From aa1cccbbef2bc52457666334bee0ea264b330295 Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Fri, 12 Feb 2010 08:03:27 +0000 Subject: Fix PR6282: the include guard optimization cannot happen if the guard macro is already defined for the first occurrence of the header. If it is, the body will be skipped and not be properly analyzed for the include guard optimization. llvm-svn: 95972 --- clang/lib/Lex/PPDirectives.cpp | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) (limited to 'clang/lib') diff --git a/clang/lib/Lex/PPDirectives.cpp b/clang/lib/Lex/PPDirectives.cpp index b0e784bcd96..4803c5ab85d 100644 --- a/clang/lib/Lex/PPDirectives.cpp +++ b/clang/lib/Lex/PPDirectives.cpp @@ -1514,18 +1514,21 @@ void Preprocessor::HandleIfdefDirective(Token &Result, bool isIfndef, // Check to see if this is the last token on the #if[n]def line. CheckEndOfDirective(isIfndef ? "ifndef" : "ifdef"); + IdentifierInfo *MII = MacroNameTok.getIdentifierInfo(); + MacroInfo *MI = getMacroInfo(MII); + if (CurPPLexer->getConditionalStackDepth() == 0) { - // If the start of a top-level #ifdef, inform MIOpt. - if (!ReadAnyTokensBeforeDirective) { + // If the start of a top-level #ifdef and if the macro is not defined, + // inform MIOpt that this might be the start of a proper include guard. + // Otherwise it is some other form of unknown conditional which we can't + // handle. + if (!ReadAnyTokensBeforeDirective && MI == 0) { assert(isIfndef && "#ifdef shouldn't reach here"); - CurPPLexer->MIOpt.EnterTopLevelIFNDEF(MacroNameTok.getIdentifierInfo()); + CurPPLexer->MIOpt.EnterTopLevelIFNDEF(MII); } else CurPPLexer->MIOpt.EnterTopLevelConditional(); } - IdentifierInfo *MII = MacroNameTok.getIdentifierInfo(); - MacroInfo *MI = getMacroInfo(MII); - // If there is a macro, process it. if (MI) // Mark it used. MI->setIsUsed(true); @@ -1558,7 +1561,7 @@ void Preprocessor::HandleIfDirective(Token &IfToken, // If this condition is equivalent to #ifndef X, and if this is the first // directive seen, handle it for the multiple-include optimization. if (CurPPLexer->getConditionalStackDepth() == 0) { - if (!ReadAnyTokensBeforeDirective && IfNDefMacro) + if (!ReadAnyTokensBeforeDirective && IfNDefMacro && ConditionalTrue) CurPPLexer->MIOpt.EnterTopLevelIFNDEF(IfNDefMacro); else CurPPLexer->MIOpt.EnterTopLevelConditional(); -- cgit v1.2.3