On 06/20/14 13:01, Jakub Jelinek wrote:
On Fri, Jun 20, 2014 at 07:36:41PM +0200, Marek Polacek wrote:
2014-06-20 Marek Polacek <pola...@redhat.com>
* genpreds.c (verify_rtx_codes): New function.
(main): Call it.
* rtl.h (RTX_FLD_WIDTH, RTX_HWINT_WIDTH): Define.
(struct rtx_def): Use them.
Note, e.g. Coverity also complains about this stuff loudly too,
Yes it does. IIRC, these warnings from Coverity were the cause of GCC
reaching the #1 or #2 position across Red Hat's packages in terms of
Coverity warnings. Not a good position to be in.
like spot. Most RTLs are allocated through rtx_alloc and the size
is determined from RTX_HDR_SIZE (i.e. offsetof) and/or RTX_CODE_SIZE,
so your rtl.h change IMHO shouldn't affect anything but make the
expmed.c init_expmed_rtl structure somewhat longer.
Right. This comment was actually very helpful in that I wasn't aware of
precisely which cases Marek was trying to address.
Presumably the [1] sizing is what prevents any compile-time checking of
this?
No strong opinion on the internal_error vs error+unreachable.
--- gcc/genpreds.c
+++ gcc/genpreds.c
@@ -1471,6 +1471,40 @@ parse_option (const char *opt)
return 0;
}
+/* Verify RTX codes. We can't call fatal_error here, so call
+ gcc_unreachable after error to really abort. */
+
+static void
+verify_rtx_codes (void)
+{
+ unsigned int i, j;
+
+ for (i = 0; i < NUM_RTX_CODE; i++)
+ if (strchr (GET_RTX_FORMAT (i), 'w') == NULL)
+ {
+ if (strlen (GET_RTX_FORMAT (i)) > RTX_FLD_WIDTH)
+ {
+ error ("insufficient size of RTX_FLD_WIDTH");
+ gcc_unreachable ();
I think it would be nice to be more verbose, i.e. say
which rtx has longer format string than RTX_FLD_WIDTH, and perhaps also
the size and RTX_FLD_WIDTH value. Also, can't you use internal_error
instead of error + gcc_unreachable ?
Agreed, definitely indicate which RTX code is problematical.
Jeff
