[Bug middle-end/19967] [4.0 Regression] built-in folding causes excess diagnostics

["joseph at codesourcery dot com" <gcc-bugzilla at gcc dot gnu dot org>]

------- Additional Comments From joseph at codesourcery dot com  2005-02-15 01:37 -------
Subject: Re:  [4.0 Regression] built-in folding causes
 excess diagnostics

On Tue, 15 Feb 2005, pinskia at gcc dot gnu dot org wrote:

> Caused by:
> 2004-09-15  Jakub Jelinek  <jakub@redhat.com>
> 
>         * expr.c (string_constant): Handle also read-only variables
>         initialized to string literals.

I'm not sure how useful it is to treat that patch as the cause.  I used 
__func__ to keep the example within ISO C (apart from the cases of the 
non-standard functions index and rindex).  You can get the same effect 
with "f" in place of __func__ and -Wwrite-strings (though the constant is 
const char * with -Wwrite-strings, these standard functions remove 
constness found in their argument in C).  I suspect you'll find a 
different causing patch for

char *strchr(const char *, int);
char *strrchr(const char *, int);
char *index(const char *, int);
char *rindex(const char *, int);
char *strpbrk(const char *, const char *);
char *strstr(const char *, const char *);
char *p;
void
f (void)
{
  p = strchr("f", 'f');
  p = strrchr("f", 'f');
  p = index("f", 'f');
  p = rindex("f", 'f');
  p = strpbrk("f", "f");
  p = strstr("f", "f");
}

with -Wwrite-strings, although the underlying bug is the same.



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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19967