#include "defs.h"
#include "arch-utils.h"
-#include "gdb_string.h"
+#include <string.h>
#include "symtab.h"
#include "gdbtypes.h"
#include "value.h"
#include <ctype.h>
#include "tracepoint.h"
#include "cp-abi.h"
+#include "user-regs.h"
/* Prototypes for exported functions. */
reset, be sure to consider this use as well! */
unsigned int lazy : 1;
- /* If nonzero, this is the value of a variable which does not
- actually exist in the program. */
+ /* If nonzero, this is the value of a variable that does not
+ actually exist in the program. If nonzero, and LVAL is
+ lval_register, this is a register ($pc, $sp, etc., never a
+ program variable) that has not been saved in the frame. All
+ optimized-out values are treated pretty much the same, except
+ registers have a different string representation and related
+ error strings. */
unsigned int optimized_out : 1;
/* If value is a variable, is it initialized or not. */
return 0;
}
+int
+value_entirely_unavailable (struct value *value)
+{
+ /* We can only tell whether the whole value is available when we try
+ to read it. */
+ if (value->lazy)
+ value_fetch_lazy (value);
+
+ if (VEC_length (range_s, value->unavailable) == 1)
+ {
+ struct range *t = VEC_index (range_s, value->unavailable, 0);
+
+ if (t->offset == 0
+ && t->length == TYPE_LENGTH (value_enclosing_type (value)))
+ return 1;
+ }
+
+ return 0;
+}
+
void
mark_value_bytes_unavailable (struct value *value, int offset, int length)
{
{
int idx1 = 0, idx2 = 0;
- /* This routine is used by printing routines, where we should
- already have read the value. Note that we only know whether a
- value chunk is available if we've tried to read it. */
+ /* See function description in value.h. */
gdb_assert (!val1->lazy && !val2->lazy);
while (length > 0)
/* Allocate the contents of VAL if it has not been allocated yet. */
-void
+static void
allocate_value_contents (struct value *val)
{
if (!val->contents)
struct value *retval = allocate_value_lazy (type);
set_value_optimized_out (retval, 1);
-
+ set_value_lazy (retval, 0);
return retval;
}
void
set_value_parent (struct value *value, struct value *parent)
{
+ struct value *old = value->parent;
+
value->parent = parent;
+ if (parent != NULL)
+ value_incref (parent);
+ value_free (old);
}
gdb_byte *
return result;
}
+void
+error_value_optimized_out (void)
+{
+ error (_("value has been optimized out"));
+}
+
static void
require_not_optimized_out (const struct value *value)
{
if (value->optimized_out)
- error (_("value has been optimized out"));
+ {
+ if (value->lval == lval_register)
+ error (_("register has not been saved in frame"));
+ else
+ error_value_optimized_out ();
+ }
}
static void
int
value_optimized_out (struct value *value)
+{
+ /* We can only know if a value is optimized out once we have tried to
+ fetch it. */
+ if (!value->optimized_out && value->lazy)
+ value_fetch_lazy (value);
+
+ return value->optimized_out;
+}
+
+int
+value_optimized_out_const (const struct value *value)
{
return value->optimized_out;
}
{
return value->modifiable;
}
-void
-deprecated_set_value_modifiable (struct value *value, int modifiable)
-{
- value->modifiable = modifiable;
-}
\f
/* Return a mark in the value chain. All values allocated after the
mark is obtained (except for those released) are subject to being freed
}
val->unavailable = VEC_copy (range_s, arg->unavailable);
- val->parent = arg->parent;
- if (val->parent)
- value_incref (val->parent);
+ set_value_parent (val, arg->parent);
if (VALUE_LVAL (val) == lval_computed)
{
const struct lval_funcs *funcs = val->location.computed.funcs;
static void
function_destroyer (struct cmd_list_element *self, void *ignore)
{
- xfree (self->name);
+ xfree ((char *) self->name);
xfree (self->doc);
}
\f
/* Get the value of the FIELDNO'th field (which must be static) of
- TYPE. Return NULL if the field doesn't exist or has been
- optimized out. */
+ TYPE. */
struct value *
value_static_field (struct type *type, int fieldno)
NULL, NULL);
if (!msym)
- return NULL;
+ return allocate_optimized_out_value (type);
else
{
retval = value_at_lazy (TYPE_FIELD_TYPE (type, fieldno),
description correctly. */
check_typedef (type);
- if (value_optimized_out (arg1))
- v = allocate_optimized_out_value (type);
- else if (TYPE_FIELD_BITSIZE (arg_type, fieldno))
+ if (TYPE_FIELD_BITSIZE (arg_type, fieldno))
{
/* Handle packed fields.
int bitpos = TYPE_FIELD_BITPOS (arg_type, fieldno);
int container_bitsize = TYPE_LENGTH (type) * 8;
- v = allocate_value_lazy (type);
- v->bitsize = TYPE_FIELD_BITSIZE (arg_type, fieldno);
- if ((bitpos % container_bitsize) + v->bitsize <= container_bitsize
- && TYPE_LENGTH (type) <= (int) sizeof (LONGEST))
- v->bitpos = bitpos % container_bitsize;
+ if (arg1->optimized_out)
+ v = allocate_optimized_out_value (type);
else
- v->bitpos = bitpos % 8;
- v->offset = (value_embedded_offset (arg1)
- + offset
- + (bitpos - v->bitpos) / 8);
- v->parent = arg1;
- value_incref (v->parent);
- if (!value_lazy (arg1))
- value_fetch_lazy (v);
+ {
+ v = allocate_value_lazy (type);
+ v->bitsize = TYPE_FIELD_BITSIZE (arg_type, fieldno);
+ if ((bitpos % container_bitsize) + v->bitsize <= container_bitsize
+ && TYPE_LENGTH (type) <= (int) sizeof (LONGEST))
+ v->bitpos = bitpos % container_bitsize;
+ else
+ v->bitpos = bitpos % 8;
+ v->offset = (value_embedded_offset (arg1)
+ + offset
+ + (bitpos - v->bitpos) / 8);
+ set_value_parent (v, arg1);
+ if (!value_lazy (arg1))
+ value_fetch_lazy (v);
+ }
}
else if (fieldno < TYPE_N_BASECLASSES (arg_type))
{
if (VALUE_LVAL (arg1) == lval_register && value_lazy (arg1))
value_fetch_lazy (arg1);
- /* We special case virtual inheritance here because this
- requires access to the contents, which we would rather avoid
- for references to ordinary fields of unavailable values. */
- if (BASETYPE_VIA_VIRTUAL (arg_type, fieldno))
- boffset = baseclass_offset (arg_type, fieldno,
- value_contents (arg1),
- value_embedded_offset (arg1),
- value_address (arg1),
- arg1);
- else
- boffset = TYPE_FIELD_BITPOS (arg_type, fieldno) / 8;
-
- if (value_lazy (arg1))
- v = allocate_value_lazy (value_enclosing_type (arg1));
+ /* The optimized_out flag is only set correctly once a lazy value is
+ loaded, having just loaded some lazy values we should check the
+ optimized out case now. */
+ if (arg1->optimized_out)
+ v = allocate_optimized_out_value (type);
else
{
- v = allocate_value (value_enclosing_type (arg1));
- value_contents_copy_raw (v, 0, arg1, 0,
- TYPE_LENGTH (value_enclosing_type (arg1)));
+ /* We special case virtual inheritance here because this
+ requires access to the contents, which we would rather avoid
+ for references to ordinary fields of unavailable values. */
+ if (BASETYPE_VIA_VIRTUAL (arg_type, fieldno))
+ boffset = baseclass_offset (arg_type, fieldno,
+ value_contents (arg1),
+ value_embedded_offset (arg1),
+ value_address (arg1),
+ arg1);
+ else
+ boffset = TYPE_FIELD_BITPOS (arg_type, fieldno) / 8;
+
+ if (value_lazy (arg1))
+ v = allocate_value_lazy (value_enclosing_type (arg1));
+ else
+ {
+ v = allocate_value (value_enclosing_type (arg1));
+ value_contents_copy_raw (v, 0, arg1, 0,
+ TYPE_LENGTH (value_enclosing_type (arg1)));
+ }
+ v->type = type;
+ v->offset = value_offset (arg1);
+ v->embedded_offset = offset + value_embedded_offset (arg1) + boffset;
}
- v->type = type;
- v->offset = value_offset (arg1);
- v->embedded_offset = offset + value_embedded_offset (arg1) + boffset;
}
else
{
if (VALUE_LVAL (arg1) == lval_register && value_lazy (arg1))
value_fetch_lazy (arg1);
- if (value_lazy (arg1))
+ /* The optimized_out flag is only set correctly once a lazy value is
+ loaded, having just loaded some lazy values we should check for
+ the optimized out case now. */
+ if (arg1->optimized_out)
+ v = allocate_optimized_out_value (type);
+ else if (value_lazy (arg1))
v = allocate_value_lazy (type);
else
{
struct type *ftype = TYPE_FN_FIELD_TYPE (f, j);
const char *physname = TYPE_FN_FIELD_PHYSNAME (f, j);
struct symbol *sym;
- struct minimal_symbol *msym;
+ struct bound_minimal_symbol msym;
sym = lookup_symbol (physname, 0, VAR_DOMAIN, 0);
if (sym != NULL)
{
- msym = NULL;
+ memset (&msym, 0, sizeof (msym));
}
else
{
gdb_assert (sym == NULL);
- msym = lookup_minimal_symbol (physname, NULL, NULL);
- if (msym == NULL)
+ msym = lookup_bound_minimal_symbol (physname);
+ if (msym.minsym == NULL)
return NULL;
}
{
/* The minimal symbol might point to a function descriptor;
resolve it to the actual code address instead. */
- struct objfile *objfile = msymbol_objfile (msym);
+ struct objfile *objfile = msym.objfile;
struct gdbarch *gdbarch = get_objfile_arch (objfile);
set_value_address (v,
gdbarch_convert_from_func_ptr_addr
- (gdbarch, SYMBOL_VALUE_ADDRESS (msym), ¤t_target));
+ (gdbarch, SYMBOL_VALUE_ADDRESS (msym.minsym), ¤t_target));
}
if (arg1p)
if (valaddr == NULL)
v = allocate_value_lazy (type);
else
- {
- v = allocate_value (type);
- memcpy (value_contents_raw (v), valaddr, TYPE_LENGTH (type));
- }
+ v = value_from_contents (type, valaddr);
set_value_address (v, address);
VALUE_LVAL (v) = lval_memory;
return v;
}
\f
+/* Return the return value convention that will be used for the
+ specified type. */
+
+enum return_value_convention
+struct_return_convention (struct gdbarch *gdbarch,
+ struct value *function, struct type *value_type)
+{
+ enum type_code code = TYPE_CODE (value_type);
+
+ if (code == TYPE_CODE_ERROR)
+ error (_("Function return type unknown."));
+
+ /* Probe the architecture for the return-value convention. */
+ return gdbarch_return_value (gdbarch, function, value_type,
+ NULL, NULL, NULL);
+}
+
/* Return true if the function returning the specified type is using
the convention of returning structures in memory (passing in the
address as a hidden first parameter). */
using_struct_return (struct gdbarch *gdbarch,
struct value *function, struct type *value_type)
{
- enum type_code code = TYPE_CODE (value_type);
-
- if (code == TYPE_CODE_ERROR)
- error (_("Function return type unknown."));
-
- if (code == TYPE_CODE_VOID)
+ if (TYPE_CODE (value_type) == TYPE_CODE_VOID)
/* A void return value is never in memory. See also corresponding
code in "print_return_value". */
return 0;
- /* Probe the architecture for the return-value convention. */
- return (gdbarch_return_value (gdbarch, function, value_type,
- NULL, NULL, NULL)
+ return (struct_return_convention (gdbarch, function, value_type)
!= RETURN_VALUE_REGISTER_CONVENTION);
}
return val->initialized;
}
+/* 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;
+
+ if (value_lazy (parent))
+ value_fetch_lazy (parent);
+
+ if (!value_bits_valid (parent,
+ TARGET_CHAR_BIT * offset + value_bitpos (val),
+ value_bitsize (val)))
+ set_value_optimized_out (val, 1);
+ else 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),
+ TYPE_LENGTH (type));
+ else
+ store_signed_integer (value_contents_raw (val), TYPE_LENGTH (type),
+ byte_order, num);
+ }
+ else if (VALUE_LVAL (val) == lval_memory)
+ {
+ CORE_ADDR addr = value_address (val);
+ struct type *type = check_typedef (value_enclosing_type (val));
+
+ if (TYPE_LENGTH (type))
+ read_value_memory (val, 0, value_stack (val),
+ addr, value_contents_all_raw (val),
+ TYPE_LENGTH (type));
+ }
+ 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))
+ {
+ struct frame_id frame_id = VALUE_FRAME_ID (new_val);
+
+ frame = frame_find_by_id (frame_id);
+ 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 we get another lazy lval_register value, it means the
+ register is found by reading it from the next frame.
+ get_frame_register_value should never return a value with
+ the frame id pointing to FRAME. If it does, it means we
+ either have two consecutive frames with the same frame id
+ in the frame chain, or some code is trying to unwind
+ behind get_prev_frame's back (e.g., a frame unwind
+ sniffer trying to unwind), bypassing its validations. In
+ any case, it should always be an internal error to end up
+ in this situation. */
+ if (VALUE_LVAL (new_val) == lval_register
+ && value_lazy (new_val)
+ && frame_id_eq (VALUE_FRAME_ID (new_val), frame_id))
+ internal_error (__FILE__, __LINE__,
+ _("infinite loop while fetching a register"));
+ }
+
+ /* 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, " ");
+ val_print_optimized_out (new_val, gdb_stdlog);
+ }
+ 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);
+ /* Don't call value_optimized_out on val, doing so would result in a
+ recursive call back to value_fetch_lazy, instead check the
+ optimized_out flag directly. */
+ else if (val->optimized_out)
+ /* Keep it optimized out. */;
+ else
+ internal_error (__FILE__, __LINE__, _("Unexpected lazy value type."));
+
+ set_value_lazy (val, 0);
+ return 0;
+}
+
+/* Implementation of the convenience function $_isvoid. */
+
+static struct value *
+isvoid_internal_fn (struct gdbarch *gdbarch,
+ const struct language_defn *language,
+ void *cookie, int argc, struct value **argv)
+{
+ int ret;
+
+ if (argc != 1)
+ error (_("You must provide one argument for $_isvoid."));
+
+ ret = TYPE_CODE (value_type (argv[0])) == TYPE_CODE_VOID;
+
+ return value_from_longest (builtin_type (gdbarch)->builtin_int, ret);
+}
+
void
_initialize_values (void)
{
add_prefix_cmd ("function", no_class, function_command, _("\
Placeholder command for showing help on convenience functions."),
&functionlist, "function ", 0, &cmdlist);
+
+ add_internal_function ("_isvoid", _("\
+Check whether an expression is void.\n\
+Usage: $_isvoid (expression)\n\
+Return 1 if the expression is void, zero otherwise."),
+ isvoid_internal_fn, NULL);
}
projects / deliverable / binutils-gdb.git / blobdiff