[Darwin][Driver] Don't pass a file as object_path_lto during ThinLTO

Summary:
After r327851, Driver::GetTemporaryPath will create the file rather than
just create a potientially unqine filename. If clang driver pass the
file as parameter as -object_path_lto, ld64 will pass it back to libLTO
as GeneratedObjectsDirectory, which is going to cause a LLVM ERROR if it
is not a directory.
Now during thinLTO, pass a temp directory path to linker instread.

rdar://problem/47194182

Reviewers: arphaman, dexonsmith

Reviewed By: arphaman

Subscribers: mehdi_amini, inglorion, jkorous, cfe-commits

Differential Revision: https://reviews.llvm.org/D56608

llvm-svn: 350970

2 files changed, 25 insertions, 7 deletions

diff --git a/clang/lib/Driver/Driver.cpp b/clang/lib/Driver/Driver.cpp
index 977bff5bf71..4186fe28af4 100644
--- a/clang/lib/Driver/Driver.cpp
+++ b/clang/lib/Driver/Driver.cpp
@@ -4478,6 +4478,17 @@ std::string Driver::GetTemporaryPath(StringRef Prefix, StringRef Suffix) const {
   return Path.str();
 }
 
+std::string Driver::GetTemporaryDirectory(StringRef Prefix) const {
+  SmallString<128> Path;
+  std::error_code EC = llvm::sys::fs::createUniqueDirectory(Prefix, Path);
+  if (EC) {
+    Diag(clang::diag::err_unable_to_make_temp) << EC.message();
+    return "";
+  }
+
+  return Path.str();
+}
+
 std::string Driver::GetClPchPath(Compilation &C, StringRef BaseName) const {
   SmallString<128> Output;
   if (Arg *FpArg = C.getArgs().getLastArg(options::OPT__SLASH_Fp)) {
diff --git a/clang/lib/Driver/ToolChains/Darwin.cpp b/clang/lib/Driver/ToolChains/Darwin.cpp
index 50ecd13e698..c395c9a4430 100644
--- a/clang/lib/Driver/ToolChains/Darwin.cpp
+++ b/clang/lib/Driver/ToolChains/Darwin.cpp
@@ -224,13 +224,20 @@ void darwin::Linker::AddLinkArgs(Compilation &C, const ArgList &Args,
                    options::OPT_fno_application_extension, false))
     CmdArgs.push_back("-application_extension");
 
-  if (D.isUsingLTO()) {
-    // If we are using LTO, then automatically create a temporary file path for
-    // the linker to use, so that it's lifetime will extend past a possible
-    // dsymutil step.
-    if (Version[0] >= 116 && NeedsTempPath(Inputs)) {
-      const char *TmpPath = C.getArgs().MakeArgString(
-          D.GetTemporaryPath("cc", types::getTypeTempSuffix(types::TY_Object)));
+  if (D.isUsingLTO() && Version[0] >= 116 && NeedsTempPath(Inputs)) {
+    std::string TmpPathName;
+    if (D.getLTOMode() == LTOK_Full) {
+      // If we are using full LTO, then automatically create a temporary file
+      // path for the linker to use, so that it's lifetime will extend past a
+      // possible dsymutil step.
+      TmpPathName =
+          D.GetTemporaryPath("cc", types::getTypeTempSuffix(types::TY_Object));
+    } else if (D.getLTOMode() == LTOK_Thin)
+      // If we are using thin LTO, then create a directory instead.
+      TmpPathName = D.GetTemporaryDirectory("thinlto");
+
+    if (!TmpPathName.empty()) {
+      auto *TmpPath = C.getArgs().MakeArgString(TmpPathName);
       C.addTempFile(TmpPath);
       CmdArgs.push_back("-object_path_lto");
       CmdArgs.push_back(TmpPath);