- /* Deal with HP/Taligent runtime model for virtual functions */
- value_ptr vp;
- value_ptr argp; /* arg1 cast to base */
- CORE_ADDR vfunc_addr; /* address of virtual method */
- CORE_ADDR coreptr; /* pointer to target address */
- int class_index; /* which class segment pointer to use */
- struct type * ftype = TYPE_FN_FIELD_TYPE (f, j); /* method type */
-
- argp = value_cast (type, *arg1p);
-
- if (VALUE_ADDRESS (argp) == 0)
- error ("Address of object is null; object may not have been created.");
-
- /* pai: FIXME -- 32x64 possible problem? */
- /* First word (4 bytes) in object layout is the vtable pointer */
- coreptr = * (CORE_ADDR *) (VALUE_CONTENTS (argp)); /* pai: (temp) */
- /* + offset + VALUE_EMBEDDED_OFFSET (argp)); */
-
- if (!coreptr)
- error ("Virtual table pointer is null for object; object may not have been created.");
-
- /* pai/1997-05-09
- * FIXME: The code here currently handles only
- * the non-RRBC case of the Taligent/HP runtime spec; when RRBC
- * is introduced, the condition for the "if" below will have to
- * be changed to be a test for the RRBC case. */
-
- if (1)
- {
- /* Non-RRBC case; the virtual function pointers are stored at fixed
- * offsets in the virtual table. */
-
- /* Retrieve the offset in the virtual table from the debug
- * info. The offset of the vfunc's entry is in words from
- * the beginning of the vtable; but first we have to adjust
- * by HP_ACC_VFUNC_START to account for other entries */
-
- /* pai: FIXME: 32x64 problem here, a word may be 8 bytes in
- * which case the multiplier should be 8 and values should be long */
- vp = value_at (builtin_type_int,
- coreptr + 4 * (TYPE_FN_FIELD_VOFFSET (f, j) + HP_ACC_VFUNC_START), NULL);
-
- coreptr = * (CORE_ADDR *) (VALUE_CONTENTS (vp));
- /* coreptr now contains the address of the virtual function */
- /* (Actually, it contains the pointer to the plabel for the function. */
- }
- else
- {
- /* RRBC case; the virtual function pointers are found by double
- * indirection through the class segment tables. */
-
- /* Choose class segment depending on type we were passed */
- class_index = class_index_in_primary_list (type);
-
- /* Find class segment pointer. These are in the vtable slots after
- * some other entries, so adjust by HP_ACC_VFUNC_START for that. */
- /* pai: FIXME 32x64 problem here, if words are 8 bytes long
- * the multiplier below has to be 8 and value should be long. */
- vp = value_at (builtin_type_int,
- coreptr + 4 * (HP_ACC_VFUNC_START + class_index), NULL);
- /* Indirect once more, offset by function index */
- /* pai: FIXME 32x64 problem here, again multiplier could be 8 and value long */
- coreptr = * (CORE_ADDR *) (VALUE_CONTENTS (vp) + 4 * TYPE_FN_FIELD_VOFFSET (f, j));
- vp = value_at (builtin_type_int, coreptr, NULL);
- coreptr = * (CORE_ADDR *) (VALUE_CONTENTS (vp));
-
- /* coreptr now contains the address of the virtual function */
- /* (Actually, it contains the pointer to the plabel for the function.) */
-
- }
-
- if (!coreptr)
- error ("Address of virtual function is null; error in virtual table?");
-
- /* Wrap this addr in a value and return pointer */
- vp = allocate_value (ftype);
- VALUE_TYPE (vp) = ftype;
- VALUE_ADDRESS (vp) = coreptr;
-
- /* pai: (temp) do we need the value_ind stuff in value_fn_field? */
- return vp;
- }
- else
- { /* 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;
projects / deliverable / binutils-gdb.git / blobdiff