[Cocci] Replacing one (specific!) type with another

[Nikolaus@rath.org (Nikolaus Rath)]

On Oct 10 2016, Julia Lawall <julia.lawall@lip6.fr> wrote:
>> Ok, we're getting there. I've removed the second 'symbol' line, and
>> (permanently) updated to 1.0.6. However, now it seems to simply run
>> forever:
>>
>> $ ../coccinelle-1.0.6/spatch.opt --sp-file
>> ~/in-progress/libfuse/se-rename.cocci --in-place lib/ include/ test/
>> example/ util/
>> init_defs_builtins: /home/nikratio/tmp/coccinelle-1.0.6/standard.h
>> warning: patch output can only be created when only one
>> directory is specified or when the -patch flag is used
>> HANDLING: lib/fuse.c
>> (ONCE) Expected tokens fuse_session f
>> Skipping:lib/fuse_opt.c
>> HANDLING: lib/helper.c
>> Skipping:lib/mount_bsd.c
>> Skipping:lib/fuse_loop_mt.c
>> Skipping:lib/fuse_loop.c
>> HANDLING: lib/cuse_lowlevel.c
>> diff =
>> [...]
>> HANDLING: lib/fuse_lowlevel.c
>>
>> At this point it has been hanging for about 15 minutes now, steady
>> eating CPU time.
>>
>> Is it supposed to take that long? The fuse_lowlevel.c file is 74k with
>> 2465 lines of code.
>
> You can use --show-trying to see what function it is getting stuck on.  If
> the function has a lot of ifs and loops, it may indeed take a long
> time.  ... follows possible paths in the execution graph and a sequence of
> ifs makes the number of paths grow exponentially.
>
> A solution is to add a timeout, eg --timeout 120 (120 seconds).  You will
> need to check a file on which there is a timeout manually.
>
> Tracing paths around loops is not really relevant in your case, so you can
> also safely use the option --no-loops, which will avoid taking the back
> edges.
 
I tried doing both, but it still gets stuck:

init_defs_builtins: /home/nikratio/tmp/coccinelle-1.0.6/standard.h
HANDLING: lib/fuse_lowlevel.c
-----------------------------------------------------------------------
rule starting on line 1 = 
-----------------------------------------------------------------------
[...]
-----------------------------------------------------------------------
rule starting on line 13 = 
-----------------------------------------------------------------------
[...]
   trying function: do_init: fuse_lowlevel.c:1812


The do_init() function doesn't seem all that terrible to me though:
https://github.com/libfuse/libfuse/blob/58273972f0b20/lib/fuse_lowlevel.c#L1812

Best,
-Nikolaus
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