change behavior of elfos.h slightly

[Jason R Thorpe <thorpej at zembu dot com>]

Hi folks...

I'm in the midst of rewriting the NetBSD GCC configurations, and am
trying to toss as much of the needless duplication in the header files
as possible.  I decided to use config/elfos.h to do this, but needed to
make a few small modifications.  I'm submitting this patch now so that
I can rethink my strategy if this one is rejected.  Changes are:

	ASM_OUTPUT_IDENT: undef before redefining, so as to override
	any definition which may have snuck in.

	LOCAL_LABEL_PREFIX: cause an error if this is not defined,
	as it is required for correct local labels to be generated.

	ASM_OUTPUT_INTERNAL_LABEL: use LOCAL_LABEL_PREFIX rather
	than assuming one of ".".

	ASM_GENERATE_INTERNAL_LABEL: Likewise.

The latter two are required in order to be able to use elfos.h on
e.g. MIPS and Alpha targets (assuming you want those targets to
continue to use the "$" as their local label prefix).

Note that I have not verified that other users of elfos.h still compile.

-- 
        -- Jason R. Thorpe <thorpej@zembu.com>


Index: elfos.h
===================================================================
RCS file: /cvs/gcc/egcs/gcc/config/elfos.h,v
retrieving revision 1.16
diff -c -r1.16 elfos.h
*** elfos.h	2000/04/12 00:29:43	1.16
--- elfos.h	2000/05/04 00:05:11
***************
*** 90,95 ****
--- 90,96 ----
  
  /* Output #ident as a .ident.  */
  
+ #undef  ASM_OUTPUT_IDENT
  #define ASM_OUTPUT_IDENT(FILE, NAME) \
    fprintf (FILE, "\t%s\t\"%s\"\n", IDENT_ASM_OP, NAME);
  
***************
*** 115,120 ****
--- 116,128 ----
  #undef  SET_ASM_OP
  #define SET_ASM_OP	".set"
  
+ /* We require that the includer of this file has specified the correct
+    LOCAL_LABEL_PREFIX; it's used below.  */
+ 
+ #ifndef LOCAL_LABEL_PREFIX
+ #error LOCAL_LABEL_PREFIX not defined -- check configuration
+ #endif
+ 
  /* This is how to begin an assembly language file.  Most svr4 assemblers want
     at least a .file directive to come first, and some want to see a .version
     directive come right after that.  Here we just establish a default
***************
*** 142,152 ****
     with a period is not put into the linker symbol table by the assembler.  */
  
  #undef  ASM_OUTPUT_INTERNAL_LABEL
! #define ASM_OUTPUT_INTERNAL_LABEL(FILE, PREFIX, NUM)	\
!   do							\
!     {							\
!       fprintf (FILE, ".%s%d:\n", PREFIX, NUM);		\
!     }							\
    while (0)
  
  /* This is how to store into the string LABEL
--- 150,160 ----
     with a period is not put into the linker symbol table by the assembler.  */
  
  #undef  ASM_OUTPUT_INTERNAL_LABEL
! #define ASM_OUTPUT_INTERNAL_LABEL(FILE, PREFIX, NUM)			\
!   do									\
!     {									\
!       fprintf (FILE, "%s%s%d:\n", LOCAL_LABEL_PREFIX, PREFIX, NUM);	\
!     }									\
    while (0)
  
  /* This is how to store into the string LABEL
***************
*** 161,167 ****
  #define ASM_GENERATE_INTERNAL_LABEL(LABEL, PREFIX, NUM)		\
    do								\
      {								\
!       sprintf (LABEL, "*.%s%d", PREFIX, (unsigned) (NUM));	\
      }								\
    while (0)
  
--- 169,176 ----
  #define ASM_GENERATE_INTERNAL_LABEL(LABEL, PREFIX, NUM)		\
    do								\
      {								\
!       sprintf (LABEL, "*%s%s%d", LOCAL_LABEL_PREFIX, PREFIX,	\
!                (unsigned) (NUM));				\
      }								\
    while (0)