Revert r234620 and others, "Actually check if lseek works instead of using a filename based heuristic." It was affected by r234615, which was reverted in r234721.

  r234620, "Actually check if lseek works instead of using a filename based heuristic."
  r234621, "Testcase for the previous commit."
  r234718, "Suppress clang/test/PCH/emit-pth.c on win32, for now while investigating."

llvm-svn: 234730

2 files changed, 6 insertions, 16 deletions

diff --git a/clang/lib/Frontend/FrontendActions.cpp b/clang/lib/Frontend/FrontendActions.cpp
index 1acaf6862e3..aa6e1732bae 100644
--- a/clang/lib/Frontend/FrontendActions.cpp
+++ b/clang/lib/Frontend/FrontendActions.cpp
@@ -599,15 +599,15 @@ void DumpTokensAction::ExecuteAction() {
 
 void GeneratePTHAction::ExecuteAction() {
   CompilerInstance &CI = getCompilerInstance();
-  llvm::raw_fd_ostream *OS =
-    CI.createDefaultOutputFile(true, getCurrentFile());
-  if (!OS)
-    return;
-
-  if (!OS->supportsSeeking()) {
+  if (CI.getFrontendOpts().OutputFile.empty() ||
+      CI.getFrontendOpts().OutputFile == "-") {
     // 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);
 }
diff --git a/clang/test/PCH/emit-pth.c b/clang/test/PCH/emit-pth.c
deleted file mode 100644
index 63144b278e8..00000000000
--- a/clang/test/PCH/emit-pth.c
+++ /dev/null
@@ -1,10 +0,0 @@
-// RUN: %clang_cc1 -triple i386-unknown-unknown -emit-pth -o %t1 %s
-// RUN: %clang_cc1 -triple i386-unknown-unknown -emit-pth -o - %s > %t2
-// RUN: cmp %t1 %t2
-// RUN: not %clang_cc1 -triple i386-unknown-unknown -emit-pth -o - %s 2>&1 | \
-// RUN: FileCheck %s
-
-// CHECK: PTH requires a seekable file for output!
-
-// MSVCRT's _lseek(SEEK_CUR) doesn't return -1 for raw_ostream::SupportSeeking.
-// REQUIRES: shell