[patch] fix declaration of obsavestring

[David Carlton <carlton at math dot stanford dot edu>]

I recently wanted to use obsavestring, and I noticed that its
declaration wasn't as good as it could be: the first argument might as
well be a const char *, and there should be an opaque declaration for
struct obstack somewhere.

Here's a patch for that; it seems obvious, so I'll commit it in a few
days if nobody objects.

David Carlton
carlton@math.stanford.edu

2002-10-09  David Carlton  <carlton@math.stanford.edu>

	* symfile.h: Add opaque declaration for struct obstack.
	Declare obsavestring to take a const char *.
	* symfile.c (obsavestring): Make first argument a const char *.

Index: symfile.h
===================================================================
RCS file: /cvs/src/src/gdb/symfile.h,v
retrieving revision 1.13
diff -u -p -r1.13 symfile.h
--- symfile.h	22 Apr 2002 10:19:04 -0000	1.13
+++ symfile.h	9 Oct 2002 16:13:35 -0000
@@ -25,6 +25,10 @@
 
 /* This file requires that you first include "bfd.h".  */
 
+/* Opaque declarations.  */
+
+struct obstack;
+
 /* Partial symbols are stored in the psymbol_cache and pointers to them
    are kept in a dynamically grown array that is obtained from malloc and
    grown as necessary via realloc.  Each objfile typically has two of these,
@@ -208,7 +212,7 @@ extern void sort_symtab_syms (struct sym
    (and add a null character at the end in the copy).
    Returns the address of the copy.  */
 
-extern char *obsavestring (char *, int, struct obstack *);
+extern char *obsavestring (const char *, int, struct obstack *);
 
 /* Concatenate strings S1, S2 and S3; return the new string.
    Space is found in the symbol_obstack.  */
Index: symfile.c
===================================================================
RCS file: /cvs/src/src/gdb/symfile.c,v
retrieving revision 1.69
diff -u -p -r1.69 symfile.c
--- symfile.c	20 Sep 2002 14:58:58 -0000	1.69
+++ symfile.c	9 Oct 2002 16:13:31 -0000
@@ -299,16 +299,16 @@ sort_symtab_syms (register struct symtab
    may be part of a larger string and we are only saving a substring. */
 
 char *
-obsavestring (char *ptr, int size, struct obstack *obstackp)
+obsavestring (const char *ptr, int size, struct obstack *obstackp)
 {
   register char *p = (char *) obstack_alloc (obstackp, size + 1);
   /* Open-coded memcpy--saves function call time.  These strings are usually
      short.  FIXME: Is this really still true with a compiler that can
      inline memcpy? */
   {
-    register char *p1 = ptr;
+    register const char *p1 = ptr;
     register char *p2 = p;
-    char *end = ptr + size;
+    const char *end = ptr + size;
     while (p1 != end)
       *p2++ = *p1++;
   }