xref: /qemu/scripts/meson-buildoptions.py (revision 79fccf7e) 
1#! /usr/bin/env python3
2
3# Generate configure command line options handling code, based on Meson's
4# user build options introspection data
5#
6# Copyright (C) 2021 Red Hat, Inc.
7#
8# Author: Paolo Bonzini <pbonzini@redhat.com>
9#
10# This program is free software; you can redistribute it and/or modify
11# it under the terms of the GNU General Public License as published by
12# the Free Software Foundation; either version 2, or (at your option)
13# any later version.
14#
15# This program is distributed in the hope that it will be useful,
16# but WITHOUT ANY WARRANTY; without even the implied warranty of
17# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18# GNU General Public License for more details.
19#
20# You should have received a copy of the GNU General Public License
21# along with this program.  If not, see <https://www.gnu.org/licenses/>.
22
23import json
24import textwrap
25import shlex
26import sys
27
28# Options with nonstandard names (e.g. --with/--without) or OS-dependent
29# defaults.  Try not to add any.
30SKIP_OPTIONS = {
31    "default_devices",
32    "fuzzing_engine",
33}
34
35# Options whose name doesn't match the option for backwards compatibility
36# reasons, because Meson gives them a funny name, or both
37OPTION_NAMES = {
38    "b_coverage": "gcov",
39    "b_lto": "lto",
40    "coroutine_backend": "with-coroutine",
41    "debug": "debug-info",
42    "malloc": "enable-malloc",
43    "pkgversion": "with-pkgversion",
44    "qemu_firmwarepath": "firmwarepath",
45    "qemu_suffix": "with-suffix",
46    "trace_backends": "enable-trace-backends",
47    "trace_file": "with-trace-file",
48}
49
50# Options that configure autodetects, even though meson defines them as boolean
51AUTO_OPTIONS = {
52    "plugins",
53    "werror",
54}
55
56# Builtin options that should be definable via configure.  Some of the others
57# we really do not want (e.g. c_args is defined via the native file, not
58# via -D, because it's a mix of CFLAGS and --extra-cflags); for specific
59# cases "../configure -D" can be used as an escape hatch.
60BUILTIN_OPTIONS = {
61    "b_coverage",
62    "b_lto",
63    "bindir",
64    "datadir",
65    "debug",
66    "includedir",
67    "libdir",
68    "libexecdir",
69    "localedir",
70    "localstatedir",
71    "mandir",
72    "prefix",
73    "strip",
74    "sysconfdir",
75    "werror",
76}
77
78LINE_WIDTH = 76
79
80
81# Convert the default value of an option to the string used in
82# the help message
83def get_help(opt):
84    if opt["name"] == "libdir":
85        return 'system default'
86    value = opt["value"]
87    if isinstance(value, list):
88        return ",".join(value)
89    if isinstance(value, bool):
90        return "enabled" if value else "disabled"
91    return str(value)
92
93
94def wrap(left, text, indent):
95    spaces = " " * indent
96    if len(left) >= indent:
97        yield left
98        left = spaces
99    else:
100        left = (left + spaces)[0:indent]
101    yield from textwrap.wrap(
102        text, width=LINE_WIDTH, initial_indent=left, subsequent_indent=spaces
103    )
104
105
106def sh_print(line=""):
107    print('  printf "%s\\n"', shlex.quote(line))
108
109
110def help_line(left, opt, indent, long):
111    right = f'{opt["description"]}'
112    if long:
113        value = get_help(opt)
114        if value != "auto" and value != "":
115            right += f" [{value}]"
116    if "choices" in opt and long:
117        choices = "/".join(sorted(opt["choices"]))
118        right += f" (choices: {choices})"
119    for x in wrap("  " + left, right, indent):
120        sh_print(x)
121
122
123# Return whether the option (a dictionary) can be used with
124# arguments.  Booleans can never be used with arguments;
125# combos allow an argument only if they accept other values
126# than "auto", "enabled", and "disabled".
127def allow_arg(opt):
128    if opt["type"] == "boolean":
129        return False
130    if opt["type"] != "combo":
131        return True
132    return not (set(opt["choices"]) <= {"auto", "disabled", "enabled"})
133
134
135# Return whether the option (a dictionary) can be used without
136# arguments.  Booleans can only be used without arguments;
137# combos require an argument if they accept neither "enabled"
138# nor "disabled"
139def require_arg(opt):
140    if opt["type"] == "boolean":
141        return False
142    if opt["type"] != "combo":
143        return True
144    return not ({"enabled", "disabled"}.intersection(opt["choices"]))
145
146
147def filter_options(json):
148    if ":" in json["name"]:
149        return False
150    if json["section"] == "user":
151        return json["name"] not in SKIP_OPTIONS
152    else:
153        return json["name"] in BUILTIN_OPTIONS
154
155
156def load_options(json):
157    json = [x for x in json if filter_options(x)]
158    return sorted(json, key=lambda x: x["name"])
159
160
161def cli_option(opt):
162    name = opt["name"]
163    if name in OPTION_NAMES:
164        return OPTION_NAMES[name]
165    return name.replace("_", "-")
166
167
168def cli_help_key(opt):
169    key = cli_option(opt)
170    if require_arg(opt):
171        return key
172    if opt["type"] == "boolean" and opt["value"]:
173        return f"disable-{key}"
174    return f"enable-{key}"
175
176
177def cli_metavar(opt):
178    if opt["type"] == "string":
179        return "VALUE"
180    if opt["type"] == "array":
181        return "CHOICES" if "choices" in opt else "VALUES"
182    return "CHOICE"
183
184
185def print_help(options):
186    print("meson_options_help() {")
187    feature_opts = []
188    for opt in sorted(options, key=cli_help_key):
189        key = cli_help_key(opt)
190        # The first section includes options that have an arguments,
191        # and booleans (i.e., only one of enable/disable makes sense)
192        if require_arg(opt):
193            metavar = cli_metavar(opt)
194            left = f"--{key}={metavar}"
195            help_line(left, opt, 27, True)
196        elif opt["type"] == "boolean" and opt["name"] not in AUTO_OPTIONS:
197            left = f"--{key}"
198            help_line(left, opt, 27, False)
199        elif allow_arg(opt):
200            if opt["type"] == "combo" and "enabled" in opt["choices"]:
201                left = f"--{key}[=CHOICE]"
202            else:
203                left = f"--{key}=CHOICE"
204            help_line(left, opt, 27, True)
205        else:
206            feature_opts.append(opt)
207
208    sh_print()
209    sh_print("Optional features, enabled with --enable-FEATURE and")
210    sh_print("disabled with --disable-FEATURE, default is enabled if available")
211    sh_print("(unless built with --without-default-features):")
212    sh_print()
213    for opt in sorted(feature_opts, key=cli_option):
214        key = cli_option(opt)
215        help_line(key, opt, 18, False)
216    print("}")
217
218
219def print_parse(options):
220    print("_meson_option_parse() {")
221    print("  case $1 in")
222    for opt in options:
223        key = cli_option(opt)
224        name = opt["name"]
225        if require_arg(opt):
226            if opt["type"] == "array" and not "choices" in opt:
227                print(f'    --{key}=*) quote_sh "-D{name}=$(meson_option_build_array $2)" ;;')
228            else:
229                print(f'    --{key}=*) quote_sh "-D{name}=$2" ;;')
230        elif opt["type"] == "boolean":
231            print(f'    --enable-{key}) printf "%s" -D{name}=true ;;')
232            print(f'    --disable-{key}) printf "%s" -D{name}=false ;;')
233        else:
234            if opt["type"] == "combo" and "enabled" in opt["choices"]:
235                print(f'    --enable-{key}) printf "%s" -D{name}=enabled ;;')
236            if opt["type"] == "combo" and "disabled" in opt["choices"]:
237                print(f'    --disable-{key}) printf "%s" -D{name}=disabled ;;')
238            if allow_arg(opt):
239                print(f'    --enable-{key}=*) quote_sh "-D{name}=$2" ;;')
240    print("    *) return 1 ;;")
241    print("  esac")
242    print("}")
243
244
245options = load_options(json.load(sys.stdin))
246print("# This file is generated by meson-buildoptions.py, do not edit!")
247print_help(options)
248print_parse(options)
249