From: Joel Brobecker <brobecker@adacore.com>
To: Tom Tromey <tromey@adacore.com>
Cc: gdb-patches@sourceware.org
Subject: Re: [PATCH] Handle fixed-point division by zero
Date: Sun, 13 Dec 2020 18:01:36 +0400 [thread overview]
Message-ID: <20201213140136.GH366101@adacore.com> (raw)
In-Reply-To: <20201211151548.732285-1-tromey@adacore.com>
Hi Tom,
On Fri, Dec 11, 2020 at 08:15:48AM -0700, Tom Tromey wrote:
> fixed_point_binop did not account for division by zero. This would
> lead to gdb getting SIGFPE and subsequently cause some test cases to
> hang.
>
> gdb/ChangeLog
> 2020-12-11 Tom Tromey <tromey@adacore.com>
>
> * valarith.c (fixed_point_binop): Call error on division by zero.
>
> gdb/testsuite/ChangeLog
> 2020-12-11 Tom Tromey <tromey@adacore.com>
>
> * gdb.dwarf2/dw2-fixed-point.exp: Add test for division by zero.
Thanks for the patch. It looks good to me.
(sooo obvious in hindsight...)
> ---
> gdb/ChangeLog | 4 ++++
> gdb/testsuite/ChangeLog | 4 ++++
> gdb/testsuite/gdb.dwarf2/dw2-fixed-point.exp | 3 +++
> gdb/valarith.c | 2 ++
> 4 files changed, 13 insertions(+)
>
> diff --git a/gdb/testsuite/gdb.dwarf2/dw2-fixed-point.exp b/gdb/testsuite/gdb.dwarf2/dw2-fixed-point.exp
> index 67d1d34d8f3..2c859d1fd16 100644
> --- a/gdb/testsuite/gdb.dwarf2/dw2-fixed-point.exp
> +++ b/gdb/testsuite/gdb.dwarf2/dw2-fixed-point.exp
> @@ -164,6 +164,9 @@ gdb_test "print pck.fp3_var * 1" \
> gdb_test "print pck.fp3_var / pck.fp3_var" \
> " = 1"
>
> +gdb_test "print pck.fp3_var / 0" \
> + "Division by zero"
> +
> gdb_test "print pck.fp1_range_var - 0.5" \
> " = 0.5"
>
> diff --git a/gdb/valarith.c b/gdb/valarith.c
> index 37988f1dfa7..6854d9b80f0 100644
> --- a/gdb/valarith.c
> +++ b/gdb/valarith.c
> @@ -965,6 +965,8 @@ fixed_point_binop (struct value *arg1, struct value *arg2, enum exp_opcode op)
> break;
>
> case BINOP_DIV:
> + if (mpq_sgn (v2.val) == 0)
> + error (_("Division by zero"));
> mpq_div (res.val, v1.val, v2.val);
> val = fixed_point_to_value (res);
> break;
> --
> 2.26.2
--
Joel
prev parent reply other threads:[~2020-12-13 14:01 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-11 15:15 Tom Tromey
2020-12-13 14:01 ` Joel Brobecker [this message]
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