[PATCH 6/6] Add configure check for members of dirent for use in io/readdir.c

[Felix Janda]

Dave Chinner wrote:
> On Tue, Jan 12, 2016 at 09:00:22PM +0100, Felix Janda wrote:
> > Signed-off-by: Felix Janda <felix.janda at posteo.de>
> > ---
> >  configure.ac         |  7 +++++++
> >  include/builddefs.in |  4 ++++
> >  io/Makefile          | 10 ++++++++++
> >  3 files changed, 21 insertions(+)
> > 
> > diff --git a/configure.ac b/configure.ac
> > index feee50a..3d6443a 100644
> > --- a/configure.ac
> > +++ b/configure.ac
> > @@ -135,5 +135,12 @@ AC_CHECK_SIZEOF([char *])
> >  AC_TYPE_UMODE_T
> >  AC_MANUAL_FORMAT
> >  
> > +AC_CHECK_MEMBERS([struct dirent.d_reclen],[],[],[[#include <dirent.h>]])
> > +AC_SUBST(ac_cv_member_struct_dirent_d_reclen)
> > +AC_CHECK_MEMBERS([struct dirent.d_off],[],[],[[#include <dirent.h>]])
> > +AC_SUBST(ac_cv_member_struct_dirent_d_off)
> > +AC_CHECK_MEMBERS([struct dirent.d_type],[],[],[[#include <dirent.h>]])
> > +AC_SUBST(ac_cv_member_struct_dirent_d_type)
> > +
> >  AC_CONFIG_FILES([include/builddefs])
> >  AC_OUTPUT
> > diff --git a/include/builddefs.in b/include/builddefs.in
> > index b5ce336..67d963c 100644
> > --- a/include/builddefs.in
> > +++ b/include/builddefs.in
> > @@ -109,6 +109,10 @@ HAVE_FLS = @have_fls@
> >  HAVE_FSETXATTR = @have_fsetxattr@
> >  HAVE_MREMAP = @have_mremap@
> >  
> > +HAVE_STRUCT_DIRENT_D_RECLEN = @ac_cv_member_struct_dirent_d_reclen@
> > +HAVE_STRUCT_DIRENT_D_OFF = @ac_cv_member_struct_dirent_d_off@
> > +HAVE_STRUCT_DIRENT_D_TYPE = @ac_cv_member_struct_dirent_d_type@
> > +
> >  GCCFLAGS = -funsigned-char -fno-strict-aliasing -Wall
> >  #	   -Wbitwise -Wno-transparent-union -Wno-old-initializer -Wno-decl
> >  
> > diff --git a/io/Makefile b/io/Makefile
> > index 0b53f41..9574168 100644
> > --- a/io/Makefile
> > +++ b/io/Makefile
> > @@ -94,6 +94,16 @@ ifeq ($(HAVE_MREMAP),yes)
> >  LCFLAGS += -DHAVE_MREMAP
> >  endif
> >  
> > +ifeq ($(HAVE_STRUCT_DIRENT_D_RECLEN),yes)
> > +LCFLAGS += -D_DIRENT_HAVE_D_RECLEN
> > +endif
> 
> The C library should be defining these if those fields are
> supported, right?

It is strongly advised not to use these non-standard fields of dirent.
These macros are a feature of glibc. See also

https://seiscode.iris.washington.edu/issues/676

Felix