[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
diff --git a/lib/Lex/Lexer.cpp b/lib/Lex/Lexer.cpp
index e6e7ca5..7983a6b 100644
--- a/lib/Lex/Lexer.cpp
+++ b/lib/Lex/Lexer.cpp
@@ -2595,8 +2595,14 @@
// Read the PP instance variable into an automatic variable, because
// LexEndOfFile will often delete 'this'.
Preprocessor *PPCache = PP;
+ bool EnableIncludedEOFCache = EnableIncludedEOF;
if (LexEndOfFile(Result, CurPtr-1)) // Retreat back into the file.
return; // Got a token to return.
+
+ if (EnableIncludedEOFCache) {
+ Result.setKind(tok::included_eof);
+ return;
+ }
assert(PPCache && "Raw buffer::LexEndOfFile should return a token");
return PPCache->Lex(Result);
}
@@ -3234,5 +3240,21 @@
}
goto LexNextToken; // GCC isn't tail call eliminating.
}
+
+ if (PreprocessorLexer *PPLex = PP->getCurrentLexer()) {
+ // If we #include something that contributes no tokens at all, return with
+ // a tok::included_eof instead of recursively continuing lexing.
+ // This avoids a stack overflow with a sequence of many empty #includes.
+ PPLex->setEnableIncludedEOF(true);
+ PP->Lex(Result);
+ if (Result.isNot(tok::included_eof)) {
+ if (Result.isNot(tok::eof) && Result.isNot(tok::eod))
+ PPLex->setEnableIncludedEOF(false);
+ return;
+ }
+ if (PP->isCurrentLexer(this))
+ goto LexNextToken;
+ }
+
return PP->Lex(Result);
}