Re: Behaviour differs at configure time

[Stepan Kasal]

Hello,

On Wed, Jul 20, 2005 at 10:02:18AM +0900, Andre Caldas wrote:
> Hello, All!
> 
> I have these lines in my configure.ac:
> 
> AC_CHECK_LIB( pthread, [pthread_create] )
> AC_CHECK_HEADERS( pthread.h, [ AC_DEFINE(THREAD_SAFE, 1,
>       [We will use posix threads]) ] )
> AC_CHECK_FUNCS( pthread_yield pthread_mutexattr_settype )
> 
> 
> I am cross-compiling (--host=arm-linux).
> 
> When I run the configure script it checks for 
> pthread_mutexattr_settype and finds it. But when I do a "make", I get 
> an error saying that this function is not defined.

configure uses some default headers.  Try this:

1) modify your configure.ac so that it looks for
        "pthread_mutexattr_settypeNO"
2) run autoconf && ./configure ...
   Of course, pthread_mutexattr_settypeNO is not found.
3) Look into the config.log: it says that pthread_mutexattr_settypeNO was
   not found and then there is an exact copy of the failed program.
   This is the same program which succeeded when configure found
   pthread_mutexattr_settype.  The gcc command line will also be somewhere
   near in config.log.
4) Try to compile that program with that cmdline.  It should succeed.
   Then you can investigate the differences.

HTH,
        Stepan Kasal