1 files changed, 34 insertions, 1 deletions
diff --git a/lld/COFF/Driver.cpp b/lld/COFF/Driver.cpp
index ffa900d42f2d..155e4ca6ee3f 100644
--- a/lld/COFF/Driver.cpp
+++ b/lld/COFF/Driver.cpp
@@ -436,17 +436,26 @@ void LinkerDriver::parseDirectives(InputFile *file) {
 // Find file from search paths. You can omit ".obj", this function takes
 // care of that. Note that the returned path is not guaranteed to exist.
 StringRef LinkerDriver::doFindFile(StringRef filename) {
+  auto getFilename = [](StringRef filename) -> StringRef {
+    if (config->vfs)
+      if (auto statOrErr = config->vfs->status(filename))
+        return saver().save(statOrErr->getName());
+    return filename;
+  };
+
   bool hasPathSep = (filename.find_first_of("/\\") != StringRef::npos);
   if (hasPathSep)
-    return filename;
+    return getFilename(filename);
   bool hasExt = filename.contains('.');
   for (StringRef dir : searchPaths) {
     SmallString<128> path = dir;
     sys::path::append(path, filename);
+    path = SmallString<128>{getFilename(path.str())};
     if (sys::fs::exists(path.str()))
       return saver().save(path.str());
     if (!hasExt) {
       path.append(".obj");
+      path = SmallString<128>{getFilename(path.str())};
       if (sys::fs::exists(path.str()))
         return saver().save(path.str());
     }
@@ -1349,6 +1358,28 @@ Optional<std::string> getReproduceFile(const opt::InputArgList &args) {
   return None;
 }
 
+static std::unique_ptr<llvm::vfs::FileSystem>
+getVFS(const opt::InputArgList &args) {
+  using namespace llvm::vfs;
+
+  const opt::Arg *arg = args.getLastArg(OPT_vfsoverlay);
+  if (!arg)
+    return nullptr;
+
+  auto bufOrErr = llvm::MemoryBuffer::getFile(arg->getValue());
+  if (!bufOrErr) {
+    checkError(errorCodeToError(bufOrErr.getError()));
+    return nullptr;
+  }
+
+  if (auto ret = vfs::getVFSFromYAML(std::move(*bufOrErr), /*DiagHandler*/ nullptr,
+                             arg->getValue()))
+    return ret;
+
+  error("Invalid vfs overlay");
+  return nullptr;
+}
+
 void LinkerDriver::linkerMain(ArrayRef<const char *> argsArr) {
   ScopedTimer rootTimer(ctx.rootTimer);
 
@@ -1390,6 +1421,8 @@ void LinkerDriver::linkerMain(ArrayRef<const char *> argsArr) {
     errorHandler().errorLimit = n;
   }
 
+  config->vfs = getVFS(args);
+
   // Handle /help
   if (args.hasArg(OPT_help)) {
     printHelp(argsArr[0]);