[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

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@350970 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 40 insertions, 7 deletions

diff --git a/include/clang/Driver/Driver.h b/include/clang/Driver/Driver.h
index 31c17272ca..494336d672 100644
--- a/include/clang/Driver/Driver.h
+++ b/include/clang/Driver/Driver.h
@@ -505,6 +505,10 @@ public:
   /// GCC goes to extra lengths here to be a bit more robust.
   std::string GetTemporaryPath(StringRef Prefix, StringRef Suffix) const;
 
+  /// GetTemporaryDirectory - Return the pathname of a temporary directory to
+  /// use as part of compilation; the directory will have the given prefix.
+  std::string GetTemporaryDirectory(StringRef Prefix) const;
+
   /// Return the pathname of the pch file in clang-cl mode.
   std::string GetClPchPath(Compilation &C, StringRef BaseName) const;
 
diff --git a/lib/Driver/Driver.cpp b/lib/Driver/Driver.cpp
index 977bff5bf7..4186fe28af 100644
--- a/lib/Driver/Driver.cpp
+++ b/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/lib/Driver/ToolChains/Darwin.cpp b/lib/Driver/ToolChains/Darwin.cpp
index 50ecd13e69..c395c9a443 100644
--- a/lib/Driver/ToolChains/Darwin.cpp
+++ b/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);
diff --git a/test/Driver/darwin-ld-lto.c b/test/Driver/darwin-ld-lto.c
index 2725df4f5f..80b23b9b2c 100644
--- a/test/Driver/darwin-ld-lto.c
+++ b/test/Driver/darwin-ld-lto.c
@@ -17,3 +17,14 @@
 // RUN: %clang -target x86_64-apple-darwin10 -### %s \
 // RUN:   -ccc-install-dir %S/dummytestdir -mlinker-version=133 2> %t.log
 // RUN: FileCheck -check-prefix=LINK_LTOLIB_PATH %s -input-file %t.log
+
+
+// Check that -object_lto_path is passed correctly to ld64
+// RUN: %clang -target x86_64-apple-darwin10 %s -flto=full -### 2>&1 | \
+// RUN:   FileCheck -check-prefix=FULL_LTO_OBJECT_PATH %s
+// FULL_LTO_OBJECT_PATH: /usr/bin/ld
+// FULL_LTO_OBJECT_PATH-SAME: "-object_path_lto" "{{[a-zA-Z0-9_\/]+\/cc\-[a-zA-Z0-9_]+.o}}"
+// RUN: %clang -target x86_64-apple-darwin10 %s -flto=thin -### 2>&1 | \
+// RUN:   FileCheck -check-prefix=THIN_LTO_OBJECT_PATH %s
+// THIN_LTO_OBJECT_PATH: /usr/bin/ld
+// THIN_LTO_OBJECT_PATH-SAME: "-object_path_lto" "{{[a-zA-Z0-9_\/]+\/thinlto\-[a-zA-Z0-9_]+}}"