PrintAsObjC: Support for blocks with __owned parameters

Author: slavapestov

lib/PrintAsObjC/DeclAndTypePrinter.cpp

@@ -1934,7 +1934,18 @@ class DeclAndTypePrinter::Implementation
     if (!FT->getParams().empty()) {
       interleave(FT->getParams(),
                  [this](const AnyFunctionType::Param &param) {
-                   print(param.getOldType(), OTK_None, param.getLabel(),
+                   switch (param.getValueOwnership()) {
+                   case ValueOwnership::Default:
+                   case ValueOwnership::Shared:
+                     break;
+                   case ValueOwnership::Owned:
+                     os << "SWIFT_RELEASES_ARGUMENT ";
+                     break;
+                   case ValueOwnership::InOut:
+                     llvm_unreachable("bad specifier");
+                   }
+
+                   print(param.getParameterType(), OTK_None, param.getLabel(),
                          IsFunctionParam);
                  },
                  [this] { os << ", "; });

lib/PrintAsObjC/PrintAsObjC.cpp

@@ -112,6 +112,11 @@ static void writePrologue(raw_ostream &out, ASTContext &ctx) {
          "#else\n"
          "# define SWIFT_NOESCAPE\n"
          "#endif\n"
+         "#if __has_attribute(ns_consumed)\n"
+         "# define SWIFT_RELEASES_ARGUMENT __attribute__((ns_consumed))\n"
+         "#else\n"
+         "# define SWIFT_RELEASES_ARGUMENT\n"
+         "#endif\n"
          "#if __has_attribute(warn_unused_result)\n"
          "# define SWIFT_WARN_UNUSED_RESULT __attribute__((warn_unused_result))\n"
          "#else\n"

test/PrintAsObjC/blocks.swift

@@ -113,6 +113,9 @@ typealias MyBlockWithNoescapeParam = (() -> ()) -> Int
     return input
   }
 
+  // CHECK-NEXT: - (void)blockWithConsumingArgument:(void (^ _Nonnull)(SWIFT_RELEASES_ARGUMENT NSObject * _Nonnull))block;
+  @objc func blockWithConsumingArgument(_ block: @escaping (__owned NSObject) -> ()) {}
+
   // CHECK-NEXT: @property (nonatomic, copy) NSInteger (^ _Nullable savedBlock)(NSInteger);
   @objc var savedBlock: ((Int) -> Int)?