Fix /msvclto.

Previously, bitcode files in library paths were passed to the MSVC linker.
This patch strips them.

llvm-svn: 295913

lld/COFF/Driver.cpp

@@ -422,6 +422,46 @@ static std::string getMapFile(const opt::InputArgList &Args) {
   return (OutFile.substr(0, OutFile.rfind('.')) + ".map").str();
 }
 
+static bool isBitcodeFile(StringRef Path) {
+  std::unique_ptr<MemoryBuffer> MB = check(
+      MemoryBuffer::getFile(Path, -1, false, true), "could not open " + Path);
+  StringRef Buf = MB->getBuffer();
+  return sys::fs::identify_magic(Buf) == sys::fs::file_magic::bitcode;
+}
+
+// Create response file contents and invoke the MSVC linker.
+void LinkerDriver::invokeMSVC(opt::InputArgList &Args) {
+  std::string Rsp = "/nologo ";
+
+  for (auto *Arg : Args) {
+    switch (Arg->getOption().getID()) {
+    case OPT_linkrepro:
+    case OPT_lldmap:
+    case OPT_lldmap_file:
+    case OPT_msvclto:
+      // LLD-specific options are stripped.
+      break;
+    case OPT_opt:
+      if (!StringRef(Arg->getValue()).startswith("lld"))
+        Rsp += toString(Arg) + " ";
+      break;
+    case OPT_INPUT:
+      // Bitcode files are stripped as they've been compiled to
+      // native object files.
+      if (Optional<StringRef> Path = doFindFile(Arg->getValue()))
+        if (isBitcodeFile(*Path))
+          break;
+      Rsp += quote(Arg->getValue()) + " ";
+      break;
+    default:
+      Rsp += toString(Arg) + " ";
+    }
+  }
+
+  std::vector<StringRef> ObjectFiles = Symtab.compileBitcodeFiles();
+  runMSVCLinker(Rsp, ObjectFiles);
+}
+
 void LinkerDriver::enqueueTask(std::function<void()> Task) {
   TaskQueue.push_back(std::move(Task));
 }
@@ -820,8 +860,7 @@ void LinkerDriver::link(ArrayRef<const char *> ArgsArr) {
   // If /msvclto is given, we use the MSVC linker to link LTO output files.
   // This is useful because MSVC link.exe can generate complete PDBs.
   if (Args.hasArg(OPT_msvclto)) {
-    std::vector<StringRef> ObjectFiles = Symtab.compileBitcodeFiles();
-    runMSVCLinker(Args, ObjectFiles);
+    invokeMSVC(Args);
     exit(0);
   }
 

lld/COFF/Driver.h

@@ -107,6 +107,8 @@ private:
   StringRef findDefaultEntry();
   WindowsSubsystem inferSubsystem();
 
+  void invokeMSVC(llvm::opt::InputArgList &Args);
+
   MemoryBufferRef takeBuffer(std::unique_ptr<MemoryBuffer> MB);
   void addBuffer(std::unique_ptr<MemoryBuffer> MB);
   void addArchiveBuffer(MemoryBufferRef MBRef, StringRef SymName,
@@ -178,7 +180,7 @@ void checkFailIfMismatch(StringRef Arg);
 std::unique_ptr<MemoryBuffer>
 convertResToCOFF(const std::vector<MemoryBufferRef> &MBs);
 
-void runMSVCLinker(llvm::opt::InputArgList &Args, ArrayRef<StringRef> Objects);
+void runMSVCLinker(std::string Rsp, ArrayRef<StringRef> Objects);
 
 // Create enum with OPT_xxx values for each option in Options.td
 enum {

lld/COFF/DriverUtils.cpp

@@ -626,48 +626,15 @@ convertResToCOFF(const std::vector<MemoryBufferRef> &MBs) {
   return File.getMemoryBuffer();
 }
 
-static bool isBitcodeFile(StringRef Path) {
-  std::unique_ptr<MemoryBuffer> MB = check(
-      MemoryBuffer::getFile(Path, -1, false, true), "could not open " + Path);
-  StringRef Buf = MB->getBuffer();
-  return sys::fs::identify_magic(Buf) == sys::fs::file_magic::bitcode;
-}
-
 // Run MSVC link.exe for given in-memory object files.
 // Command line options are copied from those given to LLD.
 // This is for the /msvclto option.
-void runMSVCLinker(opt::InputArgList &Args, ArrayRef<StringRef> Objects) {
+void runMSVCLinker(std::string Rsp, ArrayRef<StringRef> Objects) {
   // Write the in-memory object files to disk.
   std::vector<TemporaryFile> Temps;
-  for (StringRef S : Objects)
+  for (StringRef S : Objects) {
     Temps.emplace_back("lto", "obj", S);
-
-  // Create a response file.
-  std::string Rsp = "/nologo ";
-  for (TemporaryFile &T : Temps)
-    Rsp += quote(T.Path) + " ";
-
-  for (auto *Arg : Args) {
-    switch (Arg->getOption().getID()) {
-    case OPT_linkrepro:
-    case OPT_lldmap:
-    case OPT_lldmap_file:
-    case OPT_msvclto:
-      // LLD-specific options are stripped.
-      break;
-    case OPT_opt:
-      if (!StringRef(Arg->getValue()).startswith("lld"))
-        Rsp += toString(Arg) + " ";
-      break;
-    case OPT_INPUT:
-      // Bitcode files are stripped as they've been compiled to
-      // native object files.
-      if (!isBitcodeFile(Arg->getValue()))
-        Rsp += quote(Arg->getValue()) + " ";
-      break;
-    default:
-      Rsp += toString(Arg) + " ";
-    }
+    Rsp += quote(Temps.back().Path) + " ";
   }
 
   log("link.exe " + Rsp);

lld/test/COFF/msvclto.ll

@@ -1,6 +1,7 @@
-; RUN: llvm-as -o %t1.obj %s
-; RUN: llvm-mc -triple=x86_64-pc-windows-msvc -filetype=obj -o %t2.obj %p/Inputs/msvclto.s
-; RUN: lld-link %t1.obj %t2.obj /msvclto /out:%t.exe /opt:lldlto=1 /opt:icf \
+; RUN: llvm-as -o %t.obj %s
+; RUN: mkdir -p %t.dir
+; RUN: llvm-mc -triple=x86_64-pc-windows-msvc -filetype=obj -o %t.dir/bitcode.obj %p/Inputs/msvclto.s
+; RUN: lld-link %t.obj %t.dir/bitcode.obj /msvclto /out:%t.exe /opt:lldlto=1 /opt:icf \
 ; RUN:   /entry:main /verbose > %t.log || true
 ; RUN: FileCheck %s < %t.log