+Fri Sep 4 00:34:30 1992 Per Bothner (bothner@rtl.cygnus.com)
+
+ A bunch of changes mostly to improve debugging of C++ programs.
+ Specifically, the calling of inferiors methods is improved.
+
+ * value.h: New macros METHOD_PTR_IS_VIRTUAL,
+ METHOD_PTR_FROM_VOFFSET, METHOD_PTR_TO_VOFFSET to partially
+ hide the implementation details of pointer-to-method objects.
+ How to tell if the pointer points to a virtual method is
+ still very dependent on the particular compiler, but this
+ should make it easier to find the places to change.
+ * eval.c (evaluate_subexp [case OP_FUNCALL]), valprint.c
+ (val_print [case TYPE_CODE_PTR]): Use the new METHOD_PTR_*
+ macros, instead of a hard-wired-in code that incorrectly
+ assumed a no-longerused representation of pointer-to-method
+ values. And otherwise fix the relevant bit-rotted code.
+
+ * valprint.c (type_print_base [case TYPE_CODE_STRUCT]):
+ If there are both fields and methods, put a space between.
+
+ * stabsread.c (read_struct_type): Fix bug in handling of
+ GNU C++ anonymous type (indicated by CPLUS_MARKER followed
+ by '_'). (It used to prematurely exit the loop reading in
+ the fields, so it would think it should start reading
+ methods while still in the fields. This could crash gdb
+ given a gcc that can emit nested type information.)
+
+ * valops.c (search_struct_method): Pass 'this' value by
+ reference instead of by value. This provides a more
+ consistent interface through a recursive search where the
+ "bottom" functions may need to adjust offsets (due to multiple
+ inheritance).
+ * valops.c, value.h, values.c: Pass extra parameters to
+ value_fn_field and value_virtual_fn_field so we can
+ correctly adjust offset for multiple inheritance.
+ * eval.c (evaluate_subexp [case OP_FUNCALL]): Simplify
+ virtual function calls by using value_virtual_fn_field().
+ * values.c: New function baseclass_offset, derived from
+ baseclass_addr (which perhaps can be made obsolete?).
+ It returns an offset rather than an address. This is a
+ cleaner interface since it doesn't mess around allocating
+ new values.
+ * valops.c (search_struct_method): Use baseclass_offset
+ rather than baseclass_addr.
+
Mon Oct 5 16:02:04 1992 Stu Grossman (grossman at cygnus.com)
* Makefile.in: Re-install 29K/UDI stuff.
J is an index into F which provides the desired method. */
value
-value_fn_field (f, j)
+value_fn_field (arg1p, f, j, type, offset)
+ value *arg1p;
struct fn_field *f;
int j;
+ struct type *type;
+ int offset;
{
register value v;
- register struct type *type = TYPE_FN_FIELD_TYPE (f, j);
+ register struct type *ftype = TYPE_FN_FIELD_TYPE (f, j);
struct symbol *sym;
sym = lookup_symbol (TYPE_FN_FIELD_PHYSNAME (f, j),
if (! sym) error ("Internal error: could not find physical method named %s",
TYPE_FN_FIELD_PHYSNAME (f, j));
- v = allocate_value (type);
+ v = allocate_value (ftype);
VALUE_ADDRESS (v) = BLOCK_START (SYMBOL_BLOCK_VALUE (sym));
- VALUE_TYPE (v) = type;
+ VALUE_TYPE (v) = ftype;
+
+ if (arg1p)
+ {
+ if (type != VALUE_TYPE (*arg1p))
+ *arg1p = value_ind (value_cast (lookup_pointer_type (type),
+ value_addr (*arg1p)));
+
+ /* Move the `this' pointer according to the offset. */
+ VALUE_OFFSET (*arg1p) += offset;
+ }
+
return v;
}
/* Return a virtual function as a value.
ARG1 is the object which provides the virtual function
- table pointer. ARG1 is side-effected in calling this function.
+ table pointer. *ARG1P is side-effected in calling this function.
F is the list of member functions which contains the desired virtual
function.
J is an index into F which provides the desired virtual function.
TYPE is the type in which F is located. */
value
-value_virtual_fn_field (arg1, f, j, type)
- value arg1;
+value_virtual_fn_field (arg1p, f, j, type, offset)
+ value *arg1p;
struct fn_field *f;
int j;
struct type *type;
+ int offset;
{
+ value arg1 = *arg1p;
/* 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 virtual function table is now an array of structures
which have the form { int16 offset, delta; void *pfn; }. */
- vtbl = value_ind (value_field (arg1, TYPE_VPTR_FIELDNO (context)));
+ vtbl = value_ind (value_primitive_field (arg1, 0,
+ TYPE_VPTR_FIELDNO (context),
+ TYPE_VPTR_BASETYPE (context)));
/* 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
entry = value_subscript (vtbl, vi);
/* Move the `this' pointer according to the virtual function table. */
- VALUE_OFFSET (arg1) += value_as_long (value_field (entry, 0));
+ VALUE_OFFSET (arg1) += value_as_long (value_field (entry, 0)) + offset;
if (! VALUE_LAZY (arg1))
{
VALUE_LAZY (arg1) = 1;
/* Reinstantiate the function pointer with the correct type. */
VALUE_TYPE (vfn) = lookup_pointer_type (TYPE_FN_FIELD_TYPE (f, j));
+ *arg1p = arg1;
return vfn;
}
return value_headof (arg, 0, type);
}
+/* Compute the offset of the baseclass which is
+ the INDEXth baseclass of class TYPE, for a value ARG,
+ wih extra offset of OFFSET.
+ The result is the offste of the baseclass value relative
+ to (the address of)(ARG) + OFFSET.
+
+ -1 is returned on error. */
+
+int
+baseclass_offset (type, index, arg, offset)
+ struct type *type;
+ int index;
+ value arg;
+ int offset;
+{
+ struct type *basetype = TYPE_BASECLASS (type, index);
+
+ if (BASETYPE_VIA_VIRTUAL (type, index))
+ {
+ /* Must hunt for the pointer to this virtual baseclass. */
+ register int i, len = TYPE_NFIELDS (type);
+ register int n_baseclasses = TYPE_N_BASECLASSES (type);
+ char *vbase_name, *type_name = type_name_no_tag (basetype);
+
+ vbase_name = (char *)alloca (strlen (type_name) + 8);
+ sprintf (vbase_name, "_vb%c%s", CPLUS_MARKER, type_name);
+ /* First look for the virtual baseclass pointer
+ in the fields. */
+ for (i = n_baseclasses; i < len; i++)
+ {
+ if (! strcmp (vbase_name, TYPE_FIELD_NAME (type, i)))
+ {
+ CORE_ADDR addr
+ = unpack_pointer (TYPE_FIELD_TYPE (type, i),
+ VALUE_CONTENTS (arg) + VALUE_OFFSET (arg)
+ + offset
+ + (TYPE_FIELD_BITPOS (type, i) / 8));
+
+ if (VALUE_LVAL (arg) != lval_memory)
+ return -1;
+
+ return addr -
+ (LONGEST) (VALUE_ADDRESS (arg) + VALUE_OFFSET (arg) + offset);
+ }
+ }
+ /* Not in the fields, so try looking through the baseclasses. */
+ for (i = index+1; i < n_baseclasses; i++)
+ {
+ int boffset =
+ baseclass_offset (type, i, arg, offset);
+ if (boffset)
+ return boffset;
+ }
+ /* Not found. */
+ return -1;
+ }
+
+ /* Baseclass is easily computed. */
+ return TYPE_BASECLASS_BITPOS (type, index) / 8;
+}
+
/* Compute the address of the baseclass which is
the INDEXth baseclass of class TYPE. The TYPE base
of the object is at VALADDR.
of the baseclasss, but the address which could not be read
successfully. */
+/* FIXME Fix remaining uses of baseclass_addr to use baseclass_offset */
+
char *
baseclass_addr (type, index, valaddr, valuep, errp)
struct type *type;
projects / deliverable / binutils-gdb.git / commitdiff
