binutils-gdb/gdb/cli/cli-utils.c
Pedro Alves 9d0faba9f5 Introduce generic command options framework
This commit adds a generic command options framework, that makes it
easy enough to add '-'-style options to commands in a uniform way,
instead of each command implementing option parsing in its own way.

Options are defined in arrays of option_def objects (for option
definition), and the same options definitions are used for supporting
TAB completion, and also for generating the relevant help fragment of
the "help" command.  See the gdb::options::build_help function, which
returns a string with the result of replacing %OPTIONS% in a template
string with an auto-generated "help" string fragment for all the
passed-in options.

Since most options in GDB are in the form of "-OPT", with a single
dash, this is the format that the framework supports.

I like to think of gdb's "-OPT" as the equivalent to getopt's long
options format ("--OPT"), and gdb's "/" as the equivalent to getopt's
short options format.  getopt's short options format allows mixing
several one-character options, like "ls -als", kind of similar to
gdb's "x /FMT" and "disassemble /MOD", etc.  While with gdb's "-"
options, the option is expected to have a full name, and to be
abbreviatable.  E.g., "watch -location", "break -function main", etc.

This patch only deals with "-" options.  The above comment serves more
to disclose why I don't think we should support mixing several
unrelated options in a single "-" option invocation, like "thread
apply -qcs" instead of "thread apply -q -c -s".

The following patches will add uses of the infrastructure to several
key commands.  Most notably, "print", "compile print", "backtrace",
"frame apply" and "thread apply".  I tried to add options to several
commands in order to make sure the framework didn't leave that many
open holes open.

Options use the same type as set commands -- enum var_types.  So
boolean options are var_boolean, enum options are var_enum, etc.  The
idea is to share code between settings commands and command options.
The "print" options will be based on the "set print" commands, and
their names will be the same.  Actually, their definitions will be the
same too.  There is a function to create "set/show" commands from an
array for option definitions:

 /* Install set/show commands for options defined in OPTIONS.  DATA is
    a pointer to the structure that holds the data associated with the
    OPTIONS array.  */
 extern void add_setshow_cmds_for_options (command_class cmd_class, void *data,
					   gdb::array_view<const option_def> options,
					   struct cmd_list_element **set_list,
					   struct cmd_list_element **show_list);

That will be used by several following patches.

Other features:

 - You can use the "--" delimiter to explicitly indicate end of
   options.  Several existing commands use this token sequence for
   this effect already, so this just standardizes it.

 - You can shorten option names, as long as unambiguous.  Currently,
   some commands allow this (e.g., break -function), while others do
   not (thread apply all -ascending).  As GDB allows abbreviating
   command names and other things, it feels more GDB-ish to allow
   abbreviating option names too, to me.

 - For boolean options, 0/1 stands for off/on, just like with boolean
   "set" commands.

 - For boolean options, "true" is implied, just like with boolean "set
   commands.

These are the option types supported, with a few examples:

 - boolean options (var_boolean).  The option's argument is optional.

   (gdb) print -pretty on -- *obj
   (gdb) print -pretty off -- *obj
   (gdb) print -p -- *obj
   (gdb) print -p 0 -- *obj

 - flag options (like var_boolean, but no option argument (on/off))

   (gdb) thread apply all -s COMMAND

 - enum options  (var_enum)

   (gdb) bt -entry-values compact
   (gdb) bt -e c

 - uinteger options (var_uinteger)

   (gdb) print -elements 100 -- *obj
   (gdb) print -e 100 -- *obj
   (gdb) print -elements unlimited -- *obj
   (gdb) print -e u -- *obj

 - zuinteger-unlimited options (var_zuinteger_unlimited)

   (gdb) print -max-depth 100 -- obj
   (gdb) print -max-depth -1 -- obj
   (gdb) print -max-depth unlimited -- obj

Other var_types could be supported, of course.  These were just the
types that I needed for the commands that I ported over, in the
following patches.

It was interesting (and unfortunate) to find that we need at least 3
different modes to cover the existing commands:

- Commands that require ending options with "--" if you specify any
  option: "print" and "compile print".

- Commands that do not want to require "--", and want to error out if
  you specify an unknown option (i.e., an unknown argument that starts
  with '-'): "compile code" / "compile file".

- Commands that do not want to require "--", and want to process
  unknown options themselves: "bt", because of "bt -COUNT",
  "thread/frame apply", because "-" is a valid command.

The different behavior is encoded in the process_options_mode enum,
passed to process_options/complete_options.

For testing, this patch adds one representative maintenance command
for each of the process_options_mode values, that are used by the
testsuite to exercise the options framework:

 (gdb) maint test-options require-delimiter
 (gdb) maint test-options unknown-is-error
 (gdb) maint test-options unknown-is-operand

and adds another command to help with TAB-completion testing:

 (gdb) maint show test-options-completion-result

See their description at the top of the maint-test-options.c file.

Docs/NEWS are in a patch later in the series.

gdb/ChangeLog:
2019-06-13  Pedro Alves  <palves@redhat.com>

	* Makefile.in (SUBDIR_CLI_SRCS): Add cli/cli-option.c.
	(COMMON_SFILES): Add maint-test-settings.c.
	* cli/cli-decode.c (boolean_enums): New global, factored out from
	...
	(add_setshow_boolean_cmd): ... here.
	* cli/cli-decode.h (boolean_enums): Declare.
	* cli/cli-option.c: New file.
	* cli/cli-option.h: New file.
	* cli/cli-setshow.c (parse_cli_boolean_value(const char **)): New,
	factored out from ...
	(parse_cli_boolean_value(const char *)): ... this.
	(is_unlimited_literal): Change parameter type to pointer to
	pointer.  Adjust and advance ARG pointer.
	(parse_cli_var_uinteger, parse_cli_var_zuinteger_unlimited)
	(parse_cli_var_enum): New, factored out from ...
	(do_set_command): ... this.  Adjust.
	* cli/cli-setshow.h (parse_cli_boolean_value)
	(parse_cli_var_uinteger, parse_cli_var_zuinteger_unlimited)
	(parse_cli_var_enum): Declare.
	* cli/cli-utils.c: Include "cli/cli-option.h".
	(get_ulongest): New.
	* cli/cli-utils.h (get_ulongest): Declare.
	(check_for_argument): New overloads.
	* maint-test-options.c: New file.

gdb/testsuite/ChangeLog:
2019-06-13  Pedro Alves  <palves@redhat.com>

	* gdb.base/options.c: New file.
	* gdb.base/options.exp: New file.
2019-06-13 00:18:12 +01:00

580 lines
13 KiB
C

/* CLI utilities.
Copyright (C) 2011-2019 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 "cli/cli-utils.h"
#include "value.h"
#include <ctype.h>
static std::string extract_arg_maybe_quoted (const char **arg);
/* See documentation in cli-utils.h. */
ULONGEST
get_ulongest (const char **pp, int trailer)
{
LONGEST retval = 0; /* default */
const char *p = *pp;
if (*p == '$')
{
value *val = value_from_history_ref (p, &p);
if (val != NULL) /* Value history reference */
{
if (TYPE_CODE (value_type (val)) == TYPE_CODE_INT)
retval = value_as_long (val);
else
error (_("History value must have integer type."));
}
else /* Convenience variable */
{
/* Internal variable. Make a copy of the name, so we can
null-terminate it to pass to lookup_internalvar(). */
const char *start = ++p;
while (isalnum (*p) || *p == '_')
p++;
std::string varname (start, p - start);
if (!get_internalvar_integer (lookup_internalvar (varname.c_str ()),
&retval))
error (_("Convenience variable $%s does not have integer value."),
varname.c_str ());
}
}
else
{
retval = strtoulst (p, pp, 0);
if (p == *pp)
{
/* There is no number here. (e.g. "cond a == b"). */
error (_("Expected integer at: %s"), p);
}
p = *pp;
}
if (!(isspace (*p) || *p == '\0' || *p == trailer))
error (_("Trailing junk at: %s"), p);
p = skip_spaces (p);
*pp = p;
return retval;
}
/* See documentation in cli-utils.h. */
int
get_number_trailer (const char **pp, int trailer)
{
int retval = 0; /* default */
const char *p = *pp;
bool negative = false;
if (*p == '-')
{
++p;
negative = true;
}
if (*p == '$')
{
struct value *val = value_from_history_ref (p, &p);
if (val) /* Value history reference */
{
if (TYPE_CODE (value_type (val)) == TYPE_CODE_INT)
retval = value_as_long (val);
else
{
printf_filtered (_("History value must have integer type.\n"));
retval = 0;
}
}
else /* Convenience variable */
{
/* Internal variable. Make a copy of the name, so we can
null-terminate it to pass to lookup_internalvar(). */
char *varname;
const char *start = ++p;
LONGEST longest_val;
while (isalnum (*p) || *p == '_')
p++;
varname = (char *) alloca (p - start + 1);
strncpy (varname, start, p - start);
varname[p - start] = '\0';
if (get_internalvar_integer (lookup_internalvar (varname),
&longest_val))
retval = (int) longest_val;
else
{
printf_filtered (_("Convenience variable must "
"have integer value.\n"));
retval = 0;
}
}
}
else
{
const char *p1 = p;
while (*p >= '0' && *p <= '9')
++p;
if (p == p1)
/* There is no number here. (e.g. "cond a == b"). */
{
/* Skip non-numeric token. */
while (*p && !isspace((int) *p))
++p;
/* Return zero, which caller must interpret as error. */
retval = 0;
}
else
retval = atoi (p1);
}
if (!(isspace (*p) || *p == '\0' || *p == trailer))
{
/* Trailing junk: return 0 and let caller print error msg. */
while (!(isspace (*p) || *p == '\0' || *p == trailer))
++p;
retval = 0;
}
p = skip_spaces (p);
*pp = p;
return negative ? -retval : retval;
}
/* See documentation in cli-utils.h. */
int
get_number (const char **pp)
{
return get_number_trailer (pp, '\0');
}
/* See documentation in cli-utils.h. */
int
get_number (char **pp)
{
int result;
const char *p = *pp;
result = get_number_trailer (&p, '\0');
*pp = (char *) p;
return result;
}
/* See documentation in cli-utils.h. */
bool
extract_info_print_args (const char **args,
bool *quiet,
std::string *regexp,
std::string *t_regexp)
{
/* Check for NAMEREGEXP or -- NAMEREGEXP. */
if (**args != '-' || check_for_argument (args, "--", 2))
{
*regexp = *args;
*args = NULL;
return true;
}
if (check_for_argument (args, "-t", 2))
{
*t_regexp = extract_arg_maybe_quoted (args);
*args = skip_spaces (*args);
return true;
}
if (check_for_argument (args, "-q", 2))
{
*quiet = true;
return true;
}
return false;
}
/* See documentation in cli-utils.h. */
void
report_unrecognized_option_error (const char *command, const char *args)
{
std::string option = extract_arg (&args);
error (_("Unrecognized option '%s' to %s command. "
"Try \"help %s\"."), option.c_str (),
command, command);
}
/* See documentation in cli-utils.h. */
const char *
info_print_args_help (const char *prefix,
const char *entity_kind)
{
return xstrprintf (_("\
%sIf NAMEREGEXP is provided, only prints the %s whose name\n\
matches NAMEREGEXP.\n\
If -t TYPEREGEXP is provided, only prints the %s whose type\n\
matches TYPEREGEXP. Note that the matching is done with the type\n\
printed by the 'whatis' command.\n\
By default, the command might produce headers and/or messages indicating\n\
why no %s can be printed.\n\
The flag -q disables the production of these headers and messages."),
prefix, entity_kind, entity_kind, entity_kind);
}
/* See documentation in cli-utils.h. */
number_or_range_parser::number_or_range_parser (const char *string)
{
init (string);
}
/* See documentation in cli-utils.h. */
void
number_or_range_parser::init (const char *string)
{
m_cur_tok = string;
m_last_retval = 0;
m_end_value = 0;
m_end_ptr = NULL;
m_in_range = false;
}
/* See documentation in cli-utils.h. */
int
number_or_range_parser::get_number ()
{
if (m_in_range)
{
/* All number-parsing has already been done. Return the next
integer value (one greater than the saved previous value).
Do not advance the token pointer until the end of range is
reached. */
if (++m_last_retval == m_end_value)
{
/* End of range reached; advance token pointer. */
m_cur_tok = m_end_ptr;
m_in_range = false;
}
}
else if (*m_cur_tok != '-')
{
/* Default case: state->m_cur_tok is pointing either to a solo
number, or to the first number of a range. */
m_last_retval = get_number_trailer (&m_cur_tok, '-');
/* If get_number_trailer has found a '-' preceded by a space, it
might be the start of a command option. So, do not parse a
range if the '-' is followed by an alpha or another '-'. We
might also be completing something like
"frame apply level 0 -" and we prefer treating that "-" as an
option rather than an incomplete range, so check for end of
string as well. */
if (m_cur_tok[0] == '-'
&& !(isspace (m_cur_tok[-1])
&& (isalpha (m_cur_tok[1])
|| m_cur_tok[1] == '-'
|| m_cur_tok[1] == '\0')))
{
const char **temp;
/* This is the start of a range (<number1> - <number2>).
Skip the '-', parse and remember the second number,
and also remember the end of the final token. */
temp = &m_end_ptr;
m_end_ptr = skip_spaces (m_cur_tok + 1);
m_end_value = ::get_number (temp);
if (m_end_value < m_last_retval)
{
error (_("inverted range"));
}
else if (m_end_value == m_last_retval)
{
/* Degenerate range (number1 == number2). Advance the
token pointer so that the range will be treated as a
single number. */
m_cur_tok = m_end_ptr;
}
else
m_in_range = true;
}
}
else
{
if (isdigit (*(m_cur_tok + 1)))
error (_("negative value"));
if (*(m_cur_tok + 1) == '$')
{
/* Convenience variable. */
m_last_retval = ::get_number (&m_cur_tok);
if (m_last_retval < 0)
error (_("negative value"));
}
}
return m_last_retval;
}
/* See documentation in cli-utils.h. */
void
number_or_range_parser::setup_range (int start_value, int end_value,
const char *end_ptr)
{
gdb_assert (start_value > 0);
m_in_range = true;
m_end_ptr = end_ptr;
m_last_retval = start_value - 1;
m_end_value = end_value;
}
/* See documentation in cli-utils.h. */
bool
number_or_range_parser::finished () const
{
/* Parsing is finished when at end of string or null string,
or we are not in a range and not in front of an integer, negative
integer, convenience var or negative convenience var. */
return (m_cur_tok == NULL || *m_cur_tok == '\0'
|| (!m_in_range
&& !(isdigit (*m_cur_tok) || *m_cur_tok == '$')
&& !(*m_cur_tok == '-'
&& (isdigit (m_cur_tok[1]) || m_cur_tok[1] == '$'))));
}
/* Accept a number and a string-form list of numbers such as is
accepted by get_number_or_range. Return TRUE if the number is
in the list.
By definition, an empty list includes all numbers. This is to
be interpreted as typing a command such as "delete break" with
no arguments. */
int
number_is_in_list (const char *list, int number)
{
if (list == NULL || *list == '\0')
return 1;
number_or_range_parser parser (list);
if (parser.finished ())
error (_("Arguments must be numbers or '$' variables."));
while (!parser.finished ())
{
int gotnum = parser.get_number ();
if (gotnum == 0)
error (_("Arguments must be numbers or '$' variables."));
if (gotnum == number)
return 1;
}
return 0;
}
/* See documentation in cli-utils.h. */
const char *
remove_trailing_whitespace (const char *start, const char *s)
{
while (s > start && isspace (*(s - 1)))
--s;
return s;
}
/* A helper function to extract an argument from *ARG. An argument is
delimited by whitespace, but it can also be optionally quoted.
The quoting and special characters are handled similarly to
the parsing done by gdb_argv.
The return value is empty if no argument was found. */
static std::string
extract_arg_maybe_quoted (const char **arg)
{
bool squote = false;
bool dquote = false;
bool bsquote = false;
std::string result;
const char *p = *arg;
/* Find the start of the argument. */
p = skip_spaces (p);
/* Parse p similarly to gdb_argv buildargv function. */
while (*p != '\0')
{
if (isspace (*p) && !squote && !dquote && !bsquote)
break;
else
{
if (bsquote)
{
bsquote = false;
result += *p;
}
else if (*p == '\\')
bsquote = true;
else if (squote)
{
if (*p == '\'')
squote = false;
else
result += *p;
}
else if (dquote)
{
if (*p == '"')
dquote = false;
else
result += *p;
}
else
{
if (*p == '\'')
squote = true;
else if (*p == '"')
dquote = true;
else
result += *p;
}
p++;
}
}
*arg = p;
return result;
}
/* See documentation in cli-utils.h. */
std::string
extract_arg (const char **arg)
{
const char *result;
if (!*arg)
return std::string ();
/* Find the start of the argument. */
*arg = skip_spaces (*arg);
if (!**arg)
return std::string ();
result = *arg;
/* Find the end of the argument. */
*arg = skip_to_space (*arg + 1);
if (result == *arg)
return std::string ();
return std::string (result, *arg - result);
}
/* See documentation in cli-utils.h. */
std::string
extract_arg (char **arg)
{
const char *arg_const = *arg;
std::string result;
result = extract_arg (&arg_const);
*arg += arg_const - *arg;
return result;
}
/* See documentation in cli-utils.h. */
int
check_for_argument (const char **str, const char *arg, int arg_len)
{
if (strncmp (*str, arg, arg_len) == 0
&& ((*str)[arg_len] == '\0' || isspace ((*str)[arg_len])))
{
*str += arg_len;
*str = skip_spaces (*str);
return 1;
}
return 0;
}
/* See documentation in cli-utils.h. */
int
parse_flags (const char **str, const char *flags)
{
const char *p = skip_spaces (*str);
if (p[0] == '-'
&& isalpha (p[1])
&& (p[2] == '\0' || isspace (p[2])))
{
const char pf = p[1];
const char *f = flags;
while (*f != '\0')
{
if (*f == pf)
{
*str = skip_spaces (p + 2);
return f - flags + 1;
}
f++;
}
}
return 0;
}
/* See documentation in cli-utils.h. */
bool
parse_flags_qcs (const char *which_command, const char **str,
qcs_flags *flags)
{
switch (parse_flags (str, "qcs"))
{
case 0:
return false;
case 1:
flags->quiet = true;
break;
case 2:
flags->cont = true;
break;
case 3:
flags->silent = true;
break;
default:
gdb_assert_not_reached ("int qcs flag out of bound");
}
if (flags->cont && flags->silent)
error (_("%s: -c and -s are mutually exclusive"), which_command);
return true;
}