Re: [PATCH]: swat warnings in wrapper.c

[Fernando Nasser <fnasser at cygnus dot com>]

Good catch.  Looks OK to me.

Fernando

msnyder@cygnus.com wrote:
> 
> This module uses a struct to pass multiple arguments between
> wrapper functions.  At various times it casts pointers to ints
> and vice versa.  I've modified it to use a union, so that we
> don't get warnings when pointer and int are of different size.
> 
> 2000-03-23  Michael Snyder  <msnyder@seadog.cygnus.com>
> 
>         * wrapper.[ch] (struct gdb_wrapper_arguments): change fields into
>         unions, since they are all used to hold both pointers and ints
>         at various times.  Casting pointer to int and vice versa gives
>         warnings (and is not safe) if they are not the same size.
> 
> Index: ChangeLog
> ===================================================================
> RCS file: /cvs/src/src/gdb/ChangeLog,v
> retrieving revision 1.170
> diff -r1.170 ChangeLog
> 0a1,7
> > 2000-03-23  Michael Snyder  <msnyder@seadog.cygnus.com>
> >
> >       * wrapper.[ch] (struct gdb_wrapper_arguments): change fields into
> >       unions, since they are all used to hold both pointers and ints
> >       at various times.  Casting pointer to int and vice versa gives
> >       warnings (and is not safe) if they are not the same size.
> >
> Index: wrapper.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/wrapper.c,v
> retrieving revision 1.2
> diff -r1.2 wrapper.c
> 24c24
> < /* Use this struct used to pass arguments to wrapper routines. We assume
> ---
> > /* Use this struct to pass arguments to wrapper routines. We assume
> 30c30,35
> <     char *result;
> ---
> >     union wrapper_results
> >       {
> >       int   integer;
> >       void *pointer;
> >       } result;
> >
> 33c38,42
> <     char *args[10];
> ---
> >     union wrapper_args
> >       {
> >       int   integer;
> >       void *pointer;
> >       } args[10];
> 60,62c69,71
> <   args.args[0] = (char *) stringptr;
> <   args.args[1] = (char *) block;
> <   args.args[2] = (char *) comma;
> ---
> >   args.args[0].pointer = stringptr;
> >   args.args[1].pointer = block;
> >   args.args[2].integer = comma;
> 71c80
> <   *expression = (struct expression *) args.result;
> ---
> >   *expression = (struct expression *) args.result.pointer;
> 82,84c91,93
> <   args->result = (char *) parse_exp_1((char **) args->args[0],
> <                                     (struct block *) args->args[1],
> <                                     (int) args->args[2]);
> ---
> >   args->result.pointer = parse_exp_1((char **) args->args[0].pointer,
> >                                    (struct block *) args->args[1].pointer,
> >                                    args->args[2].integer);
> 94c103
> <   args.args[0] = (char *) exp;
> ---
> >   args.args[0].pointer = exp;
> 103c112
> <   *value = (value_ptr) args.result;
> ---
> >   *value = (value_ptr) args.result.pointer;
> 113,114c122,123
> <   (args)->result =
> <     (char *) evaluate_expression ((struct expression *) (args)->args[0]);
> ---
> >   (args)->result.pointer =
> >     (char *) evaluate_expression ((struct expression *) args->args[0].pointer);
> 124c133
> <   args.args[0] = (char *) value;
> ---
> >   args.args[0].pointer = value;
> 135c144
> <   value_fetch_lazy ((value_ptr) (args)->args[0]);
> ---
> >   value_fetch_lazy ((value_ptr) (args)->args[0].pointer);
> 147,148c156,157
> <   args.args[0] = (char *) val1;
> <   args.args[1] = (char *) val2;
> ---
> >   args.args[0].pointer = val1;
> >   args.args[1].pointer = val2;
> 157c166
> <   *result = (int) args.result;
> ---
> >   *result = args.result.integer;
> 168,169c177,178
> <   val1 = (value_ptr) (args)->args[0];
> <   val2 = (value_ptr) (args)->args[1];
> ---
> >   val1 = (value_ptr) (args)->args[0].pointer;
> >   val2 = (value_ptr) (args)->args[1].pointer;
> 171c180
> <   (args)->result = (char *) value_equal (val1, val2);
> ---
> >   (args)->result.integer = value_equal (val1, val2);
> 182c191
> <   args.args[0] = (char *) val;
> ---
> >   args.args[0].pointer = val;
> 191c200
> <   *rval = (value_ptr) args.result;
> ---
> >   *rval = (value_ptr) args.result.pointer;
> 202,203c211,212
> <   val = (value_ptr) (args)->args[0];
> <   (args)->result = (char *) value_ind (val);
> ---
> >   val = (value_ptr) (args)->args[0].pointer;
> >   (args)->result.pointer = value_ind (val);
> Index: wrapper.h
> ===================================================================
> RCS file: /cvs/src/src/gdb/wrapper.h,v
> retrieving revision 1.2
> diff -r1.2 wrapper.h
> 22c22
> < /* Use this struct used to pass arguments to wrapper routines. */
> ---
> > /* Use this struct to pass arguments to wrapper routines. */

-- 
Fernando Nasser
Red Hat - Toronto                       E-Mail:  fnasser@cygnus.com
2323 Yonge Street, Suite #300           Tel:  416-482-2661 ext. 311
Toronto, Ontario   M4P 2C9              Fax:  416-482-6299