Re: "[PATCH] - cpplib mem init"

[Zack Weinberg <zack at wolery dot cumb dot org>]

On Mon, Jul 10, 2000 at 11:43:48AM -0700, Donn Terry wrote:

>Later code assumes that pfile->contexts is initialized to zero; make it so.
>(This fixes a real bug that I ran across.)

I believe it should only be necessary to clear the base context; all
other contexts are properly initialized when they are stacked.

>Also, add casts to a couple of memory management calls to cast away
>const-ness, which some compilers complain about.

This needs to be writen (PTR) whatever, not (void *) whatever, in
order to play nice with K+R compilers.

I'm testing this modified version of your patch; mind giving it a
whirl yourself?  (It will be offset due to other changes in my tree
which I've edited out of the patch.)

zw

===================================================================
Index: cpplex.c
--- cpplex.c	2000/07/09 09:19:44	1.66
+++ cpplex.c	2000/07/11 01:48:20
@@ -1994,7 +1990,7 @@ free_macro_args (args)
      macro_args *args;
 {
   if (args->tokens)
-    free (args->tokens);
+    free ((PTR) args->tokens);
   free (args->ends);
   free (args);
 }
@@ -2090,7 +2086,8 @@ save_token (args, token)
     {
       args->capacity += args->capacity + 100;
       args->tokens = (const cpp_token **)
-	xrealloc (args->tokens, args->capacity * sizeof (const cpp_token *));
+	xrealloc ((PTR) args->tokens,
+		  args->capacity * sizeof (const cpp_token *));
     }
   args->tokens[args->used++] = token;
 }
@@ -3274,18 +3276,26 @@ void
 _cpp_init_input_buffer (pfile)
      cpp_reader *pfile;
 {
+  cpp_context *base;
+
   init_trigraph_map ();
+  _cpp_init_toklist (&pfile->token_list, DUMMY_TOKEN);
+  pfile->no_expand_level = UINT_MAX;
   pfile->context_cap = 20;
-  pfile->contexts = (cpp_context *)
-    xmalloc (pfile->context_cap * sizeof (cpp_context));
   pfile->cur_context = 0;
-  pfile->contexts[0].u.list = &pfile->token_list;
 
-  pfile->contexts[0].posn = 0;
-  pfile->contexts[0].count = 0;
-  pfile->no_expand_level = UINT_MAX;
+  pfile->contexts = (cpp_context *)
+    xmalloc (pfile->context_cap * sizeof (cpp_context));
 
-  _cpp_init_toklist (&pfile->token_list, DUMMY_TOKEN);
+  /* Clear the base context.  */
+  base = &pfile->contexts[0];
+  base->u.list = &pfile->token_list;
+  base->posn = 0;
+  base->count = 0;
+  base->args = 0;
+  base->level = 0;
+  base->flags = 0;
+  base->pushed_token = 0;
 }
 
 /* Moves to the end of the directive line, popping contexts as