clang-format: [JS] sort ES6 imports.

Summary:
This change automatically sorts ES6 imports and exports into four groups:
absolute imports, parent imports, relative imports, and then exports. Exports
are sorted in the same order, but not grouped further.

To keep JS import sorting out of Format.cpp, this required extracting the
TokenAnalyzer infrastructure to separate header and implementation files.

Reviewers: djasper

Subscribers: cfe-commits, klimek

Differential Revision: http://reviews.llvm.org/D20198

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@270203 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 36 insertions, 0 deletions

diff --git a/lib/Format/SortJavaScriptImports.h b/lib/Format/SortJavaScriptImports.h
new file mode 100644
index 0000000000..f22a051008
--- /dev/null
+++ b/lib/Format/SortJavaScriptImports.h
@@ -0,0 +1,36 @@
+//===--- SortJavaScriptImports.h - Sort ES6 Imports -------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// \brief This file implements a sorter for JavaScript ES6 imports.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_LIB_FORMAT_SORTJAVASCRIPTIMPORTS_H
+#define LLVM_CLANG_LIB_FORMAT_SORTJAVASCRIPTIMPORTS_H
+
+#include "clang/Basic/LLVM.h"
+#include "clang/Format/Format.h"
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/StringRef.h"
+
+namespace clang {
+namespace format {
+
+// Sort JavaScript ES6 imports/exports in ``Code``. The generated replacements
+// only monotonically increase the length of the given code.
+tooling::Replacements sortJavaScriptImports(const FormatStyle &Style,
+                                            StringRef Code,
+                                            ArrayRef<tooling::Range> Ranges,
+                                            StringRef FileName);
+
+} // end namespace format
+} // end namespace clang
+
+#endif