mdist: use better approach to finding original configured options

Instead of reading intro-buildoptions.json, a giant json file containing
every option ever + its current value, use the private file that is
internally used by msetup for e.g. --wipe to restore settings.

This accurately tracks exactly the options specified on the command
line, and avoids lengthy summary messages containing all the overridden
defaults.

It also avoids passing potentially incompatible options, such as
explictly specifying -Dpython.install_env while also having a non-empty
-Dpython.{x}libdir

Fixes #10181

mesonbuild/mdist.py

@@ -13,9 +13,11 @@
 # limitations under the License.
 
 
+import argparse
 import gzip
 import os
 import sys
+import shlex
 import shutil
 import subprocess
 import tarfile
@@ -27,8 +29,9 @@ from pathlib import Path
 from mesonbuild.environment import detect_ninja
 from mesonbuild.mesonlib import (MesonException, RealPathAction, quiet_git,
                                  windows_proof_rmtree, setup_vsenv)
+from mesonbuild.msetup import add_arguments as msetup_argparse
 from mesonbuild.wrap import wrap
-from mesonbuild import mlog, build
+from mesonbuild import mlog, build, coredata
 from .scripts.meson_exe import run_exe
 
 archive_choices = ['gztar', 'xztar', 'zip']
@@ -251,9 +254,7 @@ def check_dist(packagename, meson_command, extra_meson_args, bld_root, privdir):
     unpacked_files = glob(os.path.join(unpackdir, '*'))
     assert len(unpacked_files) == 1
     unpacked_src_dir = unpacked_files[0]
-    with open(os.path.join(bld_root, 'meson-info', 'intro-buildoptions.json'), encoding='utf-8') as boptions:
-        meson_command += ['-D{name}={value}'.format(**o) for o in json.load(boptions)
-                          if o['name'] not in ['backend', 'install_umask', 'buildtype']]
+    meson_command += create_cmdline_args(bld_root)
     meson_command += extra_meson_args
 
     ret = run_dist_steps(meson_command, unpacked_src_dir, builddir, installdir, ninja_args)
@@ -266,6 +267,15 @@ def check_dist(packagename, meson_command, extra_meson_args, bld_root, privdir):
         print(f'Distribution package {packagename} tested')
     return ret
 
+def create_cmdline_args(bld_root):
+    parser = argparse.ArgumentParser()
+    msetup_argparse(parser)
+    args = parser.parse_args([])
+    coredata.parse_cmd_line_options(args)
+    coredata.read_cmd_line_file(bld_root, args)
+    args.cmd_line_options.pop(coredata.OptionKey('backend'), '')
+    return shlex.split(coredata.format_cmd_line_options(args))
+
 def determine_archives_to_generate(options):
     result = []
     for i in options.formats.split(','):