Fix rdar://6562329, a static analyzer crash Ted noticed on

wine sources.  This was happening because HighlightMacros was 
calling EnterMainFile multiple times on the same preprocessor
object and getting an assert due to the new #line stuff (the
file in question was bison output with #line directives).

The fix for this is to not reenter the file.  Instead, 
relex the tokens in raw mode, swizzle them a bit and repreprocess
the token stream.  An added bonus of this is that rewrite macros
will now hilight the macro definition as well as its uses.  Woo.

llvm-svn: 64480

1 files changed, 4 insertions, 1 deletions

diff --git a/clang/lib/Lex/Preprocessor.cpp b/clang/lib/Lex/Preprocessor.cpp
index 69aa7cb51a6..f16d83c5a2e 100644
--- a/clang/lib/Lex/Preprocessor.cpp
+++ b/clang/lib/Lex/Preprocessor.cpp
@@ -626,7 +626,10 @@ static void InitializePredefinedMacros(Preprocessor &PP,
 /// EnterMainSourceFile - Enter the specified FileID as the main source file,
 /// which implicitly adds the builtin defines etc.
 void Preprocessor::EnterMainSourceFile() {
-  
+  // We do not allow the preprocessor to reenter the main file.  Doing so will
+  // cause FileID's to accumulate information from both runs (e.g. #line
+  // information) and predefined macros aren't guaranteed to be set properly.
+  assert(NumEnteredSourceFiles == 0 && "Cannot reenter the main file!");
   FileID MainFileID = SourceMgr.getMainFileID();
   
   // Enter the main file source buffer.