On 02/24/2017 03:10 AM, Richard Biener wrote:
On Fri, Feb 24, 2017 at 1:35 AM, Martin Sebor <mse...@gmail.com> wrote:
Bug 79691 - -Wformat-truncation suppressed by (and only by) -Og
points out that the gimple-ssa-sprintf pass doesn't run when
this optimization option is used. That's because I forgot to
add it to the set of optimization passes that run with that
option. The attached trivial patch tested on x86_64 corrects
the oversight.
Is this okay for 7.0?
Any reason for the placement before copy-prop? I'd have done it
after pass_late_warn_uninitialized for example.
I wanted to make sure that folded sprintf return values would be
eligible for further copy propagation. E.g., that a + b would
be folded into a constant:
int foo (void)
{
int a = snprintf (0, 0, "%i", 123);
int b = snprintf (0, 0, "%i", 1234);
return a + b;
}
But I could have easily missed some important use case where this
placement will compromise the warning. I don't have any tests
for this one way or the other so I'm happy to go with your
recommendation. Let me know which you think is more appropriate
(if you have a suggestion for a test case I'd be grateful).
Also doesn't pass_sprintf_length rely on get_range_info ()? With -Og
nothing populates those so you'll always get effectively VARYING ranges.
It does when it's available but as Jakub noted, it works without
it as well (at -O0).
Thanks
Martin
