Merging r340025:

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r340025 | erichkeane | 2018-08-17 06:43:39 -0700 (Fri, 17 Aug 2018) | 8 lines

Fix for bug 38508 - Don't do PCH processing when only generating preprocessor output

This clang-cl driver change removes the PCH options when we are only generating
preprocessed output. This is similar to the behavior of Y-.

Patch by: mikerice
Differential Revision: https://reviews.llvm.org/D50640

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llvm-svn: 345311

1 files changed, 4 insertions, 3 deletions

diff --git a/clang/lib/Driver/Driver.cpp b/clang/lib/Driver/Driver.cpp
index 952a716cb6e..b69d65ea907 100644
--- a/clang/lib/Driver/Driver.cpp
+++ b/clang/lib/Driver/Driver.cpp
@@ -2998,9 +2998,10 @@ void Driver::BuildActions(Compilation &C, DerivedArgList &Args,
     Args.eraseArg(options::OPT__SLASH_Yc);
     YcArg = nullptr;
   }
-  if (Args.hasArg(options::OPT__SLASH_Y_)) {
-    // /Y- disables all pch handling.  Rather than check for it everywhere,
-    // just remove clang-cl pch-related flags here.
+  if (FinalPhase == phases::Preprocess || Args.hasArg(options::OPT__SLASH_Y_)) {
+    // If only preprocessing or /Y- is used, all pch handling is disabled.
+    // Rather than check for it everywhere, just remove clang-cl pch-related
+    // flags here.
     Args.eraseArg(options::OPT__SLASH_Fp);
     Args.eraseArg(options::OPT__SLASH_Yc);
     Args.eraseArg(options::OPT__SLASH_Yu);