[ci] add all projects as dependencies of ci (#136153)

Add all projects as dependencies of .ci, to make sure everything is
tested when it changes.

Originally split-off from #135499

Author: mizvekov

.ci/compute_projects.py

@@ -52,6 +52,9 @@
     "clang": {"clang-tools-extra", "compiler-rt", "cross-project-tests"},
     "clang-tools-extra": {"libc"},
     "mlir": {"flang"},
+    # Test everything if ci scripts are changed.
+    # FIXME: Figure out what is missing and add here.
+    ".ci": {"llvm", "clang", "lld", "lldb"},
 }
 
 DEPENDENT_RUNTIMES_TO_TEST = {"clang": {"libcxx", "libcxxabi", "libunwind"}}
@@ -130,12 +133,11 @@ def _add_dependencies(projects: Set[str]) -> Set[str]:
 def _compute_projects_to_test(modified_projects: Set[str], platform: str) -> Set[str]:
     projects_to_test = set()
     for modified_project in modified_projects:
-        # Skip all projects where we cannot run tests.
-        if modified_project not in PROJECT_CHECK_TARGETS:
-            continue
         if modified_project in RUNTIMES:
             continue
-        projects_to_test.add(modified_project)
+        # Skip all projects where we cannot run tests.
+        if modified_project in PROJECT_CHECK_TARGETS:
+            projects_to_test.add(modified_project)
         if modified_project not in DEPENDENTS_TO_TEST:
             continue
         for dependent_project in DEPENDENTS_TO_TEST[modified_project]:

.ci/compute_projects_test.py

@@ -188,6 +188,23 @@ def test_exclude_gn(self):
         self.assertEqual(env_variables["runtimes_to_build"], "")
         self.assertEqual(env_variables["runtimes_check_targets"], "")
 
+    def test_ci(self):
+        env_variables = compute_projects.get_env_variables(
+            [".ci/compute_projects.py"], "Linux"
+        )
+        self.assertEqual(env_variables["projects_to_build"], "clang;lld;llvm;lldb")
+        self.assertEqual(
+            env_variables["project_check_targets"],
+            "check-clang check-lld check-llvm check-lldb",
+        )
+        self.assertEqual(
+            env_variables["runtimes_to_build"], "libcxx;libcxxabi;libunwind"
+        )
+        self.assertEqual(
+            env_variables["runtimes_check_targets"],
+            "check-cxx check-cxxabi check-unwind",
+        )
+
 
 if __name__ == "__main__":
     unittest.main()