* Re: Obvious fix in values.c?
2002-04-19 15:58 ` Daniel Jacobowitz
2002-04-19 16:23 ` Jim Ingham
@ 2002-05-11 16:46 ` Daniel Jacobowitz
1 sibling, 0 replies; 6+ messages in thread
From: Daniel Jacobowitz @ 2002-05-11 16:46 UTC (permalink / raw)
To: Jim Ingham, gdb-patches
On Fri, Apr 19, 2002 at 06:58:37PM -0400, Daniel Jacobowitz wrote:
> On Fri, Apr 19, 2002 at 02:28:44PM -0700, Jim Ingham wrote:
> > Do folks agree that this falls under the obvious fix rule? It doesn't
> > seem safe to assume that all demangled names will contain a space (and
> > in fact, gdb crashed on someone when the assumption was proved false...).
> >
> > 2002-04-19 Jim Ingham <jingham@apple.com>
> >
> > * values.c (value_headof): Don't assume all demangled names contain
> > a space.
>
> Could I please get you to solve this properly? Kill the one and only
> use of this function in printcmd.c via value_from_vtable_info. If you
> simply cast the pointer to a pointer to the proper base type, found via
> value_rtti_type, this function can die. It should just work (and/or be
> more useful than the current behavior).
Rather than file a change request, I did it myself.
I can't tell when the code to check objectprint in c_val_print came
along; the ChangeLogs are a little unclear. However, it is superior to
the matching code in printcmd.c, and completely obsoletes it. I've
killed the block in printcmd, and also the value_headof and
value_from_vtable_info functions. And the TODO entry telling me to do
this. The crash point above is deleted and 'set print object 1'
continues to work in all my testcases.
I've committed this.
--
Daniel Jacobowitz Carnegie Mellon University
MontaVista Software Debian GNU/Linux Developer
2002-05-11 Daniel Jacobowitz <drow@mvista.com>
* TODO: Remove value_headof/value_from_vtable_info comment.
* printcmd.c (print_command_1): Don't call value_from_vtable_info.
* values.c (value_headof, value_from_vtable_info): Delete.
* value.h (value_from_vtable_info): Delete prototype.
Index: TODO
===================================================================
RCS file: /cvs/src/src/gdb/TODO,v
retrieving revision 1.95
diff -u -p -r1.95 TODO
--- TODO 13 Jan 2002 16:16:58 -0000 1.95
+++ TODO 11 May 2002 23:27:51 -0000
@@ -247,10 +247,6 @@ New languages come onto the scene all th
Re: Various C++ things
-value_headof/value_from_vtable_info are worthless, and should be
-removed. The one place in printcmd.c that uses it should use the RTTI
-functions.
-
RTTI for g++ should be using the typeinfo functions rather than the
vtables. The typeinfo functions are always at offset 4 from the
beginning of the vtable, and are always right. The vtables will have
Index: printcmd.c
===================================================================
RCS file: /cvs/src/src/gdb/printcmd.c,v
retrieving revision 1.38
diff -u -p -r1.38 printcmd.c
--- printcmd.c 5 Apr 2002 22:04:41 -0000 1.38
+++ printcmd.c 11 May 2002 23:27:54 -0000
@@ -923,25 +923,6 @@ print_command_1 (char *exp, int inspect,
old_chain = make_cleanup (free_current_contents, &expr);
cleanup = 1;
val = evaluate_expression (expr);
-
- /* C++: figure out what type we actually want to print it as. */
- type = VALUE_TYPE (val);
-
- if (objectprint
- && (TYPE_CODE (type) == TYPE_CODE_PTR
- || TYPE_CODE (type) == TYPE_CODE_REF)
- && (TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_STRUCT
- || TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_UNION))
- {
- struct value *v;
-
- v = value_from_vtable_info (val, TYPE_TARGET_TYPE (type));
- if (v != 0)
- {
- val = v;
- type = VALUE_TYPE (val);
- }
- }
}
else
val = access_value_history (0);
Index: value.h
===================================================================
RCS file: /cvs/src/src/gdb/value.h,v
retrieving revision 1.29
diff -u -p -r1.29 value.h
--- value.h 17 Mar 2002 01:32:54 -0000 1.29
+++ value.h 11 May 2002 23:27:55 -0000
@@ -405,9 +405,6 @@ extern struct value *value_repeat (struc
extern struct value *value_subscript (struct value *array, struct value *idx);
-extern struct value *value_from_vtable_info (struct value *arg,
- struct type *type);
-
extern struct value *value_being_returned (struct type *valtype,
char *retbuf, int struct_return);
Index: values.c
===================================================================
RCS file: /cvs/src/src/gdb/values.c,v
retrieving revision 1.34
diff -u -p -r1.34 values.c
--- values.c 29 Jan 2002 03:08:26 -0000 1.34
+++ values.c 11 May 2002 23:27:57 -0000
@@ -41,8 +41,6 @@ void _initialize_values (void);
/* Prototypes for local functions. */
-static struct value *value_headof (struct value *, struct type *, struct type *);
-
static void show_values (char *, int);
static void show_convenience (char *, int);
@@ -1020,93 +1018,6 @@ value_fn_field (struct value **arg1p, st
return v;
}
-/* ARG is a pointer to an object we know to be at least
- a DTYPE. BTYPE is the most derived basetype that has
- already been searched (and need not be searched again).
- After looking at the vtables between BTYPE and DTYPE,
- return the most derived type we find. The caller must
- be satisfied when the return value == DTYPE.
-
- FIXME-tiemann: should work with dossier entries as well.
- NOTICE - djb: I see no good reason at all to keep this function now that
- we have RTTI support. It's used in literally one place, and it's
- hard to keep this function up to date when it's purpose is served
- by value_rtti_type efficiently.
- Consider it gone for 5.1. */
-
-static struct value *
-value_headof (struct value *in_arg, struct type *btype, struct type *dtype)
-{
- /* First collect the vtables we must look at for this object. */
- struct value *arg;
- struct value *vtbl;
- struct symbol *sym;
- char *demangled_name;
- struct minimal_symbol *msymbol;
-
- btype = TYPE_VPTR_BASETYPE (dtype);
- CHECK_TYPEDEF (btype);
- arg = in_arg;
- if (btype != dtype)
- arg = value_cast (lookup_pointer_type (btype), arg);
- if (TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_REF)
- {
- /*
- * Copy the value, but change the type from (T&) to (T*).
- * We keep the same location information, which is efficient,
- * and allows &(&X) to get the location containing the reference.
- */
- arg = value_copy (arg);
- VALUE_TYPE (arg) = lookup_pointer_type (TYPE_TARGET_TYPE (VALUE_TYPE (arg)));
- }
- if (VALUE_ADDRESS(value_field (value_ind(arg), TYPE_VPTR_FIELDNO (btype)))==0)
- return arg;
-
- vtbl = value_ind (value_field (value_ind (arg), TYPE_VPTR_FIELDNO (btype)));
- /* Turn vtable into typeinfo function */
- VALUE_OFFSET(vtbl)+=4;
-
- msymbol = lookup_minimal_symbol_by_pc ( value_as_address(value_ind(vtbl)) );
- if (msymbol == NULL
- || (demangled_name = SYMBOL_NAME (msymbol)) == NULL)
- {
- /* If we expected to find a vtable, but did not, let the user
- know that we aren't happy, but don't throw an error.
- FIXME: there has to be a better way to do this. */
- struct type *error_type = (struct type *) xmalloc (sizeof (struct type));
- memcpy (error_type, VALUE_TYPE (in_arg), sizeof (struct type));
- TYPE_NAME (error_type) = savestring ("suspicious *", sizeof ("suspicious *"));
- VALUE_TYPE (in_arg) = error_type;
- return in_arg;
- }
- demangled_name = cplus_demangle(demangled_name,DMGL_ANSI);
- *(strchr (demangled_name, ' ')) = '\0';
-
- sym = lookup_symbol (demangled_name, 0, VAR_NAMESPACE, 0, 0);
- if (sym == NULL)
- error ("could not find type declaration for `%s'", demangled_name);
-
- arg = in_arg;
- VALUE_TYPE (arg) = lookup_pointer_type (SYMBOL_TYPE (sym));
- return arg;
-}
-
-/* ARG is a pointer object of type TYPE. If TYPE has virtual
- function tables, probe ARG's tables (including the vtables
- of its baseclasses) to figure out the most derived type that ARG
- could actually be a pointer to. */
-
-struct value *
-value_from_vtable_info (struct value *arg, struct type *type)
-{
- /* Take care of preliminaries. */
- if (TYPE_VPTR_FIELDNO (type) < 0)
- fill_in_vptr_fieldno (type);
- if (TYPE_VPTR_FIELDNO (type) < 0)
- return 0;
-
- return value_headof (arg, 0, type);
-}
\f
/* Unpack a field FIELDNO of the specified TYPE, from the anonymous object at
VALADDR.
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