Re: [PATCH] have -Wformat-overflow handle -fexec-charset (PR 80503)

[Renlin Li <renlin dot li at foss dot arm dot com>]

Hi Martin,

I did a little investigation into this. Please correct me if I missed anything.

I build a native arm-linux-gnueabihf toolchain in armhf hardware.
It's ILP32. So in this situation:

HOST_WIDE_INT is long, which is 32-bit.
integer type 32-bit as well, so target_int_max () == LONG_MAX


gimple-ssa-sprintf.c line 2887
>   /* Has the likely and maximum directive output exceeded INT_MAX?  */
>   bool likelyximax = *dir.beg && res->range.likely > target_int_max ();

likelyximax will be false as the latter expression is always false.
res->range.likely is truncated to LONG_MAX (in target_strtol10 function)

I have checked in cross build environment (host x86_64), this variable is true.

Regards,
Renlin


On 13/06/17 09:16, Renlin Li wrote:
> Hi Martin,
>
> On 04/06/17 23:24, Martin Sebor wrote:
> > On 06/02/2017 09:38 AM, Renlin Li wrote:
> > > Hi Martin,
> > >
> > > After r247444, I saw the following two regressions in
> > > arm-linux-gnueabihf environment:
> > >
> > > FAIL: gcc.dg/tree-ssa/builtin-sprintf-warn-18.c  (test for warnings,
> > > line 119)
> > > PASS: gcc.dg/tree-ssa/builtin-sprintf-warn-18.c  (test for warnings,
> > > line 121)
> > > FAIL: gcc.dg/tree-ssa/builtin-sprintf-warn-18.c  (test for warnings,
> > > line 121)
> > >
> > > The warning message related to those two lines are:
> > > testsuite/gcc.dg/tree-ssa/builtin-sprintf-warn-18.c:119:3: warning:
> > > '%9223372036854775808i' directive width out of range [-Wformat-overflow=]
> > >
> > > testsuite/gcc.dg/tree-ssa/builtin-sprintf-warn-18.c:121:3: warning:
> > > '%.9223372036854775808i' directive precision out of range
> > > [-Wformat-overflow=]
> > >
> > > testsuite/gcc.dg/tree-ssa/builtin-sprintf-warn-18.c:121:3: warning:
> > > '%.9223372036854775808i' directive precision out of range
> > > [-Wformat-overflow=]
> > >
> > > Did you notice similar things from your test environment, Christophe?
> >
> > Looks like you're missing a couple of warnings.  I see the following
> > output with both my arm-linux-gnueabihf cross compiler and my native
> > x86_64 GCC, both in 32-bit and 64-bit modes, as expected by the test,
> > so I don't see the same issue in my environment.
>
> Yes, it happens on arm-linux-gnueabihf native environment. the warnings with "INT_MAX"
> line are missing. I don't know if the host environment will cause the difference.
>
> Regards,
> Renlin
>
> > /ssd/src/gcc/git/gcc/testsuite/gcc.dg/tree-ssa/builtin-sprintf-warn-18.c:119:3: warning:
> > ‘%9223372036854775808i’ directive width out of range [-Wformat-overflow=]
> >     T ("%9223372036854775808i", 0);    /* { dg-warning "width out of range" } */
> >     ^
> > /ssd/src/gcc/git/gcc/testsuite/gcc.dg/tree-ssa/builtin-sprintf-warn-18.c:119:3: warning:
> > ‘%9223372036854775808i’ directive output of 9223372036854775807 bytes causes result to
> > exceed ‘INT_MAX’ [-Wformat-overflow=]
> > /ssd/src/gcc/git/gcc/testsuite/gcc.dg/tree-ssa/builtin-sprintf-warn-18.c:121:3: warning:
> > ‘%.9223372036854775808i’ directive precision out of range [-Wformat-overflow=]
> >     T ("%.9223372036854775808i", 0);   /* { dg-warning "precision out of range" } */
> >     ^
> > /ssd/src/gcc/git/gcc/testsuite/gcc.dg/tree-ssa/builtin-sprintf-warn-18.c:121:3: warning:
> > ‘%.9223372036854775808i’ directive output of 9223372036854775807 bytes causes result to
> > exceed ‘INT_MAX’ [-Wformat-overflow=]
> >
> > Martin