From: Simon Marchi <simon.marchi@ericsson.com>
To: Alan Hayward <alan.hayward@arm.com>, <gdb-patches@sourceware.org>
Cc: <nd@arm.com>
Subject: Re: [PATCH v2 04/10] Add regcache raw_compare method
Date: Thu, 07 Jun 2018 20:56:00 -0000 [thread overview]
Message-ID: <ada727b3-a7d5-bc04-afd8-4b32f8ec67ac@ericsson.com> (raw)
In-Reply-To: <20180606151629.36602-5-alan.hayward@arm.com>
On 2018-06-06 11:16 AM, Alan Hayward wrote:
> raw_compare returns the same as a memcmp (0 for success,
> the diff otherwise). Kept with tristate return as this
> feels potentally more useful than a simple true/false return.
> (Happy to change if not).
I would err on the bool side, but I don't really mind, the important is
that it's documented properly. We still use many ints as bool in GDB, so
someone seeing an int return value could easily think it's 0 -> not equal,
1 -> equal.
Speaking of doc, I would suggest (as in the previous patch) to centralize
the doc in the class/struct at the root, so we don't duplicate it.
> 2018-06-06 Alan Hayward <alan.hayward@arm.com>
>
> gdb/
> * common/common-regcache.h (raw_compare): New function.
> * regcache.c (regcache::raw_compare): Likewise.
> * regcache.h (regcache::raw_compare): New declaration.
>
> gdbserver/
> * regcache.c (regcache::raw_compare): New function.
> * regcache.h (regcache::raw_compare): New declaration.
> ---
> gdb/common/common-regcache.h | 1 +
> gdb/gdbserver/regcache.c | 10 ++++++++++
> gdb/gdbserver/regcache.h | 5 +++++
> gdb/regcache.c | 15 +++++++++++++++
> gdb/regcache.h | 11 +++++++++++
> 5 files changed, 42 insertions(+)
>
> diff --git a/gdb/common/common-regcache.h b/gdb/common/common-regcache.h
> index 487da0a7fb..e91439bec5 100644
> --- a/gdb/common/common-regcache.h
> +++ b/gdb/common/common-regcache.h
> @@ -67,6 +67,7 @@ struct reg_buffer_common
> virtual ~reg_buffer_common () = default;
> virtual void raw_supply (int regnum, const void *buf) = 0;
> virtual void raw_collect (int regnum, void *buf) const = 0;
> + virtual int raw_compare (int regnum, const void *buf, int offset) const = 0;
> virtual register_status get_register_status (int regnum) const = 0;
> };
>
> diff --git a/gdb/gdbserver/regcache.c b/gdb/gdbserver/regcache.c
> index 857721ee3d..9648428349 100644
> --- a/gdb/gdbserver/regcache.c
> +++ b/gdb/gdbserver/regcache.c
> @@ -501,3 +501,13 @@ regcache::get_register_status (int regnum) const
> return REG_VALID;
> #endif
> }
> +
> +/* See gdbserver/regcache.h. */
> +
> +int
> +regcache::raw_compare (int regnum, const void *buf, int offset) const
> +{
> + gdb_assert (register_size (tdesc, regnum) > offset);
Should we check ">= offset"? I think it could be useful for some edge cases
where we could avoid an "if (offset < size)" in the caller, if we know offset
could be equal to size. memcmp would return 0 (equal), which is fine.
Maybe assign "register_size (tdesc, regnum)" to a variable (e.g. reg_size)
and use it in both places?
> + return memcmp (buf, register_data (this, regnum, 1) + offset,
> + register_size (tdesc, regnum) - offset);
> +}
> diff --git a/gdb/gdbserver/regcache.h b/gdb/gdbserver/regcache.h
> index 1842f1d9cf..b26f39a8ad 100644
> --- a/gdb/gdbserver/regcache.h
> +++ b/gdb/gdbserver/regcache.h
> @@ -50,6 +50,11 @@ struct regcache : public reg_buffer_common
>
> void raw_collect (int regnum, void *buf) const override;
>
> + /* Compare the contents of the register stored in the regcache (ignoring the
> + first OFFSET bytes) to the contents of BUF (without any offset). Returns
> + the same result as memcmp. */
> + int raw_compare (int regnum, const void *buf, int offset) const override;
> +
> enum register_status get_register_status (int regnum) const override;
> };
>
> diff --git a/gdb/regcache.c b/gdb/regcache.c
> index a914b548ca..383e355e9f 100644
> --- a/gdb/regcache.c
> +++ b/gdb/regcache.c
> @@ -1082,6 +1082,21 @@ regcache::collect_regset (const struct regset *regset,
> transfer_regset (regset, NULL, regnum, NULL, buf, size);
> }
>
> +/* See regcache.h. */
> +
> +int
> +regcache::raw_compare (int regnum, const void *buf, int offset) const
> +{
> + const char *regbuf;
> + size_t size;
> +
> + gdb_assert (buf != NULL);
> + assert_regnum (regnum);
Should we assert that offset is < or <= size here too?
Simon
next prev parent reply other threads:[~2018-06-07 20:56 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-06 15:16 [PATCH v2 00/10] gdb/gdbserver support for aarch64 SVE Alan Hayward
2018-06-06 15:17 ` [PATCH v2 04/10] Add regcache raw_compare method Alan Hayward
2018-06-07 20:56 ` Simon Marchi [this message]
2018-06-08 15:16 ` Alan Hayward
2018-06-10 22:26 ` Simon Marchi
2018-06-06 15:17 ` [PATCH v2 03/10] Add reg_buffer_common Alan Hayward
2018-06-07 20:19 ` Simon Marchi
2018-06-07 20:42 ` Simon Marchi
2018-06-08 14:14 ` Alan Hayward
2018-06-10 22:21 ` Simon Marchi
2018-06-06 15:17 ` [PATCH v2 06/10] Add Aarch64 SVE dwarf regnums Alan Hayward
2018-06-11 0:43 ` Simon Marchi
2018-06-06 15:17 ` [PATCH v2 05/10] Ptrace support for Aarch64 SVE Alan Hayward
2018-06-10 22:52 ` Simon Marchi
2018-06-06 15:17 ` [PATCH v2 10/10] Remove reg2 section from Aarch64 SVE cores Alan Hayward
2018-06-11 2:47 ` Simon Marchi
2018-06-11 16:37 ` Alan Hayward
2018-06-06 15:17 ` [PATCH v2 08/10] Enable Aarch64 SVE for gdbserver Alan Hayward
2018-06-11 0:49 ` Simon Marchi
2018-06-06 15:17 ` [PATCH v2 07/10] Increase gdbsever PBUFSIZ Alan Hayward
2018-06-11 0:46 ` Simon Marchi
2018-06-06 15:17 ` [PATCH v2 01/10] Aarch64 SVE pseudo register support Alan Hayward
2018-06-06 22:17 ` Simon Marchi
2018-06-07 9:34 ` Alan Hayward
2018-06-06 15:17 ` [PATCH v2 09/10] Ptrace support for AArch64 SVE gdbsever Alan Hayward
2018-06-11 2:43 ` Simon Marchi
2018-06-11 2:44 ` Simon Marchi
2018-06-06 15:17 ` [PATCH v2 02/10] Add Aarch64 SVE Linux headers Alan Hayward
2018-06-08 14:13 ` Alan Hayward
2018-06-08 14:37 ` Simon Marchi
2018-06-08 15:23 ` Simon Marchi
2018-06-12 14:37 ` Alan Hayward
2018-06-12 14:43 ` Pedro Alves
2018-06-12 15:06 ` Simon Marchi
2018-06-12 15:11 ` Pedro Alves
2018-06-12 15:21 ` Simon Marchi
2018-06-12 15:09 ` Alan Hayward
2018-06-12 14:51 ` Simon Marchi
2018-06-12 16:34 ` Sergio Durigan Junior
2018-06-12 17:51 ` Alan Hayward
2018-06-12 20:29 ` Sergio Durigan Junior
2018-06-15 9:45 ` Ramana Radhakrishnan
2018-06-15 17:14 ` Alan Hayward
2018-09-20 21:16 ` Status of the AArch* builders (was: Re: [PATCH v2 02/10] Add Aarch64 SVE Linux headers) Sergio Durigan Junior
2018-09-24 14:16 ` Alan Hayward
2018-09-24 14:42 ` Status of the AArch* builders Sergio Durigan Junior
2018-10-11 9:23 ` Alan Hayward
2018-10-12 19:06 ` Sergio Durigan Junior
2018-10-15 10:16 ` Alan Hayward
2018-10-15 12:42 ` Sergio Durigan Junior
2018-10-15 14:02 ` Alan Hayward
2018-10-15 15:32 ` Sergio Durigan Junior
2018-10-17 18:46 ` Sergio Durigan Junior
2018-10-24 9:56 ` Alan Hayward
2018-10-25 16:26 ` Sergio Durigan Junior
2018-06-08 15:27 ` [PATCH v2 02/10] Add Aarch64 SVE Linux headers Alan Hayward
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