[preprocessor] When #including something that contributes no tokens at all,

don't recursively continue lexing.

This avoids a stack overflow with a sequence of many empty #includes.
rdar://11988695

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@167801 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 11 insertions, 1 deletions

diff --git a/include/clang/Lex/PreprocessorLexer.h b/include/clang/Lex/PreprocessorLexer.h
index 20fb8a0c48..b85729dd08 100644
--- a/include/clang/Lex/PreprocessorLexer.h
+++ b/include/clang/Lex/PreprocessorLexer.h
@@ -61,6 +61,10 @@ protected:
   /// Note that in raw mode that the PP pointer may be null.
   bool LexingRawMode;
 
+  /// \brief When true, if EOF of the current lexer is found, tok::included_eof
+  /// is returned instead of continuing lexing higher in the include stack.
+  bool EnableIncludedEOF;
+
   /// \brief A state machine that detects the \#ifndef-wrapping a file
   /// idiom for the multiple-include optimization.
   MultipleIncludeOpt MIOpt;
@@ -79,7 +83,8 @@ protected:
     : PP(0), InitialNumSLocEntries(0),
       ParsingPreprocessorDirective(false),
       ParsingFilename(false),
-      LexingRawMode(false) {}
+      LexingRawMode(false),
+      EnableIncludedEOF(false) {}
 
   virtual ~PreprocessorLexer() {}
 
@@ -147,6 +152,11 @@ public:
   /// \brief Return true if this lexer is in raw mode or not.
   bool isLexingRawMode() const { return LexingRawMode; }
 
+  /// \brief When true, if EOF of the current lexer is found, tok::included_eof
+  /// is returned instead of continuing lexing higher in the include stack.
+  /// False is the default behavior.
+  void setEnableIncludedEOF(bool Enable) { EnableIncludedEOF = Enable; }
+
   /// \brief Return the preprocessor object for this lexer.
   Preprocessor *getPP() const { return PP; }