qt: register existing .qrc to fix build dependencies

mesonbuild/build.py

@@ -2186,12 +2186,14 @@ class Generator(HoldableObject):
                  depfile: T.Optional[str] = None,
                  capture: bool = False,
                  depends: T.Optional[T.Sequence[TargetDepends]] = None,
+                 depend_files: T.Optional[T.Sequence[File]] = None,
                  name: str = 'Generator'):
         self.environment = env
         self.exe = exe
         self.depfile = depfile
         self.capture = capture
         self.depends: T.List[TargetDepends] = list(depends or [])
+        self.depend_files: T.List[File] = list(depend_files or [])
         self.arglist = arguments
         self.outputs = output
         self.name = name
@@ -2279,7 +2281,7 @@ class GeneratedList(HoldableObject):
         self.infilelist: T.List[FileMaybeInTargetPrivateDir] = []
         self.outfilelist: T.List[str] = []
         self.outmap: T.Dict[FileMaybeInTargetPrivateDir, T.List[str]] = {}
-        self.depend_files: T.List[File] = []
+        self.depend_files: T.List[File] = self.generator.depend_files.copy()
 
         if self.extra_args is None:
             self.extra_args: T.List[str] = []

mesonbuild/modules/_qt.py

@@ -914,6 +914,7 @@ class QtBaseModule(ExtensionModule):
             self.tools['qmlcachegen'],
             command_args,
             [f'{target_name}_@BASENAME@.cpp'],
+            depend_files=[kwargs['qml_qrc']],
             name=f'Qml cache generation for {target_name}')
 
         output: T.List[T.Union[build.CustomTarget, build.GeneratedList]] = []

test cases/unit/146 qml cache resource dependency/Main.qml

@@ -0,0 +1,5 @@
+import QtQml
+
+QtObject {
+    property int answer: 42
+}

test cases/unit/146 qml cache resource dependency/meson.build

@@ -0,0 +1,17 @@
+project('qml cache resource dependency', 'cpp', meson_version: '>= 1.7.0')
+
+qt = import('qt6')
+qtdep = dependency('qt6', modules: ['Core', 'Qml'], version: '>= 6.2', required: false)
+if not qtdep.found() or not qt.has_tools(tools: ['qmlcachegen', 'rcc'], required: false)
+  error('MESON_SKIP_TEST Qt6 QML tools not found')
+endif
+
+sources = qt.qml_module(
+  'MyModule',
+  qml_sources: files('Main.qml'),
+  generate_qmltype: false,
+  resources_prefix: get_option('resource_prefix'),
+)
+
+# Only build the generated sources: compiling them would require Qt's private headers.
+static_library('cache', sources, name_prefix: '', name_suffix: 'a', dependencies: qtdep)

test cases/unit/146 qml cache resource dependency/meson.options

@@ -0,0 +1 @@
+option('resource_prefix', type: 'string', value: '/old')

unittests/allplatformstests.py

@@ -1521,6 +1521,22 @@ class AllPlatformTests(BasePlatformTests):
         self.utime(os.path.join(testdir, 'srcgen.py'))
         self.assertRebuiltTarget('basic')
 
+    def test_qml_cache_resource_dependency(self):
+        if self.backend is not Backend.ninja:
+            raise SkipTest('This test requires the Ninja backend')
+        testdir = os.path.join(self.unit_test_dir, '146 qml cache resource dependency')
+        self.init(testdir)
+        cache_source = 'cache.a.p/MyModule_Main.cpp'
+        loader = 'MyModule_qmlcache_loader.cpp'
+        self.build(cache_source, extra_args=[loader])
+        for source in (cache_source, loader):
+            self.assertIn('_old_MyModule_Main_qml', Path(self.builddir, source).read_text(encoding='utf-8'))
+
+        self.setconf('-Dresource_prefix=/new', will_build=False)
+        self.build(cache_source, extra_args=[loader])
+        for source in (cache_source, loader):
+            self.assertIn('_new_MyModule_Main_qml', Path(self.builddir, source).read_text(encoding='utf-8'))
+
     def test_long_opt_vs_D(self):
         '''
         Test that conflicts between -D for builtin options and the corresponding