Fixed a crash on replaying Preamble's PP conditional stack.

Summary:
The crash occurs when the first token after a preamble is a macro
expansion.
Fixed by moving replayPreambleConditionalStack from Parser into
Preprocessor. It is now called right after the predefines file is
processed.

Reviewers: erikjv, bkramer, klimek, yvvan

Reviewed By: bkramer

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D36872

llvm-svn: 311330

1 files changed, 2 insertions, 0 deletions

diff --git a/clang/lib/Lex/Preprocessor.cpp b/clang/lib/Lex/Preprocessor.cpp
index 158d0eca278..e1294994df5 100644
--- a/clang/lib/Lex/Preprocessor.cpp
+++ b/clang/lib/Lex/Preprocessor.cpp
@@ -540,6 +540,8 @@ void Preprocessor::EnterMainSourceFile() {
 void Preprocessor::replayPreambleConditionalStack() {
   // Restore the conditional stack from the preamble, if there is one.
   if (PreambleConditionalStack.isReplaying()) {
+    assert(CurPPLexer &&
+           "CurPPLexer is null when calling replayPreambleConditionalStack.");
     CurPPLexer->setConditionalLevels(PreambleConditionalStack.getStack());
     PreambleConditionalStack.doneReplaying();
   }