12 files changed, 112 insertions, 27 deletions
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
index 0daca72b30d..ff70f6ca044 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -185,7 +185,8 @@ DIE *DwarfCompileUnit::getOrCreateGlobalVariableDIE(
     }
 
     addBlock(*VariableDIE, dwarf::DW_AT_location, Loc);
-    addLinkageName(*VariableDIE, GV->getLinkageName());
+    if (DD->useAllLinkageNames())
+      addLinkageName(*VariableDIE, GV->getLinkageName());
   } else if (const ConstantInt *CI =
                  dyn_cast_or_null<ConstantInt>(GV->getVariable())) {
     addConstantValue(*VariableDIE, CI, GTy);
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 36b87657ae7..373b7e7daa3 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -105,13 +105,21 @@ DwarfPubSections("generate-dwarf-pub-sections", cl::Hidden,
                             clEnumVal(Disable, "Disabled"), clEnumValEnd),
                  cl::init(Default));
 
-static cl::opt<DefaultOnOff>
-DwarfLinkageNames("dwarf-linkage-names", cl::Hidden,
-                  cl::desc("Emit DWARF linkage-name attributes."),
-                  cl::values(clEnumVal(Default, "Default for platform"),
-                             clEnumVal(Enable, "Enabled"),
-                             clEnumVal(Disable, "Disabled"), clEnumValEnd),
-                  cl::init(Default));
+enum LinkageNameOption {
+  DefaultLinkageNames,
+  AllLinkageNames,
+  AbstractLinkageNames
+};
+static cl::opt<LinkageNameOption>
+    DwarfLinkageNames("dwarf-linkage-names", cl::Hidden,
+                      cl::desc("Which DWARF linkage-name attributes to emit."),
+                      cl::values(clEnumValN(DefaultLinkageNames, "Default",
+                                            "Default for platform"),
+                                 clEnumValN(AllLinkageNames, "All", "All"),
+                                 clEnumValN(AbstractLinkageNames, "Abstract",
+                                            "Abstract subprograms"),
+                                 clEnumValEnd),
+                      cl::init(DefaultLinkageNames));
 
 static const char *const DWARFGroupName = "DWARF Emission";
 static const char *const DbgTimerName = "DWARF Debug Writer";
@@ -245,11 +253,11 @@ DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
   else
     HasDwarfPubSections = DwarfPubSections == Enable;
 
-  // SCE does not use linkage names.
-  if (DwarfLinkageNames == Default)
-    UseLinkageNames = !tuneForSCE();
+  // SCE defaults to linkage names only for abstract subprograms.
+  if (DwarfLinkageNames == DefaultLinkageNames)
+    UseAllLinkageNames = !tuneForSCE();
   else
-    UseLinkageNames = DwarfLinkageNames == Enable;
+    UseAllLinkageNames = DwarfLinkageNames == AllLinkageNames;
 
   unsigned DwarfVersionNumber = Asm->TM.Options.MCOptions.DwarfVersion;
   DwarfVersion = DwarfVersionNumber ? DwarfVersionNumber
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
index c5861497f64..ad0241cb99b 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -249,8 +249,8 @@ class DwarfDebug : public DebugHandlerBase {
   /// Whether to use the GNU TLS opcode (instead of the standard opcode).
   bool UseGNUTLSOpcode;
 
-  /// Whether to emit DW_AT_[MIPS_]linkage_name.
-  bool UseLinkageNames;
+  /// Whether to emit all linkage names, or just abstract subprograms.
+  bool UseAllLinkageNames;
 
   /// Version of dwarf we're emitting.
   unsigned DwarfVersion;
@@ -478,8 +478,9 @@ public:
     SymSize[Sym] = Size;
   }
 
-  /// Returns whether to emit DW_AT_[MIPS_]linkage_name.
-  bool useLinkageNames() const { return UseLinkageNames; }
+  /// Returns whether we should emit all DW_AT_[MIPS_]linkage_name.
+  /// If not, we still might emit certain cases.
+  bool useAllLinkageNames() const { return UseAllLinkageNames; }
 
   /// Returns whether to use DW_OP_GNU_push_tls_address, instead of the
   /// standard DW_OP_form_tls_address opcode
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
index 387921cb46f..9003af528d0 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
@@ -665,7 +665,7 @@ void DwarfUnit::addConstantValue(DIE &Die, const APInt &Val, bool Unsigned) {
 }
 
 void DwarfUnit::addLinkageName(DIE &Die, StringRef LinkageName) {
-  if (!LinkageName.empty() && DD->useLinkageNames())
+  if (!LinkageName.empty())
     addString(Die,
               DD->getDwarfVersion() >= 4 ? dwarf::DW_AT_linkage_name
                                          : dwarf::DW_AT_MIPS_linkage_name,
@@ -1169,7 +1169,9 @@ bool DwarfUnit::applySubprogramDefinitionAttributes(const DISubprogram *SP,
   assert(((LinkageName.empty() || DeclLinkageName.empty()) ||
           LinkageName == DeclLinkageName) &&
          "decl has a linkage name and it is different");
-  if (DeclLinkageName.empty())
+  if (DeclLinkageName.empty() &&
+      // Always emit it for abstract subprograms.
+      (DD->useAllLinkageNames() || DU->getAbstractSPDies().lookup(SP)))
     addLinkageName(SPDie, LinkageName);
 
   if (!DeclDie)
diff --git a/llvm/test/DebugInfo/Generic/PR20038.ll b/llvm/test/DebugInfo/Generic/PR20038.ll
index aebcc708caf..f9e0940aa47 100644
--- a/llvm/test/DebugInfo/Generic/PR20038.ll
+++ b/llvm/test/DebugInfo/Generic/PR20038.ll
@@ -3,7 +3,7 @@
 ; For some reason, the output when targetting sparc is not quite as expected.
 ; XFAIL: sparc
 
-; RUN: %llc_dwarf -O0 -filetype=obj -dwarf-linkage-names=Enable < %s | llvm-dwarfdump -debug-dump=info - | FileCheck %s
+; RUN: %llc_dwarf -O0 -filetype=obj -dwarf-linkage-names=All < %s | llvm-dwarfdump -debug-dump=info - | FileCheck %s
 
 ; IR generated from clang -O0 with:
 ; struct C {
diff --git a/llvm/test/DebugInfo/Generic/cross-cu-inlining.ll b/llvm/test/DebugInfo/Generic/cross-cu-inlining.ll
index 748f86fdd58..5dea31f7705 100644
--- a/llvm/test/DebugInfo/Generic/cross-cu-inlining.ll
+++ b/llvm/test/DebugInfo/Generic/cross-cu-inlining.ll
@@ -1,7 +1,7 @@
 ; REQUIRES: object-emission
 
-; RUN: %llc_dwarf -O0 -filetype=obj -dwarf-linkage-names=Enable < %s | llvm-dwarfdump -debug-dump=info - | FileCheck -implicit-check-not=DW_TAG %s
-; RUN: %llc_dwarf -dwarf-accel-tables=Enable -dwarf-linkage-names=Enable -O0 -filetype=obj < %s | llvm-dwarfdump - | FileCheck --check-prefix=CHECK-ACCEL --check-prefix=CHECK %s
+; RUN: %llc_dwarf -O0 -filetype=obj -dwarf-linkage-names=All < %s | llvm-dwarfdump -debug-dump=info - | FileCheck -implicit-check-not=DW_TAG %s
+; RUN: %llc_dwarf -dwarf-accel-tables=Enable -dwarf-linkage-names=All -O0 -filetype=obj < %s | llvm-dwarfdump - | FileCheck --check-prefix=CHECK-ACCEL --check-prefix=CHECK %s
 
 ; Build from source:
 ; $ clang++ a.cpp b.cpp -g -c -emit-llvm
diff --git a/llvm/test/DebugInfo/Generic/enum-types.ll b/llvm/test/DebugInfo/Generic/enum-types.ll
index e63ac3bc5f6..4e49dc37522 100644
--- a/llvm/test/DebugInfo/Generic/enum-types.ll
+++ b/llvm/test/DebugInfo/Generic/enum-types.ll
@@ -1,6 +1,6 @@
 ; REQUIRES: object-emission
 ;
-; RUN: %llc_dwarf -filetype=obj -O0 -dwarf-linkage-names=Enable < %s | llvm-dwarfdump -debug-dump=info - | FileCheck %s
+; RUN: %llc_dwarf -filetype=obj -O0 -dwarf-linkage-names=All < %s | llvm-dwarfdump -debug-dump=info - | FileCheck %s
 
 ; Make sure we can handle enums with the same identifier but in enum types of
 ; different compile units.
diff --git a/llvm/test/DebugInfo/Generic/linkage-name-abstract.ll b/llvm/test/DebugInfo/Generic/linkage-name-abstract.ll
new file mode 100644
index 00000000000..c2e6a28e388
--- /dev/null
+++ b/llvm/test/DebugInfo/Generic/linkage-name-abstract.ll
@@ -0,0 +1,73 @@
+; RUN: %llc_dwarf -O0 -filetype=obj -dwarf-linkage-names=Abstract < %s | llvm-dwarfdump -debug-dump=info - > %t
+; RUN: FileCheck %s -check-prefix=ONENAME < %t
+; RUN: FileCheck %s -check-prefix=REF < %t 
+; Verify tuning for SCE gets us Abstract only.
+; RUN: %llc_dwarf -O0 -filetype=obj -debugger-tune=sce < %s | llvm-dwarfdump -debug-dump=info - > %t
+; RUN: FileCheck %s -check-prefix=ONENAME < %t
+; RUN: FileCheck %s -check-prefix=REF < %t 
+; REQUIRES: object-emission
+
+; Verify that the only linkage-name present is the abstract origin of the
+; inlined subprogram.
+
+; IR generated from clang -O0 with:
+; void f1();
+; __attribute__((always_inline)) void f2() { 
+;   f1();
+; }
+; void f3() {
+;   f2();
+; }
+
+; Show that there's only one linkage_name.
+; ONENAME:     {{DW_AT(_MIPS)?_linkage_name}}
+; ONENAME-NOT: {{DW_AT(_MIPS)?_linkage_name}}
+
+; Locate the subprogram DIE with the linkage name.
+; Show that the inlined_subroutine refers to it.
+; REF:     DW_TAG_subprogram
+; REF:     [[FOO:0x.*]]: DW_TAG_subprogram
+; REF-NOT: {{DW_TAG|NULL}}
+; REF:     {{DW_AT(_MIPS)?_linkage_name}}
+; REF:     DW_TAG_inlined_subroutine
+; REF-NOT: {{DW_TAG|NULL}}
+; REF:     DW_AT_abstract_origin {{.*}} {[[FOO]]}
+
+; Function Attrs: alwaysinline uwtable
+define void @_Z2f2v() #0 !dbg !4 {
+entry:
+  call void @_Z2f1v(), !dbg !11
+  ret void, !dbg !12
+}
+
+declare void @_Z2f1v()
+
+; Function Attrs: uwtable
+define void @_Z2f3v() #2 !dbg !7 {
+entry:
+  call void @_Z2f1v(), !dbg !13
+  ret void, !dbg !15
+}
+
+attributes #0 = { alwaysinline uwtable }
+attributes #2 = { uwtable }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!8, !9}
+!llvm.ident = !{!10}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 3.9.0 (trunk 265282)", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
+!1 = !DIFile(filename: "linkage-name-abstract.cpp", directory: "/home/probinson/projects/scratch")
+!2 = !{}
+!4 = distinct !DISubprogram(name: "f2", linkageName: "_Z2f2v", scope: !1, file: !1, line: 2, type: !5, isLocal: false, isDefinition: true, scopeLine: 2, flags: DIFlagPrototyped, isOptimized: false, unit: !0, variables: !2)
+!5 = !DISubroutineType(types: !6)
+!6 = !{null}
+!7 = distinct !DISubprogram(name: "f3", linkageName: "_Z2f3v", scope: !1, file: !1, line: 5, type: !5, isLocal: false, isDefinition: true, scopeLine: 5, flags: DIFlagPrototyped, isOptimized: false, unit: !0, variables: !2)
+!8 = !{i32 2, !"Dwarf Version", i32 4}
+!9 = !{i32 2, !"Debug Info Version", i32 3}
+!10 = !{!"clang version 3.9.0 (trunk 265282)"}
+!11 = !DILocation(line: 3, column: 3, scope: !4)
+!12 = !DILocation(line: 4, column: 1, scope: !4)
+!13 = !DILocation(line: 3, column: 3, scope: !4, inlinedAt: !14)
+!14 = distinct !DILocation(line: 6, column: 3, scope: !7)
+!15 = !DILocation(line: 7, column: 1, scope: !7)
diff --git a/llvm/test/DebugInfo/Generic/namespace.ll b/llvm/test/DebugInfo/Generic/namespace.ll
index a76191d2f4a..bf45144a54b 100644
--- a/llvm/test/DebugInfo/Generic/namespace.ll
+++ b/llvm/test/DebugInfo/Generic/namespace.ll
@@ -1,6 +1,6 @@
 ; REQUIRES: object-emission
 
-; RUN: %llc_dwarf -O0 -filetype=obj -dwarf-linkage-names=Enable < %s | llvm-dwarfdump - | FileCheck %s
+; RUN: %llc_dwarf -O0 -filetype=obj -dwarf-linkage-names=All < %s | llvm-dwarfdump - | FileCheck %s
 ; CHECK: debug_info contents
 ; CHECK: [[NS1:0x[0-9a-f]*]]:{{ *}}DW_TAG_namespace
 ; CHECK-NEXT: DW_AT_name{{.*}} = "A"
diff --git a/llvm/test/DebugInfo/Generic/namespace_function_definition.ll b/llvm/test/DebugInfo/Generic/namespace_function_definition.ll
index 283761314a4..04fcc3bfb90 100644
--- a/llvm/test/DebugInfo/Generic/namespace_function_definition.ll
+++ b/llvm/test/DebugInfo/Generic/namespace_function_definition.ll
@@ -1,6 +1,6 @@
 ; REQUIRES: object-emission
 
-; RUN: %llc_dwarf -O0 -filetype=obj -dwarf-linkage-names=Enable < %s | llvm-dwarfdump -debug-dump=info - | FileCheck %s
+; RUN: %llc_dwarf -O0 -filetype=obj -dwarf-linkage-names=All < %s | llvm-dwarfdump -debug-dump=info - | FileCheck %s
 
 ; Generated from clang with the following source:
 ; namespace ns {
diff --git a/llvm/test/DebugInfo/Generic/namespace_inline_function_definition.ll b/llvm/test/DebugInfo/Generic/namespace_inline_function_definition.ll
index 7b60a6bdb79..72502e5f759 100644
--- a/llvm/test/DebugInfo/Generic/namespace_inline_function_definition.ll
+++ b/llvm/test/DebugInfo/Generic/namespace_inline_function_definition.ll
@@ -1,6 +1,6 @@
 ; REQUIRES: object-emission
 
-; RUN: %llc_dwarf -O0 -filetype=obj -dwarf-linkage-names=Enable < %s | llvm-dwarfdump -debug-dump=info - | FileCheck %s
+; RUN: %llc_dwarf -O0 -filetype=obj -dwarf-linkage-names=All < %s | llvm-dwarfdump -debug-dump=info - | FileCheck %s
 
 ; Generate from clang with the following source. Note that the definition of
 ; the inline function follows its use to workaround another bug that should be
diff --git a/llvm/test/Linker/type-unique-odr-a.ll b/llvm/test/Linker/type-unique-odr-a.ll
index d7640ea761c..ed6c17c81c6 100644
--- a/llvm/test/Linker/type-unique-odr-a.ll
+++ b/llvm/test/Linker/type-unique-odr-a.ll
@@ -1,11 +1,11 @@
 ; REQUIRES: default_triple, object-emission
 ;
 ; RUN: llvm-link %s %p/type-unique-odr-b.ll -S -o - \
-; RUN:   | %llc_dwarf -dwarf-linkage-names=Enable -filetype=obj -O0 \
+; RUN:   | %llc_dwarf -dwarf-linkage-names=All -filetype=obj -O0 \
 ; RUN:   | llvm-dwarfdump -debug-dump=info - \
 ; RUN:   | FileCheck %s
 ; RUN: llvm-link %p/type-unique-odr-b.ll %s -S -o - \
-; RUN:   | %llc_dwarf -dwarf-linkage-names=Enable -filetype=obj -O0 \
+; RUN:   | %llc_dwarf -dwarf-linkage-names=All -filetype=obj -O0 \
 ; RUN:   | llvm-dwarfdump -debug-dump=info - \
 ; RUN:   | FileCheck %s
 ;