Commit 8f870305 authored by Hans Wennborg's avatar Hans Wennborg
Browse files

Merging r294318: 

------------------------------------------------------------------------
r294318 | adrian | 2017-02-07 09:35:41 -0800 (Tue, 07 Feb 2017) | 12 lines

Fix the bitcode upgrade for DIGlobalVariable in a DIImportedEntity context.

The bitcode upgrade for DIGlobalVariable unconditionally wrapped
DIGlobalVariables in a DIGlobalVariableExpression. When a
DIGlobalVariable is referenced by a DIImportedEntity, however, this is
wrong. This patch fixes the bitcode upgrade by deferring the creation
of DIGlobalVariableExpressions until we know the context of the
DIGlobalVariable.

<rdar://problem/30134279>

Differential Revision: https://reviews.llvm.org/D29349
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llvm-svn: 294352
parent 16f21230

llvm/lib/Bitcode/Reader/MetadataLoader.cpp

+51 −5
Original line number Diff line number Diff line
@@ -448,6 +448,7 @@ class MetadataLoader::MetadataLoaderImpl { 


  bool StripTBAA = false;

  bool HasSeenOldLoopTags = false;

  bool NeedUpgradeToDIGlobalVariableExpression = false;



  /// True if metadata is being parsed for a module being ThinLTO imported.

  bool IsImporting = false;
@@ -473,6 +474,45 @@ class MetadataLoader::MetadataLoaderImpl { 
    CUSubprograms.clear();

  }



  /// Upgrade old-style bare DIGlobalVariables to DIGlobalVariableExpressions.

  void upgradeCUVariables() {

    if (!NeedUpgradeToDIGlobalVariableExpression)

      return;



    // Upgrade list of variables attached to the CUs.

    if (NamedMDNode *CUNodes = TheModule.getNamedMetadata("llvm.dbg.cu"))

      for (unsigned I = 0, E = CUNodes->getNumOperands(); I != E; ++I) {

        auto *CU = cast<DICompileUnit>(CUNodes->getOperand(I));

        if (auto *GVs = dyn_cast_or_null<MDTuple>(CU->getRawGlobalVariables()))

          for (unsigned I = 0; I < GVs->getNumOperands(); I++)

            if (auto *GV =

                    dyn_cast_or_null<DIGlobalVariable>(GVs->getOperand(I))) {

              auto *DGVE =

                  DIGlobalVariableExpression::getDistinct(Context, GV, nullptr);

              GVs->replaceOperandWith(I, DGVE);

            }

      }



    // Upgrade variables attached to globals.

    for (auto &GV : TheModule.globals()) {

      SmallVector<MDNode *, 1> MDs, NewMDs;

      GV.getMetadata(LLVMContext::MD_dbg, MDs);

      GV.eraseMetadata(LLVMContext::MD_dbg);

      for (auto *MD : MDs)

        if (auto *DGV = dyn_cast_or_null<DIGlobalVariable>(MD)) {

          auto *DGVE =

              DIGlobalVariableExpression::getDistinct(Context, DGV, nullptr);

          GV.addMetadata(LLVMContext::MD_dbg, *DGVE);

        } else

          GV.addMetadata(LLVMContext::MD_dbg, *MD);

    }

  }



  void upgradeDebugInfo() {

    upgradeCUSubprograms();

    upgradeCUVariables();

  }



public:

  MetadataLoaderImpl(BitstreamCursor &Stream, Module &TheModule,

                     BitcodeReaderValueList &ValueList,
@@ -726,7 +766,7 @@ Error MetadataLoader::MetadataLoaderImpl::parseMetadata(bool ModuleLevel) { 
      // Reading the named metadata created forward references and/or

      // placeholders, that we flush here.

      resolveForwardRefsAndPlaceholders(Placeholders);

      upgradeCUSubprograms();

      upgradeDebugInfo();

      // Return at the beginning of the block, since it is easy to skip it

      // entirely from there.

      Stream.ReadBlockEnd(); // Pop the abbrev block context.
@@ -750,7 +790,7 @@ Error MetadataLoader::MetadataLoaderImpl::parseMetadata(bool ModuleLevel) { 
      return error("Malformed block");

    case BitstreamEntry::EndBlock:

      resolveForwardRefsAndPlaceholders(Placeholders);

      upgradeCUSubprograms();

      upgradeDebugInfo();

      return Error::success();

    case BitstreamEntry::Record:

      // The interesting case.
@@ -1420,11 +1460,17 @@ Error MetadataLoader::MetadataLoaderImpl::parseOneMetadata( 
           getDITypeRefOrNull(Record[6]), Record[7], Record[8],

           getMDOrNull(Record[10]), AlignInBits));



      auto *DGVE = DIGlobalVariableExpression::getDistinct(Context, DGV, Expr);

      MetadataList.assignValue(DGVE, NextMetadataNo);

      NextMetadataNo++;

      DIGlobalVariableExpression *DGVE = nullptr;

      if (Attach || Expr)

        DGVE = DIGlobalVariableExpression::getDistinct(Context, DGV, Expr);

      else

        NeedUpgradeToDIGlobalVariableExpression = true;

      if (Attach)

        Attach->addDebugInfo(DGVE);



      auto *MDNode = Expr ? cast<Metadata>(DGVE) : cast<Metadata>(DGV);

      MetadataList.assignValue(MDNode, NextMetadataNo);

      NextMetadataNo++;

    } else

      return error("Invalid record");

llvm/test/Bitcode/DIGlobalVariableExpression.ll

+9 −4
Original line number Diff line number Diff line
@@ -7,12 +7,16 @@ 
; CHECK: @h = common global i32 0, align 4, !dbg ![[H:[0-9]+]]

; CHECK: ![[G]] = {{.*}}!DIGlobalVariableExpression(var: ![[GVAR:[0-9]+]], expr: ![[GEXPR:[0-9]+]])

; CHECK: ![[GVAR]] = distinct !DIGlobalVariable(name: "g",

; CHECK: DICompileUnit({{.*}}, imports: ![[IMPORTS:[0-9]+]]

; CHECK: !DIGlobalVariableExpression(var: ![[CVAR:[0-9]+]], expr: ![[CEXPR:[0-9]+]])

; CHECK: ![[CVAR]] = distinct !DIGlobalVariable(name: "c",

; CHECK: ![[CEXPR]] = !DIExpression(DW_OP_constu, 23, DW_OP_stack_value)

; CHECK: ![[H]] = {{.*}}!DIGlobalVariableExpression(var: ![[HVAR:[0-9]+]])

; CHECK: ![[HVAR]] = distinct !DIGlobalVariable(name: "h",

; CHECK: ![[HVAR:[0-9]+]] = distinct !DIGlobalVariable(name: "h",

; CHECK: ![[IMPORTS]] = !{![[CIMPORT:[0-9]+]]}

; CHECK: ![[CIMPORT]] = !DIImportedEntity({{.*}}entity: ![[HVAR]]

; CHECK: ![[GEXPR]] = !DIExpression(DW_OP_plus, 1)

; CHECK: ![[H]] = {{.*}}!DIGlobalVariableExpression(var: ![[HVAR]])



@g = common global i32 0, align 4, !dbg !0

@h = common global i32 0, align 4, !dbg !11
@@ -21,9 +25,9 @@ 
!llvm.ident = !{!9}



!0 = distinct !DIGlobalVariable(name: "g", scope: !1, file: !2, line: 1, type: !5, isLocal: false, isDefinition: true, expr: !DIExpression(DW_OP_plus, 1))

!1 = distinct !DICompileUnit(language: DW_LANG_C99, file: !2, producer: "clang version 4.0.0 (trunk 286129) (llvm/trunk 286128)", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !3, globals: !4)

!1 = distinct !DICompileUnit(language: DW_LANG_C99, file: !2, producer: "clang version 4.0.0 (trunk 286129) (llvm/trunk 286128)", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, globals: !4, imports: !3)

!2 = !DIFile(filename: "a.c", directory: "/")

!3 = !{}

!3 = !{!12}

!4 = !{!0, !10, !11}

!5 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)

!6 = !{i32 2, !"Dwarf Version", i32 4}
@@ -32,3 +36,4 @@ 
!9 = !{!"clang version 4.0.0 (trunk 286129) (llvm/trunk 286128)"}

!10 = distinct !DIGlobalVariable(name: "c", scope: !1, file: !2, line: 1, type: !5, isLocal: false, isDefinition: true, expr: !DIExpression(DW_OP_constu, 23, DW_OP_stack_value))

!11 = distinct !DIGlobalVariable(name: "h", scope: !1, file: !2, line: 2, type: !5, isLocal: false, isDefinition: true)

!12 = !DIImportedEntity(tag: DW_TAG_imported_declaration, line: 1, scope: !1, entity: !11)

llvm/test/Bitcode/dityperefs-3.8.ll

+7 −8
Original line number Diff line number Diff line
@@ -18,14 +18,13 @@ 
; CHECK-NEXT: !7 = !DILocalVariable(name: "V1", scope: !6, type: !2)

; CHECK-NEXT: !8 = !DIObjCProperty(name: "P1", type: !1)

; CHECK-NEXT: !9 = !DITemplateTypeParameter(type: !1)

; CHECK-NEXT: !10 = distinct !DIGlobalVariableExpression(var: !11)

; CHECK-NEXT: !11 = !DIGlobalVariable(name: "G",{{.*}} type: !1,

; CHECK-NEXT: !12 = !DITemplateValueParameter(type: !1, value: i32* @G1)

; CHECK-NEXT: !13 = !DIImportedEntity(tag: DW_TAG_imported_module, name: "T2", scope: !0, entity: !1)

; CHECK-NEXT: !14 = !DICompositeType(tag: DW_TAG_structure_type, name: "T3", file: !0, elements: !15, identifier: "T3")

; CHECK-NEXT: !15 = !{!16}

; CHECK-NEXT: !16 = !DISubprogram(scope: !14,

; CHECK-NEXT: !17 = !DIDerivedType(tag: DW_TAG_ptr_to_member_type,{{.*}} extraData: !14)

; CHECK-NEXT: !10 = !DIGlobalVariable(name: "G",{{.*}} type: !1,

; CHECK-NEXT: !11 = !DITemplateValueParameter(type: !1, value: i32* @G1)

; CHECK-NEXT: !12 = !DIImportedEntity(tag: DW_TAG_imported_module, name: "T2", scope: !0, entity: !1)

; CHECK-NEXT: !13 = !DICompositeType(tag: DW_TAG_structure_type, name: "T3", file: !0, elements: !14, identifier: "T3")

; CHECK-NEXT: !14 = !{!15}

; CHECK-NEXT: !15 = !DISubprogram(scope: !13,

; CHECK-NEXT: !16 = !DIDerivedType(tag: DW_TAG_ptr_to_member_type,{{.*}} extraData: !13)



!0 = !DIFile(filename: "path/to/file", directory: "/path/to/dir")

!1 = !DICompositeType(tag: DW_TAG_structure_type, name: "T1", file: !0, identifier: "T1")