From 8938895a8338e6084eb12a2bb4bf044928436173 Mon Sep 17 00:00:00 2001
From: Eric Christopher <echristo@apple.com>
Date: Wed, 7 Mar 2012 00:15:19 +0000
Subject: [PATCH] Add the DW_AT_APPLE_runtime_class attribute to forward
 declarations as well as completely defined classes.

This fixes rdar://10956070

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152171 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp | 11 +++++----
 test/DebugInfo/objc-fwd-decl.ll             | 27 +++++++++++++++++++++
 2 files changed, 33 insertions(+), 5 deletions(-)
 create mode 100644 test/DebugInfo/objc-fwd-decl.ll

diff --git a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
index 51c635e268c..af99f6ba4da 100644
--- a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -870,11 +870,6 @@ void CompileUnit::constructTypeDIE(DIE &Buffer, DICompositeType CTy) {
     if (CTy.isAppleBlockExtension())
       addUInt(&Buffer, dwarf::DW_AT_APPLE_block, dwarf::DW_FORM_flag, 1);
 
-    unsigned RLang = CTy.getRunTimeLang();
-    if (RLang)
-      addUInt(&Buffer, dwarf::DW_AT_APPLE_runtime_class,
-              dwarf::DW_FORM_data1, RLang);
-
     DICompositeType ContainingType = CTy.getContainingType();
     if (DIDescriptor(ContainingType).isCompositeType())
       addDIEEntry(&Buffer, dwarf::DW_AT_containing_type, dwarf::DW_FORM_ref4,
@@ -922,6 +917,12 @@ void CompileUnit::constructTypeDIE(DIE &Buffer, DICompositeType CTy) {
     // Add source line info if available.
     if (!CTy.isForwardDecl())
       addSourceLine(&Buffer, CTy);
+
+    // No harm in adding the runtime language to the declaration.
+    unsigned RLang = CTy.getRunTimeLang();
+    if (RLang)
+      addUInt(&Buffer, dwarf::DW_AT_APPLE_runtime_class,
+              dwarf::DW_FORM_data1, RLang);
   }
 }
 
diff --git a/test/DebugInfo/objc-fwd-decl.ll b/test/DebugInfo/objc-fwd-decl.ll
new file mode 100644
index 00000000000..1a815f936c1
--- /dev/null
+++ b/test/DebugInfo/objc-fwd-decl.ll
@@ -0,0 +1,27 @@
+; RUN: llc -mtriple=x86_64-macosx %s -o %t -filetype=obj
+; RUN: llvm-dwarfdump %t | FileCheck %s
+
+; CHECK: 0x00000027:   DW_TAG_structure_type
+; CHECK: 0x0000002c:     DW_AT_declaration
+; CHECK: 0x0000002d:     DW_AT_APPLE_runtime_class
+
+%0 = type opaque
+
+@a = common global %0* null, align 8
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!9, !10, !11, !12}
+
+!0 = metadata !{i32 786449, i32 0, i32 16, metadata !"foo.m", metadata !"/Users/echristo", metadata !"clang version 3.1 (trunk 152054 trunk 152094)", i1 true, i1 false, metadata !"", i32 2, metadata !1, metadata !1, metadata !1, metadata !3} ; [ DW_TAG_compile_unit ]
+!1 = metadata !{metadata !2}
+!2 = metadata !{i32 0}
+!3 = metadata !{metadata !4}
+!4 = metadata !{metadata !5}
+!5 = metadata !{i32 786484, i32 0, null, metadata !"a", metadata !"a", metadata !"", metadata !6, i32 3, metadata !7, i32 0, i32 1, %0** @a} ; [ DW_TAG_variable ]
+!6 = metadata !{i32 786473, metadata !"foo.m", metadata !"/Users/echristo", null} ; [ DW_TAG_file_type ]
+!7 = metadata !{i32 786447, null, metadata !"", null, i32 0, i64 64, i64 64, i64 0, i32 0, metadata !8} ; [ DW_TAG_pointer_type ]
+!8 = metadata !{i32 786451, null, metadata !"FooBarBaz", metadata !6, i32 1, i32 0, i32 0, i32 0, i32 4, null, null, i32 16} ; [ DW_TAG_structure_type ]
+!9 = metadata !{i32 1, metadata !"Objective-C Version", i32 2}
+!10 = metadata !{i32 1, metadata !"Objective-C Image Info Version", i32 0}
+!11 = metadata !{i32 1, metadata !"Objective-C Image Info Section", metadata !"__DATA, __objc_imageinfo, regular, no_dead_strip"}
+!12 = metadata !{i32 4, metadata !"Objective-C Garbage Collection", i32 0}