/* 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, 2008, 2009, 2010, 2011
+ Free Software Foundation, Inc.
This file is part of GDB.
- This program is free software; you can redistribute it and/or
- modify it under the terms of the GNU General Public License as
- published by the Free Software Foundation; either version 2 of the
- License, or (at your option) any later version.
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
GNU General Public License for more details.
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. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
#include "value.h"
#include "cp-abi.h"
#include "cp-support.h"
#include "demangle.h"
+#include "objfiles.h"
+#include "valprint.h"
+#include "c-lang.h"
+
#include "gdb_assert.h"
#include "gdb_string.h"
described above, laid out appropriately for ARCH.
We use this function as the gdbarch per-architecture data
- initialization function. We assume that the gdbarch framework
- calls the per-architecture data initialization functions after it
- sets current_gdbarch to the new architecture. */
+ initialization function. */
static void *
build_gdb_vtable_type (struct gdbarch *arch)
{
int offset;
struct type *void_ptr_type
- = lookup_pointer_type (builtin_type_void);
+ = builtin_type (arch)->builtin_data_ptr;
struct type *ptr_to_void_fn_type
- = lookup_pointer_type (lookup_function_type (builtin_type_void));
+ = builtin_type (arch)->builtin_func_ptr;
/* 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,
- "ptrdiff_t", 0);
+ = arch_integer_type (arch, gdbarch_ptr_bit (arch), 0, "ptrdiff_t");
/* We assume no padding is necessary, since GDB doesn't know
anything about alignment at the moment. If this assumption bites
/* ptrdiff_t vcall_and_vbase_offsets[0]; */
FIELD_NAME (*field) = "vcall_and_vbase_offsets";
- FIELD_TYPE (*field)
- = create_array_type (0, ptrdiff_type,
- create_range_type (0, builtin_type_int, 0, -1));
+ FIELD_TYPE (*field) = lookup_array_range_type (ptrdiff_type, 0, -1);
FIELD_BITPOS (*field) = offset * TARGET_CHAR_BIT;
offset += TYPE_LENGTH (FIELD_TYPE (*field));
field++;
/* void (*virtual_functions[0]) (); */
FIELD_NAME (*field) = "virtual_functions";
- FIELD_TYPE (*field)
- = create_array_type (0, ptr_to_void_fn_type,
- create_range_type (0, builtin_type_int, 0, -1));
+ FIELD_TYPE (*field) = lookup_array_range_type (ptr_to_void_fn_type, 0, -1);
FIELD_BITPOS (*field) = offset * TARGET_CHAR_BIT;
offset += TYPE_LENGTH (FIELD_TYPE (*field));
field++;
/* We assumed in the allocation above that there were four fields. */
gdb_assert (field == (field_list + 4));
- t = init_type (TYPE_CODE_STRUCT, offset, 0, 0, 0);
+ t = arch_type (arch, TYPE_CODE_STRUCT, offset, NULL);
TYPE_NFIELDS (t) = field - field_list;
TYPE_FIELDS (t) = field_list;
TYPE_TAG_NAME (t) = "gdb_gnu_v3_abi_vtable";
+ INIT_CPLUS_SPECIFIC (t);
return t;
}
+/* Return the ptrdiff_t type used in the vtable type. */
+static struct type *
+vtable_ptrdiff_type (struct gdbarch *gdbarch)
+{
+ struct type *vtable_type = gdbarch_data (gdbarch, vtable_type_gdbarch_data);
+
+ /* The "offset_to_top" field has the appropriate (ptrdiff_t) type. */
+ return TYPE_FIELD_TYPE (vtable_type, vtable_field_offset_to_top);
+}
+
/* Return the offset from the start of the imaginary `struct
gdb_gnu_v3_abi_vtable' object to the vtable's "address point"
(i.e., where objects' virtual table pointers point). */
static int
-vtable_address_point_offset (void)
+vtable_address_point_offset (struct gdbarch *gdbarch)
{
- struct type *vtable_type = gdbarch_data (current_gdbarch,
- vtable_type_gdbarch_data);
+ struct type *vtable_type = gdbarch_data (gdbarch, vtable_type_gdbarch_data);
return (TYPE_FIELD_BITPOS (vtable_type, vtable_field_virtual_functions)
/ TARGET_CHAR_BIT);
}
+/* Determine whether structure TYPE is a dynamic class. Cache the
+ result. */
+
+static int
+gnuv3_dynamic_class (struct type *type)
+{
+ int fieldnum, fieldelem;
+
+ if (TYPE_CPLUS_DYNAMIC (type))
+ return TYPE_CPLUS_DYNAMIC (type) == 1;
+
+ ALLOCATE_CPLUS_STRUCT_TYPE (type);
+
+ for (fieldnum = 0; fieldnum < TYPE_N_BASECLASSES (type); fieldnum++)
+ if (BASETYPE_VIA_VIRTUAL (type, fieldnum)
+ || gnuv3_dynamic_class (TYPE_FIELD_TYPE (type, fieldnum)))
+ {
+ TYPE_CPLUS_DYNAMIC (type) = 1;
+ return 1;
+ }
+
+ for (fieldnum = 0; fieldnum < TYPE_NFN_FIELDS (type); fieldnum++)
+ for (fieldelem = 0; fieldelem < TYPE_FN_FIELDLIST_LENGTH (type, fieldnum);
+ fieldelem++)
+ {
+ struct fn_field *f = TYPE_FN_FIELDLIST1 (type, fieldnum);
+
+ if (TYPE_FN_FIELD_VIRTUAL_P (f, fieldelem))
+ {
+ TYPE_CPLUS_DYNAMIC (type) = 1;
+ return 1;
+ }
+ }
+
+ TYPE_CPLUS_DYNAMIC (type) = -1;
+ return 0;
+}
+
+/* Find the vtable for a value of CONTAINER_TYPE located at
+ CONTAINER_ADDR. Return a value of the correct vtable type for this
+ architecture, or NULL if CONTAINER does not have a vtable. */
+
+static struct value *
+gnuv3_get_vtable (struct gdbarch *gdbarch,
+ struct type *container_type, CORE_ADDR container_addr)
+{
+ struct type *vtable_type = gdbarch_data (gdbarch,
+ vtable_type_gdbarch_data);
+ struct type *vtable_pointer_type;
+ struct value *vtable_pointer;
+ CORE_ADDR vtable_address;
+
+ /* If this type does not have a virtual table, don't read the first
+ field. */
+ if (!gnuv3_dynamic_class (check_typedef (container_type)))
+ return NULL;
+
+ /* 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 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 = value_at (vtable_pointer_type, container_addr);
+ 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 (gdbarch));
+}
+
+
static struct type *
gnuv3_rtti_type (struct value *value,
int *full_p, int *top_p, int *using_enc_p)
{
- struct type *vtable_type = gdbarch_data (current_gdbarch,
- vtable_type_gdbarch_data);
+ struct gdbarch *gdbarch;
struct type *values_type = check_typedef (value_type (value));
- CORE_ADDR vtable_address;
struct value *vtable;
struct minimal_symbol *vtable_symbol;
const char *vtable_symbol_name;
const char *class_name;
struct type *run_time_type;
- struct type *base_type;
LONGEST offset_to_top;
/* We only have RTTI for class objects. */
if (TYPE_CODE (values_type) != TYPE_CODE_CLASS)
return NULL;
- /* If we can't find the virtual table pointer for values_type, we
- can't find the RTTI. */
- fill_in_vptr_fieldno (values_type);
- if (TYPE_VPTR_FIELDNO (values_type) == -1)
+ /* Java doesn't have RTTI following the C++ ABI. */
+ if (TYPE_CPLUS_REALLY_JAVA (values_type))
return NULL;
+ /* Determine architecture. */
+ gdbarch = get_type_arch (values_type);
+
if (using_enc_p)
*using_enc_p = 0;
- /* Fetch VALUE's virtual table pointer, and tweak it to point at
- an instance of our imaginary gdb_gnu_v3_abi_vtable structure. */
- base_type = check_typedef (TYPE_VPTR_BASETYPE (values_type));
- if (values_type != base_type)
- {
- value = value_cast (base_type, value);
- if (using_enc_p)
- *using_enc_p = 1;
- }
- vtable_address
- = value_as_address (value_field (value, TYPE_VPTR_FIELDNO (values_type)));
- vtable = value_at_lazy (vtable_type,
- vtable_address - vtable_address_point_offset ());
-
+ vtable = gnuv3_get_vtable (gdbarch, value_type (value),
+ value_as_address (value_addr (value)));
+ if (vtable == NULL)
+ return NULL;
+
/* Find the linker symbol for this vtable. */
vtable_symbol
- = lookup_minimal_symbol_by_pc (VALUE_ADDRESS (vtable)
- + value_offset (vtable)
+ = lookup_minimal_symbol_by_pc (value_address (vtable)
+ value_embedded_offset (vtable));
if (! vtable_symbol)
return NULL;
class_name = vtable_symbol_name + 11;
/* Try to look up the class name as a type name. */
- /* FIXME: chastain/2003-11-26: block=NULL is bogus. See pr gdb/1465. */
+ /* FIXME: chastain/2003-11-26: block=NULL is bogus. See pr gdb/1465. */
run_time_type = cp_lookup_rtti_type (class_name, NULL);
if (run_time_type == NULL)
return NULL;
>= TYPE_LENGTH (run_time_type)));
if (top_p)
*top_p = - offset_to_top;
-
return run_time_type;
}
+/* Return a function pointer for CONTAINER's VTABLE_INDEX'th virtual
+ function, of type FNTYPE. */
+
+static struct value *
+gnuv3_get_virtual_fn (struct gdbarch *gdbarch, struct value *container,
+ struct type *fntype, int vtable_index)
+{
+ struct value *vtable, *vfn;
+
+ /* Every class with virtual functions must have a vtable. */
+ vtable = gnuv3_get_vtable (gdbarch, value_type (container),
+ value_as_address (value_addr (container)));
+ gdb_assert (vtable != NULL);
+
+ /* Fetch the appropriate function pointer from the vtable. */
+ vfn = value_subscript (value_field (vtable, vtable_field_virtual_functions),
+ vtable_index);
+
+ /* 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 (gdbarch))
+ vfn = value_addr (vfn);
+
+ /* 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 *type, int offset)
+ struct type *vfn_base, int offset)
{
- 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 *values_type = check_typedef (value_type (*value_p));
+ struct gdbarch *gdbarch;
/* 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)));
-
- vtable = value_at_lazy (vtable_type,
- vtable_address - vtable_address_point_offset ());
+ /* Determine architecture. */
+ gdbarch = get_type_arch (values_type);
- /* 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)));
-
- /* Cast the function pointer to the appropriate type. */
- vfn = value_cast (lookup_pointer_type (TYPE_FN_FIELD_TYPE (f, j)),
- 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 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 vfn;
+ return gnuv3_get_virtual_fn (gdbarch, *value_p, TYPE_FN_FIELD_TYPE (f, j),
+ TYPE_FN_FIELD_VOFFSET (f, j));
}
/* Compute the offset of the baseclass which is
The result is the offset of the baseclass value relative
to (the address of)(ARG) + OFFSET.
- -1 is returned on error. */
+ -1 is returned on error. */
+
static int
-gnuv3_baseclass_offset (struct type *type, int index, const bfd_byte *valaddr,
- CORE_ADDR address)
+gnuv3_baseclass_offset (struct type *type, int index,
+ const bfd_byte *valaddr, int embedded_offset,
+ CORE_ADDR address, const struct value *val)
{
- struct type *vtable_type = gdbarch_data (current_gdbarch,
- vtable_type_gdbarch_data);
+ struct gdbarch *gdbarch;
+ struct type *ptr_type;
struct value *vtable;
- struct type *vbasetype;
- struct value *offset_val, *vbase_array;
- CORE_ADDR vtable_address;
+ struct value *vbase_array;
long int cur_base_offset, base_offset;
+ /* Determine architecture. */
+ gdbarch = get_type_arch (type);
+ ptr_type = builtin_type (gdbarch)->builtin_data_ptr;
+
/* If it isn't a virtual base, this is easy. The offset is in the
type definition. */
if (!BASETYPE_VIA_VIRTUAL (type, index))
complete inheritance graph based on the debug info. Neither is
worthwhile. */
cur_base_offset = TYPE_BASECLASS_BITPOS (type, index) / 8;
- if (cur_base_offset >= - vtable_address_point_offset ())
+ if (cur_base_offset >= - vtable_address_point_offset (gdbarch))
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)
+ cur_base_offset = cur_base_offset + vtable_address_point_offset (gdbarch);
+ if ((- cur_base_offset) % TYPE_LENGTH (ptr_type) != 0)
error (_("Misaligned vbase offset."));
- cur_base_offset = cur_base_offset
- / ((int) TYPE_LENGTH (builtin_type_void_data_ptr));
-
- /* We're now looking for the cur_base_offset'th entry (negative index)
- in the vcall_and_vbase_offsets array. We used to cast the object to
- its TYPE_VPTR_BASETYPE, and reference the vtable as TYPE_VPTR_FIELDNO;
- however, that cast can not be done without calling baseclass_offset again
- if the TYPE_VPTR_BASETYPE is a virtual base class, as described in the
- v3 C++ ABI Section 2.4.I.2.b. Fortunately the ABI guarantees that the
- vtable pointer will be located at the beginning of the object, so we can
- bypass the casting. Verify that the TYPE_VPTR_FIELDNO is in fact at the
- start of whichever baseclass it resides in, as a sanity measure - iff
- we have debugging information for that baseclass. */
-
- vbasetype = TYPE_VPTR_BASETYPE (type);
- if (TYPE_VPTR_FIELDNO (vbasetype) < 0)
- fill_in_vptr_fieldno (vbasetype);
-
- if (TYPE_VPTR_FIELDNO (vbasetype) >= 0
- && TYPE_FIELD_BITPOS (vbasetype, TYPE_VPTR_FIELDNO (vbasetype)) != 0)
- 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,
- address));
- vtable = value_at_lazy (vtable_type,
- vtable_address - vtable_address_point_offset ());
- offset_val = value_from_longest(builtin_type_int, cur_base_offset);
+ cur_base_offset = cur_base_offset / ((int) TYPE_LENGTH (ptr_type));
+
+ vtable = gnuv3_get_vtable (gdbarch, type, address + embedded_offset);
+ gdb_assert (vtable != NULL);
vbase_array = value_field (vtable, vtable_field_vcall_and_vbase_offsets);
- base_offset = value_as_long (value_subscript (vbase_array, offset_val));
+ base_offset = value_as_long (value_subscript (vbase_array, cur_base_offset));
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. */
+
+static const char *
+gnuv3_find_method_in (struct type *domain, CORE_ADDR voffset,
+ LONGEST adjustment)
+{
+ int i;
+
+ /* Search this class first. */
+ 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;
+}
+
+/* Decode GNU v3 method pointer. */
+
+static int
+gnuv3_decode_method_ptr (struct gdbarch *gdbarch,
+ const gdb_byte *contents,
+ CORE_ADDR *value_p,
+ LONGEST *adjustment_p)
+{
+ struct type *funcptr_type = builtin_type (gdbarch)->builtin_func_ptr;
+ struct type *offset_type = vtable_ptrdiff_type (gdbarch);
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+ CORE_ADDR ptr_value;
+ LONGEST voffset, adjustment;
+ int vbit;
+
+ /* Extract the pointer to member. The first element is either a pointer
+ or a vtable offset. For pointers, we need to use extract_typed_address
+ to allow the back-end to convert the pointer to a GDB address -- but
+ vtable offsets we must handle as integers. At this point, we do not
+ yet know which case we have, so we extract the value under both
+ interpretations and choose the right one later on. */
+ ptr_value = extract_typed_address (contents, funcptr_type);
+ voffset = extract_signed_integer (contents,
+ TYPE_LENGTH (funcptr_type), byte_order);
+ contents += TYPE_LENGTH (funcptr_type);
+ adjustment = extract_signed_integer (contents,
+ TYPE_LENGTH (offset_type), byte_order);
+
+ if (!gdbarch_vbit_in_delta (gdbarch))
+ {
+ vbit = voffset & 1;
+ voffset = voffset ^ vbit;
+ }
+ else
+ {
+ vbit = adjustment & 1;
+ adjustment = adjustment >> 1;
+ }
+
+ *value_p = vbit? voffset : ptr_value;
+ *adjustment_p = adjustment;
+ return vbit;
+}
+
+/* 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)
+{
+ struct type *domain = TYPE_DOMAIN_TYPE (type);
+ struct gdbarch *gdbarch = get_type_arch (domain);
+ CORE_ADDR ptr_value;
+ LONGEST adjustment;
+ int vbit;
+
+ /* Extract the pointer to member. */
+ vbit = gnuv3_decode_method_ptr (gdbarch, contents, &ptr_value, &adjustment);
+
+ /* 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 (vtable_ptrdiff_type (gdbarch));
+
+ 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);
+
+ fprintf_filtered (stream, "&virtual ");
+ if (demangled_name == NULL)
+ fputs_filtered (physname, stream);
+ else
+ {
+ fputs_filtered (demangled_name, stream);
+ xfree (demangled_name);
+ }
+ return;
+ }
+ }
+ else if (ptr_value != 0)
+ {
+ /* Found a non-virtual function: print out the type. */
+ fputs_filtered ("(", stream);
+ c_print_type (type, "", stream, -1, 0);
+ fputs_filtered (") ", stream);
+ }
+
+ /* 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 (gdbarch, 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 (struct type *type)
+{
+ struct gdbarch *gdbarch = get_type_arch (type);
+
+ return 2 * TYPE_LENGTH (builtin_type (gdbarch)->builtin_data_ptr);
+}
+
+/* GNU v3 implementation of cplus_make_method_ptr. */
+
+static void
+gnuv3_make_method_ptr (struct type *type, gdb_byte *contents,
+ CORE_ADDR value, int is_virtual)
+{
+ struct gdbarch *gdbarch = get_type_arch (type);
+ int size = TYPE_LENGTH (builtin_type (gdbarch)->builtin_data_ptr);
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+
+ /* 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 (gdbarch))
+ {
+ store_unsigned_integer (contents, size, byte_order, value | is_virtual);
+ store_unsigned_integer (contents + size, size, byte_order, 0);
+ }
+ else
+ {
+ store_unsigned_integer (contents, size, byte_order, value);
+ store_unsigned_integer (contents + size, size, byte_order, 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)
+{
+ struct gdbarch *gdbarch;
+ const gdb_byte *contents = value_contents (method_ptr);
+ CORE_ADDR ptr_value;
+ struct type *domain_type, *final_type, *method_type;
+ LONGEST adjustment;
+ int vbit;
+
+ domain_type = TYPE_DOMAIN_TYPE (check_typedef (value_type (method_ptr)));
+ final_type = lookup_pointer_type (domain_type);
+
+ method_type = TYPE_TARGET_TYPE (check_typedef (value_type (method_ptr)));
+
+ /* Extract the pointer to member. */
+ gdbarch = get_type_arch (domain_type);
+ vbit = gnuv3_decode_method_ptr (gdbarch, contents, &ptr_value, &adjustment);
+
+ /* 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 (gdbarch)->builtin_data_ptr, *this_p);
+ *this_p = value_ptradd (*this_p, adjustment);
+ *this_p = value_cast (final_type, *this_p);
+
+ if (vbit)
+ {
+ LONGEST voffset;
+
+ voffset = ptr_value / TYPE_LENGTH (vtable_ptrdiff_type (gdbarch));
+ return gnuv3_get_virtual_fn (gdbarch, 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 gdbarch *gdbarch = get_frame_arch (frame);
+ struct minimal_symbol *thunk_sym, *fn_sym;
+ struct obj_section *section;
+ char *thunk_name, *fn_name;
+
+ real_stop_pc = gdbarch_skip_trampoline_code (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
+ (gdbarch, frame, method_stop_pc);
+ if (real_stop_pc == 0)
+ real_stop_pc = method_stop_pc;
+
+ return real_stop_pc;
+}
+
+/* Return nonzero if a type should be passed by reference.
+
+ The rule in the v3 ABI document comes from section 3.1.1. If the
+ type has a non-trivial copy constructor or destructor, then the
+ caller must make a copy (by calling the copy constructor if there
+ is one or perform the copy itself otherwise), pass the address of
+ the copy, and then destroy the temporary (if necessary).
+
+ For return values with non-trivial copy constructors or
+ destructors, space will be allocated in the caller, and a pointer
+ will be passed as the first argument (preceding "this").
+
+ We don't have a bulletproof mechanism for determining whether a
+ constructor or destructor is trivial. For GCC and DWARF2 debug
+ information, we can check the artificial flag.
+
+ We don't do anything with the constructors or destructors,
+ but we have to get the argument passing right anyway. */
+static int
+gnuv3_pass_by_reference (struct type *type)
+{
+ int fieldnum, fieldelem;
+
+ CHECK_TYPEDEF (type);
+
+ /* We're only interested in things that can have methods. */
+ if (TYPE_CODE (type) != TYPE_CODE_STRUCT
+ && TYPE_CODE (type) != TYPE_CODE_CLASS
+ && TYPE_CODE (type) != TYPE_CODE_UNION)
+ return 0;
+
+ for (fieldnum = 0; fieldnum < TYPE_NFN_FIELDS (type); fieldnum++)
+ for (fieldelem = 0; fieldelem < TYPE_FN_FIELDLIST_LENGTH (type, fieldnum);
+ fieldelem++)
+ {
+ struct fn_field *fn = TYPE_FN_FIELDLIST1 (type, fieldnum);
+ char *name = TYPE_FN_FIELDLIST_NAME (type, fieldnum);
+ struct type *fieldtype = TYPE_FN_FIELD_TYPE (fn, fieldelem);
+
+ /* If this function is marked as artificial, it is compiler-generated,
+ and we assume it is trivial. */
+ if (TYPE_FN_FIELD_ARTIFICIAL (fn, fieldelem))
+ continue;
+
+ /* If we've found a destructor, we must pass this by reference. */
+ if (name[0] == '~')
+ return 1;
+
+ /* If the mangled name of this method doesn't indicate that it
+ is a constructor, we're not interested.
+
+ FIXME drow/2007-09-23: We could do this using the name of
+ the method and the name of the class instead of dealing
+ with the mangled name. We don't have a convenient function
+ to strip off both leading scope qualifiers and trailing
+ template arguments yet. */
+ if (!is_constructor_name (TYPE_FN_FIELD_PHYSNAME (fn, fieldelem)))
+ continue;
+
+ /* If this method takes two arguments, and the second argument is
+ a reference to this class, then it is a copy constructor. */
+ if (TYPE_NFIELDS (fieldtype) == 2
+ && TYPE_CODE (TYPE_FIELD_TYPE (fieldtype, 1)) == TYPE_CODE_REF
+ && check_typedef (TYPE_TARGET_TYPE (TYPE_FIELD_TYPE (fieldtype,
+ 1))) == type)
+ return 1;
+ }
+
+ /* Even if all the constructors and destructors were artificial, one
+ of them may have invoked a non-artificial constructor or
+ destructor in a base class. If any base class needs to be passed
+ by reference, so does this class. Similarly for members, which
+ are constructed whenever this class is. We do not need to worry
+ about recursive loops here, since we are only looking at members
+ of complete class type. Also ignore any static members. */
+ for (fieldnum = 0; fieldnum < TYPE_NFIELDS (type); fieldnum++)
+ if (! field_is_static (&TYPE_FIELD (type, fieldnum))
+ && gnuv3_pass_by_reference (TYPE_FIELD_TYPE (type, fieldnum)))
+ return 1;
+
+ return 0;
+}
+
static void
init_gnuv3_ops (void)
{
- vtable_type_gdbarch_data = gdbarch_data_register_post_init (build_gdb_vtable_type);
+ vtable_type_gdbarch_data
+ = gdbarch_data_register_post_init (build_gdb_vtable_type);
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;
+ gnu_v3_abi_ops.pass_by_reference = gnuv3_pass_by_reference;
}
extern initialize_file_ftype _initialize_gnu_v3_abi; /* -Wmissing-prototypes */
projects / deliverable / binutils-gdb.git / blobdiff