Allow setting project options from cross or native files

This allows adding a `[project options]` section to a cross or native file
that contains the options defined for a project in it's meson_option.txt
file.

7 files changed, 171 insertions, 2 deletions

diff --git a/docs/markdown/Machine-files.md b/docs/markdown/Machine-files.md
index 9011f79..26af44a 100644
--- a/docs/markdown/Machine-files.md
+++ b/docs/markdown/Machine-files.md
@@ -12,6 +12,7 @@ The following sections are allowed:
 - binaries
 - paths
 - properties
+- project options
 
 ### constants
 
@@ -166,6 +167,25 @@ section may contain random key value pairs accessed using the
 The properties section can contain any variable you like, and is accessed via
 `meson.get_external_property`, or `meson.get_cross_property`.
 
+### Project specific options
+
+*New in 0.54.0*
+
+Being able to set project specific options in a native or cross files can be
+done using the `[project options]` section of the specific file (if doing a
+cross build the options from the native file will be ignored)
+
+For setting options in supbprojects use the `<subproject>:project options`
+section instead.
+
+```ini
+[project options]
+build-tests = true
+
+[zlib:project options]
+build-tests = false
+```
+
 ## Loading multiple machine files
 
 Native files allow layering (cross files can be layered since meson 0.52.0).
diff --git a/docs/markdown/snippets/project_options_in_machine_files.md b/docs/markdown/snippets/project_options_in_machine_files.md
new file mode 100644
index 0000000..78b129a
--- /dev/null
+++ b/docs/markdown/snippets/project_options_in_machine_files.md
@@ -0,0 +1,37 @@
+## Project options can be set in native or cross files
+
+A new set of sections has been added to the cross and native files, `[project
+options]` and `[<subproject_name>:project options]`, where `subproject_name`
+is the name of a subproject. Any options that are allowed in the project can
+be set from this section. They have the lowest precedent, and will be
+overwritten by command line arguments.
+
+
+```meson
+option('foo', type : 'string', value : 'foo')
+```
+
+```ini
+[project options]
+foo = 'other val'
+```
+
+```console
+meson build --native-file my.ini
+```
+
+Will result in the option foo having the value `other val`,
+
+```console
+meson build --native-file my.ini -Dfoo='different val'
+```
+
+Will result in the option foo having the value `different val`,
+
+
+Subproject options are assigned like this:
+
+```ini
+[zlib:project options]
+foo = 'some val'
+```
diff --git a/mesonbuild/coredata.py b/mesonbuild/coredata.py
index e2a6954..49104a7 100644
--- a/mesonbuild/coredata.py
+++ b/mesonbuild/coredata.py
@@ -377,6 +377,7 @@ class CoreData:
         host_cache = DependencyCache(self.builtins_per_machine, MachineChoice.BUILD)
         self.deps = PerMachine(build_cache, host_cache)  # type: PerMachine[DependencyCache]
         self.compiler_check_cache = OrderedDict()
+
         # Only to print a warning if it changes between Meson invocations.
         self.config_files = self.__load_config_files(options, scratch_dir, 'native')
         self.builtin_options_libdir_cross_fixup()
@@ -734,7 +735,7 @@ class CoreData:
         if not self.is_cross_build():
             self.copy_build_options_from_regular_ones()
 
-    def set_default_options(self, default_options, subproject, env):
+    def set_default_options(self, default_options: T.Mapping[str, str], subproject: str, env: 'Environment') -> None:
         # Warn if the user is using two different ways of setting build-type
         # options that override each other
         if 'buildtype' in env.cmd_line_options and \
@@ -755,6 +756,13 @@ class CoreData:
                 k = subproject + ':' + k
             cmd_line_options[k] = v
 
+        # load the values for user options out of the appropriate machine file,
+        # then overload the command line
+        for k, v in env.user_options.get(subproject, {}).items():
+            if subproject:
+                k = '{}:{}'.format(subproject, k)
+            cmd_line_options[k] = v
+
         # Override project default_options using conf files (cross or native)
         for k, v in env.paths.host:
             if v is not None:
diff --git a/mesonbuild/environment.py b/mesonbuild/environment.py
index a82c8f8..c872aee 100644
--- a/mesonbuild/environment.py
+++ b/mesonbuild/environment.py
@@ -553,6 +553,9 @@ class Environment:
         # architecture, just the build and host architectures
         paths = PerMachineDefaultable()
 
+        # We only need one of these as project options are not per machine
+        user_options = {}
+
         ## Setup build machine defaults
 
         # Will be fully initialized later using compilers later.
@@ -565,12 +568,26 @@ class Environment:
 
         ## Read in native file(s) to override build machine configuration
 
+        def load_user_options():
+            for section in config.keys():
+                if section.endswith('project options'):
+                    if ':' in section:
+                        project = section.split(':')[0]
+                    else:
+                        project = ''
+                    user_options[project] = config.get(section, {})
+
         if self.coredata.config_files is not None:
             config = coredata.parse_machine_files(self.coredata.config_files)
             binaries.build = BinaryTable(config.get('binaries', {}))
             paths.build = Directories(**config.get('paths', {}))
             properties.build = Properties(config.get('properties', {}))
 
+            # Don't run this if there are any cross files, we don't want to use
+            # the native values if we're doing a cross build
+            if not self.coredata.cross_files:
+                load_user_options()
+
         ## Read in cross file(s) to override host machine configuration
 
         if self.coredata.cross_files:
@@ -582,6 +599,7 @@ class Environment:
             if 'target_machine' in config:
                 machines.target = MachineInfo.from_literal(config['target_machine'])
             paths.host = Directories(**config.get('paths', {}))
+            load_user_options()
 
         ## "freeze" now initialized configuration, and "save" to the class.
 
@@ -589,6 +607,7 @@ class Environment:
         self.binaries = binaries.default_missing()
         self.properties = properties.default_missing()
         self.paths = paths.default_missing()
+        self.user_options = user_options
 
         exe_wrapper = self.lookup_binary_entry(MachineChoice.HOST, 'exe_wrapper')
         if exe_wrapper is not None:
diff --git a/run_unittests.py b/run_unittests.py
index 2b0e4e1..9d96ce0 100755
--- a/run_unittests.py
+++ b/run_unittests.py
@@ -7672,7 +7672,10 @@ class NativeFileTests(BasePlatformTests):
             for section, entries in values.items():
                 f.write('[{}]\n'.format(section))
                 for k, v in entries.items():
-                    f.write("{}='{}'\n".format(k, v))
+                    if isinstance(v, bool):
+                        f.write("{}={}\n".format(k, v))
+                    else:
+                        f.write("{}='{}'\n".format(k, v))
         return filename
 
     def helper_create_binary_wrapper(self, binary, dir_=None, extra_args=None, **kwargs):
@@ -7996,6 +7999,54 @@ class NativeFileTests(BasePlatformTests):
         self.init(testcase, extra_args=['--native-file', config])
         self.build()
 
+    def test_user_options(self):
+        testcase = os.path.join(self.common_test_dir, '43 options')
+        for opt, value in [('testoption', 'some other val'), ('other_one', True),
+                           ('combo_opt', 'one'), ('array_opt', ['two']),
+                           ('integer_opt', 0)]:
+            config = self.helper_create_native_file({'project options': {opt: value}})
+            with self.assertRaises(subprocess.CalledProcessError) as cm:
+                self.init(testcase, extra_args=['--native-file', config])
+                self.assertRegex(cm.exception.stdout, r'Incorrect value to [a-z]+ option')
+
+    def test_user_options_command_line_overrides(self):
+        testcase = os.path.join(self.common_test_dir, '43 options')
+        config = self.helper_create_native_file({'project options': {'other_one': True}})
+        self.init(testcase, extra_args=['--native-file', config, '-Dother_one=false'])
+
+    def test_user_options_subproject(self):
+        testcase = os.path.join(self.unit_test_dir, '75 user options for subproject')
+
+        s = os.path.join(testcase, 'subprojects')
+        if not os.path.exists(s):
+            os.mkdir(s)
+        s = os.path.join(s, 'sub')
+        if not os.path.exists(s):
+            sub = os.path.join(self.common_test_dir, '43 options')
+            shutil.copytree(sub, s)
+
+        for opt, value in [('testoption', 'some other val'), ('other_one', True),
+                           ('combo_opt', 'one'), ('array_opt', ['two']),
+                           ('integer_opt', 0)]:
+            config = self.helper_create_native_file({'project options': {'sub:{}'.format(opt): value}})
+            with self.assertRaises(subprocess.CalledProcessError) as cm:
+                self.init(testcase, extra_args=['--native-file', config])
+                self.assertRegex(cm.exception.stdout, r'Incorrect value to [a-z]+ option')
+
+    def test_option_bool(self):
+        # Bools are allowed to be unquoted
+        testcase = os.path.join(self.common_test_dir, '1 trivial')
+        config = self.helper_create_native_file({'built-in options': {'werror': True}})
+        self.init(testcase, extra_args=['--native-file', config])
+        configuration = self.introspect('--buildoptions')
+        for each in configuration:
+            # Test that no-per subproject options are inherited from the parent
+            if 'werror' in each['name']:
+                self.assertEqual(each['value'], True)
+                break
+        else:
+            self.fail('Did not find werror in build options?')
+
 
 class CrossFileTests(BasePlatformTests):
 
@@ -8005,6 +8056,11 @@ class CrossFileTests(BasePlatformTests):
     This is mainly aimed to testing overrides from cross files.
     """
 
+    def setUp(self):
+        super().setUp()
+        self.current_config = 0
+        self.current_wrapper = 0
+
     def _cross_file_generator(self, *, needs_exe_wrapper: bool = False,
                               exe_wrapper: T.Optional[T.List[str]] = None) -> str:
         if is_windows():
@@ -8133,6 +8189,21 @@ class CrossFileTests(BasePlatformTests):
                     self.init(testdir, extra_args=['--cross-file=' + name], inprocess=True)
                     self.wipe()
 
+    def helper_create_cross_file(self, values):
+        """Create a config file as a temporary file.
+
+        values should be a nested dictionary structure of {section: {key:
+        value}}
+        """
+        filename = os.path.join(self.builddir, 'generated{}.config'.format(self.current_config))
+        self.current_config += 1
+        with open(filename, 'wt') as f:
+            for section, entries in values.items():
+                f.write('[{}]\n'.format(section))
+                for k, v in entries.items():
+                    f.write("{}='{}'\n".format(k, v))
+        return filename
+
     def test_cross_file_dirs(self):
         testcase = os.path.join(self.unit_test_dir, '60 native file override')
         self.init(testcase, default_args=False,
@@ -8189,6 +8260,16 @@ class CrossFileTests(BasePlatformTests):
                               '-Ddef_sharedstatedir=sharedstatebar',
                               '-Ddef_sysconfdir=sysconfbar'])
 
+    def test_user_options(self):
+        # This is just a touch test for cross file, since the implementation
+        # shares code after loading from the files
+        testcase = os.path.join(self.common_test_dir, '43 options')
+        config = self.helper_create_cross_file({'project options': {'testoption': 'some other value'}})
+        with self.assertRaises(subprocess.CalledProcessError) as cm:
+            self.init(testcase, extra_args=['--native-file', config])
+            self.assertRegex(cm.exception.stdout, r'Incorrect value to [a-z]+ option')
+
+
 class TAPParserTests(unittest.TestCase):
     def assert_test(self, events, **kwargs):
         if 'explanation' not in kwargs:
diff --git a/test cases/unit/75 user options for subproject/.gitignore b/test cases/unit/75 user options for subproject/.gitignore
new file mode 100644
index 0000000..4976afc
--- /dev/null
+++ b/test cases/unit/75 user options for subproject/.gitignore
@@ -0,0 +1 @@
+subprojects/*
diff --git a/test cases/unit/75 user options for subproject/meson.build b/test cases/unit/75 user options for subproject/meson.build
new file mode 100644
index 0000000..0bc395b
--- /dev/null
+++ b/test cases/unit/75 user options for subproject/meson.build
@@ -0,0 +1,3 @@
+project('user option for subproject')
+
+p = subproject('sub')