From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <4BCC9247.10709@domain.hid> Date: Mon, 19 Apr 2010 19:26:31 +0200 From: Gilles Chanteperdrix MIME-Version: 1.0 References: <4BCC619E.2@domain.hid> <4BCC6CEE.70907@domain.hid> <4BCC6E3C.3090301@domain.hid> <4BCC7092.1030809@domain.hid> <4BCC71AF.4030903@domain.hid> <4BCC77BD.9040900@domain.hid> <4BCC78D5.3010405@domain.hid> <4BCC7D88.4070403@domain.hid> <1271693411.16659.128.camel@domain.hid> <4BCC814C.6050003@domain.hid> <4BCC8484.1020108@domain.hid> <4BCC9107.1080605@domain.hid> In-Reply-To: <4BCC9107.1080605@domain.hid> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai-core] [RFC] fix XENO_OPT_DEBUG bugs. List-Id: Xenomai life and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jan Kiszka Cc: xenomai-core Jan Kiszka wrote: > Gilles Chanteperdrix wrote: >> Jan Kiszka wrote: >>> Philippe Gerum wrote: >>>>>>> config XENO_OPT_DEBUG_FOO >>>>>>> bool "..." >>>>>>> >>>>>>> config XENO_OPT_DEBUG_FOO_P >>>>>>> int >>>>>>> default "1" if XENO_OPT_DEBUG_FOO >>>>>>> default "0" >>>>>>> >>>>>>> and XENO_DEBUG() could be extended to test for >>>>>>> CONFIG_XENO_OPT_DEBUG_FOO_P when given "FOO". I'm just not sure if this >>>>>>> can be expressed for legacy 2.4 kernels, so it might have to wait for >>>>>>> Xenomai 3. >>>> Well, actually, I would not merge this in Xenomai 3. I find this rather >>>> overkill; mainline first I mean, and mainline, i.e. the Xenomai code >>>> base only requires a simple and straightforward way to get debug >>>> switches right. Having to make Kconfig a kitchen sink for some unknown >>>> out of tree modules to be happy is not really my preferred approach in >>>> this particular case. >>>> >>>> Don't get me wrong, I'm not opposed to a more decentralized approach on >>>> the paper, it's just that I only care about the mainline tree here. >>> The point is not out-of-tree but robustness. Neither the current >>> decentralized #ifdef-#define nor its centralized brother meet this >>> criteria. An approach like the above which forces you to provide all >>> required bits before any of the cases (disabled/enabled) starts to work >>> does so. >> Ok. What about: >> >> #define __name2(a, b) a ## b >> #define name2(a, b) __name2(a, b) >> >> #define DECLARE_ASSERT_SYMBOL(sym) \ >> static const int CONFIG_XENO_OPT_DEBUG_##sym##0 = 0, \ >> __CONFIG_XENO_OPT_DEBUG_##sym = name2(CONFIG_XENO_OPT_DEBUG_##sym, 0) >> >> #define XENO_ASSERT(subsystem,cond,action) do { \ >> if (unlikely(__CONFIG_XENO_OPT_DEBUG_##subsystem > 0 && !(cond))) { \ >> xnarch_trace_panic_freeze(); \ >> xnlogerr("assertion failed at %s:%d (%s)\n", __FILE__, __LINE__, (#cond)); \ >> xnarch_trace_panic_dump(); \ >> action; \ >> } \ >> } while(0) >> >> DECLARE_ASSERT_SYMBOL(NUCLEUS); >> >> It fails to compile when the debug symbol is set and >> DECLARE_ASSERT_SYMBOL is missing, which plugs the failure of my previous >> attempt. > > I'm still wrapping my head around this. What would be the usage, > > #ifndef CONFIG_XENO_OPT_DEBUG_FOO > #define CONFIG_XENO_OPT_DEBUG_FOO 0 > #endif > > DECLARE_ASSERT_SYMBOL(FOO); > > ? If the compiler is smart enough to still drop the asserts based on > static const, I'm fine as this is an improvement. No, you just use DECLARE_ASSERT_SYMBOL(FOO) > > Still, IMHO, this solution would not even win the second league beauty > contest (now it comes with as many additional lines as the > Kconfig-approach). Yes, it is not pretty but to add a config option you just add the usual Kconfig stuff, then DECLARE_ASSERT_SYMBOL in the code instead of the #ifndef #define foo 0 #endif. If you do not do it, you get a compilation error whether the option is enabled or not. It can be decentralized, the find | grep mentioned earlier will still work. -- Gilles.