[MacPorts] #54638: mesa @17.1.6_0: error: implicit declaration of function 'fstatat' is invalid in C99

[MacPorts]

#54638: mesa @17.1.6_0: error: implicit declaration of function 'fstatat' is
invalid in C99
-------------------------+-------------------------------------------------
  Reporter:  tehcog      |      Owner:  jeremyhu
      Type:  defect      |     Status:  assigned
  Priority:  Normal      |  Milestone:
 Component:  ports       |    Version:  2.4.1
Resolution:              |   Keywords:  tiger leopard snowleopard lion
      Port:  mesa        |  mountainlion mavericks
-------------------------+-------------------------------------------------

Comment (by kencu):

 OK. This compiles without any particular issue. You need these added to
 `<sys/fcntl.h>`, possibly without the initial guard, but probably with the
 guard:
 {{{
 #if __DARWIN_C_LEVEL >= 200809L
 /*
  * Descriptor value for the current working directory
  */
 #define AT_FDCWD        -2

 /*
  * Flags for the at functions
  */
 #define AT_EACCESS              0x0010  /* Use effective ids in access
 check */
 #define AT_SYMLINK_NOFOLLOW     0x0020  /* Act on the symlink itself not
 the target */
 #define AT_SYMLINK_FOLLOW       0x0040  /* Act on target of symlink */
 #define AT_REMOVEDIR            0x0080  /* Path refers to directory */
 #endif
 }}}

 you need to add a definition for `getattrlistat` to avoid an implicit
 declaration error:
 {{{
 int getattrlistat(int dirfd, const char *pathname, struct attrlist *a,
                                  void *buf, size_t size, unsigned long
 flags);
 }}}
 and there is some secret sauce, info for which is found here
 <https://gist.github.com/bnoordhuis/4221344>
 {{{
 /* this is some apple internal magic */

 #include <sys/syscall.h>

 #ifndef SYS___pthread_chdir
 # define SYS___pthread_chdir 348
 #endif

 #ifndef SYS___pthread_fchdir
 # define SYS___pthread_fchdir 349
 #endif

 int __pthread_chdir(const char *path)
 {
   return syscall(SYS___pthread_chdir, path);
 }

 int __pthread_fchdir(int dirfd)
 {
   return syscall(SYS___pthread_fchdir, dirfd);
 }

 /* extern int __pthread_fchdir(int fd); */

 }}}

 and then it compiles through to an object file without any troubles, at
 least on this 10.6.8 system I like to use, with clang-3.9 and libc++.

 Perhaps Chris can help me come up with some test programs for it.

-- 
Ticket URL: <https://trac.macports.org/ticket/54638#comment:15>
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