[gold] Gate value name discarding under save-temps

[tejohnson]

Summary

This removes a couple of flags added to control this behavior, and
simply keeps all value names when save-temps is specified.

[pcc]

LGTM

Name discarding is observable using --plugin-opt=emit-llvm, but I suspect that anyone who needs names there is most likely debugging something and can get by with --plugin-opt=save-temps.

test/tools/gold/X86/comdat.ll

 ; RUN: llvm-as %s -o %t.o
 ; RUN: llvm-as %p/Inputs/comdat.ll -o %t2.o
 ; RUN: %gold -shared -o %t3.o -plugin %llvmshlibdir/LLVMgold.so %t.o %t2.o \
-; RUN:  -plugin-opt=no-discard-value-names \
-; RUN:  -plugin-opt=emit-llvm
-; RUN: llvm-dis %t3.o -o - | FileCheck %s
+; RUN:  -plugin-opt=save-temps
+; RUN: llvm-dis %t3.o.bc -o - | FileCheck %s
 
 $c1 = comdat any
 
 @v1 = weak_odr global i32 42, comdat($c1)
 define weak_odr i32 @f1(i8*) comdat($c1) {
 bb10:
   br label %bb11
 bb11:

test/tools/gold/X86/strip_names.ll

 ; RUN: llvm-as %s -o %t.o
 
 ; RUN: %gold -plugin %llvmshlibdir/LLVMgold.so \
-; RUN:    --plugin-opt=emit-llvm \
-; RUN:    --plugin-opt=no-discard-value-names \
+; RUN:    --plugin-opt=save-temps \
 ; RUN:    -shared %t.o -o %t2.o
-; RUN: llvm-dis %t2.o -o - | FileCheck %s
+; RUN: llvm-dis %t2.o.bc -o - | FileCheck %s
 
 ; RUN: %gold -plugin %llvmshlibdir/LLVMgold.so \
 ; RUN:    --plugin-opt=emit-llvm \
-; RUN:    --plugin-opt=discard-value-names \
 ; RUN:    -shared %t.o -o %t2.o
 ; RUN: llvm-dis %t2.o -o - | FileCheck ---check-prefix=NONAME %s
 
 ; CHECK: @GlobalValueName
 ; CHECK: @foo(i32 %in)
 ; CHECK: somelabel:
 ; CHECK:  %GV = load i32, i32* @GlobalValueName
 ; CHECK:  %add = add i32 %in, %GV

test/tools/gold/X86/type-merge2.ll

 ; RUN: llvm-as %s -o %t.o
 ; RUN: llvm-as %p/Inputs/type-merge2.ll -o %t2.o
 ; RUN: %gold -plugin %llvmshlibdir/LLVMgold.so \
-; RUN:    --plugin-opt=emit-llvm \
-; RUN:    --plugin-opt=no-discard-value-names \
+; RUN:    --plugin-opt=save-temps \
 ; RUN:    -shared %t.o %t2.o -o %t3.o
-; RUN: llvm-dis %t3.o -o - | FileCheck %s
+; RUN: llvm-dis %t3.o.bc -o - | FileCheck %s
 
 %zed = type { i8 }
 define void @foo()  {
   call void @bar(%zed* null)
   ret void
 }
 declare void @bar(%zed*)
 

tools/gold/gold-plugin.cpp

namespace options {
   static unsigned OptLevel = 2;
   // Default parallelism of 0 used to indicate that user did not specify.
   // Actual parallelism default value depends on implementation.
   // Currently, code generation defaults to no parallelism, whereas
   // ThinLTO uses the hardware_concurrency as the default.
   static unsigned Parallelism = 0;
 #ifdef NDEBUG
   static bool DisableVerify = true;
-  static bool DiscardValueNames = true;
 #else
   static bool DisableVerify = false;
-  static bool DiscardValueNames = false;
 #endif
   static std::string obj_path;
   static std::string extra_library_path;
   static std::string triple;
   static std::string mcpu;
   // When the thinlto plugin option is specified, only read the function
   // the information from intermediate files and write a combined
   // global index for the ThinLTO backends.
if (opt == "generate-api-file") {
       if (opt[1] < '0' || opt[1] > '3')
         message(LDPL_FATAL, "Optimization level must be between 0 and 3");
       OptLevel = opt[1] - '0';
     } else if (opt.startswith("jobs=")) {
       if (StringRef(opt_ + 5).getAsInteger(10, Parallelism))
         message(LDPL_FATAL, "Invalid parallelism level: %s", opt_ + 5);
     } else if (opt == "disable-verify") {
       DisableVerify = true;
-    } else if (opt == "discard-value-names") {
-      DiscardValueNames = true;
-    } else if (opt == "no-discard-value-names") {
-      DiscardValueNames = false;
     } else {
       // Save this option to pass to the code generator.
       // ParseCommandLineOptions() expects argv[0] to be program name. Lazily
       // add that.
       if (extra.empty())
         extra.push_back("LLVMgold");
 
       extra.push_back(opt_);

 /// pipelines.
 static void thinLTOBackendTask(claimed_file &F, const void *View,
                                ld_plugin_input_file &File,
                                raw_fd_ostream *ApiFile,
                                const ModuleSummaryIndex &CombinedIndex,
                                raw_fd_ostream *OS, unsigned TaskID) {
   // Need to use a separate context for each task
   LLVMContext Context;
-  Context.setDiscardValueNames(options::DiscardValueNames);
+  Context.setDiscardValueNames(options::TheOutputType !=
+                               options::OT_SAVE_TEMPS);
   Context.enableDebugTypeODRUniquing(); // Merge debug info types.
   Context.setDiagnosticHandler(diagnosticHandlerForContext, nullptr, true);
 
   std::unique_ptr<llvm::Module> NewModule(new llvm::Module(File.name, Context));
   IRMover L(*NewModule.get());
 
   StringSet<> Dummy;
   if (linkInModule(Context, L, F, View, File, ApiFile, Dummy, Dummy))
if (options::thinlto_index_only) {
       exit(0);
     }
 
     thinLTOBackends(ApiFile, CombinedIndex);
     return LDPS_OK;
   }
 
   LLVMContext Context;
-  Context.setDiscardValueNames(options::DiscardValueNames);
+  Context.setDiscardValueNames(options::TheOutputType !=
+                               options::OT_SAVE_TEMPS);
   Context.enableDebugTypeODRUniquing(); // Merge debug info types.
   Context.setDiagnosticHandler(diagnosticHandlerForContext, nullptr, true);
 
   std::unique_ptr<Module> Combined(new Module("ld-temp.o", Context));
   IRMover L(*Combined);
 
   StringSet<> Internalize;
   StringSet<> Maybe;