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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.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@95972 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2010-02-12 08:03:27 +00:00
parent 28cbc8b512
commit 13d283d6a2
3 changed files with 30 additions and 7 deletions
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17
lib/Lex/PPDirectives.cpp
View File

@ -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();

15
test/Preprocessor/mi_opt2.c Normal file
View File

@ -0,0 +1,15 @@
// RUN: %clang_cc1 -E %s | FileCheck %s
// PR6282
// This test should not trigger the include guard optimization since
// the guard macro is defined on the first include.
#define ITERATING 1
#define X 1
#include "mi_opt2.h"
#undef X
#define X 2
#include "mi_opt2.h"
// CHECK: b: 1
// CHECK: b: 2

5
test/Preprocessor/mi_opt2.h Normal file
View File

@ -0,0 +1,5 @@
#ifndef ITERATING
a: X
#else
b: X
#endif