From faf70c1e2360911a9c7419046601b8fdb5d558e4 Mon Sep 17 00:00:00 2001 From: Reid Kleckner Date: Tue, 7 Jun 2016 00:02:03 +0000 Subject: [PATCH] Re-land "[codeview] Emit information about global variables" This reverts commit r271962 and reinstantes r271957. MSVC's linker doesn't appear to like it if you have an empty symbol substream, so only open a symbol substream if we're going to emit something about globals into it. Makes check-asan pass. llvm-svn: 271965 --- lib/CodeGen/AsmPrinter/CodeViewDebug.cpp | 111 +++++++++++++---- lib/CodeGen/AsmPrinter/CodeViewDebug.h | 11 ++ test/DebugInfo/COFF/globals.ll | 146 +++++++++++++++++++++++ 3 files changed, 247 insertions(+), 21 deletions(-) create mode 100644 test/DebugInfo/COFF/globals.ll diff --git a/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp b/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp index 57fa54a5e9b..db1dc519ed5 100644 --- a/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp +++ b/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp @@ -232,7 +232,7 @@ void CodeViewDebug::emitCodeViewMagicVersion() { } void CodeViewDebug::endModule() { - if (FnDebugInfo.empty()) + if (!Asm || !MMI->hasDebugInfo()) return; assert(Asm != nullptr); @@ -242,13 +242,18 @@ void CodeViewDebug::endModule() { // of the payload followed by the payload itself. The subsections are 4-byte // aligned. - // Make a subsection for all the inlined subprograms. + // Use the generic .debug$S section, and make a subsection for all the inlined + // subprograms. + switchToDebugSectionForSymbol(nullptr); emitInlineeLinesSubsection(); // Emit per-function debug information. for (auto &P : FnDebugInfo) emitDebugInfoForFunction(P.first, P.second); + // Emit global variable debug information. + emitDebugInfoForGlobals(); + // Switch back to the generic .debug$S section after potentially processing // comdat symbol sections. switchToDebugSectionForSymbol(nullptr); @@ -326,17 +331,9 @@ void CodeViewDebug::emitInlineeLinesSubsection() { if (InlinedSubprograms.empty()) return; - // Use the generic .debug$S section. - switchToDebugSectionForSymbol(nullptr); - - MCSymbol *InlineBegin = MMI->getContext().createTempSymbol(), - *InlineEnd = MMI->getContext().createTempSymbol(); OS.AddComment("Inlinee lines subsection"); - OS.EmitIntValue(unsigned(ModuleSubstreamKind::InlineeLines), 4); - OS.AddComment("Subsection size"); - OS.emitAbsoluteSymbolDiff(InlineEnd, InlineBegin, 4); - OS.EmitLabel(InlineBegin); + MCSymbol *InlineEnd = beginCVSubsection(ModuleSubstreamKind::InlineeLines); // We don't provide any extra file info. // FIXME: Find out if debuggers use this info. @@ -363,7 +360,7 @@ void CodeViewDebug::emitInlineeLinesSubsection() { OS.EmitIntValue(SP->getLine(), 4); } - OS.EmitLabel(InlineEnd); + endCVSubsection(InlineEnd); } void CodeViewDebug::collectInlineSiteChildren( @@ -467,13 +464,8 @@ void CodeViewDebug::emitDebugInfoForFunction(const Function *GV, FuncName = GlobalValue::getRealLinkageName(GV->getName()); // Emit a symbol subsection, required by VS2012+ to find function boundaries. - MCSymbol *SymbolsBegin = MMI->getContext().createTempSymbol(), - *SymbolsEnd = MMI->getContext().createTempSymbol(); OS.AddComment("Symbol subsection for " + Twine(FuncName)); - OS.EmitIntValue(unsigned(ModuleSubstreamKind::Symbols), 4); - OS.AddComment("Subsection size"); - OS.emitAbsoluteSymbolDiff(SymbolsEnd, SymbolsBegin, 4); - OS.EmitLabel(SymbolsBegin); + MCSymbol *SymbolsEnd = beginCVSubsection(ModuleSubstreamKind::Symbols); { MCSymbol *ProcRecordBegin = MMI->getContext().createTempSymbol(), *ProcRecordEnd = MMI->getContext().createTempSymbol(); @@ -532,9 +524,7 @@ void CodeViewDebug::emitDebugInfoForFunction(const Function *GV, OS.AddComment("Record kind: S_PROC_ID_END"); OS.EmitIntValue(unsigned(SymbolKind::S_PROC_ID_END), 2); } - OS.EmitLabel(SymbolsEnd); - // Every subsection must be aligned to a 4-byte boundary. - OS.EmitValueToAlignment(4); + endCVSubsection(SymbolsEnd); // We have an assembler directive that takes care of the whole line table. OS.EmitCVLinetableDirective(FI.FuncId, Fn, FI.End); @@ -1272,3 +1262,82 @@ void CodeViewDebug::beginInstruction(const MachineInstr *MI) { return; maybeRecordLocation(DL, Asm->MF); } + +MCSymbol *CodeViewDebug::beginCVSubsection(ModuleSubstreamKind Kind) { + MCSymbol *BeginLabel = MMI->getContext().createTempSymbol(), + *EndLabel = MMI->getContext().createTempSymbol(); + OS.EmitIntValue(unsigned(Kind), 4); + OS.AddComment("Subsection size"); + OS.emitAbsoluteSymbolDiff(EndLabel, BeginLabel, 4); + OS.EmitLabel(BeginLabel); + return EndLabel; +} + +void CodeViewDebug::endCVSubsection(MCSymbol *EndLabel) { + OS.EmitLabel(EndLabel); + // Every subsection must be aligned to a 4-byte boundary. + OS.EmitValueToAlignment(4); +} + +void CodeViewDebug::emitDebugInfoForGlobals() { + NamedMDNode *CUs = MMI->getModule()->getNamedMetadata("llvm.dbg.cu"); + for (const MDNode *Node : CUs->operands()) { + const auto *CU = cast(Node); + + // First, emit all globals that are not in a comdat in a single symbol + // substream. MSVC doesn't like it if the substream is empty, so only open + // it if we have at least one global to emit. + switchToDebugSectionForSymbol(nullptr); + MCSymbol *EndLabel = nullptr; + for (const DIGlobalVariable *G : CU->getGlobalVariables()) { + if (const auto *GV = dyn_cast(G->getVariable())) + if (!GV->hasComdat()) { + if (!EndLabel) { + OS.AddComment("Symbol subsection for globals"); + EndLabel = beginCVSubsection(ModuleSubstreamKind::Symbols); + } + emitDebugInfoForGlobal(G, Asm->getSymbol(GV)); + } + } + if (EndLabel) + endCVSubsection(EndLabel); + + // Second, emit each global that is in a comdat into its own .debug$S + // section along with its own symbol substream. + for (const DIGlobalVariable *G : CU->getGlobalVariables()) { + if (const auto *GV = dyn_cast(G->getVariable())) { + if (GV->hasComdat()) { + MCSymbol *GVSym = Asm->getSymbol(GV); + OS.AddComment("Symbol subsection for " + + Twine(GlobalValue::getRealLinkageName(GV->getName()))); + switchToDebugSectionForSymbol(GVSym); + EndLabel = beginCVSubsection(ModuleSubstreamKind::Symbols); + emitDebugInfoForGlobal(G, GVSym); + endCVSubsection(EndLabel); + } + } + } + } +} + +void CodeViewDebug::emitDebugInfoForGlobal(const DIGlobalVariable *DIGV, + MCSymbol *GVSym) { + // DataSym record, see SymbolRecord.h for more info. + // FIXME: Thread local data, etc + MCSymbol *DataBegin = MMI->getContext().createTempSymbol(), + *DataEnd = MMI->getContext().createTempSymbol(); + OS.AddComment("Record length"); + OS.emitAbsoluteSymbolDiff(DataEnd, DataBegin, 2); + OS.EmitLabel(DataBegin); + OS.AddComment("Record kind: S_GDATA32"); + OS.EmitIntValue(unsigned(SymbolKind::S_GDATA32), 2); + OS.AddComment("Type"); + OS.EmitIntValue(getCompleteTypeIndex(DIGV->getType()).getIndex(), 4); + OS.AddComment("DataOffset"); + OS.EmitCOFFSecRel32(GVSym); + OS.AddComment("Segment"); + OS.EmitCOFFSectionIndex(GVSym); + OS.AddComment("Name"); + emitNullTerminatedSymbolName(OS, DIGV->getName()); + OS.EmitLabel(DataEnd); +} diff --git a/lib/CodeGen/AsmPrinter/CodeViewDebug.h b/lib/CodeGen/AsmPrinter/CodeViewDebug.h index 208ff33b964..69c9c966f93 100644 --- a/lib/CodeGen/AsmPrinter/CodeViewDebug.h +++ b/lib/CodeGen/AsmPrinter/CodeViewDebug.h @@ -169,6 +169,17 @@ class LLVM_LIBRARY_VISIBILITY CodeViewDebug : public DebugHandlerBase { void emitDebugInfoForFunction(const Function *GV, FunctionInfo &FI); + void emitDebugInfoForGlobals(); + + void emitDebugInfoForGlobal(const DIGlobalVariable *DIGV, MCSymbol *GVSym); + + /// Opens a subsection of the given kind in a .debug$S codeview section. + /// Returns an end label for use with endCVSubsection when the subsection is + /// finished. + MCSymbol *beginCVSubsection(codeview::ModuleSubstreamKind Kind); + + void endCVSubsection(MCSymbol *EndLabel); + void emitInlinedCallSite(const FunctionInfo &FI, const DILocation *InlinedAt, const InlineSite &Site); diff --git a/test/DebugInfo/COFF/globals.ll b/test/DebugInfo/COFF/globals.ll new file mode 100644 index 00000000000..1fd33863839 --- /dev/null +++ b/test/DebugInfo/COFF/globals.ll @@ -0,0 +1,146 @@ +; RUN: llc < %s | FileCheck %s --check-prefix=ASM +; RUN: llc < %s -filetype=obj | llvm-readobj - -codeview | FileCheck %s --check-prefix=OBJ + +; C++ source to regenerate: +; $ cat t.cpp +; int first; +; template struct A { static const int comdat = 3; }; +; const int *middle = &A::comdat; +; int last; +; $ clang t.cpp -S -emit-llvm -g -gcodeview -o t.ll + +; ASM: .section .debug$S,"dr" +; ASM: .p2align 2 +; ASM: .long 4 # Debug section magic + +; ASM: .short {{.*-.*}} # Record length +; ASM: .short 4365 # Record kind: S_GDATA32 +; ASM: .long 116 # Type +; ASM: .secrel32 "?first@@3HA" # DataOffset +; ASM: .secidx "?first@@3HA" # Segment +; ASM: .asciz "first" # Name + +; ASM: .short {{.*-.*}} # Record length +; ASM: .short 4365 # Record kind: S_GDATA32 +; ASM: .long 4097 # Type +; ASM: .secrel32 "?middle@@3PEBHEB" # DataOffset +; ASM: .secidx "?middle@@3PEBHEB" # Segment +; ASM: .asciz "middle" # Name + +; ASM: .short {{.*-.*}} # Record length +; ASM: .short 4365 # Record kind: S_GDATA32 +; ASM: .long 116 # Type +; ASM: .secrel32 "?last@@3HA" # DataOffset +; ASM: .secidx "?last@@3HA" # Segment +; ASM: .asciz "last" # Name + +; ASM: .section .debug$S,"dr",associative,"?comdat@?$A@X@@2HB" +; ASM: .p2align 2 +; ASM: .long 4 # Debug section magic + +; ASM: .short {{.*-.*}} # Record length +; ASM: .short 4365 # Record kind: S_GDATA32 +; ASM: .long 4096 # Type +; ASM: .secrel32 "?comdat@?$A@X@@2HB" # DataOffset +; ASM: .secidx "?comdat@?$A@X@@2HB" # Segment +; ASM: .asciz "comdat" # Name + +; OBJ: CodeViewTypes [ +; OBJ: Section: .debug$T +; OBJ: Magic: 0x4 +; OBJ: Modifier (0x1000) { +; OBJ: TypeLeafKind: LF_MODIFIER (0x1001) +; OBJ: ModifiedType: int (0x74) +; OBJ: Modifiers [ (0x1) +; OBJ: Const (0x1) +; OBJ: ] +; OBJ: } +; OBJ: Pointer (0x1001) { +; OBJ: TypeLeafKind: LF_POINTER (0x1002) +; OBJ: PointeeType: const int (0x1000) +; OBJ: PointerAttributes: 0x1000C +; OBJ: PtrType: Near64 (0xC) +; OBJ: PtrMode: Pointer (0x0) +; OBJ: IsFlat: 0 +; OBJ: IsConst: 0 +; OBJ: IsVolatile: 0 +; OBJ: IsUnaligned: 0 +; OBJ: } +; OBJ: ] + +; OBJ: CodeViewDebugInfo [ +; OBJ: Section: .debug$S +; OBJ: Magic: 0x4 +; OBJ: Subsection [ +; OBJ: SubSectionType: Symbols (0xF1) +; OBJ: DataSym { +; OBJ: DataOffset: ?first@@3HA+0x0 +; OBJ: Type: int (0x74) +; OBJ: DisplayName: first +; OBJ: LinkageName: ?first@@3HA +; OBJ: } +; OBJ: DataSym { +; OBJ: DataOffset: ?middle@@3PEBHEB+0x0 +; OBJ: Type: const int* (0x1001) +; OBJ: DisplayName: middle +; OBJ: LinkageName: ?middle@@3PEBHEB +; OBJ: } +; OBJ: DataSym { +; OBJ: DataOffset: ?last@@3HA+0x0 +; OBJ: Type: int (0x74) +; OBJ: DisplayName: last +; OBJ: LinkageName: ?last@@3HA +; OBJ: } +; OBJ: ] +; OBJ: ] +; OBJ: CodeViewDebugInfo [ +; OBJ: Section: .debug$S (6) +; OBJ: Magic: 0x4 +; OBJ: Subsection [ +; OBJ: SubSectionType: Symbols (0xF1) +; OBJ: SubSectionSize: 0x15 +; OBJ: DataSym { +; OBJ: DataOffset: ?comdat@?$A@X@@2HB+0x0 +; OBJ: Type: const int (0x1000) +; OBJ: DisplayName: comdat +; OBJ: LinkageName: ?comdat@?$A@X@@2HB +; OBJ: } +; OBJ: ] +; OBJ: ] + +; ModuleID = 't.cpp' +source_filename = "t.cpp" +target datalayout = "e-m:w-i64:64-f80:128-n8:16:32:64-S128" +target triple = "x86_64-pc-windows-msvc19.0.23918" + +$"\01?comdat@?$A@X@@2HB" = comdat any + +@"\01?first@@3HA" = global i32 0, align 4 +@"\01?comdat@?$A@X@@2HB" = linkonce_odr constant i32 3, comdat, align 4 +@"\01?middle@@3PEBHEB" = global i32* @"\01?comdat@?$A@X@@2HB", align 8 +@"\01?last@@3HA" = global i32 0, align 4 + +!llvm.dbg.cu = !{!0} +!llvm.module.flags = !{!16, !17, !18} +!llvm.ident = !{!19} + +!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 3.9.0 (trunk 271937)", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, globals: !3) +!1 = !DIFile(filename: "t.cpp", directory: "D:\5Csrc\5Cllvm\5Cbuild") +!2 = !{} +!3 = !{!4, !6, !13, !15} +!4 = distinct !DIGlobalVariable(name: "first", linkageName: "\01?first@@3HA", scope: !0, file: !1, line: 1, type: !5, isLocal: false, isDefinition: true, variable: i32* @"\01?first@@3HA") +!5 = !DIBasicType(name: "int", size: 32, align: 32, encoding: DW_ATE_signed) +!6 = distinct !DIGlobalVariable(name: "comdat", linkageName: "\01?comdat@?$A@X@@2HB", scope: !0, file: !1, line: 2, type: !7, isLocal: false, isDefinition: true, variable: i32* @"\01?comdat@?$A@X@@2HB", declaration: !8) +!7 = !DIDerivedType(tag: DW_TAG_const_type, baseType: !5) +!8 = !DIDerivedType(tag: DW_TAG_member, name: "comdat", scope: !9, file: !1, line: 2, baseType: !7, flags: DIFlagStaticMember, extraData: i32 3) +!9 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "A", file: !1, line: 2, size: 8, align: 8, elements: !10, templateParams: !11) +!10 = !{!8} +!11 = !{!12} +!12 = !DITemplateTypeParameter(name: "T", type: null) +!13 = distinct !DIGlobalVariable(name: "middle", linkageName: "\01?middle@@3PEBHEB", scope: !0, file: !1, line: 3, type: !14, isLocal: false, isDefinition: true, variable: i32** @"\01?middle@@3PEBHEB") +!14 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !7, size: 64, align: 64) +!15 = distinct !DIGlobalVariable(name: "last", linkageName: "\01?last@@3HA", scope: !0, file: !1, line: 4, type: !5, isLocal: false, isDefinition: true, variable: i32* @"\01?last@@3HA") +!16 = !{i32 2, !"CodeView", i32 1} +!17 = !{i32 2, !"Debug Info Version", i32 3} +!18 = !{i32 1, !"PIC Level", i32 2} +!19 = !{!"clang version 3.9.0 (trunk 271937)"}