Debug Info: for static member variables, add AT_MIPS_linkage_name to the
definition DIE, to make old GDB happy.

We have a regression for old GDB when Clang uses DW_TAG_member to declare
static members inside a class, instead of DW_TAG_variable. This patch will fix
this regression.

rdar://problem/13291234


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176143 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
index 93b00fb..59e433b 100644
--- a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -1348,9 +1348,15 @@
     }
     // Add linkage name.
     StringRef LinkageName = GV.getLinkageName();
-    if (!LinkageName.empty() && isGlobalVariable)
+    if (!LinkageName.empty() && isGlobalVariable) {
       addString(VariableDIE, dwarf::DW_AT_MIPS_linkage_name,
                 getRealLinkageName(LinkageName));
+      // To make old GDB happy, for static member variables, we add
+      // AT_MIPS_linkage_name to the definition DIE as well.
+      if (IsStaticMember && VariableSpecDIE)
+        addString(VariableSpecDIE, dwarf::DW_AT_MIPS_linkage_name,
+                  getRealLinkageName(LinkageName));
+    }
   } else if (const ConstantInt *CI =
              dyn_cast_or_null<ConstantInt>(GV.getConstant())) {
     // AT_const_value was added when the static memeber was created. To avoid
diff --git a/test/DebugInfo/X86/debug-info-static-member.ll b/test/DebugInfo/X86/debug-info-static-member.ll
index d7a6578..2285079 100644
--- a/test/DebugInfo/X86/debug-info-static-member.ll
+++ b/test/DebugInfo/X86/debug-info-static-member.ll
@@ -131,12 +131,15 @@
 ; PRESENT:      DW_TAG_variable
 ; PRESENT-NEXT: DW_AT_specification {{.*}} {0x[[DECL_A]]}
 ; PRESENT-NEXT: DW_AT_location
+; PRESENT-NEXT: DW_AT_MIPS_linkage_name {{.*}} "_ZN1C1aE"
 ; PRESENT:      DW_TAG_variable
 ; PRESENT-NEXT: DW_AT_specification {{.*}} {0x[[DECL_B]]}
 ; PRESENT-NEXT: DW_AT_location
+; PRESENT-NEXT: DW_AT_MIPS_linkage_name {{.*}} "_ZN1C1bE"
 ; PRESENT:      DW_TAG_variable
 ; PRESENT-NEXT: DW_AT_specification {{.*}} {0x[[DECL_C]]}
 ; PRESENT-NEXT: DW_AT_location
+; PRESENT-NEXT: DW_AT_MIPS_linkage_name {{.*}} "_ZN1C1cE"
 
 ; ABSENT verifies that static member declarations do not have either
 ; DW_AT_location or DW_AT_data_member_location; also, variables do not