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Re: [RFA] Fix calling of static C++ member functions
- From: Daniel Jacobowitz <drow at mvista dot com>
- To: "Peter.Schauer" <Peter dot Schauer at regent dot e-technik dot tu-muenchen dot de>
- Cc: gdb-patches at sources dot redhat dot com
- Date: Sat, 11 May 2002 22:21:34 -0400
- Subject: Re: [RFA] Fix calling of static C++ member functions
- References: <200203151044.LAA28144@reisser.regent.e-technik.tu-muenchen.de>
On Fri, Mar 15, 2002 at 11:44:46AM +0100, Peter.Schauer wrote:
> This one fixes
> http://sources.redhat.com/ml/bug-gdb/2001-06/msg00059.html
> which is still broken in CVS Head GDB.
>
> Actually there are a bunch problems:
>
> - The printing of the bad value happens, because find_overload_match does
> not set *staticp for static member functions.
>
> - The crash happens because in
> domain = TYPE_DOMAIN_TYPE (fns_ptr[0].type);
> in find_overload_match we don't find the domain, as find_method_list
> doesn't handle stub methods correctly and it's too late in
> find_overload_match. Checking for stub methods in find_method_list
> instead gets rid of the crash.
>
> - When trying the provided testcase for dwarf2, more problems arise.
> Until now check_stub_method did not handle static member
> functions correctly, as the this parameter was added unconditionally.
> After fixing this, we also have to adjust typecmp, so that static
> member functions also work with `set overload off'.
> And finally we have to fix find_overload_match, to make it behave properly
> in the `set overload on' case.
>
> The patch below fixes the calling of static member functions for
> gcc-2.95.2/gcc-3.x and stabs/dwarf2 debugging, ok to commit ?
I had to make some substantial changes to this. First of all, I wanted
to kill the now-obsolete static_memfuncp argument to find_method_list.
Secondly, the way you were skipping THIS in typecmp caused segfaults
for some methods which only expected one argument. Here's what I
checked in.
I -think- I'm caught up on all the patches you sent me now, Peter.
> 2002-03-15 Peter Schauer <pes@regent.e-technik.tu-muenchen.de>
>
> Fix calling of static member functions.
> * gdbtypes.c (check_stub_method): Handle static member functions.
> * valops.c (typecmp): Handle static member functions correctly.
> (find_overload_match): Ditto, set *staticp for static member
> functions.
> (find_method_list): Check for stub functions here, not in
> find_overload_match.
--
Daniel Jacobowitz Carnegie Mellon University
MontaVista Software Debian GNU/Linux Developer
2005-05-11 Daniel Jacobowitz <drow@mvista.com>
Peter Schauer <pes@regent.e-technik.tu-muenchen.de>
* Makefile.in: Update dependencies for valops.c.
* valops.c: Include "gdb_assert.h".
(typecmp): Skip THIS parameter to methods.
(find_method_list): Remove static_memfuncp argument,
update callers. Check for stub methods.
(find_value_oload_method_list): Don't set *static_memfuncp.
(find_overload_match): Don't check for stub methods. Assert
that methods are not stubbed. Handle static methods.
(value_find_oload_method_list): Remove static_memfuncp argument.
* gdbtypes.c (check_stub_method): Do not add THIS pointer
to the argument list for static stub methods.
* value.h (value_find_oload_method_list): Update prototype.
Index: valops.c
===================================================================
RCS file: /cvs/src/src/gdb/valops.c,v
retrieving revision 1.56
diff -u -p -r1.56 valops.c
--- valops.c 2 May 2002 19:00:36 -0000 1.56
+++ valops.c 12 May 2002 02:08:08 -0000
@@ -36,6 +36,7 @@
#include <errno.h>
#include "gdb_string.h"
+#include "gdb_assert.h"
/* Flag indicating HP compilers were used; needed to correctly handle some
value operations with HP aCC code/runtime. */
@@ -66,7 +67,7 @@ static CORE_ADDR allocate_space_in_infer
static struct value *cast_into_complex (struct type *, struct value *);
static struct fn_field *find_method_list (struct value ** argp, char *method,
- int offset, int *static_memfuncp,
+ int offset,
struct type *type, int *num_fns,
struct type **basetype,
int *boffset);
@@ -1963,10 +1964,13 @@ typecmp (int staticp, struct type *t1[],
return t2[1] != 0;
if (t1 == 0)
return 1;
- if (TYPE_CODE (t1[0]) == TYPE_CODE_VOID)
- return 0;
if (t1[!staticp] == 0)
return 0;
+ if (TYPE_CODE (t1[0]) == TYPE_CODE_VOID)
+ return 0;
+ /* Skip ``this'' argument if applicable. T2 will always include THIS. */
+ if (staticp)
+ t2++;
for (i = !staticp; t1[i] && TYPE_CODE (t1[i]) != TYPE_CODE_VOID; i++)
{
struct type *tt1, *tt2;
@@ -2520,7 +2524,7 @@ value_struct_elt (struct value **argp, s
static struct fn_field *
find_method_list (struct value **argp, char *method, int offset,
- int *static_memfuncp, struct type *type, int *num_fns,
+ struct type *type, int *num_fns,
struct type **basetype, int *boffset)
{
int i;
@@ -2536,10 +2540,22 @@ find_method_list (struct value **argp, c
char *fn_field_name = TYPE_FN_FIELDLIST_NAME (type, i);
if (fn_field_name && (strcmp_iw (fn_field_name, method) == 0))
{
- *num_fns = TYPE_FN_FIELDLIST_LENGTH (type, i);
+ /* Resolve any stub methods. */
+ int len = TYPE_FN_FIELDLIST_LENGTH (type, i);
+ struct fn_field *f = TYPE_FN_FIELDLIST1 (type, i);
+ int j;
+
+ *num_fns = len;
*basetype = type;
*boffset = offset;
- return TYPE_FN_FIELDLIST1 (type, i);
+
+ for (j = 0; j < len; j++)
+ {
+ if (TYPE_FN_FIELD_STUB (f, j))
+ check_stub_method (type, i, j);
+ }
+
+ return f;
}
}
@@ -2579,7 +2595,8 @@ find_method_list (struct value **argp, c
base_offset = TYPE_BASECLASS_BITPOS (type, i) / 8;
}
f = find_method_list (argp, method, base_offset + offset,
- static_memfuncp, TYPE_BASECLASS (type, i), num_fns, basetype, boffset);
+ TYPE_BASECLASS (type, i), num_fns, basetype,
+ boffset);
if (f)
return f;
}
@@ -2597,8 +2614,8 @@ find_method_list (struct value **argp, c
struct fn_field *
value_find_oload_method_list (struct value **argp, char *method, int offset,
- int *static_memfuncp, int *num_fns,
- struct type **basetype, int *boffset)
+ int *num_fns, struct type **basetype,
+ int *boffset)
{
struct type *t;
@@ -2621,12 +2638,7 @@ value_find_oload_method_list (struct val
&& TYPE_CODE (t) != TYPE_CODE_UNION)
error ("Attempt to extract a component of a value that is not a struct or union");
- /* Assume it's not static, unless we see that it is. */
- if (static_memfuncp)
- *static_memfuncp = 0;
-
- return find_method_list (argp, method, 0, static_memfuncp, t, num_fns, basetype, boffset);
-
+ return find_method_list (argp, method, 0, t, num_fns, basetype, boffset);
}
/* Given an array of argument types (ARGTYPES) (which includes an
@@ -2685,6 +2697,7 @@ find_overload_match (struct type **arg_t
int boffset;
register int jj;
register int ix;
+ int static_offset;
char *obj_type_name = NULL;
char *func_name = NULL;
@@ -2692,9 +2705,6 @@ find_overload_match (struct type **arg_t
/* Get the list of overloaded methods or functions */
if (method)
{
- int i;
- int len;
- struct type *domain;
obj_type_name = TYPE_NAME (VALUE_TYPE (obj));
/* Hack: evaluate_subexp_standard often passes in a pointer
value rather than the object itself, so try again */
@@ -2703,7 +2713,6 @@ find_overload_match (struct type **arg_t
obj_type_name = TYPE_NAME (TYPE_TARGET_TYPE (VALUE_TYPE (obj)));
fns_ptr = value_find_oload_method_list (&temp, name, 0,
- staticp,
&num_fns,
&basetype, &boffset);
if (!fns_ptr || !num_fns)
@@ -2711,26 +2720,10 @@ find_overload_match (struct type **arg_t
obj_type_name,
(obj_type_name && *obj_type_name) ? "::" : "",
name);
- domain = TYPE_DOMAIN_TYPE (fns_ptr[0].type);
- len = TYPE_NFN_FIELDS (domain);
- /* NOTE: dan/2000-03-10: This stuff is for STABS, which won't
- give us the info we need directly in the types. We have to
- use the method stub conversion to get it. Be aware that this
- is by no means perfect, and if you use STABS, please move to
- DWARF-2, or something like it, because trying to improve
- overloading using STABS is really a waste of time. */
- for (i = 0; i < len; i++)
- {
- int j;
- struct fn_field *f = TYPE_FN_FIELDLIST1 (domain, i);
- int len2 = TYPE_FN_FIELDLIST_LENGTH (domain, i);
-
- for (j = 0; j < len2; j++)
- {
- if (TYPE_FN_FIELD_STUB (f, j) && (!strcmp_iw (TYPE_FN_FIELDLIST_NAME (domain,i),name)))
- check_stub_method (domain, i, j);
- }
- }
+ /* If we are dealing with stub method types, they should have
+ been resolved by find_method_list via value_find_oload_method_list
+ above. */
+ gdb_assert (TYPE_DOMAIN_TYPE (fns_ptr[0].type) != NULL);
}
else
{
@@ -2757,10 +2750,11 @@ find_overload_match (struct type **arg_t
/* Consider each candidate in turn */
for (ix = 0; ix < num_fns; ix++)
{
+ static_offset = 0;
if (method)
{
- /* For static member functions, we won't have a this pointer, but nothing
- else seems to handle them right now, so we just pretend ourselves */
+ if (TYPE_FN_FIELD_STATIC_P (fns_ptr, ix))
+ static_offset = 1;
nparms=0;
if (TYPE_FN_FIELD_ARGS(fns_ptr,ix))
@@ -2782,8 +2776,10 @@ find_overload_match (struct type **arg_t
? (TYPE_FN_FIELD_ARGS (fns_ptr, ix)[jj])
: TYPE_FIELD_TYPE (SYMBOL_TYPE (oload_syms[ix]), jj));
- /* Compare parameter types to supplied argument types */
- bv = rank_function (parm_types, nparms, arg_types, nargs);
+ /* Compare parameter types to supplied argument types. Skip THIS for
+ static methods. */
+ bv = rank_function (parm_types, nparms, arg_types + static_offset,
+ nargs - static_offset);
if (!oload_champ_bv)
{
@@ -2821,7 +2817,7 @@ find_overload_match (struct type **arg_t
fprintf_filtered (gdb_stderr,"Overloaded method instance %s, # of parms %d\n", fns_ptr[ix].physname, nparms);
else
fprintf_filtered (gdb_stderr,"Overloaded function instance %s # of parms %d\n", SYMBOL_DEMANGLED_NAME (oload_syms[ix]), nparms);
- for (jj = 0; jj < nargs; jj++)
+ for (jj = 0; jj < nargs - static_offset; jj++)
fprintf_filtered (gdb_stderr,"...Badness @ %d : %d\n", jj, bv->rank[jj]);
fprintf_filtered (gdb_stderr,"Overload resolution champion is %d, ambiguous? %d\n", oload_champ, oload_ambiguous);
}
@@ -2844,8 +2840,11 @@ find_overload_match (struct type **arg_t
}
#endif
- /* Check how bad the best match is */
- for (ix = 1; ix <= nargs; ix++)
+ /* Check how bad the best match is. */
+ static_offset = 0;
+ if (method && TYPE_FN_FIELD_STATIC_P (fns_ptr, oload_champ))
+ static_offset = 1;
+ for (ix = 1; ix <= nargs - static_offset; ix++)
{
if (oload_champ_bv->rank[ix] >= 100)
oload_incompatible = 1; /* truly mismatched types */
@@ -2878,6 +2877,10 @@ find_overload_match (struct type **arg_t
if (method)
{
+ if (staticp && TYPE_FN_FIELD_STATIC_P (fns_ptr, oload_champ))
+ *staticp = 1;
+ else if (staticp)
+ *staticp = 0;
if (TYPE_FN_FIELD_VIRTUAL_P (fns_ptr, oload_champ))
*valp = value_virtual_fn_field (&temp, fns_ptr, oload_champ, basetype, boffset);
else
Index: gdbtypes.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbtypes.c,v
retrieving revision 1.48
diff -u -p -r1.48 gdbtypes.c
--- gdbtypes.c 8 May 2002 22:58:39 -0000 1.48
+++ gdbtypes.c 12 May 2002 02:08:09 -0000
@@ -1649,9 +1649,16 @@ check_stub_method (struct type *type, in
argtypes = (struct type **)
TYPE_ALLOC (type, (argcount + 2) * sizeof (struct type *));
p = argtypetext;
- /* FIXME: This is wrong for static member functions. */
- argtypes[0] = lookup_pointer_type (type);
- argcount = 1;
+
+ /* Add THIS pointer for non-static methods. */
+ f = TYPE_FN_FIELDLIST1 (type, method_id);
+ if (TYPE_FN_FIELD_STATIC_P (f, signature_id))
+ argcount = 0;
+ else
+ {
+ argtypes[0] = lookup_pointer_type (type);
+ argcount = 1;
+ }
if (*p != ')') /* () means no args, skip while */
{
@@ -1693,8 +1700,6 @@ check_stub_method (struct type *type, in
}
xfree (demangled_name);
-
- f = TYPE_FN_FIELDLIST1 (type, method_id);
TYPE_FN_FIELD_PHYSNAME (f, signature_id) = mangled_name;
Index: value.h
===================================================================
RCS file: /cvs/src/src/gdb/value.h,v
retrieving revision 1.30
diff -u -p -r1.30 value.h
--- value.h 11 May 2002 23:48:23 -0000 1.30
+++ value.h 12 May 2002 02:08:09 -0000
@@ -375,7 +375,7 @@ extern struct value *value_struct_elt_fo
extern struct value *value_static_field (struct type *type, int fieldno);
extern struct fn_field *value_find_oload_method_list (struct value **, char *,
- int, int *, int *,
+ int, int *,
struct type **, int *);
extern int find_overload_match (struct type **arg_types, int nargs,
Index: Makefile.in
===================================================================
RCS file: /cvs/src/src/gdb/Makefile.in,v
retrieving revision 1.185
diff -u -p -r1.185 Makefile.in
--- Makefile.in 11 May 2002 23:14:25 -0000 1.185
+++ Makefile.in 12 May 2002 02:16:43 -0000
@@ -2144,7 +2144,7 @@ valarith.o: valarith.c $(bfd_h) $(defs_h
$(gdb_string_h) $(doublest_h)
valops.o: valops.c $(defs_h) $(gdbcore_h) $(inferior_h) $(target_h) \
- $(gdb_string_h) $(regcache_h) $(cp_abi_h)
+ $(gdb_string_h) $(regcache_h) $(cp_abi_h) $(gdb_assert_h)
valprint.o: valprint.c $(defs_h) $(expression_h) $(gdbcmd_h) \
$(gdbcore_h) $(gdbtypes_h) $(language_h) $(symtab_h) $(target_h) \