Add clang-tidy-fix target

Add the `clang-tidy-fix` target to apply clang-tidy fixes to the source
code.
This is done by calling `run-clang-tidy` with `-fix` argument.

Add a test case to run `clang-tidy-fix` and verify the file is changed.

Signed-off-by: Lei YU <yulei.sh@bytedance.com>

2 files changed, 25 insertions, 2 deletions

diff --git a/unittests/allplatformstests.py b/unittests/allplatformstests.py
index acab026..f06279a 100644
--- a/unittests/allplatformstests.py
+++ b/unittests/allplatformstests.py
@@ -42,7 +42,7 @@ from mesonbuild.mesonlib import (
     is_sunos, windows_proof_rmtree, python_command, version_compare, split_args, quote_arg,
     relpath, is_linux, git, search_version, do_conf_file, do_conf_str, default_prefix,
     MesonException, EnvironmentException, OptionKey,
-    windows_proof_rm
+    windows_proof_rm, quiet_git
 )
 from mesonbuild.programs import ExternalProgram
 
@@ -3029,6 +3029,26 @@ class AllPlatformTests(BasePlatformTests):
         self.assertIn('cttest.cpp:4:20', out)
         self.assertNotIn(dummydir, out)
 
+    @skipIfNoExecutable('clang-tidy')
+    @unittest.skipIf(not is_git_repo(), 'Skipping because this is not in git repo')
+    def test_clang_tidy_fix(self):
+        if self.backend is not Backend.ninja:
+            raise SkipTest(f'Clang-tidy is for now only supported on Ninja, not {self.backend.name}')
+        if shutil.which('c++') is None:
+            raise SkipTest('Clang-tidy breaks when ccache is used and "c++" not in path.')
+        if is_osx():
+            raise SkipTest('Apple ships a broken clang-tidy that chokes on -pipe.')
+        testdir = os.path.join(self.unit_test_dir, '68 clang-tidy')
+        dummydir = os.path.join(testdir, 'dummydir.h')
+        self.init(testdir, override_envvars={'CXX': 'c++'})
+        out = self.run_target('clang-tidy-fix')
+        self.assertIn('cttest.cpp:4:20', out)
+        self.assertNotIn(dummydir, out)
+        ret = quiet_git(['diff', '--exit-code', 'test cases/unit/68 clang-tidy/cttest.cpp'], '.')
+        self.assertFalse(ret[0])
+        # Restore the file
+        quiet_git(['checkout', '--', 'test cases/unit/68 clang-tidy/cttest.cpp'], '.')
+
     def test_identity_cross(self):
         testdir = os.path.join(self.unit_test_dir, '69 cross')
         # Do a build to generate a cross file where the host is this target
diff --git a/unittests/helpers.py b/unittests/helpers.py
index 7483f51..83327cb 100644
--- a/unittests/helpers.py
+++ b/unittests/helpers.py
@@ -12,7 +12,7 @@ from contextlib import contextmanager
 from mesonbuild.compilers import detect_c_compiler, compiler_from_language
 from mesonbuild.mesonlib import (
     MachineChoice, is_osx, is_cygwin, EnvironmentException, OptionKey, MachineChoice,
-    OrderedSet
+    OrderedSet, quiet_git
 )
 from run_tests import get_fake_env
 
@@ -135,6 +135,9 @@ def is_tarball():
         return True
     return False
 
+def is_git_repo():
+    return quiet_git(['branch'], '.')[0]
+
 @contextmanager
 def chdir(path: str):
     curdir = os.getcwd()