[nvlink-wrapper] Remove use of symlinks

Summary:
This was intended to be a neat optimization, but some objects come from
archives so this won't work. I could write some code to detect if it
came from an archive but I don't think it's wroth the complexity when
this already doesn't work on Windows.

Author: jhuber6

clang/tools/clang-nvlink-wrapper/ClangNVLinkWrapper.cpp

@@ -236,9 +236,8 @@ void printCommands(ArrayRef<StringRef> CmdArgs) {
   if (CmdArgs.empty())
     return;
 
-  llvm::errs() << " \"" << CmdArgs.front() << "\" ";
-  llvm::errs() << llvm::join(std::next(CmdArgs.begin()), CmdArgs.end(), " ")
-               << "\n";
+  errs() << " \"" << CmdArgs.front() << "\" ";
+  errs() << join(std::next(CmdArgs.begin()), CmdArgs.end(), " ") << "\n";
 }
 
 /// A minimum symbol interface that provides the necessary information to
@@ -329,12 +328,12 @@ Expected<std::unique_ptr<lto::LTO>> createLTO(const ArgList &Args) {
   lto::ThinBackend Backend;
   unsigned Jobs = 0;
   if (auto *Arg = Args.getLastArg(OPT_jobs))
-    if (!llvm::to_integer(Arg->getValue(), Jobs) || Jobs == 0)
+    if (!to_integer(Arg->getValue(), Jobs) || Jobs == 0)
       reportError(createStringError("%s: expected a positive integer, got '%s'",
                                     Arg->getSpelling().data(),
                                     Arg->getValue()));
-  Backend = lto::createInProcessThinBackend(
-      llvm::heavyweight_hardware_concurrency(Jobs));
+  Backend =
+      lto::createInProcessThinBackend(heavyweight_hardware_concurrency(Jobs));
 
   Conf.CPU = Args.getLastArgValue(OPT_arch);
   Conf.Options = codegen::InitTargetOptionsFromCodeGenFlags(Triple);
@@ -378,7 +377,7 @@ Expected<std::unique_ptr<lto::LTO>> createLTO(const ArgList &Args) {
 
   unsigned Partitions = 1;
   if (auto *Arg = Args.getLastArg(OPT_lto_partitions))
-    if (!llvm::to_integer(Arg->getValue(), Partitions) || Partitions == 0)
+    if (!to_integer(Arg->getValue(), Partitions) || Partitions == 0)
       reportError(createStringError("%s: expected a positive integer, got '%s'",
                                     Arg->getSpelling().data(),
                                     Arg->getValue()));
@@ -510,7 +509,7 @@ Expected<SmallVector<StringRef>> getInput(const ArgList &Args) {
       InputFiles.emplace_back(std::move(*BufferOrErr), /*IsLazy=*/false);
       break;
     case file_magic::archive: {
-      Expected<std::unique_ptr<llvm::object::Archive>> LibFile =
+      Expected<std::unique_ptr<object::Archive>> LibFile =
           object::Archive::create(Buffer);
       if (!LibFile)
         return LibFile.takeError();
@@ -563,7 +562,7 @@ Expected<SmallVector<StringRef>> getInput(const ArgList &Args) {
   for (auto &Input : LinkerInput)
     if (identify_magic(Input->getBuffer()) == file_magic::bitcode)
       BitcodeFiles.emplace_back(std::move(Input));
-  llvm::erase_if(LinkerInput, [](const auto &F) { return !F; });
+  erase_if(LinkerInput, [](const auto &F) { return !F; });
 
   // Run the LTO pipeline on the extracted inputs.
   SmallVector<StringRef> Files;
@@ -574,7 +573,7 @@ Expected<SmallVector<StringRef>> getInput(const ArgList &Args) {
     lto::LTO &LTOBackend = **LTOBackendOrErr;
     for (auto &BitcodeFile : BitcodeFiles) {
       Expected<std::unique_ptr<lto::InputFile>> BitcodeFileOrErr =
-          llvm::lto::InputFile::create(*BitcodeFile);
+          lto::InputFile::create(*BitcodeFile);
       if (!BitcodeFileOrErr)
         return BitcodeFileOrErr.takeError();
 
@@ -638,7 +637,7 @@ Expected<SmallVector<StringRef>> getInput(const ArgList &Args) {
       if (std::error_code EC = sys::fs::openFileForWrite(TempFile, FD))
         reportError(errorCodeToError(EC));
       return std::make_unique<CachedFileStream>(
-          std::make_unique<llvm::raw_fd_ostream>(FD, true));
+          std::make_unique<raw_fd_ostream>(FD, true));
     };
 
     if (Error Err = LTOBackend.run(AddStream))
@@ -655,11 +654,11 @@ Expected<SmallVector<StringRef>> getInput(const ArgList &Args) {
     }
   }
 
-  // Create a link for each file to a new file ending in `.cubin`. The 'nvlink'
+  // Create a copy for each file to a new file ending in `.cubin`. The 'nvlink'
   // linker requires all NVPTX inputs to have this extension for some reason.
-  // Windows cannot create symbolic links so we just copy the whole file.
+  // We don't use a symbolic link because it's not supported on Windows and some
+  // of this input files could be extracted from an archive.
   for (auto &Input : LinkerInput) {
-#ifdef _WIN32
     auto TempFileOrErr = createTempFile(
         Args, sys::path::stem(Input->getBufferIdentifier()), "cubin");
     if (!TempFileOrErr)
@@ -669,22 +668,10 @@ Expected<SmallVector<StringRef>> getInput(const ArgList &Args) {
     if (!OutputOrErr)
       return OutputOrErr.takeError();
     std::unique_ptr<FileOutputBuffer> Output = std::move(*OutputOrErr);
-    llvm::copy(Input->getBuffer(), Output->getBufferStart());
+    copy(Input->getBuffer(), Output->getBufferStart());
     if (Error E = Output->commit())
       return E;
     Files.emplace_back(Args.MakeArgString(*TempFileOrErr));
-#else
-    SmallString<128> TempFile;
-    if (std::error_code EC = sys::fs::getPotentiallyUniqueTempFileName(
-            sys::path::stem(Input->getBufferIdentifier()), "cubin", TempFile))
-      reportError(createFileError(TempFile, EC));
-    if (std::error_code EC =
-            sys::fs::create_link(Input->getBufferIdentifier(), TempFile)) {
-      reportError(createFileError(TempFile, EC));
-    }
-    Files.emplace_back(Args.MakeArgString(TempFile));
-    TempFiles.emplace_back(std::move(TempFile));
-#endif
   }
 
   return Files;
@@ -718,8 +705,8 @@ Error runNVLink(ArrayRef<StringRef> Files, const ArgList &Args) {
     Arg->render(Args, NewLinkerArgs);
   }
 
-  llvm::transform(Files, std::back_inserter(NewLinkerArgs),
-                  [&](StringRef Arg) { return Args.MakeArgString(Arg); });
+  transform(Files, std::back_inserter(NewLinkerArgs),
+            [&](StringRef Arg) { return Args.MakeArgString(Arg); });
 
   SmallVector<StringRef> LinkerArgs({*NVLinkPath});
   if (!Args.hasArg(OPT_o))