[PATCH] COFF symbol merging fix

["Mark E." <snowball3 at bigfoot dot com>]

Several DJGPP users have run into link problems with binutils 2.11 that 
weren't present using 2.10. It turns out that a change somewhere else in 
binutils sometimes causes coff symbols with debugging info to be merged when 
they shouldn't.

A small C file:
void var(void)
{
  return;
}

int main()
{
  static int var;

  return 0;
}

when compiled with 'gcc -g -S x.c' generates this assembly:

	.file	"x.c"
gcc2_compiled.:
___gnu_compiled_c:
.text
	.p2align 2
	.def	_var;	.val	_var;	.scl	2;	.type	041;	.endef
.globl _var
_var:
	.def	.bf;	.val	.;	.scl	101;	.line	2;	.endef
	pushl %ebp
	movl %esp,%ebp
	.ln	2
	jmp L2
	.ln	3
#        .p2align 4,,7
L2:
	movl %ebp,%esp
	popl %ebp
	ret
	.def	.ef;	.val	.;	.scl	101;	.line	3;	.endef
	.def	_var;	.val	.;	.scl	-1;	.endef
.lcomm _var.6,4
	.p2align 2
	.def	_main;	.val	_main;	.scl	2;	.type	044;	.endef
.globl _main
_main:
	.def	.bf;	.val	.;	.scl	101;	.line	7;	.endef
	pushl %ebp
	movl %esp,%ebp
	.ln	2
	.def	_var;	.val	_var.6;	.scl	3;	.type	04;	.endef
	.ln	4
	xorl %eax,%eax
	jmp L3
	.ln	5
#        .p2align 4,,7
L3:
	movl %ebp,%esp
	popl %ebp
	ret
	.def	.ef;	.val	.;	.scl	101;	.line	5;	.endef
	.def	_main;	.val	.;	.scl	-1;	.endef

And with binutils 2.11, the nm listing is:
0000000c t .bf
00000000 t .bf
00000020 b .bss
00000020 d .data
00000017 t .ef
00000009 t .ef
00000000 t .text
00000000 t ___gnu_compiled_c
0000000c T _main
00000000 t _var
00000020 b _var.6
00000000 t gcc2_compiled.

Notice that the var from the function has been merged with the static 
declaration of var from inside main. With the fix, nm produces the correct 
listing:
0000000c t .bf
00000000 t .bf
00000020 b .bss
00000020 d .data
00000017 t .ef
00000009 t .ef
00000000 t .text
00000000 t ___gnu_compiled_c
0000000c T _main
00000020 b _var
00000000 T _var
00000020 b _var.6
00000000 t gcc2_compiled.

Please apply my fix if acceptable:

as/ChangeLog:
2001-07-01  Mark Elbrecht  <snowball3@softhome.net>

	* config/obj-coff.c (coff_frob_symbol): Don't merge if the storage
	  class of the non-debug symbol is C_NULL.

Index: obj-coff.c
===================================================================
RCS file: /cvs/src/src/gas/config/obj-coff.c,v
retrieving revision 1.49
diff -c -p -r1.49 obj-coff.c
*** obj-coff.c	2001/06/30 10:09:40	1.49
--- obj-coff.c	2001/07/01 18:10:28
*************** coff_frob_symbol (symp, punt)
*** 1180,1186 ****
  	  && S_GET_STORAGE_CLASS (symp) != C_LABEL
  	  && symbol_constant_p(symp)
  	  && (real = symbol_find_base (S_GET_NAME (symp), DO_NOT_STRIP))
! 	  && real != symp)
  	{
  	  c_symbol_merge (symp, real);
  	  *punt = 1;
--- 1180,1187 ----
  	  && S_GET_STORAGE_CLASS (symp) != C_LABEL
  	  && symbol_constant_p(symp)
  	  && (real = symbol_find_base (S_GET_NAME (symp), DO_NOT_STRIP))
! 	  && real != symp
! 	  && S_GET_STORAGE_CLASS (real) == C_NULL)
  	{
  	  c_symbol_merge (symp, real);
  	  *punt = 1;