diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfFile.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfFile.cpp index eab798c0da784..cd1279d202132 100644 --- a/llvm/lib/CodeGen/AsmPrinter/DwarfFile.cpp +++ b/llvm/lib/CodeGen/AsmPrinter/DwarfFile.cpp @@ -121,7 +121,19 @@ void DwarfFile::addScopeLabel(LexicalScope *LS, DbgLabel *Label) { std::pair DwarfFile::addRange(const DwarfCompileUnit &CU, SmallVector R) { - CURangeLists.push_back( - RangeSpanList{Asm->createTempSymbol("debug_ranges"), &CU, std::move(R)}); + bool CanReuseLastRange = false; + + if (!CURangeLists.empty()) { + auto Last = CURangeLists.back(); + if (Last.CU == &CU && Last.Ranges == R) { + CanReuseLastRange = true; + } + } + + if (!CanReuseLastRange) { + CURangeLists.push_back(RangeSpanList{Asm->createTempSymbol("debug_ranges"), + &CU, std::move(R)}); + } + return std::make_pair(CURangeLists.size() - 1, &CURangeLists.back()); } diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfFile.h b/llvm/lib/CodeGen/AsmPrinter/DwarfFile.h index f76858fc2f36a..0fc2b91ddfa91 100644 --- a/llvm/lib/CodeGen/AsmPrinter/DwarfFile.h +++ b/llvm/lib/CodeGen/AsmPrinter/DwarfFile.h @@ -37,6 +37,10 @@ class MDNode; struct RangeSpan { const MCSymbol *Begin; const MCSymbol *End; + + bool operator==(const RangeSpan &Other) const { + return Begin == Other.Begin && End == Other.End; + } }; struct RangeSpanList { diff --git a/llvm/test/DebugInfo/Generic/debug-ranges-duplication.ll b/llvm/test/DebugInfo/Generic/debug-ranges-duplication.ll new file mode 100644 index 0000000000000..540400be740a5 --- /dev/null +++ b/llvm/test/DebugInfo/Generic/debug-ranges-duplication.ll @@ -0,0 +1,70 @@ +; RUN: %llc_dwarf -O0 -filetype=obj < %s | llvm-dwarfdump -debug-info - | FileCheck %s +; +; Generated from the following C++ source with: +; clang -S -emit-llvm -g -O2 test.c +; +; /* BEGIN SOURCE */ +; void f1(); +; inline void f2() { +; f1(); +; f1(); +; } +; inline void f3() { +; f2(); +; } +; void f4() { +; f3(); +; f1(); +; } +; /* END SOURCE */ +; +; Minor complication: after generating the LLVM IR, it was manually edited so +; that the 'f1()' call from f3 was reordered to appear between the two inlined +; f1 calls from f2. This causes f2's inlined_subroutine to use DW_AT_ranges. + +; Check that identical debug ranges in succession reuse the same entry in +; .debug_ranges rather than emitting duplicate entries. + +; CHECK: DW_TAG_inlined_subroutine +; CHECK: DW_AT_ranges +; CHECK-SAME: rangelist = 0x[[#%.8X,RANGE:]] +; CHECK: DW_TAG_inlined_subroutine +; CHECK: DW_AT_ranges +; CHECK-SAME: rangelist = 0x[[#RANGE]] + +; Function Attrs: nounwind uwtable +define dso_local void @f4() local_unnamed_addr !dbg !9 { +entry: + tail call void (...) @f1(), !dbg !12 + tail call void (...) @f1(), !dbg !18 + tail call void (...) @f1(), !dbg !17 + ret void, !dbg !19 +} + +declare !dbg !20 void @f1(...) local_unnamed_addr + +!llvm.dbg.cu = !{!0} +!llvm.module.flags = !{!2, !3, !4, !5, !6, !7} +!llvm.ident = !{!8} + +!0 = distinct !DICompileUnit(language: DW_LANG_C11, file: !1, producer: "clang version 20.0.0git (https://github.com/llvm/llvm-project.git 9edd998e10fabfff067b9e6e5b044f85a24d0dd5)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, splitDebugInlining: false, nameTableKind: None) +!1 = !DIFile(filename: "test.c", directory: "/home/khuey/dev/llvm-project", checksumkind: CSK_MD5, checksum: "4510feb241cf078af753e3dc13205127") +!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 20.0.0git (https://github.com/llvm/llvm-project.git 9edd998e10fabfff067b9e6e5b044f85a24d0dd5)"} +!9 = distinct !DISubprogram(name: "f4", scope: !1, file: !1, line: 9, type: !10, scopeLine: 9, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0) +!10 = !DISubroutineType(types: !11) +!11 = !{null} +!12 = !DILocation(line: 3, column: 3, scope: !13, inlinedAt: !14) +!13 = distinct !DISubprogram(name: "f2", scope: !1, file: !1, line: 2, type: !10, scopeLine: 2, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0) +!14 = distinct !DILocation(line: 7, column: 3, scope: !15, inlinedAt: !16) +!15 = distinct !DISubprogram(name: "f3", scope: !1, file: !1, line: 6, type: !10, scopeLine: 6, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0) +!16 = distinct !DILocation(line: 10, column: 3, scope: !9) +!17 = !DILocation(line: 4, column: 3, scope: !13, inlinedAt: !14) +!18 = !DILocation(line: 11, column: 3, scope: !9) +!19 = !DILocation(line: 12, column: 1, scope: !9) +!20 = !DISubprogram(name: "f1", scope: !1, file: !1, line: 1, type: !10, spFlags: DISPFlagOptimized)