Message-ID: <5656CBA7.4060601@huawei.com>
Date: Thu, 26 Nov 2015 17:06:47 +0800
From: "Wangnan (F)" <wangnan0@huawei.com>
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0
MIME-Version: 1.0
To: =?UTF-8?B?5bmz5p2+6ZuF5bezIC8gSElSQU1BVFXvvIxNQVNBTUk=?= 
	<masami.hiramatsu.pt@hitachi.com>,
        "acme@kernel.org" <acme@kernel.org>
CC: "lizefan@huawei.com" <lizefan@huawei.com>,
        "pi3orama@163.com" <pi3orama@163.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Alexei Starovoitov <ast@kernel.org>,
        Arnaldo Carvalho de Melo <acme@redhat.com>,
        Namhyung Kim <namhyung@kernel.org>
Subject: Re: [PATCH 1/2] perf tools: Always give options even it not compiled
References: <20151117124224.GH22729@kernel.org> <1447941793-118639-1-git-send-email-wangnan0@huawei.com> <1447941793-118639-2-git-send-email-wangnan0@huawei.com> <50399556C9727B4D88A595C8584AAB3752627CD4@GSjpTKYDCembx32.service.hitachi.net> <5656BD42.5000703@huawei.com>
In-Reply-To: <5656BD42.5000703@huawei.com>
Content-Type: text/plain; charset="utf-8"; format=flowed
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 2489
Lines: 80


On 2015/11/26 16:05, Wangnan (F) wrote:
>
>
> On 2015/11/20 18:54, 平松雅巳 / HIRAMATU，MASAMI wrote:
>>> From: Wang Nan [mailto:wangnan0@huawei.com]
>>>
>>> This patch keeps options of perf builtins same in all condition. If the
>>> option is disabled because of compiling options, users should be
>>> notified.
>>>
>>> This patch does it by introducing a series of new option macros, flags
>>> and field in struct options. For those options disabled by compiling,
>>> OPT_NOTBUILT_NOARG, OPT_NOTBUILT_OPTARG and OPT_NOTBUILT can be used
>>> to record the help messages and the reason why not built them.
>>>
>>> Options in 'perf record' and 'perf probe' are fixed by those new 
>>> macros.
>> Hmm, OK, I agree the reason why this is useful. Could you reconsider
>> the implementation, because just cloning the code is ugly and not
>> maintainable?
>>
>> It will be better if we can replace OPT_BOOLEAN with;
>>
>>     OPT_DEPENDS(HAVE_DWARF_SUPPORT, BOOLEAN, '\0', "no-inlines", 
>> &probe_conf.no_inlines, ...
>>
>> This may be done by following macros ;
>>
>> ----
>> #define OPTMSG_HAVE_DWARF_SUPPORT "NO_DWARF"
>> #ifdef HAVE_DWARF_SUPPORT
>> #define OPTVAL_HAVE_DWARF_SUPPORT 1
>> #else
>> #define OPTVAL_HAVE_DWARF_SUPPORT 0
>> #endif
>>
>> #define __OPT_DEPENDS(val, msg, opt, ...)    \
>>     {.type = OPTION_NEXT_DEPENDS, .value = (void *)val, .data = msg, 
>> }, opt(__VA_ARGS__)
>>
>> #define _OPT_DEPENDS(val, msg, opt, ...)    \
>>     __OPT_DEPENDS(val, msg, opt, __VA_ARGS__)
>>
>> #define OPT_DEPENDS(flag, opt, ...)    \
>>     _OPT_DEPENDS(OPTVAL_ ## flag, OPTMSG_ ## flag, OPT_ ## opt, 
>> __VA_ARGS__)
>> ----
>>
>> And if the parser find OPTION_NEXT_DEPENDS and .value != NULL, it 
>> skips next entry.
>>
>
> That would be good, but don't forget we have a options__order() which
> reorder the options array. To archive our goal I think we must preprocess
> the options array to 'merge' information in the OPTION_NEXT_DEPENDS into
> the real option it decorates.
>

Doing such merging in parse_options_subcommand() is natually but require 
removing all
'const' decorators from struct options. Too much code changing for such 
a small
feature...

Will think another solution...

> Thank you.
>
>> Thank you,
>>
>


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/