holders: remove unholder

11 files changed, 85 insertions, 88 deletions

diff --git a/mesonbuild/modules/__init__.py b/mesonbuild/modules/__init__.py
index 69bb552..2b53de5 100644
--- a/mesonbuild/modules/__init__.py
+++ b/mesonbuild/modules/__init__.py
@@ -18,13 +18,12 @@
 import os
 
 from .. import build
-from ..mesonlib import unholder, relpath
+from ..mesonlib import relpath, HoldableObject
 import typing as T
 
 if T.TYPE_CHECKING:
     from ..interpreter import Interpreter
-    from ..interpreter.interpreterobjects import IncludeDirsHolder, ExternalProgramHolder
-    from ..interpreterbase import TYPE_var, TYPE_nvar, TYPE_nkwargs
+    from ..interpreterbase import TYPE_var, TYPE_kwargs
     from ..programs import ExternalProgram
 
 class ModuleState:
@@ -61,7 +60,7 @@ class ModuleState:
         self.target_machine = interpreter.builtin['target_machine'].held_object
         self.current_node = interpreter.current_node
 
-    def get_include_args(self, include_dirs: T.Iterable[T.Union[str, 'IncludeDirsHolder']], prefix: str = '-I') -> T.List[str]:
+    def get_include_args(self, include_dirs: T.Iterable[T.Union[str, build.IncludeDirs]], prefix: str = '-I') -> T.List[str]:
         if not include_dirs:
             return []
 
@@ -69,7 +68,7 @@ class ModuleState:
         builddir = self.environment.get_build_dir()
 
         dirs_str: T.List[str] = []
-        for dirs in unholder(include_dirs):
+        for dirs in include_dirs:
             if isinstance(dirs, str):
                 dirs_str += [f'{prefix}{dirs}']
                 continue
@@ -89,14 +88,17 @@ class ModuleState:
 
     def find_program(self, prog: T.Union[str, T.List[str]], required: bool = True,
                      version_func: T.Optional[T.Callable[['ExternalProgram'], str]] = None,
-                     wanted: T.Optional[str] = None) -> 'ExternalProgramHolder':
+                     wanted: T.Optional[str] = None) -> 'ExternalProgram':
         return self._interpreter.find_program_impl(prog, required=required, version_func=version_func, wanted=wanted)
 
-class ModuleObject:
+class ModuleObject(HoldableObject):
     """Base class for all objects returned by modules
     """
     def __init__(self) -> None:
-        self.methods = {}  # type: T.Dict[str, T.Callable[[ModuleState, T.List[TYPE_nvar], TYPE_nkwargs], T.Union[ModuleReturnValue, TYPE_var]]]
+        self.methods: T.Dict[
+            str,
+            T.Callable[[ModuleState, T.List[TYPE_var], TYPE_kwargs], T.Union[ModuleReturnValue, TYPE_var]]
+        ] = {}
 
 class MutableModuleObject(ModuleObject):
     pass
diff --git a/mesonbuild/modules/cmake.py b/mesonbuild/modules/cmake.py
index fac3b24..cb37edc 100644
--- a/mesonbuild/modules/cmake.py
+++ b/mesonbuild/modules/cmake.py
@@ -18,9 +18,9 @@ import typing as T
 
 from . import ExtensionModule, ModuleReturnValue, ModuleObject
 
-from .. import build, mesonlib, mlog
+from .. import build, mesonlib, mlog, dependencies
 from ..cmake import SingleTargetOptions, TargetOptions, cmake_defines_to_args
-from ..interpreter import ConfigurationDataHolder, SubprojectHolder, DependencyHolder
+from ..interpreter import ConfigurationDataObject, SubprojectHolder
 from ..interpreterbase import (
     FeatureNew,
     FeatureNewKwargs,
@@ -32,6 +32,7 @@ from ..interpreterbase import (
     noKwargs,
 
     InvalidArguments,
+    InterpreterException,
 )
 from ..programs import ExternalProgram
 
@@ -109,11 +110,11 @@ class CMakeSubproject(ModuleObject):
     def dependency(self, state, args, kwargs):
         info = self._args_to_info(args)
         orig = self.get_variable(state, [info['dep']], {})
-        assert isinstance(orig, DependencyHolder)
-        actual = orig.include_type_method([], {})
+        assert isinstance(orig, dependencies.Dependency)
+        actual = orig.include_type
         if 'include_type' in kwargs and kwargs['include_type'] != actual:
             mlog.debug('Current include type is {}. Converting to requested {}'.format(actual, kwargs['include_type']))
-            return orig.as_system_method([kwargs['include_type']], {})
+            return orig.generate_system_dependency(kwargs['include_type'])
         return orig
 
     @noKwargs
@@ -351,7 +352,7 @@ class CmakeModule(ExtensionModule):
         if 'configuration' not in kwargs:
             raise mesonlib.MesonException('"configuration" not specified.')
         conf = kwargs['configuration']
-        if not isinstance(conf, ConfigurationDataHolder):
+        if not isinstance(conf, ConfigurationDataObject):
             raise mesonlib.MesonException('Argument "configuration" is not of type configuration_data')
 
         prefix = state.environment.coredata.get_option(mesonlib.OptionKey('prefix'))
@@ -365,7 +366,7 @@ class CmakeModule(ExtensionModule):
             extra = PACKAGE_INIT_EXT.replace('@absInstallDir@', abs_install_dir)
             extra = extra.replace('@installPrefix@', prefix)
 
-        self.create_package_file(ifile_abs, ofile_abs, PACKAGE_RELATIVE_PATH, extra, conf.held_object)
+        self.create_package_file(ifile_abs, ofile_abs, PACKAGE_RELATIVE_PATH, extra, conf.conf_data)
         conf.mark_used()
 
         conffile = os.path.normpath(inputfile.relative_name())
@@ -389,7 +390,7 @@ class CmakeModule(ExtensionModule):
             raise InterpreterException('"options" cannot be used together with "cmake_options"')
         dirname = args[0]
         subp = self.interpreter.do_subproject(dirname, 'cmake', kwargs)
-        if not subp.held_object:
+        if not subp.found():
             return subp
         return CMakeSubproject(subp, dirname)
 
diff --git a/mesonbuild/modules/gnome.py b/mesonbuild/modules/gnome.py
index 0a72ad6..0ae1c70 100644
--- a/mesonbuild/modules/gnome.py
+++ b/mesonbuild/modules/gnome.py
@@ -30,7 +30,7 @@ from . import ExtensionModule
 from . import ModuleReturnValue
 from ..mesonlib import (
     MachineChoice, MesonException, OrderedSet, Popen_safe, extract_as_list,
-    join_args, unholder,
+    join_args, HoldableObject
 )
 from ..dependencies import Dependency, PkgConfigDependency, InternalDependency
 from ..interpreterbase import noPosargs, noKwargs, permittedKwargs, FeatureNew, FeatureNewKwargs, FeatureDeprecatedKwargs
@@ -39,6 +39,7 @@ from ..build import CustomTarget, CustomTargetIndex, GeneratedList
 
 if T.TYPE_CHECKING:
     from ..compilers import Compiler
+    from ..interpreter import Interpreter
 
 # gresource compilation is broken due to the way
 # the resource compiler and Ninja clash about it
@@ -103,14 +104,13 @@ class GnomeModule(ExtensionModule):
 
     def _get_dep(self, state, depname, native=False, required=True):
         kwargs = {'native': native, 'required': required}
-        holder = self.interpreter.func_dependency(state.current_node, [depname], kwargs)
-        return holder.held_object
+        return self.interpreter.func_dependency(state.current_node, [depname], kwargs)
 
     def _get_native_binary(self, state, name, depname, varname, required=True):
         # Look in overrides in case glib/gtk/etc are built as subproject
         prog = self.interpreter.program_from_overrides([name], [])
         if prog is not None:
-            return unholder(prog)
+            return prog
 
         # Look in machine file
         prog = state.environment.lookup_binary_entry(MachineChoice.HOST, name)
@@ -125,7 +125,7 @@ class GnomeModule(ExtensionModule):
                 return ExternalProgram(name, value)
 
         # Normal program lookup
-        return unholder(state.find_program(name, required=required))
+        return state.find_program(name, required=required)
 
     @permittedKwargs({'glib_compile_schemas', 'gio_querymodules', 'gtk_update_icon_cache'})
     @noPosargs
@@ -179,7 +179,7 @@ class GnomeModule(ExtensionModule):
         # Validate dependencies
         subdirs = []
         depends = []
-        for (ii, dep) in enumerate(unholder(dependencies)):
+        for (ii, dep) in enumerate(dependencies):
             if isinstance(dep, mesonlib.File):
                 subdirs.append(dep.subdir)
             elif isinstance(dep, (build.CustomTarget, build.CustomTargetIndex)):
@@ -323,7 +323,7 @@ class GnomeModule(ExtensionModule):
         subdirs = []
         for resfile in dep_files[:]:
             resbasename = os.path.basename(resfile)
-            for dep in unholder(dependencies):
+            for dep in dependencies:
                 if isinstance(dep, mesonlib.File):
                     if dep.fname != resbasename:
                         continue
@@ -399,7 +399,7 @@ class GnomeModule(ExtensionModule):
         # require two args in order, such as -framework AVFoundation
         external_ldflags_nodedup = []
         gi_includes = OrderedSet()
-        deps = mesonlib.unholder(mesonlib.listify(deps))
+        deps = mesonlib.listify(deps)
 
         for dep in deps:
             if isinstance(dep, Dependency):
@@ -409,7 +409,7 @@ class GnomeModule(ExtensionModule):
             if isinstance(dep, InternalDependency):
                 cflags.update(dep.get_compile_args())
                 cflags.update(state.get_include_args(dep.include_directories))
-                for lib in unholder(dep.libraries):
+                for lib in dep.libraries:
                     if isinstance(lib, build.SharedLibrary):
                         internal_ldflags.update(self._get_link_args(state, lib, depends, include_rpath))
                         libdepflags = self._get_dependencies_flags(lib.get_external_deps(), state, depends, include_rpath,
@@ -426,7 +426,7 @@ class GnomeModule(ExtensionModule):
                 external_ldflags.update(extdepflags[2])
                 external_ldflags_nodedup += extdepflags[3]
                 gi_includes.update(extdepflags[4])
-                for source in unholder(dep.sources):
+                for source in dep.sources:
                     if isinstance(source, GirTarget):
                         gi_includes.update([os.path.join(state.environment.get_build_dir(),
                                             source.get_subdir())])
@@ -480,9 +480,6 @@ class GnomeModule(ExtensionModule):
             return cflags, internal_ldflags, external_ldflags, external_ldflags_nodedup, gi_includes
 
     def _unwrap_gir_target(self, girtarget, state):
-        while hasattr(girtarget, 'held_object'):
-            girtarget = girtarget.held_object
-
         if not isinstance(girtarget, (build.Executable, build.SharedLibrary,
                                       build.StaticLibrary)):
             raise MesonException('Gir target must be an executable or library')
@@ -512,8 +509,6 @@ class GnomeModule(ExtensionModule):
     @functools.lru_cache(maxsize=None)
     def _gir_has_option(self, option) -> bool:
         exe = self.giscanner
-        if hasattr(exe, 'held_object'):
-            exe = exe.held_object
         if isinstance(exe, OverrideProgram):
             # Handle overridden g-ir-scanner
             assert option in ['--extra-library', '--sources-top-dirs']
@@ -539,7 +534,7 @@ class GnomeModule(ExtensionModule):
             link_with = mesonlib.extract_as_list(kwargs, 'link_with', pop = True)
 
             for link in link_with:
-                ret += self._get_link_args(state, link.held_object, depends,
+                ret += self._get_link_args(state, link, depends,
                                            use_gir_args=True)
         return ret
 
@@ -549,7 +544,7 @@ class GnomeModule(ExtensionModule):
 
         if 'includes' in kwargs:
             includes = mesonlib.extract_as_list(kwargs, 'includes', pop = True)
-            for inc in unholder(includes):
+            for inc in includes:
                 if isinstance(inc, str):
                     ret += [f'--include={inc}']
                 elif isinstance(inc, GirTarget):
@@ -605,7 +600,7 @@ class GnomeModule(ExtensionModule):
     def _scan_inc_dirs(self, kwargs):
         ret = mesonlib.extract_as_list(kwargs, 'include_directories', pop = True)
         for incd in ret:
-            if not isinstance(incd.held_object, (str, build.IncludeDirs)):
+            if not isinstance(incd, (str, build.IncludeDirs)):
                 raise MesonException(
                     'Gir include dirs should be include_directories().')
         return ret
@@ -708,7 +703,7 @@ class GnomeModule(ExtensionModule):
         gir_filelist_filename = os.path.join(gir_filelist_dir, f'{ns}_{nsversion}_gir_filelist')
 
         with open(gir_filelist_filename, 'w', encoding='utf-8') as gir_filelist:
-            for s in unholder(libsources):
+            for s in libsources:
                 if isinstance(s, (build.CustomTarget, build.CustomTargetIndex)):
                     for custom_output in s.get_outputs():
                         gir_filelist.write(os.path.join(state.environment.get_build_dir(),
@@ -763,11 +758,11 @@ class GnomeModule(ExtensionModule):
         # dependencies and also find the include directories needed for the
         # typelib generation custom target below.
         typelib_includes = []
-        for dep in unholder(deps):
+        for dep in deps:
             # Add a dependency on each GirTarget listed in dependencies and add
             # the directory where it will be generated to the typelib includes
             if isinstance(dep, InternalDependency):
-                for source in unholder(dep.sources):
+                for source in dep.sources:
                     if isinstance(source, GirTarget) and source not in depends:
                         depends.append(source)
                         subdir = os.path.join(state.environment.get_build_dir(),
@@ -846,7 +841,7 @@ class GnomeModule(ExtensionModule):
         langs_compilers = self._get_girtargets_langs_compilers(girtargets)
         cflags, internal_ldflags, external_ldflags = self._get_langs_compilers_flags(state, langs_compilers)
         deps = self._get_gir_targets_deps(girtargets)
-        deps += mesonlib.unholder(extract_as_list(kwargs, 'dependencies', pop=True))
+        deps += extract_as_list(kwargs, 'dependencies', pop=True)
         deps += [gir_dep]
         typelib_includes = self._gather_typelib_includes_and_update_depends(state, deps, depends)
         # ldflags will be misinterpreted by gir scanner (showing
@@ -898,7 +893,7 @@ class GnomeModule(ExtensionModule):
         if fatal_warnings:
             scan_command.append('--warn-error')
 
-        generated_files = [unholder(f) for f in libsources if isinstance(unholder(f), (GeneratedList, CustomTarget, CustomTargetIndex))]
+        generated_files = [f for f in libsources if isinstance(f, (GeneratedList, CustomTarget, CustomTargetIndex))]
 
         scan_target = self._make_gir_target(state, girfile, scan_command, generated_files, depends, kwargs)
 
@@ -1044,8 +1039,7 @@ class GnomeModule(ExtensionModule):
         src_dirs = mesonlib.extract_as_list(kwargs, 'src_dir')
         header_dirs = []
         for src_dir in src_dirs:
-            if hasattr(src_dir, 'held_object'):
-                src_dir = src_dir.held_object
+            if isinstance(src_dir, HoldableObject):
                 if not isinstance(src_dir, build.IncludeDirs):
                     raise MesonException('Invalid keyword argument for src_dir.')
                 for inc_dir in src_dir.get_incdirs():
@@ -1068,7 +1062,7 @@ class GnomeModule(ExtensionModule):
         for tool in ['scan', 'scangobj', 'mkdb', 'mkhtml', 'fixxref']:
             program_name = 'gtkdoc-' + tool
             program = state.find_program(program_name)
-            path = program.held_object.get_path()
+            path = program.get_path()
             args.append(f'--{program_name}={path}')
         if namespace:
             args.append('--namespace=' + namespace)
@@ -1082,7 +1076,7 @@ class GnomeModule(ExtensionModule):
 
         depends = []
         content_files = []
-        for s in unholder(mesonlib.extract_as_list(kwargs, 'content_files')):
+        for s in mesonlib.extract_as_list(kwargs, 'content_files'):
             if isinstance(s, (build.CustomTarget, build.CustomTargetIndex)):
                 depends.append(s)
                 for o in s.get_outputs():
@@ -1134,14 +1128,14 @@ class GnomeModule(ExtensionModule):
 
     def _get_build_args(self, kwargs, state, depends):
         args = []
-        deps = mesonlib.unholder(extract_as_list(kwargs, 'dependencies'))
+        deps = extract_as_list(kwargs, 'dependencies')
         cflags = []
         cflags.extend(mesonlib.stringlistify(kwargs.pop('c_args', [])))
         deps_cflags, internal_ldflags, external_ldflags, gi_includes = \
             self._get_dependencies_flags(deps, state, depends, include_rpath=True)
         inc_dirs = mesonlib.extract_as_list(kwargs, 'include_directories')
         for incd in inc_dirs:
-            if not isinstance(incd.held_object, (str, build.IncludeDirs)):
+            if not isinstance(incd, (str, build.IncludeDirs)):
                 raise MesonException(
                     'Gir include dirs should be include_directories().')
 
@@ -1678,7 +1672,7 @@ G_END_DECLS'''
         vapi_includes = []
         ret = []
         remaining_args = []
-        for arg in unholder(arg_list):
+        for arg in arg_list:
             if isinstance(arg, InternalDependency):
                 targets = [t for t in arg.sources if isinstance(t, VapiTarget)]
                 for target in targets:
@@ -1752,11 +1746,11 @@ G_END_DECLS'''
         for i in inputs:
             if isinstance(i, str):
                 cmd.append(os.path.join(source_dir, i))
-            elif hasattr(i, 'held_object') and isinstance(i.held_object, GirTarget):
-                link_with += self._get_vapi_link_with(i.held_object)
+            elif isinstance(i, GirTarget):
+                link_with += self._get_vapi_link_with(i)
                 subdir = os.path.join(state.environment.get_build_dir(),
-                                      i.held_object.get_subdir())
-                gir_file = os.path.join(subdir, i.held_object.get_outputs()[0])
+                                      i.get_subdir())
+                gir_file = os.path.join(subdir, i.get_outputs()[0])
                 cmd.append(gir_file)
             else:
                 raise MesonException('Input must be a str or GirTarget')
@@ -1791,4 +1785,10 @@ G_END_DECLS'''
         return ModuleReturnValue(rv, created_values)
 
 def initialize(*args, **kwargs):
-    return GnomeModule(*args, **kwargs)
+    mod = GnomeModule(*args, **kwargs)
+    mod.interpreter.append_holder_map(GResourceTarget, interpreter.CustomTargetHolder)
+    mod.interpreter.append_holder_map(GResourceHeaderTarget, interpreter.CustomTargetHolder)
+    mod.interpreter.append_holder_map(GirTarget, interpreter.CustomTargetHolder)
+    mod.interpreter.append_holder_map(TypelibTarget, interpreter.CustomTargetHolder)
+    mod.interpreter.append_holder_map(VapiTarget, interpreter.CustomTargetHolder)
+    return mod
diff --git a/mesonbuild/modules/hotdoc.py b/mesonbuild/modules/hotdoc.py
index 90635e6..26026fb 100644
--- a/mesonbuild/modules/hotdoc.py
+++ b/mesonbuild/modules/hotdoc.py
@@ -105,7 +105,6 @@ class HotdocTargetBuilder:
                 self.cmd.extend([option, value])
 
     def check_extra_arg_type(self, arg, value):
-        value = getattr(value, 'held_object', value)
         if isinstance(value, list):
             for v in value:
                 self.check_extra_arg_type(arg, v)
@@ -188,7 +187,6 @@ class HotdocTargetBuilder:
     def process_dependencies(self, deps):
         cflags = set()
         for dep in mesonlib.listify(ensure_list(deps)):
-            dep = getattr(dep, "held_object", dep)
             if isinstance(dep, InternalDependency):
                 inc_args = self.state.get_include_args(dep.include_directories)
                 cflags.update([self.replace_dirs_in_string(x)
@@ -232,7 +230,6 @@ class HotdocTargetBuilder:
     def flatten_config_command(self):
         cmd = []
         for arg in mesonlib.listify(self.cmd, flatten=True):
-            arg = getattr(arg, 'held_object', arg)
             if isinstance(arg, mesonlib.File):
                 arg = arg.absolute_path(self.state.environment.get_source_dir(),
                                         self.state.environment.get_build_dir())
@@ -371,7 +368,7 @@ class HotdocTargetHolder(CustomTargetHolder):
     def config_path_method(self, *args, **kwargs):
         conf = self.held_object.hotdoc_conf.absolute_path(self.interpreter.environment.source_dir,
                                                           self.interpreter.environment.build_dir)
-        return self.interpreter.holderify(conf)
+        return conf
 
 
 class HotdocTarget(build.CustomTarget):
@@ -422,7 +419,7 @@ class HotDocModule(ExtensionModule):
         project_name = args[0]
         builder = HotdocTargetBuilder(project_name, state, self.hotdoc, self.interpreter, kwargs)
         target, install_script = builder.make_targets()
-        targets = [HotdocTargetHolder(target, self.interpreter)]
+        targets = [target]
         if install_script:
             targets.append(install_script)
 
@@ -430,4 +427,6 @@ class HotDocModule(ExtensionModule):
 
 
 def initialize(interpreter):
-    return HotDocModule(interpreter)
+    mod = HotDocModule(interpreter)
+    mod.interpreter.append_holder_map(HotdocTarget, HotdocTargetHolder)
+    return mod
diff --git a/mesonbuild/modules/i18n.py b/mesonbuild/modules/i18n.py
index 98a8b0d..f10fdbe 100644
--- a/mesonbuild/modules/i18n.py
+++ b/mesonbuild/modules/i18n.py
@@ -108,7 +108,8 @@ class I18nModule(ExtensionModule):
         kwargs['command'] = command
 
         inputfile = kwargs['input']
-        if hasattr(inputfile, 'held_object'):
+        # I have no idea why/how this if isinstance(inputfile, mesonlib.HoldableObject) works / used to work...
+        if isinstance(inputfile, mesonlib.HoldableObject):
             ct = build.CustomTarget(kwargs['output'] + '_merge', state.subdir, state.subproject, kwargs)
         else:
             if isinstance(inputfile, list):
diff --git a/mesonbuild/modules/pkgconfig.py b/mesonbuild/modules/pkgconfig.py
index 13af3a6..f42c1e6 100644
--- a/mesonbuild/modules/pkgconfig.py
+++ b/mesonbuild/modules/pkgconfig.py
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import os, types
+import os
 from pathlib import PurePath
 
 from .. import build
@@ -22,7 +22,9 @@ from .. import mesonlib
 from .. import mlog
 from . import ModuleReturnValue
 from . import ExtensionModule
-from ..interpreterbase import permittedKwargs, FeatureNew, FeatureNewKwargs
+from ..interpreterbase import permittedKwargs, FeatureNew, FeatureNewKwargs, TYPE_var, TYPE_kwargs
+
+import typing as T
 
 already_warned_objs = set()
 
@@ -75,7 +77,7 @@ class DependenciesHelper:
     def _process_reqs(self, reqs):
         '''Returns string names of requirements'''
         processed_reqs = []
-        for obj in mesonlib.unholder(mesonlib.listify(reqs)):
+        for obj in mesonlib.listify(reqs):
             if not isinstance(obj, str):
                 FeatureNew.single_use('pkgconfig.generate requirement from non-string object', '0.46.0', self.state.subproject)
             if hasattr(obj, 'generated_pc'):
@@ -108,14 +110,13 @@ class DependenciesHelper:
     def add_cflags(self, cflags):
         self.cflags += mesonlib.stringlistify(cflags)
 
-    def _process_libs(self, libs, public):
-        libs = mesonlib.unholder(mesonlib.listify(libs))
+    def _process_libs(self, libs, public: bool):
+        libs = mesonlib.listify(libs)
         libs = [x.get_preferred_library() if isinstance(x, build.BothLibraries) else x for x in libs]
         processed_libs = []
         processed_reqs = []
         processed_cflags = []
         for obj in libs:
-            shared_library_only = getattr(obj, 'shared_library_only', False)
             if hasattr(obj, 'pcdep'):
                 pcdeps = mesonlib.listify(obj.pcdep)
                 for d in pcdeps:
@@ -488,7 +489,7 @@ class PkgConfigModule(ExtensionModule):
             FeatureNew.single_use('pkgconfig.generate implicit version keyword', '0.46.0', state.subproject)
         elif len(args) == 1:
             FeatureNew.single_use('pkgconfig.generate optional positional argument', '0.46.0', state.subproject)
-            mainlib = getattr(args[0], 'held_object', args[0])
+            mainlib = args[0]
             if not isinstance(mainlib, (build.StaticLibrary, build.SharedLibrary)):
                 raise mesonlib.MesonException('Pkgconfig_gen first positional argument must be a library object')
             default_name = mainlib.name
diff --git a/mesonbuild/modules/sourceset.py b/mesonbuild/modules/sourceset.py
index e413e32..eea3dbd 100644
--- a/mesonbuild/modules/sourceset.py
+++ b/mesonbuild/modules/sourceset.py
@@ -101,7 +101,6 @@ class SourceSet(MutableModuleObject):
             if_true = args
         elif args:
             raise InterpreterException('add_all called with both positional and keyword arguments')
-        if_true = mesonlib.unholder(if_true)
         keys, dependencies = self.check_conditions(when)
         for s in if_true:
             if not isinstance(s, SourceSet):
diff --git a/mesonbuild/modules/unstable_cuda.py b/mesonbuild/modules/unstable_cuda.py
index af65af3..a80f9ca 100644
--- a/mesonbuild/modules/unstable_cuda.py
+++ b/mesonbuild/modules/unstable_cuda.py
@@ -16,8 +16,7 @@ import typing as T
 import re
 
 from ..mesonlib import version_compare
-from ..interpreter import CompilerHolder
-from ..compilers import CudaCompiler
+from ..compilers import CudaCompiler, Compiler
 
 from . import ModuleObject
 
@@ -83,7 +82,7 @@ class CudaModule(ModuleObject):
 
     @permittedKwargs(['detected'])
     def nvcc_arch_flags(self, state: 'ModuleState',
-                              args: T.Tuple[T.Union[CompilerHolder, CudaCompiler, str]],
+                              args: T.Tuple[T.Union[Compiler, CudaCompiler, str]],
                               kwargs: T.Dict[str, T.Any]) -> T.List[str]:
         nvcc_arch_args = self._validate_nvcc_arch_args(args, kwargs)
         ret = self._nvcc_arch_flags(*nvcc_arch_args)[0]
@@ -91,7 +90,7 @@ class CudaModule(ModuleObject):
 
     @permittedKwargs(['detected'])
     def nvcc_arch_readable(self, state: 'ModuleState',
-                                 args: T.Tuple[T.Union[CompilerHolder, CudaCompiler, str]],
+                                 args: T.Tuple[T.Union[Compiler, CudaCompiler, str]],
                                  kwargs: T.Dict[str, T.Any]) -> T.List[str]:
         nvcc_arch_args = self._validate_nvcc_arch_args(args, kwargs)
         ret = self._nvcc_arch_flags(*nvcc_arch_args)[1]
@@ -105,16 +104,12 @@ class CudaModule(ModuleObject):
 
     @staticmethod
     def _detected_cc_from_compiler(c):
-        if isinstance(c, CompilerHolder):
-            c = c.compiler
         if isinstance(c, CudaCompiler):
             return c.detected_cc
         return ''
 
     @staticmethod
     def _version_from_compiler(c):
-        if isinstance(c, CompilerHolder):
-            c = c.compiler
         if isinstance(c, CudaCompiler):
             return c.version
         if isinstance(c, str):
diff --git a/mesonbuild/modules/unstable_rust.py b/mesonbuild/modules/unstable_rust.py
index f602e09..e5af2d7 100644
--- a/mesonbuild/modules/unstable_rust.py
+++ b/mesonbuild/modules/unstable_rust.py
@@ -109,7 +109,7 @@ class RustModule(ExtensionModule):
         ```
         """
         name = args[0]
-        base_target: BuildTarget = unholder(args[1])
+        base_target: BuildTarget = args[1]
         if not base_target.uses_rust():
             raise InterpreterException('Second positional argument to rustmod.test() must be a rust based target')
         extra_args = kwargs['args']
@@ -129,7 +129,7 @@ class RustModule(ExtensionModule):
                 del extra_args[i]
                 break
 
-        dependencies = [d.held_object for d in kwargs['dependencies']]
+        dependencies = [d for d in kwargs['dependencies']]
 
         # We need to cast here, as currently these don't have protocol in them, but test itself does.
         tkwargs = T.cast('_kwargs.FuncTest', kwargs.copy())
@@ -168,7 +168,7 @@ class RustModule(ExtensionModule):
         header: 'SourceOutputs'
         _deps: T.Sequence['SourceOutputs']
         try:
-            header, *_deps = unholder(self.interpreter.source_strings_to_files(listify(kwargs['input'])))
+            header, *_deps = self.interpreter.source_strings_to_files(listify(kwargs['input']))
         except KeyError:
             raise InvalidArguments('rustmod.bindgen() `input` argument must have at least one element.')
 
@@ -179,7 +179,7 @@ class RustModule(ExtensionModule):
         if not isinstance(output, str):
             raise InvalidArguments('rustmod.bindgen() `output` argument must be a string.')
 
-        include_dirs: T.List[IncludeDirs] = typeslistify(unholder(listify(kwargs.get('include_directories', []))), IncludeDirs)
+        include_dirs: T.List[IncludeDirs] = typeslistify(listify(kwargs.get('include_directories', [])), IncludeDirs)
         c_args: T.List[str] = stringlistify(listify(kwargs.get('c_args', [])))
         bind_args: T.List[str] = stringlistify(listify(kwargs.get('args', [])))
 
@@ -198,8 +198,7 @@ class RustModule(ExtensionModule):
             inc_strs.extend([f'-I{x}' for x in i.to_string_list(state.environment.get_source_dir())])
 
         if self._bindgen_bin is None:
-            # there's some bugs in the interpreter typeing.
-            self._bindgen_bin = state.find_program('bindgen').held_object
+            self._bindgen_bin = state.find_program('bindgen')
 
         name: str
         if isinstance(header, File):
diff --git a/mesonbuild/modules/unstable_simd.py b/mesonbuild/modules/unstable_simd.py
index df5faa1..3339cea 100644
--- a/mesonbuild/modules/unstable_simd.py
+++ b/mesonbuild/modules/unstable_simd.py
@@ -54,11 +54,11 @@ class SimdModule(ExtensionModule):
         for key, value in kwargs.items():
             if key not in self.isets and key != 'compiler':
                 basic_kwargs[key] = value
-        compiler = kwargs['compiler'].compiler
+        compiler = kwargs['compiler']
         if not isinstance(compiler, compilers.compilers.Compiler):
             raise mesonlib.MesonException('Compiler argument must be a compiler object.')
         cdata = self.interpreter.func_configuration_data(None, [], {})
-        conf = cdata.held_object
+        conf = cdata.conf_data
         for iset in self.isets:
             if iset not in kwargs:
                 continue
diff --git a/mesonbuild/modules/windows.py b/mesonbuild/modules/windows.py
index 441fb9f..d322833 100644
--- a/mesonbuild/modules/windows.py
+++ b/mesonbuild/modules/windows.py
@@ -18,10 +18,9 @@ import re
 
 from .. import mlog
 from .. import mesonlib, build
-from ..mesonlib import MachineChoice, MesonException, extract_as_list, unholder
+from ..mesonlib import MachineChoice, MesonException, extract_as_list
 from . import ModuleReturnValue
 from . import ExtensionModule
-from ..interpreter import CustomTargetHolder
 from ..interpreterbase import permittedKwargs, FeatureNewKwargs, flatten
 from ..programs import ExternalProgram
 
@@ -86,11 +85,13 @@ class WindowsModule(ExtensionModule):
         wrc_depend_files = extract_as_list(kwargs, 'depend_files', pop = True)
         wrc_depends = extract_as_list(kwargs, 'depends', pop = True)
         for d in wrc_depends:
-            if isinstance(d, CustomTargetHolder):
-                extra_args += state.get_include_args([d.outdir_include()])
+            if isinstance(d, build.CustomTarget):
+                extra_args += state.get_include_args([
+                    build.IncludeDirs('', [], False, [os.path.join('@BUILD_ROOT@', self.interpreter.backend.get_target_dir(d))])
+                ])
         inc_dirs = extract_as_list(kwargs, 'include_directories', pop = True)
         for incd in inc_dirs:
-            if not isinstance(incd.held_object, (str, build.IncludeDirs)):
+            if not isinstance(incd, (str, build.IncludeDirs)):
                 raise MesonException('Resource include dirs should be include_directories().')
         extra_args += state.get_include_args(inc_dirs)
 
@@ -120,7 +121,6 @@ class WindowsModule(ExtensionModule):
                 for subsrc in src:
                     add_target(subsrc)
                 return
-            src = unholder(src)
 
             if isinstance(src, str):
                 name_formatted = src