[refactor] initial support for refactoring action rules

This patch implements the initial support for refactoring action rules. The
first rule that's supported is a "source change" rule that returns a set of
atomic changes. This patch is based on the ideas presented in my RFC:

http://lists.llvm.org/pipermail/cfe-dev/2017-July/054831.html

The following pieces from the RFC are added by this patch:

- `createRefactoringRule` (known as `apply` in the RFC)
- `requiredSelection` refactoring action rule requirement.
- `selection::SourceSelectionRange` selection constraint.

Differential Revision: https://reviews.llvm.org/D36075

llvm-svn: 311884

2 files changed, 24 insertions, 0 deletions

diff --git a/clang/lib/Tooling/Refactoring/CMakeLists.txt b/clang/lib/Tooling/Refactoring/CMakeLists.txt
index 55e46ee3473..b0b66f16f6d 100644
--- a/clang/lib/Tooling/Refactoring/CMakeLists.txt
+++ b/clang/lib/Tooling/Refactoring/CMakeLists.txt
@@ -8,6 +8,7 @@ add_clang_library(clangToolingRefactor
   Rename/USRFinder.cpp
   Rename/USRFindingAction.cpp
   Rename/USRLocFinder.cpp
+  SourceSelectionConstraints.cpp
 
   LINK_LIBS
   clangAST
diff --git a/clang/lib/Tooling/Refactoring/SourceSelectionConstraints.cpp b/clang/lib/Tooling/Refactoring/SourceSelectionConstraints.cpp
new file mode 100644
index 00000000000..5fbe2946a9d
--- /dev/null
+++ b/clang/lib/Tooling/Refactoring/SourceSelectionConstraints.cpp
@@ -0,0 +1,23 @@
+//===--- SourceSelectionConstraints.cpp - Evaluate selection constraints --===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Tooling/Refactoring/SourceSelectionConstraints.h"
+#include "clang/Tooling/Refactoring/RefactoringRuleContext.h"
+
+using namespace clang;
+using namespace tooling;
+using namespace selection;
+
+Optional<SourceSelectionRange>
+SourceSelectionRange::evaluate(RefactoringRuleContext &Context) {
+  SourceRange R = Context.getSelectionRange();
+  if (R.isInvalid())
+    return None;
+  return SourceSelectionRange(Context.getSources(), R);
+}