gold-plugin: Simplify naming of object files created with save-temps or obj-path.

[pcc]

Summary

Now we never append a number to the file name for task ID 0.

[davide]

LGTM. I assume we need a similar change in lld? (I have the lld LTO code out of cache, so, in case we don't, ignore me).

[pcc]

Sure, I see no harm in doing the same thing in lld. r293138.

llvm/trunk/test/tools/gold/X86/parallel.ll

 ; RUN: llvm-as -o %t.bc %s
-; RUN: rm -f %t.opt.bc0 %t.opt.bc1 %t.o0 %t.o1
+; RUN: rm -f %t.0.5.precodegen.bc %t.1.5.precodegen.bc %t.o %t.o1
 ; RUN: env LD_PRELOAD=%llvmshlibdir/LLVMgold.so %gold -plugin %llvmshlibdir/LLVMgold.so -u foo -u bar -plugin-opt lto-partitions=2 -plugin-opt save-temps -m elf_x86_64 -o %t %t.bc
 ; RUN: llvm-dis %t.0.5.precodegen.bc -o - | FileCheck --check-prefix=CHECK-BC0 %s
 ; RUN: llvm-dis %t.1.5.precodegen.bc -o - | FileCheck --check-prefix=CHECK-BC1 %s
-; RUN: llvm-nm %t.o0 | FileCheck --check-prefix=CHECK0 %s
+; RUN: llvm-nm %t.o | FileCheck --check-prefix=CHECK0 %s
 ; RUN: llvm-nm %t.o1 | FileCheck --check-prefix=CHECK1 %s
 
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-unknown-linux-gnu"
 
 ; CHECK-BC0: define void @foo
 ; CHECK-BC0: declare void @bar
 ; CHECK0-NOT: bar

llvm/trunk/tools/gold/gold-plugin.cpp

 static bool IsExecutable = false;
 static Optional<Reloc::Model> RelocationModel;
 static std::string output_name = "";
 static std::list<claimed_file> Modules;
 static DenseMap<int, void *> FDToLeaderHandle;
 static StringMap<ResolutionInfo> ResInfo;
 static std::vector<std::string> Cleanup;
 static llvm::TargetOptions TargetOpts;
-static size_t MaxTasks;
 
 namespace options {
   enum OutputType {
     OT_NORMAL,
     OT_DISABLE,
     OT_BC_ONLY,
     OT_SAVE_TEMPS
   };
static void recordFile(std::string Filename, bool TempOutFile) {
   if (TempOutFile)
     Cleanup.push_back(Filename.c_str());
 }
 
 /// Return the desired output filename given a base input name, a flag
 /// indicating whether a temp file should be generated, and an optional task id.
 /// The new filename generated is returned in \p NewFilename.
 static void getOutputFileName(SmallString<128> InFilename, bool TempOutFile,
-                              SmallString<128> &NewFilename, int TaskID = -1) {
+                              SmallString<128> &NewFilename, int TaskID) {
   if (TempOutFile) {
     std::error_code EC =
         sys::fs::createTemporaryFile("lto-llvm", "o", NewFilename);
     if (EC)
       message(LDPL_FATAL, "Could not create temporary file: %s",
               EC.message().c_str());
   } else {
     NewFilename = InFilename;
-    if (TaskID >= 0)
+    if (TaskID > 0)
       NewFilename += utostr(TaskID);
   }
 }
 
 static CodeGenOpt::Level getCGOptLevel() {
   switch (options::OptLevel) {
   case 0:
     return CodeGenOpt::None;
static ld_plugin_status allSymbolsReadHook() {
   SmallString<128> Filename;
   // Note that getOutputFileName will append a unique ID for each task
   if (!options::obj_path.empty())
     Filename = options::obj_path;
   else if (options::TheOutputType == options::OT_SAVE_TEMPS)
     Filename = output_name + ".o";
   bool SaveTemps = !Filename.empty();
 
-  MaxTasks = Lto->getMaxTasks();
+  size_t MaxTasks = Lto->getMaxTasks();
   std::vector<uintptr_t> IsTemporary(MaxTasks);
   std::vector<SmallString<128>> Filenames(MaxTasks);
 
   auto AddStream =
       [&](size_t Task) -> std::unique_ptr<lto::NativeObjectStream> {
     IsTemporary[Task] = !SaveTemps;
     getOutputFileName(Filename, /*TempOutFile=*/!SaveTemps, Filenames[Task],
-                      MaxTasks > 1 ? Task : -1);
+                      Task);
     int FD;
     std::error_code EC =
         sys::fs::openFileForWrite(Filenames[Task], FD, sys::fs::F_None);
     if (EC)
       message(LDPL_FATAL, "Could not open file %s: %s", Filenames[Task].c_str(),
               EC.message().c_str());
     return llvm::make_unique<lto::NativeObjectStream>(
         llvm::make_unique<llvm::raw_fd_ostream>(FD, true));