[SourceKit] Expose the data variant sourcekitd apis in the SwiftLang wrapper

These were recently added to support returning the SyntaxTree in the bytetree
from SourceKit but were never added in SwiftLang (the Swift layer wrapping
SourceKit).

Author: Nathan Hawes

tools/SourceKit/tools/swift-lang/CMakeLists.txt

@@ -13,7 +13,7 @@ if(NOT SWIFT_SOURCEKIT_USE_INPROC_LIBRARY AND SWIFT_BUILD_STDLIB)
     UIDs.swift.gyb
 
     DEPENDS ${DEPENDS_LIST}
-    SWIFT_MODULE_DEPENDS_OSX Darwin
+    SWIFT_MODULE_DEPENDS_OSX Darwin Foundation
     PRIVATE_LINK_LIBRARIES ${SOURCEKITD_LINK_LIBS}
     SWIFT_COMPILE_FLAGS ${EXTRA_COMPILE_FLAGS}
     INSTALL_IN_COMPONENT ${INSTALLED_COMP}

tools/SourceKit/tools/swift-lang/SourceKitdResponse.swift

@@ -12,6 +12,7 @@
 // This file provides convenient APIs to interpret a SourceKitd response.
 //===----------------------------------------------------------------------===//
 
+import Foundation
 import sourcekitd
 
 public class SourceKitdResponse: CustomStringConvertible {
@@ -60,6 +61,15 @@ public class SourceKitdResponse: CustomStringConvertible {
       return Dictionary(dict: value, context: context)
     }
 
+    public func getData(_ key: SourceKitdUID) -> Data {
+      let value = sourcekitd_variant_dictionary_get_value(dict, key.uid)
+      let size = sourcekitd_variant_data_get_size(value)
+      guard let ptr = sourcekitd_variant_data_get_ptr(value), size > 0 else {
+        return Data()
+      }
+      return Data(bytes: ptr, count: size)
+    }
+
     public func getOptional(_ key: SourceKitdUID) -> Variant? {
       let value = sourcekitd_variant_dictionary_get_value(dict, key.uid)
       if sourcekitd_variant_get_type(value).rawValue ==
@@ -188,6 +198,14 @@ public class SourceKitdResponse: CustomStringConvertible {
       return Dictionary(dict: val, context: context)
     }
 
+    public func getData() -> Data {
+      let size = sourcekitd_variant_data_get_size(val)
+      guard let ptr = sourcekitd_variant_data_get_ptr(val), size > 0 else {
+        return Data()
+      }
+      return Data(bytes: ptr, count: size)
+    }
+
     public var description: String {
       return val.description
     }