Add source location requirement

Added source location requirement for refactoring engine

Author: Игнат Сергеев

clang/include/clang/Basic/DiagnosticRefactoringKinds.td

@@ -28,6 +28,8 @@ def err_refactor_extract_simple_expression : Error<"the selected expression "
 def err_refactor_extract_prohibited_expression : Error<"the selected "
   "expression can't be extracted">;
 
+def err_refactor_no_location : Error<"refactoring action can't be initiated "
+  "without a location">;
 }
 
 } // end of Refactoring diagnostics

clang/include/clang/Tooling/Refactoring/RefactoringActionRule.h

@@ -56,6 +56,10 @@ class RefactoringActionRule : public RefactoringActionRuleBase {
   /// to be fulfilled before refactoring can be performed.
   virtual bool hasSelectionRequirement() = 0;
 
+  /// Returns true when the rule has a source location requirement that has
+  /// to be fulfilled before refactoring can be performed.
+  virtual bool hasLocationRequirement() = 0;
+
   /// Traverses each refactoring option used by the rule and invokes the
   /// \c visit callback in the consumer for each option.
   ///

clang/include/clang/Tooling/Refactoring/RefactoringActionRuleRequirements.h

@@ -10,6 +10,7 @@
 #define LLVM_CLANG_TOOLING_REFACTORING_REFACTORINGACTIONRULEREQUIREMENTS_H
 
 #include "clang/Basic/LLVM.h"
+#include "clang/Basic/SourceLocation.h"
 #include "clang/Tooling/Refactoring/ASTSelection.h"
 #include "clang/Tooling/Refactoring/RefactoringDiagnostic.h"
 #include "clang/Tooling/Refactoring/RefactoringOption.h"
@@ -77,6 +78,17 @@ class CodeRangeASTSelectionRequirement : public ASTSelectionRequirement {
   evaluate(RefactoringRuleContext &Context) const;
 };
 
+/// A base class for any requirement that expects source code position (or the
+/// refactoring tool with the -location option).
+class SourceLocationRequirement : public RefactoringActionRuleRequirement {
+public:
+  Expected<SourceLocation> evaluate(RefactoringRuleContext &Context) const {
+    if (Context.getLocation().isValid())
+      return Context.getLocation();
+    return Context.createDiagnosticError(diag::err_refactor_no_location);
+  }
+};
+
 /// A base class for any requirement that requires some refactoring options.
 class RefactoringOptionsRequirement : public RefactoringActionRuleRequirement {
 public:

clang/include/clang/Tooling/Refactoring/RefactoringActionRulesInternal.h

@@ -139,6 +139,11 @@ createRefactoringActionRule(const RequirementTypes &... Requirements) {
                                  RequirementTypes...>::value;
     }
 
+    bool hasLocationRequirement() override {
+      return internal::HasBaseOf<SourceLocationRequirement,
+                                 RequirementTypes...>::value;
+    }
+
     void visitRefactoringOptions(RefactoringOptionVisitor &Visitor) override {
       internal::visitRefactoringOptions(
           Visitor, Requirements,

clang/include/clang/Tooling/Refactoring/RefactoringRuleContext.h

@@ -30,6 +30,9 @@ namespace tooling {
 ///
 ///   - SelectionRange: an optional source selection ranges that can be used
 ///     to represent a selection in an editor.
+///
+///   - Location: an optional source location that can be used
+///     to represent a cursor in an editor.
 class RefactoringRuleContext {
 public:
   RefactoringRuleContext(const SourceManager &SM) : SM(SM) {}
@@ -40,8 +43,14 @@ class RefactoringRuleContext {
   /// refactoring engine. Can be invalid.
   SourceRange getSelectionRange() const { return SelectionRange; }
 
+  /// Returns the current source location as set by the
+  /// refactoring engine. Can be invalid.
+  SourceLocation getLocation() const { return Location; }
+
   void setSelectionRange(SourceRange R) { SelectionRange = R; }
 
+  void setLocation(SourceLocation L) { Location = L; }
+
   bool hasASTContext() const { return AST; }
 
   ASTContext &getASTContext() const {
@@ -73,6 +82,9 @@ class RefactoringRuleContext {
   /// An optional source selection range that's commonly used to represent
   /// a selection in an editor.
   SourceRange SelectionRange;
+  /// An optional source location that's commonly used to represent
+  /// a cursor in an editor.
+  SourceLocation Location;
   /// An optional AST for the translation unit on which a refactoring action
   /// might operate on.
   ASTContext *AST = nullptr;