configure: automatically parse command line for meson -D options
Right now meson_options.txt lists about 90 options. Each option
needs code in configure to parse it and pass the option down to Meson as
a -D command-line argument; in addition the default must be duplicated
between configure and meson_options.txt. This series tries to remove
the code duplication by generating the case statement for those --enable
and --disable options, as well as the corresponding help text.
About 80% of the options can be handled completely by the new mechanism.
Eight meson options are not of the --enable/--disable kind. Six more need
to be parsed in configure for various reasons documented in the patch,
but they still have their help automatically generated.
The advantages are:
- less code in configure
- parsing and help is more consistent (for example --enable-blobs was
not supported)
- options are described entirely in one place, meson_options.txt.
This make it more attractive to use Meson options instead of
hand-crafted configure options and config-host.mak
A few options change name: --enable-tcmalloc and --enable-jemalloc
become --enable-malloc={tcmalloc,jemalloc}; --disable-blobs becomes
--disable-install-blobs; --enable-trace-backend becomes
--enable-trace-backends. However, the old names are allowed
for backwards compatibility.
Message-Id: <20211007130829.632254-19-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/scripts/meson-buildoptions.py b/scripts/meson-buildoptions.py
index d48af99..256523c 100755
--- a/scripts/meson-buildoptions.py
+++ b/scripts/meson-buildoptions.py
@@ -25,10 +25,71 @@
import shlex
import sys
+SKIP_OPTIONS = {
+ "audio_drv_list",
+ "default_devices",
+ "docdir",
+ "fuzzing_engine",
+ "qemu_firmwarepath",
+ "qemu_suffix",
+ "sphinx_build",
+ "trace_file",
+}
+
+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":
+ 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"})
+
+
def load_options(json):
json = [
x
@@ -42,17 +103,48 @@
def print_help(options):
print("meson_options_help() {")
+ for opt in options:
+ key = opt["name"].replace("_", "-")
+ # The first section includes options that have an arguments,
+ # and booleans (i.e., only one of enable/disable makes sense)
+ if opt["type"] == "boolean":
+ left = f"--disable-{key}" if opt["value"] else f"--enable-{key}"
+ help_line(left, opt, 27, False)
+ elif allow_arg(opt):
+ if opt["type"] == "combo" and "enabled" in opt["choices"]:
+ left = f"--enable-{key}[=CHOICE]"
+ else:
+ left = f"--enable-{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 = opt["name"].replace("_", "-")
+ name = opt["name"]
+ if 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("}")