[refactor] Initial outline of implementation of "extract function" refactoring

This commit adds an initial, skeleton outline of the "extract function"
refactoring. The extracted function doesn't capture variables / rewrite code
yet, it just basically does a simple copy-paste.
The following initiation rules are specified:

- extraction can only be done for executable code in a function/method/block.
  This means that you can't extract a global variable initialize into a function
  right now.
- simple literals and references are not extractable.

This commit also adds support for full source ranges to clang-refactor's test
mode.

Differential Revision: https://reviews.llvm.org/D38982


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@316465 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 37 insertions, 0 deletions

diff --git a/lib/Tooling/Refactoring/ASTSelection.cpp b/lib/Tooling/Refactoring/ASTSelection.cpp
index 2c9c42bfcb..9d0683a285 100644
--- a/lib/Tooling/Refactoring/ASTSelection.cpp
+++ b/lib/Tooling/Refactoring/ASTSelection.cpp
@@ -322,6 +322,10 @@ CodeRangeASTSelection::create(SourceRange SelectionRange,
     return CodeRangeASTSelection(Selected.Node, Selected.Parents,
                                  /*AreChildrenSelected=*/false);
   }
+  // FIXME (Alex L): First selected SwitchCase means that first case statement.
+  // is selected actually
+  // (See https://github.com/apple/swift-clang & CompoundStmtRange).
+
   // FIXME (Alex L): Tweak selection rules for compound statements, see:
   // https://github.com/apple/swift-clang/blob/swift-4.1-branch/lib/Tooling/
   // Refactor/ASTSlice.cpp#L513
@@ -330,3 +334,36 @@ CodeRangeASTSelection::create(SourceRange SelectionRange,
   return CodeRangeASTSelection(Selected.Node, Selected.Parents,
                                /*AreChildrenSelected=*/true);
 }
+
+bool CodeRangeASTSelection::isInFunctionLikeBodyOfCode() const {
+  bool IsPrevCompound = false;
+  // Scan through the parents (bottom-to-top) and check if the selection is
+  // contained in a compound statement that's a body of a function/method
+  // declaration.
+  for (const auto &Parent : llvm::reverse(Parents)) {
+    const DynTypedNode &Node = Parent.get().Node;
+    if (const auto *D = Node.get<Decl>()) {
+      // FIXME (Alex L): Test for BlockDecl && ObjCMethodDecl.
+      if (isa<FunctionDecl>(D))
+        return IsPrevCompound;
+      // FIXME (Alex L): We should return false on top-level decls in functions
+      // e.g. we don't want to extract:
+      // function foo() { struct X {
+      //   int m = /*selection:*/ 1 + 2 /*selection end*/; }; };
+    }
+    IsPrevCompound = Node.get<CompoundStmt>() != nullptr;
+  }
+  return false;
+}
+
+const Decl *CodeRangeASTSelection::getFunctionLikeNearestParent() const {
+  for (const auto &Parent : llvm::reverse(Parents)) {
+    const DynTypedNode &Node = Parent.get().Node;
+    if (const auto *D = Node.get<Decl>()) {
+      // FIXME (Alex L): Test for BlockDecl && ObjCMethodDecl.
+      if (isa<FunctionDecl>(D))
+        return D;
+    }
+  }
+  return nullptr;
+}