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[clang][DebugInfo] Emit global variable definitions for static data members with constant initializers #70639

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58 changes: 47 additions & 11 deletions clang/lib/CodeGen/CGDebugInfo.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -1677,22 +1677,13 @@ CGDebugInfo::CreateRecordStaticField(const VarDecl *Var, llvm::DIType *RecordTy,

unsigned LineNumber = getLineNumber(Var->getLocation());
StringRef VName = Var->getName();
llvm::Constant *C = nullptr;
if (Var->getInit()) {
const APValue *Value = Var->evaluateValue();
if (Value) {
if (Value->isInt())
C = llvm::ConstantInt::get(CGM.getLLVMContext(), Value->getInt());
if (Value->isFloat())
C = llvm::ConstantFP::get(CGM.getLLVMContext(), Value->getFloat());
}
}

llvm::DINode::DIFlags Flags = getAccessFlag(Var->getAccess(), RD);
auto Align = getDeclAlignIfRequired(Var, CGM.getContext());
llvm::DIDerivedType *GV = DBuilder.createStaticMemberType(
RecordTy, VName, VUnit, LineNumber, VTy, Flags, C, Align);
RecordTy, VName, VUnit, LineNumber, VTy, Flags, /* Val */ nullptr, Align);
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This parameter on createStaticMemberType is technically not needed anymore. So could think about removing it in a follow-up

StaticDataMemberCache[Var->getCanonicalDecl()].reset(GV);
StaticDataMemberDefinitionsToEmit.push_back(Var->getCanonicalDecl());
return GV;
}

Expand Down Expand Up @@ -5596,6 +5587,39 @@ void CGDebugInfo::EmitGlobalVariable(const ValueDecl *VD, const APValue &Init) {
TemplateParameters, Align));
}

void CGDebugInfo::EmitGlobalVariable(const VarDecl *VD) {
assert(VD->hasInit());
assert(CGM.getCodeGenOpts().hasReducedDebugInfo());
if (VD->hasAttr<NoDebugAttr>())
return;

auto &GV = DeclCache[VD];
if (GV)
return;

auto const *InitVal = VD->evaluateValue();
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);

GV.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());
Expand Down Expand Up @@ -5866,6 +5890,18 @@ void CGDebugInfo::finalize() {
DBuilder.replaceTemporary(std::move(FwdDecl), cast<llvm::MDNode>(Repl));
}

for (auto const *VD : StaticDataMemberDefinitionsToEmit) {
assert(VD->isStaticDataMember());

if (DeclCache.contains(VD))
continue;

if (!VD->hasInit())
continue;

EmitGlobalVariable(VD);
}

// We keep our own list of retained types, because we need to look
// up the final type in the type cache.
for (auto &RT : RetainedTypes)
Expand Down
6 changes: 6 additions & 0 deletions clang/lib/CodeGen/CGDebugInfo.h
Original file line number Diff line number Diff line change
Expand Up @@ -161,6 +161,9 @@ 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 *>;
Expand Down Expand Up @@ -526,6 +529,9 @@ 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);

Expand Down
13 changes: 9 additions & 4 deletions clang/test/CodeGenCXX/debug-info-class.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -116,11 +116,19 @@ int main(int argc, char **argv) {
// CHECK-SAME: DIFlagFwdDecl
// 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"
Expand Down Expand Up @@ -186,8 +194,5 @@ 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,
94 changes: 94 additions & 0 deletions clang/test/CodeGenCXX/debug-info-static-inline-member.cpp
Original file line number Diff line number Diff line change
@@ -0,0 +1,94 @@
// RUN: %clangxx -target arm64-apple-macosx11.0.0 -g %s -emit-llvm -S -o - | FileCheck --check-prefixes=CHECK %s

enum class Enum : int {
VAL = -1
};

struct Empty {};

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{};
static inline Enum inline_enum = Enum::VAL;

template<typename T>
static constexpr T cexpr_template{};
};

int main() {
Foo f;

// 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>;
}

// 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())
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Why doesn't this have a value/expression? (but INT_VAR2 does)

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Because this one has a corresponding llvm::GlobalVariable which doesn't go down the code-path I added. We emit a DW_AT_location only for this. Should we be emitting both a location and constant in this case?

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Ah, that was the intent (the line 27 taking address-of)? Maybe give the variable a more descriptive name to make it clear this is testing the case where the variable has a definition emitted to the IR

// 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-NOT: extraData:

// CHECK: ![[INT_DECL2:[0-9]+]] = !DIDerivedType(tag: DW_TAG_member, name: "cexpr_int2",
// CHECK-SAME: flags: DIFlagStaticMember
// CHECK-NOT: extraData:

// CHECK: ![[FLOAT_DECL:[0-9]+]] = !DIDerivedType(tag: DW_TAG_member, name: "cexpr_float",
// CHECK-SAME: flags: DIFlagStaticMember
// CHECK-NOT: extraData:

// CHECK: ![[ENUM_DECL:[0-9]+]] = !DIDerivedType(tag: DW_TAG_member, name: "cexpr_enum",
// CHECK-SAME: flags: DIFlagStaticMember
// CHECK-NOT: extraData:

// CHECK: ![[EMPTY_DECL:[0-9]+]] = !DIDerivedType(tag: DW_TAG_member, name: "cexpr_struct_with_addr",
// CHECK-SAME: flags: DIFlagStaticMember
// CHECK-NOT: extraData:

// CHECK: ![[IENUM_DECL:[0-9]+]] = !DIDerivedType(tag: DW_TAG_member, name: "inline_enum",
// CHECK-SAME: flags: DIFlagStaticMember
// CHECK-NOT: extraData:

// CHECK: ![[TEMPLATE_DECL:[0-9]+]] = !DIDerivedType(tag: DW_TAG_member, name: "cexpr_template",
// CHECK-SAME: flags: DIFlagStaticMember
// CHECK-NOT: extraData:

// 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", 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", 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", linkageName:
// CHECK-SAME: isLocal: true, isDefinition: true, declaration: ![[ENUM_DECL]])

// CHECK: !DIGlobalVariableExpression(var: ![[IENUM_VAR:[0-9]+]], expr: !DIExpression(DW_OP_constu, {{.*}}, DW_OP_stack_value))
// CHECK: ![[IENUM_VAR]] = distinct !DIGlobalVariable(name: "inline_enum", linkageName:
// CHECK-SAME: isLocal: true, isDefinition: true, declaration: ![[IENUM_DECL]])

// CHECK: !DIGlobalVariableExpression(var: ![[TEMPLATE_VAR:[0-9]+]], expr: !DIExpression(DW_OP_constu, 0, DW_OP_stack_value))
// CHECK: ![[TEMPLATE_VAR]] = distinct !DIGlobalVariable(name: "cexpr_template", linkageName:
// CHECK-SAME: isLocal: true, isDefinition: true, declaration: ![[TEMPLATE_DECL]], templateParams: ![[TEMPLATE_PARMS:[0-9]+]])
52 changes: 32 additions & 20 deletions clang/test/CodeGenCXX/debug-info-static-member.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -63,32 +63,32 @@ int C::a = 4;
// CHECK-NOT: offset:
// CHECK-SAME: flags: DIFlagStaticMember)
//
// CHECK: !DIDerivedType(tag: DW_TAG_member, name: "const_a"
// CHECK-NOT: size:
// CHECK-NOT: align:
// CHECK-NOT: offset:
// CHECK-SAME: flags: DIFlagStaticMember,
// CHECK-SAME: extraData: i1 true)

// CHECK: !DIDerivedType(tag: DW_TAG_member, name: "const_b"
// CHECK-NOT: size:
// CHECK-NOT: align:
// CHECK-NOT: offset:
// CHECK-SAME: flags: DIFlagProtected | DIFlagStaticMember,
// CHECK-SAME: extraData: float 0x{{.*}})
// CHECK: ![[CONST_A_DECL:[0-9]+]] = !DIDerivedType(tag: DW_TAG_member, name: "const_a"
// CHECK-NOT: size:
// CHECK-NOT: align:
// CHECK-NOT: offset:
// CHECK-SAME: flags: DIFlagStaticMember
// CHECK-NOT: extraData:

// CHECK: ![[CONST_B_DECL:[0-9]+]] = !DIDerivedType(tag: DW_TAG_member, name: "const_b"
// CHECK-NOT: size:
// CHECK-NOT: align:
// CHECK-NOT: offset:
// CHECK-SAME: flags: DIFlagProtected | DIFlagStaticMember
// CHECK-NOT: extraData:

// CHECK: ![[DECL_C:[0-9]+]] = !DIDerivedType(tag: DW_TAG_member, name: "c"
// CHECK-NOT: size:
// CHECK-NOT: align:
// CHECK-NOT: offset:
// CHECK-SAME: flags: DIFlagPublic | DIFlagStaticMember)
//
// CHECK: !DIDerivedType(tag: DW_TAG_member, name: "const_c"
// CHECK-NOT: size:
// CHECK-NOT: align:
// CHECK-NOT: offset:
// CHECK-SAME: flags: DIFlagPublic | DIFlagStaticMember,
// CHECK-SAME: extraData: i32 18)
// CHECK: ![[CONST_C_DECL:[0-9]+]] = !DIDerivedType(tag: DW_TAG_member, name: "const_c"
// CHECK-NOT: size:
// CHECK-NOT: align:
// CHECK-NOT: offset:
// CHECK-SAME: flags: DIFlagPublic | DIFlagStaticMember
// CHECK-NOT: extraData:
//
// CHECK: !DIDerivedType(tag: DW_TAG_member, name: "x_a"
// CHECK-SAME: flags: DIFlagPublic | DIFlagStaticMember)
Expand Down Expand Up @@ -144,7 +144,7 @@ struct V {
// const_va is not emitted for MS targets.
// NOT-MS: !DIDerivedType(tag: DW_TAG_member, name: "const_va",
// NOT-MS-SAME: line: [[@LINE-5]]
// NOT-MS-SAME: extraData: i32 42
// NOT-MS-NOT: extraData:
const int V::const_va;

namespace x {
Expand All @@ -156,3 +156,15 @@ 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]])

// CHECK: !DIGlobalVariableExpression(var: ![[CONST_B_VAR:[0-9]+]], expr: !DIExpression(DW_OP_constu, {{.*}}, DW_OP_stack_value))
// CHECK: ![[CONST_B_VAR]] = distinct !DIGlobalVariable(name: "const_b"
// CHECK-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]])
Original file line number Diff line number Diff line change
Expand Up @@ -102,9 +102,10 @@ def test(self):
# it does not crash.
self.expect("image lookup -t A")

# dsymutil strips the debug info for classes that only have const static
# data members without a definition namespace scope.
@expectedFailureAll(debug_info=["dsym"])
# For debug-info produced by older versions of clang, dsymutil strips the
# debug info for classes that only have const static data members without
# definitions.
@expectedFailureAll(compiler=["clang"], compiler_version=["<", "18.0"])
def test_class_with_only_const_static(self):
self.build()
lldbutil.run_to_source_breakpoint(
Expand Down
9 changes: 5 additions & 4 deletions lldb/test/API/tools/lldb-dap/variables/TestDAP_variables.py
Original file line number Diff line number Diff line change
Expand Up @@ -87,10 +87,11 @@ def verify_values(self, verify_dict, actual, varref_dict=None, expression=None):
def verify_variables(self, verify_dict, variables, varref_dict=None):
for variable in variables:
name = variable["name"]
self.assertIn(
name, verify_dict, 'variable "%s" in verify dictionary' % (name)
)
self.verify_values(verify_dict[name], variable, varref_dict)
if not name.startswith("std::"):
self.assertIn(
name, verify_dict, 'variable "%s" in verify dictionary' % (name)
)
self.verify_values(verify_dict[name], variable, varref_dict)

def darwin_dwarf_missing_obj(self, initCommands):
self.build(debug_info="dwarf")
Expand Down