diff --git a/llvm/lib/Transforms/Utils/Local.cpp b/llvm/lib/Transforms/Utils/Local.cpp --- a/llvm/lib/Transforms/Utils/Local.cpp +++ b/llvm/lib/Transforms/Utils/Local.cpp @@ -424,23 +424,9 @@ if (I->isEHPad()) return false; - // We don't want debug info removed by anything this general, unless - // debug info is empty. - if (DbgDeclareInst *DDI = dyn_cast(I)) { - if (DDI->getAddress()) - return false; - return true; - } - if (DbgValueInst *DVI = dyn_cast(I)) { - if (DVI->hasArgList() || DVI->getValue(0)) - return false; - return true; - } - if (DbgLabelInst *DLI = dyn_cast(I)) { - if (DLI->getLabel()) - return false; - return true; - } + // We don't want debug info removed by anything this general. + if (isa(I)) + return false; if (auto *CB = dyn_cast(I)) if (isRemovableAlloc(CB, TLI)) diff --git a/llvm/test/DebugInfo/Generic/empty-metadata.ll b/llvm/test/DebugInfo/Generic/empty-metadata.ll new file mode 100644 --- /dev/null +++ b/llvm/test/DebugInfo/Generic/empty-metadata.ll @@ -0,0 +1,37 @@ +; RUN: opt -passes=dce -S %s -o - | FileCheck %s + +;; Check that DCE doesn't remove a dbg intrinsic that has an empty metadata +;; operand. +; CHECK: call void @llvm.dbg.declare(metadata ![[EMPTY:[0-9]+]], +; CHECK: ![[EMPTY]] = !{} + +define dso_local void @fun() local_unnamed_addr #0 !dbg !9 { +entry: + call void @llvm.dbg.declare(metadata !{}, metadata !13, metadata !DIExpression()), !dbg !15 + ret void, !dbg !16 +} + +declare void @llvm.dbg.declare(metadata, metadata, metadata) + +!llvm.dbg.cu = !{!0} +!llvm.module.flags = !{!2, !3, !4, !5, !6, !7} +!llvm.ident = !{!8} + +!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 16.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, splitDebugInlining: false, nameTableKind: None) +!1 = !DIFile(filename: "test.c", directory: "/") +!2 = !{i32 7, !"Dwarf Version", i32 5} +!3 = !{i32 2, !"Debug Info Version", i32 3} +!4 = !{i32 1, !"wchar_size", i32 4} +!5 = !{i32 8, !"PIC Level", i32 2} +!6 = !{i32 7, !"PIE Level", i32 2} +!7 = !{i32 7, !"uwtable", i32 2} +!8 = !{!"clang version 16.0.0"} +!9 = distinct !DISubprogram(name: "fun", scope: !1, file: !1, line: 1, type: !10, scopeLine: 1, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !12) +!10 = !DISubroutineType(types: !11) +!11 = !{null} +!12 = !{!13} +!13 = !DILocalVariable(name: "a", scope: !9, file: !1, line: 1, type: !14) +!14 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed) +!15 = !DILocation(line: 1, column: 18, scope: !9) +!16 = !DILocation(line: 1, column: 21, scope: !9) + diff --git a/llvm/unittests/Transforms/Utils/LocalTest.cpp b/llvm/unittests/Transforms/Utils/LocalTest.cpp --- a/llvm/unittests/Transforms/Utils/LocalTest.cpp +++ b/llvm/unittests/Transforms/Utils/LocalTest.cpp @@ -603,6 +603,47 @@ delete CI; } +TEST(Local, wouldInstructionBeTriviallyDead) { + LLVMContext Ctx; + std::unique_ptr M = parseIR(Ctx, + R"( + define dso_local void @fun() local_unnamed_addr #0 !dbg !9 { + entry: + call void @llvm.dbg.declare(metadata !{}, metadata !13, metadata !DIExpression()), !dbg !16 + ret void, !dbg !16 + } + + declare void @llvm.dbg.declare(metadata, metadata, metadata) + + !llvm.dbg.cu = !{!0} + !llvm.module.flags = !{!2, !3} + !llvm.ident = !{!8} + + !0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 16.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, splitDebugInlining: false, nameTableKind: None) + !1 = !DIFile(filename: "test.c", directory: "/") + !2 = !{i32 7, !"Dwarf Version", i32 5} + !3 = !{i32 2, !"Debug Info Version", i32 3} + !8 = !{!"clang version 16.0.0"} + !9 = distinct !DISubprogram(name: "fun", scope: !1, file: !1, line: 1, type: !10, scopeLine: 1, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !12) + !10 = !DISubroutineType(types: !11) + !11 = !{null} + !12 = !{!13} + !13 = !DILocalVariable(name: "a", scope: !9, file: !1, line: 1, type: !14) + !14 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed) + !16 = !DILocation(line: 1, column: 21, scope: !9) + )"); + bool BrokenDebugInfo = true; + verifyModule(*M, &errs(), &BrokenDebugInfo); + ASSERT_FALSE(BrokenDebugInfo); + + // Get the dbg.declare. + Function &F = *cast(M->getNamedValue("fun")); + Instruction *DbgDeclare = &F.front().front(); + ASSERT_TRUE(isa(DbgDeclare)); + // Debug intrinsics with empty metadata arguments are not dead. + EXPECT_FALSE(wouldInstructionBeTriviallyDead(DbgDeclare)); +} + TEST(Local, ChangeToUnreachable) { LLVMContext Ctx;