Re: [PATCH] gdb/i387-tdep.c: Avoid warning for "-Werror=strict-overflow"

Mark Kettenis
2014-10-03T15:46:57Z

>
> gdb requires "-Werror", and I387_ST0_REGNUM (tdep) is 'variable', then
> compiler can think that I387_ST0_REGNUM (tdep) may be a large number,
> which may cause issue, so report warning.

Sorry, but obfuscating code to make compilers happy is *not* the way to go.

> 2014-10-03 Chen Gang <gang.chen.5i5j@gmail.com>
>
> *i387-tdep.c (i387_supply_fsave): Avoid warning for
> "-Werror=strict-overflow"
> ---
> gdb/i387-tdep.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/gdb/i387-tdep.c b/gdb/i387-tdep.c
> index d66ac6a..c89e647 100644
> --- a/gdb/i387-tdep.c
> +++ b/gdb/i387-tdep.c
> @@ -454,7 +454,7 @@ i387_supply_fsave (struct regcache *regcache, int regnum, const void *fsave)
>
> gdb_assert (tdep->st0_regnum >= I386_ST0_REGNUM);
>
> - for (i = I387_ST0_REGNUM (tdep); i < I387_XMM0_REGNUM (tdep); i++)
> + for (i = I387_ST0_REGNUM (tdep); I387_XMM0_REGNUM (tdep) - i > 0; i++)
> if (regnum == -1 || regnum == i)
> {
> if (fsave == NULL)
> @@ -507,7 +507,7 @@ i387_collect_fsave (const struct regcache *regcache, int regnum, void *fsave)
>
> gdb_assert (tdep->st0_regnum >= I386_ST0_REGNUM);
>
> - for (i = I387_ST0_REGNUM (tdep); i < I387_XMM0_REGNUM (tdep); i++)
> + for (i = I387_ST0_REGNUM (tdep); I387_XMM0_REGNUM (tdep) - i > 0; i++)
> if (regnum == -1 || regnum == i)
> {
> /* Most of the FPU control registers occupy only 16 bits in
> --
> 1.8.5.2 (Apple Git-48)
>