Re: [PATCH v2 06/25] util: Add CRC16 (CCITT) calculation routines

[Philippe Mathieu-Daudé]

On 1/24/21 9:07 PM, Richard Henderson wrote:
> On 1/24/21 8:59 AM, Philippe Mathieu-Daudé wrote:
>> On 1/23/21 11:39 AM, Bin Meng wrote:
>>> From: Bin Meng <bin.meng@windriver.com>
>>>
>>> Import CRC16 calculation routines from Linux kernel v5.10:
>>>
>>>   include/linux/crc-ccitt.h
>>>   lib/crc-ccitt.c
>>>
>>> to QEMU:
>>>
>>>   include/qemu/crc-ccitt.h
>>>   util/crc-ccitt.c
>>>
>>> Signed-off-by: Bin Meng <bin.meng@windriver.com>
>>> Acked-by: Alistair Francis <alistair.francis@wdc.com>
>>> ---
>>>
>>> (no changes since v1)
>>>
>>>  include/qemu/crc-ccitt.h |  33 ++++++++++
>>>  util/crc-ccitt.c         | 127 +++++++++++++++++++++++++++++++++++++++
>>>  util/meson.build         |   1 +
>>>  3 files changed, 161 insertions(+)
>>>  create mode 100644 include/qemu/crc-ccitt.h
>>>  create mode 100644 util/crc-ccitt.c
>> ...
>>
>>> diff --git a/util/meson.build b/util/meson.build
>>> index 540a605b78..05a376ae02 100644
>>> --- a/util/meson.build
>>> +++ b/util/meson.build
>>> @@ -29,6 +29,7 @@ util_ss.add(files('qemu-config.c', 'notify.c'))
>>>  util_ss.add(files('qemu-option.c', 'qemu-progress.c'))
>>>  util_ss.add(files('keyval.c'))
>>>  util_ss.add(files('crc32c.c'))
>>> +util_ss.add(files('crc-ccitt.c'))
>>
>> OK but we can restrict this to system-mode emulation, as user-mode
>> and tools don't require it.
> 
> Doesn't this get put in libutil, where it is only pulled from the archive when
> needed?  Also, libutil is built once, not per-target.

Hmm I just sent a pull request with this change squashed in.
Should I cancel it?

My view is we don't install libqemuutil.a anywhere, so why overload
building unused objects when some configuration don't need it?

Some of the configurations I test:
- build tools only
- build linux-user only

dbus.o and yank.o are also restricted to have_system.
various objects are restricted to have_block (which is
have_system or have_tools).