Index: llvm/include/llvm/MC/MCDwarf.h =================================================================== --- llvm/include/llvm/MC/MCDwarf.h +++ llvm/include/llvm/MC/MCDwarf.h @@ -260,7 +260,8 @@ return cantFail(Header.tryGetFile(Directory, FileName, Checksum, Source)); } - void Emit(MCStreamer &MCOS, MCDwarfLineTableParams Params) const; + void Emit(MCStreamer &MCOS, MCDwarfLineTableParams Params, + MCSection *Section) const; }; class MCDwarfLineTable { Index: llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h =================================================================== --- llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h +++ llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h @@ -270,10 +270,6 @@ /// a monolithic sequence of string offsets. bool UseSegmentedStringOffsetsTable; - /// Whether we have emitted any type units with split DWARF (and therefore - /// need to emit a line table to the .dwo file). - bool HasSplitTypeUnits = false; - /// Separated Dwarf Variables /// In general these will all be for bits that are left in the /// original object file, rather than things that are meant Index: llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp =================================================================== --- llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp +++ llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp @@ -2083,11 +2083,9 @@ void DwarfDebug::emitDebugLineDWO() { assert(useSplitDwarf() && "No split dwarf?"); - if (!HasSplitTypeUnits) - return; - Asm->OutStreamer->SwitchSection( + SplitTypeUnitFileTable.Emit( + *Asm->OutStreamer, MCDwarfLineTableParams(), Asm->getObjFileLowering().getDwarfLineDWOSection()); - SplitTypeUnitFileTable.Emit(*Asm->OutStreamer, MCDwarfLineTableParams()); } void DwarfDebug::emitStringOffsetsTableHeaderDWO() { @@ -2202,7 +2200,6 @@ InfoHolder.computeSizeAndOffsetsForUnit(TU.first.get()); InfoHolder.emitUnit(TU.first.get(), useSplitDwarf()); } - HasSplitTypeUnits = useSplitDwarf(); } CU.addDIETypeSignature(RefDie, Signature); } Index: llvm/lib/CodeGen/AsmPrinter/DwarfUnit.h =================================================================== --- llvm/lib/CodeGen/AsmPrinter/DwarfUnit.h +++ llvm/lib/CodeGen/AsmPrinter/DwarfUnit.h @@ -367,6 +367,7 @@ const DIE *Ty; DwarfCompileUnit &CU; MCDwarfDwoLineTable *SplitLineTable; + bool UsedLineTable = false; unsigned getOrCreateSourceID(const DIFile *File) override; bool isDwoUnit() const override; Index: llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp =================================================================== --- llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp +++ llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp @@ -85,8 +85,6 @@ MCDwarfDwoLineTable *SplitLineTable) : DwarfUnit(dwarf::DW_TAG_type_unit, CU.getCUNode(), A, DW, DWU), CU(CU), SplitLineTable(SplitLineTable) { - if (SplitLineTable) - addSectionOffset(getUnitDie(), dwarf::DW_AT_stmt_list, 0); } DwarfUnit::~DwarfUnit() { @@ -300,12 +298,14 @@ } unsigned DwarfTypeUnit::getOrCreateSourceID(const DIFile *File) { - return SplitLineTable - ? SplitLineTable->getFile(File->getDirectory(), - File->getFilename(), - getMD5AsBytes(File), - File->getSource()) - : getCU().getOrCreateSourceID(File); + if (!SplitLineTable) + return getCU().getOrCreateSourceID(File); + if (!UsedLineTable) { + UsedLineTable = true; + addSectionOffset(getUnitDie(), dwarf::DW_AT_stmt_list, 0); + } + return SplitLineTable->getFile(File->getDirectory(), File->getFilename(), + getMD5AsBytes(File), File->getSource()); } void DwarfUnit::addOpAddress(DIELoc &Die, const MCSymbol *Sym) { Index: llvm/lib/MC/MCDwarf.cpp =================================================================== --- llvm/lib/MC/MCDwarf.cpp +++ llvm/lib/MC/MCDwarf.cpp @@ -257,9 +257,12 @@ LineStr->emitSection(MCOS); } -void MCDwarfDwoLineTable::Emit(MCStreamer &MCOS, - MCDwarfLineTableParams Params) const { +void MCDwarfDwoLineTable::Emit(MCStreamer &MCOS, MCDwarfLineTableParams Params, + MCSection *Section) const { + if (Header.MCDwarfFiles.empty()) + return; Optional NoLineStr(None); + MCOS.SwitchSection(Section); MCOS.EmitLabel(Header.Emit(&MCOS, Params, None, NoLineStr).second); } Index: llvm/test/CodeGen/X86/dwarf-split-line-1.ll =================================================================== --- /dev/null +++ llvm/test/CodeGen/X86/dwarf-split-line-1.ll @@ -0,0 +1,42 @@ +; Verify that split type units with no source locations don't have a +; DW_AT_stmt_list attribute, and the .debug_line.dwo section is suppressed. + +; RUN: llc -split-dwarf-file=foo.dwo -dwarf-version=5 -generate-type-units \ +; RUN: -filetype=obj -O0 -mtriple=x86_64-unknown-linux-gnu < %s \ +; RUN: | llvm-dwarfdump -v - | FileCheck %s + +; FIXME: V5 wants type units in .debug_info.dwo not .debug_types.dwo. +; CHECK-NOT: .debug_line.dwo +; CHECK: .debug_types.dwo contents: +; CHECK: 0x00000000: Type Unit: {{.*}} version = 0x0005 unit_type = DW_UT_split_type abbr_offset +; CHECK: 0x00000018: DW_TAG_type_unit +; CHECK-NOT: DW_AT_stmt_list +; CHECK-NOT: DW_AT_decl_file +; CHECK-NOT: .debug_line.dwo + +; ModuleID = 't.cpp' +source_filename = "t.cpp" +target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" +target triple = "x86_64-unknown-linux-gnu" + +%struct.S = type { i32 } + +@s = global %struct.S zeroinitializer, align 4, !dbg !0 + +!llvm.dbg.cu = !{!2} +!llvm.module.flags = !{!10, !11} +!llvm.ident = !{!12} + +!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression()) +!1 = distinct !DIGlobalVariable(name: "s", scope: !2, file: !3, line: 5, type: !6, isLocal: false, isDefinition: true) +!2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "clang version 5.0.0 (trunk 295942)", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5) +!3 = !DIFile(filename: "t.cpp", directory: "/home/probinson/projects/scratch") +!4 = !{} +!5 = !{!0} +!6 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "S", size: 32, elements: !7, identifier: "_ZTS1S") +!7 = !{!8} +!8 = !DIDerivedType(tag: DW_TAG_member, name: "s1", scope: !6, baseType: !9, size: 32) +!9 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed) +!10 = !{i32 2, !"Dwarf Version", i32 4} +!11 = !{i32 2, !"Debug Info Version", i32 3} +!12 = !{!"clang version 5.0.0 (trunk 295942)"} Index: llvm/test/CodeGen/X86/dwarf-split-line-2.ll =================================================================== --- /dev/null +++ llvm/test/CodeGen/X86/dwarf-split-line-2.ll @@ -0,0 +1,57 @@ +; Verify that if we have two split type units, one with source locations and +; one without, the one without locations doesn't have a DW_AT_stmt_list +; attribute, but the other one does and the .debug_line.dwo section is present. + +; RUN: llc -split-dwarf-file=foo.dwo -dwarf-version=5 -generate-type-units \ +; RUN: -filetype=obj -O0 -mtriple=x86_64-unknown-linux-gnu < %s \ +; RUN: | llvm-dwarfdump -v - | FileCheck %s + +; Currently the no-source-location type comes out first. +; FIXME: V5 wants type units in .debug_info.dwo not .debug_types.dwo. +; CHECK: .debug_types.dwo contents: +; CHECK: 0x00000000: Type Unit: {{.*}} name = 'S' +; CHECK-SAME: (next unit at [[TU2:0x[0-9a-f]+]]) +; CHECK: DW_TAG_type_unit +; CHECK-NOT: DW_AT_stmt_list +; CHECK-NOT: DW_AT_decl_file +; CHECK: [[TU2]]: Type Unit: {{.*}} name = 'T' +; CHECK: DW_TAG_type_unit +; CHECK: DW_AT_stmt_list +; CHECK: DW_AT_decl_file + +; CHECK: .debug_line.dwo +; CHECK: file_names[ 1]: + +; ModuleID = 't.cpp' +source_filename = "t.cpp" +target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" +target triple = "x86_64-unknown-linux-gnu" + +%struct.S = type { i32 } +%struct.T = type { i32 } + +@s = global %struct.S zeroinitializer, align 4, !dbg !0 +@t = global %struct.T zeroinitializer, align 4, !dbg !17 + +!llvm.dbg.cu = !{!2} +!llvm.module.flags = !{!10, !11} +!llvm.ident = !{!12} + +!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression()) +!1 = distinct !DIGlobalVariable(name: "s", scope: !2, file: !3, line: 5, type: !6, isLocal: false, isDefinition: true) +!2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "clang version 5.0.0 (trunk 295942)", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5) +!3 = !DIFile(filename: "t.cpp", directory: "/home/probinson/projects/scratch") +!4 = !{} +!5 = !{!0,!17} +!6 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "S", size: 32, elements: !7, identifier: "_ZTS1S") +!7 = !{!8} +!8 = !DIDerivedType(tag: DW_TAG_member, name: "s1", scope: !6, baseType: !9, size: 32) +!9 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed) +!10 = !{i32 2, !"Dwarf Version", i32 4} +!11 = !{i32 2, !"Debug Info Version", i32 3} +!12 = !{!"clang version 5.0.0 (trunk 295942)"} +!13 = distinct !DIGlobalVariable(name: "t", scope: !2, file: !3, line: 10, type: !14, isLocal: false, isDefinition: true) +!14 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "T", file: !3, line: 8, size: 32, elements: !15, identifier: "_ZTS1S") +!15 = !{!16} +!16 = !DIDerivedType(tag: DW_TAG_member, name: "s1", scope: !14, file: !3, line: 9, baseType: !9, size: 32) +!17 = !DIGlobalVariableExpression(var: !13, expr: !DIExpression())