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| author | Kaveh R. Ghazi <ghazi@caip.rutgers.edu> | 2001-03-13 13:29:40 +0000 |
|---|---|---|
| committer | Kaveh Ghazi <ghazi@gcc.gnu.org> | 2001-03-13 13:29:40 +0000 |
| commit | bf4ab281678450284b14a53089c1f364132cb203 (patch) | |
| tree | a61b19ab4ddb0df20e1986280a791f1fda4e3ada /gcc | |
| parent | e5408e52405a113827a7558f2847dc5acb0bb710 (diff) | |
| download | gcc-bf4ab281678450284b14a53089c1f364132cb203.zip gcc-bf4ab281678450284b14a53089c1f364132cb203.tar.gz gcc-bf4ab281678450284b14a53089c1f364132cb203.tar.bz2 | |
* cpp.texi (poison): Explain the macro expansion exception.
From-SVN: r40438
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 4 | ||||
| -rw-r--r-- | gcc/cpp.texi | 16 |
2 files changed, 20 insertions, 0 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 6bde0bc..b18f2733 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,7 @@ +2001-03-13 Kaveh R. Ghazi <ghazi@caip.rutgers.edu> + + * cpp.texi (poison): Explain the macro expansion exception. + 2001-03-13 Jakub Jelinek <jakub@redhat.com> * expr.c (store_expr): Add dont_store_target. If temp is already in diff --git a/gcc/cpp.texi b/gcc/cpp.texi index 8bfa8c4..57da933 100644 --- a/gcc/cpp.texi +++ b/gcc/cpp.texi @@ -1601,6 +1601,22 @@ sprintf(some_string, "hello"); @noindent will produce an error. +Note, if the poisoned identifier appears through the result of macro +expansion it @emph{won't} cause an error. So if you poison an +identifier you need not worry about system headers defining macros that +use it. + +For example, + +@example +#define strrchr rindex +#pragma GCC poison rindex +strrchr(some_string, 'h'); +@end example + +@noindent +will not produce an error. + @node Macro Pitfalls,, Poisoning, Macros @subsection Pitfalls and Subtleties of Macros @cindex problems with macros |