Re: DJGPP only dumps with USE_LISP_UNION_TYPE ??

[Jan D.]

Eli Zaretskii wrote:

> > Emacs fatal error: buffer.c:4944: assertion failed: XTYPE 
> > (&buffer_defaults) == 0
> >
> > In gdb I see that &buffer_local_symbols which is what 
> > Vbuffer_local_symbols uses, isn't aligned to an even 8 either.  These 
> > are aligned to an even 4.  So DECL_ALIGN isn't working in this 
> > configuration (?).  Sounds strange.
>
>
> Could you write a short test program that demonstrates whether
> DECL_ALIGN works, and see if it fails on XP?  (I could run it on my
> machine to see if it works on 98, which I think it does.)  If
> DECL_ALIGN doesn't work, we certainly cannot use LSB tags in the XP
> build.  We could then make the test program part of config.bat to DTRT
> at build time.
>
> Please also upgrade to a newer GCC version (I use 3.3.3), in case
> there's some alignment bug in your version.

Test program attached.  Output when compiling in Cygwin, Gnu/Linux or MacOSX 
is as expected:

ss1: rem 0
ss2: rem 0
ss3: rem 0
ss4: rem 0

but for djgpp (didn't find gcc 3.3.3, but 3.3.4):

D:\src>gcc -v
Reading specs from d:/djgpp/bin/../lib/gcc-lib/djgpp/3.34/specs
Configured with: /gcc/gnu/gcc-3.34/configure djgpp --prefix=/dev/env/DJDIR --dis
able-nls
Thread model: single
gcc version 3.3.4

D:\src>make align
gcc     align.c   -o align

D:\src>align
ss1: rem 4
ss2: rem 4
ss3: rem 4
ss4: rem 4

Very strange, considering Gnu/Linux and Cygwin are on the same machine.

        Jan D.

#include <stdio.h>

#define GCTYPEBITS 3
#  define DECL_ALIGN(type, var) \
    type __attribute__ ((__aligned__ (1 << GCTYPEBITS))) var

struct SS
{
  char *ptr;
  long nr;
};


DECL_ALIGN (struct SS, ss1);
DECL_ALIGN (struct SS, ss2);
DECL_ALIGN (struct SS, ss3);
DECL_ALIGN (struct SS, ss4);

int
main ()
{
  int rem;

  rem = (unsigned long)&ss1 % 8;
  printf ("ss1: rem %d\n", rem);
  rem = (unsigned long)&ss2 % 8;
  printf ("ss2: rem %d\n", rem);
  rem = (unsigned long)&ss3 % 8;
  printf ("ss3: rem %d\n", rem);
  rem = (unsigned long)&ss4 % 8;
  printf ("ss4: rem %d\n", rem);

  return 0;
}