Re: [PATCH] Objective-C language support.

Michael Snyder
2002-10-09T00:30:29Z

Adam Fedor wrote:
>
> This patch adds Objective-C language support to gdb based upon a patch
> provided by Apple Computer Inc from their version of gdb. Note that the
> patch only contains changes to existing files. New files (objc-lang.h,
> objc-lang.c, objc-exp.y) and a gdb.objc testsuite directory are located at
>
> ftp://ftp.gnustep.org/pub/gnustep/contrib/gdb-objc-patch.tar.gz

Adam, if no one objects in a few days, let's check in the following
subset of your valops.c changes. This is transparent to anyone who
isn't debugging objective c (and for those who are, it simply allows
the use of "self" in place of "this"). Note that some of the valops.c
changes are not included in this approval.

> * valops.c (value_of_local): New function.
> (value_of_this): Use it.

> Index: gdb/valops.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/valops.c,v
> retrieving revision 1.72
> diff -u -p -r1.72 valops.c
> --- gdb/valops.c 14 Sep 2002 02:09:39 -0000 1.72
> +++ gdb/valops.c 17 Sep 2002 19:31:14 -0000
> @@ -3231,18 +3245,17 @@ value_full_object (struct value *argp, s
>
>
>
> -/* C++: return the value of the class instance variable, if one exists.
> +/* Return the value of the local variable, if one exists.
> Flag COMPLAIN signals an error if the request is made in an
> inappropriate context. */
>
> struct value *
> -value_of_this (int complain)
> +value_of_local (const char *name, int complain)
> {
> struct symbol *func, *sym;
> struct block *b;
> int i;
> - static const char funny_this[] = "this";
> - struct value *this;
> + struct value * ret;
>
> if (selected_frame == 0)
> {
> @@ -3256,7 +3269,7 @@ value_of_this (int complain)
> if (!func)
> {
> if (complain)
> - error ("no `this' in nameless context");
> + error ("no %s in nameless context", name);
> else
> return 0;
> }
> @@ -3266,26 +3279,39 @@ value_of_this (int complain)
> if (i <= 0)
> {
> if (complain)
> - error ("no args, no `this'");
> + error ("no args, no %s", name);
> else
> return 0;
> }
>
> /* Calling lookup_block_symbol is necessary to get the LOC_REGISTER
> symbol instead of the LOC_ARG one (if both exist). */
> - sym = lookup_block_symbol (b, funny_this, NULL, VAR_NAMESPACE);
> + sym = lookup_block_symbol (b, name, NULL, VAR_NAMESPACE);
> if (sym == NULL)
> {
> if (complain)
> - error ("current stack frame not in method");
> + error ("current stack frame does not contain a variable named \"%s\"", name);
> else
> return NULL;
> }
>
> - this = read_var_value (sym, selected_frame);
> - if (this == 0 && complain)
> - error ("`this' argument at unknown address");
> - return this;
> + ret = read_var_value (sym, selected_frame);
> + if (ret == 0 && complain)
> + error ("%s argument unreadable", name);
> + return ret;
> +}
> +
> +/* C++/Objective-C: return the value of the class instance variable,
> + if one exists. Flag COMPLAIN signals an error if the request is
> + made in an inappropriate context. */
> +
> +struct value *
> +value_of_this (int complain)
> +{
> + if (current_language->la_language == language_objc)
> + return value_of_local ("self", complain);
> + else
> + return value_of_local ("this", complain);
> }
>
> /* Create a slice (sub-string, sub-array) of ARRAY, that is LENGTH elements