draft

objc smart pointers support arc

fix license

add unittests

gn format

format

migrate VsyncWaiterIosTest.mm to arc

try build.gn fix

try build.gn fix

exclude tests from license file

fix license

BUILD.gn

@@ -160,6 +160,7 @@ group("unittests") {
       "//flutter/display_list:display_list_unittests",
       "//flutter/flow:flow_unittests",
       "//flutter/fml:fml_unittests",
+      "//flutter/fml:fml_unittests_arc",
       "//flutter/lib/ui:ui_unittests",
       "//flutter/runtime:dart_plugin_registrant_unittests",
       "//flutter/runtime:no_dart_plugin_registrant_unittests",

ci/licenses_golden/excluded_files

@@ -101,6 +101,8 @@
 ../../../flutter/fml/message_loop_unittests.cc
 ../../../flutter/fml/paths_unittests.cc
 ../../../flutter/fml/platform/darwin/cf_utils_unittests.mm
+../../../flutter/fml/platform/darwin/scoped_nsobject_unittests.mm
+../../../flutter/fml/platform/darwin/scoped_nsobject_unittests_arc.mm
 ../../../flutter/fml/platform/darwin/string_range_sanitization_unittests.mm
 ../../../flutter/fml/platform/win/file_win_unittests.cc
 ../../../flutter/fml/platform/win/wstring_conversion_unittests.cc

ci/licenses_golden/licenses_flutter

@@ -2795,6 +2795,8 @@ ORIGIN: ../../../flutter/fml/platform/darwin/scoped_nsautorelease_pool.cc + ../.
 ORIGIN: ../../../flutter/fml/platform/darwin/scoped_nsautorelease_pool.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/fml/platform/darwin/scoped_nsobject.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/fml/platform/darwin/scoped_nsobject.mm + ../../../flutter/LICENSE
+ORIGIN: ../../../flutter/fml/platform/darwin/scoped_policy.h + ../../../flutter/LICENSE
+ORIGIN: ../../../flutter/fml/platform/darwin/scoped_typeref.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/fml/platform/darwin/string_range_sanitization.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/fml/platform/darwin/string_range_sanitization.mm + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/fml/platform/fuchsia/message_loop_fuchsia.cc + ../../../flutter/LICENSE
@@ -5549,6 +5551,8 @@ FILE: ../../../flutter/fml/platform/darwin/scoped_nsautorelease_pool.cc
 FILE: ../../../flutter/fml/platform/darwin/scoped_nsautorelease_pool.h
 FILE: ../../../flutter/fml/platform/darwin/scoped_nsobject.h
 FILE: ../../../flutter/fml/platform/darwin/scoped_nsobject.mm
+FILE: ../../../flutter/fml/platform/darwin/scoped_policy.h
+FILE: ../../../flutter/fml/platform/darwin/scoped_typeref.h
 FILE: ../../../flutter/fml/platform/darwin/string_range_sanitization.h
 FILE: ../../../flutter/fml/platform/darwin/string_range_sanitization.mm
 FILE: ../../../flutter/fml/platform/fuchsia/message_loop_fuchsia.cc

fml/BUILD.gn

@@ -165,6 +165,8 @@ source_set("fml") {
       "platform/darwin/scoped_nsautorelease_pool.h",
       "platform/darwin/scoped_nsobject.h",
       "platform/darwin/scoped_nsobject.mm",
+      "platform/darwin/scoped_policy.h",
+      "platform/darwin/scoped_typeref.h",
       "platform/darwin/string_range_sanitization.h",
       "platform/darwin/string_range_sanitization.mm",
     ]
@@ -366,6 +368,10 @@ if (enable_unittests) {
       ]
     }
 
+    if (is_mac || is_ios) {
+      sources += [ "platform/darwin/scoped_nsobject_unittests.mm" ]
+    }
+
     if (is_win) {
       sources += [
         "platform/win/file_win_unittests.cc",
@@ -388,4 +394,18 @@ if (enable_unittests) {
           [ "${fuchsia_sdk_path}/arch/${target_cpu}/sysroot/lib/libzircon.so" ]
     }
   }
+
+  executable("fml_unittests_arc") {
+    testonly = true
+    if (is_mac || is_ios) {
+      cflags_objcc = flutter_cflags_objc_arc
+      sources = [ "platform/darwin/scoped_nsobject_unittests_arc.mm" ]
+    }
+
+    deps = [
+      ":fml_fixtures",
+      "//flutter/fml",
+      "//flutter/testing",
+    ]
+  }
 }

fml/compiler_specific.h

@@ -26,4 +26,14 @@
 #define FML_ALLOW_UNUSED_TYPE
 #endif
 
+// Annotate a function indicating the caller must examine the return value.
+// Use like:
+//   int foo() WARN_UNUSED_RESULT;
+#undef WARN_UNUSED_RESULT
+#if defined(COMPILER_GCC) || defined(__clang__)
+#define WARN_UNUSED_RESULT __attribute__((warn_unused_result))
+#else
+#define WARN_UNUSED_RESULT
+#endif
+
 #endif  // FLUTTER_FML_COMPILER_SPECIFIC_H_

fml/platform/darwin/scoped_block.h

@@ -8,86 +8,40 @@
 #include <Block.h>
 
 #include "flutter/fml/compiler_specific.h"
+#include "flutter/fml/platform/darwin/scoped_typeref.h"
 
-namespace fml {
-
-// ScopedBlock<> is patterned after ScopedCFTypeRef<>, but uses Block_copy() and
-// Block_release() instead of CFRetain() and CFRelease().
+#if defined(__has_feature) && __has_feature(objc_arc)
+#define BASE_MAC_BRIDGE_CAST(TYPE, VALUE) (__bridge TYPE)(VALUE)
+#else
+#define BASE_MAC_BRIDGE_CAST(TYPE, VALUE) VALUE
+#endif
 
-enum class OwnershipPolicy {
-  // The scoped object takes ownership of an object by taking over an existing
-  // ownership claim.
-  kAssume,
+namespace fml {
 
-  // The scoped object will retain the object and any initial ownership is
-  // not changed.
-  kRetain,
-};
+namespace internal {
 
 template <typename B>
-class ScopedBlock {
- public:
-  explicit ScopedBlock(B block = nullptr,
-                       OwnershipPolicy policy = OwnershipPolicy::kAssume)
-      : block_(block) {
-    if (block_ && policy == OwnershipPolicy::kRetain) {
-      block_ = Block_copy(block);
-    }
+struct ScopedBlockTraits {
+  static B InvalidValue() { return nullptr; }
+  static B Retain(B block) {
+    return BASE_MAC_BRIDGE_CAST(
+        B, Block_copy(BASE_MAC_BRIDGE_CAST(const void*, block)));
   }
-
-  ScopedBlock(const ScopedBlock<B>& that) : block_(that.block_) {
-    if (block_) {
-      block_ = Block_copy(block_);
-    }
-  }
-
-  ~ScopedBlock() {
-    if (block_) {
-      Block_release(block_);
-    }
-  }
-
-  ScopedBlock& operator=(const ScopedBlock<B>& that) {
-    reset(that.get(), OwnershipPolicy::kRetain);
-    return *this;
-  }
-
-  void reset(B block = nullptr,
-             OwnershipPolicy policy = OwnershipPolicy::kAssume) {
-    if (block && policy == OwnershipPolicy::kRetain) {
-      block = Block_copy(block);
-    }
-    if (block_) {
-      Block_release(block_);
-    }
-    block_ = block;
+  static void Release(B block) {
+    Block_release(BASE_MAC_BRIDGE_CAST(const void*, block));
   }
+};
 
-  bool operator==(B that) const { return block_ == that; }
-
-  bool operator!=(B that) const { return block_ != that; }
-
-  // NOLINTNEXTLINE(google-explicit-constructor)
-  operator B() const { return block_; }
-
-  B get() const { return block_; }
-
-  void swap(ScopedBlock& that) {
-    B temp = that.block_;
-    that.block_ = block_;
-    block_ = temp;
-  }
+}  // namespace internal
 
-  [[nodiscard]] B release() {
-    B temp = block_;
-    block_ = nullptr;
-    return temp;
-  }
+// ScopedBlock<> is patterned after ScopedCFTypeRef<>, but uses Block_copy() and
+// Block_release() instead of CFRetain() and CFRelease().
 
- private:
-  B block_;
-};
+template <typename B>
+using ScopedBlock = ScopedTypeRef<B, internal::ScopedBlockTraits<B>>;
 
 }  // namespace fml
 
+#undef BASE_MAC_BRIDGE_CAST
+
 #endif  // FLUTTER_FML_PLATFORM_DARWIN_SCOPED_BLOCK_H_