From 956583e98e57bea245137a7833a4b329edd897cf Mon Sep 17 00:00:00 2001
From: David Blaikie <dblaikie@gmail.com>
Date: Tue, 20 May 2014 03:23:24 +0000
Subject: [PATCH] DebugInfo: Emit function definitions within their namespace
 scope.

This workaround (presumably for ancient GDB) doesn't appear to be
required (GDB 7.5 seems to tolerate function definition DIEs in
namespace scope just fine).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209189 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/AsmPrinter/DwarfDebug.cpp         | 22 ----------
 .../namespace_function_definition.ll          | 44 +++++++++++++++++++
 2 files changed, 44 insertions(+), 22 deletions(-)
 create mode 100644 test/DebugInfo/namespace_function_definition.ll

diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index c649aa13452..5688d55fafd 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -326,28 +326,6 @@ DIE &DwarfDebug::updateSubprogramScopeDIE(DwarfCompileUnit &SPCU,
     // Pick up abstract subprogram DIE.
     SPDie = &SPCU.createAndAddDIE(dwarf::DW_TAG_subprogram, SPCU.getUnitDie());
     SPCU.addDIEEntry(*SPDie, dwarf::DW_AT_abstract_origin, *AbsSPDIE);
-  } else if (!SP.getFunctionDeclaration()) {
-    // There is not any need to generate specification DIE for a function
-    // defined at compile unit level. If a function is defined inside another
-    // function then gdb prefers the definition at top level and but does not
-    // expect specification DIE in parent function. So avoid creating
-    // specification DIE for a function defined inside a function.
-    DIScope SPContext = resolve(SP.getContext());
-    if (SP.isDefinition() && !SPContext.isCompileUnit() &&
-        !SPContext.isFile() && !isSubprogramContext(SPContext)) {
-      SPCU.addFlag(*SPDie, dwarf::DW_AT_declaration);
-
-      // Add arguments.
-      DICompositeType SPTy = SP.getType();
-      DIArray Args = SPTy.getTypeArray();
-      uint16_t SPTag = SPTy.getTag();
-      if (SPTag == dwarf::DW_TAG_subroutine_type)
-        SPCU.constructSubprogramArguments(*SPDie, Args);
-      DIE *SPDeclDie = SPDie;
-      SPDie =
-          &SPCU.createAndAddDIE(dwarf::DW_TAG_subprogram, SPCU.getUnitDie());
-      SPCU.addDIEEntry(*SPDie, dwarf::DW_AT_specification, *SPDeclDie);
-    }
   }
 
   attachLowHighPC(SPCU, *SPDie, FunctionBeginSym, FunctionEndSym);
diff --git a/test/DebugInfo/namespace_function_definition.ll b/test/DebugInfo/namespace_function_definition.ll
new file mode 100644
index 00000000000..15f39fd6d9d
--- /dev/null
+++ b/test/DebugInfo/namespace_function_definition.ll
@@ -0,0 +1,44 @@
+; 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_MIPS_linkage_name {{.*}} "_ZN2ns4funcEv"
+; CHECK-NOT: DW_TAG
+; CHECK:   DW_AT_low_pc
+; CHECK: NULL
+; CHECK: NULL
+
+; Function Attrs: nounwind uwtable
+define void @_ZN2ns4funcEv() #0 {
+entry:
+  ret void, !dbg !11
+}
+
+attributes #0 = { nounwind uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!8, !9}
+!llvm.ident = !{!10}
+
+!0 = metadata !{i32 786449, metadata !1, i32 4, metadata !"clang version 3.5.0 ", i1 false, metadata !"", i32 0, metadata !2, metadata !2, metadata !3, metadata !2, metadata !2, metadata !"", i32 1} ; [ DW_TAG_compile_unit ] [/tmp/dbginfo/namespace_function_definition.cpp] [DW_LANG_C_plus_plus]
+!1 = metadata !{metadata !"namespace_function_definition.cpp", metadata !"/tmp/dbginfo"}
+!2 = metadata !{}
+!3 = metadata !{metadata !4}
+!4 = metadata !{i32 786478, metadata !1, metadata !5, metadata !"func", metadata !"func", metadata !"_ZN2ns4funcEv", i32 2, metadata !6, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 false, void ()* @_ZN2ns4funcEv, null, null, metadata !2, i32 2} ; [ DW_TAG_subprogram ] [line 2] [def] [func]
+!5 = metadata !{i32 786489, metadata !1, null, metadata !"ns", i32 1} ; [ DW_TAG_namespace ] [ns] [line 1]
+!6 = metadata !{i32 786453, i32 0, null, metadata !"", i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !7, i32 0, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
+!7 = metadata !{null}
+!8 = metadata !{i32 2, metadata !"Dwarf Version", i32 4}
+!9 = metadata !{i32 1, metadata !"Debug Info Version", i32 1}
+!10 = metadata !{metadata !"clang version 3.5.0 "}
+!11 = metadata !{i32 3, i32 0, metadata !4, null}
-- 
2.34.1