xcode: Check custom target input for extracted objects

If there are any specified, the build target that generates them must
be added as a dependency.

mesonbuild/backend/xcodebackend.py

@@ -585,12 +585,15 @@ class XCodeBackend(backends.Backend):
                 elif isinstance(d, build.BuildTarget):
                     dependencies.append(self.pbx_dep_map[d.get_id()])
             for s in t.sources:
-                if not isinstance(s, build.GeneratedList):
-                    continue
-                build_phases.append(self.shell_targets[(tname, generator_id)])
-                for d in s.depends:
-                    dependencies.append(self.pbx_custom_dep_map[d.get_id()])
-                generator_id += 1
+                if isinstance(s, build.GeneratedList):
+                    build_phases.append(self.shell_targets[(tname, generator_id)])
+                    for d in s.depends:
+                        dependencies.append(self.pbx_custom_dep_map[d.get_id()])
+                    generator_id += 1
+                elif isinstance(s, build.ExtractedObjects):
+                    source_target_id = self.pbx_dep_map[s.target.get_id()]
+                    if source_target_id not in dependencies:
+                        dependencies.append(source_target_id)
             build_phases.append(self.shell_targets[tname])
             aggregated_targets.append((ct_id, tname, self.buildconflistmap[tname], build_phases, dependencies))