Emit correct linkage-name attribute based on DWARF version.

[probinson]

Summary

There are still 4 tests that check for DW_AT_MIPS_linkage_name,
because they specify DWARF 2 or 3 in the module metadata. So, I didn't
create an explicit version-based test for this.

[dblaikie]

lib/CodeGen/AsmPrinter/DwarfUnit.cpp

1288

Should we pull this out into a utility function somewhere? "addLinkageNameString" ? (it could do the attribute choosing, and the "getRealLinkageName" Call as well, perhaps)

[echristo]

lib/CodeGen/AsmPrinter/DwarfUnit.cpp

1288

Yes. Agreed, it's almost assuredly why it's like this in the first place.

[probinson]

lib/CodeGen/AsmPrinter/DwarfUnit.cpp

1288

Okay. I can add it to DwarfUnit, and it will be usable from DwarfCompileUnit (the other place that adds a linkage name).

[probinson]

Factor out a utility function so the version decision is in one place.

[dblaikie]

Looks good - thanks!

[probinson]

r231880

lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp

if (GV.getGlobal()->isThreadLocal()) {
               DD->useGNUTLSOpcode() ? dwarf::DW_OP_GNU_push_tls_address
                                     : dwarf::DW_OP_form_tls_address);
     } else {
       DD->addArangeLabel(SymbolCU(this, Sym));
       addOpAddress(*Loc, Sym);
     }
 
     addBlock(*VariableDIE, dwarf::DW_AT_location, Loc);
-    // Add the linkage name.
-    StringRef LinkageName = GV.getLinkageName();
-    if (!LinkageName.empty())
-      // From DWARF4: DIEs to which DW_AT_linkage_name may apply include:
-      // TAG_common_block, TAG_constant, TAG_entry_point, TAG_subprogram and
-      // TAG_variable.
-      addString(*VariableDIE,
-                DD->getDwarfVersion() >= 4 ? dwarf::DW_AT_linkage_name
-                                           : dwarf::DW_AT_MIPS_linkage_name,
-                GlobalValue::getRealLinkageName(LinkageName));
+    addLinkageName(*VariableDIE, GV.getLinkageName());
   } else if (const ConstantInt *CI =
                  dyn_cast_or_null<ConstantInt>(GV.getConstant())) {
     addConstantValue(*VariableDIE, CI, GTy);
   } else if (const ConstantExpr *CE = getMergedGlobalExpr(GV.getConstant())) {
     addToAccelTable = true;
     // GV is a merged global.
     DIELoc *Loc = new (DIEValueAllocator) DIELoc();
     Value *Ptr = CE->getOperand(0);

lib/CodeGen/AsmPrinter/DwarfUnit.h

public:
   void addConstantValue(DIE &Die, const APInt &Val, DIType Ty);
   void addConstantValue(DIE &Die, const APInt &Val, bool Unsigned);
   void addConstantValue(DIE &Die, bool Unsigned, uint64_t Val);
 
   /// addConstantFPValue - Add constant value entry in variable DIE.
   void addConstantFPValue(DIE &Die, const MachineOperand &MO);
   void addConstantFPValue(DIE &Die, const ConstantFP *CFP);
 
+  /// \brief Add a linkage name, if it isn't empty.
+  void addLinkageName(DIE &Die, StringRef LinkageName);
+
   /// addTemplateParams - Add template parameters in buffer.
   void addTemplateParams(DIE &Buffer, DIArray TParams);
 
   /// \brief Add register operand.
   /// \returns false if the register does not exist, e.g., because it was never
   /// materialized.
   bool addRegisterOpPiece(DIELoc &TheDie, unsigned Reg,
                           unsigned SizeInBits = 0, unsigned OffsetInBits = 0);

lib/CodeGen/AsmPrinter/DwarfUnit.cpp

for (int i = 0; i < NumBytes; i++) {
     else
       c = Ptr64[(NumBytes - 1 - i) / 8] >> (8 * ((NumBytes - 1 - i) & 7));
     addUInt(*Block, dwarf::DW_FORM_data1, c);
   }
 
   addBlock(Die, dwarf::DW_AT_const_value, Block);
 }
 
+// Add a linkage name to the DIE.
+void DwarfUnit::addLinkageName(DIE &Die, StringRef LinkageName) {
+  if (!LinkageName.empty())
+    addString(Die,
+              DD->getDwarfVersion() >= 4 ? dwarf::DW_AT_linkage_name
+                                         : dwarf::DW_AT_MIPS_linkage_name,
+              GlobalValue::getRealLinkageName(LinkageName));
+}
+
 /// addTemplateParams - Add template parameters into buffer.
 void DwarfUnit::addTemplateParams(DIE &Buffer, DIArray TParams) {
   // Add template parameters.
   for (unsigned i = 0, e = TParams.getNumElements(); i != e; ++i) {
     DIDescriptor Element = TParams.getElement(i);
     if (Element.isTemplateTypeParameter())
       constructTemplateTypeParameterDIE(Buffer,
                                         DITemplateTypeParameter(Element));
bool DwarfUnit::applySubprogramDefinitionAttributes(DISubprogram SP,
   // Add function template parameters.
   addTemplateParams(SPDie, SP.getTemplateParams());
 
   // Add the linkage name if we have one and it isn't in the Decl.
   StringRef LinkageName = SP.getLinkageName();
   assert(((LinkageName.empty() || DeclLinkageName.empty()) ||
           LinkageName == DeclLinkageName) &&
          "decl has a linkage name and it is different");
-  if (!LinkageName.empty() && DeclLinkageName.empty())
-    addString(SPDie, dwarf::DW_AT_MIPS_linkage_name,
-              GlobalValue::getRealLinkageName(LinkageName));
+  if (DeclLinkageName.empty())
+    addLinkageName(SPDie, LinkageName);
 
   if (!DeclDie)
     return false;
 
   // Refer to the function declaration where all the other attributes will be
   // found.
   addDIEEntry(SPDie, dwarf::DW_AT_specification, *DeclDie);
   return true;

test/DebugInfo/2010-04-06-NestedFnDbgInfo.ll

 ; REQUIRES: object-emission
 
 ; RUN: %llc_dwarf -O0 -filetype=obj -o - < %s | llvm-dwarfdump -debug-dump=info - | FileCheck %s
 ; Radar 7833483
 ; Do not emit a separate out-of-line definition DIE for the function-local 'foo'
 ; function (member of the function local 'A' type)
 ; CHECK: DW_TAG_class_type
 ; CHECK: DW_TAG_class_type
 ; CHECK-NEXT: DW_AT_name {{.*}} "A"
 ; Check that the subprogram inside the class definition has low_pc, only
 ; attached to the definition.
 ; CHECK: [[FOO_INL:0x........]]: DW_TAG_subprogram
 ; CHECK-NOT: DW_TAG
 ; CHECK: DW_AT_low_pc
 ; CHECK-NOT: DW_TAG
-; CHECK: DW_AT_MIPS_linkage_name {{.*}} "_ZZN1B2fnEvEN1A3fooEv"
+; CHECK: DW_AT_linkage_name {{.*}} "_ZZN1B2fnEvEN1A3fooEv"
 ; And just double check that there's no out of line definition that references
 ; this subprogram.
 ; CHECK-NOT: DW_AT_specification {{.*}} {[[FOO_INL]]}
 
 %class.A = type { i8 }
 %class.B = type { i8 }
 
 define i32 @main() ssp {

test/DebugInfo/PR20038.ll

 ; CHECK:   DW_AT_name {{.*}} "C"
 ; CHECK-NOT: {{DW_TAG|NULL}}
 ; CHECK:   DW_TAG_subprogram
 ; CHECK-NOT: DW_TAG
 ; CHECK:     DW_AT_name {{.*}} "~C"
 
 ; CHECK:  DW_TAG_subprogram
 ; CHECK-NOT: DW_TAG
-; CHECK:   DW_AT_MIPS_linkage_name {{.*}} "_ZN1CD1Ev"
+; CHECK:   DW_AT_linkage_name {{.*}} "_ZN1CD1Ev"
 ; CHECK-NOT: {{DW_TAG|NULL}}
 ; CHECK:  DW_TAG_formal_parameter
 ; CHECK-NOT: DW_TAG
 ; CHECK:     DW_AT_name {{.*}} "this"
 
 ; CHECK: DW_TAG_subprogram
 ; CHECK-NOT: DW_TAG
 ; CHECK:   DW_AT_name {{.*}} "fun4"

test/DebugInfo/X86/DW_AT_specification.ll

 ; RUN: llc -mtriple=x86_64-apple-darwin %s -o %t -filetype=obj
 ; RUN: llvm-dwarfdump -debug-dump=info %t | FileCheck %s
 
 ; test that the DW_AT_specification is a back edge in the file.
 
 ; CHECK: DW_TAG_subprogram
-; CHECK-NEXT: DW_AT_MIPS_linkage_name {{.*}} "_ZN3foo3barEv"
+; CHECK-NEXT: DW_AT_linkage_name {{.*}} "_ZN3foo3barEv"
 ; CHECK: DW_TAG_subprogram
 ; CHECK-NOT: DW_TAG
 ; CHECK: DW_AT_specification {{.*}} "_ZN3foo3barEv"
 
 
 @_ZZN3foo3barEvE1x = constant i32 0, align 4
 
 define void @_ZN3foo3barEv()  {

test/DebugInfo/X86/arguments.ll

 ;
 ; void func(foo f, foo g) {
 ;   f.i++;
 ; }
 
 ; CHECK: debug_info contents
 ; CHECK: DW_TAG_subprogram
 ; CHECK-NOT: DW_TAG
-; CHECK: DW_AT_MIPS_linkage_name{{.*}}"_Z4func3fooS_"
+; CHECK: DW_AT_linkage_name{{.*}}"_Z4func3fooS_"
 ; CHECK-NOT: NULL
 ; CHECK: DW_TAG_formal_parameter
 ; CHECK-NOT: DW_TAG
 ; CHECK: DW_AT_name{{.*}}"f"
 ; CHECK-NOT: NULL
 ; CHECK: DW_TAG_formal_parameter
 ; CHECK-NOT: DW_TAG
 ; CHECK: DW_AT_name{{.*}}"g"

test/DebugInfo/X86/concrete_out_of_line.ll

 ; RUN: llc -mtriple=x86_64-linux < %s -filetype=obj | llvm-dwarfdump -debug-dump=info - | FileCheck %s
 
 ; test that we add DW_AT_inline even when we only have concrete out of line
 ; instances.
 
 ; first check that we have a TAG_subprogram at a given offset and it has
 ; AT_inline.
 
 ; CHECK: DW_TAG_class_type
 ; CHECK:   DW_TAG_subprogram
 ; CHECK:   DW_TAG_subprogram
-; CHECK:     DW_AT_MIPS_linkage_name {{.*}} "_ZN12nsAutoRefCntaSEi"
+; CHECK:     DW_AT_linkage_name {{.*}} "_ZN12nsAutoRefCntaSEi"
 
 ; CHECK: DW_TAG_class_type
 ; CHECK:   DW_TAG_subprogram
-; CHECK:     DW_AT_MIPS_linkage_name {{.*}} "_ZN17nsAutoRefCnt7ReleaseEv"
+; CHECK:     DW_AT_linkage_name {{.*}} "_ZN17nsAutoRefCnt7ReleaseEv"
 ; CHECK:   DW_TAG_subprogram
 ; CHECK:     DW_AT_name {{.*}} "~nsAutoRefCnt"
 
 ; CHECK: DW_TAG_subprogram
 ; CHECK-NEXT:     DW_AT_{{.*}}linkage_name {{.*}}D2
 ; CHECK-NEXT:     DW_AT_specification {{.*}} "~nsAutoRefCnt"
 ; CHECK-NEXT:     DW_AT_inline
 ; CHECK-NOT:      DW_AT

test/DebugInfo/X86/debug-info-static-member.ll

 !27 = !MDGlobalVariable(name: "b", linkageName: "_ZN1C1bE", line: 15, isLocal: false, isDefinition: true, scope: null, file: !6, type: !9, variable: i32* @_ZN1C1bE, declaration: !19)
 !28 = !MDGlobalVariable(name: "c", linkageName: "_ZN1C1cE", line: 16, isLocal: false, isDefinition: true, scope: null, file: !6, type: !9, variable: i32* @_ZN1C1cE, declaration: !23)
 !29 = !MDLocalVariable(tag: DW_TAG_auto_variable, name: "instance_C", line: 20, scope: !5, file: !6, type: !13)
 !30 = !MDLocation(line: 20, scope: !5)
 !31 = !MDLocation(line: 21, scope: !5)
 !32 = !MDLocation(line: 22, scope: !5)
 !33 = !MDFile(filename: "/usr/local/google/home/blaikie/Development/llvm/src/tools/clang/test/CodeGenCXX/debug-info-static-member.cpp", directory: "/home/blaikie/local/Development/llvm/build/clang/x86-64/Debug/llvm")
 ; PRESENT verifies that static member declarations have these attributes:
-; external, declaration, accessibility, and either DW_AT_MIPS_linkage_name
+; external, declaration, accessibility, and either DW_AT_linkage_name
 ; (for variables) or DW_AT_const_value (for constants).
 ;
 ; PRESENT:      .debug_info contents:
 ; PRESENT:      DW_TAG_variable
 ; PRESENT-NEXT: DW_AT_specification {{.*}} "a"
 ; PRESENT-NEXT: DW_AT_location
 ; PRESENT-NEXT: DW_AT_linkage_name {{.*}} "_ZN1C1aE"
 ; PRESENT:      DW_TAG_class_type

test/DebugInfo/X86/debug-loc-offset.ll

 ; CHECK: DW_AT_high_pc
 
 ; CHECK: DW_TAG_compile_unit
 ; CHECK: DW_AT_low_pc
 ; CHECK: DW_AT_high_pc
 
 ; CHECK: DW_TAG_subprogram
 ; CHECK-NOT: DW_TAG
-; CHECK: DW_AT_MIPS_linkage_name [DW_FORM_strp]{{.*}}"_Z3baz1A"
+; CHECK: DW_AT_linkage_name [DW_FORM_strp]{{.*}}"_Z3baz1A"
 ; CHECK-NOT: {{DW_TAG|NULL}}
 ; CHECK: DW_TAG_formal_parameter
 ; CHECK-NOT: DW_TAG
 ; CHECK: DW_AT_location [DW_FORM_sec_offset]   (0x00000000)
 ; CHECK-NOT: DW_TAG
 ; CHECK: DW_AT_name [DW_FORM_strp]{{.*}}"a"
 
 ; CHECK: DW_TAG_variable

test/DebugInfo/X86/gnu-public-names.ll

 
 ; CHECK: [[C:0x[0-9a-f]+]]: DW_TAG_structure_type
 ; CHECK-NEXT: DW_AT_name {{.*}} "C"
 
 ; CHECK: DW_TAG_member
 ; CHECK-NEXT: DW_AT_name {{.*}} "static_member_variable"
 
 ; CHECK: DW_TAG_subprogram
-; CHECK-NEXT: DW_AT_MIPS_linkage_name
+; CHECK-NEXT: DW_AT_linkage_name
 ; CHECK-NEXT: DW_AT_name {{.*}} "member_function"
 
 ; CHECK: DW_TAG_subprogram
-; CHECK-NEXT: DW_AT_MIPS_linkage_name
+; CHECK-NEXT: DW_AT_linkage_name
 ; CHECK-NEXT: DW_AT_name {{.*}} "static_member_function"
 
 ; CHECK: [[INT:0x[0-9a-f]+]]: DW_TAG_base_type
 ; CHECK-NEXT: DW_AT_name {{.*}} "int"
 
 ; CHECK: [[GLOB_VAR:0x[0-9a-f]+]]: DW_TAG_variable
 ; CHECK-NEXT: DW_AT_name {{.*}} "global_variable"
 

 ; CHECK: DW_AT_location
 ; CHECK-NOT: DW_AT_specification
 
 ; CHECK: [[D:0x[0-9a-f]+]]: DW_TAG_structure_type
 ; CHECK-NEXT: DW_AT_name {{.*}} "D"
 
 ; CHECK: [[GLOB_NS_FUNC:0x[0-9a-f]+]]: DW_TAG_subprogram
 ; CHECK-NOT: DW_TAG
-; CHECK: DW_AT_MIPS_linkage_name
+; CHECK: DW_AT_linkage_name
 ; CHECK-NOT: DW_TAG
 ; CHECK: DW_AT_name {{.*}} "global_namespace_function"
 
 ; CHECK: DW_TAG_subprogram
 ; CHECK-NOT: DW_TAG
 ; CHECK:   DW_AT_name {{.*}} "f3"
 ; CHECK-NOT: {{DW_TAG|NULL}}
 ; CHECK: [[F3_Z:.*]]:   DW_TAG_variable

 ; CHECK: DW_AT_specification {{.*}} "_ZN1C15member_functionEv"
 
 ; CHECK: [[STATIC_MEM_FUNC:0x[0-9a-f]+]]: DW_TAG_subprogram
 ; CHECK-NOT: DW_TAG
 ; CHECK: DW_AT_specification {{.*}} "_ZN1C22static_member_functionEv"
 
 ; CHECK: [[GLOBAL_FUNC:0x[0-9a-f]+]]: DW_TAG_subprogram
 ; CHECK-NOT: DW_TAG
-; CHECK: DW_AT_MIPS_linkage_name
+; CHECK: DW_AT_linkage_name
 ; CHECK-NOT: DW_TAG
 ; CHECK: DW_AT_name {{.*}} "global_function"
 
 ; CHECK-LABEL: .debug_gnu_pubnames contents:
 ; CHECK-NEXT: length = {{.*}} version = 0x0002 unit_offset = 0x00000000 unit_size = {{.*}}
 ; CHECK-NEXT: Offset     Linkage  Kind     Name
 ; CHECK-DAG:  [[GLOBAL_FUNC]] EXTERNAL FUNCTION "global_function"
 ; CHECK-DAG:  [[NS]] EXTERNAL TYPE     "ns"

test/DebugInfo/X86/linkage-name.ll

 ; RUN: llc -mtriple=x86_64-macosx %s -o %t -filetype=obj
 ; RUN: llvm-dwarfdump -debug-dump=info %t | FileCheck %s
 
 ; CHECK: DW_TAG_subprogram [9] *
-; CHECK-NOT: DW_AT_MIPS_linkage_name
+; CHECK-NOT: DW_AT_{{(MIPS_)?}}linkage_name
 ; CHECK: DW_AT_specification
 
 %class.A = type { i8 }
 
 @a = global %class.A zeroinitializer, align 1
 
 define i32 @_ZN1A1aEi(%class.A* %this, i32 %b) nounwind uwtable ssp align 2 {
 entry:

test/DebugInfo/X86/pr11300.ll

 ; RUN: llc -mtriple=x86_64-apple-darwin %s -o %t -filetype=obj
 ; RUN: llvm-dwarfdump -debug-dump=info %t | FileCheck %s
 
 ; test that the DW_AT_specification is a back edge in the file.
 
 ; Skip the definition of zed(foo*)
 ; CHECK: DW_TAG_subprogram
 ; CHECK: DW_TAG_class_type
 ; CHECK:   DW_TAG_subprogram
-; CHECK:     DW_AT_MIPS_linkage_name {{.*}} "_ZN3foo3barEv"
+; CHECK:     DW_AT_linkage_name {{.*}} "_ZN3foo3barEv"
 ; CHECK: DW_TAG_subprogram
 ; CHECK-NOT: DW_TAG
 ; CHECK:   DW_AT_specification {{.*}} "_ZN3foo3barEv"
 
 %struct.foo = type { i8 }
 
 define void @_Z3zedP3foo(%struct.foo* %x) uwtable {
 entry:

test/DebugInfo/namespace_function_definition.ll

 ; REQUIRES: object-emission
 
 ; RUN: %llc_dwarf -O0 -filetype=obj < %s | llvm-dwarfdump -debug-dump=info - | FileCheck %s
 
 ; Generated from clang with the following source:
 ; namespace ns {
 ; void func() {
 ; }
 ; }
 
 ; CHECK: DW_TAG_namespace
 ; CHECK-NEXT: DW_AT_name {{.*}} "ns"
 ; CHECK: DW_TAG_subprogram
 ; CHECK-NOT: DW_TAG
 ; CHECK:   DW_AT_low_pc
 ; CHECK-NOT: DW_TAG
-; CHECK:   DW_AT_MIPS_linkage_name {{.*}} "_ZN2ns4funcEv"
+; CHECK:   DW_AT_linkage_name {{.*}} "_ZN2ns4funcEv"
 ; CHECK: NULL
 ; CHECK: NULL
 
 ; Function Attrs: nounwind uwtable
 define void @_ZN2ns4funcEv() #0 {
 entry:
   ret void, !dbg !11
 }

test/DebugInfo/namespace_inline_function_definition.ll

 ; int main() { return ns::func(x); }
 ; int __attribute__((always_inline)) ns::func(int i) { return i * 2; }
 
 ; CHECK: DW_TAG_namespace
 ; CHECK-NEXT: DW_AT_name {{.*}} "ns"
 ; CHECK-NOT: DW_TAG
 ; CHECK:   DW_TAG_subprogram
 ; CHECK-NOT: DW_TAG
-; CHECK:   DW_AT_MIPS_linkage_name {{.*}} "_ZN2ns4funcEi"
+; CHECK:   DW_AT_linkage_name {{.*}} "_ZN2ns4funcEi"
 ; CHECK-NOT: DW_TAG
 ; CHECK:   DW_TAG_formal_parameter
 ; CHECK:   NULL
 ; CHECK-NOT: NULL
 ; CHECK:   DW_TAG_subprogram
 ; CHECK-NOT: DW_TAG
 ; CHECK:     DW_AT_abstract_origin {{.*}} "_ZN2ns4funcEi"
 ; CHECK-NOT: DW_TAG

test/Linker/type-unique-odr-a.ll

 ; CHECK:      DW_TAG_class_type
 ; CHECK-NEXT:   DW_AT_name {{.*}} "A"
 ; CHECK-NOT:  DW_TAG
 ; CHECK:      DW_TAG_member
 ; CHECK-NEXT:   DW_AT_name {{.*}} "data"
 ; CHECK-NOT:  DW_TAG
 ; CHECK:      DW_TAG_subprogram
 ; CHECK-NOT: DW_TAG
-; CHECK:   DW_AT_MIPS_linkage_name {{.*}} "_ZN1A6getFooEv"
+; CHECK:   DW_AT_linkage_name {{.*}} "_ZN1A6getFooEv"
 ; CHECK-NOT: DW_TAG
 ; CHECK:   DW_AT_name {{.*}} "getFoo"
 ; CHECK:      DW_TAG_subprogram
 ; CHECK-NOT: DW_TAG
-; CHECK:   DW_AT_MIPS_linkage_name {{.*}} "_Z3bazv"
+; CHECK:   DW_AT_linkage_name {{.*}} "_Z3bazv"
 ; CHECK:      DW_TAG_subprogram
 ; CHECK-NOT: DW_TAG
-; CHECK:   DW_AT_MIPS_linkage_name {{.*}} "_ZL3barv"
+; CHECK:   DW_AT_linkage_name {{.*}} "_ZL3barv"
 
 ; getFoo and A may only appear once.
 ; CHECK-NOT:  AT_name{{.*(getFoo)|("A")}}
 
 
 ; ModuleID = 'type-unique-odr-a.cpp'
 
 %class.A = type { i32 }