[clang-tidy] Don't ignore default set of checks when a config file is found.

Summary:
This makes clang-tidy merge the default set of checks with the one
provided in the configuration file instead of just using the checks from the
config file. This adds a way to modify the default set of checks while the
previous behavior required to always define the set of checks completely.

Reviewers: djasper

Reviewed By: djasper

Subscribers: curdeius, cfe-commits

Differential Revision: http://reviews.llvm.org/D7434

llvm-svn: 228298

1 files changed, 3 insertions, 4 deletions

diff --git a/clang-tools-extra/clang-tidy/ClangTidyOptions.cpp b/clang-tools-extra/clang-tidy/ClangTidyOptions.cpp
index 997529392ff..15ca2155399 100644
--- a/clang-tools-extra/clang-tidy/ClangTidyOptions.cpp
+++ b/clang-tools-extra/clang-tidy/ClangTidyOptions.cpp
@@ -241,10 +241,9 @@ FileOptionsProvider::TryReadConfigFile(StringRef Directory) {
       continue;
     }
 
-    ClangTidyOptions Defaults = DefaultOptionsProvider::getOptions(Directory);
-    // Only use checks from the config file.
-    Defaults.Checks = None;
-    return Defaults.mergeWith(*ParsedOptions).mergeWith(OverrideOptions);
+    return DefaultOptionsProvider::getOptions(Directory)
+        .mergeWith(*ParsedOptions)
+        .mergeWith(OverrideOptions);
   }
   return llvm::None;
 }