On 04/26/2016 07:08 AM, Jakub Jelinek wrote:
Hi!
I've noticed a warning during bootstrap:
../../gcc/reorg.c: In function ‘void try_merge_delay_insns(rtx_insn*,
rtx_insn*)’:
../../gcc/reorg.c:1431:12: warning: name lookup of ‘i’ changed
for (i = 0; i < XVECLEN (PATTERN (insn), 0); i++)
^
../../gcc/reorg.c:1263:7: warning: matches this ‘i’ under ISO standard rules
int i, j;
^
../../gcc/reorg.c:1413:25: warning: matches this ‘i’ under old rules
for (unsigned int i = len - 1; i < len; i--)
^
It is not fatal, but still ugly. The problem is that the function has
int i;
...
for (i = 0; ...)
...
for (unsigned int i = ... )
...
for (i = 0; ...)
This patch just declares the var in the only affected loop, so that the warning
is not emitted, unless we start checking -Wshadow warnings, I think this is
good enough.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2016-04-26 Jakub Jelinek <ja...@redhat.com>
* reorg.c (try_merge_delay_insns): Declare i inside the last
for loop to avoid warning.
I'd like to declare this in the "obviously OK" category for future
changes of a similar nature. But I don't think we can because in the
general case the value from the loop may be used outside the loop.
Makes me wonder if a plugin could help identify the obvious cases where
the value from the loop isn't used outside the loop, thus allowing
someone to quickly convert many of these things with a small effort.
jeff
