binutils-gdb/gdb/ada-valprint.c
Joel Brobecker eccab96d54 improved error message when getting an exception printing a variable
Consider the following Ada code defining a global variable whose
type is an array of static bounds (1 .. 2), but where its elements
are a variant record whose size is not statically known:

    type Ints is array (Natural range <>) of Integer;
    type Bounded_Ints (Max_Size : Natural) is record
       Length : Natural := 0;
       Objs   : Ints (1 .. Max_Size);
    end record;

    type Ints_Doubled is array (1 .. 2) of Bounded_Ints (Idem (0));

    Global : Ints_Doubled;

When compiling this program at -O2 using a GCC-6.4-based compiler
on x86_64-linux, trying to print the value of that global variable
yields:

    (gdb) p global
    $1 =

Let's look at the debugging info, which starts with the global
variable itself...

        .uleb128 0x19   # (DIE (0x25e) DW_TAG_variable)
        .long   .LASF32 # DW_AT_name: "fd__global"
        .long   0x273   # DW_AT_type

... its type is a reference to a typedef ...

        .uleb128 0x14   # (DIE (0x273) DW_TAG_reference_type)
        .byte   0x8     # DW_AT_byte_size
        .long   0x202   # DW_AT_type
        [...]
        .uleb128 0x15   # (DIE (0x202) DW_TAG_typedef)
        .long   .LASF19 # DW_AT_name: "fd__ints_doubled"
        .long   0x20d   # DW_AT_type

... of an array (1..2) ...

        .uleb128 0x2    # (DIE (0x20d) DW_TAG_array_type)
        .long   .LASF19 # DW_AT_name: "fd__ints_doubled"
        .long   0x15b   # DW_AT_type
        .long   0x221   # DW_AT_sibling
        .uleb128 0x16   # (DIE (0x21a) DW_TAG_subrange_type)
        .long   0x40    # DW_AT_type
        .sleb128 2      # DW_AT_upper_bound
        .byte   0       # end of children of DIE 0x20d

... of a struct whose name is fd__Tints_doubledC:

        .uleb128 0x10   # (DIE (0x15b) DW_TAG_structure_type)
        .long   .LASF11 # DW_AT_name: "fd__Tints_doubledC"
        .long   0x1e4   # DW_AT_GNAT_descriptive_type
                        # DW_AT_artificial
        .long   0x1e4   # DW_AT_sibling
        .uleb128 0x7    # (DIE (0x16a) DW_TAG_member)
        .long   .LASF4  # DW_AT_name: "max_size"
        [snip]

The error occurs while Ada evaluator is trying to "fix"
the element type inside the array, so as to determine its actual
size. For that, it searches for a parallel "XVZ" variable,
which, when found, contains the object's actual size.

Unfortunately in our case, the variable exists but has been
optimized out, as seen by the presence of a variable DIE in
the debugging info, but with no address attribute:

        .uleb128 0x18   # (DIE (0x24e) DW_TAG_variable)
        .long   .LASF31 # DW_AT_name: "fd__Tints_doubledC___XVZ"
        .long   0x257   # DW_AT_type
                        # DW_AT_artificial

Discussing this with some members of AdaCore's compiler team,
it is expected that the optimizer can get rid of this variable,
and we don't want to pessimize the code just to improve debuggability,
since -O2 is about performance. So, the idea of this patch is
not to make it work, but provide a bit more information to help
users understand what kind of error is preventing GDB from being
able to print the variable's value.

The first hurdle we had to clear was the fact that ada_val_print
traps all exceptions (including QUIT ones!), and does so completly
silently. So, the fix was to add a trace of the exception being
generated. While doing so, we fix an old XXX/FIXME by only catching
errors, letting QUIT exceptions go through.

Once this is done, we now get an error message, which gives a first
clue as to what was happening:

    (gdb) p fd.global
    $1 = <error reading variable: value has been optimized out>

However, it would be more useful to know which value it was
that was optimized out. For that purpose, we enhanced
ada-lang.c::ada_to_fixed_type_1 so as to re-throw the error
with a message which indicates which variable we failed to read.

With those changes, the new output is now:

    (gdb) p fd.global
    $1 = <error reading variable: unable to read value of fd__Tints_doubledC___XVZ (value has been optimized out)>

gdb/ChangeLog:

        * ada-lang.c (ada_to_fixed_type_1): Rethrow errors with
        a more detailed exception message when getting an exception
        while trying to read the value of an XVZ variable.
        * ada-valprint.c (ada_val_print): Only catch RETURN_MASK_ERROR
        exceptions.  Print an error message when an exception is caught.

gdb/testsuite/ChangeLog:

        * gdb.dwarf2/ada-valprint-error.c: New file.
        * gdb.dwarf2/ada-valprint-error.exp: New file.

Tested on x86_64-linux
2017-12-17 22:39:33 -05:00

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/* Support for printing Ada values for GDB, the GNU debugger.
Copyright (C) 1986-2017 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 <ctype.h>
#include "symtab.h"
#include "gdbtypes.h"
#include "expression.h"
#include "value.h"
#include "demangle.h"
#include "valprint.h"
#include "language.h"
#include "annotate.h"
#include "ada-lang.h"
#include "c-lang.h"
#include "infcall.h"
#include "objfiles.h"
#include "target-float.h"
static int print_field_values (struct type *, const gdb_byte *,
int,
struct ui_file *, int,
struct value *,
const struct value_print_options *,
int, struct type *, int,
const struct language_defn *);
/* Make TYPE unsigned if its range of values includes no negatives. */
static void
adjust_type_signedness (struct type *type)
{
if (type != NULL && TYPE_CODE (type) == TYPE_CODE_RANGE
&& TYPE_LOW_BOUND (type) >= 0)
TYPE_UNSIGNED (type) = 1;
}
/* Assuming TYPE is a simple array type, prints its lower bound on STREAM,
if non-standard (i.e., other than 1 for numbers, other than lower bound
of index type for enumerated type). Returns 1 if something printed,
otherwise 0. */
static int
print_optional_low_bound (struct ui_file *stream, struct type *type,
const struct value_print_options *options)
{
struct type *index_type;
LONGEST low_bound;
LONGEST high_bound;
if (options->print_array_indexes)
return 0;
if (!get_array_bounds (type, &low_bound, &high_bound))
return 0;
/* If this is an empty array, then don't print the lower bound.
That would be confusing, because we would print the lower bound,
followed by... nothing! */
if (low_bound > high_bound)
return 0;
index_type = TYPE_INDEX_TYPE (type);
while (TYPE_CODE (index_type) == TYPE_CODE_RANGE)
{
/* We need to know what the base type is, in order to do the
appropriate check below. Otherwise, if this is a subrange
of an enumerated type, where the underlying value of the
first element is typically 0, we might test the low bound
against the wrong value. */
index_type = TYPE_TARGET_TYPE (index_type);
}
switch (TYPE_CODE (index_type))
{
case TYPE_CODE_BOOL:
if (low_bound == 0)
return 0;
break;
case TYPE_CODE_ENUM:
if (low_bound == TYPE_FIELD_ENUMVAL (index_type, 0))
return 0;
break;
case TYPE_CODE_UNDEF:
index_type = NULL;
/* FALL THROUGH */
default:
if (low_bound == 1)
return 0;
break;
}
ada_print_scalar (index_type, low_bound, stream);
fprintf_filtered (stream, " => ");
return 1;
}
/* Version of val_print_array_elements for GNAT-style packed arrays.
Prints elements of packed array of type TYPE at bit offset
BITOFFSET from VALADDR on STREAM. Formats according to OPTIONS and
separates with commas. RECURSE is the recursion (nesting) level.
TYPE must have been decoded (as by ada_coerce_to_simple_array). */
static void
val_print_packed_array_elements (struct type *type, const gdb_byte *valaddr,
int offset,
int bitoffset, struct ui_file *stream,
int recurse,
struct value *val,
const struct value_print_options *options)
{
unsigned int i;
unsigned int things_printed = 0;
unsigned len;
struct type *elttype, *index_type;
unsigned long bitsize = TYPE_FIELD_BITSIZE (type, 0);
struct value *mark = value_mark ();
LONGEST low = 0;
elttype = TYPE_TARGET_TYPE (type);
index_type = TYPE_INDEX_TYPE (type);
{
LONGEST high;
if (get_discrete_bounds (index_type, &low, &high) < 0)
len = 1;
else
len = high - low + 1;
}
i = 0;
annotate_array_section_begin (i, elttype);
while (i < len && things_printed < options->print_max)
{
struct value *v0, *v1;
int i0;
if (i != 0)
{
if (options->prettyformat_arrays)
{
fprintf_filtered (stream, ",\n");
print_spaces_filtered (2 + 2 * recurse, stream);
}
else
{
fprintf_filtered (stream, ", ");
}
}
wrap_here (n_spaces (2 + 2 * recurse));
maybe_print_array_index (index_type, i + low, stream, options);
i0 = i;
v0 = ada_value_primitive_packed_val (NULL, valaddr + offset,
(i0 * bitsize) / HOST_CHAR_BIT,
(i0 * bitsize) % HOST_CHAR_BIT,
bitsize, elttype);
while (1)
{
i += 1;
if (i >= len)
break;
v1 = ada_value_primitive_packed_val (NULL, valaddr + offset,
(i * bitsize) / HOST_CHAR_BIT,
(i * bitsize) % HOST_CHAR_BIT,
bitsize, elttype);
if (TYPE_LENGTH (check_typedef (value_type (v0)))
!= TYPE_LENGTH (check_typedef (value_type (v1))))
break;
if (!value_contents_eq (v0, value_embedded_offset (v0),
v1, value_embedded_offset (v1),
TYPE_LENGTH (check_typedef (value_type (v0)))))
break;
}
if (i - i0 > options->repeat_count_threshold)
{
struct value_print_options opts = *options;
opts.deref_ref = 0;
val_print (elttype,
value_embedded_offset (v0), 0, stream,
recurse + 1, v0, &opts, current_language);
annotate_elt_rep (i - i0);
fprintf_filtered (stream, _(" <repeats %u times>"), i - i0);
annotate_elt_rep_end ();
}
else
{
int j;
struct value_print_options opts = *options;
opts.deref_ref = 0;
for (j = i0; j < i; j += 1)
{
if (j > i0)
{
if (options->prettyformat_arrays)
{
fprintf_filtered (stream, ",\n");
print_spaces_filtered (2 + 2 * recurse, stream);
}
else
{
fprintf_filtered (stream, ", ");
}
wrap_here (n_spaces (2 + 2 * recurse));
maybe_print_array_index (index_type, j + low,
stream, options);
}
val_print (elttype,
value_embedded_offset (v0), 0, stream,
recurse + 1, v0, &opts, current_language);
annotate_elt ();
}
}
things_printed += i - i0;
}
annotate_array_section_end ();
if (i < len)
{
fprintf_filtered (stream, "...");
}
value_free_to_mark (mark);
}
static struct type *
printable_val_type (struct type *type, const gdb_byte *valaddr)
{
return ada_to_fixed_type (ada_aligned_type (type), valaddr, 0, NULL, 1);
}
/* Print the character C on STREAM as part of the contents of a literal
string whose delimiter is QUOTER. TYPE_LEN is the length in bytes
of the character. */
void
ada_emit_char (int c, struct type *type, struct ui_file *stream,
int quoter, int type_len)
{
/* If this character fits in the normal ASCII range, and is
a printable character, then print the character as if it was
an ASCII character, even if this is a wide character.
The UCHAR_MAX check is necessary because the isascii function
requires that its argument have a value of an unsigned char,
or EOF (EOF is obviously not printable). */
if (c <= UCHAR_MAX && isascii (c) && isprint (c))
{
if (c == quoter && c == '"')
fprintf_filtered (stream, "\"\"");
else
fprintf_filtered (stream, "%c", c);
}
else
fprintf_filtered (stream, "[\"%0*x\"]", type_len * 2, c);
}
/* Character #I of STRING, given that TYPE_LEN is the size in bytes
of a character. */
static int
char_at (const gdb_byte *string, int i, int type_len,
enum bfd_endian byte_order)
{
if (type_len == 1)
return string[i];
else
return (int) extract_unsigned_integer (string + type_len * i,
type_len, byte_order);
}
/* Print a floating-point value of type TYPE, pointed to in GDB by
VALADDR, on STREAM. Use Ada formatting conventions: there must be
a decimal point, and at least one digit before and after the
point. We use the GNAT format for NaNs and infinities. */
static void
ada_print_floating (const gdb_byte *valaddr, struct type *type,
struct ui_file *stream)
{
string_file tmp_stream;
print_floating (valaddr, type, &tmp_stream);
std::string &s = tmp_stream.string ();
size_t skip_count = 0;
/* Modify for Ada rules. */
size_t pos = s.find ("inf");
if (pos == std::string::npos)
pos = s.find ("Inf");
if (pos == std::string::npos)
pos = s.find ("INF");
if (pos != std::string::npos)
s.replace (pos, 3, "Inf");
if (pos == std::string::npos)
{
pos = s.find ("nan");
if (pos == std::string::npos)
pos = s.find ("NaN");
if (pos == std::string::npos)
pos = s.find ("Nan");
if (pos != std::string::npos)
{
s[pos] = s[pos + 2] = 'N';
if (s[0] == '-')
skip_count = 1;
}
}
if (pos == std::string::npos
&& s.find ('.') == std::string::npos)
{
pos = s.find ('e');
if (pos == std::string::npos)
fprintf_filtered (stream, "%s.0", s.c_str ());
else
fprintf_filtered (stream, "%.*s.0%s", (int) pos, s.c_str (), &s[pos]);
}
else
fprintf_filtered (stream, "%s", &s[skip_count]);
}
void
ada_printchar (int c, struct type *type, struct ui_file *stream)
{
fputs_filtered ("'", stream);
ada_emit_char (c, type, stream, '\'', TYPE_LENGTH (type));
fputs_filtered ("'", stream);
}
/* [From print_type_scalar in typeprint.c]. Print VAL on STREAM in a
form appropriate for TYPE, if non-NULL. If TYPE is NULL, print VAL
like a default signed integer. */
void
ada_print_scalar (struct type *type, LONGEST val, struct ui_file *stream)
{
unsigned int i;
unsigned len;
if (!type)
{
print_longest (stream, 'd', 0, val);
return;
}
type = ada_check_typedef (type);
switch (TYPE_CODE (type))
{
case TYPE_CODE_ENUM:
len = TYPE_NFIELDS (type);
for (i = 0; i < len; i++)
{
if (TYPE_FIELD_ENUMVAL (type, i) == val)
{
break;
}
}
if (i < len)
{
fputs_filtered (ada_enum_name (TYPE_FIELD_NAME (type, i)), stream);
}
else
{
print_longest (stream, 'd', 0, val);
}
break;
case TYPE_CODE_INT:
print_longest (stream, TYPE_UNSIGNED (type) ? 'u' : 'd', 0, val);
break;
case TYPE_CODE_CHAR:
LA_PRINT_CHAR (val, type, stream);
break;
case TYPE_CODE_BOOL:
fprintf_filtered (stream, val ? "true" : "false");
break;
case TYPE_CODE_RANGE:
ada_print_scalar (TYPE_TARGET_TYPE (type), val, stream);
return;
case TYPE_CODE_UNDEF:
case TYPE_CODE_PTR:
case TYPE_CODE_ARRAY:
case TYPE_CODE_STRUCT:
case TYPE_CODE_UNION:
case TYPE_CODE_FUNC:
case TYPE_CODE_FLT:
case TYPE_CODE_VOID:
case TYPE_CODE_SET:
case TYPE_CODE_STRING:
case TYPE_CODE_ERROR:
case TYPE_CODE_MEMBERPTR:
case TYPE_CODE_METHODPTR:
case TYPE_CODE_METHOD:
case TYPE_CODE_REF:
warning (_("internal error: unhandled type in ada_print_scalar"));
break;
default:
error (_("Invalid type code in symbol table."));
}
gdb_flush (stream);
}
/* Print the character string STRING, printing at most LENGTH characters.
Printing stops early if the number hits print_max; repeat counts
are printed as appropriate. Print ellipses at the end if we
had to stop before printing LENGTH characters, or if FORCE_ELLIPSES.
TYPE_LEN is the length (1 or 2) of the character type. */
static void
printstr (struct ui_file *stream, struct type *elttype, const gdb_byte *string,
unsigned int length, int force_ellipses, int type_len,
const struct value_print_options *options)
{
enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (elttype));
unsigned int i;
unsigned int things_printed = 0;
int in_quotes = 0;
int need_comma = 0;
if (length == 0)
{
fputs_filtered ("\"\"", stream);
return;
}
for (i = 0; i < length && things_printed < options->print_max; i += 1)
{
/* Position of the character we are examining
to see whether it is repeated. */
unsigned int rep1;
/* Number of repetitions we have detected so far. */
unsigned int reps;
QUIT;
if (need_comma)
{
fputs_filtered (", ", stream);
need_comma = 0;
}
rep1 = i + 1;
reps = 1;
while (rep1 < length
&& char_at (string, rep1, type_len, byte_order)
== char_at (string, i, type_len, byte_order))
{
rep1 += 1;
reps += 1;
}
if (reps > options->repeat_count_threshold)
{
if (in_quotes)
{
fputs_filtered ("\", ", stream);
in_quotes = 0;
}
fputs_filtered ("'", stream);
ada_emit_char (char_at (string, i, type_len, byte_order),
elttype, stream, '\'', type_len);
fputs_filtered ("'", stream);
fprintf_filtered (stream, _(" <repeats %u times>"), reps);
i = rep1 - 1;
things_printed += options->repeat_count_threshold;
need_comma = 1;
}
else
{
if (!in_quotes)
{
fputs_filtered ("\"", stream);
in_quotes = 1;
}
ada_emit_char (char_at (string, i, type_len, byte_order),
elttype, stream, '"', type_len);
things_printed += 1;
}
}
/* Terminate the quotes if necessary. */
if (in_quotes)
fputs_filtered ("\"", stream);
if (force_ellipses || i < length)
fputs_filtered ("...", stream);
}
void
ada_printstr (struct ui_file *stream, struct type *type,
const gdb_byte *string, unsigned int length,
const char *encoding, int force_ellipses,
const struct value_print_options *options)
{
printstr (stream, type, string, length, force_ellipses, TYPE_LENGTH (type),
options);
}
static int
print_variant_part (struct type *type, int field_num,
const gdb_byte *valaddr, int offset,
struct ui_file *stream, int recurse,
struct value *val,
const struct value_print_options *options,
int comma_needed,
struct type *outer_type, int outer_offset,
const struct language_defn *language)
{
struct type *var_type = TYPE_FIELD_TYPE (type, field_num);
int which = ada_which_variant_applies (var_type, outer_type,
valaddr + outer_offset);
if (which < 0)
return 0;
else
return print_field_values
(TYPE_FIELD_TYPE (var_type, which),
valaddr,
offset + TYPE_FIELD_BITPOS (type, field_num) / HOST_CHAR_BIT
+ TYPE_FIELD_BITPOS (var_type, which) / HOST_CHAR_BIT,
stream, recurse, val, options,
comma_needed, outer_type, outer_offset, language);
}
/* Print out fields of value at VALADDR + OFFSET having structure type TYPE.
TYPE, VALADDR, OFFSET, STREAM, RECURSE, and OPTIONS have the same
meanings as in ada_print_value and ada_val_print.
OUTER_TYPE and OUTER_OFFSET give type and address of enclosing
record (used to get discriminant values when printing variant
parts).
COMMA_NEEDED is 1 if fields have been printed at the current recursion
level, so that a comma is needed before any field printed by this
call.
Returns 1 if COMMA_NEEDED or any fields were printed. */
static int
print_field_values (struct type *type, const gdb_byte *valaddr,
int offset, struct ui_file *stream, int recurse,
struct value *val,
const struct value_print_options *options,
int comma_needed,
struct type *outer_type, int outer_offset,
const struct language_defn *language)
{
int i, len;
len = TYPE_NFIELDS (type);
for (i = 0; i < len; i += 1)
{
if (ada_is_ignored_field (type, i))
continue;
if (ada_is_wrapper_field (type, i))
{
comma_needed =
print_field_values (TYPE_FIELD_TYPE (type, i),
valaddr,
(offset
+ TYPE_FIELD_BITPOS (type, i) / HOST_CHAR_BIT),
stream, recurse, val, options,
comma_needed, type, offset, language);
continue;
}
else if (ada_is_variant_part (type, i))
{
comma_needed =
print_variant_part (type, i, valaddr,
offset, stream, recurse, val,
options, comma_needed,
outer_type, outer_offset, language);
continue;
}
if (comma_needed)
fprintf_filtered (stream, ", ");
comma_needed = 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));
fprintf_filtered (stream, "%.*s",
ada_name_prefix_len (TYPE_FIELD_NAME (type, i)),
TYPE_FIELD_NAME (type, i));
annotate_field_name_end ();
fputs_filtered (" => ", stream);
annotate_field_value ();
if (TYPE_FIELD_PACKED (type, i))
{
/* Bitfields require special handling, especially due to byte
order problems. */
if (HAVE_CPLUS_STRUCT (type) && TYPE_FIELD_IGNORE (type, i))
{
fputs_filtered (_("<optimized out or zero length>"), stream);
}
else
{
struct value *v;
int bit_pos = TYPE_FIELD_BITPOS (type, i);
int bit_size = TYPE_FIELD_BITSIZE (type, i);
struct value_print_options opts;
adjust_type_signedness (TYPE_FIELD_TYPE (type, i));
v = ada_value_primitive_packed_val
(NULL, valaddr,
offset + bit_pos / HOST_CHAR_BIT,
bit_pos % HOST_CHAR_BIT,
bit_size, TYPE_FIELD_TYPE (type, i));
opts = *options;
opts.deref_ref = 0;
val_print (TYPE_FIELD_TYPE (type, i),
value_embedded_offset (v), 0,
stream, recurse + 1, v,
&opts, language);
}
}
else
{
struct value_print_options opts = *options;
opts.deref_ref = 0;
val_print (TYPE_FIELD_TYPE (type, i),
(offset + TYPE_FIELD_BITPOS (type, i) / HOST_CHAR_BIT),
0, stream, recurse + 1, val, &opts, language);
}
annotate_field_end ();
}
return comma_needed;
}
/* Implement Ada val_print'ing for the case where TYPE is
a TYPE_CODE_ARRAY of characters. */
static void
ada_val_print_string (struct type *type, const gdb_byte *valaddr,
int offset, int offset_aligned, CORE_ADDR address,
struct ui_file *stream, int recurse,
struct value *original_value,
const struct value_print_options *options)
{
enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
struct type *elttype = TYPE_TARGET_TYPE (type);
unsigned int eltlen;
unsigned int len;
/* We know that ELTTYPE cannot possibly be null, because we assume
that we're called only when TYPE is a string-like type.
Similarly, the size of ELTTYPE should also be non-null, since
it's a character-like type. */
gdb_assert (elttype != NULL);
gdb_assert (TYPE_LENGTH (elttype) != 0);
eltlen = TYPE_LENGTH (elttype);
len = TYPE_LENGTH (type) / eltlen;
if (options->prettyformat_arrays)
print_spaces_filtered (2 + 2 * recurse, stream);
/* If requested, look for the first null char and only print
elements up to it. */
if (options->stop_print_at_null)
{
int temp_len;
/* Look for a NULL char. */
for (temp_len = 0;
(temp_len < len
&& temp_len < options->print_max
&& char_at (valaddr + offset_aligned,
temp_len, eltlen, byte_order) != 0);
temp_len += 1);
len = temp_len;
}
printstr (stream, elttype, valaddr + offset_aligned, len, 0,
eltlen, options);
}
/* Implement Ada val_print-ing for GNAT arrays (Eg. fat pointers,
thin pointers, etc). */
static void
ada_val_print_gnat_array (struct type *type, const gdb_byte *valaddr,
int offset, CORE_ADDR address,
struct ui_file *stream, int recurse,
struct value *original_value,
const struct value_print_options *options,
const struct language_defn *language)
{
struct value *mark = value_mark ();
struct value *val;
val = value_from_contents_and_address (type, valaddr + offset, address);
/* If this is a reference, coerce it now. This helps taking care
of the case where ADDRESS is meaningless because original_value
was not an lval. */
val = coerce_ref (val);
if (TYPE_CODE (type) == TYPE_CODE_TYPEDEF) /* array access type. */
val = ada_coerce_to_simple_array_ptr (val);
else
val = ada_coerce_to_simple_array (val);
if (val == NULL)
{
gdb_assert (TYPE_CODE (type) == TYPE_CODE_TYPEDEF);
fprintf_filtered (stream, "0x0");
}
else
val_print (value_type (val),
value_embedded_offset (val), value_address (val),
stream, recurse, val, options, language);
value_free_to_mark (mark);
}
/* Implement Ada val_print'ing for the case where TYPE is
a TYPE_CODE_PTR. */
static void
ada_val_print_ptr (struct type *type, const gdb_byte *valaddr,
int offset, int offset_aligned, CORE_ADDR address,
struct ui_file *stream, int recurse,
struct value *original_value,
const struct value_print_options *options,
const struct language_defn *language)
{
val_print (type, offset, address, stream, recurse,
original_value, options, language_def (language_c));
if (ada_is_tag_type (type))
{
struct value *val =
value_from_contents_and_address (type,
valaddr + offset_aligned,
address + offset_aligned);
const char *name = ada_tag_name (val);
if (name != NULL)
fprintf_filtered (stream, " (%s)", name);
}
}
/* Implement Ada val_print'ing for the case where TYPE is
a TYPE_CODE_INT or TYPE_CODE_RANGE. */
static void
ada_val_print_num (struct type *type, const gdb_byte *valaddr,
int offset, int offset_aligned, CORE_ADDR address,
struct ui_file *stream, int recurse,
struct value *original_value,
const struct value_print_options *options,
const struct language_defn *language)
{
if (ada_is_fixed_point_type (type))
{
struct value *scale = ada_scaling_factor (type);
struct value *v = value_from_contents (type, valaddr + offset_aligned);
v = value_cast (value_type (scale), v);
v = value_binop (v, scale, BINOP_MUL);
const char *fmt = TYPE_LENGTH (type) < 4 ? "%.11g" : "%.17g";
std::string str
= target_float_to_string (value_contents (v), value_type (v), fmt);
fputs_filtered (str.c_str (), stream);
return;
}
else if (TYPE_CODE (type) == TYPE_CODE_RANGE)
{
struct type *target_type = TYPE_TARGET_TYPE (type);
if (TYPE_LENGTH (type) != TYPE_LENGTH (target_type))
{
/* Obscure case of range type that has different length from
its base type. Perform a conversion, or we will get a
nonsense value. Actually, we could use the same
code regardless of lengths; I'm just avoiding a cast. */
struct value *v1
= value_from_contents_and_address (type, valaddr + offset, 0);
struct value *v = value_cast (target_type, v1);
val_print (target_type,
value_embedded_offset (v), 0, stream,
recurse + 1, v, options, language);
}
else
val_print (TYPE_TARGET_TYPE (type), offset,
address, stream, recurse, original_value,
options, language);
return;
}
else
{
int format = (options->format ? options->format
: options->output_format);
if (format)
{
struct value_print_options opts = *options;
opts.format = format;
val_print_scalar_formatted (type, offset_aligned,
original_value, &opts, 0, stream);
}
else if (ada_is_system_address_type (type))
{
/* FIXME: We want to print System.Address variables using
the same format as for any access type. But for some
reason GNAT encodes the System.Address type as an int,
so we have to work-around this deficiency by handling
System.Address values as a special case. */
struct gdbarch *gdbarch = get_type_arch (type);
struct type *ptr_type = builtin_type (gdbarch)->builtin_data_ptr;
CORE_ADDR addr = extract_typed_address (valaddr + offset_aligned,
ptr_type);
fprintf_filtered (stream, "(");
type_print (type, "", stream, -1);
fprintf_filtered (stream, ") ");
fputs_filtered (paddress (gdbarch, addr), stream);
}
else
{
val_print_scalar_formatted (type, offset_aligned,
original_value, options, 0, stream);
if (ada_is_character_type (type))
{
LONGEST c;
fputs_filtered (" ", stream);
c = unpack_long (type, valaddr + offset_aligned);
ada_printchar (c, type, stream);
}
}
return;
}
}
/* Implement Ada val_print'ing for the case where TYPE is
a TYPE_CODE_ENUM. */
static void
ada_val_print_enum (struct type *type, const gdb_byte *valaddr,
int offset, int offset_aligned, CORE_ADDR address,
struct ui_file *stream, int recurse,
struct value *original_value,
const struct value_print_options *options,
const struct language_defn *language)
{
int i;
unsigned int len;
LONGEST val;
if (options->format)
{
val_print_scalar_formatted (type, offset_aligned,
original_value, options, 0, stream);
return;
}
len = TYPE_NFIELDS (type);
val = unpack_long (type, valaddr + offset_aligned);
for (i = 0; i < len; i++)
{
QUIT;
if (val == TYPE_FIELD_ENUMVAL (type, i))
break;
}
if (i < len)
{
const char *name = ada_enum_name (TYPE_FIELD_NAME (type, i));
if (name[0] == '\'')
fprintf_filtered (stream, "%ld %s", (long) val, name);
else
fputs_filtered (name, stream);
}
else
print_longest (stream, 'd', 0, val);
}
/* Implement Ada val_print'ing for the case where TYPE is
a TYPE_CODE_FLT. */
static void
ada_val_print_flt (struct type *type, const gdb_byte *valaddr,
int offset, int offset_aligned, CORE_ADDR address,
struct ui_file *stream, int recurse,
struct value *original_value,
const struct value_print_options *options,
const struct language_defn *language)
{
if (options->format)
{
val_print (type, offset, address, stream, recurse,
original_value, options, language_def (language_c));
return;
}
ada_print_floating (valaddr + offset, type, stream);
}
/* Implement Ada val_print'ing for the case where TYPE is
a TYPE_CODE_STRUCT or TYPE_CODE_UNION. */
static void
ada_val_print_struct_union
(struct type *type, const gdb_byte *valaddr, int offset,
int offset_aligned, CORE_ADDR address, struct ui_file *stream,
int recurse, struct value *original_value,
const struct value_print_options *options,
const struct language_defn *language)
{
if (ada_is_bogus_array_descriptor (type))
{
fprintf_filtered (stream, "(...?)");
return;
}
fprintf_filtered (stream, "(");
if (print_field_values (type, valaddr, offset_aligned,
stream, recurse, original_value, options,
0, type, offset_aligned, language) != 0
&& options->prettyformat)
{
fprintf_filtered (stream, "\n");
print_spaces_filtered (2 * recurse, stream);
}
fprintf_filtered (stream, ")");
}
/* Implement Ada val_print'ing for the case where TYPE is
a TYPE_CODE_ARRAY. */
static void
ada_val_print_array (struct type *type, const gdb_byte *valaddr,
int offset, int offset_aligned, CORE_ADDR address,
struct ui_file *stream, int recurse,
struct value *original_value,
const struct value_print_options *options)
{
/* For an array of characters, print with string syntax. */
if (ada_is_string_type (type)
&& (options->format == 0 || options->format == 's'))
{
ada_val_print_string (type, valaddr, offset, offset_aligned,
address, stream, recurse, original_value,
options);
return;
}
fprintf_filtered (stream, "(");
print_optional_low_bound (stream, type, options);
if (TYPE_FIELD_BITSIZE (type, 0) > 0)
val_print_packed_array_elements (type, valaddr, offset_aligned,
0, stream, recurse,
original_value, options);
else
val_print_array_elements (type, offset_aligned, address,
stream, recurse, original_value,
options, 0);
fprintf_filtered (stream, ")");
}
/* Implement Ada val_print'ing for the case where TYPE is
a TYPE_CODE_REF. */
static void
ada_val_print_ref (struct type *type, const gdb_byte *valaddr,
int offset, int offset_aligned, CORE_ADDR address,
struct ui_file *stream, int recurse,
struct value *original_value,
const struct value_print_options *options,
const struct language_defn *language)
{
/* For references, the debugger is expected to print the value as
an address if DEREF_REF is null. But printing an address in place
of the object value would be confusing to an Ada programmer.
So, for Ada values, we print the actual dereferenced value
regardless. */
struct type *elttype = check_typedef (TYPE_TARGET_TYPE (type));
struct value *deref_val;
CORE_ADDR deref_val_int;
if (TYPE_CODE (elttype) == TYPE_CODE_UNDEF)
{
fputs_filtered ("<ref to undefined type>", stream);
return;
}
deref_val = coerce_ref_if_computed (original_value);
if (deref_val)
{
if (ada_is_tagged_type (value_type (deref_val), 1))
deref_val = ada_tag_value_at_base_address (deref_val);
common_val_print (deref_val, stream, recurse + 1, options,
language);
return;
}
deref_val_int = unpack_pointer (type, valaddr + offset_aligned);
if (deref_val_int == 0)
{
fputs_filtered ("(null)", stream);
return;
}
deref_val
= ada_value_ind (value_from_pointer (lookup_pointer_type (elttype),
deref_val_int));
if (ada_is_tagged_type (value_type (deref_val), 1))
deref_val = ada_tag_value_at_base_address (deref_val);
/* Make sure that the object does not have an unreasonable size
before trying to print it. This can happen for instance with
references to dynamic objects whose contents is uninitialized
(Eg: an array whose bounds are not set yet). */
ada_ensure_varsize_limit (value_type (deref_val));
if (value_lazy (deref_val))
value_fetch_lazy (deref_val);
val_print (value_type (deref_val),
value_embedded_offset (deref_val),
value_address (deref_val), stream, recurse + 1,
deref_val, options, language);
}
/* See the comment on ada_val_print. This function differs in that it
does not catch evaluation errors (leaving that to ada_val_print). */
static void
ada_val_print_1 (struct type *type,
int offset, CORE_ADDR address,
struct ui_file *stream, int recurse,
struct value *original_value,
const struct value_print_options *options,
const struct language_defn *language)
{
int offset_aligned;
const gdb_byte *valaddr = value_contents_for_printing (original_value);
type = ada_check_typedef (type);
if (ada_is_array_descriptor_type (type)
|| (ada_is_constrained_packed_array_type (type)
&& TYPE_CODE (type) != TYPE_CODE_PTR))
{
ada_val_print_gnat_array (type, valaddr, offset, address,
stream, recurse, original_value,
options, language);
return;
}
offset_aligned = offset + ada_aligned_value_addr (type, valaddr) - valaddr;
type = printable_val_type (type, valaddr + offset_aligned);
type = resolve_dynamic_type (type, valaddr + offset_aligned,
address + offset_aligned);
switch (TYPE_CODE (type))
{
default:
val_print (type, offset, address, stream, recurse,
original_value, options, language_def (language_c));
break;
case TYPE_CODE_PTR:
ada_val_print_ptr (type, valaddr, offset, offset_aligned,
address, stream, recurse, original_value,
options, language);
break;
case TYPE_CODE_INT:
case TYPE_CODE_RANGE:
ada_val_print_num (type, valaddr, offset, offset_aligned,
address, stream, recurse, original_value,
options, language);
break;
case TYPE_CODE_ENUM:
ada_val_print_enum (type, valaddr, offset, offset_aligned,
address, stream, recurse, original_value,
options, language);
break;
case TYPE_CODE_FLT:
ada_val_print_flt (type, valaddr, offset, offset_aligned,
address, stream, recurse, original_value,
options, language);
break;
case TYPE_CODE_UNION:
case TYPE_CODE_STRUCT:
ada_val_print_struct_union (type, valaddr, offset, offset_aligned,
address, stream, recurse,
original_value, options, language);
break;
case TYPE_CODE_ARRAY:
ada_val_print_array (type, valaddr, offset, offset_aligned,
address, stream, recurse, original_value,
options);
return;
case TYPE_CODE_REF:
ada_val_print_ref (type, valaddr, offset, offset_aligned,
address, stream, recurse, original_value,
options, language);
break;
}
}
/* See val_print for a description of the various parameters of this
function; they are identical. */
void
ada_val_print (struct type *type,
int embedded_offset, CORE_ADDR address,
struct ui_file *stream, int recurse,
struct value *val,
const struct value_print_options *options)
{
TRY
{
ada_val_print_1 (type, embedded_offset, address,
stream, recurse, val, options,
current_language);
}
CATCH (except, RETURN_MASK_ERROR)
{
fprintf_filtered (stream, _("<error reading variable: %s>"),
except.message);
}
END_CATCH
}
void
ada_value_print (struct value *val0, struct ui_file *stream,
const struct value_print_options *options)
{
struct value *val = ada_to_fixed_value (val0);
CORE_ADDR address = value_address (val);
struct type *type = ada_check_typedef (value_enclosing_type (val));
struct value_print_options opts;
/* If it is a pointer, indicate what it points to. */
if (TYPE_CODE (type) == TYPE_CODE_PTR)
{
/* Hack: don't print (char *) for char strings. Their
type is indicated by the quoted string anyway. */
if (TYPE_LENGTH (TYPE_TARGET_TYPE (type)) != sizeof (char)
|| TYPE_CODE (TYPE_TARGET_TYPE (type)) != TYPE_CODE_INT
|| TYPE_UNSIGNED (TYPE_TARGET_TYPE (type)))
{
fprintf_filtered (stream, "(");
type_print (type, "", stream, -1);
fprintf_filtered (stream, ") ");
}
}
else if (ada_is_array_descriptor_type (type))
{
/* We do not print the type description unless TYPE is an array
access type (this is encoded by the compiler as a typedef to
a fat pointer - hence the check against TYPE_CODE_TYPEDEF). */
if (TYPE_CODE (type) == TYPE_CODE_TYPEDEF)
{
fprintf_filtered (stream, "(");
type_print (type, "", stream, -1);
fprintf_filtered (stream, ") ");
}
}
else if (ada_is_bogus_array_descriptor (type))
{
fprintf_filtered (stream, "(");
type_print (type, "", stream, -1);
fprintf_filtered (stream, ") (...?)");
return;
}
opts = *options;
opts.deref_ref = 1;
val_print (type,
value_embedded_offset (val), address,
stream, 0, val, &opts, current_language);
}