dependencies: Add ability to set arbitrary variables on

declare_dependencies

This allows dependencies declared in subprojects to set variables, and
for those variables to be accessed via the get_variable method, just
like those from pkg-config and cmake. This makes it easier to use
projects from subprojects in a polymorphic manner, lowering the
distinction between a subproject and an external dependency every
further.

mesonbuild/build.py

@@ -1053,7 +1053,7 @@ This will become a hard error in a future Meson release.''')
                                                               [],
                                                               dep.get_compile_args(),
                                                               dep.get_link_args(),
-                                                              [], [], [], [])
+                                                              [], [], [], [], {})
                     self.external_deps.append(extpart)
                 # Deps of deps.
                 self.add_deps(dep.ext_deps)

mesonbuild/dependencies/base.py

@@ -223,7 +223,8 @@ class Dependency:
         self.ext_deps.append(dep_type(env, kwargs))
 
     def get_variable(self, *, cmake: T.Optional[str] = None, pkgconfig: T.Optional[str] = None,
-                     configtool: T.Optional[str] = None, default_value: 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 default_value is not None:
             return default_value
@@ -235,7 +236,8 @@ class Dependency:
         return new_dep
 
 class InternalDependency(Dependency):
-    def __init__(self, version, incdirs, compile_args, link_args, libraries, whole_libraries, sources, ext_deps):
+    def __init__(self, version, incdirs, compile_args, link_args, libraries,
+                 whole_libraries, sources, ext_deps, variables: T.Dict[str, T.Any]):
         super().__init__('internal', {})
         self.version = version
         self.is_found = True
@@ -246,6 +248,7 @@ class InternalDependency(Dependency):
         self.whole_libraries = whole_libraries
         self.sources = sources
         self.ext_deps = ext_deps
+        self.variables = variables
 
     def get_pkgconfig_variable(self, variable_name, kwargs):
         raise DependencyException('Method "get_pkgconfig_variable()" is '
@@ -270,7 +273,17 @@ class InternalDependency(Dependency):
         return InternalDependency(
             self.version, final_includes, final_compile_args,
             final_link_args, final_libraries, final_whole_libraries,
-            final_sources, final_deps)
+            final_sources, final_deps, self.variables)
+
+    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]]:
+        val = self.variables.get(internal, default_value)
+        if val is not None:
+            return val
+        raise DependencyException('Could not get an internal variable and no default provided for {!r}'.format(self))
+
 
 class HasNativeKwarg:
     def __init__(self, kwargs):
@@ -554,7 +567,8 @@ class ConfigToolDependency(ExternalDependency):
         return self.type_name
 
     def get_variable(self, *, cmake: T.Optional[str] = None, pkgconfig: T.Optional[str] = None,
-                     configtool: T.Optional[str] = None, default_value: 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 configtool:
             # In the not required case '' (empty string) will be returned if the
@@ -1007,7 +1021,8 @@ class PkgConfigDependency(ExternalDependency):
         return self.type_name
 
     def get_variable(self, *, cmake: T.Optional[str] = None, pkgconfig: T.Optional[str] = None,
-                     configtool: T.Optional[str] = None, default_value: 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 = {}
@@ -1549,7 +1564,8 @@ project(MesonTemp LANGUAGES {})
         return ''
 
     def get_variable(self, *, cmake: T.Optional[str] = None, pkgconfig: T.Optional[str] = None,
-                     configtool: T.Optional[str] = None, default_value: 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 cmake:
             try:

mesonbuild/interpreter.py

@@ -483,7 +483,8 @@ class DependencyHolder(InterpreterObject, ObjectHolder):
 
     @FeatureNew('dep.get_variable', '0.51.0')
     @noPosargs
-    @permittedKwargs({'cmake', 'pkgconfig', 'configtool', 'default_value', 'pkgconfig_define'})
+    @permittedKwargs({'cmake', 'pkgconfig', 'configtool', 'internal', 'default_value', 'pkgconfig_define'})
+    @FeatureNewKwargs('dep.get_variable', '0.54.0', ['internal'])
     def variable_method(self, args, kwargs):
         return self.held_object.get_variable(**kwargs)
 
@@ -2087,6 +2088,7 @@ permitted_kwargs = {'add_global_arguments': {'language', 'native'},
                                            'link_args',
                                            'link_whole',
                                            'version',
+                                           'variables',
                                            },
                     'executable': build.known_exe_kwargs,
                     'find_program': {'required', 'native', 'version', 'dirs'},
@@ -2385,6 +2387,7 @@ class Interpreter(InterpreterBase):
         return [mesonlib.File.from_source_file(self.environment.source_dir, self.subdir, fname) for fname in args]
 
     @FeatureNewKwargs('declare_dependency', '0.46.0', ['link_whole'])
+    @FeatureNewKwargs('declare_dependency', '0.54.0', ['variables'])
     @permittedKwargs(permitted_kwargs['declare_dependency'])
     @noPosargs
     def func_declare_dependency(self, node, args, kwargs):
@@ -2399,6 +2402,12 @@ class Interpreter(InterpreterBase):
         deps = extract_as_list(kwargs, 'dependencies', unholder=True)
         compile_args = mesonlib.stringlistify(kwargs.get('compile_args', []))
         link_args = mesonlib.stringlistify(kwargs.get('link_args', []))
+        variables = kwargs.get('variables', {})
+        if not isinstance(variables, dict):
+            raise InterpreterException('variables must be a dict.')
+        if not all(isinstance(v, str) for v in variables.values()):
+            # Because that is how they will come from pkg-config and cmake
+            raise InterpreterException('variables values be strings.')
         final_deps = []
         for d in deps:
             try:
@@ -2413,7 +2422,8 @@ class Interpreter(InterpreterBase):
                 raise InterpreterException('''Entries in "link_with" may only be self-built targets,
 external dependencies (including libraries) must go to "dependencies".''')
         dep = dependencies.InternalDependency(version, incs, compile_args,
-                                              link_args, libs, libs_whole, sources, final_deps)
+                                              link_args, libs, libs_whole, sources, final_deps,
+                                              variables)
         return DependencyHolder(dep, self.subproject)
 
     @noKwargs

mesonbuild/modules/gnome.py

@@ -1692,7 +1692,7 @@ G_END_DECLS'''
         # - add relevant directories to include dirs
         incs = [build.IncludeDirs(state.subdir, ['.'] + vapi_includes, False)]
         sources = [vapi_target] + vapi_depends
-        rv = InternalDependency(None, incs, [], [], link_with, [], sources, [])
+        rv = InternalDependency(None, incs, [], [], link_with, [], sources, [], {})
         created_values.append(rv)
         return ModuleReturnValue(rv, created_values)
 

test cases/common/218 dependency get_variable method/meson.build

@@ -47,6 +47,15 @@ else
         'cmake config-tool got default when we shouldn\'t have.')
 endif
 
+idep = declare_dependency(variables : {'foo' : 'value'})
+assert(idep.get_variable(pkgconfig : 'foo', cmake : 'foo', configtool : 'foo',
+                         internal : 'foo', default_value : default) == 'value',
+       'internal got default when it shouldn\'t have.')
+assert(idep.get_variable(pkgconfig : 'foo', cmake : 'foo', configtool : 'foo',
+                         internal : 'bar', default_value : default) == default,
+       'internal didn\'t default when it should have.')
+
 idep = declare_dependency()
-assert(idep.get_variable(pkgconfig : 'foo', cmake : 'foo', configtool : 'foo', default_value : default) == default,
+assert(idep.get_variable(pkgconfig : 'foo', cmake : 'foo', configtool : 'foo',
-       'Got something other than default from an internal dependency')
+                         default_value : default) == default,
+       'something went wrong with an InternalDependency with no variables.')