xref: /qemu/scripts/meson-buildoptions.py (revision 727385c4) 
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
28SKIP_OPTIONS = {
29    "audio_drv_list",
30    "default_devices",
31    "docdir",
32    "fuzzing_engine",
33    "qemu_firmwarepath",
34    "qemu_suffix",
35    "sphinx_build",
36    "trace_file",
37}
38
39LINE_WIDTH = 76
40
41
42# Convert the default value of an option to the string used in
43# the help message
44def value_to_help(value):
45    if isinstance(value, list):
46        return ",".join(value)
47    if isinstance(value, bool):
48        return "enabled" if value else "disabled"
49    return str(value)
50
51
52def wrap(left, text, indent):
53    spaces = " " * indent
54    if len(left) >= indent:
55        yield left
56        left = spaces
57    else:
58        left = (left + spaces)[0:indent]
59    yield from textwrap.wrap(
60        text, width=LINE_WIDTH, initial_indent=left, subsequent_indent=spaces
61    )
62
63
64def sh_print(line=""):
65    print('  printf "%s\\n"', shlex.quote(line))
66
67
68def help_line(left, opt, indent, long):
69    right = f'{opt["description"]}'
70    if long:
71        value = value_to_help(opt["value"])
72        if value != "auto":
73            right += f" [{value}]"
74    if "choices" in opt and long:
75        choices = "/".join(sorted(opt["choices"]))
76        right += f" (choices: {choices})"
77    for x in wrap("  " + left, right, indent):
78        sh_print(x)
79
80
81# Return whether the option (a dictionary) can be used with
82# arguments.  Booleans can never be used with arguments;
83# combos allow an argument only if they accept other values
84# than "auto", "enabled", and "disabled".
85def allow_arg(opt):
86    if opt["type"] == "boolean":
87        return False
88    if opt["type"] != "combo":
89        return True
90    return not (set(opt["choices"]) <= {"auto", "disabled", "enabled"})
91
92
93def load_options(json):
94    json = [
95        x
96        for x in json
97        if x["section"] == "user"
98        and ":" not in x["name"]
99        and x["name"] not in SKIP_OPTIONS
100    ]
101    return sorted(json, key=lambda x: x["name"])
102
103
104def print_help(options):
105    print("meson_options_help() {")
106    for opt in options:
107        key = opt["name"].replace("_", "-")
108        # The first section includes options that have an arguments,
109        # and booleans (i.e., only one of enable/disable makes sense)
110        if opt["type"] == "boolean":
111            left = f"--disable-{key}" if opt["value"] else f"--enable-{key}"
112            help_line(left, opt, 27, False)
113        elif allow_arg(opt):
114            if opt["type"] == "combo" and "enabled" in opt["choices"]:
115                left = f"--enable-{key}[=CHOICE]"
116            else:
117                left = f"--enable-{key}=CHOICE"
118            help_line(left, opt, 27, True)
119
120    sh_print()
121    sh_print("Optional features, enabled with --enable-FEATURE and")
122    sh_print("disabled with --disable-FEATURE, default is enabled if available")
123    sh_print("(unless built with --without-default-features):")
124    sh_print()
125    for opt in options:
126        key = opt["name"].replace("_", "-")
127        if opt["type"] != "boolean" and not allow_arg(opt):
128            help_line(key, opt, 18, False)
129    print("}")
130
131
132def print_parse(options):
133    print("_meson_option_parse() {")
134    print("  case $1 in")
135    for opt in options:
136        key = opt["name"].replace("_", "-")
137        name = opt["name"]
138        if opt["type"] == "boolean":
139            print(f'    --enable-{key}) printf "%s" -D{name}=true ;;')
140            print(f'    --disable-{key}) printf "%s" -D{name}=false ;;')
141        else:
142            if opt["type"] == "combo" and "enabled" in opt["choices"]:
143                print(f'    --enable-{key}) printf "%s" -D{name}=enabled ;;')
144            if opt["type"] == "combo" and "disabled" in opt["choices"]:
145                print(f'    --disable-{key}) printf "%s" -D{name}=disabled ;;')
146            if allow_arg(opt):
147                print(f'    --enable-{key}=*) quote_sh "-D{name}=$2" ;;')
148    print("    *) return 1 ;;")
149    print("  esac")
150    print("}")
151
152
153options = load_options(json.load(sys.stdin))
154print("# This file is generated by meson-buildoptions.py, do not edit!")
155print_help(options)
156print_parse(options)
157