mesonbuild: allow multiple --cross-file options

Just like --native-file, allow multiple --cross-file options.  This is mostly
unifying the logic between cross_files and config_files.

docs/markdown/snippets/multiple-cross-files.md

@@ -0,0 +1,3 @@
+## Multipe cross files can be specified
+
+`--cross-file` can be passed multiple times, with the configuration files overlaying the same way as `--native-file`.

mesonbuild/backend/backends.py

@@ -788,8 +788,7 @@ class Backend:
         deps = [os.path.join(self.build_to_src, df)
                 for df in self.interpreter.get_build_def_files()]
         if self.environment.is_cross_build():
-            deps.append(os.path.join(self.build_to_src,
-                                     self.environment.coredata.cross_file))
+            deps.extend(self.environment.coredata.cross_files)
         deps.append('meson-private/coredata.dat')
         if os.path.exists(os.path.join(self.environment.get_source_dir(), 'meson_options.txt')):
             deps.append(os.path.join(self.build_to_src, 'meson_options.txt'))

mesonbuild/coredata.py

@@ -265,7 +265,7 @@ class CoreData:
         self.compiler_options = PerMachine({}, {}, {})
         self.base_options = {}
         self.external_preprocess_args = PerMachine({}, {}, {}) # CPPFLAGS only
-        self.cross_file = self.__load_cross_file(options.cross_file)
+        self.cross_files = self.__load_config_files(options.cross_file)
         self.compilers = OrderedDict()
         self.cross_compilers = OrderedDict()
         self.deps = OrderedDict()
@@ -276,57 +276,19 @@ class CoreData:
 
     @staticmethod
     def __load_config_files(filenames):
+        # Need to try and make the passed filenames absolute because when the
+        # files are parsed later we'll have chdir()d.
         if not filenames:
             return []
         filenames = [os.path.abspath(os.path.expanduser(os.path.expanduser(f)))
                      for f in filenames]
         return filenames
 
-    @staticmethod
-    def __load_cross_file(filename):
-        """Try to load the cross file.
-
-        If the filename is None return None. If the filename is an absolute
-        (after resolving variables and ~), return that absolute path. Next,
-        check if the file is relative to the current source dir. If the path
-        still isn't resolved do the following:
-            Windows:
-                - Error
-            *:
-                - $XDG_DATA_HOME/meson/cross (or ~/.local/share/meson/cross if
-                  undefined)
-                - $XDG_DATA_DIRS/meson/cross (or
-                  /usr/local/share/meson/cross:/usr/share/meson/cross if undefined)
-                - Error
-
-        Non-Windows follows the Linux path and will honor XDG_* if set. This
-        simplifies the implementation somewhat.
-        """
-        if filename is None:
-            return None
-        filename = os.path.expanduser(os.path.expandvars(filename))
-        if os.path.isabs(filename):
-            return filename
-        path_to_try = os.path.abspath(filename)
-        if os.path.isfile(path_to_try):
-            return path_to_try
-        if sys.platform != 'win32':
-            paths = [
-                os.environ.get('XDG_DATA_HOME', os.path.expanduser('~/.local/share')),
-            ] + os.environ.get('XDG_DATA_DIRS', '/usr/local/share:/usr/share').split(':')
-            for path in paths:
-                path_to_try = os.path.join(path, 'meson', 'cross', filename)
-                if os.path.isfile(path_to_try):
-                    return path_to_try
-            raise MesonException('Cannot find specified cross file: ' + filename)
-
-        raise MesonException('Cannot find specified cross file: ' + filename)
-
     def libdir_cross_fixup(self):
         # By default set libdir to "lib" when cross compiling since
         # getting the "system default" is always wrong on multiarch
         # platforms as it gets a value like lib/x86_64-linux-gnu.
-        if self.cross_file is not None:
+        if self.cross_files:
             self.builtins['libdir'].value = 'lib'
 
     def sanitize_prefix(self, prefix):
@@ -642,8 +604,8 @@ def read_cmd_line_file(build_dir, options):
     options.cmd_line_options = d
 
     properties = config['properties']
-    if options.cross_file is None:
-        options.cross_file = properties.get('cross_file', None)
+    if not options.cross_file:
+        options.cross_file = ast.literal_eval(properties.get('cross_file', '[]'))
     if not options.native_file:
         # This will be a string in the form: "['first', 'second', ...]", use
         # literal_eval to get it into the list of strings.
@@ -654,7 +616,7 @@ def write_cmd_line_file(build_dir, options):
     config = CmdLineFileParser()
 
     properties = {}
-    if options.cross_file is not None:
+    if options.cross_file:
         properties['cross_file'] = options.cross_file
     if options.native_file:
         properties['native_file'] = options.native_file

mesonbuild/environment.py

@@ -412,8 +412,9 @@ class Environment:
             self.binaries.build = BinaryTable(config.get('binaries', {}))
             self.paths.build = Directories(**config.get('paths', {}))
 
-        if self.coredata.cross_file is not None:
-            config = MesonConfigFile.parse_datafile(self.coredata.cross_file)
+        if self.coredata.cross_files:
+            config = MesonConfigFile.from_config_parser(
+                coredata.load_configs(self.coredata.cross_files, 'cross'))
             self.properties.host = Properties(config.get('properties', {}), False)
             self.binaries.host = BinaryTable(config.get('binaries', {}), False)
             if 'host_machine' in config:

mesonbuild/msetup.py

@@ -29,7 +29,9 @@ from .mesonlib import MesonException
 
 def add_arguments(parser):
     coredata.register_builtin_arguments(parser)
-    parser.add_argument('--cross-file', default=None,
+    parser.add_argument('--cross-file',
+                        default=[],
+                        action='append',
                         help='File describing cross compilation environment.')
     parser.add_argument('--native-file',
                         default=[],

mesonbuild/munstable_coredata.py

@@ -81,8 +81,9 @@ def run(options):
             print('Last seen PKGCONFIG enviroment variable value: ' + v)
         elif k == 'version':
             print('Meson version: ' + v)
-        elif k == 'cross_file':
-            print('Cross File: ' + (v or 'None'))
+        elif k == 'cross_files':
+            if v:
+                print('Cross File: ' + ' '.join(v))
         elif k == 'config_files':
             if v:
                 print('Native File: ' + ' '.join(v))