Home Original page

Fix presumed type clash in "ld

Fix presumed type clash in "ld - fix for bug 13343"

Hans-Peter Nilsson hans-peter.nilsson@axis.com
Sat Feb 18 04:20:00 GMT 2012 
> 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
More information about the Binutils mailing list