[Build failure] tm struct tm_gmtoff field build error

[Build failure] tm struct tm_gmtoff field build error

[Pierre Muller]

  Trying to compile a "--enable-targets=all" GDB
on current cvs HEAD on cygwin,
I found a new error in src/bfd:
libtool: compile:  gcc -DHAVE_CONFIG_H -I. -I../../purecvs/bfd -I. -I.
-I../../p
urecvs/bfd -I../../purecvs/bfd/../include -W -Wall -Wstrict-prototypes
-Wmissing
-prototypes -Werror -g -O2 -c ../../purecvs/bfd/vmsutil.c -o vmsutil.o
../../purecvs/bfd/vmsutil.c: In function `vms_file_stats_name':
../../purecvs/bfd/vmsutil.c:249: error: structure has no member named
`tm_gmtoff
'
make[3]: *** [vmsutil.lo] Error 1

245-
246-  if (cdt)
247-    {
248-      ts = localtime (&buff.st_mtime);
249:      gmtoff = ts->tm_gmtoff;
250-      *cdt = (long long) (((buff.st_mtim.tv_sec + gmtoff) *
VMS_GRANULARITY_FACTOR)
251-                          + (buff.st_mtim.tv_nsec / 100))
252-                         + VMS_EPOCH_OFFSET;
253-    }

The failure is related to a commit by Nick Clifton dated January 15. 2009
adding vmsutils.c file.

tm_gmtoff seems to be an optional field according to:
http://www.delorie.com/gnu/docs/glibc/libc_435.html

and some configure script do check for its presence
before using it, for instance
src/config/tcl.m4
    AC_CACHE_CHECK([tm_gmtoff in struct tm], tcl_cv_member_tm_gmtoff, [
        AC_TRY_COMPILE([#include <time.h>], [struct tm tm; tm.tm_gmtoff;],
            tcl_cv_member_tm_gmtoff=yes, tcl_cv_member_tm_gmtoff=no)])
    if test $tcl_cv_member_tm_gmtoff = yes ; then
        AC_DEFINE(HAVE_TM_GMTOFF)
    fi

Could this test be added and vmsutils.c
be updated accordingly?

Thanks in advance,


Pierre Muller
Pascal language support maintainer for GDB

Re: [Build failure] tm struct tm_gmtoff field build error

[Cary Coutant]

> Trying to compile a "--enable-targets=all" GDB
> on current cvs HEAD on cygwin,
> I found a new error in src/bfd:
> libtool: compile:  gcc -DHAVE_CONFIG_H -I. -I../../purecvs/bfd -I. -I.
> -I../../p
> urecvs/bfd -I../../purecvs/bfd/../include -W -Wall -Wstrict-prototypes
> -Wmissing
> -prototypes -Werror -g -O2 -c ../../purecvs/bfd/vmsutil.c -o vmsutil.o
> ../../purecvs/bfd/vmsutil.c: In function `vms_file_stats_name':
> ../../purecvs/bfd/vmsutil.c:249: error: structure has no member named
> `tm_gmtoff'

Nick's follow-up patch on 1/21 still didn't fix the compilation
problems. The non-VMS code in this routine seems a bit confused:

  struct stat buff;
  struct tm *ts;

  if ((stat (filename, &buff)) != 0)
     return 1;

  if (cdt)
    {
      ts = localtime (&buff.st_mtime);
      *cdt = (long long) ((buff.st_mtim.tv_sec * VMS_GRANULARITY_FACTOR)
                          + (buff.st_mtim.tv_nsec / 100))
                         + VMS_EPOCH_OFFSET;
    }

The call to localtime was apparently there originally to get the
tm_gmtoff value -- after the 1/21 patch, the variable ts is not used.
On top of that, st_mtime is misspelled twice, and, when spelled
correctly, isn't a struct timeval, so it doesn't have tv_sec and
tv_nsec fields. This appears to be an attempt to get sub-second
granularity, but as far as I know, the stat() call does not provide
it.

I propose the following patch, but since I'm not sure what the code is
really meant to be doing, I don't consider it obvious.

-cary


        * vmsutil.c (vms_file_stats_name): Fix incorrect use of
st_mtime in struct stat.


Index: vmsutil.c
===================================================================
RCS file: /cvs/src/src/bfd/vmsutil.c,v
retrieving revision 1.2
diff -u -p -r1.2 vmsutil.c
--- vmsutil.c	21 Jan 2009 11:58:05 -0000	1.2
+++ vmsutil.c	17 Feb 2009 21:32:30 -0000
@@ -237,16 +237,13 @@ vms_file_stats_name (const char *filenam
   return 0;
 #else
   struct stat buff;
-  struct tm *ts;

   if ((stat (filename, &buff)) != 0)
      return 1;

   if (cdt)
     {
-      ts = localtime (&buff.st_mtime);
-      *cdt = (long long) ((buff.st_mtim.tv_sec * VMS_GRANULARITY_FACTOR)
-                          + (buff.st_mtim.tv_nsec / 100))
+      *cdt = (long long) (buff.st_mtime * VMS_GRANULARITY_FACTOR)
                          + VMS_EPOCH_OFFSET;
     }

Re: [Build failure] tm struct tm_gmtoff field build error

[Nick Clifton]

Hi Cary,

>         * vmsutil.c (vms_file_stats_name): Fix incorrect use of
> st_mtime in struct stat.

Approved - please apply.

Note - personally I do not think that we should be storing timestamps in 
binaries at all since it makes comparisons of identical files 
impossible, but that is another issue.

Cheers
   Nick

Re: [Build failure] tm struct tm_gmtoff field build error

[Cary Coutant]

>>        * vmsutil.c (vms_file_stats_name): Fix incorrect use of
>> st_mtime in struct stat.
>
> Approved - please apply.

Applied.

-cary