From mboxrd@z Thu Jan 1 00:00:00 1970 From: julia.lawall@lip6.fr (Julia Lawall) Date: Wed, 17 Oct 2018 14:26:10 +0200 (CEST) Subject: [Cocci] __asm statements confuse spatch In-Reply-To: <6ad4f5bb-9aee-d243-46ef-36ec5a5e6508@kernel.org> References: <6ad4f5bb-9aee-d243-46ef-36ec5a5e6508@kernel.org> Message-ID: To: cocci@systeme.lip6.fr List-Id: cocci@systeme.lip6.fr On Wed, 17 Oct 2018, Timur Tabi wrote: > On 10/17/18 12:25 AM, Julia Lawall wrote: > > Linux uses __asm__ ( ... ), which is what Coccinelle recognizes. I can > > probably add _asm and __asm with the braces. On the other hand, the > > second case, with no delimiter seems awkward. Does that occur a lot? > > Basically it's not clear how to parse it. I could have __asm eat up > > everything until the end of the line, but then the third case won't work. > > Well, it doesn't occur *a lot*, since it's only one set of files that has this > problem for me. I believe this code isn't compiled with gcc, which is why the > syntax is non-standard. > > I don't know if it's worth updating spatch for it. For now, I just manually > comment-out the offending code in the C file and then run spatch. > > > > Another problem I've having with the source file is that it has > > > inconsistent usage of braces, and sometimes spatch wants to add > > > unnecessary braces that look off. For example, this: > > > > > > if (...) > > > DBG_PRINTF((...)); > > > else > > > DBG_PRINTF((...)); > > > } > > > > > > (the } belongs to some if-statement much earlier in code somewhere) > > > becomes: > > > > > > if (...) { > > > NV_PRINTF(...); > > > } > > > else { > > > NV_PRINTF(...); > > > } > > > } > > > > > > I really don't want spatch to add the braces. > > > I don't think this has anything to do with the trailing }. > > Sorry, I didn't mean to imply that it does. My point was that the trailing } > is in an awkward position already, and when spatch adds its own brace, the > result looks weird. > > > Coccinelle > > knows which brace goes with what, independent of the indentation. > > Something about your rule is making it unsure whether the changed code is > > in a branch by itself, or whether you have added multiple statements. > > > > For example, if your rule is > > > > - A; > > + B; > > + C; > > Hmmm.... I run some tests with my script to see if anything stands out, but > the whole purpose of my script is to replace DBG_PRINTF with NV_PRINTF. I > never add a second line. > > > and the code is if (x) A;, then the braces are needed. Spatch is a bit > > conservative about this, ie it adds brace unless it is clear that there is > > a replacement of a single statement by another one. > > > > You could try to track down the problem by making a minimal semantic > > patch and C code that show the problem, or just add some rules to clean > > up afterwards. > > What would a clean-up rule look like? Something like this? > > -{ > NV_PRINTF2(...) > -} That is missing a ; but with that it should be OK. In the Linux kernel, if one branch has {} the other should too, so if you want to respect that rule, then you would need various cases for various configurations of if. julia