[SourceKit] Introduce RawCharSourceRange

Use this to simplify the writing of ranges into
SourceKit responses.

Author: hamishknight

tools/SourceKit/include/SourceKit/Core/LangSupport.h

@@ -215,11 +215,18 @@ enum class DiagnosticCategory {
   NoUsage
 };
 
+struct RawCharSourceRange {
+  unsigned Offset;
+  unsigned Length;
+};
+
 struct DiagnosticEntryInfoBase {
   struct Fixit {
-    unsigned Offset;
-    unsigned Length;
+    RawCharSourceRange Range;
     std::string Text;
+
+    Fixit(RawCharSourceRange Range, std::string Text)
+        : Range(Range), Text(std::move(Text)) {}
   };
 
   std::string ID;
@@ -229,7 +236,7 @@ struct DiagnosticEntryInfoBase {
   unsigned Column = 0;
   std::string Filename;
   SmallVector<DiagnosticCategory, 1> Categories;
-  SmallVector<std::pair<unsigned, unsigned>, 2> Ranges;
+  SmallVector<RawCharSourceRange, 2> Ranges;
   SmallVector<Fixit, 2> Fixits;
   SmallVector<std::string, 1> EducationalNotePaths;
 };

tools/SourceKit/tools/sourcekitd/lib/Service/Requests.cpp

@@ -3514,6 +3514,12 @@ void SKEditorConsumer::recordFormattedText(StringRef Text) {
   Dict.set(KeySourceText, Text);
 }
 
+static void fillDictionaryForRange(ResponseBuilder::Dictionary Elem,
+                                   const RawCharSourceRange &R) {
+  Elem.set(KeyOffset, R.Offset);
+  Elem.set(KeyLength, R.Length);
+}
+
 static void fillDictionaryForDiagnosticInfoBase(
     ResponseBuilder::Dictionary Elem, const DiagnosticEntryInfoBase &Info) {
 
@@ -3554,19 +3560,15 @@ static void fillDictionaryForDiagnosticInfoBase(
 
   if (!Info.Ranges.empty()) {
     auto RangesArr = Elem.setArray(KeyRanges);
-    for (auto R : Info.Ranges) {
-      auto RangeElem = RangesArr.appendDictionary();
-      RangeElem.set(KeyOffset, R.first);
-      RangeElem.set(KeyLength, R.second);
-    }
+    for (auto R : Info.Ranges)
+      fillDictionaryForRange(RangesArr.appendDictionary(), R);
   }
 
   if (!Info.Fixits.empty()) {
     auto FixitsArr = Elem.setArray(KeyFixits);
     for (auto F : Info.Fixits) {
       auto FixitElem = FixitsArr.appendDictionary();
-      FixitElem.set(KeyOffset, F.Offset);
-      FixitElem.set(KeyLength, F.Length);
+      fillDictionaryForRange(FixitElem, F.Range);
       FixitElem.set(KeySourceText, F.Text);
     }
   }