From 4eaf46aeff9d8db559a77b09fb0b63de65a030ba Mon Sep 17 00:00:00 2001
From: Chinmay Garde <chinmaygarde@google.com>
Date: Wed, 27 Mar 2019 11:33:14 -0700
Subject: [PATCH] Reland "Allow specification of std::functions as native
 entrypoints from Dart code."

This reverts commit 7e77d5c484a08cc1c189619e80ae71a7f1df62fb after fixing Windows issues.
---
 .../embedder/fixtures/simple_main.dart        | 12 ++++++
 .../embedder/tests/embedder_context.h         | 12 ++++++
 .../embedder/tests/embedder_unittests.cc      | 40 +++++++++++++++++++
 3 files changed, 64 insertions(+)

diff --git a/shell/platform/embedder/fixtures/simple_main.dart b/shell/platform/embedder/fixtures/simple_main.dart
index b1124b508b7e3..bd3999563e031 100644
--- a/shell/platform/embedder/fixtures/simple_main.dart
+++ b/shell/platform/embedder/fixtures/simple_main.dart
@@ -6,3 +6,15 @@ void customEntrypoint() {
 }
 
 void sayHiFromCustomEntrypoint() native "SayHiFromCustomEntrypoint";
+
+
+@pragma('vm:entry-point')
+void customEntrypoint1() {
+  sayHiFromCustomEntrypoint1();
+  sayHiFromCustomEntrypoint2();
+  sayHiFromCustomEntrypoint3();
+}
+
+void sayHiFromCustomEntrypoint1() native "SayHiFromCustomEntrypoint1";
+void sayHiFromCustomEntrypoint2() native "SayHiFromCustomEntrypoint2";
+void sayHiFromCustomEntrypoint3() native "SayHiFromCustomEntrypoint3";
diff --git a/shell/platform/embedder/tests/embedder_context.h b/shell/platform/embedder/tests/embedder_context.h
index 6405163d9cd6a..cf31140d40029 100644
--- a/shell/platform/embedder/tests/embedder_context.h
+++ b/shell/platform/embedder/tests/embedder_context.h
@@ -16,11 +16,23 @@
 #include "flutter/shell/platform/embedder/embedder.h"
 #include "flutter/shell/platform/embedder/tests/embedder_test_resolver.h"
 
+#define CREATE_NATIVE_ENTRY(native_entry)                                   \
+  ([&]() {                                                                  \
+    static ::shell::testing::EmbedderContext::NativeEntry closure;          \
+    static Dart_NativeFunction entrypoint = [](Dart_NativeArguments args) { \
+      closure(args);                                                        \
+    };                                                                      \
+    closure = (native_entry);                                               \
+    return entrypoint;                                                      \
+  })()
+
 namespace shell {
 namespace testing {
 
 class EmbedderContext {
  public:
+  using NativeEntry = std::function<void(Dart_NativeArguments)>;
+
   EmbedderContext(std::string assets_path = "");
 
   ~EmbedderContext();
diff --git a/shell/platform/embedder/tests/embedder_unittests.cc b/shell/platform/embedder/tests/embedder_unittests.cc
index 01d23ff0d885f..6bad99a39dd0c 100644
--- a/shell/platform/embedder/tests/embedder_unittests.cc
+++ b/shell/platform/embedder/tests/embedder_unittests.cc
@@ -59,5 +59,45 @@ TEST_F(EmbedderTest, CanInvokeCustomEntrypoint) {
   ASSERT_TRUE(engine.is_valid());
 }
 
+TEST_F(EmbedderTest, CanInvokeCustomEntrypointMacro) {
+  auto& context = GetEmbedderContext();
+
+  fml::AutoResetWaitableEvent latch1;
+  fml::AutoResetWaitableEvent latch2;
+  fml::AutoResetWaitableEvent latch3;
+
+  // Can be defined separately.
+  auto entry1 = [&latch1](Dart_NativeArguments args) {
+    FML_LOG(ERROR) << "In Callback 1";
+    latch1.Signal();
+  };
+  auto native_entry1 = CREATE_NATIVE_ENTRY(entry1);
+  context.AddNativeCallback("SayHiFromCustomEntrypoint1", native_entry1);
+
+  // Can be wrapped in in the args.
+  auto entry2 = [&latch2](Dart_NativeArguments args) {
+    FML_LOG(ERROR) << "In Callback 2";
+    latch2.Signal();
+  };
+  context.AddNativeCallback("SayHiFromCustomEntrypoint2",
+                            CREATE_NATIVE_ENTRY(entry2));
+
+  // Everything can be inline.
+  context.AddNativeCallback(
+      "SayHiFromCustomEntrypoint3",
+      CREATE_NATIVE_ENTRY([&latch3](Dart_NativeArguments args) {
+        FML_LOG(ERROR) << "In Callback 3";
+        latch3.Signal();
+      }));
+
+  EmbedderConfigBuilder builder(context);
+  builder.SetDartEntrypoint("customEntrypoint1");
+  auto engine = builder.LaunchEngine();
+  latch1.Wait();
+  latch2.Wait();
+  latch3.Wait();
+  ASSERT_TRUE(engine.is_valid());
+}
+
 }  // namespace testing
 }  // namespace shell