old-cross-binutils/gdb/jv-valprint.c
Pedro Alves 901461f8eb Print registers not saved in the frame as "<not saved>" instead of "<optimized out>".
Currently, in some scenarios, GDB prints <optimized out> when printing
outer frame registers.  An <optimized out> register is a confusing
concept.  What this really means is that the register is
call-clobbered, or IOW, not saved by the callee.  This patch makes GDB
say that instead.

Before patch:

 (gdb) p/x $rax $1 = <optimized out>
 (gdb) info registers rax
 rax            <optimized out>

After patch:

 (gdb) p/x $rax
 $1 = <not saved>
 (gdb) info registers rax
 rax            <not saved>

However, if for some reason the debug info describes a variable as
being in such a register (**), we still want to print <optimized out>
when printing the variable.  IOW, <not saved> is reserved for
inspecting registers at the machine level.  The patch uses
lval_register+optimized_out to encode the not saved registers, and
makes it so that optimized out variables always end up in
!lval_register values.

** See <https://sourceware.org/ml/gdb-patches/2012-08/msg00787.html>.
Current/recent enough GCC doesn't mark variables/arguments as being in
call-clobbered registers in the ranges corresponding to function
calls, while older GCCs did.  Newer GCCs will just not say where the
variable is, so GDB will end up realizing the variable is optimized
out.

frame_unwind_got_optimized creates not_lval optimized out registers,
so by default, in most cases, we'll see <optimized out>.

value_of_register is the function eval.c uses for evaluating
OP_REGISTER (again, $pc, etc.), and related bits.  It isn't used for
anything else.  This function makes sure to return lval_register
values.  The patch makes "info registers" and the MI equivalent use it
too.  I think it just makes a lot of sense, as this makes it so that
when printing machine registers ($pc, etc.), we go through a central
function.

We're likely to need a different encoding at some point, if/when we
support partially saved registers.  Even then, I think
value_of_register will still be the spot to tag the intention to print
machine register values differently.

value_from_register however may also return optimized out
lval_register values, so at a couple places where we're computing a
variable's location from a dwarf expression, we convert the resulting
value away from lval_register to a regular optimized out value.

Tested on x86_64 Fedora 17

gdb/
2013-10-02  Pedro Alves  <palves@redhat.com>

	* cp-valprint.c (cp_print_value_fields): Adjust calls to
	val_print_optimized_out.
	* jv-valprint.c (java_print_value_fields): Likewise.
	* p-valprint.c (pascal_object_print_value_fields): Likewise.
	* dwarf2loc.c (dwarf2_evaluate_loc_desc_full)
	<DWARF_VALUE_REGISTER>: If the register was not saved, return a
	new optimized out value.
	* findvar.c (address_from_register): Likewise.
	* frame.c (put_frame_register): Tweak error string to say the
	register was not saved, rather than optimized out.
	* infcmd.c (default_print_one_register_info): Adjust call to
	val_print_optimized_out.  Use value_of_register instead of
	get_frame_register_value.
	* mi/mi-main.c (output_register): Use value_of_register instead of
	get_frame_register_value.
	* valprint.c (valprint_check_validity): Likewise.
	(val_print_optimized_out): New value parameter.  If the value is
	lval_register, print <not saved> instead.
	(value_check_printable, val_print_scalar_formatted): Adjust calls
	to val_print_optimized_out.
	* valprint.h (val_print_optimized_out): New value parameter.
	* value.c (struct value) <optimized_out>: Extend comment.
	(error_value_optimized_out): New function.
	(require_not_optimized_out): Use it.  Use a different string for
	lval_register values.
	* value.h (error_value_optimized_out): New declaration.
	* NEWS: Mention <not saved>.

gdb/testsuite/
2013-10-02  Pedro Alves  <palves@redhat.com>

	* gdb.dwarf2/dw2-reg-undefined.exp <pattern_rax_rbx_rcx_print,
	pattern_rax_rbx_rcx_info>: Set to "<not saved>".
	* gdb.mi/mi-reg-undefined.exp (opt_out_pattern): Delete.
	(not_saved_pattern): New.
	Replace use of the former with the latter.

gdb/doc/
2013-10-02  Pedro Alves  <palves@redhat.com>

	* gdb.texinfo (Registers): Expand description of saved registers
	in frames.  Explain <not saved>.
2013-10-02 16:15:46 +00:00

543 lines
14 KiB
C

/* Support for printing Java values for GDB, the GNU debugger.
Copyright (C) 1997-2013 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 "gdbcore.h"
#include "expression.h"
#include "value.h"
#include "demangle.h"
#include "valprint.h"
#include "language.h"
#include "jv-lang.h"
#include "c-lang.h"
#include "annotate.h"
#include "gdb_string.h"
/* Local functions */
void
java_value_print (struct value *val, struct ui_file *stream,
const struct value_print_options *options)
{
struct gdbarch *gdbarch = get_type_arch (value_type (val));
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
struct type *type;
CORE_ADDR address;
int i;
const char *name;
struct value_print_options opts;
type = value_type (val);
address = value_address (val);
if (is_object_type (type))
{
CORE_ADDR obj_addr;
struct value *tem = val;
/* Get the run-time type, and cast the object into that. */
while (TYPE_CODE (value_type (tem)) == TYPE_CODE_PTR)
tem = value_ind (tem);
obj_addr = value_address (tem);
if (obj_addr != 0)
{
type = type_from_class (gdbarch, java_class_from_object (val));
type = lookup_pointer_type (type);
val = value_at (type, address);
}
}
if (TYPE_CODE (type) == TYPE_CODE_PTR && !value_logical_not (val))
type_print (TYPE_TARGET_TYPE (type), "", stream, -1);
name = TYPE_TAG_NAME (type);
if (TYPE_CODE (type) == TYPE_CODE_STRUCT && name != NULL
&& (i = strlen (name), name[i - 1] == ']'))
{
gdb_byte buf4[4];
long length;
unsigned int things_printed = 0;
int reps;
struct type *el_type
= java_primitive_type_from_name (gdbarch, name, i - 2);
i = 0;
read_memory (address + get_java_object_header_size (gdbarch), buf4, 4);
length = (long) extract_signed_integer (buf4, 4, byte_order);
fprintf_filtered (stream, "{length: %ld", length);
if (el_type == NULL)
{
CORE_ADDR element;
CORE_ADDR next_element = -1; /* Dummy initial value. */
/* Skip object header and length. */
address += get_java_object_header_size (gdbarch) + 4;
while (i < length && things_printed < options->print_max)
{
gdb_byte *buf;
buf = alloca (gdbarch_ptr_bit (gdbarch) / HOST_CHAR_BIT);
fputs_filtered (", ", stream);
wrap_here (n_spaces (2));
if (i > 0)
element = next_element;
else
{
read_memory (address, buf, sizeof (buf));
address += gdbarch_ptr_bit (gdbarch) / HOST_CHAR_BIT;
/* FIXME: cagney/2003-05-24: Bogus or what. It
pulls a host sized pointer out of the target and
then extracts that as an address (while assuming
that the address is unsigned)! */
element = extract_unsigned_integer (buf, sizeof (buf),
byte_order);
}
for (reps = 1; i + reps < length; reps++)
{
read_memory (address, buf, sizeof (buf));
address += gdbarch_ptr_bit (gdbarch) / HOST_CHAR_BIT;
/* FIXME: cagney/2003-05-24: Bogus or what. It
pulls a host sized pointer out of the target and
then extracts that as an address (while assuming
that the address is unsigned)! */
next_element = extract_unsigned_integer (buf, sizeof (buf),
byte_order);
if (next_element != element)
break;
}
if (reps == 1)
fprintf_filtered (stream, "%d: ", i);
else
fprintf_filtered (stream, "%d..%d: ", i, i + reps - 1);
if (element == 0)
fprintf_filtered (stream, "null");
else
fprintf_filtered (stream, "@%s", paddress (gdbarch, element));
things_printed++;
i += reps;
}
}
else
{
struct value *v = allocate_value (el_type);
struct value *next_v = allocate_value (el_type);
set_value_address (v, (address
+ get_java_object_header_size (gdbarch) + 4));
set_value_address (next_v, value_raw_address (v));
while (i < length && things_printed < options->print_max)
{
fputs_filtered (", ", stream);
wrap_here (n_spaces (2));
if (i > 0)
{
struct value *tmp;
tmp = next_v;
next_v = v;
v = tmp;
}
else
{
set_value_lazy (v, 1);
set_value_offset (v, 0);
}
set_value_offset (next_v, value_offset (v));
for (reps = 1; i + reps < length; reps++)
{
set_value_lazy (next_v, 1);
set_value_offset (next_v, value_offset (next_v)
+ TYPE_LENGTH (el_type));
value_fetch_lazy (next_v);
if (!(value_available_contents_eq
(v, value_embedded_offset (v),
next_v, value_embedded_offset (next_v),
TYPE_LENGTH (el_type))))
break;
}
if (reps == 1)
fprintf_filtered (stream, "%d: ", i);
else
fprintf_filtered (stream, "%d..%d: ", i, i + reps - 1);
opts = *options;
opts.deref_ref = 1;
common_val_print (v, stream, 1, &opts, current_language);
things_printed++;
i += reps;
}
}
if (i < length)
fprintf_filtered (stream, "...");
fprintf_filtered (stream, "}");
return;
}
/* If it's type String, print it. */
if (TYPE_CODE (type) == TYPE_CODE_PTR
&& TYPE_TARGET_TYPE (type)
&& TYPE_TAG_NAME (TYPE_TARGET_TYPE (type))
&& strcmp (TYPE_TAG_NAME (TYPE_TARGET_TYPE (type)),
"java.lang.String") == 0
&& (options->format == 0 || options->format == 's')
&& address != 0
&& value_as_address (val) != 0)
{
struct type *char_type;
struct value *data_val;
CORE_ADDR data;
struct value *boffset_val;
unsigned long boffset;
struct value *count_val;
unsigned long count;
struct value *mark;
fputs_filtered (" ", stream);
mark = value_mark (); /* Remember start of new values. */
data_val = value_struct_elt (&val, NULL, "data", NULL, NULL);
data = value_as_address (data_val);
boffset_val = value_struct_elt (&val, NULL, "boffset", NULL, NULL);
boffset = value_as_address (boffset_val);
count_val = value_struct_elt (&val, NULL, "count", NULL, NULL);
count = value_as_address (count_val);
value_free_to_mark (mark); /* Release unnecessary values. */
char_type = builtin_java_type (gdbarch)->builtin_char;
val_print_string (char_type, NULL, data + boffset, count, stream,
options);
return;
}
opts = *options;
opts.deref_ref = 1;
common_val_print (val, stream, 0, &opts, current_language);
}
/* TYPE, VALADDR, ADDRESS, STREAM, RECURSE, and OPTIONS have the
same meanings as in cp_print_value and c_val_print.
DONT_PRINT is an array of baseclass types that we
should not print, or zero if called from top level. */
static void
java_print_value_fields (struct type *type, const gdb_byte *valaddr,
int offset,
CORE_ADDR address, struct ui_file *stream,
int recurse,
const struct value *val,
const struct value_print_options *options)
{
int i, len, n_baseclasses;
CHECK_TYPEDEF (type);
fprintf_filtered (stream, "{");
len = TYPE_NFIELDS (type);
n_baseclasses = TYPE_N_BASECLASSES (type);
if (n_baseclasses > 0)
{
int i, n_baseclasses = TYPE_N_BASECLASSES (type);
for (i = 0; i < n_baseclasses; i++)
{
int boffset;
struct type *baseclass = check_typedef (TYPE_BASECLASS (type, i));
const char *basename = TYPE_NAME (baseclass);
const gdb_byte *base_valaddr;
if (BASETYPE_VIA_VIRTUAL (type, i))
continue;
if (basename != NULL && strcmp (basename, "java.lang.Object") == 0)
continue;
boffset = 0;
if (options->prettyformat)
{
fprintf_filtered (stream, "\n");
print_spaces_filtered (2 * (recurse + 1), stream);
}
fputs_filtered ("<", stream);
/* Not sure what the best notation is in the case where there is no
baseclass name. */
fputs_filtered (basename ? basename : "", stream);
fputs_filtered ("> = ", stream);
base_valaddr = valaddr;
java_print_value_fields (baseclass, base_valaddr,
offset + boffset, address,
stream, recurse + 1, val, options);
fputs_filtered (", ", stream);
}
}
if (!len && n_baseclasses == 1)
fprintf_filtered (stream, "<No data fields>");
else
{
int fields_seen = 0;
for (i = n_baseclasses; i < len; i++)
{
/* If requested, skip printing of static fields. */
if (field_is_static (&TYPE_FIELD (type, i)))
{
const char *name = TYPE_FIELD_NAME (type, i);
if (!options->static_field_print)
continue;
if (name != NULL && strcmp (name, "class") == 0)
continue;
}
if (fields_seen)
fprintf_filtered (stream, ", ");
else if (n_baseclasses > 0)
{
if (options->prettyformat)
{
fprintf_filtered (stream, "\n");
print_spaces_filtered (2 + 2 * recurse, stream);
fputs_filtered ("members of ", stream);
fputs_filtered (type_name_no_tag (type), stream);
fputs_filtered (": ", stream);
}
}
fields_seen = 1;
if (options->prettyformat)
{
fprintf_filtered (stream, "\n");
print_spaces_filtered (2 + 2 * recurse, stream);
}
else
{
wrap_here (n_spaces (2 + 2 * recurse));
}
annotate_field_begin (TYPE_FIELD_TYPE (type, i));
if (field_is_static (&TYPE_FIELD (type, i)))
fputs_filtered ("static ", stream);
fprintf_symbol_filtered (stream, TYPE_FIELD_NAME (type, i),
language_cplus,
DMGL_PARAMS | DMGL_ANSI);
annotate_field_name_end ();
fputs_filtered (": ", stream);
annotate_field_value ();
if (!field_is_static (&TYPE_FIELD (type, i))
&& TYPE_FIELD_PACKED (type, i))
{
struct value *v;
/* Bitfields require special handling, especially due to byte
order problems. */
if (TYPE_FIELD_IGNORE (type, i))
{
fputs_filtered ("<optimized out or zero length>", stream);
}
else if (value_bits_synthetic_pointer (val,
TYPE_FIELD_BITPOS (type,
i),
TYPE_FIELD_BITSIZE (type,
i)))
{
fputs_filtered (_("<synthetic pointer>"), stream);
}
else if (!value_bits_valid (val, TYPE_FIELD_BITPOS (type, i),
TYPE_FIELD_BITSIZE (type, i)))
{
val_print_optimized_out (val, stream);
}
else
{
struct value_print_options opts;
v = value_field_bitfield (type, i, valaddr, offset, val);
opts = *options;
opts.deref_ref = 0;
common_val_print (v, stream, recurse + 1,
&opts, current_language);
}
}
else
{
if (TYPE_FIELD_IGNORE (type, i))
{
fputs_filtered ("<optimized out or zero length>", stream);
}
else if (field_is_static (&TYPE_FIELD (type, i)))
{
struct value *v = value_static_field (type, i);
if (v == NULL)
val_print_optimized_out (NULL, stream);
else
{
struct value_print_options opts;
struct type *t = check_typedef (value_type (v));
if (TYPE_CODE (t) == TYPE_CODE_STRUCT)
v = value_addr (v);
opts = *options;
opts.deref_ref = 0;
common_val_print (v, stream, recurse + 1,
&opts, current_language);
}
}
else if (TYPE_FIELD_TYPE (type, i) == NULL)
fputs_filtered ("<unknown type>", stream);
else
{
struct value_print_options opts = *options;
opts.deref_ref = 0;
val_print (TYPE_FIELD_TYPE (type, i),
valaddr,
offset + TYPE_FIELD_BITPOS (type, i) / 8,
address, stream, recurse + 1, val, &opts,
current_language);
}
}
annotate_field_end ();
}
if (options->prettyformat)
{
fprintf_filtered (stream, "\n");
print_spaces_filtered (2 * recurse, stream);
}
}
fprintf_filtered (stream, "}");
}
/* See val_print for a description of the various parameters of this
function; they are identical. */
void
java_val_print (struct type *type, const gdb_byte *valaddr,
int embedded_offset, CORE_ADDR address,
struct ui_file *stream, int recurse,
const struct value *val,
const struct value_print_options *options)
{
struct gdbarch *gdbarch = get_type_arch (type);
struct type *target_type;
CORE_ADDR addr;
CHECK_TYPEDEF (type);
switch (TYPE_CODE (type))
{
case TYPE_CODE_PTR:
if (options->format && options->format != 's')
{
val_print_scalar_formatted (type, valaddr, embedded_offset,
val, options, 0, stream);
break;
}
addr = unpack_pointer (type, valaddr + embedded_offset);
if (addr == 0)
{
fputs_filtered ("null", stream);
return;
}
target_type = check_typedef (TYPE_TARGET_TYPE (type));
if (TYPE_CODE (target_type) == TYPE_CODE_FUNC)
{
/* Try to print what function it points to. */
print_address_demangle (options, gdbarch, addr, stream, demangle);
return;
}
if (options->addressprint && options->format != 's')
{
fputs_filtered ("@", stream);
print_longest (stream, 'x', 0, (ULONGEST) addr);
}
return;
case TYPE_CODE_CHAR:
case TYPE_CODE_INT:
/* Can't just call c_val_print because that prints bytes as C
chars. */
if (options->format || options->output_format)
{
struct value_print_options opts = *options;
opts.format = (options->format ? options->format
: options->output_format);
val_print_scalar_formatted (type, valaddr, embedded_offset,
val, &opts, 0, stream);
}
else if (TYPE_CODE (type) == TYPE_CODE_CHAR
|| (TYPE_CODE (type) == TYPE_CODE_INT
&& TYPE_LENGTH (type) == 2
&& strcmp (TYPE_NAME (type), "char") == 0))
LA_PRINT_CHAR ((int) unpack_long (type, valaddr + embedded_offset),
type, stream);
else
val_print_type_code_int (type, valaddr + embedded_offset, stream);
break;
case TYPE_CODE_STRUCT:
java_print_value_fields (type, valaddr, embedded_offset,
address, stream, recurse, val, options);
break;
default:
c_val_print (type, valaddr, embedded_offset, address, stream,
recurse, val, options);
break;
}
}