Debug Info: for static member variables, always put AT_MIPS_linkage_name to the

definition DIE (TAG_variable), and put AT_MIPS_linkage_name to TAG_member when
DarwinGDBCompat is true.

Darwin GDB needs AT_MIPS_linkage_name at both places to work.

Follow-up patch to r176143.
rdar://problem/13291234


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176220 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 97 insertions, 8 deletions

diff --git a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
index 59e433b70b..00b91e70c7 100644
--- a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -1349,12 +1349,19 @@ void CompileUnit::createGlobalVariableDIE(const MDNode *N) {
     // Add linkage name.
     StringRef LinkageName = GV.getLinkageName();
     if (!LinkageName.empty() && isGlobalVariable) {
-      addString(VariableDIE, dwarf::DW_AT_MIPS_linkage_name,
+      // From dwarf-4: DIE to which DW_AT_linkage_name may apply include:
+      // TAG_commono_block, TAG_constant, TAG_entry_point, TAG_subporgram and
+      // TAG_variable. For static member variables, gcc 4.7 puts
+      // MIPS_linkage_name on the definition DIE only, but Darwin gdb needs
+      // MIPS_linkage_name at both places.
+      // Per discussion with Eric, for static member variables, we put
+      // MIPS_linkage_name on the definition DIE (TAG_variable) and conditionaly
+      // put MIPS_linkage_name on TAG_member when DarwinGDBCompat is on.
+      addString(IsStaticMember && VariableSpecDIE ?
+                VariableSpecDIE : 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,
+      if (IsStaticMember && VariableSpecDIE && DD->useDarwinGDBCompat())
+        addString(VariableDIE, dwarf::DW_AT_MIPS_linkage_name,
                   getRealLinkageName(LinkageName));
     }
   } else if (const ConstantInt *CI =
diff --git a/test/DebugInfo/X86/debug-info-static-member.ll b/test/DebugInfo/X86/debug-info-static-member.ll
index 228507956a..c03d19addd 100644
--- a/test/DebugInfo/X86/debug-info-static-member.ll
+++ b/test/DebugInfo/X86/debug-info-static-member.ll
@@ -1,6 +1,9 @@
 ; RUN: llc %s -o %t -filetype=obj -O0 -mtriple=x86_64-unknown-linux-gnu
 ; RUN: llvm-dwarfdump -debug-dump=info %t | FileCheck %s -check-prefix=PRESENT
 ; RUN: llvm-dwarfdump -debug-dump=info %t | FileCheck %s -check-prefix=ABSENT
+; RUN: llc %s -o %t -filetype=obj -O0 -mtriple=x86_64-apple-darwin
+; RUN: llvm-dwarfdump -debug-dump=info %t | FileCheck %s -check-prefix=DARWINP
+; RUN: llvm-dwarfdump -debug-dump=info %t | FileCheck %s -check-prefix=DARWINA
 ; Verify that attributes we do want are PRESENT;
 ; verify that attributes we don't want are ABSENT.
 ; It's a lot easier to do this in two passes than in one.
@@ -97,7 +100,6 @@ declare void @llvm.dbg.declare(metadata, metadata) nounwind readnone
 ; PRESENT:      DW_AT_external
 ; PRESENT:      DW_AT_declaration
 ; PRESENT:      DW_AT_accessibility [DW_FORM_data1]   (0x03)
-; PRESENT:      DW_AT_MIPS_linkage_name {{.*}} "_ZN1C1aE"
 ; PRESENT:      DW_TAG_member
 ; PRESENT-NEXT: DW_AT_name {{.*}} "const_a"
 ; PRESENT:      DW_AT_external
@@ -107,7 +109,6 @@ declare void @llvm.dbg.declare(metadata, metadata) nounwind readnone
 ; PRESENT:      0x[[DECL_B:[0-9a-f]+]]: DW_TAG_member
 ; PRESENT-NEXT: DW_AT_name {{.*}} "b"
 ; PRESENT:      DW_AT_accessibility [DW_FORM_data1]   (0x02)
-; PRESENT:      DW_AT_MIPS_linkage_name {{.*}} "_ZN1C1bE"
 ; PRESENT:      DW_TAG_member
 ; PRESENT-NEXT: DW_AT_name {{.*}} "const_b"
 ; PRESENT:      DW_AT_accessibility [DW_FORM_data1]   (0x02)
@@ -115,7 +116,6 @@ declare void @llvm.dbg.declare(metadata, metadata) nounwind readnone
 ; PRESENT:      0x[[DECL_C:[0-9a-f]+]]: DW_TAG_member
 ; PRESENT-NEXT: DW_AT_name {{.*}} "c"
 ; PRESENT:      DW_AT_accessibility [DW_FORM_data1]   (0x01)
-; PRESENT:      DW_AT_MIPS_linkage_name {{.*}} "_ZN1C1cE"
 ; PRESENT:      DW_TAG_member
 ; PRESENT-NEXT: DW_AT_name {{.*}} "const_c"
 ; PRESENT:      DW_AT_accessibility [DW_FORM_data1]   (0x01)
@@ -141,6 +141,59 @@ declare void @llvm.dbg.declare(metadata, metadata) nounwind readnone
 ; PRESENT-NEXT: DW_AT_location
 ; PRESENT-NEXT: DW_AT_MIPS_linkage_name {{.*}} "_ZN1C1cE"
 
+; For Darwin gdb:
+; DARWINP:      .debug_info contents:
+; DARWINP:      DW_TAG_class_type
+; DARWINP-NEXT: DW_AT_name {{.*}} "C"
+; DARWINP:      0x[[DECL_A:[0-9a-f]+]]: DW_TAG_member
+; DARWINP-NEXT: DW_AT_name {{.*}} "a"
+; DARWINP:      DW_AT_external
+; DARWINP:      DW_AT_declaration
+; DARWINP:      DW_AT_accessibility [DW_FORM_data1]   (0x03)
+; DARWINP:      DW_AT_MIPS_linkage_name {{.*}} "_ZN1C1aE"
+; DARWINP:      DW_TAG_member
+; DARWINP-NEXT: DW_AT_name {{.*}} "const_a"
+; DARWINP:      DW_AT_external
+; DARWINP:      DW_AT_declaration
+; DARWINP:      DW_AT_accessibility [DW_FORM_data1]   (0x03)
+; DARWINP:      DW_AT_const_value {{.*}} (1)
+; DARWINP:      0x[[DECL_B:[0-9a-f]+]]: DW_TAG_member
+; DARWINP-NEXT: DW_AT_name {{.*}} "b"
+; DARWINP:      DW_AT_accessibility [DW_FORM_data1]   (0x02)
+; DARWINP:      DW_AT_MIPS_linkage_name {{.*}} "_ZN1C1bE"
+; DARWINP:      DW_TAG_member
+; DARWINP-NEXT: DW_AT_name {{.*}} "const_b"
+; DARWINP:      DW_AT_accessibility [DW_FORM_data1]   (0x02)
+; DARWINP:      DW_AT_const_value {{.*}} (0x4048f5c3)
+; DARWINP:      0x[[DECL_C:[0-9a-f]+]]: DW_TAG_member
+; DARWINP-NEXT: DW_AT_name {{.*}} "c"
+; DARWINP:      DW_AT_accessibility [DW_FORM_data1]   (0x01)
+; DARWINP:      DW_AT_MIPS_linkage_name {{.*}} "_ZN1C1cE"
+; DARWINP:      DW_TAG_member
+; DARWINP-NEXT: DW_AT_name {{.*}} "const_c"
+; DARWINP:      DW_AT_accessibility [DW_FORM_data1]   (0x01)
+; DARWINP:      DW_AT_const_value {{.*}} (0x00000012)
+; While we're here, a normal member has data_member_location and
+; accessibility attributes.
+; DARWINP:      DW_TAG_member
+; DARWINP-NEXT: DW_AT_name {{.*}} "d"
+; DARWINP:      DW_AT_data_member_location
+; DARWINP:      DW_AT_accessibility [DW_FORM_data1]   (0x01)
+; DARWINP:      NULL
+; Definitions point back to their declarations, and have a location.
+; DARWINP:      DW_TAG_variable
+; DARWINP-NEXT: DW_AT_specification {{.*}} {0x[[DECL_A]]}
+; DARWINP-NEXT: DW_AT_location
+; DARWINP-NEXT: DW_AT_MIPS_linkage_name {{.*}} "_ZN1C1aE"
+; DARWINP:      DW_TAG_variable
+; DARWINP-NEXT: DW_AT_specification {{.*}} {0x[[DECL_B]]}
+; DARWINP-NEXT: DW_AT_location
+; DARWINP-NEXT: DW_AT_MIPS_linkage_name {{.*}} "_ZN1C1bE"
+; DARWINP:      DW_TAG_variable
+; DARWINP-NEXT: DW_AT_specification {{.*}} {0x[[DECL_C]]}
+; DARWINP-NEXT: DW_AT_location
+; DARWINP-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
 ; have DW_AT_const_value and constants do not have DW_AT_MIPS_linkage_name.
@@ -172,3 +225,32 @@ declare void @llvm.dbg.declare(metadata, metadata) nounwind readnone
 ; ABSENT-NOT:  DW_AT_const_value
 ; ABSENT-NOT:  DW_AT_location
 ; ABSENT:      NULL
+
+; For Darwin gdb:
+; DARWINA:      .debug_info contents:
+; DARWINA:      DW_TAG_member
+; DARWINA:      DW_AT_name {{.*}} "a"
+; DARWINA-NOT:  DW_AT_const_value
+; DARWINA-NOT:  location
+; DARWINA:      DW_AT_name {{.*}} "const_a"
+; DARWINA-NOT:  DW_AT_MIPS_linkage_name
+; DARWINA-NOT:  location
+; DARWINA:      DW_AT_name {{.*}} "b"
+; DARWINA-NOT:  DW_AT_const_value
+; DARWINA-NOT:  location
+; DARWINA:      DW_AT_name {{.*}} "const_b"
+; DARWINA-NOT:  DW_AT_MIPS_linkage_name
+; DARWINA-NOT:  location
+; DARWINA:      DW_AT_name {{.*}} "c"
+; DARWINA-NOT:  DW_AT_const_value
+; DARWINA-NOT:  location
+; DARWINA:      DW_AT_name {{.*}} "const_c"
+; DARWINA-NOT:  DW_AT_MIPS_linkage_name
+; DARWINA-NOT:  location
+; While we're here, a normal member does not have a linkage name, constant
+; value, or DW_AT_location.
+; DARWINA:      DW_AT_name {{.*}} "d"
+; DARWINA-NOT:  DW_AT_MIPS_linkage_name
+; DARWINA-NOT:  DW_AT_const_value
+; DARWINA-NOT:  DW_AT_location
+; DARWINA:      NULL