- { /* Not using HP/Taligent runtime conventions; so try to
- * use g++ conventions for virtual table */
-
- struct type *entry_type;
- /* First, get the virtual function table pointer. That comes
- with a strange type, so cast it to type `pointer to long' (which
- should serve just fine as a function type). Then, index into
- the table, and convert final value to appropriate function type. */
- value_ptr entry, vfn, vtbl;
- value_ptr vi = value_from_longest (builtin_type_int,
- (LONGEST) TYPE_FN_FIELD_VOFFSET (f, j));
- struct type *fcontext = TYPE_FN_FIELD_FCONTEXT (f, j);
- struct type *context;
- if (fcontext == NULL)
- /* We don't have an fcontext (e.g. the program was compiled with
- g++ version 1). Try to get the vtbl from the TYPE_VPTR_BASETYPE.
- This won't work right for multiple inheritance, but at least we
- should do as well as GDB 3.x did. */
- fcontext = TYPE_VPTR_BASETYPE (type);
- context = lookup_pointer_type (fcontext);
- /* Now context is a pointer to the basetype containing the vtbl. */
- if (TYPE_TARGET_TYPE (context) != type1)
- {
- value_ptr tmp = value_cast (context, value_addr (arg1));
- VALUE_POINTED_TO_OFFSET (tmp) = 0;
- arg1 = value_ind (tmp);
- type1 = check_typedef (VALUE_TYPE (arg1));
- }
-
- context = type1;
- /* Now context is the basetype containing the vtbl. */
-
- /* This type may have been defined before its virtual function table
- was. If so, fill in the virtual function table entry for the
- type now. */
- if (TYPE_VPTR_FIELDNO (context) < 0)
- fill_in_vptr_fieldno (context);
-
- /* The virtual function table is now an array of structures
- which have the form { int16 offset, delta; void *pfn; }. */
- vtbl = value_primitive_field (arg1, 0, TYPE_VPTR_FIELDNO (context),
- TYPE_VPTR_BASETYPE (context));
-
- /* With older versions of g++, the vtbl field pointed to an array
- of structures. Nowadays it points directly to the structure. */
- if (TYPE_CODE (VALUE_TYPE (vtbl)) == TYPE_CODE_PTR
- && TYPE_CODE (TYPE_TARGET_TYPE (VALUE_TYPE (vtbl))) == TYPE_CODE_ARRAY)
- {
- /* Handle the case where the vtbl field points to an
- array of structures. */
- vtbl = value_ind (vtbl);
-
- /* Index into the virtual function table. This is hard-coded because
- looking up a field is not cheap, and it may be important to save
- time, e.g. if the user has set a conditional breakpoint calling
- a virtual function. */
- entry = value_subscript (vtbl, vi);
- }
- else
- {
- /* Handle the case where the vtbl field points directly to a structure. */
- vtbl = value_add (vtbl, vi);
- entry = value_ind (vtbl);
- }
-
- entry_type = check_typedef (VALUE_TYPE (entry));
-
- if (TYPE_CODE (entry_type) == TYPE_CODE_STRUCT)
- {
- /* Move the `this' pointer according to the virtual function table. */
- VALUE_OFFSET (arg1) += value_as_long (value_field (entry, 0));
-
- if (!VALUE_LAZY (arg1))
- {
- VALUE_LAZY (arg1) = 1;
- value_fetch_lazy (arg1);
- }
-
- vfn = value_field (entry, 2);
- }
- else if (TYPE_CODE (entry_type) == TYPE_CODE_PTR)
- vfn = entry;
- else
- error ("I'm confused: virtual function table has bad type");
- /* Reinstantiate the function pointer with the correct type. */
- VALUE_TYPE (vfn) = lookup_pointer_type (TYPE_FN_FIELD_TYPE (f, j));
-
- *arg1p = arg1;
- return vfn;
- }
-}
-
-/* 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. */
-
-static value_ptr
-value_headof (in_arg, btype, dtype)
- value_ptr in_arg;
- struct type *btype, *dtype;
-{
- /* First collect the vtables we must look at for this object. */
- /* FIXME-tiemann: right now, just look at top-most vtable. */
- value_ptr arg, vtbl, entry, best_entry = 0;
- int i, nelems;
- int offset, best_offset = 0;
- struct symbol *sym;
- CORE_ADDR pc_for_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);
- vtbl = value_ind (value_field (value_ind (arg), TYPE_VPTR_FIELDNO (btype)));
-
- /* Check that VTBL looks like it points to a virtual function table. */
- msymbol = lookup_minimal_symbol_by_pc (VALUE_ADDRESS (vtbl));
- if (msymbol == NULL
- || (demangled_name = SYMBOL_NAME (msymbol)) == NULL
- || !VTBL_PREFIX_P (demangled_name))
projects / deliverable / binutils-gdb.git / blobdiff