[DWARFv5][DWARFLinker] avoid stripping template names for .debug_names.

DWARFLinker puts three names for subprograms into the .apple_names and
.debug_names: short name, linkage name, name without template parameters.

DW_TAG_subprogram
   DW_AT_linkage_name "_Z3fooIcEvv"
   DW_AT_name "foo<char>"

short name: "foo<char>"
linkage name: "_Z3fooIcEvv"
name without template parameters: "foo"

DWARFv5 does not require stripping template parameters for subprogram name.
Current llvm-dwarfdump --verify reports the error if names stored in
accelerator table do not match with DIE name(name with stripped template
parameters stored in accelerator table does not match with original DIE name).
This patch does not store name without template parameters into the .debug_names table.

Differential Revision: https://reviews.llvm.org/D153869

llvm/include/llvm/DWARFLinker/DWARFLinker.h

@@ -361,6 +361,9 @@ class DWARFLinker {
   void addAccelTableKind(AccelTableKind Kind) {
     assert(!llvm::is_contained(Options.AccelTables, Kind));
     Options.AccelTables.emplace_back(Kind);
+
+    if (Kind == AccelTableKind::Apple)
+      Options.CanStripTemplateName = true;
   }
 
   /// Set prepend path for clang modules.
@@ -882,6 +885,7 @@ class DWARFLinker {
 
     /// The accelerator table kinds
     SmallVector<AccelTableKind, 1> AccelTables;
+    bool CanStripTemplateName = false;
 
     /// Prepend path for the clang modules.
     std::string PrependPath;

llvm/lib/DWARFLinker/DWARFLinker.cpp

@@ -192,7 +192,8 @@ bool DWARFLinker::DIECloner::getDIENames(const DWARFDie &Die,
   if (!Info.MangledName)
     Info.MangledName = Info.Name;
 
-  if (StripTemplate && Info.Name && Info.MangledName != Info.Name) {
+  if (StripTemplate && Linker.Options.CanStripTemplateName && Info.Name &&
+      Info.MangledName != Info.Name) {
     StringRef Name = Info.Name.getString();
     if (std::optional<StringRef> StrippedName = StripTemplateParameters(Name))
       Info.NameWithoutTemplate = StringPool.getEntry(*StrippedName);

llvm/test/tools/dsymutil/X86/dwarf5-accel.test

@@ -0,0 +1,34 @@
+## This test checks that DIE name with stripped template parameters
+## is not stored into .debug_name section.
+
+## cat dwarf5-accel.cpp
+##
+## template<typename A> void foo() {};
+##
+## int main ( void ) {
+##   foo<char>();
+##   return 0;
+## }
+
+## $ clang -gdwarf-5 dwarf5-accel.cpp -c -o dwarf5-accel.o
+
+#RUN: dsymutil -accelerator=Dwarf -oso-prepend-path %p/Inputs -y %s -o %t.dSYM
+#RUN: llvm-dwarfdump --verify  %t.dSYM | FileCheck %s --check-prefix VERIFY
+#RUN: llvm-dwarfdump -a --verbose  %t.dSYM | FileCheck %s
+
+#VERIFY: No errors.
+
+#CHECK: .debug_names
+#CHECK-NOT: "foo"
+#CHECK: _Z3fooIcEvv
+#CHECK-NOT: "foo"
+#CHECK: "foo<char>"
+
+---
+triple:          'x86_64-apple-darwin'
+objects:
+  - filename:        'dwarf5-accel.o'
+    timestamp:       1676048242
+    symbols:
+      - { sym: _main, objAddr: 0x0000000000000000, binAddr: 0x0000000100000AB0, size: 0x00000008 }
+      - { sym: __Z3fooIcEvv, objAddr: 0x0000000000000020, binAddr: 0x0000000100000BB0, size: 0x00000008 }