Re: MacOSX emacs crashes after 10.4.3 update

[YAMAMOTO Mitsuharu]

>>>>> On Sun, 6 Nov 2005 16:46:45 +0900, Seiji Zenitani <address@hidden> said:

> Yamamoto-san,
>> > Have you tried setting the environment variable >
>> MACOSX_DEPLOYMENT_TARGET=10.4 ?  E.g.
>> 
>> > MACOSX_DEPLOYMENT_TARGET=10.4 ./make-package (...)
>> 
>> > I heard that helps you build binaries that run on all 10.4
>> versions.
>> 
>> Do you have any references explaining why it works (or why binary
>> compatibility is broken without it)?

> I hope Nozomu Ando-san's description (in Japanese language) will be
> helpful.

> http://homepage.mac.com/nand/macosx/emacs_cross.html

Thanks for the info.  He says "MACOSX_DEPLOYMENT_TARGET=10.4 ..." is
not a fix but a workaround.

I'm very new to Tiger and I just started using it after the 10.4.3
release, but now I think I understand the situation.  This is not a
Carbon-specific issue, but every build on Mac OS X 10.4/Darwin 8 PPC
is affected.

  http://darwinsource.opendarwin.org/10.4.3/xnu-792.6.22/bsd/sys/cdefs.h
  (about "long double compatibility")

  http://darwinsource.opendarwin.org/10.4.3/SystemStubs-5/

Ironically, this mechanism seems to be introduced for binary
compatibility.

Ando-san, what do you think about the following change?  It clears a
part of the __bss section on unexec, where the cleared part is located
after the static uninitialized variables in the Emacs source.  I tried
to make an executable on 10.4.3 (linked with libncurses.5.dynlib),
then it could be executed on 10.3.9.

                                     YAMAMOTO Mitsuharu
                                address@hidden

Index: src/unexmacosx.c
===================================================================
RCS file: /cvsroot/emacs/emacs/src/unexmacosx.c,v
retrieving revision 1.15
diff -c -r1.15 unexmacosx.c
*** src/unexmacosx.c    7 Aug 2005 12:33:18 -0000       1.15
--- src/unexmacosx.c    8 Nov 2005 00:44:25 -0000
***************
*** 193,198 ****
--- 193,221 ----
    return write (outfd, src, count) == count;
  }
  
+ /* Clear n bytes in outfd starting at offset dest.  Return true if
+    successful, false otherwise.  */
+ static int
+ unexec_clear (off_t dest, size_t count)
+ {
+   char buf[UNEXEC_COPY_BUFSZ];
+   ssize_t bytes;
+ 
+   bzero (buf, UNEXEC_COPY_BUFSZ);
+   if (lseek (outfd, dest, SEEK_SET) != dest)
+     return 0;
+ 
+   while (count > 0)
+     {
+       bytes = count > UNEXEC_COPY_BUFSZ ? UNEXEC_COPY_BUFSZ : count;
+       if (write (outfd, buf, bytes) != bytes)
+       return 0;
+       count -= bytes;
+     }
+ 
+   return 1;
+ }
+ 
  /* Copy n bytes from starting offset src in infd to starting offset
     dest in outfd.  Return true if successful, false otherwise.  */
  static int
***************
*** 684,697 ****
          if (!unexec_write (header_offset, sectp, sizeof (struct section)))
            unexec_error ("cannot write section %s's header", SECT_DATA);
        }
!       else if (strncmp (sectp->sectname, SECT_BSS, 16) == 0
!              || strncmp (sectp->sectname, SECT_COMMON, 16) == 0)
        {
          sectp->flags = S_REGULAR;
          if (!unexec_write (sectp->offset, (void *) sectp->addr, sectp->size))
!           unexec_error ("cannot write section %s", SECT_DATA);
          if (!unexec_write (header_offset, sectp, sizeof (struct section)))
!           unexec_error ("cannot write section %s's header", SECT_DATA);
        }
        else if (strncmp (sectp->sectname, "__la_symbol_ptr", 16) == 0
               || strncmp (sectp->sectname, "__nl_symbol_ptr", 16) == 0
--- 707,737 ----
          if (!unexec_write (header_offset, sectp, sizeof (struct section)))
            unexec_error ("cannot write section %s's header", SECT_DATA);
        }
!       else if (strncmp (sectp->sectname, SECT_COMMON, 16) == 0)
        {
          sectp->flags = S_REGULAR;
          if (!unexec_write (sectp->offset, (void *) sectp->addr, sectp->size))
!           unexec_error ("cannot write section %s", SECT_COMMON);
          if (!unexec_write (header_offset, sectp, sizeof (struct section)))
!           unexec_error ("cannot write section %s's header", SECT_COMMON);
!       }
!       else if (strncmp (sectp->sectname, SECT_BSS, 16) == 0)
!       {
!         extern char *my_endbss_static;
!         unsigned long my_end = (unsigned long)my_endbss_static;
! 
!         assert (sectp->addr <= my_end
!                 && my_end <= sectp->addr + sectp->size);
! 
!         sectp->flags = S_REGULAR;
!         if (!unexec_write (sectp->offset, (void *) sectp->addr,
!                            my_end - sectp->addr))
!           unexec_error ("cannot write section %s", SECT_BSS);
!         if (!unexec_clear (sectp->offset + (my_end - sectp->addr),
!                            sectp->size - (my_end - sectp->addr)))
!           unexec_error ("cannot write section %s", SECT_BSS);
!         if (!unexec_write (header_offset, sectp, sizeof (struct section)))
!           unexec_error ("cannot write section %s's header", SECT_BSS);
        }
        else if (strncmp (sectp->sectname, "__la_symbol_ptr", 16) == 0
               || strncmp (sectp->sectname, "__nl_symbol_ptr", 16) == 0