dependencies: switch the delayed-import mechanism for custom dependencies

Simply store the module it is expected to be found in. That module then
appends to the packages dict, which guarantees mypy can verify that
it's got the right type -- there is no casting needed.

14 files changed, 114 insertions, 69 deletions

diff --git a/mesonbuild/dependencies/__init__.py b/mesonbuild/dependencies/__init__.py
index 7fa1b46..c6dabc5 100644
--- a/mesonbuild/dependencies/__init__.py
+++ b/mesonbuild/dependencies/__init__.py
@@ -192,62 +192,66 @@ this approach, and no new dependencies should do this.
 # - An ExternalDependency subclass
 # - A DependencyFactory object
 # - A callable with a signature of (Environment, MachineChoice, Dict[str, Any]) -> List[Callable[[], ExternalDependency]]
+#
+# The internal "defaults" attribute contains a separate dictionary mapping
+# for lazy imports. The values must be:
+# - a string naming the submodule that should be imported from `mesonbuild.dependencies` to populate the dependency
 packages.defaults.update({
     # From dev:
-    'gtest': 'dev:gtest_factory',
-    'gmock': 'dev:gmock_factory',
-    'llvm': 'dev:llvm_factory',
-    'valgrind': 'dev:ValgrindDependency',
-    'zlib': 'dev:zlib_factory',
-    'jni': 'dev:JNISystemDependency',
-    'jdk': 'dev:JDKSystemDependency',
+    'gtest': 'dev',
+    'gmock': 'dev',
+    'llvm': 'dev',
+    'valgrind': 'dev',
+    'zlib': 'dev',
+    'jni': 'dev',
+    'jdk': 'dev',
 
-    'boost': 'boost:BoostDependency',
-    'cuda': 'cuda:CudaDependency',
+    'boost': 'boost',
+    'cuda': 'cuda',
 
     # per-file
-    'coarray': 'coarrays:coarray_factory',
-    'hdf5': 'hdf5:hdf5_factory',
-    'mpi': 'mpi:mpi_factory',
-    'scalapack': 'scalapack:scalapack_factory',
+    'coarray': 'coarrays',
+    'hdf5': 'hdf5',
+    'mpi': 'mpi',
+    'scalapack': 'scalapack',
 
     # From misc:
-    'blocks': 'misc:BlocksDependency',
-    'curses': 'misc:curses_factory',
-    'netcdf': 'misc:netcdf_factory',
-    'openmp': 'misc:OpenMPDependency',
-    'threads': 'misc:threads_factory',
-    'pcap': 'misc:pcap_factory',
-    'cups': 'misc:cups_factory',
-    'libwmf': 'misc:libwmf_factory',
-    'libgcrypt': 'misc:libgcrypt_factory',
-    'gpgme': 'misc:gpgme_factory',
-    'shaderc': 'misc:shaderc_factory',
-    'iconv': 'misc:iconv_factory',
-    'intl': 'misc:intl_factory',
-    'dl': 'misc:dl_factory',
-    'openssl': 'misc:openssl_factory',
-    'libcrypto': 'misc:libcrypto_factory',
-    'libssl': 'misc:libssl_factory',
+    'blocks': 'misc',
+    'curses': 'misc',
+    'netcdf': 'misc',
+    'openmp': 'misc',
+    'threads': 'misc',
+    'pcap': 'misc',
+    'cups': 'misc',
+    'libwmf': 'misc',
+    'libgcrypt': 'misc',
+    'gpgme': 'misc',
+    'shaderc': 'misc',
+    'iconv': 'misc',
+    'intl': 'misc',
+    'dl': 'misc',
+    'openssl': 'misc',
+    'libcrypto': 'misc',
+    'libssl': 'misc',
 
     # From platform:
-    'appleframeworks': 'platform:AppleFrameworks',
+    'appleframeworks': 'platform',
 
     # from python:
-    'python3': 'python:python_factory',
-    'pybind11': 'python:pybind11_factory',
+    'python3': 'python',
+    'pybind11': 'python',
 
     # From ui:
-    'gl': 'ui:gl_factory',
-    'gnustep': 'ui:GnuStepDependency',
-    'sdl2': 'ui:sdl2_factory',
-    'wxwidgets': 'ui:WxDependency',
-    'vulkan': 'ui:vulkan_factory',
+    'gl': 'ui',
+    'gnustep': 'ui',
+    'sdl2': 'ui',
+    'wxwidgets': 'ui',
+    'vulkan': 'ui',
 
     # from qt
-    'qt4': 'qt:qt4_factory',
-    'qt5': 'qt:qt5_factory',
-    'qt6': 'qt:qt6_factory',
+    'qt4': 'qt',
+    'qt5': 'qt',
+    'qt6': 'qt',
 })
 _packages_accept_language.update({
     'hdf5',
diff --git a/mesonbuild/dependencies/boost.py b/mesonbuild/dependencies/boost.py
index 44f1baf..0e4dab9 100644
--- a/mesonbuild/dependencies/boost.py
+++ b/mesonbuild/dependencies/boost.py
@@ -23,6 +23,7 @@ from .. import mlog
 from .. import mesonlib
 
 from .base import DependencyException, SystemDependency
+from .detect import packages
 from .pkgconfig import PkgConfigDependency
 from .misc import threads_factory
 
@@ -738,6 +739,7 @@ class BoostDependency(SystemDependency):
         # BOOST_ALL_DYN_LINK should not be required with the known defines below
         return ['-DBOOST_ALL_NO_LIB']  # Disable automatic linking
 
+packages['boost'] = BoostDependency
 
 # See https://www.boost.org/doc/libs/1_72_0/more/getting_started/unix-variants.html#library-naming
 # See https://mesonbuild.com/Reference-tables.html#cpu-families
diff --git a/mesonbuild/dependencies/coarrays.py b/mesonbuild/dependencies/coarrays.py
index 70cf4f8..5cb8556 100644
--- a/mesonbuild/dependencies/coarrays.py
+++ b/mesonbuild/dependencies/coarrays.py
@@ -18,6 +18,7 @@ import typing as T
 
 from .base import DependencyMethods, detect_compiler, SystemDependency
 from .cmake import CMakeDependency
+from .detect import packages
 from .pkgconfig import PkgConfigDependency
 from .factory import factory_methods
 
@@ -51,6 +52,7 @@ def coarray_factory(env: 'Environment',
         candidates.append(functools.partial(CoarrayDependency, env, kwargs))
 
     return candidates
+packages['coarray'] = coarray_factory
 
 
 class CoarrayDependency(SystemDependency):
diff --git a/mesonbuild/dependencies/cuda.py b/mesonbuild/dependencies/cuda.py
index 89e562f..af0ae4b 100644
--- a/mesonbuild/dependencies/cuda.py
+++ b/mesonbuild/dependencies/cuda.py
@@ -23,6 +23,7 @@ from .. import mesonlib
 from .. import mlog
 from ..environment import detect_cpu_family
 from .base import DependencyException, SystemDependency
+from .detect import packages
 
 
 if T.TYPE_CHECKING:
@@ -290,3 +291,5 @@ class CudaDependency(SystemDependency):
         for lib in self.requested_modules:
             args += self.lib_modules[lib]
         return args
+
+packages['cuda'] = CudaDependency
diff --git a/mesonbuild/dependencies/detect.py b/mesonbuild/dependencies/detect.py
index a10131d..9428d54 100644
--- a/mesonbuild/dependencies/detect.py
+++ b/mesonbuild/dependencies/detect.py
@@ -35,12 +35,10 @@ class DependencyPackages(collections.UserDict):
 
     def __missing__(self, key: str) -> PackageTypes:
         if key in self.defaults:
-            modn, package = self.defaults[key].split(':', maxsplit=1)
-            mod = importlib.import_module(f'mesonbuild.dependencies.{modn}')
-            value = T.cast('PackageTypes', getattr(mod, package))
-            self.data[key] = value
+            modn = self.defaults[key]
+            importlib.import_module(f'mesonbuild.dependencies.{modn}')
 
-            return value
+            return self.data[key]
         raise KeyError(key)
 
     def __contains__(self, key: object) -> bool:
diff --git a/mesonbuild/dependencies/dev.py b/mesonbuild/dependencies/dev.py
index 9c03496..ec70151 100644
--- a/mesonbuild/dependencies/dev.py
+++ b/mesonbuild/dependencies/dev.py
@@ -34,6 +34,7 @@ from ..mesonlib import version_compare, version_compare_many, search_version, st
 from .base import DependencyException, DependencyMethods, detect_compiler, strip_system_includedirs, strip_system_libdirs, SystemDependency, ExternalDependency, DependencyTypeName
 from .cmake import CMakeDependency
 from .configtool import ConfigToolDependency
+from .detect import packages
 from .factory import DependencyFactory
 from .misc import threads_factory
 from .pkgconfig import PkgConfigDependency
@@ -507,6 +508,8 @@ class ValgrindDependency(PkgConfigDependency):
     def get_link_args(self, language: T.Optional[str] = None, raw: bool = False) -> T.List[str]:
         return []
 
+packages['valgrind'] = ValgrindDependency
+
 
 class ZlibSystemDependency(SystemDependency):
 
@@ -671,6 +674,8 @@ class JNISystemDependency(SystemDependency):
 
         return None
 
+packages['jni'] = JNISystemDependency
+
 
 class JDKSystemDependency(JNISystemDependency):
     def __init__(self, environment: 'Environment', kwargs: JNISystemDependencyKW):
@@ -683,29 +688,31 @@ class JDKSystemDependency(JNISystemDependency):
             'Use the jni system dependency instead'
         ))
 
+packages['jdk'] = JDKSystemDependency
+
 
-llvm_factory = DependencyFactory(
+packages['llvm'] = llvm_factory = DependencyFactory(
     'LLVM',
     [DependencyMethods.CMAKE, DependencyMethods.CONFIG_TOOL],
     cmake_class=LLVMDependencyCMake,
     configtool_class=LLVMDependencyConfigTool,
 )
 
-gtest_factory = DependencyFactory(
+packages['gtest'] = gtest_factory = DependencyFactory(
     'gtest',
     [DependencyMethods.PKGCONFIG, DependencyMethods.SYSTEM],
     pkgconfig_class=GTestDependencyPC,
     system_class=GTestDependencySystem,
 )
 
-gmock_factory = DependencyFactory(
+packages['gmock'] = gmock_factory = DependencyFactory(
     'gmock',
     [DependencyMethods.PKGCONFIG, DependencyMethods.SYSTEM],
     pkgconfig_class=GMockDependencyPC,
     system_class=GMockDependencySystem,
 )
 
-zlib_factory = DependencyFactory(
+packages['zlib'] = zlib_factory = DependencyFactory(
     'zlib',
     [DependencyMethods.PKGCONFIG, DependencyMethods.CMAKE, DependencyMethods.SYSTEM],
     cmake_name='ZLIB',
diff --git a/mesonbuild/dependencies/hdf5.py b/mesonbuild/dependencies/hdf5.py
index 4e5820a..392bb09 100644
--- a/mesonbuild/dependencies/hdf5.py
+++ b/mesonbuild/dependencies/hdf5.py
@@ -25,6 +25,7 @@ from ..mesonlib import Popen_safe, OrderedSet, join_args
 from ..programs import ExternalProgram
 from .base import DependencyException, DependencyMethods
 from .configtool import ConfigToolDependency
+from .detect import packages
 from .pkgconfig import PkgConfigDependency
 from .factory import factory_methods
 import typing as T
@@ -178,3 +179,5 @@ def hdf5_factory(env: 'Environment', for_machine: 'MachineChoice',
         candidates.append(functools.partial(HDF5ConfigToolDependency, 'hdf5', env, kwargs, language))
 
     return candidates
+
+packages['hdf5'] = hdf5_factory
diff --git a/mesonbuild/dependencies/misc.py b/mesonbuild/dependencies/misc.py
index 0c747c4..d775669 100644
--- a/mesonbuild/dependencies/misc.py
+++ b/mesonbuild/dependencies/misc.py
@@ -25,6 +25,7 @@ from .base import DependencyException, DependencyMethods
 from .base import BuiltinDependency, SystemDependency
 from .cmake import CMakeDependency
 from .configtool import ConfigToolDependency
+from .detect import packages
 from .factory import DependencyFactory, factory_methods
 from .pkgconfig import PkgConfigDependency
 
@@ -57,6 +58,8 @@ def netcdf_factory(env: 'Environment',
 
     return candidates
 
+packages['netcdf'] = netcdf_factory
+
 
 class DlBuiltinDependency(BuiltinDependency):
     def __init__(self, name: str, env: 'Environment', kwargs: T.Dict[str, T.Any]):
@@ -136,6 +139,8 @@ class OpenMPDependency(SystemDependency):
             if not self.is_found:
                 mlog.log(mlog.yellow('WARNING:'), 'OpenMP found but omp.h missing.')
 
+packages['openmp'] = OpenMPDependency
+
 
 class ThreadDependency(SystemDependency):
     def __init__(self, name: str, environment: 'Environment', kwargs: T.Dict[str, T.Any]) -> None:
@@ -183,6 +188,8 @@ class BlocksDependency(SystemDependency):
 
             self.is_found = True
 
+packages['blocks'] = BlocksDependency
+
 
 class PcapDependencyConfigTool(ConfigToolDependency):
 
@@ -489,6 +496,7 @@ def curses_factory(env: 'Environment',
             candidates.append(functools.partial(CursesSystemDependency, 'curses', env, kwargs))
 
     return candidates
+packages['curses'] = curses_factory
 
 
 @factory_methods({DependencyMethods.PKGCONFIG, DependencyMethods.SYSTEM})
@@ -524,83 +532,84 @@ def shaderc_factory(env: 'Environment',
         candidates.append(functools.partial(ShadercDependency, env, kwargs))
 
     return candidates
+packages['shaderc'] = shaderc_factory
 
 
-cups_factory = DependencyFactory(
+packages['cups'] = cups_factory = DependencyFactory(
     'cups',
     [DependencyMethods.PKGCONFIG, DependencyMethods.CONFIG_TOOL, DependencyMethods.EXTRAFRAMEWORK, DependencyMethods.CMAKE],
     configtool_class=CupsDependencyConfigTool,
     cmake_name='Cups',
 )
 
-dl_factory = DependencyFactory(
+packages['dl'] = dl_factory = DependencyFactory(
     'dl',
     [DependencyMethods.BUILTIN, DependencyMethods.SYSTEM],
     builtin_class=DlBuiltinDependency,
     system_class=DlSystemDependency,
 )
 
-gpgme_factory = DependencyFactory(
+packages['gpgme'] = gpgme_factory = DependencyFactory(
     'gpgme',
     [DependencyMethods.PKGCONFIG, DependencyMethods.CONFIG_TOOL],
     configtool_class=GpgmeDependencyConfigTool,
 )
 
-libgcrypt_factory = DependencyFactory(
+packages['libgcrypt'] = libgcrypt_factory = DependencyFactory(
     'libgcrypt',
     [DependencyMethods.PKGCONFIG, DependencyMethods.CONFIG_TOOL],
     configtool_class=LibGCryptDependencyConfigTool,
 )
 
-libwmf_factory = DependencyFactory(
+packages['libwmf'] = libwmf_factory = DependencyFactory(
     'libwmf',
     [DependencyMethods.PKGCONFIG, DependencyMethods.CONFIG_TOOL],
     configtool_class=LibWmfDependencyConfigTool,
 )
 
-pcap_factory = DependencyFactory(
+packages['pcap'] = pcap_factory = DependencyFactory(
     'pcap',
     [DependencyMethods.PKGCONFIG, DependencyMethods.CONFIG_TOOL],
     configtool_class=PcapDependencyConfigTool,
     pkgconfig_name='libpcap',
 )
 
-threads_factory = DependencyFactory(
+packages['threads'] = threads_factory = DependencyFactory(
     'threads',
     [DependencyMethods.SYSTEM, DependencyMethods.CMAKE],
     cmake_name='Threads',
     system_class=ThreadDependency,
 )
 
-iconv_factory = DependencyFactory(
+packages['iconv'] = iconv_factory = DependencyFactory(
     'iconv',
     [DependencyMethods.BUILTIN, DependencyMethods.SYSTEM],
     builtin_class=IconvBuiltinDependency,
     system_class=IconvSystemDependency,
 )
 
-intl_factory = DependencyFactory(
+packages['intl'] = intl_factory = DependencyFactory(
     'intl',
     [DependencyMethods.BUILTIN, DependencyMethods.SYSTEM],
     builtin_class=IntlBuiltinDependency,
     system_class=IntlSystemDependency,
 )
 
-openssl_factory = DependencyFactory(
+packages['openssl'] = openssl_factory = DependencyFactory(
     'openssl',
     [DependencyMethods.PKGCONFIG, DependencyMethods.SYSTEM, DependencyMethods.CMAKE],
     system_class=OpensslSystemDependency,
     cmake_class=lambda name, env, kwargs: CMakeDependency('OpenSSL', env, dict(kwargs, modules=['OpenSSL::Crypto', 'OpenSSL::SSL'])),
 )
 
-libcrypto_factory = DependencyFactory(
+packages['libcrypto'] = libcrypto_factory = DependencyFactory(
     'libcrypto',
     [DependencyMethods.PKGCONFIG, DependencyMethods.SYSTEM, DependencyMethods.CMAKE],
     system_class=OpensslSystemDependency,
     cmake_class=lambda name, env, kwargs: CMakeDependency('OpenSSL', env, dict(kwargs, modules=['OpenSSL::Crypto'])),
 )
 
-libssl_factory = DependencyFactory(
+packages['libssl'] = libssl_factory = DependencyFactory(
     'libssl',
     [DependencyMethods.PKGCONFIG, DependencyMethods.SYSTEM, DependencyMethods.CMAKE],
     system_class=OpensslSystemDependency,
diff --git a/mesonbuild/dependencies/mpi.py b/mesonbuild/dependencies/mpi.py
index 8f83ce4..9100681 100644
--- a/mesonbuild/dependencies/mpi.py
+++ b/mesonbuild/dependencies/mpi.py
@@ -21,6 +21,7 @@ import re
 from ..environment import detect_cpu_family
 from .base import DependencyMethods, detect_compiler, SystemDependency
 from .configtool import ConfigToolDependency
+from .detect import packages
 from .factory import factory_methods
 from .pkgconfig import PkgConfigDependency
 
@@ -100,6 +101,8 @@ def mpi_factory(env: 'Environment',
 
     return candidates
 
+packages['mpi'] = mpi_factory
+
 
 class _MPIConfigToolDependency(ConfigToolDependency):
 
diff --git a/mesonbuild/dependencies/platform.py b/mesonbuild/dependencies/platform.py
index 6d32555..87726b5 100644
--- a/mesonbuild/dependencies/platform.py
+++ b/mesonbuild/dependencies/platform.py
@@ -17,6 +17,7 @@
 from __future__ import annotations
 
 from .base import DependencyTypeName, ExternalDependency, DependencyException
+from .detect import packages
 from ..mesonlib import MesonException
 import typing as T
 
@@ -58,3 +59,5 @@ class AppleFrameworks(ExternalDependency):
     @staticmethod
     def log_tried() -> str:
         return 'framework'
+
+packages['appleframeworks'] = AppleFrameworks
diff --git a/mesonbuild/dependencies/python.py b/mesonbuild/dependencies/python.py
index 2410007..1607728 100644
--- a/mesonbuild/dependencies/python.py
+++ b/mesonbuild/dependencies/python.py
@@ -20,6 +20,7 @@ import typing as T
 from .. import mesonlib, mlog
 from .base import process_method_kw, DependencyMethods, DependencyTypeName, ExternalDependency, SystemDependency
 from .configtool import ConfigToolDependency
+from .detect import packages
 from .factory import DependencyFactory
 from .framework import ExtraFrameworkDependency
 from .pkgconfig import PkgConfigDependency
@@ -407,7 +408,9 @@ def python_factory(env: 'Environment', for_machine: 'MachineChoice',
 
     return candidates
 
-pybind11_factory = DependencyFactory(
+packages['python3'] = python_factory
+
+packages['pybind11'] = pybind11_factory = DependencyFactory(
     'pybind11',
     [DependencyMethods.PKGCONFIG, DependencyMethods.CONFIG_TOOL, DependencyMethods.CMAKE],
     configtool_class=Pybind11ConfigToolDependency,
diff --git a/mesonbuild/dependencies/qt.py b/mesonbuild/dependencies/qt.py
index 6d31859..1a86bd2 100644
--- a/mesonbuild/dependencies/qt.py
+++ b/mesonbuild/dependencies/qt.py
@@ -24,6 +24,7 @@ import typing as T
 
 from .base import DependencyException, DependencyMethods
 from .configtool import ConfigToolDependency
+from .detect import packages
 from .framework import ExtraFrameworkDependency
 from .pkgconfig import PkgConfigDependency
 from .factory import DependencyFactory
@@ -467,21 +468,21 @@ class Qt6PkgConfigDependency(Qt6WinMainMixin, QtPkgConfigDependency):
         return _qt_get_private_includes(mod_inc_dir, module, self.version)
 
 
-qt4_factory = DependencyFactory(
+packages['qt4'] = qt4_factory = DependencyFactory(
     'qt4',
     [DependencyMethods.PKGCONFIG, DependencyMethods.CONFIG_TOOL],
     pkgconfig_class=Qt4PkgConfigDependency,
     configtool_class=Qt4ConfigToolDependency,
 )
 
-qt5_factory = DependencyFactory(
+packages['qt5'] = qt5_factory = DependencyFactory(
     'qt5',
     [DependencyMethods.PKGCONFIG, DependencyMethods.CONFIG_TOOL],
     pkgconfig_class=Qt5PkgConfigDependency,
     configtool_class=Qt5ConfigToolDependency,
 )
 
-qt6_factory = DependencyFactory(
+packages['qt6'] = qt6_factory = DependencyFactory(
     'qt6',
     [DependencyMethods.PKGCONFIG, DependencyMethods.CONFIG_TOOL],
     pkgconfig_class=Qt6PkgConfigDependency,
diff --git a/mesonbuild/dependencies/scalapack.py b/mesonbuild/dependencies/scalapack.py
index be8ee70..257e4aa 100644
--- a/mesonbuild/dependencies/scalapack.py
+++ b/mesonbuild/dependencies/scalapack.py
@@ -22,6 +22,7 @@ from ..mesonlib import OptionKey
 from .base import DependencyMethods
 from .base import DependencyException
 from .cmake import CMakeDependency
+from .detect import packages
 from .pkgconfig import PkgConfigDependency
 from .factory import factory_methods
 
@@ -52,6 +53,8 @@ def scalapack_factory(env: 'Environment', for_machine: 'MachineChoice',
 
     return candidates
 
+packages['scalapack'] = scalapack_factory
+
 
 class MKLPkgConfigDependency(PkgConfigDependency):
 
diff --git a/mesonbuild/dependencies/ui.py b/mesonbuild/dependencies/ui.py
index f3879be..1dffa1f 100644
--- a/mesonbuild/dependencies/ui.py
+++ b/mesonbuild/dependencies/ui.py
@@ -29,6 +29,7 @@ from ..environment import detect_cpu_family
 
 from .base import DependencyException, DependencyMethods, DependencyTypeName, SystemDependency
 from .configtool import ConfigToolDependency
+from .detect import packages
 from .factory import DependencyFactory
 
 if T.TYPE_CHECKING:
@@ -136,6 +137,8 @@ class GnuStepDependency(ConfigToolDependency):
             version = '1'
         return version
 
+packages['gnustep'] = GnuStepDependency
+
 
 class SDL2DependencyConfigTool(ConfigToolDependency):
 
@@ -187,6 +190,7 @@ class WxDependency(ConfigToolDependency):
                 raise DependencyException('wxwidgets module argument is not a string')
         return candidates
 
+packages['wxwidgets'] = WxDependency
 
 class VulkanDependencySystem(SystemDependency):
 
@@ -244,20 +248,20 @@ class VulkanDependencySystem(SystemDependency):
                     self.link_args.append(lib)
                 return
 
-gl_factory = DependencyFactory(
+packages['gl'] = gl_factory = DependencyFactory(
     'gl',
     [DependencyMethods.PKGCONFIG, DependencyMethods.SYSTEM],
     system_class=GLDependencySystem,
 )
 
-sdl2_factory = DependencyFactory(
+packages['sdl2'] = sdl2_factory = DependencyFactory(
     'sdl2',
     [DependencyMethods.PKGCONFIG, DependencyMethods.CONFIG_TOOL, DependencyMethods.EXTRAFRAMEWORK, DependencyMethods.CMAKE],
     configtool_class=SDL2DependencyConfigTool,
     cmake_name='SDL2',
 )
 
-vulkan_factory = DependencyFactory(
+packages['vulkan'] = vulkan_factory = DependencyFactory(
     'vulkan',
     [DependencyMethods.PKGCONFIG, DependencyMethods.SYSTEM],
     system_class=VulkanDependencySystem,