unknown -g -gdwarf-4 -std=c++98 %s -emit-llvm -S -o - | FileCheck --check-prefixes=CHECK,DWARF4,NOT-MS %s
-// RUN: %clangxx -target x86_64-unknown-unknown -g -gdwarf-4 -std=c++11 %s -emit-llvm -S -o - | FileCheck --check-prefixes=CHECK,DWARF4,CPP11,NOT-MS %s
-// RUN: %clangxx -target x86_64-unknown-unknown -g -gdwarf-5 -std=c++11 %s -emit-llvm -S -o - | FileCheck --check-prefixes=CHECK,DWARF5,CPP11 %s
-// RUN: %clangxx -target x86_64-windows-msvc -g -gdwarf-4 %s -emit-llvm -S -o - | FileCheck --check-prefixes=CHECK,DWARF4,CPP11 %s
+// RUN: %clangxx -target x86_64-unknown-unknown -g -gdwarf-4 -std=c++11 %s -emit-llvm -S -o - | FileCheck --check-prefixes=CHECK,DWARF4,NOT-MS %s
+// RUN: %clangxx -target x86_64-unknown-unknown -g -gdwarf-5 -std=c++11 %s -emit-llvm -S -o - | FileCheck --check-prefixes=CHECK,DWARF5 %s
+// RUN: %clangxx -target x86_64-windows-msvc -g -gdwarf-4 %s -emit-llvm -S -o - | FileCheck --check-prefixes=CHECK,DWARF4 %s
// PR14471
// CHECK: @{{.*}}a{{.*}} = dso_local global i32 4, align 4, !dbg [[A:![0-9]+]]
@@ -166,15 +166,3 @@ struct y {
};
int y::z;
}
-
-// CHECK: !DIGlobalVariableExpression(var: ![[CONST_A_VAR:[0-9]+]], expr: !DIExpression(DW_OP_constu, 1, DW_OP_stack_value))
-// CHECK: ![[CONST_A_VAR]] = distinct !DIGlobalVariable(name: "const_a"
-// CHECK-SAME: isLocal: true, isDefinition: true, declaration: ![[CONST_A_DECL]])
-
-// CPP11: !DIGlobalVariableExpression(var: ![[CONST_B_VAR:[0-9]+]], expr: !DIExpression(DW_OP_constu, {{.*}}, DW_OP_stack_value))
-// CPP11: ![[CONST_B_VAR]] = distinct !DIGlobalVariable(name: "const_b"
-// CPP11-SAME: isLocal: true, isDefinition: true, declaration: ![[CONST_B_DECL]])
-
-// CHECK: !DIGlobalVariableExpression(var: ![[CONST_C_VAR:[0-9]+]], expr: !DIExpression(DW_OP_constu, 18, DW_OP_stack_value))
-// CHECK: ![[CONST_C_VAR]] = distinct !DIGlobalVariable(name: "const_c"
-// CHECK-SAME: isLocal: true, isDefinition: true, declaration: ![[CONST_C_DECL]])
diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp b/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
index c3b22f889c2f4..e3c64640c7917 100644
--- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
+++ b/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
@@ -142,54 +142,6 @@ static bool ShouldIgnoreArtificialField(llvm::StringRef FieldName) {
|| FieldName.starts_with("_vptr.");
}
-std::optional<DWARFFormValue>
-DWARFASTParserClang::FindConstantOnVariableDefinition(DWARFDIE die) {
- assert(die.Tag() == DW_TAG_member || die.Tag() == DW_TAG_variable);
-
- auto *dwarf = die.GetDWARF();
- if (!dwarf)
- return {};
-
- ConstString name{die.GetName()};
- if (!name)
- return {};
-
- auto *CU = die.GetCU();
- if (!CU)
- return {};
-
- DWARFASTParser *dwarf_ast = dwarf->GetDWARFParser(*CU);
- auto parent_decl_ctx = dwarf_ast->GetDeclContextContainingUIDFromDWARF(die);
-
- // Make sure we populate the GetDieToVariable cache.
- VariableList variables;
- dwarf->FindGlobalVariables(name, parent_decl_ctx, UINT_MAX, variables);
-
- // The cache contains the variable definition whose DW_AT_specification
- // points to our declaration DIE. Look up that definition using our
- // declaration.
- auto const &die_to_var = dwarf->GetDIEToVariable();
- auto it = die_to_var.find(die.GetDIE());
- if (it == die_to_var.end())
- return {};
-
- auto var_sp = it->getSecond();
- assert(var_sp != nullptr);
-
- if (!var_sp->GetLocationIsConstantValueData())
- return {};
-
- auto def = dwarf->GetDIE(var_sp->GetID());
- auto def_attrs = def.GetAttributes();
- DWARFFormValue form_value;
- if (!def_attrs.ExtractFormValueAtIndex(
- def_attrs.FindAttributeIndex(llvm::dwarf::DW_AT_const_value),
- form_value))
- return {};
-
- return form_value;
-}
-
TypeSP DWARFASTParserClang::ParseTypeFromClangModule(const SymbolContext &sc,
const DWARFDIE &die,
Log *log) {
@@ -2916,23 +2868,11 @@ void DWARFASTParserClang::CreateStaticMemberVariable(
bool unused;
// TODO: Support float/double static members as well.
- if (!ct.IsIntegerOrEnumerationType(unused))
+ if (!ct.IsIntegerOrEnumerationType(unused) || !attrs.const_value_form)
return;
- auto maybe_const_form_value = attrs.const_value_form;
-
- // Newer versions of Clang don't emit the DW_AT_const_value
- // on the declaration of an inline static data member. Instead
- // it's attached to the definition DIE. If that's the case,
- // try and fetch it.
- if (!maybe_const_form_value) {
- maybe_const_form_value = FindConstantOnVariableDefinition(die);
- if (!maybe_const_form_value)
- return;
- }
-
llvm::Expected<llvm::APInt> const_value_or_err =
- ExtractIntFromFormValue(ct, *maybe_const_form_value);
+ ExtractIntFromFormValue(ct, *attrs.const_value_form);
if (!const_value_or_err) {
LLDB_LOG_ERROR(log, const_value_or_err.takeError(),
"Failed to add const value to variable {1}: {0}",
diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.h b/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.h
index 7b495419cf324..3e28e54d6220d 100644
--- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.h
+++ b/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.h
@@ -413,17 +413,6 @@ class DWARFASTParserClang : public lldb_private::plugin::dwarf::DWARFASTParser {
lldb_private::CompilerType &class_clang_type,
const lldb::AccessType default_accesibility,
lldb_private::ClangASTImporter::LayoutInfo &layout_info);
-
- /// Tries to find the definition DW_TAG_variable DIE of the the specified
- /// DW_TAG_member 'die'. If such definition exists, returns the
- /// DW_AT_const_value of that definition if available. Returns std::nullopt
- /// otherwise.
- ///
- /// In newer versions of clang, DW_AT_const_value attributes are not attached
- /// to the declaration of a inline static data-member anymore, but rather on
- /// its definition. This function is used to locate said constant.
- std::optional<lldb_private::plugin::dwarf::DWARFFormValue>
- FindConstantOnVariableDefinition(lldb_private::plugin::dwarf::DWARFDIE die);
};
/// Parsed form of all attributes that are relevant for type reconstruction.
|
cor3ntin
approved these changes
Dec 6, 2023
|
See #74070 |
Was going to wait until some more people had the chance to look. But if urgent, I don't think there should be any trouble merging this sooner |
Tangentially related to: https://discourse.llvm.org/t/rfc-improve-dwarf-5-debug-names-type-lookup-parsing-speed/74151/31?u=dblaikie Clang/LLVM do know the difference between type-invariant members and type variant ones (type invariant members are in the |
|
Could we please land this now? |
I'll merge the PR for now to unblock and address this later |
felipepiovezan
added a commit
that referenced
this pull request
Dec 6, 2023
These tests started passing after this PR landed: #74580
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This commit reverts the changes in #71780 and all of its follow-up patches.
We got reports of the
.debug_names/.debug_gnu_pubnames/gdb_index/etc.sections growing by a non-trivial amount for some large projects. While GCC emits definitions for static data member constants into the Names index, they do so only for explicitlyconstexprmembers. We were indexing all constant-initialized const-static members, which is likely where the significant size difference comes from. However, only emitting explicitlyconstexprvariables into the index doesn't seem like a good way forward, since from clang's perspectiveconst-static integrals areconstexprtoo, and that shouldn't be any different in the debug-info component. Also, as new code moves toconstexprinstead ofconststatic for constants, such solution would just delay the growth of the Names index.To prevent the size regression we revert to not emitting definitions for static data-members that have no location.
To support access to such constants from LLDB we'll most likely have to have to make LLDB find the constants by looking at the containing class first.