[cfe-commits] r44285 - in /cfe/trunk: Lex/Preprocessor.cpp test/Preprocessor/macro_disable4.c
Chris Lattner
sabre at nondot.org
Thu Nov 22 22:50:23 PST 2007
Author: lattner
Date: Fri Nov 23 00:50:21 2007
New Revision: 44285
URL: http://llvm.org/viewvc/llvm-project?rev=44285&view=rev
Log:
Fix PR1820, an incredibly subtle macro expansion bug that Neil discovered.
Neil, please review this fix.
Added:
cfe/trunk/test/Preprocessor/macro_disable4.c
Modified:
cfe/trunk/Lex/Preprocessor.cpp
Modified: cfe/trunk/Lex/Preprocessor.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/Lex/Preprocessor.cpp?rev=44285&r1=44284&r2=44285&view=diff
==============================================================================
--- cfe/trunk/Lex/Preprocessor.cpp (original)
+++ cfe/trunk/Lex/Preprocessor.cpp Fri Nov 23 00:50:21 2007
@@ -941,6 +941,16 @@
// If this is a comment token in the argument list and we're just in
// -C mode (not -CC mode), discard the comment.
continue;
+ } else if (Tok.is(tok::identifier)) {
+ // Reading macro arguments can cause macros that we are currently
+ // expanding from to be popped off the expansion stack. Doing so causes
+ // them to be reenabled for expansion. Here we record whether any
+ // identifiers we lex as macro arguments correspond to disabled macros.
+ // If so, we mark the token as noexpand. This is a subtle aspect of
+ // C99 6.10.3.4p2.
+ if (MacroInfo *MI = getMacroInfo(Tok.getIdentifierInfo()))
+ if (!MI->isEnabled())
+ Tok.setFlag(Token::DisableExpand);
}
ArgTokens.push_back(Tok);
Added: cfe/trunk/test/Preprocessor/macro_disable4.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Preprocessor/macro_disable4.c?rev=44285&view=auto
==============================================================================
--- cfe/trunk/test/Preprocessor/macro_disable4.c (added)
+++ cfe/trunk/test/Preprocessor/macro_disable4.c Fri Nov 23 00:50:21 2007
@@ -0,0 +1,6 @@
+// RUN: clang -P -E %s | grep 'int f(void)'
+// PR1820
+
+#define f(x) h(x
+#define h(x) x(void)
+extern int f(f));
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