Actually check if lseek works instead of using a filename based heuristic.

llvm-svn: 234620

1 files changed, 6 insertions, 6 deletions

diff --git a/clang/lib/Frontend/FrontendActions.cpp b/clang/lib/Frontend/FrontendActions.cpp
index 622ca8241c2..082bf92f097 100644
--- a/clang/lib/Frontend/FrontendActions.cpp
+++ b/clang/lib/Frontend/FrontendActions.cpp
@@ -600,15 +600,15 @@ void DumpTokensAction::ExecuteAction() {
 
 void GeneratePTHAction::ExecuteAction() {
   CompilerInstance &CI = getCompilerInstance();
-  if (CI.getFrontendOpts().OutputFile.empty() ||
-      CI.getFrontendOpts().OutputFile == "-") {
+  llvm::raw_fd_ostream *OS =
+    CI.createDefaultOutputFile(true, getCurrentFile());
+  if (!OS)
+    return;
+
+  if (!OS->supportsSeeking()) {
     // FIXME: Don't fail this way.
-    // FIXME: Verify that we can actually seek in the given file.
     llvm::report_fatal_error("PTH requires a seekable file for output!");
   }
-  llvm::raw_fd_ostream *OS =
-    CI.createDefaultOutputFile(true, getCurrentFile());
-  if (!OS) return;
 
   CacheTokens(CI.getPreprocessor(), OS);
 }