/* Abstraction of GNU v3 abi.
Contributed by Jim Blandy <jimb@redhat.com>
- Copyright 2001, 2002, 2003, 2005 Free Software Foundation, Inc.
+ Copyright (C) 2001, 2002, 2003, 2005, 2006, 2007
+ Free Software Foundation, Inc.
This file is part of GDB.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
- Foundation, Inc., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA. */
+ Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ Boston, MA 02110-1301, USA. */
#include "defs.h"
#include "value.h"
#include "cp-abi.h"
#include "cp-support.h"
#include "demangle.h"
+#include "objfiles.h"
+#include "valprint.h"
+
#include "gdb_assert.h"
#include "gdb_string.h"
/* ARCH can't give us the true ptrdiff_t type, so we guess. */
struct type *ptrdiff_type
- = init_type (TYPE_CODE_INT, TARGET_PTR_BIT / TARGET_CHAR_BIT, 0,
+ = init_type (TYPE_CODE_INT,
+ gdbarch_ptr_bit (current_gdbarch) / TARGET_CHAR_BIT, 0,
"ptrdiff_t", 0);
/* We assume no padding is necessary, since GDB doesn't know
vtable_symbol
= lookup_minimal_symbol_by_pc (VALUE_ADDRESS (vtable)
+ value_offset (vtable)
- + VALUE_EMBEDDED_OFFSET (vtable));
+ + value_embedded_offset (vtable));
if (! vtable_symbol)
return NULL;
if (vtable_symbol_name == NULL
|| strncmp (vtable_symbol_name, "vtable for ", 11))
{
- warning ("can't find linker symbol for virtual table for `%s' value",
+ warning (_("can't find linker symbol for virtual table for `%s' value"),
TYPE_NAME (values_type));
if (vtable_symbol_name)
- warning (" found `%s' instead", vtable_symbol_name);
+ warning (_(" found `%s' instead"), vtable_symbol_name);
return NULL;
}
class_name = vtable_symbol_name + 11;
= value_as_long (value_field (vtable, vtable_field_offset_to_top));
if (full_p)
- *full_p = (- offset_to_top == VALUE_EMBEDDED_OFFSET (value)
+ *full_p = (- offset_to_top == value_embedded_offset (value)
&& (TYPE_LENGTH (value_enclosing_type (value))
>= TYPE_LENGTH (run_time_type)));
if (top_p)
return run_time_type;
}
+/* Find the vtable for CONTAINER and return a value of the correct
+ vtable type for this architecture. */
static struct value *
-gnuv3_virtual_fn_field (struct value **value_p,
- struct fn_field *f, int j,
- struct type *type, int offset)
+gnuv3_get_vtable (struct value *container)
{
struct type *vtable_type = gdbarch_data (current_gdbarch,
vtable_type_gdbarch_data);
- struct value *value = *value_p;
- struct type *values_type = check_typedef (value_type (value));
- struct type *vfn_base;
- CORE_ADDR vtable_address;
- struct value *vtable;
- struct value *vfn;
+ struct type *vtable_pointer_type;
+ struct value *vtable_pointer;
+ CORE_ADDR vtable_pointer_address, vtable_address;
+
+ /* We do not consult the debug information to find the virtual table.
+ The ABI specifies that it is always at offset zero in any class,
+ and debug information may not represent it. We won't issue an
+ error if there's a class with virtual functions but no virtual table
+ pointer, but something's already gone seriously wrong if that
+ happens.
+
+ We avoid using value_contents on principle, because the object might
+ be large. */
+
+ /* Find the type "pointer to virtual table". */
+ vtable_pointer_type = lookup_pointer_type (vtable_type);
+
+ /* Load it from the start of the class. */
+ vtable_pointer_address = value_as_address (value_addr (container));
+ vtable_pointer = value_at (vtable_pointer_type, vtable_pointer_address);
+ vtable_address = value_as_address (vtable_pointer);
+
+ /* Correct it to point at the start of the virtual table, rather
+ than the address point. */
+ return value_at_lazy (vtable_type,
+ vtable_address - vtable_address_point_offset ());
+}
- /* Some simple sanity checks. */
- if (TYPE_CODE (values_type) != TYPE_CODE_CLASS)
- error ("Only classes can have virtual functions.");
-
- /* Find the base class that defines this virtual function. */
- vfn_base = TYPE_FN_FIELD_FCONTEXT (f, j);
- if (! vfn_base)
- /* In programs compiled with G++ version 1, the debug info doesn't
- say which base class defined the virtual function. We'll guess
- it's the same base class that has our vtable; this is wrong for
- multiple inheritance, but it's better than nothing. */
- vfn_base = TYPE_VPTR_BASETYPE (type);
-
- /* 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 (vfn_base) < 0)
- fill_in_vptr_fieldno (vfn_base);
- if (TYPE_VPTR_FIELDNO (vfn_base) < 0)
- error ("Could not find virtual table pointer for class \"%s\".",
- TYPE_TAG_NAME (vfn_base) ? TYPE_TAG_NAME (vfn_base) : "<unknown>");
-
- /* Now that we know which base class is defining our virtual
- function, cast our value to that baseclass. This takes care of
- any necessary `this' adjustments. */
- if (vfn_base != values_type)
- value = value_cast (vfn_base, value);
-
- /* Now value is an object of the appropriate base type. Fetch its
- virtual table. */
- /* It might be possible to do this cast at the same time as the above.
- Does multiple inheritance affect this?
- Can this even trigger, or is TYPE_VPTR_BASETYPE idempotent?
- */
- if (TYPE_VPTR_BASETYPE (vfn_base) != vfn_base)
- value = value_cast (TYPE_VPTR_BASETYPE (vfn_base), value);
- vtable_address
- = value_as_address (value_field (value, TYPE_VPTR_FIELDNO (vfn_base)));
+/* Return a function pointer for CONTAINER's VTABLE_INDEX'th virtual
+ function, of type FNTYPE. */
- vtable = value_at_lazy (vtable_type,
- vtable_address - vtable_address_point_offset ());
+static struct value *
+gnuv3_get_virtual_fn (struct value *container, struct type *fntype,
+ int vtable_index)
+{
+ struct value *vtable = gnuv3_get_vtable (container);
+ struct value *vfn;
/* Fetch the appropriate function pointer from the vtable. */
vfn = value_subscript (value_field (vtable, vtable_field_virtual_functions),
- value_from_longest (builtin_type_int,
- TYPE_FN_FIELD_VOFFSET (f, j)));
+ value_from_longest (builtin_type_int, vtable_index));
- /* Cast the function pointer to the appropriate type. */
- vfn = value_cast (lookup_pointer_type (TYPE_FN_FIELD_TYPE (f, j)),
- vfn);
+ /* If this architecture uses function descriptors directly in the vtable,
+ then the address of the vtable entry is actually a "function pointer"
+ (i.e. points to the descriptor). We don't need to scale the index
+ by the size of a function descriptor; GCC does that before outputing
+ debug information. */
+ if (gdbarch_vtable_function_descriptors (current_gdbarch))
+ vfn = value_addr (vfn);
- /* Is (type)value always numerically the same as (vfn_base)value?
- If so we can spare this cast and use one of the ones above. */
- *value_p = value_addr (value_cast (type, *value_p));
+ /* Cast the function pointer to the appropriate type. */
+ vfn = value_cast (lookup_pointer_type (fntype), vfn);
return vfn;
}
+/* GNU v3 implementation of value_virtual_fn_field. See cp-abi.h
+ for a description of the arguments. */
+
+static struct value *
+gnuv3_virtual_fn_field (struct value **value_p,
+ struct fn_field *f, int j,
+ struct type *vfn_base, int offset)
+{
+ struct type *values_type = check_typedef (value_type (*value_p));
+
+ /* Some simple sanity checks. */
+ if (TYPE_CODE (values_type) != TYPE_CODE_CLASS)
+ error (_("Only classes can have virtual functions."));
+
+ /* Cast our value to the base class which defines this virtual
+ function. This takes care of any necessary `this'
+ adjustments. */
+ if (vfn_base != values_type)
+ *value_p = value_cast (vfn_base, *value_p);
+
+ return gnuv3_get_virtual_fn (*value_p, TYPE_FN_FIELD_TYPE (f, j),
+ TYPE_FN_FIELD_VOFFSET (f, j));
+}
+
/* Compute the offset of the baseclass which is
the INDEXth baseclass of class TYPE,
for value at VALADDR (in host) at ADDRESS (in target).
-1 is returned on error. */
static int
-gnuv3_baseclass_offset (struct type *type, int index, char *valaddr,
+gnuv3_baseclass_offset (struct type *type, int index, const bfd_byte *valaddr,
CORE_ADDR address)
{
struct type *vtable_type = gdbarch_data (current_gdbarch,
worthwhile. */
cur_base_offset = TYPE_BASECLASS_BITPOS (type, index) / 8;
if (cur_base_offset >= - vtable_address_point_offset ())
- error ("Expected a negative vbase offset (old compiler?)");
+ error (_("Expected a negative vbase offset (old compiler?)"));
cur_base_offset = cur_base_offset + vtable_address_point_offset ();
if ((- cur_base_offset) % TYPE_LENGTH (builtin_type_void_data_ptr) != 0)
- error ("Misaligned vbase offset.");
+ error (_("Misaligned vbase offset."));
cur_base_offset = cur_base_offset
/ ((int) TYPE_LENGTH (builtin_type_void_data_ptr));
if (TYPE_VPTR_FIELDNO (vbasetype) >= 0
&& TYPE_FIELD_BITPOS (vbasetype, TYPE_VPTR_FIELDNO (vbasetype)) != 0)
- error ("Illegal vptr offset in class %s",
+ error (_("Illegal vptr offset in class %s"),
TYPE_NAME (vbasetype) ? TYPE_NAME (vbasetype) : "<unknown>");
vtable_address = value_as_address (value_at_lazy (builtin_type_void_data_ptr,
return base_offset;
}
+/* Locate a virtual method in DOMAIN or its non-virtual base classes
+ which has virtual table index VOFFSET. The method has an associated
+ "this" adjustment of ADJUSTMENT bytes. */
+
+const char *
+gnuv3_find_method_in (struct type *domain, CORE_ADDR voffset,
+ LONGEST adjustment)
+{
+ int i;
+ const char *physname;
+
+ /* Search this class first. */
+ physname = NULL;
+ if (adjustment == 0)
+ {
+ int len;
+
+ len = TYPE_NFN_FIELDS (domain);
+ for (i = 0; i < len; i++)
+ {
+ int len2, j;
+ struct fn_field *f;
+
+ f = TYPE_FN_FIELDLIST1 (domain, i);
+ len2 = TYPE_FN_FIELDLIST_LENGTH (domain, i);
+
+ check_stub_method_group (domain, i);
+ for (j = 0; j < len2; j++)
+ if (TYPE_FN_FIELD_VOFFSET (f, j) == voffset)
+ return TYPE_FN_FIELD_PHYSNAME (f, j);
+ }
+ }
+
+ /* Next search non-virtual bases. If it's in a virtual base,
+ we're out of luck. */
+ for (i = 0; i < TYPE_N_BASECLASSES (domain); i++)
+ {
+ int pos;
+ struct type *basetype;
+
+ if (BASETYPE_VIA_VIRTUAL (domain, i))
+ continue;
+
+ pos = TYPE_BASECLASS_BITPOS (domain, i) / 8;
+ basetype = TYPE_FIELD_TYPE (domain, i);
+ /* Recurse with a modified adjustment. We don't need to adjust
+ voffset. */
+ if (adjustment >= pos && adjustment < pos + TYPE_LENGTH (basetype))
+ return gnuv3_find_method_in (basetype, voffset, adjustment - pos);
+ }
+
+ return NULL;
+}
+
+/* GNU v3 implementation of cplus_print_method_ptr. */
+
+static void
+gnuv3_print_method_ptr (const gdb_byte *contents,
+ struct type *type,
+ struct ui_file *stream)
+{
+ CORE_ADDR ptr_value;
+ LONGEST adjustment;
+ struct type *domain;
+ int vbit;
+
+ domain = TYPE_DOMAIN_TYPE (type);
+
+ /* Extract the pointer to member. */
+ ptr_value = extract_typed_address (contents, builtin_type_void_func_ptr);
+ contents += TYPE_LENGTH (builtin_type_void_func_ptr);
+ adjustment = extract_signed_integer (contents,
+ TYPE_LENGTH (builtin_type_long));
+
+ if (!gdbarch_vbit_in_delta (current_gdbarch))
+ {
+ vbit = ptr_value & 1;
+ ptr_value = ptr_value ^ vbit;
+ }
+ else
+ {
+ vbit = adjustment & 1;
+ adjustment = adjustment >> 1;
+ }
+
+ /* Check for NULL. */
+ if (ptr_value == 0 && vbit == 0)
+ {
+ fprintf_filtered (stream, "NULL");
+ return;
+ }
+
+ /* Search for a virtual method. */
+ if (vbit)
+ {
+ CORE_ADDR voffset;
+ const char *physname;
+
+ /* It's a virtual table offset, maybe in this class. Search
+ for a field with the correct vtable offset. First convert it
+ to an index, as used in TYPE_FN_FIELD_VOFFSET. */
+ voffset = ptr_value / TYPE_LENGTH (builtin_type_long);
+
+ physname = gnuv3_find_method_in (domain, voffset, adjustment);
+
+ /* If we found a method, print that. We don't bother to disambiguate
+ possible paths to the method based on the adjustment. */
+ if (physname)
+ {
+ char *demangled_name = cplus_demangle (physname,
+ DMGL_ANSI | DMGL_PARAMS);
+ if (demangled_name != NULL)
+ {
+ fprintf_filtered (stream, "&virtual ");
+ fputs_filtered (demangled_name, stream);
+ xfree (demangled_name);
+ return;
+ }
+ }
+ }
+
+ /* We didn't find it; print the raw data. */
+ if (vbit)
+ {
+ fprintf_filtered (stream, "&virtual table offset ");
+ print_longest (stream, 'd', 1, ptr_value);
+ }
+ else
+ print_address_demangle (ptr_value, stream, demangle);
+
+ if (adjustment)
+ {
+ fprintf_filtered (stream, ", this adjustment ");
+ print_longest (stream, 'd', 1, adjustment);
+ }
+}
+
+/* GNU v3 implementation of cplus_method_ptr_size. */
+
+static int
+gnuv3_method_ptr_size (void)
+{
+ return 2 * TYPE_LENGTH (builtin_type_void_data_ptr);
+}
+
+/* GNU v3 implementation of cplus_make_method_ptr. */
+
+static void
+gnuv3_make_method_ptr (gdb_byte *contents, CORE_ADDR value, int is_virtual)
+{
+ int size = TYPE_LENGTH (builtin_type_void_data_ptr);
+
+ /* FIXME drow/2006-12-24: The adjustment of "this" is currently
+ always zero, since the method pointer is of the correct type.
+ But if the method pointer came from a base class, this is
+ incorrect - it should be the offset to the base. The best
+ fix might be to create the pointer to member pointing at the
+ base class and cast it to the derived class, but that requires
+ support for adjusting pointers to members when casting them -
+ not currently supported by GDB. */
+
+ if (!gdbarch_vbit_in_delta (current_gdbarch))
+ {
+ store_unsigned_integer (contents, size, value | is_virtual);
+ store_unsigned_integer (contents + size, size, 0);
+ }
+ else
+ {
+ store_unsigned_integer (contents, size, value);
+ store_unsigned_integer (contents + size, size, is_virtual);
+ }
+}
+
+/* GNU v3 implementation of cplus_method_ptr_to_value. */
+
+static struct value *
+gnuv3_method_ptr_to_value (struct value **this_p, struct value *method_ptr)
+{
+ const gdb_byte *contents = value_contents (method_ptr);
+ CORE_ADDR ptr_value;
+ struct type *final_type, *method_type;
+ LONGEST adjustment;
+ struct value *adjval;
+ int vbit;
+
+ final_type = TYPE_DOMAIN_TYPE (check_typedef (value_type (method_ptr)));
+ final_type = lookup_pointer_type (final_type);
+
+ method_type = TYPE_TARGET_TYPE (check_typedef (value_type (method_ptr)));
+
+ ptr_value = extract_typed_address (contents, builtin_type_void_func_ptr);
+ contents += TYPE_LENGTH (builtin_type_void_func_ptr);
+ adjustment = extract_signed_integer (contents,
+ TYPE_LENGTH (builtin_type_long));
+
+ if (!gdbarch_vbit_in_delta (current_gdbarch))
+ {
+ vbit = ptr_value & 1;
+ ptr_value = ptr_value ^ vbit;
+ }
+ else
+ {
+ vbit = adjustment & 1;
+ adjustment = adjustment >> 1;
+ }
+
+ /* First convert THIS to match the containing type of the pointer to
+ member. This cast may adjust the value of THIS. */
+ *this_p = value_cast (final_type, *this_p);
+
+ /* Then apply whatever adjustment is necessary. This creates a somewhat
+ strange pointer: it claims to have type FINAL_TYPE, but in fact it
+ might not be a valid FINAL_TYPE. For instance, it might be a
+ base class of FINAL_TYPE. And if it's not the primary base class,
+ then printing it out as a FINAL_TYPE object would produce some pretty
+ garbage.
+
+ But we don't really know the type of the first argument in
+ METHOD_TYPE either, which is why this happens. We can't
+ dereference this later as a FINAL_TYPE, but once we arrive in the
+ called method we'll have debugging information for the type of
+ "this" - and that'll match the value we produce here.
+
+ You can provoke this case by casting a Base::* to a Derived::*, for
+ instance. */
+ *this_p = value_cast (builtin_type_void_data_ptr, *this_p);
+ adjval = value_from_longest (builtin_type_long, adjustment);
+ *this_p = value_add (*this_p, adjval);
+ *this_p = value_cast (final_type, *this_p);
+
+ if (vbit)
+ {
+ LONGEST voffset = ptr_value / TYPE_LENGTH (builtin_type_long);
+ return gnuv3_get_virtual_fn (value_ind (*this_p), method_type, voffset);
+ }
+ else
+ return value_from_pointer (lookup_pointer_type (method_type), ptr_value);
+}
+
+/* Determine if we are currently in a C++ thunk. If so, get the address
+ of the routine we are thunking to and continue to there instead. */
+
+static CORE_ADDR
+gnuv3_skip_trampoline (struct frame_info *frame, CORE_ADDR stop_pc)
+{
+ CORE_ADDR real_stop_pc, method_stop_pc;
+ struct minimal_symbol *thunk_sym, *fn_sym;
+ struct obj_section *section;
+ char *thunk_name, *fn_name;
+
+ real_stop_pc = gdbarch_skip_trampoline_code
+ (current_gdbarch, frame, stop_pc);
+ if (real_stop_pc == 0)
+ real_stop_pc = stop_pc;
+
+ /* Find the linker symbol for this potential thunk. */
+ thunk_sym = lookup_minimal_symbol_by_pc (real_stop_pc);
+ section = find_pc_section (real_stop_pc);
+ if (thunk_sym == NULL || section == NULL)
+ return 0;
+
+ /* The symbol's demangled name should be something like "virtual
+ thunk to FUNCTION", where FUNCTION is the name of the function
+ being thunked to. */
+ thunk_name = SYMBOL_DEMANGLED_NAME (thunk_sym);
+ if (thunk_name == NULL || strstr (thunk_name, " thunk to ") == NULL)
+ return 0;
+
+ fn_name = strstr (thunk_name, " thunk to ") + strlen (" thunk to ");
+ fn_sym = lookup_minimal_symbol (fn_name, NULL, section->objfile);
+ if (fn_sym == NULL)
+ return 0;
+
+ method_stop_pc = SYMBOL_VALUE_ADDRESS (fn_sym);
+ real_stop_pc = gdbarch_skip_trampoline_code
+ (current_gdbarch, frame, method_stop_pc);
+ if (real_stop_pc == 0)
+ real_stop_pc = method_stop_pc;
+
+ return real_stop_pc;
+}
+
static void
init_gnuv3_ops (void)
{
gnu_v3_abi_ops.shortname = "gnu-v3";
gnu_v3_abi_ops.longname = "GNU G++ Version 3 ABI";
gnu_v3_abi_ops.doc = "G++ Version 3 ABI";
- gnu_v3_abi_ops.is_destructor_name = is_gnu_v3_mangled_dtor;
- gnu_v3_abi_ops.is_constructor_name = is_gnu_v3_mangled_ctor;
+ gnu_v3_abi_ops.is_destructor_name =
+ (enum dtor_kinds (*) (const char *))is_gnu_v3_mangled_dtor;
+ gnu_v3_abi_ops.is_constructor_name =
+ (enum ctor_kinds (*) (const char *))is_gnu_v3_mangled_ctor;
gnu_v3_abi_ops.is_vtable_name = gnuv3_is_vtable_name;
gnu_v3_abi_ops.is_operator_name = gnuv3_is_operator_name;
gnu_v3_abi_ops.rtti_type = gnuv3_rtti_type;
gnu_v3_abi_ops.virtual_fn_field = gnuv3_virtual_fn_field;
gnu_v3_abi_ops.baseclass_offset = gnuv3_baseclass_offset;
+ gnu_v3_abi_ops.print_method_ptr = gnuv3_print_method_ptr;
+ gnu_v3_abi_ops.method_ptr_size = gnuv3_method_ptr_size;
+ gnu_v3_abi_ops.make_method_ptr = gnuv3_make_method_ptr;
+ gnu_v3_abi_ops.method_ptr_to_value = gnuv3_method_ptr_to_value;
+ gnu_v3_abi_ops.skip_trampoline = gnuv3_skip_trampoline;
}
extern initialize_file_ftype _initialize_gnu_v3_abi; /* -Wmissing-prototypes */
projects / deliverable / binutils-gdb.git / blobdiff