blob: 97d889b2bcf14e5504e2d75d783faef9712f4714 [file] [log] [blame]
/* Perform non-arithmetic operations on values, for GDB.
Copyright (C) 1986-2012 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 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
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
#include "symtab.h"
#include "gdbtypes.h"
#include "value.h"
#include "frame.h"
#include "inferior.h"
#include "gdbcore.h"
#include "target.h"
#include "demangle.h"
#include "language.h"
#include "gdbcmd.h"
#include "regcache.h"
#include "cp-abi.h"
#include "block.h"
#include "infcall.h"
#include "dictionary.h"
#include "cp-support.h"
#include "dfp.h"
#include "user-regs.h"
#include "tracepoint.h"
#include <errno.h>
#include "gdb_string.h"
#include "gdb_assert.h"
#include "cp-support.h"
#include "observer.h"
#include "objfiles.h"
#include "symtab.h"
#include "exceptions.h"
extern int overload_debug;
/* Local functions. */
static int typecmp (int staticp, int varargs, int nargs,
struct field t1[], struct value *t2[]);
static struct value *search_struct_field (const char *, struct value *,
int, struct type *, int);
static struct value *search_struct_method (const char *, struct value **,
struct value **,
int, int *, struct type *);
static int find_oload_champ_namespace (struct value **, int,
const char *, const char *,
struct symbol ***,
struct badness_vector **,
const int no_adl);
static
int find_oload_champ_namespace_loop (struct value **, int,
const char *, const char *,
int, struct symbol ***,
struct badness_vector **, int *,
const int no_adl);
static int find_oload_champ (struct value **, int, int, int,
struct fn_field *, struct symbol **,
struct badness_vector **);
static int oload_method_static (int, struct fn_field *, int);
enum oload_classification { STANDARD, NON_STANDARD, INCOMPATIBLE };
static enum
oload_classification classify_oload_match (struct badness_vector *,
int, int);
static struct value *value_struct_elt_for_reference (struct type *,
int, struct type *,
char *,
struct type *,
int, enum noside);
static struct value *value_namespace_elt (const struct type *,
char *, int , enum noside);
static struct value *value_maybe_namespace_elt (const struct type *,
char *, int,
enum noside);
static CORE_ADDR allocate_space_in_inferior (int);
static struct value *cast_into_complex (struct type *, struct value *);
static struct fn_field *find_method_list (struct value **, const char *,
int, struct type *, int *,
struct type **, int *);
void _initialize_valops (void);
#if 0
/* Flag for whether we want to abandon failed expression evals by
default. */
static int auto_abandon = 0;
#endif
int overload_resolution = 0;
static void
show_overload_resolution (struct ui_file *file, int from_tty,
struct cmd_list_element *c,
const char *value)
{
fprintf_filtered (file, _("Overload resolution in evaluating "
"C++ functions is %s.\n"),
value);
}
/* Find the address of function name NAME in the inferior. If OBJF_P
is non-NULL, *OBJF_P will be set to the OBJFILE where the function
is defined. */
struct value *
find_function_in_inferior (const char *name, struct objfile **objf_p)
{
struct symbol *sym;
sym = lookup_symbol (name, 0, VAR_DOMAIN, 0);
if (sym != NULL)
{
if (SYMBOL_CLASS (sym) != LOC_BLOCK)
{
error (_("\"%s\" exists in this program but is not a function."),
name);
}
if (objf_p)
*objf_p = SYMBOL_SYMTAB (sym)->objfile;
return value_of_variable (sym, NULL);
}
else
{
struct minimal_symbol *msymbol =
lookup_minimal_symbol (name, NULL, NULL);
if (msymbol != NULL)
{
struct objfile *objfile = msymbol_objfile (msymbol);
struct gdbarch *gdbarch = get_objfile_arch (objfile);
struct type *type;
CORE_ADDR maddr;
type = lookup_pointer_type (builtin_type (gdbarch)->builtin_char);
type = lookup_function_type (type);
type = lookup_pointer_type (type);
maddr = SYMBOL_VALUE_ADDRESS (msymbol);
if (objf_p)
*objf_p = objfile;
return value_from_pointer (type, maddr);
}
else
{
if (!target_has_execution)
error (_("evaluation of this expression "
"requires the target program to be active"));
else
error (_("evaluation of this expression requires the "
"program to have a function \"%s\"."),
name);
}
}
}
/* Allocate NBYTES of space in the inferior using the inferior's
malloc and return a value that is a pointer to the allocated
space. */
struct value *
value_allocate_space_in_inferior (int len)
{
struct objfile *objf;
struct value *val = find_function_in_inferior ("malloc", &objf);
struct gdbarch *gdbarch = get_objfile_arch (objf);
struct value *blocklen;
blocklen = value_from_longest (builtin_type (gdbarch)->builtin_int, len);
val = call_function_by_hand (val, 1, &blocklen);
if (value_logical_not (val))
{
if (!target_has_execution)
error (_("No memory available to program now: "
"you need to start the target first"));
else
error (_("No memory available to program: call to malloc failed"));
}
return val;
}
static CORE_ADDR
allocate_space_in_inferior (int len)
{
return value_as_long (value_allocate_space_in_inferior (len));
}
/* Cast struct value VAL to type TYPE and return as a value.
Both type and val must be of TYPE_CODE_STRUCT or TYPE_CODE_UNION
for this to work. Typedef to one of the codes is permitted.
Returns NULL if the cast is neither an upcast nor a downcast. */
static struct value *
value_cast_structs (struct type *type, struct value *v2)
{
struct type *t1;
struct type *t2;
struct value *v;
gdb_assert (type != NULL && v2 != NULL);
t1 = check_typedef (type);
t2 = check_typedef (value_type (v2));
/* Check preconditions. */
gdb_assert ((TYPE_CODE (t1) == TYPE_CODE_STRUCT
|| TYPE_CODE (t1) == TYPE_CODE_UNION)
&& !!"Precondition is that type is of STRUCT or UNION kind.");
gdb_assert ((TYPE_CODE (t2) == TYPE_CODE_STRUCT
|| TYPE_CODE (t2) == TYPE_CODE_UNION)
&& !!"Precondition is that value is of STRUCT or UNION kind");
if (TYPE_NAME (t1) != NULL
&& TYPE_NAME (t2) != NULL
&& !strcmp (TYPE_NAME (t1), TYPE_NAME (t2)))
return NULL;
/* Upcasting: look in the type of the source to see if it contains the
type of the target as a superclass. If so, we'll need to
offset the pointer rather than just change its type. */
if (TYPE_NAME (t1) != NULL)
{
v = search_struct_field (type_name_no_tag (t1),
v2, 0, t2, 1);
if (v)
return v;
}
/* Downcasting: look in the type of the target to see if it contains the
type of the source as a superclass. If so, we'll need to
offset the pointer rather than just change its type. */
if (TYPE_NAME (t2) != NULL)
{
/* Try downcasting using the run-time type of the value. */
int full, top, using_enc;
struct type *real_type;
real_type = value_rtti_type (v2, &full, &top, &using_enc);
if (real_type)
{
v = value_full_object (v2, real_type, full, top, using_enc);
v = value_at_lazy (real_type, value_address (v));
/* We might be trying to cast to the outermost enclosing
type, in which case search_struct_field won't work. */
if (TYPE_NAME (real_type) != NULL
&& !strcmp (TYPE_NAME (real_type), TYPE_NAME (t1)))
return v;
v = search_struct_field (type_name_no_tag (t2), v, 0, real_type, 1);
if (v)
return v;
}
/* Try downcasting using information from the destination type
T2. This wouldn't work properly for classes with virtual
bases, but those were handled above. */
v = search_struct_field (type_name_no_tag (t2),
value_zero (t1, not_lval), 0, t1, 1);
if (v)
{
/* Downcasting is possible (t1 is superclass of v2). */
CORE_ADDR addr2 = value_address (v2);
addr2 -= value_address (v) + value_embedded_offset (v);
return value_at (type, addr2);
}
}
return NULL;
}
/* Cast one pointer or reference type to another. Both TYPE and
the type of ARG2 should be pointer types, or else both should be
reference types. If SUBCLASS_CHECK is non-zero, this will force a
check to see whether TYPE is a superclass of ARG2's type. If
SUBCLASS_CHECK is zero, then the subclass check is done only when
ARG2 is itself non-zero. Returns the new pointer or reference. */
struct value *
value_cast_pointers (struct type *type, struct value *arg2,
int subclass_check)
{
struct type *type1 = check_typedef (type);
struct type *type2 = check_typedef (value_type (arg2));
struct type *t1 = check_typedef (TYPE_TARGET_TYPE (type1));
struct type *t2 = check_typedef (TYPE_TARGET_TYPE (type2));
if (TYPE_CODE (t1) == TYPE_CODE_STRUCT
&& TYPE_CODE (t2) == TYPE_CODE_STRUCT
&& (subclass_check || !value_logical_not (arg2)))
{
struct value *v2;
if (TYPE_CODE (type2) == TYPE_CODE_REF)
v2 = coerce_ref (arg2);
else
v2 = value_ind (arg2);
gdb_assert (TYPE_CODE (check_typedef (value_type (v2)))
== TYPE_CODE_STRUCT && !!"Why did coercion fail?");
v2 = value_cast_structs (t1, v2);
/* At this point we have what we can have, un-dereference if needed. */
if (v2)
{
struct value *v = value_addr (v2);
deprecated_set_value_type (v, type);
return v;
}
}
/* No superclass found, just change the pointer type. */
arg2 = value_copy (arg2);
deprecated_set_value_type (arg2, type);
set_value_enclosing_type (arg2, type);
set_value_pointed_to_offset (arg2, 0); /* pai: chk_val */
return arg2;
}
/* Cast value ARG2 to type TYPE and return as a value.
More general than a C cast: accepts any two types of the same length,
and if ARG2 is an lvalue it can be cast into anything at all. */
/* In C++, casts may change pointer or object representations. */
struct value *
value_cast (struct type *type, struct value *arg2)
{
enum type_code code1;
enum type_code code2;
int scalar;
struct type *type2;
int convert_to_boolean = 0;
if (value_type (arg2) == type)
return arg2;
code1 = TYPE_CODE (check_typedef (type));
/* Check if we are casting struct reference to struct reference. */
if (code1 == TYPE_CODE_REF)
{
/* We dereference type; then we recurse and finally
we generate value of the given reference. Nothing wrong with
that. */
struct type *t1 = check_typedef (type);
struct type *dereftype = check_typedef (TYPE_TARGET_TYPE (t1));
struct value *val = value_cast (dereftype, arg2);
return value_ref (val);
}
code2 = TYPE_CODE (check_typedef (value_type (arg2)));
if (code2 == TYPE_CODE_REF)
/* We deref the value and then do the cast. */
return value_cast (type, coerce_ref (arg2));
CHECK_TYPEDEF (type);
code1 = TYPE_CODE (type);
arg2 = coerce_ref (arg2);
type2 = check_typedef (value_type (arg2));
/* You can't cast to a reference type. See value_cast_pointers
instead. */
gdb_assert (code1 != TYPE_CODE_REF);
/* A cast to an undetermined-length array_type, such as
(TYPE [])OBJECT, is treated like a cast to (TYPE [N])OBJECT,
where N is sizeof(OBJECT)/sizeof(TYPE). */
if (code1 == TYPE_CODE_ARRAY)
{
struct type *element_type = TYPE_TARGET_TYPE (type);
unsigned element_length = TYPE_LENGTH (check_typedef (element_type));
if (element_length > 0 && TYPE_ARRAY_UPPER_BOUND_IS_UNDEFINED (type))
{
struct type *range_type = TYPE_INDEX_TYPE (type);
int val_length = TYPE_LENGTH (type2);
LONGEST low_bound, high_bound, new_length;
if (get_discrete_bounds (range_type, &low_bound, &high_bound) < 0)
low_bound = 0, high_bound = 0;
new_length = val_length / element_length;
if (val_length % element_length != 0)
warning (_("array element type size does not "
"divide object size in cast"));
/* FIXME-type-allocation: need a way to free this type when
we are done with it. */
range_type = create_range_type ((struct type *) NULL,
TYPE_TARGET_TYPE (range_type),
low_bound,
new_length + low_bound - 1);
deprecated_set_value_type (arg2,
create_array_type ((struct type *) NULL,
element_type,
range_type));
return arg2;
}
}
if (current_language->c_style_arrays
&& TYPE_CODE (type2) == TYPE_CODE_ARRAY
&& !TYPE_VECTOR (type2))
arg2 = value_coerce_array (arg2);
if (TYPE_CODE (type2) == TYPE_CODE_FUNC)
arg2 = value_coerce_function (arg2);
type2 = check_typedef (value_type (arg2));
code2 = TYPE_CODE (type2);
if (code1 == TYPE_CODE_COMPLEX)
return cast_into_complex (type, arg2);
if (code1 == TYPE_CODE_BOOL)
{
code1 = TYPE_CODE_INT;
convert_to_boolean = 1;
}
if (code1 == TYPE_CODE_CHAR)
code1 = TYPE_CODE_INT;
if (code2 == TYPE_CODE_BOOL || code2 == TYPE_CODE_CHAR)
code2 = TYPE_CODE_INT;
scalar = (code2 == TYPE_CODE_INT || code2 == TYPE_CODE_FLT
|| code2 == TYPE_CODE_DECFLOAT || code2 == TYPE_CODE_ENUM
|| code2 == TYPE_CODE_RANGE);
if ((code1 == TYPE_CODE_STRUCT || code1 == TYPE_CODE_UNION)
&& (code2 == TYPE_CODE_STRUCT || code2 == TYPE_CODE_UNION)
&& TYPE_NAME (type) != 0)
{
struct value *v = value_cast_structs (type, arg2);
if (v)
return v;
}
if (code1 == TYPE_CODE_FLT && scalar)
return value_from_double (type, value_as_double (arg2));
else if (code1 == TYPE_CODE_DECFLOAT && scalar)
{
enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
int dec_len = TYPE_LENGTH (type);
gdb_byte dec[16];
if (code2 == TYPE_CODE_FLT)
decimal_from_floating (arg2, dec, dec_len, byte_order);
else if (code2 == TYPE_CODE_DECFLOAT)
decimal_convert (value_contents (arg2), TYPE_LENGTH (type2),
byte_order, dec, dec_len, byte_order);
else
/* The only option left is an integral type. */
decimal_from_integral (arg2, dec, dec_len, byte_order);
return value_from_decfloat (type, dec);
}
else if ((code1 == TYPE_CODE_INT || code1 == TYPE_CODE_ENUM
|| code1 == TYPE_CODE_RANGE)
&& (scalar || code2 == TYPE_CODE_PTR
|| code2 == TYPE_CODE_MEMBERPTR))
{
LONGEST longest;
/* When we cast pointers to integers, we mustn't use
gdbarch_pointer_to_address to find the address the pointer
represents, as value_as_long would. GDB should evaluate
expressions just as the compiler would --- and the compiler
sees a cast as a simple reinterpretation of the pointer's
bits. */
if (code2 == TYPE_CODE_PTR)
longest = extract_unsigned_integer
(value_contents (arg2), TYPE_LENGTH (type2),
gdbarch_byte_order (get_type_arch (type2)));
else
longest = value_as_long (arg2);
return value_from_longest (type, convert_to_boolean ?
(LONGEST) (longest ? 1 : 0) : longest);
}
else if (code1 == TYPE_CODE_PTR && (code2 == TYPE_CODE_INT
|| code2 == TYPE_CODE_ENUM
|| code2 == TYPE_CODE_RANGE))
{
/* TYPE_LENGTH (type) is the length of a pointer, but we really
want the length of an address! -- we are really dealing with
addresses (i.e., gdb representations) not pointers (i.e.,
target representations) here.
This allows things like "print *(int *)0x01000234" to work
without printing a misleading message -- which would
otherwise occur when dealing with a target having two byte
pointers and four byte addresses. */
int addr_bit = gdbarch_addr_bit (get_type_arch (type2));
LONGEST longest = value_as_long (arg2);
if (addr_bit < sizeof (LONGEST) * HOST_CHAR_BIT)
{
if (longest >= ((LONGEST) 1 << addr_bit)
|| longest <= -((LONGEST) 1 << addr_bit))
warning (_("value truncated"));
}
return value_from_longest (type, longest);
}
else if (code1 == TYPE_CODE_METHODPTR && code2 == TYPE_CODE_INT
&& value_as_long (arg2) == 0)
{
struct value *result = allocate_value (type);
cplus_make_method_ptr (type, value_contents_writeable (result), 0, 0);
return result;
}
else if (code1 == TYPE_CODE_MEMBERPTR && code2 == TYPE_CODE_INT
&& value_as_long (arg2) == 0)
{
/* The Itanium C++ ABI represents NULL pointers to members as
minus one, instead of biasing the normal case. */
return value_from_longest (type, -1);
}
else if (code1 == TYPE_CODE_ARRAY && TYPE_VECTOR (type) && scalar)
{
/* Widen the scalar to a vector. */
struct type *eltype;
struct value *val;
LONGEST low_bound, high_bound;
int i;
if (!get_array_bounds (type, &low_bound, &high_bound))
error (_("Could not determine the vector bounds"));
eltype = check_typedef (TYPE_TARGET_TYPE (type));
arg2 = value_cast (eltype, arg2);
val = allocate_value (type);
for (i = 0; i < high_bound - low_bound + 1; i++)
{
/* Duplicate the contents of arg2 into the destination vector. */
memcpy (value_contents_writeable (val) + (i * TYPE_LENGTH (eltype)),
value_contents_all (arg2), TYPE_LENGTH (eltype));
}
return val;
}
else if (TYPE_LENGTH (type) == TYPE_LENGTH (type2))
{
if (code1 == TYPE_CODE_PTR && code2 == TYPE_CODE_PTR)
return value_cast_pointers (type, arg2, 0);
arg2 = value_copy (arg2);
deprecated_set_value_type (arg2, type);
set_value_enclosing_type (arg2, type);
set_value_pointed_to_offset (arg2, 0); /* pai: chk_val */
return arg2;
}
else if (VALUE_LVAL (arg2) == lval_memory)
return value_at_lazy (type, value_address (arg2));
else if (code1 == TYPE_CODE_VOID)
{
return value_zero (type, not_lval);
}
else
{
error (_("Invalid cast."));
return 0;
}
}
/* The C++ reinterpret_cast operator. */
struct value *
value_reinterpret_cast (struct type *type, struct value *arg)
{
struct value *result;
struct type *real_type = check_typedef (type);
struct type *arg_type, *dest_type;
int is_ref = 0;
enum type_code dest_code, arg_code;
/* Do reference, function, and array conversion. */
arg = coerce_array (arg);
/* Attempt to preserve the type the user asked for. */
dest_type = type;
/* If we are casting to a reference type, transform
reinterpret_cast<T&>(V) to *reinterpret_cast<T*>(&V). */
if (TYPE_CODE (real_type) == TYPE_CODE_REF)
{
is_ref = 1;
arg = value_addr (arg);
dest_type = lookup_pointer_type (TYPE_TARGET_TYPE (dest_type));
real_type = lookup_pointer_type (real_type);
}
arg_type = value_type (arg);
dest_code = TYPE_CODE (real_type);
arg_code = TYPE_CODE (arg_type);
/* We can convert pointer types, or any pointer type to int, or int
type to pointer. */
if ((dest_code == TYPE_CODE_PTR && arg_code == TYPE_CODE_INT)
|| (dest_code == TYPE_CODE_INT && arg_code == TYPE_CODE_PTR)
|| (dest_code == TYPE_CODE_METHODPTR && arg_code == TYPE_CODE_INT)
|| (dest_code == TYPE_CODE_INT && arg_code == TYPE_CODE_METHODPTR)
|| (dest_code == TYPE_CODE_MEMBERPTR && arg_code == TYPE_CODE_INT)
|| (dest_code == TYPE_CODE_INT && arg_code == TYPE_CODE_MEMBERPTR)
|| (dest_code == arg_code
&& (dest_code == TYPE_CODE_PTR
|| dest_code == TYPE_CODE_METHODPTR
|| dest_code == TYPE_CODE_MEMBERPTR)))
result = value_cast (dest_type, arg);
else
error (_("Invalid reinterpret_cast"));
if (is_ref)
result = value_cast (type, value_ref (value_ind (result)));
return result;
}
/* A helper for value_dynamic_cast. This implements the first of two
runtime checks: we iterate over all the base classes of the value's
class which are equal to the desired class; if only one of these
holds the value, then it is the answer. */
static int
dynamic_cast_check_1 (struct type *desired_type,
const gdb_byte *valaddr,
int embedded_offset,
CORE_ADDR address,
struct value *val,
struct type *search_type,
CORE_ADDR arg_addr,
struct type *arg_type,
struct value **result)
{
int i, result_count = 0;
for (i = 0; i < TYPE_N_BASECLASSES (search_type) && result_count < 2; ++i)
{
int offset = baseclass_offset (search_type, i, valaddr, embedded_offset,
address, val);
if (class_types_same_p (desired_type, TYPE_BASECLASS (search_type, i)))
{
if (address + embedded_offset + offset >= arg_addr
&& address + embedded_offset + offset < arg_addr + TYPE_LENGTH (arg_type))
{
++result_count;
if (!*result)
*result = value_at_lazy (TYPE_BASECLASS (search_type, i),
address + embedded_offset + offset);
}
}
else
result_count += dynamic_cast_check_1 (desired_type,
valaddr,
embedded_offset + offset,
address, val,
TYPE_BASECLASS (search_type, i),
arg_addr,
arg_type,
result);
}
return result_count;
}
/* A helper for value_dynamic_cast. This implements the second of two
runtime checks: we look for a unique public sibling class of the
argument's declared class. */
static int
dynamic_cast_check_2 (struct type *desired_type,
const gdb_byte *valaddr,
int embedded_offset,
CORE_ADDR address,
struct value *val,
struct type *search_type,
struct value **result)
{
int i, result_count = 0;
for (i = 0; i < TYPE_N_BASECLASSES (search_type) && result_count < 2; ++i)
{
int offset;
if (! BASETYPE_VIA_PUBLIC (search_type, i))
continue;
offset = baseclass_offset (search_type, i, valaddr, embedded_offset,
address, val);
if (class_types_same_p (desired_type, TYPE_BASECLASS (search_type, i)))
{
++result_count;
if (*result == NULL)
*result = value_at_lazy (TYPE_BASECLASS (search_type, i),
address + embedded_offset + offset);
}
else
result_count += dynamic_cast_check_2 (desired_type,
valaddr,
embedded_offset + offset,
address, val,
TYPE_BASECLASS (search_type, i),
result);
}
return result_count;
}
/* The C++ dynamic_cast operator. */
struct value *
value_dynamic_cast (struct type *type, struct value *arg)
{
int full, top, using_enc;
struct type *resolved_type = check_typedef (type);
struct type *arg_type = check_typedef (value_type (arg));
struct type *class_type, *rtti_type;
struct value *result, *tem, *original_arg = arg;
CORE_ADDR addr;
int is_ref = TYPE_CODE (resolved_type) == TYPE_CODE_REF;
if (TYPE_CODE (resolved_type) != TYPE_CODE_PTR
&& TYPE_CODE (resolved_type) != TYPE_CODE_REF)
error (_("Argument to dynamic_cast must be a pointer or reference type"));
if (TYPE_CODE (TYPE_TARGET_TYPE (resolved_type)) != TYPE_CODE_VOID
&& TYPE_CODE (TYPE_TARGET_TYPE (resolved_type)) != TYPE_CODE_CLASS)
error (_("Argument to dynamic_cast must be pointer to class or `void *'"));
class_type = check_typedef (TYPE_TARGET_TYPE (resolved_type));
if (TYPE_CODE (resolved_type) == TYPE_CODE_PTR)
{
if (TYPE_CODE (arg_type) != TYPE_CODE_PTR
&& ! (TYPE_CODE (arg_type) == TYPE_CODE_INT
&& value_as_long (arg) == 0))
error (_("Argument to dynamic_cast does not have pointer type"));
if (TYPE_CODE (arg_type) == TYPE_CODE_PTR)
{
arg_type = check_typedef (TYPE_TARGET_TYPE (arg_type));
if (TYPE_CODE (arg_type) != TYPE_CODE_CLASS)
error (_("Argument to dynamic_cast does "
"not have pointer to class type"));
}
/* Handle NULL pointers. */
if (value_as_long (arg) == 0)
return value_zero (type, not_lval);
arg = value_ind (arg);
}
else
{
if (TYPE_CODE (arg_type) != TYPE_CODE_CLASS)
error (_("Argument to dynamic_cast does not have class type"));
}
/* If the classes are the same, just return the argument. */
if (class_types_same_p (class_type, arg_type))
return value_cast (type, arg);
/* If the target type is a unique base class of the argument's
declared type, just cast it. */
if (is_ancestor (class_type, arg_type))
{
if (is_unique_ancestor (class_type, arg))
return value_cast (type, original_arg);
error (_("Ambiguous dynamic_cast"));
}
rtti_type = value_rtti_type (arg, &full, &top, &using_enc);
if (! rtti_type)
error (_("Couldn't determine value's most derived type for dynamic_cast"));
/* Compute the most derived object's address. */
addr = value_address (arg);
if (full)
{
/* Done. */
}
else if (using_enc)
addr += top;
else
addr += top + value_embedded_offset (arg);
/* dynamic_cast<void *> means to return a pointer to the
most-derived object. */
if (TYPE_CODE (resolved_type) == TYPE_CODE_PTR
&& TYPE_CODE (TYPE_TARGET_TYPE (resolved_type)) == TYPE_CODE_VOID)
return value_at_lazy (type, addr);
tem = value_at (type, addr);
/* The first dynamic check specified in 5.2.7. */
if (is_public_ancestor (arg_type, TYPE_TARGET_TYPE (resolved_type)))
{
if (class_types_same_p (rtti_type, TYPE_TARGET_TYPE (resolved_type)))
return tem;
result = NULL;
if (dynamic_cast_check_1 (TYPE_TARGET_TYPE (resolved_type),
value_contents_for_printing (tem),
value_embedded_offset (tem),
value_address (tem), tem,
rtti_type, addr,
arg_type,
&result) == 1)
return value_cast (type,
is_ref ? value_ref (result) : value_addr (result));
}
/* The second dynamic check specified in 5.2.7. */
result = NULL;
if (is_public_ancestor (arg_type, rtti_type)
&& dynamic_cast_check_2 (TYPE_TARGET_TYPE (resolved_type),
value_contents_for_printing (tem),
value_embedded_offset (tem),
value_address (tem), tem,
rtti_type, &result) == 1)
return value_cast (type,
is_ref ? value_ref (result) : value_addr (result));
if (TYPE_CODE (resolved_type) == TYPE_CODE_PTR)
return value_zero (type, not_lval);
error (_("dynamic_cast failed"));
}
/* Create a value of type TYPE that is zero, and return it. */
struct value *
value_zero (struct type *type, enum lval_type lv)
{
struct value *val = allocate_value (type);
VALUE_LVAL (val) = (lv == lval_computed ? not_lval : lv);
return val;
}
/* Create a not_lval value of numeric type TYPE that is one, and return it. */
struct value *
value_one (struct type *type)
{
struct type *type1 = check_typedef (type);
struct value *val;
if (TYPE_CODE (type1) == TYPE_CODE_DECFLOAT)
{
enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
gdb_byte v[16];
decimal_from_string (v, TYPE_LENGTH (type), byte_order, "1");
val = value_from_decfloat (type, v);
}
else if (TYPE_CODE (type1) == TYPE_CODE_FLT)
{
val = value_from_double (type, (DOUBLEST) 1);
}
else if (is_integral_type (type1))
{
val = value_from_longest (type, (LONGEST) 1);
}
else if (TYPE_CODE (type1) == TYPE_CODE_ARRAY && TYPE_VECTOR (type1))
{
struct type *eltype = check_typedef (TYPE_TARGET_TYPE (type1));
int i;
LONGEST low_bound, high_bound;
struct value *tmp;
if (!get_array_bounds (type1, &low_bound, &high_bound))
error (_("Could not determine the vector bounds"));
val = allocate_value (type);
for (i = 0; i < high_bound - low_bound + 1; i++)
{
tmp = value_one (eltype);
memcpy (value_contents_writeable (val) + i * TYPE_LENGTH (eltype),
value_contents_all (tmp), TYPE_LENGTH (eltype));
}
}
else
{
error (_("Not a numeric type."));
}
/* value_one result is never used for assignments to. */
gdb_assert (VALUE_LVAL (val) == not_lval);
return val;
}
/* Helper function for value_at, value_at_lazy, and value_at_lazy_stack. */
static struct value *
get_value_at (struct type *type, CORE_ADDR addr, int lazy)
{
struct value *val;
if (TYPE_CODE (check_typedef (type)) == TYPE_CODE_VOID)
error (_("Attempt to dereference a generic pointer."));
val = value_from_contents_and_address (type, NULL, addr);
if (!lazy)
value_fetch_lazy (val);
return val;
}
/* Return a value with type TYPE located at ADDR.
Call value_at only if the data needs to be fetched immediately;
if we can be 'lazy' and defer the fetch, perhaps indefinately, call
value_at_lazy instead. value_at_lazy simply records the address of
the data and sets the lazy-evaluation-required flag. The lazy flag
is tested in the value_contents macro, which is used if and when
the contents are actually required.
Note: value_at does *NOT* handle embedded offsets; perform such
adjustments before or after calling it. */
struct value *
value_at (struct type *type, CORE_ADDR addr)
{
return get_value_at (type, addr, 0);
}
/* Return a lazy value with type TYPE located at ADDR (cf. value_at). */
struct value *
value_at_lazy (struct type *type, CORE_ADDR addr)
{
return get_value_at (type, addr, 1);
}
/* Called only from the value_contents and value_contents_all()
macros, if the current data for a variable needs to be loaded into
value_contents(VAL). Fetches the data from the user's process, and
clears the lazy flag to indicate that the data in the buffer is
valid.
If the value is zero-length, we avoid calling read_memory, which
would abort. We mark the value as fetched anyway -- all 0 bytes of
it.
This function returns a value because it is used in the
value_contents macro as part of an expression, where a void would
not work. The value is ignored. */
int
value_fetch_lazy (struct value *val)
{
gdb_assert (value_lazy (val));
allocate_value_contents (val);
if (value_bitsize (val))
{
/* To read a lazy bitfield, read the entire enclosing value. This
prevents reading the same block of (possibly volatile) memory once
per bitfield. It would be even better to read only the containing
word, but we have no way to record that just specific bits of a
value have been fetched. */
struct type *type = check_typedef (value_type (val));
enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
struct value *parent = value_parent (val);
LONGEST offset = value_offset (val);
LONGEST num;
int length = TYPE_LENGTH (type);
if (!value_bits_valid (val,
TARGET_CHAR_BIT * offset + value_bitpos (val),
value_bitsize (val)))
error (_("value has been optimized out"));
if (!unpack_value_bits_as_long (value_type (val),
value_contents_for_printing (parent),
offset,
value_bitpos (val),
value_bitsize (val), parent, &num))
mark_value_bytes_unavailable (val,
value_embedded_offset (val),
length);
else
store_signed_integer (value_contents_raw (val), length,
byte_order, num);
}
else if (VALUE_LVAL (val) == lval_memory)
{
CORE_ADDR addr = value_address (val);
int length = TYPE_LENGTH (check_typedef (value_enclosing_type (val)));
if (length)
read_value_memory (val, 0, value_stack (val),
addr, value_contents_all_raw (val), length);
}
else if (VALUE_LVAL (val) == lval_register)
{
struct frame_info *frame;
int regnum;
struct type *type = check_typedef (value_type (val));
struct value *new_val = val, *mark = value_mark ();
/* Offsets are not supported here; lazy register values must
refer to the entire register. */
gdb_assert (value_offset (val) == 0);
while (VALUE_LVAL (new_val) == lval_register && value_lazy (new_val))
{
frame = frame_find_by_id (VALUE_FRAME_ID (new_val));
regnum = VALUE_REGNUM (new_val);
gdb_assert (frame != NULL);
/* Convertible register routines are used for multi-register
values and for interpretation in different types
(e.g. float or int from a double register). Lazy
register values should have the register's natural type,
so they do not apply. */
gdb_assert (!gdbarch_convert_register_p (get_frame_arch (frame),
regnum, type));
new_val = get_frame_register_value (frame, regnum);
}
/* If it's still lazy (for instance, a saved register on the
stack), fetch it. */
if (value_lazy (new_val))
value_fetch_lazy (new_val);
/* If the register was not saved, mark it optimized out. */
if (value_optimized_out (new_val))
set_value_optimized_out (val, 1);
else
{
set_value_lazy (val, 0);
value_contents_copy (val, value_embedded_offset (val),
new_val, value_embedded_offset (new_val),
TYPE_LENGTH (type));
}
if (frame_debug)
{
struct gdbarch *gdbarch;
frame = frame_find_by_id (VALUE_FRAME_ID (val));
regnum = VALUE_REGNUM (val);
gdbarch = get_frame_arch (frame);
fprintf_unfiltered (gdb_stdlog,
"{ value_fetch_lazy "
"(frame=%d,regnum=%d(%s),...) ",
frame_relative_level (frame), regnum,
user_reg_map_regnum_to_name (gdbarch, regnum));
fprintf_unfiltered (gdb_stdlog, "->");
if (value_optimized_out (new_val))
fprintf_unfiltered (gdb_stdlog, " optimized out");
else
{
int i;
const gdb_byte *buf = value_contents (new_val);
if (VALUE_LVAL (new_val) == lval_register)
fprintf_unfiltered (gdb_stdlog, " register=%d",
VALUE_REGNUM (new_val));
else if (VALUE_LVAL (new_val) == lval_memory)
fprintf_unfiltered (gdb_stdlog, " address=%s",
paddress (gdbarch,
value_address (new_val)));
else
fprintf_unfiltered (gdb_stdlog, " computed");
fprintf_unfiltered (gdb_stdlog, " bytes=");
fprintf_unfiltered (gdb_stdlog, "[");
for (i = 0; i < register_size (gdbarch, regnum); i++)
fprintf_unfiltered (gdb_stdlog, "%02x", buf[i]);
fprintf_unfiltered (gdb_stdlog, "]");
}
fprintf_unfiltered (gdb_stdlog, " }\n");
}
/* Dispose of the intermediate values. This prevents
watchpoints from trying to watch the saved frame pointer. */
value_free_to_mark (mark);
}
else if (VALUE_LVAL (val) == lval_computed
&& value_computed_funcs (val)->read != NULL)
value_computed_funcs (val)->read (val);
else if (value_optimized_out (val))
/* Keep it optimized out. */;
else
internal_error (__FILE__, __LINE__, _("Unexpected lazy value type."));
set_value_lazy (val, 0);
return 0;
}
void
read_value_memory (struct value *val, int embedded_offset,
int stack, CORE_ADDR memaddr,
gdb_byte *buffer, size_t length)
{
if (length)
{
VEC(mem_range_s) *available_memory;
if (get_traceframe_number () < 0
|| !traceframe_available_memory (&available_memory, memaddr, length))
{
if (stack)
read_stack (memaddr, buffer, length);
else
read_memory (memaddr, buffer, length);
}
else
{
struct target_section_table *table;
struct cleanup *old_chain;
CORE_ADDR unavail;
mem_range_s *r;
int i;
/* Fallback to reading from read-only sections. */
table = target_get_section_table (&exec_ops);
available_memory =
section_table_available_memory (available_memory,
memaddr, length,
table->sections,
table->sections_end);
old_chain = make_cleanup (VEC_cleanup(mem_range_s),
&available_memory);
normalize_mem_ranges (available_memory);
/* Mark which bytes are unavailable, and read those which
are available. */
unavail = memaddr;
for (i = 0;
VEC_iterate (mem_range_s, available_memory, i, r);
i++)
{
if (mem_ranges_overlap (r->start, r->length,
memaddr, length))
{
CORE_ADDR lo1, hi1, lo2, hi2;
CORE_ADDR start, end;
/* Get the intersection window. */
lo1 = memaddr;
hi1 = memaddr + length;
lo2 = r->start;
hi2 = r->start + r->length;
start = max (lo1, lo2);
end = min (hi1, hi2);
gdb_assert (end - memaddr <= length);
if (start > unavail)
mark_value_bytes_unavailable (val,
(embedded_offset
+ unavail - memaddr),
start - unavail);
unavail = end;
read_memory (start, buffer + start - memaddr, end - start);
}
}
if (unavail != memaddr + length)
mark_value_bytes_unavailable (val,
embedded_offset + unavail - memaddr,
(memaddr + length) - unavail);
do_cleanups (old_chain);
}
}
}
/* Store the contents of FROMVAL into the location of TOVAL.
Return a new value with the location of TOVAL and contents of FROMVAL. */
struct value *
value_assign (struct value *toval, struct value *fromval)
{
struct type *type;
struct value *val;
struct frame_id old_frame;
if (!deprecated_value_modifiable (toval))
error (_("Left operand of assignment is not a modifiable lvalue."));
toval = coerce_ref (toval);
type = value_type (toval);
if (VALUE_LVAL (toval) != lval_internalvar)
fromval = value_cast (type, fromval);
else
{
/* Coerce arrays and functions to pointers, except for arrays
which only live in GDB's storage. */
if (!value_must_coerce_to_target (fromval))
fromval = coerce_array (fromval);
}
CHECK_TYPEDEF (type);
/* Since modifying a register can trash the frame chain, and
modifying memory can trash the frame cache, we save the old frame
and then restore the new frame afterwards. */
old_frame = get_frame_id (deprecated_safe_get_selected_frame ());
switch (VALUE_LVAL (toval))
{
case lval_internalvar:
set_internalvar (VALUE_INTERNALVAR (toval), fromval);
return value_of_internalvar (get_type_arch (type),
VALUE_INTERNALVAR (toval));
case lval_internalvar_component:
set_internalvar_component (VALUE_INTERNALVAR (toval),
value_offset (toval),
value_bitpos (toval),
value_bitsize (toval),
fromval);
break;
case lval_memory:
{
const gdb_byte *dest_buffer;
CORE_ADDR changed_addr;
int changed_len;
gdb_byte buffer[sizeof (LONGEST)];
if (value_bitsize (toval))
{
struct value *parent = value_parent (toval);
changed_addr = value_address (parent) + value_offset (toval);
changed_len = (value_bitpos (toval)
+ value_bitsize (toval)
+ HOST_CHAR_BIT - 1)
/ HOST_CHAR_BIT;
/* If we can read-modify-write exactly the size of the
containing type (e.g. short or int) then do so. This
is safer for volatile bitfields mapped to hardware
registers. */
if (changed_len < TYPE_LENGTH (type)
&& TYPE_LENGTH (type) <= (int) sizeof (LONGEST)
&& ((LONGEST) changed_addr % TYPE_LENGTH (type)) == 0)
changed_len = TYPE_LENGTH (type);
if (changed_len > (int) sizeof (LONGEST))
error (_("Can't handle bitfields which "
"don't fit in a %d bit word."),
(int) sizeof (LONGEST) * HOST_CHAR_BIT);
read_memory (changed_addr, buffer, changed_len);
modify_field (type, buffer, value_as_long (fromval),
value_bitpos (toval), value_bitsize (toval));
dest_buffer = buffer;
}
else
{
changed_addr = value_address (toval);
changed_len = TYPE_LENGTH (type);
dest_buffer = value_contents (fromval);
}
write_memory_with_notification (changed_addr, dest_buffer, changed_len);
}
break;
case lval_register:
{
struct frame_info *frame;
struct gdbarch *gdbarch;
int value_reg;
/* Figure out which frame this is in currently. */
frame = frame_find_by_id (VALUE_FRAME_ID (toval));
value_reg = VALUE_REGNUM (toval);
if (!frame)
error (_("Value being assigned to is no longer active."));
gdbarch = get_frame_arch (frame);
if (gdbarch_convert_register_p (gdbarch, VALUE_REGNUM (toval), type))
{
/* If TOVAL is a special machine register requiring
conversion of program values to a special raw
format. */
gdbarch_value_to_register (gdbarch, frame,
VALUE_REGNUM (toval), type,
value_contents (fromval));
}
else
{
if (value_bitsize (toval))
{
struct value *parent = value_parent (toval);
int offset = value_offset (parent) + value_offset (toval);
int changed_len;
gdb_byte buffer[sizeof (LONGEST)];
int optim, unavail;
changed_len = (value_bitpos (toval)
+ value_bitsize (toval)
+ HOST_CHAR_BIT - 1)
/ HOST_CHAR_BIT;
if (changed_len > (int) sizeof (LONGEST))
error (_("Can't handle bitfields which "
"don't fit in a %d bit word."),
(int) sizeof (LONGEST) * HOST_CHAR_BIT);
if (!get_frame_register_bytes (frame, value_reg, offset,
changed_len, buffer,
&optim, &unavail))
{
if (optim)
error (_("value has been optimized out"));
if (unavail)
throw_error (NOT_AVAILABLE_ERROR,
_("value is not available"));
}
modify_field (type, buffer, value_as_long (fromval),
value_bitpos (toval), value_bitsize (toval));
put_frame_register_bytes (frame, value_reg, offset,
changed_len, buffer);
}
else
{
put_frame_register_bytes (frame, value_reg,
value_offset (toval),
TYPE_LENGTH (type),
value_contents (fromval));
}
}
if (deprecated_register_changed_hook)
deprecated_register_changed_hook (-1);
observer_notify_target_changed (&current_target);
break;
}
case lval_computed:
{
const struct lval_funcs *funcs = value_computed_funcs (toval);
if (funcs->write != NULL)
{
funcs->write (toval, fromval);
break;
}
}
/* Fall through. */
default:
error (_("Left operand of assignment is not an lvalue."));
}
/* Assigning to the stack pointer, frame pointer, and other
(architecture and calling convention specific) registers may
cause the frame cache to be out of date. Assigning to memory
also can. We just do this on all assignments to registers or
memory, for simplicity's sake; I doubt the slowdown matters. */
switch (VALUE_LVAL (toval))
{
case lval_memory:
case lval_register:
case lval_computed:
reinit_frame_cache ();
/* Having destroyed the frame cache, restore the selected
frame. */
/* FIXME: cagney/2002-11-02: There has to be a better way of
doing this. Instead of constantly saving/restoring the
frame. Why not create a get_selected_frame() function that,
having saved the selected frame's ID can automatically
re-find the previously selected frame automatically. */
{
struct frame_info *fi = frame_find_by_id (old_frame);
if (fi != NULL)
select_frame (fi);
}
break;
default:
break;
}
/* If the field does not entirely fill a LONGEST, then zero the sign
bits. If the field is signed, and is negative, then sign
extend. */
if ((value_bitsize (toval) > 0)
&& (value_bitsize (toval) < 8 * (int) sizeof (LONGEST)))
{
LONGEST fieldval = value_as_long (fromval);
LONGEST valmask = (((ULONGEST) 1) << value_bitsize (toval)) - 1;
fieldval &= valmask;
if (!TYPE_UNSIGNED (type)
&& (fieldval & (valmask ^ (valmask >> 1))))
fieldval |= ~valmask;
fromval = value_from_longest (type, fieldval);
}
/* The return value is a copy of TOVAL so it shares its location
information, but its contents are updated from FROMVAL. This
implies the returned value is not lazy, even if TOVAL was. */
val = value_copy (toval);
set_value_lazy (val, 0);
memcpy (value_contents_raw (val), value_contents (fromval),
TYPE_LENGTH (type));
/* We copy over the enclosing type and pointed-to offset from FROMVAL
in the case of pointer types. For object types, the enclosing type
and embedded offset must *not* be copied: the target object refered
to by TOVAL retains its original dynamic type after assignment. */
if (TYPE_CODE (type) == TYPE_CODE_PTR)
{
set_value_enclosing_type (val, value_enclosing_type (fromval));
set_value_pointed_to_offset (val, value_pointed_to_offset (fromval));
}
return val;
}
/* Extend a value VAL to COUNT repetitions of its type. */
struct value *
value_repeat (struct value *arg1, int count)
{
struct value *val;
if (VALUE_LVAL (arg1) != lval_memory)
error (_("Only values in memory can be extended with '@'."));
if (count < 1)
error (_("Invalid number %d of repetitions."), count);
val = allocate_repeat_value (value_enclosing_type (arg1), count);
VALUE_LVAL (val) = lval_memory;
set_value_address (val, value_address (arg1));
read_value_memory (val, 0, value_stack (val), value_address (val),
value_contents_all_raw (val),
TYPE_LENGTH (value_enclosing_type (val)));
return val;
}
struct value *
value_of_variable (struct symbol *var, const struct block *b)
{
struct frame_info *frame;
if (!symbol_read_needs_frame (var))
frame = NULL;
else if (!b)
frame = get_selected_frame (_("No frame selected."));
else
{
frame = block_innermost_frame (b);
if (!frame)
{
if (BLOCK_FUNCTION (b) && !block_inlined_p (b)
&& SYMBOL_PRINT_NAME (BLOCK_FUNCTION (b)))
error (_("No frame is currently executing in block %s."),
SYMBOL_PRINT_NAME (BLOCK_FUNCTION (b)));
else
error (_("No frame is currently executing in specified block"));
}
}
return read_var_value (var, frame);
}
struct value *
address_of_variable (struct symbol *var, struct block *b)
{
struct type *type = SYMBOL_TYPE (var);
struct value *val;
/* Evaluate it first; if the result is a memory address, we're fine.
Lazy evaluation pays off here. */
val = value_of_variable (var, b);
if ((VALUE_LVAL (val) == lval_memory && value_lazy (val))
|| TYPE_CODE (type) == TYPE_CODE_FUNC)
{
CORE_ADDR addr = value_address (val);
return value_from_pointer (lookup_pointer_type (type), addr);
}
/* Not a memory address; check what the problem was. */
switch (VALUE_LVAL (val))
{
case lval_register:
{
struct frame_info *frame;
const char *regname;
frame = frame_find_by_id (VALUE_FRAME_ID (val));
gdb_assert (frame);
regname = gdbarch_register_name (get_frame_arch (frame),
VALUE_REGNUM (val));
gdb_assert (regname && *regname);
error (_("Address requested for identifier "
"\"%s\" which is in register $%s"),
SYMBOL_PRINT_NAME (var), regname);
break;
}
default:
error (_("Can't take address of \"%s\" which isn't an lvalue."),
SYMBOL_PRINT_NAME (var));
break;
}
return val;
}
/* Return one if VAL does not live in target memory, but should in order
to operate on it. Otherwise return zero. */
int
value_must_coerce_to_target (struct value *val)
{
struct type *valtype;
/* The only lval kinds which do not live in target memory. */
if (VALUE_LVAL (val) != not_lval
&& VALUE_LVAL (val) != lval_internalvar)
return 0;
valtype = check_typedef (value_type (val));
switch (TYPE_CODE (valtype))
{
case TYPE_CODE_ARRAY:
return TYPE_VECTOR (valtype) ? 0 : 1;
case TYPE_CODE_STRING:
return 1;
default:
return 0;
}
}
/* Make sure that VAL lives in target memory if it's supposed to. For
instance, strings are constructed as character arrays in GDB's
storage, and this function copies them to the target. */
struct value *
value_coerce_to_target (struct value *val)
{
LONGEST length;
CORE_ADDR addr;
if (!value_must_coerce_to_target (val))
return val;
length = TYPE_LENGTH (check_typedef (value_type (val)));
addr = allocate_space_in_inferior (length);
write_memory (addr, value_contents (val), length);
return value_at_lazy (value_type (val), addr);
}
/* Given a value which is an array, return a value which is a pointer
to its first element, regardless of whether or not the array has a
nonzero lower bound.
FIXME: A previous comment here indicated that this routine should
be substracting the array's lower bound. It's not clear to me that
this is correct. Given an array subscripting operation, it would
certainly work to do the adjustment here, essentially computing:
(&array[0] - (lowerbound * sizeof array[0])) + (index * sizeof array[0])
However I believe a more appropriate and logical place to account
for the lower bound is to do so in value_subscript, essentially
computing:
(&array[0] + ((index - lowerbound) * sizeof array[0]))
As further evidence consider what would happen with operations
other than array subscripting, where the caller would get back a
value that had an address somewhere before the actual first element
of the array, and the information about the lower bound would be
lost because of the coercion to pointer type. */
struct value *
value_coerce_array (struct value *arg1)
{
struct type *type = check_typedef (value_type (arg1));
/* If the user tries to do something requiring a pointer with an
array that has not yet been pushed to the target, then this would
be a good time to do so. */
arg1 = value_coerce_to_target (arg1);
if (VALUE_LVAL (arg1) != lval_memory)
error (_("Attempt to take address of value not located in memory."));
return value_from_pointer (lookup_pointer_type (TYPE_TARGET_TYPE (type)),
value_address (arg1));
}
/* Given a value which is a function, return a value which is a pointer
to it. */
struct value *
value_coerce_function (struct value *arg1)
{
struct value *retval;
if (VALUE_LVAL (arg1) != lval_memory)
error (_("Attempt to take address of value not located in memory."));
retval = value_from_pointer (lookup_pointer_type (value_type (arg1)),
value_address (arg1));
return retval;
}
/* Return a pointer value for the object for which ARG1 is the
contents. */
struct value *
value_addr (struct value *arg1)
{
struct value *arg2;
struct type *type = check_typedef (value_type (arg1));
if (TYPE_CODE (type) == TYPE_CODE_REF)
{
/* Copy the value, but change the type from (T&) to (T*). We
keep the same location information, which is efficient, and
allows &(&X) to get the location containing the reference. */
arg2 = value_copy (arg1);
deprecated_set_value_type (arg2,
lookup_pointer_type (TYPE_TARGET_TYPE (type)));
return arg2;
}
if (TYPE_CODE (type) == TYPE_CODE_FUNC)
return value_coerce_function (arg1);
/* If this is an array that has not yet been pushed to the target,
then this would be a good time to force it to memory. */
arg1 = value_coerce_to_target (arg1);
if (VALUE_LVAL (arg1) != lval_memory)
error (_("Attempt to take address of value not located in memory."));
/* Get target memory address. */
arg2 = value_from_pointer (lookup_pointer_type (value_type (arg1)),
(value_address (arg1)
+ value_embedded_offset (arg1)));
/* This may be a pointer to a base subobject; so remember the
full derived object's type ... */
set_value_enclosing_type (arg2,
lookup_pointer_type (value_enclosing_type (arg1)));
/* ... and also the relative position of the subobject in the full
object. */
set_value_pointed_to_offset (arg2, value_embedded_offset (arg1));
return arg2;
}
/* Return a reference value for the object for which ARG1 is the
contents. */
struct value *
value_ref (struct value *arg1)
{
struct value *arg2;
struct type *type = check_typedef (value_type (arg1));
if (TYPE_CODE (type) == TYPE_CODE_REF)
return arg1;
arg2 = value_addr (arg1);
deprecated_set_value_type (arg2, lookup_reference_type (type));
return arg2;
}
/* Given a value of a pointer type, apply the C unary * operator to
it. */
struct value *
value_ind (struct value *arg1)
{
struct type *base_type;
struct value *arg2;
arg1 = coerce_array (arg1);
base_type = check_typedef (value_type (arg1));
if (VALUE_LVAL (arg1) == lval_computed)
{
const struct lval_funcs *funcs = value_computed_funcs (arg1);
if (funcs->indirect)
{
struct value *result = funcs->indirect (arg1);
if (result)
return result;
}
}
if (TYPE_CODE (base_type) == TYPE_CODE_PTR)
{
struct type *enc_type;
/* We may be pointing to something embedded in a larger object.
Get the real type of the enclosing object. */
enc_type = check_typedef (value_enclosing_type (arg1));
enc_type = TYPE_TARGET_TYPE (enc_type);
if (TYPE_CODE (check_typedef (enc_type)) == TYPE_CODE_FUNC
|| TYPE_CODE (check_typedef (enc_type)) == TYPE_CODE_METHOD)
/* For functions, go through find_function_addr, which knows
how to handle function descriptors. */
arg2 = value_at_lazy (enc_type,
find_function_addr (arg1, NULL));
else
/* Retrieve the enclosing object pointed to. */
arg2 = value_at_lazy (enc_type,
(value_as_address (arg1)
- value_pointed_to_offset (arg1)));
return readjust_indirect_value_type (arg2, enc_type, base_type, arg1);
}
error (_("Attempt to take contents of a non-pointer value."));
return 0; /* For lint -- never reached. */
}
/* Create a value for an array by allocating space in GDB, copying the
data into that space, and then setting up an array value.
The array bounds are set from LOWBOUND and HIGHBOUND, and the array
is populated from the values passed in ELEMVEC.
The element type of the array is inherited from the type of the
first element, and all elements must have the same size (though we
don't currently enforce any restriction on their types). */
struct value *
value_array (int lowbound, int highbound, struct value **elemvec)
{
int nelem;
int idx;
unsigned int typelength;
struct value *val;
struct type *arraytype;
/* Validate that the bounds are reasonable and that each of the
elements have the same size. */
nelem = highbound - lowbound + 1;
if (nelem <= 0)
{
error (_("bad array bounds (%d, %d)"), lowbound, highbound);
}
typelength = TYPE_LENGTH (value_enclosing_type (elemvec[0]));
for (idx = 1; idx < nelem; idx++)
{
if (TYPE_LENGTH (value_enclosing_type (elemvec[idx])) != typelength)
{
error (_("array elements must all be the same size"));
}
}
arraytype = lookup_array_range_type (value_enclosing_type (elemvec[0]),
lowbound, highbound);
if (!current_language->c_style_arrays)
{
val = allocate_value (arraytype);
for (idx = 0; idx < nelem; idx++)
value_contents_copy (val, idx * typelength, elemvec[idx], 0,
typelength);
return val;
}
/* Allocate space to store the array, and then initialize it by
copying in each element. */
val = allocate_value (arraytype);
for (idx = 0; idx < nelem; idx++)
value_contents_copy (val, idx * typelength, elemvec[idx], 0, typelength);
return val;
}
struct value *
value_cstring (char *ptr, int len, struct type *char_type)
{
struct value *val;
int lowbound = current_language->string_lower_bound;
int highbound = len / TYPE_LENGTH (char_type);
struct type *stringtype
= lookup_array_range_type (char_type, lowbound, highbound + lowbound - 1);
val = allocate_value (stringtype);
memcpy (value_contents_raw (val), ptr, len);
return val;
}
/* Create a value for a string constant by allocating space in the
inferior, copying the data into that space, and returning the
address with type TYPE_CODE_STRING. PTR points to the string
constant data; LEN is number of characters.
Note that string types are like array of char types with a lower
bound of zero and an upper bound of LEN - 1. Also note that the
string may contain embedded null bytes. */
struct value *
value_string (char *ptr, int len, struct type *char_type)
{
struct value *val;
int lowbound = current_language->string_lower_bound;
int highbound = len / TYPE_LENGTH (char_type);
struct type *stringtype
= lookup_string_range_type (char_type, lowbound, highbound + lowbound - 1);
val = allocate_value (stringtype);
memcpy (value_contents_raw (val), ptr, len);
return val;
}
struct value *
value_bitstring (char *ptr, int len, struct type *index_type)
{
struct value *val;
struct type *domain_type
= create_range_type (NULL, index_type, 0, len - 1);
struct type *type = create_set_type (NULL, domain_type);
TYPE_CODE (type) = TYPE_CODE_BITSTRING;
val = allocate_value (type);
memcpy (value_contents_raw (val), ptr, TYPE_LENGTH (type));
return val;
}
/* See if we can pass arguments in T2 to a function which takes
arguments of types T1. T1 is a list of NARGS arguments, and T2 is
a NULL-terminated vector. If some arguments need coercion of some
sort, then the coerced values are written into T2. Return value is
0 if the arguments could be matched, or the position at which they
differ if not.
STATICP is nonzero if the T1 argument list came from a static
member function. T2 will still include the ``this'' pointer, but
it will be skipped.
For non-static member functions, we ignore the first argument,
which is the type of the instance variable. This is because we
want to handle calls with objects from derived classes. This is
not entirely correct: we should actually check to make sure that a
requested operation is type secure, shouldn't we? FIXME. */
static int
typecmp (int staticp, int varargs, int nargs,
struct field t1[], struct value *t2[])
{
int i;
if (t2 == 0)
internal_error (__FILE__, __LINE__,
_("typecmp: no argument list"));
/* Skip ``this'' argument if applicable. T2 will always include
THIS. */
if (staticp)
t2 ++;
for (i = 0;
(i < nargs) && TYPE_CODE (t1[i].type) != TYPE_CODE_VOID;
i++)
{
struct type *tt1, *tt2;
if (!t2[i])
return i + 1;
tt1 = check_typedef (t1[i].type);
tt2 = check_typedef (value_type (t2[i]));
if (TYPE_CODE (tt1) == TYPE_CODE_REF
/* We should be doing hairy argument matching, as below. */
&& (TYPE_CODE (check_typedef (TYPE_TARGET_TYPE (tt1)))
== TYPE_CODE (tt2)))
{
if (TYPE_CODE (tt2) == TYPE_CODE_ARRAY)
t2[i] = value_coerce_array (t2[i]);
else
t2[i] = value_ref (t2[i]);
continue;
}
/* djb - 20000715 - Until the new type structure is in the
place, and we can attempt things like implicit conversions,
we need to do this so you can take something like a map<const
char *>, and properly access map["hello"], because the
argument to [] will be a reference to a pointer to a char,
and the argument will be a pointer to a char. */
while (TYPE_CODE(tt1) == TYPE_CODE_REF
|| TYPE_CODE (tt1) == TYPE_CODE_PTR)
{
tt1 = check_typedef( TYPE_TARGET_TYPE(tt1) );
}
while (TYPE_CODE(tt2) == TYPE_CODE_ARRAY
|| TYPE_CODE(tt2) == TYPE_CODE_PTR
|| TYPE_CODE(tt2) == TYPE_CODE_REF)
{
tt2 = check_typedef (TYPE_TARGET_TYPE(tt2));
}
if (TYPE_CODE (tt1) == TYPE_CODE (tt2))
continue;
/* Array to pointer is a `trivial conversion' according to the
ARM. */
/* We should be doing much hairier argument matching (see
section 13.2 of the ARM), but as a quick kludge, just check
for the same type code. */
if (TYPE_CODE (t1[i].type) != TYPE_CODE (value_type (t2[i])))
return i + 1;
}
if (varargs || t2[i] == NULL)
return 0;
return i + 1;
}
/* Helper class for do_search_struct_field that updates *RESULT_PTR
and *LAST_BOFFSET, and possibly throws an exception if the field
search has yielded ambiguous results. */
static void
update_search_result (struct value **result_ptr, struct value *v,
int *last_boffset, int boffset,
const char *name, struct type *type)
{
if (v != NULL)
{
if (*result_ptr != NULL
/* The result is not ambiguous if all the classes that are
found occupy the same space. */
&& *last_boffset != boffset)
error (_("base class '%s' is ambiguous in type '%s'"),
name, TYPE_SAFE_NAME (type));
*result_ptr = v;
*last_boffset = boffset;
}
}
/* A helper for search_struct_field. This does all the work; most
arguments are as passed to search_struct_field. The result is
stored in *RESULT_PTR, which must be initialized to NULL.
OUTERMOST_TYPE is the type of the initial type passed to
search_struct_field; this is used for error reporting when the
lookup is ambiguous. */
static void
do_search_struct_field (const char *name, struct value *arg1, int offset,
struct type *type, int looking_for_baseclass,
struct value **result_ptr,
int *last_boffset,
struct type *outermost_type)
{
int i;
int nbases;
CHECK_TYPEDEF (type);
nbases = TYPE_N_BASECLASSES (type);
if (!looking_for_baseclass)
for (i = TYPE_NFIELDS (type) - 1; i >= nbases; i--)
{
const char *t_field_name = TYPE_FIELD_NAME (type, i);
if (t_field_name && (strcmp_iw (t_field_name, name) == 0))
{
struct value *v;
if (field_is_static (&TYPE_FIELD (type, i)))
{
v = value_static_field (type, i);
if (v == 0)
error (_("field %s is nonexistent or "
"has been optimized out"),
name);
}
else
v = value_primitive_field (arg1, offset, i, type);
*result_ptr = v;
return;
}
if (t_field_name
&& (t_field_name[0] == '\0'
|| (TYPE_CODE (type) == TYPE_CODE_UNION
&& (strcmp_iw (t_field_name, "else") == 0))))
{
struct type *field_type = TYPE_FIELD_TYPE (type, i);
if (TYPE_CODE (field_type) == TYPE_CODE_UNION
|| TYPE_CODE (field_type) == TYPE_CODE_STRUCT)
{
/* Look for a match through the fields of an anonymous
union, or anonymous struct. C++ provides anonymous
unions.
In the GNU Chill (now deleted from GDB)
implementation of variant record types, each
<alternative field> has an (anonymous) union type,
each member of the union represents a <variant
alternative>. Each <variant alternative> is
represented as a struct, with a member for each
<variant field>. */
struct value *v = NULL;
int new_offset = offset;
/* This is pretty gross. In G++, the offset in an
anonymous union is relative to the beginning of the
enclosing struct. In the GNU Chill (now deleted
from GDB) implementation of variant records, the
bitpos is zero in an anonymous union field, so we
have to add the offset of the union here. */
if (TYPE_CODE (field_type) == TYPE_CODE_STRUCT
|| (TYPE_NFIELDS (field_type) > 0
&& TYPE_FIELD_BITPOS (field_type, 0) == 0))
new_offset += TYPE_FIELD_BITPOS (type, i) / 8;
do_search_struct_field (name, arg1, new_offset,
field_type,
looking_for_baseclass, &v,
last_boffset,
outermost_type);
if (v)
{
*result_ptr = v;
return;
}
}
}
}
for (i = 0; i < nbases; i++)
{
struct value *v = NULL;
struct type *basetype = check_typedef (TYPE_BASECLASS (type, i));
/* If we are looking for baseclasses, this is what we get when
we hit them. But it could happen that the base part's member
name is not yet filled in. */
int found_baseclass = (looking_for_baseclass
&& TYPE_BASECLASS_NAME (type, i) != NULL
&& (strcmp_iw (name,
TYPE_BASECLASS_NAME (type,
i)) == 0));
int boffset = value_embedded_offset (arg1) + offset;
if (BASETYPE_VIA_VIRTUAL (type, i))
{
struct value *v2;
boffset = baseclass_offset (type, i,
value_contents_for_printing (arg1),
value_embedded_offset (arg1) + offset,
value_address (arg1),
arg1);
/* The virtual base class pointer might have been clobbered
by the user program. Make sure that it still points to a
valid memory location. */
boffset += value_embedded_offset (arg1) + offset;
if (boffset < 0
|| boffset >= TYPE_LENGTH (value_enclosing_type (arg1)))
{
CORE_ADDR base_addr;
v2 = allocate_value (basetype);
base_addr = value_address (arg1) + boffset;
if (target_read_memory (base_addr,
value_contents_raw (v2),
TYPE_LENGTH (basetype)) != 0)
error (_("virtual baseclass botch"));
VALUE_LVAL (v2) = lval_memory;
set_value_address (v2, base_addr);
}
else
{
v2 = value_copy (arg1);
deprecated_set_value_type (v2, basetype);
set_value_embedded_offset (v2, boffset);
}
if (found_baseclass)
v = v2;
else
{
do_search_struct_field (name, v2, 0,
TYPE_BASECLASS (type, i),
looking_for_baseclass,
result_ptr, last_boffset,
outermost_type);
}
}
else if (found_baseclass)
v = value_primitive_field (arg1, offset, i, type);
else
{
do_search_struct_field (name, arg1,
offset + TYPE_BASECLASS_BITPOS (type,
i) / 8,
basetype, looking_for_baseclass,
result_ptr, last_boffset,
outermost_type);
}
update_search_result (result_ptr, v, last_boffset,
boffset, name, outermost_type);
}
}
/* Helper function used by value_struct_elt to recurse through
baseclasses. Look for a field NAME in ARG1. Adjust the address of
ARG1 by OFFSET bytes, and search in it assuming it has (class) type
TYPE. If found, return value, else return NULL.
If LOOKING_FOR_BASECLASS, then instead of looking for struct
fields, look for a baseclass named NAME. */
static struct value *
search_struct_field (const char *name, struct value *arg1, int offset,
struct type *type, int looking_for_baseclass)
{
struct value *result = NULL;
int boffset = 0;
do_search_struct_field (name, arg1, offset, type, looking_for_baseclass,
&result, &boffset, type);
return result;
}
/* Helper function used by value_struct_elt to recurse through
baseclasses. Look for a field NAME in ARG1. Adjust the address of
ARG1 by OFFSET bytes, and search in it assuming it has (class) type
TYPE.
If found, return value, else if name matched and args not return
(value) -1, else return NULL. */
static struct value *
search_struct_method (const char *name, struct value **arg1p,
struct value **args, int offset,
int *static_memfuncp, struct type *type)
{
int i;
struct value *v;
int name_matched = 0;
char dem_opname[64];
CHECK_TYPEDEF (type);
for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; i--)
{
const char *t_field_name = TYPE_FN_FIELDLIST_NAME (type, i);
/* FIXME! May need to check for ARM demangling here. */
if (strncmp (t_field_name, "__", 2) == 0 ||
strncmp (t_field_name, "op", 2) == 0 ||
strncmp (t_field_name, "type", 4) == 0)
{
if (cplus_demangle_opname (t_field_name, dem_opname, DMGL_ANSI))
t_field_name = dem_opname;
else if (cplus_demangle_opname (t_field_name, dem_opname, 0))
t_field_name = dem_opname;
}
if (t_field_name && (strcmp_iw (t_field_name, name) == 0))
{
int j = TYPE_FN_FIELDLIST_LENGTH (type, i) - 1;
struct fn_field *f = TYPE_FN_FIELDLIST1 (type, i);
name_matched = 1;
check_stub_method_group (type, i);
if (j > 0 && args == 0)
error (_("cannot resolve overloaded method "
"`%s': no arguments supplied"), name);
else if (j == 0 && args == 0)
{
v = value_fn_field (arg1p, f, j, type, offset);
if (v != NULL)
return v;
}
else
while (j >= 0)
{
if (!typecmp (TYPE_FN_FIELD_STATIC_P (f, j),
TYPE_VARARGS (TYPE_FN_FIELD_TYPE (f, j)),
TYPE_NFIELDS (TYPE_FN_FIELD_TYPE (f, j)),
TYPE_FN_FIELD_ARGS (f, j), args))
{
if (TYPE_FN_FIELD_VIRTUAL_P (f, j))
return value_virtual_fn_field (arg1p, f, j,
type, offset);
if (TYPE_FN_FIELD_STATIC_P (f, j)
&& static_memfuncp)
*static_memfuncp = 1;
v = value_fn_field (arg1p, f, j, type, offset);
if (v != NULL)
return v;
}
j--;
}
}
}
for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
{
int base_offset;
int skip = 0;
int this_offset;
if (BASETYPE_VIA_VIRTUAL (type, i))
{
struct type *baseclass = check_typedef (TYPE_BASECLASS (type, i));
struct value *base_val;
const gdb_byte *base_valaddr;
/* The virtual base class pointer might have been
clobbered by the user program. Make sure that it
still points to a valid memory location. */
if (offset < 0 || offset >= TYPE_LENGTH (type))
{
gdb_byte *tmp = alloca (TYPE_LENGTH (baseclass));
CORE_ADDR address = value_address (*arg1p);
if (target_read_memory (address + offset,
tmp, TYPE_LENGTH (baseclass)) != 0)
error (_("virtual baseclass botch"));
base_val = value_from_contents_and_address (baseclass,
tmp,
address + offset);
base_valaddr = value_contents_for_printing (base_val);
this_offset = 0;
}
else
{
base_val = *arg1p;
base_valaddr = value_contents_for_printing (*arg1p);
this_offset = offset;
}
base_offset = baseclass_offset (type, i, base_valaddr,
this_offset, value_address (base_val),
base_val);
}
else
{
base_offset = TYPE_BASECLASS_BITPOS (type, i) / 8;
}
v = search_struct_method (name, arg1p, args, base_offset + offset,
static_memfuncp, TYPE_BASECLASS (type, i));
if (v == (struct value *) - 1)
{
name_matched = 1;
}
else if (v)
{
/* FIXME-bothner: Why is this commented out? Why is it here? */
/* *arg1p = arg1_tmp; */
return v;
}
}
if (name_matched)
return (struct value *) - 1;
else
return NULL;
}
/* Given *ARGP, a value of type (pointer to a)* structure/union,
extract the component named NAME from the ultimate target
structure/union and return it as a value with its appropriate type.
ERR is used in the error message if *ARGP's type is wrong.
C++: ARGS is a list of argument types to aid in the selection of
an appropriate method. Also, handle derived types.
STATIC_MEMFUNCP, if non-NULL, points to a caller-supplied location
where the truthvalue of whether the function that was resolved was
a static member function or not is stored.
ERR is an error message to be printed in case the field is not
found. */
struct value *
value_struct_elt (struct value **argp, struct value **args,
const char *name, int *static_memfuncp, const char *err)
{
struct type *t;
struct value *v;
*argp = coerce_array (*argp);
t = check_typedef (value_type (*argp));
/* Follow pointers until we get to a non-pointer. */
while (TYPE_CODE (t) == TYPE_CODE_PTR || TYPE_CODE (t) == TYPE_CODE_REF)
{
*argp = value_ind (*argp);
/* Don't coerce fn pointer to fn and then back again! */
if (TYPE_CODE (value_type (*argp)) != TYPE_CODE_FUNC)
*argp = coerce_array (*argp);
t = check_typedef (value_type (*argp));
}
if (TYPE_CODE (t) != TYPE_CODE_STRUCT
&& TYPE_CODE (t) != TYPE_CODE_UNION)
error (_("Attempt to extract a component of a value that is not a %s."),
err);
/* Assume it's not, unless we see that it is. */
if (static_memfuncp)
*static_memfuncp = 0;
if (!args)
{
/* if there are no arguments ...do this... */
/* Try as a field first, because if we succeed, there is less
work to be done. */
v = search_struct_field (name, *argp, 0, t, 0);
if (v)
return v;
/* C++: If it was not found as a data field, then try to
return it as a pointer to a method. */
v = search_struct_method (name, argp, args, 0,
static_memfuncp, t);
if (v == (struct value *) - 1)
error (_("Cannot take address of method %s."), name);
else if (v == 0)
{
if (TYPE_NFN_FIELDS (t))
error (_("There is no member or method named %s."), name);
else
error (_("There is no member named %s."), name);
}
return v;
}
v = search_struct_method (name, argp, args, 0,
static_memfuncp, t);
if (v == (struct value *) - 1)
{
error (_("One of the arguments you tried to pass to %s could not "
"be converted to what the function wants."), name);
}
else if (v == 0)
{
/* See if user tried to invoke data as function. If so, hand it
back. If it's not callable (i.e., a pointer to function),
gdb should give an error. */
v = search_struct_field (name, *argp, 0, t, 0);
/* If we found an ordinary field, then it is not a method call.
So, treat it as if it were a static member function. */
if (v && static_memfuncp)
*static_memfuncp = 1;
}
if (!v)
throw_error (NOT_FOUND_ERROR,
_("Structure has no component named %s."), name);
return v;
}
/* Search through the methods of an object (and its bases) to find a
specified method. Return the pointer to the fn_field list of
overloaded instances.
Helper function for value_find_oload_list.
ARGP is a pointer to a pointer to a value (the object).
METHOD is a string containing the method name.
OFFSET is the offset within the value.
TYPE is the assumed type of the object.
NUM_FNS is the number of overloaded instances.
BASETYPE is set to the actual type of the subobject where the
method is found.
BOFFSET is the offset of the base subobject where the method is found. */
static struct fn_field *
find_method_list (struct value **argp, const char *method,
int offset, struct type *type, int *num_fns,
struct type **basetype, int *boffset)
{
int i;
struct fn_field *f;
CHECK_TYPEDEF (type);
*num_fns = 0;
/* First check in object itself. */
for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; i--)
{
/* pai: FIXME What about operators and type conversions? */
const char *fn_field_name = TYPE_FN_FIELDLIST_NAME (type, i);
if (fn_field_name && (strcmp_iw (fn_field_name, method) == 0))
{
int len = TYPE_FN_FIELDLIST_LENGTH (type, i);
struct fn_field *f = TYPE_FN_FIELDLIST1 (type, i);
*num_fns = len;
*basetype = type;
*boffset = offset;
/* Resolve any stub methods. */
check_stub_method_group (type, i);
return f;
}
}
/* Not found in object, check in base subobjects. */
for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
{
int base_offset;
if (BASETYPE_VIA_VIRTUAL (type, i))
{
base_offset = baseclass_offset (type, i,
value_contents_for_printing (*argp),
value_offset (*argp) + offset,
value_address (*argp), *argp);
}
else /* Non-virtual base, simply use bit position from debug
info. */
{
base_offset = TYPE_BASECLASS_BITPOS (type, i) / 8;
}
f = find_method_list (argp, method, base_offset + offset,
TYPE_BASECLASS (type, i), num_fns,
basetype, boffset);
if (f)
return f;
}
return NULL;
}
/* Return the list of overloaded methods of a specified name.
ARGP is a pointer to a pointer to a value (the object).
METHOD is the method name.
OFFSET is the offset within the value contents.
NUM_FNS is the number of overloaded instances.
BASETYPE is set to the type of the base subobject that defines the
method.
BOFFSET is the offset of the base subobject which defines the method. */
static struct fn_field *
value_find_oload_method_list (struct value **argp, const char *method,
int offset, int *num_fns,
struct type **basetype, int *boffset)
{
struct type *t;
t = check_typedef (value_type (*argp));
/* Code snarfed from value_struct_elt. */
while (TYPE_CODE (t) == TYPE_CODE_PTR || TYPE_CODE (t) == TYPE_CODE_REF)
{
*argp = value_ind (*argp);
/* Don't coerce fn pointer to fn and then back again! */
if (TYPE_CODE (value_type (*argp)) != TYPE_CODE_FUNC)
*argp = coerce_array (*argp);
t = check_typedef (value_type (*argp));
}
if (TYPE_CODE (t) != TYPE_CODE_STRUCT
&& TYPE_CODE (t) != TYPE_CODE_UNION)
error (_("Attempt to extract a component of a "
"value that is not a struct or union"));
return find_method_list (argp, method, 0, t, num_fns,
basetype, boffset);
}
/* Given an array of arguments (ARGS) (which includes an
entry for "this" in the case of C++ methods), the number of
arguments NARGS, the NAME of a function whether it's a method or
not (METHOD), and the degree of laxness (LAX) in conforming to
overload resolution rules in ANSI C++, find the best function that
matches on the argument types according to the overload resolution
rules.
METHOD can be one of three values:
NON_METHOD for non-member functions.
METHOD: for member functions.
BOTH: used for overload resolution of operators where the
candidates are expected to be either member or non member
functions. In this case the first argument ARGTYPES
(representing 'this') is expected to be a reference to the
target object, and will be dereferenced when attempting the
non-member search.
In the case of class methods, the parameter OBJ is an object value
in which to search for overloaded methods.
In the case of non-method functions, the parameter FSYM is a symbol
corresponding to one of the overloaded functions.
Return value is an integer: 0 -> good match, 10 -> debugger applied
non-standard coercions, 100 -> incompatible.
If a method is being searched for, VALP will hold the value.
If a non-method is being searched for, SYMP will hold the symbol
for it.
If a method is being searched for, and it is a static method,
then STATICP will point to a non-zero value.
If NO_ADL argument dependent lookup is disabled. This is used to prevent
ADL overload candidates when performing overload resolution for a fully
qualified name.
Note: This function does *not* check the value of
overload_resolution. Caller must check it to see whether overload
resolution is permitted. */
int
find_overload_match (struct value **args, int nargs,
const char *name, enum oload_search_type method,
int lax, struct value **objp, struct symbol *fsym,
struct value **valp, struct symbol **symp,
int *staticp, const int no_adl)
{
struct value *obj = (objp ? *objp : NULL);
struct type *obj_type = obj ? value_type (obj) : NULL;
/* Index of best overloaded function. */
int func_oload_champ = -1;
int method_oload_champ = -1;
/* The measure for the current best match. */
struct badness_vector *method_badness = NULL;
struct badness_vector *func_badness = NULL;
struct value *temp = obj;
/* For methods, the list of overloaded methods. */
struct fn_field *fns_ptr = NULL;
/* For non-methods, the list of overloaded function symbols. */
struct symbol **oload_syms = NULL;
/* Number of overloaded instances being considered. */
int num_fns = 0;
struct type *basetype = NULL;
int boffset;
struct cleanup *all_cleanups = make_cleanup (null_cleanup, NULL);
const char *obj_type_name = NULL;
const char *func_name = NULL;
enum oload_classification match_quality;
enum oload_classification method_match_quality = INCOMPATIBLE;
enum oload_classification func_match_quality = INCOMPATIBLE;
/* Get the list of overloaded methods or functions. */
if (method == METHOD || method == BOTH)
{
gdb_assert (obj);
/* OBJ may be a pointer value rather than the object itself. */
obj = coerce_ref (obj);
while (TYPE_CODE (check_typedef (value_type (obj))) == TYPE_CODE_PTR)
obj = coerce_ref (value_ind (obj));
obj_type_name = TYPE_NAME (value_type (obj));
/* First check whether this is a data member, e.g. a pointer to
a function. */
if (TYPE_CODE (check_typedef (value_type (obj))) == TYPE_CODE_STRUCT)
{
*valp = search_struct_field (name, obj, 0,
check_typedef (value_type (obj)), 0);
if (*valp)
{
*staticp = 1;
do_cleanups (all_cleanups);
return 0;
}
}
/* Retrieve the list of methods with the name NAME. */
fns_ptr = value_find_oload_method_list (&temp, name,
0, &num_fns,
&basetype, &boffset);
/* If this is a method only search, and no methods were found
the search has faild. */
if (method == METHOD && (!fns_ptr || !num_fns))
error (_("Couldn't find method %s%s%s"),
obj_type_name,
(obj_type_name && *obj_type_name) ? "::" : "",
name);
/* If we are dealing with stub method types, they should have
been resolved by find_method_list via
value_find_oload_method_list above. */
if (fns_ptr)
{
gdb_assert (TYPE_DOMAIN_TYPE (fns_ptr[0].type) != NULL);
method_oload_champ = find_oload_champ (args, nargs, method,
num_fns, fns_ptr,
oload_syms, &method_badness);
method_match_quality =
classify_oload_match (method_badness, nargs,
oload_method_static (method, fns_ptr,
method_oload_champ));
make_cleanup (xfree, method_badness);
}
}
if (method == NON_METHOD || method == BOTH)
{
const char *qualified_name = NULL;
/* If the overload match is being search for both as a method
and non member function, the first argument must now be
dereferenced. */
if (method == BOTH)
args[0] = value_ind (args[0]);
if (fsym)
{
qualified_name = SYMBOL_NATURAL_NAME (fsym);
/* If we have a function with a C++ name, try to extract just
the function part. Do not try this for non-functions (e.g.
function pointers). */
if (qualified_name
&& TYPE_CODE (check_typedef (SYMBOL_TYPE (fsym)))
== TYPE_CODE_FUNC)
{
char *temp;
temp = cp_func_name (qualified_name);
/* If cp_func_name did not remove anything, the name of the
symbol did not include scope or argument types - it was
probably a C-style function. */
if (temp)
{
make_cleanup (xfree, temp);
if (strcmp (temp, qualified_name) == 0)
func_name = NULL;
else
func_name = temp;
}
}
}
else
{
func_name = name;
qualified_name = name;
}
/* If there was no C++ name, this must be a C-style function or
not a function at all. Just return the same symbol. Do the
same if cp_func_name fails for some reason. */
if (func_name == NULL)
{
*symp = fsym;
do_cleanups (all_cleanups);
return 0;
}
func_oload_champ = find_oload_champ_namespace (args, nargs,
func_name,
qualified_name,
&oload_syms,
&func_badness,
no_adl);
if (func_oload_champ >= 0)
func_match_quality = classify_oload_match (func_badness, nargs, 0);
make_cleanup (xfree, oload_syms);
make_cleanup (xfree, func_badness);
}
/* Did we find a match ? */
if (method_oload_champ == -1 && func_oload_champ == -1)
throw_error (NOT_FOUND_ERROR,
_("No symbol \"%s\" in current context."),
name);
/* If we have found both a method match and a function
match, find out which one is better, and calculate match
quality. */
if (method_oload_champ >= 0 && func_oload_champ >= 0)
{
switch (compare_badness (func_badness, method_badness))
{
case 0: /* Top two contenders are equally good. */
/* FIXME: GDB does not support the general ambiguous case.
All candidates should be collected and presented the
user. */
error (_("Ambiguous overload resolution"));
break;
case 1: /* Incomparable top contenders. */
/* This is an error incompatible candidates
should not have been proposed. */
error (_("Internal error: incompatible "
"overload candidates proposed"));
break;
case 2: /* Function champion. */
method_oload_champ = -1;
match_quality = func_match_quality;
break;
case 3: /* Method champion. */
func_oload_champ = -1;
match_quality = method_match_quality;
break;
default:
error (_("Internal error: unexpected overload comparison result"));
break;
}
}
else
{
/* We have either a method match or a function match. */
if (method_oload_champ >= 0)
match_quality = method_match_quality;
else
match_quality = func_match_quality;
}
if (match_quality == INCOMPATIBLE)
{
if (method == METHOD)
error (_("Cannot resolve method %s%s%s to any overloaded instance"),
obj_type_name,
(obj_type_name && *obj_type_name) ? "::" : "",
name);
else
error (_("Cannot resolve function %s to any overloaded instance"),
func_name);
}
else if (match_quality == NON_STANDARD)
{
if (method == METHOD)
warning (_("Using non-standard conversion to match "
"method %s%s%s to supplied arguments"),
obj_type_name,
(obj_type_name && *obj_type_name) ? "::" : "",
name);
else
warning (_("Using non-standard conversion to match "
"function %s to supplied arguments"),
func_name);
}