scripts: Add tartan-json, a script for processing compile_commands.json

This script runs all the compilations listed in a compile_commands.json
file (generated by Meson and CMake) under the Tartan analyzer.

Use this script to analyze a whole project by passing it the compilation
database file generated by Meson or CMake. An example with Meson would
be:

    $ meson _build
    $ tartan-json _build/compile_commands.json

See: #39

2 files changed, 68 insertions, 0 deletions

diff --git a/Makefile.am b/Makefile.am
index 764ca8c..319e3d7 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -74,6 +74,7 @@ clang_plugin_libtartan_la_LDFLAGS = \
 dist_bin_SCRIPTS = \
 	scripts/tartan \
 	scripts/tartan-build \
+	scripts/tartan-json \
 	$(NULL)
 
 # Code coverage
diff --git a/scripts/tartan-json b/scripts/tartan-json
new file mode 100755
index 0000000..560413a
--- /dev/null
+++ b/scripts/tartan-json
@@ -0,0 +1,67 @@
+#!/usr/bin/env python3
+# coding: utf8
+#
+# This file is part of Tartan.
+# Copyright © 2019 Philip Chimento
+#
+# Tartan is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Tartan is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Tartan.  If not, see <http://www.gnu.org/licenses/>.
+
+# Use this script to analyze a whole project by passing it the compilation
+# database file generated by Meson or CMake. An example with Meson would be:
+#
+#  $ meson _build
+#  $ tartan-json _build/compile_commands.json
+
+import argparse
+import json
+import os
+import shlex
+import subprocess
+import sys
+
+parser = argparse.ArgumentParser(
+    description='''Run the Tartan analyzer on a whole compilation database, in
+the compile_commands.json format such as generated by Meson or CMake.''')
+parser.add_argument('json', type=argparse.FileType('r'), metavar='FILE',
+                    help='path to compile_commands.json')
+parser.add_argument('-q', '--quiet', action='store_true',
+                    help="don't print progress messages")
+parser.add_argument('tartan_options', nargs=argparse.REMAINDER, metavar='...',
+                    help='extra options to pass on to Tartan')
+
+args = parser.parse_args()
+
+compile_db = json.load(args.json)
+had_error = False
+
+for index, entry in enumerate(compile_db):
+    if not args.quiet:
+        full_path = os.path.normpath(os.path.join(entry['directory'],
+                                                  entry['file']))
+        print('[{}/{}] Processing {}'.format(index + 1, len(compile_db),
+                                             full_path))
+
+    new_env = dict(os.environ)
+    existing_tartan_options = new_env.get('TARTAN_OPTIONS', '')
+    new_env['TARTAN_OPTIONS'] = (existing_tartan_options + ' ' +
+                                 ' '.join(args.tartan_options))
+    # -Wno-unused-command-line-argument is because linker arguments will be
+    # ignored and produce a warning with --analyze.
+    invocation = (['tartan', '--analyze', '-Wno-unused-command-line-argument']
+                  + shlex.split(entry['command']))
+    result = subprocess.run(invocation, cwd=entry['directory'], env=new_env)
+    if result.returncode != 0:
+        had_error = True
+
+sys.exit(1 if had_error else 0)