Add a clang-format target.

8 files changed, 143 insertions, 2 deletions

diff --git a/docs/markdown/snippets/clangformat.md b/docs/markdown/snippets/clangformat.md
new file mode 100644
index 000000000..89832432d
--- /dev/null
+++ b/docs/markdown/snippets/clangformat.md
@@ -0,0 +1,11 @@
+## A builtin target to run clang-format
+
+If you have `clang-format` installed and there is a `.clang-format`
+file in the root of your master project, Meson will generate a run
+target called `clang-format` so you can reformat all files with one
+command:
+
+```meson
+ninja clang-format
+```
+
diff --git a/mesonbuild/backend/ninjabackend.py b/mesonbuild/backend/ninjabackend.py
index f49649be4..5d59fa975 100644
--- a/mesonbuild/backend/ninjabackend.py
+++ b/mesonbuild/backend/ninjabackend.py
@@ -2579,8 +2579,7 @@ rule FORTRAN_DEP_HACK%s
         # Alias that runs the target defined above
         self.create_target_alias('meson-dist', outfile)
 
-    # For things like scan-build and other helper tools we might have.
-    def generate_utils(self, outfile):
+    def generate_scanbuild(self, outfile):
         cmd = self.environment.get_build_command() + \
             ['--internal', 'scanbuild', self.environment.source_dir, self.environment.build_dir] + \
             self.environment.get_build_command() + self.get_user_option_args()
@@ -2590,6 +2589,29 @@ rule FORTRAN_DEP_HACK%s
         elem.write(outfile)
         # Alias that runs the target defined above
         self.create_target_alias('meson-scan-build', outfile)
+
+    def generate_clangformat(self, outfile):
+        import shutil
+        target_name = 'clang-format'
+        if shutil.which('clang-format') is None:
+            return
+        if not os.path.exists(os.path.join(self.environment.source_dir, '.clang-format')) and \
+                not os.path.exists(os.path.join(self.environment.source_dir, '_clang-format')):
+            return
+        if 'target_name' in self.all_outputs:
+            return
+        cmd = self.environment.get_build_command() + \
+            ['--internal', 'clangformat', self.environment.source_dir, self.environment.build_dir]
+        elem = NinjaBuildElement(self.all_outputs, 'meson-' + target_name, 'CUSTOM_COMMAND', 'PHONY')
+        elem.add_item('COMMAND', cmd)
+        elem.add_item('pool', 'console')
+        elem.write(outfile)
+        self.create_target_alias('meson-' + target_name, outfile)
+
+    # For things like scan-build and other helper tools we might have.
+    def generate_utils(self, outfile):
+        self.generate_scanbuild(outfile)
+        self.generate_clangformat(outfile)
         cmd = self.environment.get_build_command() + ['--internal', 'uninstall']
         elem = NinjaBuildElement(self.all_outputs, 'meson-uninstall', 'CUSTOM_COMMAND', 'PHONY')
         elem.add_item('COMMAND', cmd)
diff --git a/mesonbuild/scripts/clangformat.py b/mesonbuild/scripts/clangformat.py
new file mode 100644
index 000000000..fcdf5af74
--- /dev/null
+++ b/mesonbuild/scripts/clangformat.py
@@ -0,0 +1,37 @@
+# Copyright 2018 The Meson development team
+
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+
+#     http://www.apache.org/licenses/LICENSE-2.0
+
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import pathlib
+import subprocess
+from concurrent.futures import ThreadPoolExecutor
+
+from ..compilers import lang_suffixes
+
+def clangformat(srcdir_name, builddir_name):
+    srcdir = pathlib.Path(srcdir_name)
+    suffixes = set(lang_suffixes['c']).union(set(lang_suffixes['cpp']))
+    futures = []
+    with ThreadPoolExecutor() as e:
+        for f in (x for suff in suffixes for x in srcdir.glob('**/*.' + suff)):
+            strf = str(f)
+            if strf.startswith(builddir_name):
+                continue
+            futures.append(e.submit(subprocess.check_call, ['clang-format', '-style=file', '-i', strf]))
+        [x.result() for x in futures]
+    return 0
+
+def run(args):
+    srcdir_name = args[0]
+    builddir_name = args[1]
+    return clangformat(srcdir_name, builddir_name)
diff --git a/run_unittests.py b/run_unittests.py
index 91daa1b2f..f8ede9b89 100755
--- a/run_unittests.py
+++ b/run_unittests.py
@@ -102,6 +102,19 @@ def _git_init(project_dir):
     subprocess.check_call(['git', 'commit', '-a', '-m', 'I am a project'], cwd=project_dir,
                           stdout=subprocess.DEVNULL)
 
+def skipIfNoExecutable(exename):
+    '''
+    Skip this test if the given executable is not found.
+    '''
+    def wrapper(func):
+        @functools.wraps(func)
+        def wrapped(*args, **kwargs):
+            if shutil.which(exename) is None:
+                raise unittest.SkipTest(exename + ' not found')
+            return func(*args, **kwargs)
+        return wrapped
+    return wrapper
+
 def skipIfNoPkgconfig(f):
     '''
     Skip this test if no pkg-config is found, unless we're on CI.
@@ -3053,6 +3066,28 @@ recommended as it is not supported on some platforms''')
         }
         self.assertDictEqual(res, expected)
 
+    @skipIfNoExecutable('clang-format')
+    def test_clang_format(self):
+        if self.backend is not Backend.ninja:
+            raise unittest.SkipTest('Clang-format is for now only supported on Ninja, not {}'.format(self.backend.name))
+        testdir = os.path.join(self.unit_test_dir, '51 clang-format')
+        testfile = os.path.join(testdir, 'prog.c')
+        badfile = os.path.join(testdir, 'prog_orig_c')
+        goodfile = os.path.join(testdir, 'prog_expected_c')
+        try:
+            self.run_clangformat(testdir, testfile, badfile, goodfile)
+        finally:
+            if os.path.exists(testfile):
+                os.unlink(testfile)
+
+    def run_clangformat(self, testdir, testfile, badfile, goodfile):
+        shutil.copyfile(badfile, testfile)
+        self.init(testdir)
+        self.assertNotEqual(Path(testfile).read_text(),
+                            Path(goodfile).read_text())
+        self.run_target('clang-format')
+        self.assertEqual(Path(testfile).read_text(),
+                         Path(goodfile).read_text())
 
 class FailureTests(BasePlatformTests):
     '''
diff --git a/test cases/unit/51 clang-format/.clang-format b/test cases/unit/51 clang-format/.clang-format
new file mode 100644
index 000000000..5c60ac9f3
--- /dev/null
+++ b/test cases/unit/51 clang-format/.clang-format
@@ -0,0 +1,5 @@
+---
+BasedOnStyle: LLVM
+IndentWidth: 4
+UseTab: Never
+---
diff --git a/test cases/unit/51 clang-format/meson.build b/test cases/unit/51 clang-format/meson.build
new file mode 100644
index 000000000..1b93cd54d
--- /dev/null
+++ b/test cases/unit/51 clang-format/meson.build
@@ -0,0 +1,4 @@
+project('clangformat', 'c')
+
+executable('prog', 'prog.c')
+
diff --git a/test cases/unit/51 clang-format/prog_expected_c b/test cases/unit/51 clang-format/prog_expected_c
new file mode 100644
index 000000000..a045966a7
--- /dev/null
+++ b/test cases/unit/51 clang-format/prog_expected_c
@@ -0,0 +1,6 @@
+#include <stdio.h>
+
+int main(int argc, char **argv) {
+    printf("Awful.\n");
+    return 0;
+}
diff --git a/test cases/unit/51 clang-format/prog_orig_c b/test cases/unit/51 clang-format/prog_orig_c
new file mode 100644
index 000000000..f098bbcce
--- /dev/null
+++ b/test cases/unit/51 clang-format/prog_orig_c
@@ -0,0 +1,21 @@
+#include    <stdio.h>
+
+
+
+
+int
+main(
+int
+argc,
+char**
+argv)
+{
+printf(
+"Awful.\n"
+)
+;
+return
+0
+;
+}
+