deps: Split dependencies.base

Split the Factory and dependency classes out
of the base.py script to improve maintainability.

1 files changed, 472 insertions, 0 deletions

diff --git a/mesonbuild/dependencies/pkgconfig.py b/mesonbuild/dependencies/pkgconfig.py
new file mode 100644
index 0000000..de55d3e
--- /dev/null
+++ b/mesonbuild/dependencies/pkgconfig.py
@@ -0,0 +1,472 @@
+# Copyright 2013-2021 The Meson development team
+
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+
+#     http://www.apache.org/licenses/LICENSE-2.0
+
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from .base import ExternalDependency, DependencyException, DependencyMethods, sort_libpaths
+from ..mesonlib import LibType, MachineChoice, OptionKey, OrderedSet, PerMachine, Popen_safe
+from ..programs import find_external_program
+from .. import mlog
+from pathlib import PurePath
+import re
+import os
+import shlex
+import typing as T
+
+if T.TYPE_CHECKING:
+    from ..environment import Environment
+
+class PkgConfigDependency(ExternalDependency):
+    # The class's copy of the pkg-config path. Avoids having to search for it
+    # multiple times in the same Meson invocation.
+    class_pkgbin = PerMachine(None, None)
+    # We cache all pkg-config subprocess invocations to avoid redundant calls
+    pkgbin_cache = {}
+
+    def __init__(self, name, environment: 'Environment', kwargs, language: T.Optional[str] = None):
+        super().__init__('pkgconfig', environment, kwargs, language=language)
+        self.name = name
+        self.is_libtool = False
+        # Store a copy of the pkg-config path on the object itself so it is
+        # stored in the pickled coredata and recovered.
+        self.pkgbin = None
+
+        # Only search for pkg-config for each machine the first time and store
+        # the result in the class definition
+        if PkgConfigDependency.class_pkgbin[self.for_machine] is False:
+            mlog.debug('Pkg-config binary for %s is cached as not found.' % self.for_machine)
+        elif PkgConfigDependency.class_pkgbin[self.for_machine] is not None:
+            mlog.debug('Pkg-config binary for %s is cached.' % self.for_machine)
+        else:
+            assert PkgConfigDependency.class_pkgbin[self.for_machine] is None
+            mlog.debug('Pkg-config binary for %s is not cached.' % self.for_machine)
+            for potential_pkgbin in find_external_program(
+                    self.env, self.for_machine, 'pkgconfig', 'Pkg-config',
+                    environment.default_pkgconfig, allow_default_for_cross=False):
+                version_if_ok = self.check_pkgconfig(potential_pkgbin)
+                if not version_if_ok:
+                    continue
+                if not self.silent:
+                    mlog.log('Found pkg-config:', mlog.bold(potential_pkgbin.get_path()),
+                             '(%s)' % version_if_ok)
+                PkgConfigDependency.class_pkgbin[self.for_machine] = potential_pkgbin
+                break
+            else:
+                if not self.silent:
+                    mlog.log('Found Pkg-config:', mlog.red('NO'))
+                # Set to False instead of None to signify that we've already
+                # searched for it and not found it
+                PkgConfigDependency.class_pkgbin[self.for_machine] = False
+
+        self.pkgbin = PkgConfigDependency.class_pkgbin[self.for_machine]
+        if self.pkgbin is False:
+            self.pkgbin = None
+            msg = 'Pkg-config binary for machine %s not found. Giving up.' % self.for_machine
+            if self.required:
+                raise DependencyException(msg)
+            else:
+                mlog.debug(msg)
+                return
+
+        mlog.debug('Determining dependency {!r} with pkg-config executable '
+                   '{!r}'.format(name, self.pkgbin.get_path()))
+        ret, self.version, _ = self._call_pkgbin(['--modversion', name])
+        if ret != 0:
+            return
+
+        self.is_found = True
+
+        try:
+            # Fetch cargs to be used while using this dependency
+            self._set_cargs()
+            # Fetch the libraries and library paths needed for using this
+            self._set_libs()
+        except DependencyException as e:
+            mlog.debug(f"pkg-config error with '{name}': {e}")
+            if self.required:
+                raise
+            else:
+                self.compile_args = []
+                self.link_args = []
+                self.is_found = False
+                self.reason = e
+
+    def __repr__(self):
+        s = '<{0} {1}: {2} {3}>'
+        return s.format(self.__class__.__name__, self.name, self.is_found,
+                        self.version_reqs)
+
+    def _call_pkgbin_real(self, args, env):
+        cmd = self.pkgbin.get_command() + args
+        p, out, err = Popen_safe(cmd, env=env)
+        rc, out, err = p.returncode, out.strip(), err.strip()
+        call = ' '.join(cmd)
+        mlog.debug(f"Called `{call}` -> {rc}\n{out}")
+        return rc, out, err
+
+    @staticmethod
+    def setup_env(env: T.MutableMapping[str, str], environment: 'Environment', for_machine: MachineChoice,
+                  extra_path: T.Optional[str] = None) -> None:
+        extra_paths: T.List[str] = environment.coredata.options[OptionKey('pkg_config_path', machine=for_machine)].value[:]
+        if extra_path and extra_path not in extra_paths:
+            extra_paths.append(extra_path)
+        sysroot = environment.properties[for_machine].get_sys_root()
+        if sysroot:
+            env['PKG_CONFIG_SYSROOT_DIR'] = sysroot
+        new_pkg_config_path = ':'.join([p for p in extra_paths])
+        env['PKG_CONFIG_PATH'] = new_pkg_config_path
+
+        pkg_config_libdir_prop = environment.properties[for_machine].get_pkg_config_libdir()
+        if pkg_config_libdir_prop:
+            new_pkg_config_libdir = ':'.join([p for p in pkg_config_libdir_prop])
+            env['PKG_CONFIG_LIBDIR'] = new_pkg_config_libdir
+        # Dump all PKG_CONFIG environment variables
+        for key, value in env.items():
+            if key.startswith('PKG_'):
+                mlog.debug(f'env[{key}]: {value}')
+
+    def _call_pkgbin(self, args, env=None):
+        # Always copy the environment since we're going to modify it
+        # with pkg-config variables
+        if env is None:
+            env = os.environ.copy()
+        else:
+            env = env.copy()
+
+        PkgConfigDependency.setup_env(env, self.env, self.for_machine)
+
+        fenv = frozenset(env.items())
+        targs = tuple(args)
+        cache = PkgConfigDependency.pkgbin_cache
+        if (self.pkgbin, targs, fenv) not in cache:
+            cache[(self.pkgbin, targs, fenv)] = self._call_pkgbin_real(args, env)
+        return cache[(self.pkgbin, targs, fenv)]
+
+    def _convert_mingw_paths(self, args: T.List[str]) -> T.List[str]:
+        '''
+        Both MSVC and native Python on Windows cannot handle MinGW-esque /c/foo
+        paths so convert them to C:/foo. We cannot resolve other paths starting
+        with / like /home/foo so leave them as-is so that the user gets an
+        error/warning from the compiler/linker.
+        '''
+        if not self.env.machines.build.is_windows():
+            return args
+        converted = []
+        for arg in args:
+            pargs = []
+            # Library search path
+            if arg.startswith('-L/'):
+                pargs = PurePath(arg[2:]).parts
+                tmpl = '-L{}:/{}'
+            elif arg.startswith('-I/'):
+                pargs = PurePath(arg[2:]).parts
+                tmpl = '-I{}:/{}'
+            # Full path to library or .la file
+            elif arg.startswith('/'):
+                pargs = PurePath(arg).parts
+                tmpl = '{}:/{}'
+            elif arg.startswith(('-L', '-I')) or (len(arg) > 2 and arg[1] == ':'):
+                # clean out improper '\\ ' as comes from some Windows pkg-config files
+                arg = arg.replace('\\ ', ' ')
+            if len(pargs) > 1 and len(pargs[1]) == 1:
+                arg = tmpl.format(pargs[1], '/'.join(pargs[2:]))
+            converted.append(arg)
+        return converted
+
+    def _split_args(self, cmd):
+        # pkg-config paths follow Unix conventions, even on Windows; split the
+        # output using shlex.split rather than mesonlib.split_args
+        return shlex.split(cmd)
+
+    def _set_cargs(self):
+        env = None
+        if self.language == 'fortran':
+            # gfortran doesn't appear to look in system paths for INCLUDE files,
+            # so don't allow pkg-config to suppress -I flags for system paths
+            env = os.environ.copy()
+            env['PKG_CONFIG_ALLOW_SYSTEM_CFLAGS'] = '1'
+        ret, out, err = self._call_pkgbin(['--cflags', self.name], env=env)
+        if ret != 0:
+            raise DependencyException('Could not generate cargs for %s:\n%s\n' %
+                                      (self.name, err))
+        self.compile_args = self._convert_mingw_paths(self._split_args(out))
+
+    def _search_libs(self, out, out_raw):
+        '''
+        @out: PKG_CONFIG_ALLOW_SYSTEM_LIBS=1 pkg-config --libs
+        @out_raw: pkg-config --libs
+
+        We always look for the file ourselves instead of depending on the
+        compiler to find it with -lfoo or foo.lib (if possible) because:
+        1. We want to be able to select static or shared
+        2. We need the full path of the library to calculate RPATH values
+        3. De-dup of libraries is easier when we have absolute paths
+
+        Libraries that are provided by the toolchain or are not found by
+        find_library() will be added with -L -l pairs.
+        '''
+        # Library paths should be safe to de-dup
+        #
+        # First, figure out what library paths to use. Originally, we were
+        # doing this as part of the loop, but due to differences in the order
+        # of -L values between pkg-config and pkgconf, we need to do that as
+        # a separate step. See:
+        # https://github.com/mesonbuild/meson/issues/3951
+        # https://github.com/mesonbuild/meson/issues/4023
+        #
+        # Separate system and prefix paths, and ensure that prefix paths are
+        # always searched first.
+        prefix_libpaths = OrderedSet()
+        # We also store this raw_link_args on the object later
+        raw_link_args = self._convert_mingw_paths(self._split_args(out_raw))
+        for arg in raw_link_args:
+            if arg.startswith('-L') and not arg.startswith(('-L-l', '-L-L')):
+                path = arg[2:]
+                if not os.path.isabs(path):
+                    # Resolve the path as a compiler in the build directory would
+                    path = os.path.join(self.env.get_build_dir(), path)
+                prefix_libpaths.add(path)
+        # Library paths are not always ordered in a meaningful way
+        #
+        # Instead of relying on pkg-config or pkgconf to provide -L flags in a
+        # specific order, we reorder library paths ourselves, according to th
+        # order specified in PKG_CONFIG_PATH. See:
+        # https://github.com/mesonbuild/meson/issues/4271
+        #
+        # Only prefix_libpaths are reordered here because there should not be
+        # too many system_libpaths to cause library version issues.
+        pkg_config_path: T.List[str] = self.env.coredata.options[OptionKey('pkg_config_path', machine=self.for_machine)].value
+        pkg_config_path = self._convert_mingw_paths(pkg_config_path)
+        prefix_libpaths = sort_libpaths(prefix_libpaths, pkg_config_path)
+        system_libpaths = OrderedSet()
+        full_args = self._convert_mingw_paths(self._split_args(out))
+        for arg in full_args:
+            if arg.startswith(('-L-l', '-L-L')):
+                # These are D language arguments, not library paths
+                continue
+            if arg.startswith('-L') and arg[2:] not in prefix_libpaths:
+                system_libpaths.add(arg[2:])
+        # Use this re-ordered path list for library resolution
+        libpaths = list(prefix_libpaths) + list(system_libpaths)
+        # Track -lfoo libraries to avoid duplicate work
+        libs_found = OrderedSet()
+        # Track not-found libraries to know whether to add library paths
+        libs_notfound = []
+        libtype = LibType.STATIC if self.static else LibType.PREFER_SHARED
+        # Generate link arguments for this library
+        link_args = []
+        for lib in full_args:
+            if lib.startswith(('-L-l', '-L-L')):
+                # These are D language arguments, add them as-is
+                pass
+            elif lib.startswith('-L'):
+                # We already handled library paths above
+                continue
+            elif lib.startswith('-l'):
+                # Don't resolve the same -lfoo argument again
+                if lib in libs_found:
+                    continue
+                if self.clib_compiler:
+                    args = self.clib_compiler.find_library(lib[2:], self.env,
+                                                           libpaths, libtype)
+                # If the project only uses a non-clib language such as D, Rust,
+                # C#, Python, etc, all we can do is limp along by adding the
+                # arguments as-is and then adding the libpaths at the end.
+                else:
+                    args = None
+                if args is not None:
+                    libs_found.add(lib)
+                    # Replace -l arg with full path to library if available
+                    # else, library is either to be ignored, or is provided by
+                    # the compiler, can't be resolved, and should be used as-is
+                    if args:
+                        if not args[0].startswith('-l'):
+                            lib = args[0]
+                    else:
+                        continue
+                else:
+                    # Library wasn't found, maybe we're looking in the wrong
+                    # places or the library will be provided with LDFLAGS or
+                    # LIBRARY_PATH from the environment (on macOS), and many
+                    # other edge cases that we can't account for.
+                    #
+                    # Add all -L paths and use it as -lfoo
+                    if lib in libs_notfound:
+                        continue
+                    if self.static:
+                        mlog.warning('Static library {!r} not found for dependency {!r}, may '
+                                     'not be statically linked'.format(lib[2:], self.name))
+                    libs_notfound.append(lib)
+            elif lib.endswith(".la"):
+                shared_libname = self.extract_libtool_shlib(lib)
+                shared_lib = os.path.join(os.path.dirname(lib), shared_libname)
+                if not os.path.exists(shared_lib):
+                    shared_lib = os.path.join(os.path.dirname(lib), ".libs", shared_libname)
+
+                if not os.path.exists(shared_lib):
+                    raise DependencyException('Got a libtools specific "%s" dependencies'
+                                              'but we could not compute the actual shared'
+                                              'library path' % lib)
+                self.is_libtool = True
+                lib = shared_lib
+                if lib in link_args:
+                    continue
+            link_args.append(lib)
+        # Add all -Lbar args if we have -lfoo args in link_args
+        if libs_notfound:
+            # Order of -L flags doesn't matter with ld, but it might with other
+            # linkers such as MSVC, so prepend them.
+            link_args = ['-L' + lp for lp in prefix_libpaths] + link_args
+        return link_args, raw_link_args
+
+    def _set_libs(self):
+        env = None
+        libcmd = ['--libs']
+
+        if self.static:
+            libcmd.append('--static')
+
+        libcmd.append(self.name)
+
+        # Force pkg-config to output -L fields even if they are system
+        # paths so we can do manual searching with cc.find_library() later.
+        env = os.environ.copy()
+        env['PKG_CONFIG_ALLOW_SYSTEM_LIBS'] = '1'
+        ret, out, err = self._call_pkgbin(libcmd, env=env)
+        if ret != 0:
+            raise DependencyException('Could not generate libs for %s:\n%s\n' %
+                                      (self.name, err))
+        # Also get the 'raw' output without -Lfoo system paths for adding -L
+        # args with -lfoo when a library can't be found, and also in
+        # gnome.generate_gir + gnome.gtkdoc which need -L -l arguments.
+        ret, out_raw, err_raw = self._call_pkgbin(libcmd)
+        if ret != 0:
+            raise DependencyException('Could not generate libs for %s:\n\n%s' %
+                                      (self.name, out_raw))
+        self.link_args, self.raw_link_args = self._search_libs(out, out_raw)
+
+    def get_pkgconfig_variable(self, variable_name: str, kwargs: T.Dict[str, T.Any]) -> str:
+        options = ['--variable=' + variable_name, self.name]
+
+        if 'define_variable' in kwargs:
+            definition = kwargs.get('define_variable', [])
+            if not isinstance(definition, list):
+                raise DependencyException('define_variable takes a list')
+
+            if len(definition) != 2 or not all(isinstance(i, str) for i in definition):
+                raise DependencyException('define_variable must be made up of 2 strings for VARIABLENAME and VARIABLEVALUE')
+
+            options = ['--define-variable=' + '='.join(definition)] + options
+
+        ret, out, err = self._call_pkgbin(options)
+        variable = ''
+        if ret != 0:
+            if self.required:
+                raise DependencyException('dependency %s not found:\n%s\n' %
+                                          (self.name, err))
+        else:
+            variable = out.strip()
+
+            # pkg-config doesn't distinguish between empty and non-existent variables
+            # use the variable list to check for variable existence
+            if not variable:
+                ret, out, _ = self._call_pkgbin(['--print-variables', self.name])
+                if not re.search(r'^' + variable_name + r'$', out, re.MULTILINE):
+                    if 'default' in kwargs:
+                        variable = kwargs['default']
+                    else:
+                        mlog.warning(f"pkgconfig variable '{variable_name}' not defined for dependency {self.name}.")
+
+        mlog.debug(f'Got pkgconfig variable {variable_name} : {variable}')
+        return variable
+
+    @staticmethod
+    def get_methods():
+        return [DependencyMethods.PKGCONFIG]
+
+    def check_pkgconfig(self, pkgbin):
+        if not pkgbin.found():
+            mlog.log(f'Did not find pkg-config by name {pkgbin.name!r}')
+            return None
+        try:
+            p, out = Popen_safe(pkgbin.get_command() + ['--version'])[0:2]
+            if p.returncode != 0:
+                mlog.warning('Found pkg-config {!r} but it failed when run'
+                             ''.format(' '.join(pkgbin.get_command())))
+                return None
+        except FileNotFoundError:
+            mlog.warning('We thought we found pkg-config {!r} but now it\'s not there. How odd!'
+                         ''.format(' '.join(pkgbin.get_command())))
+            return None
+        except PermissionError:
+            msg = 'Found pkg-config {!r} but didn\'t have permissions to run it.'.format(' '.join(pkgbin.get_command()))
+            if not self.env.machines.build.is_windows():
+                msg += '\n\nOn Unix-like systems this is often caused by scripts that are not executable.'
+            mlog.warning(msg)
+            return None
+        return out.strip()
+
+    def extract_field(self, la_file, fieldname):
+        with open(la_file) as f:
+            for line in f:
+                arr = line.strip().split('=')
+                if arr[0] == fieldname:
+                    return arr[1][1:-1]
+        return None
+
+    def extract_dlname_field(self, la_file):
+        return self.extract_field(la_file, 'dlname')
+
+    def extract_libdir_field(self, la_file):
+        return self.extract_field(la_file, 'libdir')
+
+    def extract_libtool_shlib(self, la_file):
+        '''
+        Returns the path to the shared library
+        corresponding to this .la file
+        '''
+        dlname = self.extract_dlname_field(la_file)
+        if dlname is None:
+            return None
+
+        # Darwin uses absolute paths where possible; since the libtool files never
+        # contain absolute paths, use the libdir field
+        if self.env.machines[self.for_machine].is_darwin():
+            dlbasename = os.path.basename(dlname)
+            libdir = self.extract_libdir_field(la_file)
+            if libdir is None:
+                return dlbasename
+            return os.path.join(libdir, dlbasename)
+        # From the comments in extract_libtool(), older libtools had
+        # a path rather than the raw dlname
+        return os.path.basename(dlname)
+
+    def log_tried(self):
+        return self.type_name
+
+    def get_variable(self, *, cmake: T.Optional[str] = None, pkgconfig: T.Optional[str] = None,
+                     configtool: T.Optional[str] = None, internal: T.Optional[str] = None,
+                     default_value: T.Optional[str] = None,
+                     pkgconfig_define: T.Optional[T.List[str]] = None) -> T.Union[str, T.List[str]]:
+        if pkgconfig:
+            kwargs = {}
+            if default_value is not None:
+                kwargs['default'] = default_value
+            if pkgconfig_define is not None:
+                kwargs['define_variable'] = pkgconfig_define
+            try:
+                return self.get_pkgconfig_variable(pkgconfig, kwargs)
+            except DependencyException:
+                pass
+        if default_value is not None:
+            return default_value
+        raise DependencyException(f'Could not get pkg-config variable and no default provided for {self!r}')