[clang-tidy] add option to specify build path

Summary:
compile_commands.json is usually generated in the build directory.
Projects like LLVM/Clang enforce out-of-source builds.
This option allow allow such projects to work out of the box, without
moving the compilation database manually.

The naming of the option is similar to the one use by other tools:

    clang-{check,modernize,query,rename,tidy} -p=<build_path> <...>

Reviewers: alexfh

Differential Revision: http://reviews.llvm.org/D13199

llvm-svn: 248723

1 files changed, 11 insertions, 4 deletions

diff --git a/clang-tools-extra/clang-tidy/tool/run-clang-tidy.py b/clang-tools-extra/clang-tidy/tool/run-clang-tidy.py
index 73c5140a180..e4dd3da447e 100755
--- a/clang-tools-extra/clang-tidy/tool/run-clang-tidy.py
+++ b/clang-tools-extra/clang-tidy/tool/run-clang-tidy.py
@@ -128,10 +128,21 @@ def main():
   parser.add_argument('-fix', action='store_true', help='apply fix-its')
   parser.add_argument('-format', action='store_true', help='Reformat code '
                       'after applying fixes')
+  parser.add_argument('-p', dest='build_path',
+                      help='Path used to read a compile command database.')
   args = parser.parse_args()
 
+  db_path = 'compile_commands.json'
+
+  if args.build_path is not None:
+    build_path = args.build_path
+  else:
+    # Find our database
+    build_path = find_compilation_database(db_path)
+
   try:
     invocation = [args.clang_tidy_binary, '-list-checks']
+    invocation.append('-p=' + build_path)
     if args.checks:
       invocation.append('-checks=' + args.checks)
     invocation.append('-')
@@ -140,10 +151,6 @@ def main():
     print >>sys.stderr, "Unable to run clang-tidy."
     sys.exit(1)
 
-  # Find our database.
-  db_path = 'compile_commands.json'
-  build_path = find_compilation_database(db_path)
-
   # Load the database and extract all files.
   database = json.load(open(os.path.join(build_path, db_path)))
   files = [entry['file'] for entry in database]