binutils-gdb/gdb/valprint.h
Andrew Burgess 76b58849c5 GDB: Add a character string limiting option
This commit splits the `set/show print elements' option into two.  We
retain `set/show print elements' for controlling how many elements of an
array we print, but a new `set/show print characters' setting is added
which is used for controlling how many characters of a string are
printed.

The motivation behind this change is to allow users a finer level of
control over how data is printed, reflecting that, although strings can
be thought of as arrays of characters, users often want to treat these
two things differently.

For compatibility reasons by default the `set/show print characters'
option is set to `elements', which makes the limit for character strings
follow the setting of the `set/show print elements' option, as it used
to.  Using `set print characters' with any other value makes the limit
independent from the `set/show print elements' setting, however it can
be restored to the default with the `set print characters elements'
command at any time.

A corresponding `-characters' option for the `print' command is added,
with the same semantics, i.e. one can use `elements' to make a given
`print' invocation follow the limit of elements, be it set with the
`-elements' option also given with the same invocation or taken from the
`set/show print elements' setting, for characters as well regardless of
the current setting of the `set/show print characters' option.

The GDB changes are all pretty straightforward, just changing references
to the old 'print_max' to use a new `get_print_max_chars' helper which
figures out which of the two of `print_max' and `print_max_chars' values
to use.

Likewise, the documentation is just updated to reference the new setting
where appropriate.

To make people's life easier the message shown by `show print elements'
now indicates if the setting also applies to character strings:

(gdb) set print characters elements
(gdb) show print elements
Limit on string chars or array elements to print is 200.
(gdb) set print characters unlimited
(gdb) show print elements
Limit on array elements to print is 200.
(gdb)

and the help text shows the dependency as well:

(gdb) help set print elements
Set limit on array elements to print.
"unlimited" causes there to be no limit.
This setting also applies to string chars when "print characters"
is set to "elements".
(gdb)

In the testsuite there are two minor updates, one to add `-characters'
to the list of completions now shown for the `print' command, and a bare
minimum pair of checks for the right handling of `set print characters'
and `show print characters', copied from the corresponding checks for
`set print elements' and `show print elements' respectively.

Co-Authored-By: Maciej W. Rozycki <macro@embecosm.com>
Approved-By: Simon Marchi <simon.marchi@efficios.com>
2023-01-19 21:15:56 +00:00

330 lines
11 KiB
C++

/* Declarations for value printing routines for GDB, the GNU debugger.
Copyright (C) 1986-2023 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/>. */
#ifndef VALPRINT_H
#define VALPRINT_H
#include "cli/cli-option.h"
/* This is used to pass formatting options to various value-printing
functions. */
struct value_print_options
{
/* Pretty-formatting control. */
enum val_prettyformat prettyformat;
/* Controls pretty formatting of arrays. */
bool prettyformat_arrays;
/* Controls pretty formatting of structures. */
bool prettyformat_structs;
/* Controls printing of virtual tables. */
bool vtblprint;
/* Controls printing of nested unions. */
bool unionprint;
/* Controls printing of addresses. */
bool addressprint;
/* Controls printing of nibbles. */
bool nibblesprint;
/* Controls looking up an object's derived type using what we find
in its vtables. */
bool objectprint;
/* Maximum number of elements to print for vector contents, or UINT_MAX
for no limit. Note that "set print elements 0" stores UINT_MAX in
print_max, which displays in a show command as "unlimited". */
unsigned int print_max;
/* Maximum number of string chars to print for a string pointer value,
zero if to follow the value of print_max, or UINT_MAX for no limit. */
unsigned int print_max_chars;
/* Print repeat counts if there are more than this many repetitions
of an element in an array. */
unsigned int repeat_count_threshold;
/* The global output format letter. */
int output_format;
/* The current format letter. This is set locally for a given call,
e.g. when the user passes a format to "print". */
int format;
/* Print memory tag violations for pointers. */
bool memory_tag_violations;
/* Stop printing at null character? */
bool stop_print_at_null;
/* True if we should print the index of each element when printing
an array. */
bool print_array_indexes;
/* If true, then dereference references, otherwise just print
them like pointers. */
bool deref_ref;
/* If true, print static fields. */
bool static_field_print;
/* If true, print static fields for Pascal. FIXME: C++ has a
flag, why not share with Pascal too? */
bool pascal_static_field_print;
/* If true, don't do Python pretty-printing. */
bool raw;
/* If true, print the value in "summary" form.
If raw and summary are both true, don't print non-scalar values
("..." is printed instead). */
bool summary;
/* If true, when printing a pointer, print the symbol to which it
points, if any. */
bool symbol_print;
/* Maximum print depth when printing nested aggregates. */
int max_depth;
};
/* The value to use for `print_max_chars' to follow `print_max'. */
#define PRINT_MAX_CHARS_ELEMENTS 0
/* The value to use for `print_max_chars' for no limit. */
#define PRINT_MAX_CHARS_UNLIMITED UINT_MAX
/* Return the character count limit for printing strings. */
static inline unsigned int
get_print_max_chars (const struct value_print_options *options)
{
return (options->print_max_chars != PRINT_MAX_CHARS_ELEMENTS
? options->print_max_chars : options->print_max);
}
/* Create an option_def_group for the value_print options, with OPTS
as context. */
extern gdb::option::option_def_group make_value_print_options_def_group
(value_print_options *opts);
/* The global print options set by the user. In general this should
not be directly accessed, except by set/show commands. Ordinary
code should call get_user_print_options instead. */
extern struct value_print_options user_print_options;
/* Initialize *OPTS to be a copy of the user print options. */
extern void get_user_print_options (struct value_print_options *opts);
/* Initialize *OPTS to be a copy of the user print options, but with
pretty-formatting disabled. */
extern void get_no_prettyformat_print_options (struct value_print_options *);
/* Initialize *OPTS to be a copy of the user print options, but using
FORMAT as the formatting option. */
extern void get_formatted_print_options (struct value_print_options *opts,
char format);
extern void maybe_print_array_index (struct type *index_type, LONGEST index,
struct ui_file *stream,
const struct value_print_options *);
/* Print elements of an array. */
extern void value_print_array_elements (struct value *, struct ui_file *, int,
const struct value_print_options *,
unsigned int);
/* Print a scalar according to OPTIONS and SIZE on STREAM. Format 'i'
is not supported at this level.
This is how the elements of an array or structure are printed
with a format. */
extern void value_print_scalar_formatted
(struct value *val, const struct value_print_options *options,
int size, struct ui_file *stream);
extern void print_binary_chars (struct ui_file *, const gdb_byte *,
unsigned int, enum bfd_endian, bool,
const struct value_print_options *options);
extern void print_octal_chars (struct ui_file *, const gdb_byte *,
unsigned int, enum bfd_endian);
extern void print_decimal_chars (struct ui_file *, const gdb_byte *,
unsigned int, bool, enum bfd_endian);
extern void print_hex_chars (struct ui_file *, const gdb_byte *,
unsigned int, enum bfd_endian, bool);
extern void print_function_pointer_address (const struct value_print_options *options,
struct gdbarch *gdbarch,
CORE_ADDR address,
struct ui_file *stream);
/* Helper function to check the validity of some bits of a value.
If TYPE represents some aggregate type (e.g., a structure), return 1.
Otherwise, any of the bytes starting at OFFSET and extending for
TYPE->length () bytes are invalid, print a message to STREAM and
return 0. The checking is done using FUNCS.
Otherwise, return 1. */
extern int valprint_check_validity (struct ui_file *stream, struct type *type,
LONGEST embedded_offset,
const struct value *val);
extern void val_print_optimized_out (const struct value *val,
struct ui_file *stream);
/* Prints "<not saved>" to STREAM. */
extern void val_print_not_saved (struct ui_file *stream);
extern void val_print_unavailable (struct ui_file *stream);
extern void val_print_invalid_address (struct ui_file *stream);
/* An instance of this is passed to generic_val_print and describes
some language-specific ways to print things. */
struct generic_val_print_decorations
{
/* Printing complex numbers: what to print before, between the
elements, and after. */
const char *complex_prefix;
const char *complex_infix;
const char *complex_suffix;
/* Boolean true and false. */
const char *true_name;
const char *false_name;
/* What to print when we see TYPE_CODE_VOID. */
const char *void_name;
/* Array start and end strings. */
const char *array_start;
const char *array_end;
};
/* Print a value in a generic way. VAL is the value, STREAM is where
to print it, RECURSE is the recursion depth, OPTIONS describe how
the printing should be done, and D is the language-specific
decorations object. Note that structs and unions cannot be printed
by this function. */
extern void generic_value_print (struct value *val, struct ui_file *stream,
int recurse,
const struct value_print_options *options,
const struct generic_val_print_decorations *d);
extern void generic_emit_char (int c, struct type *type, struct ui_file *stream,
int quoter, const char *encoding);
extern void generic_printstr (struct ui_file *stream, struct type *type,
const gdb_byte *string, unsigned int length,
const char *encoding, int force_ellipses,
int quote_char, int c_style_terminator,
const struct value_print_options *options);
/* Run the "output" command. ARGS and FROM_TTY are the usual
arguments passed to all command implementations, except ARGS is
const. */
extern void output_command (const char *args, int from_tty);
extern int val_print_scalar_type_p (struct type *type);
struct format_data
{
int count;
char format;
char size;
bool print_tags;
/* True if the value should be printed raw -- that is, bypassing
python-based formatters. */
unsigned char raw;
};
extern void print_command_parse_format (const char **expp, const char *cmdname,
value_print_options *opts);
/* Print VAL to console according to OPTS, including recording it to
the history. */
extern void print_value (value *val, const value_print_options &opts);
/* Completer for the "print", "call", and "compile print"
commands. */
extern void print_command_completer (struct cmd_list_element *ignore,
completion_tracker &tracker,
const char *text, const char *word);
/* Given an address ADDR return all the elements needed to print the
address in a symbolic form. NAME can be mangled or not depending
on DO_DEMANGLE (and also on the asm_demangle global variable,
manipulated via ''set print asm-demangle''). When
PREFER_SYM_OVER_MINSYM is true, names (and offsets) from minimal
symbols won't be used except in instances where no symbol was
found; otherwise, a minsym might be used in some instances (mostly
involving function with non-contiguous address ranges). Return
0 in case of success, when all the info in the OUT parameters is
valid. Return 1 otherwise. */
extern int build_address_symbolic (struct gdbarch *,
CORE_ADDR addr,
bool do_demangle,
bool prefer_sym_over_minsym,
std::string *name,
int *offset,
std::string *filename,
int *line,
int *unmapped);
/* Check to see if RECURSE is greater than or equal to the allowed
printing max-depth (see 'set print max-depth'). If it is then print an
ellipsis expression to STREAM and return true, otherwise return false.
LANGUAGE determines what type of ellipsis expression is printed. */
extern bool val_print_check_max_depth (struct ui_file *stream, int recurse,
const struct value_print_options *opts,
const struct language_defn *language);
/* Like common_val_print, but call value_check_printable first. */
extern void common_val_print_checked
(struct value *val,
struct ui_file *stream, int recurse,
const struct value_print_options *options,
const struct language_defn *language);
#endif