[ccan] [PATCH 3/3] memfuncs: Implement memrchr()

[Rusty Russell]

Rusty Russell <rusty at rustcorp.com.au> writes:
> David Gibson <david at gibson.dropbear.id.au> writes:
>> On Sun, Oct 19, 2014 at 05:00:45PM +0300, Ran Benita wrote:
>>> On Sun, Oct 19, 2014 at 02:07:46PM +0200, David Gibson wrote:
>>> > The memrchr() function, which works like memchr(), but searches from the
>>> > back of the region to the front is implemented in the GNU C library, but
>>> > isn't standard.
>>> > 
>>> > This patch adds an implementation of the function to the memfuncs module,
>>> > when it's not available in the system C library.
>>> > 
>>> > Signed-off-by: David Gibson <david at gibson.dropbear.id.au>
>>> > ---
>>> >  ccan/memfuncs/memfuncs.c          | 14 ++++++++++++++
>>> >  ccan/memfuncs/memfuncs.h          |  4 ++++
>>> >  ccan/memfuncs/test/run.c          | 16 +++++++++++++++-
>>> >  tools/configurator/configurator.c |  6 ++++++
>>> >  4 files changed, 39 insertions(+), 1 deletion(-)
>>> > 
>>> > diff --git a/ccan/memfuncs/memfuncs.c b/ccan/memfuncs/memfuncs.c
>>> > index c80b862..2674f41 100644
>>> > --- a/ccan/memfuncs/memfuncs.c
>>> > +++ b/ccan/memfuncs/memfuncs.c
>>> > @@ -25,3 +25,17 @@ void *memmem(const void *haystack, size_t haystacklen,
>>> >  	return NULL;
>>> >  }
>>> >  #endif
>>> > +
>>> > +#if !HAVE_MEMRCHR
>>> > +void *memrchr(const void *s, int c, size_t n)
>>> > +{
>>> > +	unsigned char *p = (unsigned char *)s;
>>> > +	size_t i;
>>> 
>>> This needs to be ssize_t, otherwise the loop doesn't end.
>>
>> Good point.  More importantly, the fact that my testcases did
>> terminate indicates that they're not actually testing the local
>> implementations :(.
>
> Yes, that's weird.  ccanlint's "tests_pass_without_features" *should*
> have caught this.
>
> Let me check...
> Rusty.

Ah, fascinating.  You got the builtin memrchr because your run.c
included the header only, not the .c file.

You could rename run.c to api.c, or "#include <ccan/memfuncs/memfuncs.c>"
instead of "#include <ccan/memfuncs/memfuncs.h>".

Cheers,
Rusty.