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Fix presumed type clash in "ld - fix for bug 13343"
- From: Hans-Peter Nilsson <hans-peter dot nilsson at axis dot com>
- To: amodra at gmail dot com
- Cc: binutils at sourceware dot org
- Date: Sat, 18 Feb 2012 05:19:55 +0100
- Subject: Fix presumed type clash in "ld - fix for bug 13343"
> From: Alan Modra <amodra@gmail.com>
> Date: Fri, 17 Feb 2012 15:13:47 +0100
> * ldmisc.c (vfinfo <%S>): Take file name and line number from
> etree_type arg, or use current if arg is NULL.
> Index: ld/ldmisc.c
> @@ -240,12 +240,19 @@ vfinfo (FILE *fp, const char *fmt, va_li
>
> case 'S':
> /* Print script file and linenumber. */
> - if (parsing_defsym)
> - fprintf (fp, "--defsym %s", lex_string);
> - else if (ldfile_input_filename != NULL)
> - fprintf (fp, "%s:%u", ldfile_input_filename, lineno);
> - else
> - fprintf (fp, _("built in linker script:%u"), lineno);
> + {
> + node_type node;
> + etree_type *tp = va_arg (arg, etree_type *);
> +
> + if (tp == NULL)
> + {
> + tp = (etree_type *) &node;
> + tp->type.filename = ldlex_filename ();
> + tp->type.lineno = lineno;
> + }
> + if (tp->type.filename != NULL)
> + fprintf (fp, "%s:%u", tp->type.filename, tp->type.lineno)> ;
> + }
> break;
This yields, for gcc-4.4.3 and 4.4.5 (but not for 4.1.2 nor 4.3.0):
gcc -DHAVE_CONFIG_H -I. -I/tmp/hpautotest-gcc1/binusrc/src/ld -I. -I/tmp/hpautotest-gcc1/binusrc/src/ld -I../bfd -I/tmp/hpautotest-gcc1/binusrc/src/ld/../bfd -I/tmp/hpautotest-gcc1/binusrc/src/ld/../include -g -O2 -DENABLE_PLUGINS -DLOCALEDIR="\"/tmp/hpautotest-gcc1/cris-elf/pre/share/locale\"" -W -Wall -Wstrict-prototypes -Wmissing-prototypes -Wshadow -Werror -g -O2 -MT ldmisc.o -MD -MP -MF .deps/ldmisc.Tpo -c -o ldmisc.o /tmp/hpautotest-gcc1/binusrc/src/ld/ldmisc.c
cc1: warnings being treated as errors
/tmp/hpautotest-gcc1/binusrc/src/ld/ldmisc.c: In function 'vfinfo':
/tmp/hpautotest-gcc1/binusrc/src/ld/ldmisc.c:251: error: dereferencing pointer 'tp' does break strict-aliasing rules
/tmp/hpautotest-gcc1/binusrc/src/ld/ldmisc.c:250: error: dereferencing pointer 'tp' does break strict-aliasing rules
/tmp/hpautotest-gcc1/binusrc/src/ld/ldmisc.c:249: note: initialized from here
make[4]: *** [ldmisc.o] Error 1
At least one of us should update the gcc used for
development. :)
Regardless of the validity of type-punning for a pointee that's
actually a member in the union being the type pointed to, there
are enough of gcc-4.4.3 and .5 out there that IMHO it makes
sense to pacify them by making the code clearer. Or shorter,
just say no to casts.
Ok?
ld:
* ldmisc.c (vfinfo <%S>): Use same type and avoid cast for
temporary variable node used for NULL argument.
Index: ldmisc.c
===================================================================
RCS file: /cvs/src/src/ld/ldmisc.c,v
retrieving revision 1.41
diff -p -u -r1.41 ldmisc.c
--- ldmisc.c 17 Feb 2012 14:09:57 -0000 1.41
+++ ldmisc.c 18 Feb 2012 04:07:15 -0000
@@ -241,12 +241,12 @@ vfinfo (FILE *fp, const char *fmt, va_li
case 'S':
/* Print script file and linenumber. */
{
- node_type node;
+ etree_type node;
etree_type *tp = va_arg (arg, etree_type *);
if (tp == NULL)
{
- tp = (etree_type *) &node;
+ tp = &node;
tp->type.filename = ldlex_filename ();
tp->type.lineno = lineno;
}
brgds, H-P