1 files changed, 224 insertions, 0 deletions
diff --git a/scripts/meson-buildoptions.py b/scripts/meson-buildoptions.py
new file mode 100755
index 00000000..3e2b4785
--- /dev/null
+++ b/scripts/meson-buildoptions.py
@@ -0,0 +1,224 @@
+#! /usr/bin/env python3
+
+# Generate configure command line options handling code, based on Meson's
+# user build options introspection data
+#
+# Copyright (C) 2021 Red Hat, Inc.
+#
+# Author: Paolo Bonzini <pbonzini@redhat.com>
+#
+# 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 2, 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 <https://www.gnu.org/licenses/>.
+
+import json
+import textwrap
+import shlex
+import sys
+
+SKIP_OPTIONS = {
+    "default_devices",
+    "fuzzing_engine",
+    "qemu_suffix",
+    "smbd",
+}
+
+OPTION_NAMES = {
+    "b_coverage": "gcov",
+    "b_lto": "lto",
+    "malloc": "enable-malloc",
+    "pkgversion": "with-pkgversion",
+    "qemu_firmwarepath": "firmwarepath",
+    "trace_backends": "enable-trace-backends",
+    "trace_file": "with-trace-file",
+}
+
+BUILTIN_OPTIONS = {
+    "b_coverage",
+    "b_lto",
+    "datadir",
+    "includedir",
+    "libdir",
+    "libexecdir",
+    "localedir",
+    "localstatedir",
+    "mandir",
+    "strip",
+    "sysconfdir",
+}
+
+LINE_WIDTH = 76
+
+
+# Convert the default value of an option to the string used in
+# the help message
+def value_to_help(value):
+    if isinstance(value, list):
+        return ",".join(value)
+    if isinstance(value, bool):
+        return "enabled" if value else "disabled"
+    return str(value)
+
+
+def wrap(left, text, indent):
+    spaces = " " * indent
+    if len(left) >= indent:
+        yield left
+        left = spaces
+    else:
+        left = (left + spaces)[0:indent]
+    yield from textwrap.wrap(
+        text, width=LINE_WIDTH, initial_indent=left, subsequent_indent=spaces
+    )
+
+
+def sh_print(line=""):
+    print('  printf "%s\\n"', shlex.quote(line))
+
+
+def help_line(left, opt, indent, long):
+    right = f'{opt["description"]}'
+    if long:
+        value = value_to_help(opt["value"])
+        if value != "auto" and value != "":
+            right += f" [{value}]"
+    if "choices" in opt and long:
+        choices = "/".join(sorted(opt["choices"]))
+        right += f" (choices: {choices})"
+    for x in wrap("  " + left, right, indent):
+        sh_print(x)
+
+
+# Return whether the option (a dictionary) can be used with
+# arguments.  Booleans can never be used with arguments;
+# combos allow an argument only if they accept other values
+# than "auto", "enabled", and "disabled".
+def allow_arg(opt):
+    if opt["type"] == "boolean":
+        return False
+    if opt["type"] != "combo":
+        return True
+    return not (set(opt["choices"]) <= {"auto", "disabled", "enabled"})
+
+
+# Return whether the option (a dictionary) can be used without
+# arguments.  Booleans can only be used without arguments;
+# combos require an argument if they accept neither "enabled"
+# nor "disabled"
+def require_arg(opt):
+    if opt["type"] == "boolean":
+        return False
+    if opt["type"] != "combo":
+        return True
+    return not ({"enabled", "disabled"}.intersection(opt["choices"]))
+
+
+def filter_options(json):
+    if ":" in json["name"]:
+        return False
+    if json["section"] == "user":
+        return json["name"] not in SKIP_OPTIONS
+    else:
+        return json["name"] in BUILTIN_OPTIONS
+
+
+def load_options(json):
+    json = [x for x in json if filter_options(x)]
+    return sorted(json, key=lambda x: x["name"])
+
+
+def cli_option(opt):
+    name = opt["name"]
+    if name in OPTION_NAMES:
+        return OPTION_NAMES[name]
+    return name.replace("_", "-")
+
+
+def cli_help_key(opt):
+    key = cli_option(opt)
+    if require_arg(opt):
+        return key
+    if opt["type"] == "boolean" and opt["value"]:
+        return f"disable-{key}"
+    return f"enable-{key}"
+
+
+def cli_metavar(opt):
+    if opt["type"] == "string":
+        return "VALUE"
+    if opt["type"] == "array":
+        return "CHOICES" if "choices" in opt else "VALUES"
+    return "CHOICE"
+
+
+def print_help(options):
+    print("meson_options_help() {")
+    for opt in sorted(options, key=cli_help_key):
+        key = cli_help_key(opt)
+        # The first section includes options that have an arguments,
+        # and booleans (i.e., only one of enable/disable makes sense)
+        if require_arg(opt):
+            metavar = cli_metavar(opt)
+            left = f"--{key}={metavar}"
+            help_line(left, opt, 27, True)
+        elif opt["type"] == "boolean":
+            left = f"--{key}"
+            help_line(left, opt, 27, False)
+        elif allow_arg(opt):
+            if opt["type"] == "combo" and "enabled" in opt["choices"]:
+                left = f"--{key}[=CHOICE]"
+            else:
+                left = f"--{key}=CHOICE"
+            help_line(left, opt, 27, True)
+
+    sh_print()
+    sh_print("Optional features, enabled with --enable-FEATURE and")
+    sh_print("disabled with --disable-FEATURE, default is enabled if available")
+    sh_print("(unless built with --without-default-features):")
+    sh_print()
+    for opt in options:
+        key = opt["name"].replace("_", "-")
+        if opt["type"] != "boolean" and not allow_arg(opt):
+            help_line(key, opt, 18, False)
+    print("}")
+
+
+def print_parse(options):
+    print("_meson_option_parse() {")
+    print("  case $1 in")
+    for opt in options:
+        key = cli_option(opt)
+        name = opt["name"]
+        if require_arg(opt):
+            if opt["type"] == "array" and not "choices" in opt:
+                print(f'    --{key}=*) quote_sh "-D{name}=$(meson_option_build_array $2)" ;;')
+            else:
+                print(f'    --{key}=*) quote_sh "-D{name}=$2" ;;')
+        elif opt["type"] == "boolean":
+            print(f'    --enable-{key}) printf "%s" -D{name}=true ;;')
+            print(f'    --disable-{key}) printf "%s" -D{name}=false ;;')
+        else:
+            if opt["type"] == "combo" and "enabled" in opt["choices"]:
+                print(f'    --enable-{key}) printf "%s" -D{name}=enabled ;;')
+            if opt["type"] == "combo" and "disabled" in opt["choices"]:
+                print(f'    --disable-{key}) printf "%s" -D{name}=disabled ;;')
+            if allow_arg(opt):
+                print(f'    --enable-{key}=*) quote_sh "-D{name}=$2" ;;')
+    print("    *) return 1 ;;")
+    print("  esac")
+    print("}")
+
+
+options = load_options(json.load(sys.stdin))
+print("# This file is generated by meson-buildoptions.py, do not edit!")
+print_help(options)
+print_parse(options)