Index: llvm/lib/CodeGen/AsmPrinter/DebugLocEntry.h =================================================================== --- llvm/lib/CodeGen/AsmPrinter/DebugLocEntry.h +++ llvm/lib/CodeGen/AsmPrinter/DebugLocEntry.h @@ -153,6 +153,7 @@ const MCSymbol *getBeginSym() const { return Begin; } const MCSymbol *getEndSym() const { return End; } + void setEndSym(const MCSymbol *Val) { End = Val; } ArrayRef getValues() const { return Values; } void addValues(ArrayRef Vals) { Values.append(Vals.begin(), Vals.end()); Index: llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp =================================================================== --- llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp +++ llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp @@ -1638,6 +1638,8 @@ bool isSafeForSingleLocation = true; const MachineInstr *StartDebugMI = nullptr; const MachineInstr *EndMI = nullptr; + const MachineInstr *PrevEndLabelInstr = nullptr; + const MachineInstr *CurEndLabelInstr = nullptr; for (auto EB = Entries.begin(), EI = EB, EE = Entries.end(); EI != EE; ++EI) { const MachineInstr *Instr = EI->getInstr(); @@ -1667,6 +1669,10 @@ else EndLabel = getLabelBeforeInsn(std::next(EI)->getInstr()); assert(EndLabel && "Forgot label after instruction ending a range!"); + if (Asm->MF->hasBBSections()) + CurEndLabelInstr = (std::next(EI) == Entries.end()) + ? &Asm->MF->back().back() + : std::next(EI)->getInstr(); if (EI->isDbgValue()) LLVM_DEBUG(dbgs() << "DotDebugLoc: " << *Instr << "\n"); @@ -1723,8 +1729,24 @@ }); auto PrevEntry = std::next(CurEntry); + // Entries in different basic block sections can still be merged. Here, we + // check if the previous entry's end label and the next entry's begin label + // are in adjacent basic block sections and pointing to the end of the + // first section and the beginning of the following section respectively. if (PrevEntry != DebugLoc.rend() && PrevEntry->MergeRanges(*CurEntry)) DebugLoc.pop_back(); + else if (Asm->MF->hasBBSections() && PrevEntry != DebugLoc.rend() && + !PrevEndLabelInstr->getParent()->sameSection(Instr->getParent()) && + PrevEndLabelInstr->getParent()->getNextNode() == + Instr->getParent() && + Asm->MBBSectionRanges[Instr->getParent()->getSectionIDNum()] + .BeginLabel == StartLabel && + PrevEndLabelInstr->getNextNode() == nullptr) { + PrevEntry->setEndSym(CurEntry->getEndSym()); + DebugLoc.pop_back(); + } + if (Asm->MF->hasBBSections()) + PrevEndLabelInstr = CurEndLabelInstr; } // If there's a single entry, safe for a single location, and not part of Index: llvm/test/DebugInfo/X86/basic-block-sections-debug-loc.ll =================================================================== --- /dev/null +++ llvm/test/DebugInfo/X86/basic-block-sections-debug-loc.ll @@ -0,0 +1,86 @@ +;; The dbg value for buflen in the non-entry basic block spans the entire +;; function and is emitted as DW_AT_const_value. Even with basic block +;; sections, this can be done as the entire function is represented as ranges. + +; RUN: llc %s --dwarf-version=4 --basic-block-sections=none -filetype=obj -o %t +; RUN: llvm-dwarfdump %t | FileCheck %s +; RUN: llc %s --dwarf-version=4 --basic-block-sections=all -filetype=obj -o %t +; RUN: llvm-dwarfdump %t | FileCheck %s + +; CHECK: DW_AT_const_value (157) +; CHECK-NEXT: DW_AT_name ("buflen") + +target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128" +target triple = "x86_64-grtev4-linux-gnu" + +define dso_local void @_ZL4ncatPcjz(i8* %0, i32 %1, ...) unnamed_addr #0 align 32 !dbg !22 { +.critedge3: + call void @llvm.dbg.value(metadata i32 157, metadata !27, metadata !DIExpression()), !dbg !46 + call void @llvm.va_start(i8* nonnull undef), !dbg !47 + br label %2 + +2: ; preds = %2, %.critedge3 + br label %2 +} + +; Function Attrs: nounwind +declare void @llvm.va_start(i8*) #1 + +; Function Attrs: nounwind readnone speculatable willreturn +declare void @llvm.dbg.value(metadata, metadata, metadata) #2 + +attributes #0 = { "use-soft-float"="false" } +attributes #1 = { nounwind } +attributes #2 = { nounwind readnone speculatable willreturn } + +!llvm.dbg.cu = !{!0} +!llvm.module.flags = !{!20, !21} + +!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !1, producer: "clang", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, retainedTypes: !2) +!1 = !DIFile(filename: "bug.cpp", directory: "/proc/self/cwd") +!2 = !{!3, !6, !9, !10, !11, !13, !16, !17, !15} +!3 = !DIDerivedType(tag: DW_TAG_typedef, name: "int32_t", file: !4, line: 38, baseType: !5) +!4 = !DIFile(filename: "stdint.h", directory: "/proc/self/cwd") +!5 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed) +!6 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !7, size: 64) +!7 = !DIDerivedType(tag: DW_TAG_const_type, baseType: !8) +!8 = !DIBasicType(name: "char", size: 8, encoding: DW_ATE_unsigned_char) +!9 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !8, size: 64) +!10 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: null, size: 64) +!11 = !DIDerivedType(tag: DW_TAG_typedef, name: "uint32_t", file: !4, line: 51, baseType: !12) +!12 = !DIBasicType(name: "unsigned int", size: 32, encoding: DW_ATE_unsigned) +!13 = !DIDerivedType(tag: DW_TAG_typedef, name: "UChar", file: !14, line: 372, baseType: !15) +!14 = !DIFile(filename: "umachine.h", directory: "/proc/self/cwd") +!15 = !DIBasicType(name: "char16_t", size: 16, encoding: DW_ATE_UTF) +!16 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !3, size: 64) +!17 = !DIDerivedType(tag: DW_TAG_typedef, name: "UBool", file: !14, line: 261, baseType: !18) +!18 = !DIDerivedType(tag: DW_TAG_typedef, name: "int8_t", file: !4, line: 36, baseType: !19) +!19 = !DIBasicType(name: "signed char", size: 8, encoding: DW_ATE_signed_char) +!20 = !{i32 2, !"Debug Info Version", i32 3} +!21 = !{i32 7, !"PIC Level", i32 2} +!22 = distinct !DISubprogram(name: "ncat", linkageName: "_ZL4ncatPcjz", scope: !1, file: !1, line: 37, type: !23, scopeLine: 37, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !25) +!23 = !DISubroutineType(types: !24) +!24 = !{!3, !9, !11, null} +!25 = !{!26, !27, !28, !41, !42, !43, !44} +!26 = !DILocalVariable(name: "buffer", arg: 1, scope: !22, file: !1, line: 37, type: !9) +!27 = !DILocalVariable(name: "buflen", arg: 2, scope: !22, file: !1, line: 37, type: !11) +!28 = !DILocalVariable(name: "args", scope: !22, file: !1, line: 38, type: !29) +!29 = !DIDerivedType(tag: DW_TAG_typedef, name: "va_list", file: !30, line: 14, baseType: !31) +!30 = !DIFile(filename: "stdarg.h", directory: "/proc/self/cwd") +!31 = !DIDerivedType(tag: DW_TAG_typedef, name: "__builtin_va_list", file: !1, line: 38, baseType: !32) +!32 = !DICompositeType(tag: DW_TAG_array_type, baseType: !33, size: 192, elements: !39) +!33 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "__va_list_tag", file: !1, line: 38, size: 192, flags: DIFlagTypePassByValue, elements: !34, identifier: "_ZTS13__va_list_tag") +!34 = !{!35, !36, !37, !38} +!35 = !DIDerivedType(tag: DW_TAG_member, name: "gp_offset", scope: !33, file: !1, line: 38, baseType: !12, size: 32) +!36 = !DIDerivedType(tag: DW_TAG_member, name: "fp_offset", scope: !33, file: !1, line: 38, baseType: !12, size: 32, offset: 32) +!37 = !DIDerivedType(tag: DW_TAG_member, name: "overflow_arg_area", scope: !33, file: !1, line: 38, baseType: !10, size: 64, offset: 64) +!38 = !DIDerivedType(tag: DW_TAG_member, name: "reg_save_area", scope: !33, file: !1, line: 38, baseType: !10, size: 64, offset: 128) +!39 = !{!40} +!40 = !DISubrange(count: 1) +!41 = !DILocalVariable(name: "str", scope: !22, file: !1, line: 39, type: !9) +!42 = !DILocalVariable(name: "p", scope: !22, file: !1, line: 40, type: !9) +!43 = !DILocalVariable(name: "e", scope: !22, file: !1, line: 41, type: !6) +!44 = !DILocalVariable(name: "c", scope: !45, file: !1, line: 49, type: !8) +!45 = distinct !DILexicalBlock(scope: !22, file: !1, line: 48, column: 45) +!46 = !DILocation(line: 0, scope: !22) +!47 = !DILocation(line: 47, column: 3, scope: !22)