Merging r311330:

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r311330 | ibiryukov | 2017-08-21 05:03:08 -0700 (Mon, 21 Aug 2017) | 16 lines

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
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git-svn-id: https://llvm.org/svn/llvm-project/cfe/branches/release_50@311591 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 14 insertions, 1 deletions

diff --git a/lib/Lex/PPLexerChange.cpp b/lib/Lex/PPLexerChange.cpp
index 5a589d6a17..36d7028da6 100644
--- a/lib/Lex/PPLexerChange.cpp
+++ b/lib/Lex/PPLexerChange.cpp
@@ -458,10 +458,16 @@ bool Preprocessor::HandleEndOfFile(Token &Result, bool isEndOfMacro) {
       SourceMgr.setNumCreatedFIDsForFileID(CurPPLexer->getFileID(), NumFIDs);
     }
 
+    bool ExitedFromPredefinesFile = false;
     FileID ExitedFID;
-    if (Callbacks && !isEndOfMacro && CurPPLexer)
+    if (!isEndOfMacro && CurPPLexer) {
       ExitedFID = CurPPLexer->getFileID();
 
+      assert(PredefinesFileID.isValid() &&
+             "HandleEndOfFile is called before PredefinesFileId is set");
+      ExitedFromPredefinesFile = (PredefinesFileID == ExitedFID);
+    }
+
     if (LeavingSubmodule) {
       // We're done with this submodule.
       Module *M = LeaveSubmodule(/*ForPragma*/false);
@@ -489,6 +495,11 @@ bool Preprocessor::HandleEndOfFile(Token &Result, bool isEndOfMacro) {
                              PPCallbacks::ExitFile, FileType, ExitedFID);
     }
 
+    // Restore conditional stack from the preamble right after exiting from the
+    // predefines file.
+    if (ExitedFromPredefinesFile)
+      replayPreambleConditionalStack();
+
     // Client should lex another token unless we generated an EOM.
     return LeavingSubmodule;
   }
diff --git a/lib/Lex/Preprocessor.cpp b/lib/Lex/Preprocessor.cpp
index d1dc8e1c00..7979be773a 100644
--- a/lib/Lex/Preprocessor.cpp
+++ b/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();
   }