Hi Martin,
> PR 78521 notes that the gimple-ssa-sprintf pass doesn't do the right
> thing (i.e., the -Wformat-length and -fprintf-return-value options
> behave incorrectly) when a conversion specification includes a width
> or precision with a non-constant value. The code treats such cases
> as if they were not provided which is incorrect and results in
> the wrong bytes counts in warning messages and in the wrong ranges
> being generated for such calls (or in the case sprintf(0, 0, ...)
> for some such calls being eliminated).
>
> The attached patch corrects the handling of these cases, plus a couple
> of other edge cases in the same area: it adjusts the parser to accept
> precision in the form of just a period with no asterisk or decimal
> digits after it (this sets the precision to zero), and corrects the
> handling of zero precision and zero argument in integer directives
> to produce no bytes on output.
>
> Finally, the patch also tightens up the constraint on the upper bound
> of bounded functions like snprintf to be INT_MAX. The functions cannot
> produce output in excess of INT_MAX + 1 bytes and some implementations
> (e.g., Solaris) fail with EINVAL when the bound is INT_MAX or more.
> This is the subject of PR 78520.
this patch broke Solaris bootstrap:
/vol/gcc/src/hg/trunk/local/gcc/gimple-ssa-sprintf.c: In function 'void
{anonymous}::get_width_and_precision(const {anonymous}::conversion_spec&, long
long int*, long long int*)':
/vol/gcc/src/hg/trunk/local/gcc/gimple-ssa-sprintf.c:777:45: error: call of
overloaded 'abs(long long int)' is ambiguous
width = abs (tree_to_shwi (spec.star_width));
^
/vol/gcc/src/hg/trunk/local/gcc/gimple-ssa-sprintf.c:777:45: note: candidates
are:
In file included from /usr/include/stdlib.h:12:0,
from /vol/gcc/src/hg/trunk/local/gcc/system.h:258,
from /vol/gcc/src/hg/trunk/local/gcc/gimple-ssa-sprintf.c:49:
/usr/include/iso/stdlib_iso.h:205:16: note: long int std::abs(long int)
inline long abs(long _l) { return labs(_l); }
^
/usr/include/iso/stdlib_iso.h:160:12: note: int std::abs(int)
extern int abs(int);
^
The following patch fixed this for me, but I've no idea if it's right.
It bootstrapped successfully on sparc-sun-solaris2.12,
i386-pc-solaris2.12, and x86_64-pc-linux-gnu.
Rainer
--
-----------------------------------------------------------------------------
Rainer Orth, Center for Biotechnology, Bielefeld University
2016-12-02 Rainer Orth <r...@cebitec.uni-bielefeld.de>
* gimple-ssa-sprintf.c (get_width_and_precision): Use std::abs.
diff --git a/gcc/gimple-ssa-sprintf.c b/gcc/gimple-ssa-sprintf.c
--- a/gcc/gimple-ssa-sprintf.c
+++ b/gcc/gimple-ssa-sprintf.c
@@ -774,7 +774,7 @@ get_width_and_precision (const conversio
if (spec.star_width)
{
if (TREE_CODE (spec.star_width) == INTEGER_CST)
- width = abs (tree_to_shwi (spec.star_width));
+ width = std::abs (tree_to_shwi (spec.star_width));
else
width = HOST_WIDE_INT_MIN;
}
