[clang-tidy] Store checks profiling info as JSON files

Summary:
Continuation of D46504.

Example output:
```
  $ clang-tidy -enable-check-profile -store-check-profile=. -checks=-*,readability-function-size source.cpp
  $ # Note that there won't be timings table printed to the console.
  $ cat *.json
  {
  "file": "/path/to/source.cpp",
  "timestamp": "2018-05-16 16:13:18.717446360",
  "profile": {
    "time.clang-tidy.readability-function-size.wall": 1.0421266555786133e+00,
    "time.clang-tidy.readability-function-size.user": 9.2088400000005421e-01,
    "time.clang-tidy.readability-function-size.sys": 1.2418899999999974e-01
  }
  }
```

There are two arguments that control profile storage:

* `-store-check-profile=<prefix>`

  By default reports are printed in tabulated format to stderr. When this option
  is passed, these per-TU profiles are instead stored as JSON.
  If the prefix is not an absolute path, it is considered to be relative to the
  directory from where you have run :program:`clang-tidy`. All `.` and `..`
  patterns in the path are collapsed, and symlinks are resolved.

  Example:
  Let's suppose you have a source file named `example.cpp`, located in
  `/source` directory.

  * If you specify `-store-check-profile=/tmp`, then the profile will be saved
    to `/tmp/<timestamp>-example.cpp.json`

  * If you run :program:`clang-tidy` from within `/foo` directory, and specify
    `-store-check-profile=.`, then the profile will still be saved to
    `/foo/<timestamp>-example.cpp.json`

Reviewers: alexfh, sbenza, george.karpenkov, NoQ, aaron.ballman

Reviewed By: alexfh, george.karpenkov, aaron.ballman

Subscribers: Quuxplusone, JonasToth, aaron.ballman, llvm-commits, rja, Eugene.Zelenko, xazax.hun, mgrang, cfe-commits

Tags: #clang-tools-extra

Differential Revision: https://reviews.llvm.org/D46602

git-svn-id: https://llvm.org/svn/llvm-project/clang-tools-extra/trunk@334101 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 5 insertions, 1 deletions

diff --git a/clang-tidy/ClangTidy.h b/clang-tidy/ClangTidy.h
index 4ee38a04..0ea9a701 100644
--- a/clang-tidy/ClangTidy.h
+++ b/clang-tidy/ClangTidy.h
@@ -227,11 +227,15 @@ getCheckOptions(const ClangTidyOptions &Options,
 ///
 /// \param EnableCheckProfile If provided, it enables check profile collection
 /// in MatchFinder, and will contain the result of the profile.
+/// \param StoreCheckProfile If provided, and EnableCheckProfile is true,
+/// the profile will not be output to stderr, but will instead be stored
+/// as a JSON file in the specified directory.
 void runClangTidy(clang::tidy::ClangTidyContext &Context,
                   const tooling::CompilationDatabase &Compilations,
                   ArrayRef<std::string> InputFiles,
                   llvm::IntrusiveRefCntPtr<vfs::FileSystem> BaseFS,
-                  bool EnableCheckProfile = false);
+                  bool EnableCheckProfile = false,
+                  llvm::StringRef StoreCheckProfile = StringRef());
 
 // FIXME: This interface will need to be significantly extended to be useful.
 // FIXME: Implement confidence levels for displaying/fixing errors.