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Merged
merged 1 commit into from
Jun 27, 2025
Merged

Prevent a crash when a global variable has debug metadata #145918

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6 changes: 3 additions & 3 deletions llvm/lib/IR/DebugInfo.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -50,7 +50,7 @@ TinyPtrVector<DbgDeclareInst *> llvm::findDbgDeclares(Value *V) {
// DenseMap lookup. This check is a bitfield datamember lookup.
if (!V->isUsedByMetadata())
return {};
auto *L = LocalAsMetadata::getIfExists(V);
auto *L = ValueAsMetadata::getIfExists(V);
if (!L)
return {};
auto *MDV = MetadataAsValue::getIfExists(V->getContext(), L);
Expand All @@ -69,7 +69,7 @@ TinyPtrVector<DbgVariableRecord *> llvm::findDVRDeclares(Value *V) {
// DenseMap lookup. This check is a bitfield datamember lookup.
if (!V->isUsedByMetadata())
return {};
auto *L = LocalAsMetadata::getIfExists(V);
auto *L = ValueAsMetadata::getIfExists(V);
if (!L)
return {};

Expand All @@ -86,7 +86,7 @@ TinyPtrVector<DbgVariableRecord *> llvm::findDVRValues(Value *V) {
// DenseMap lookup. This check is a bitfield datamember lookup.
if (!V->isUsedByMetadata())
return {};
auto *L = LocalAsMetadata::getIfExists(V);
auto *L = ValueAsMetadata::getIfExists(V);
if (!L)
return {};

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43 changes: 43 additions & 0 deletions llvm/unittests/IR/DebugInfoTest.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -195,6 +195,49 @@ TEST(MetadataTest, DeleteInstUsedByDbgRecord) {
EXPECT_TRUE(isa<UndefValue>(DVRs[0]->getValue(0)));
}

TEST(MetadataTest, GlobalConstantMetadataUsedByDbgRecord) {
LLVMContext C;
std::unique_ptr<Module> M = parseIR(C, R"(
@x = dso_local global i32 0, align 4
declare void @llvm.dbg.value(metadata, metadata, metadata) #0

define i16 @f(i16 %a) !dbg !6 {
%b = add i16 %a, 1, !dbg !11
call void @llvm.dbg.declare(metadata ptr @x, metadata !9, metadata !DIExpression()), !dbg !11
call void @llvm.dbg.value(metadata ptr @x, metadata !9, metadata !DIExpression()), !dbg !11
ret i16 0, !dbg !11
}

attributes #0 = { nounwind readnone speculatable willreturn }

!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!5}

!0 = distinct !DICompileUnit(language: DW_LANG_C, file: !1, producer: "debugify", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
!1 = !DIFile(filename: "t.ll", directory: "/")
!2 = !{}
!5 = !{i32 2, !"Debug Info Version", i32 3}
!6 = distinct !DISubprogram(name: "foo", linkageName: "foo", scope: null, file: !1, line: 1, type: !7, scopeLine: 1, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !8)
!7 = !DISubroutineType(types: !2)
!8 = !{!9}
!9 = !DILocalVariable(name: "1", scope: !6, file: !1, line: 1, type: !10)
!10 = !DIBasicType(name: "ty16", size: 16, encoding: DW_ATE_unsigned)
!11 = !DILocation(line: 1, column: 1, scope: !6)
)");

// Find the global @x
Value *V = M->getNamedValue("x");

// Find the dbg.value
auto DVIs = findDbgDeclares(V);
auto DVRs = findDVRDeclares(V);
auto DVRVs = findDVRValues(V);

EXPECT_EQ(DVRs[0]->getNumVariableLocationOps(), 1u);
EXPECT_TRUE(DVRVs.size() == 1);
EXPECT_FALSE(isa<UndefValue>(DVRs[0]->getValue(0)));
}

TEST(DbgVariableIntrinsic, EmptyMDIsKillLocation) {
LLVMContext Ctx;
std::unique_ptr<Module> M = parseIR(Ctx, R"(
Expand Down