Take an entirely different approach to handling the "parsing" of

__import__ within the preprocessor, since the prior one foolishly
assumed that Preprocessor::Lex() was re-entrant. We now handle
__import__ at the top level (only), after macro expansion. This should
fix the buildbot failures.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@138704 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 10 insertions, 1 deletions

diff --git a/include/clang/Basic/IdentifierTable.h b/include/clang/Basic/IdentifierTable.h
index 424a3440d4..017af5caee 100644
--- a/include/clang/Basic/IdentifierTable.h
+++ b/include/clang/Basic/IdentifierTable.h
@@ -252,7 +252,7 @@ private:
   void RecomputeNeedsHandleIdentifier() {
     NeedsHandleIdentifier =
       (isPoisoned() | hasMacroDefinition() | isCPlusPlusOperatorKeyword() |
-       isExtensionToken() | (getTokenID() == tok::kw___import__));
+       isExtensionToken());
   }
 };
 
diff --git a/include/clang/Lex/Preprocessor.h b/include/clang/Lex/Preprocessor.h
index 1ab6411e98..b14c7e8382 100644
--- a/include/clang/Lex/Preprocessor.h
+++ b/include/clang/Lex/Preprocessor.h
@@ -118,6 +118,9 @@ class Preprocessor : public llvm::RefCountedBase<Preprocessor> {
   /// \brief Whether we have already loaded macros from the external source.
   mutable bool ReadMacrosFromExternalSource : 1;
 
+  /// \brief Tracks the depth of Lex() Calls.
+  unsigned LexDepth;
+  
   /// Identifiers - This is mapping/lookup information for all identifiers in
   /// the program, including program keywords.
   mutable IdentifierTable Identifiers;
@@ -531,6 +534,7 @@ public:
   /// Lex - To lex a token from the preprocessor, just pull a token from the
   /// current lexer or macro object.
   void Lex(Token &Result) {
+    ++LexDepth;
     if (CurLexer)
       CurLexer->Lex(Result);
     else if (CurPTHLexer)
@@ -539,6 +543,11 @@ public:
       CurTokenLexer->Lex(Result);
     else
       CachingLex(Result);
+    --LexDepth;
+    
+    // If we have the __import__ keyword, handle the module import now.
+    if (Result.getKind() == tok::kw___import__ && LexDepth == 0)
+      HandleModuleImport(Result);
   }
 
   /// LexNonComment - Lex a token.  If it's a comment, keep lexing until we get