Add a macro for prefixing embedder.h symbols (#9851)

embedder.h is a C API, so has no namespace, and only uses 'Flutter' as a prefix for most symbol names. This creates potential collisions with other code; for instance, FlutterEngine is the name of a type in embedder.h, but also an ObjC class in the iOS Flutter API. This adds a macro that can be set to prefix symbol names, allowing clients (notably, the macOS embedding) to adjust the names used by the embedding API internally without breaking ABI or API compatibility for the standard engine build. Currently the macro is only applied to FlutterEngine, since that's the symbol that is currently at issue, but it can be expanded to other symbols in the future.
flutter · Jul 23, 2019 · 7d320c4 · 7d320c4
1 parent 1f30131
commit 7d320c4
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Showing 8 changed files with 141 additions and 100 deletions.
diff --git a/shell/platform/common/cpp/BUILD.gn b/shell/platform/common/cpp/BUILD.gn
@@ -46,7 +46,7 @@ source_set("common_cpp") {
   deps = [
     ":common_cpp_library_headers",
     "$flutter_root/shell/platform/common/cpp/client_wrapper:client_wrapper",
-    "$flutter_root/shell/platform/embedder:embedder",
+    "$flutter_root/shell/platform/embedder:embedder_with_symbol_prefix",
   ]
 
   # TODO: Remove once text input model refactor lands, at which point this code

diff --git a/shell/platform/darwin/macos/BUILD.gn b/shell/platform/darwin/macos/BUILD.gn
@@ -65,7 +65,7 @@ shared_library("create_flutter_framework_dylib") {
 
   deps = [
     "$flutter_root/shell/platform/darwin/common:framework_shared",
-    "$flutter_root/shell/platform/embedder:embedder",
+    "$flutter_root/shell/platform/embedder:embedder_with_symbol_prefix",
   ]
 
   public_configs = [ "$flutter_root:config" ]

diff --git a/shell/platform/darwin/macos/framework/Source/FLEEngine.mm b/shell/platform/darwin/macos/framework/Source/FLEEngine.mm
@@ -123,7 +123,7 @@ static void OnPlatformMessage(const FlutterPlatformMessage* message, FLEEngine*
 
 @implementation FLEEngine {
   // The embedding-API-level engine object.
-  FlutterEngine _engine;
+  FLUTTER_API_SYMBOL(FlutterEngine) _engine;
 
   // The project being run by this engine.
   FLEDartProject* _project;

diff --git a/shell/platform/embedder/BUILD.gn b/shell/platform/embedder/BUILD.gn
@@ -14,49 +14,67 @@ shell_gpu_configuration("embedder_gpu_configuration") {
   enable_metal = false
 }
 
-source_set("embedder") {
-  sources = [
-    "embedder.cc",
-    "embedder.h",
-    "embedder_engine.cc",
-    "embedder_engine.h",
-    "embedder_external_texture_gl.cc",
-    "embedder_external_texture_gl.h",
-    "embedder_include.c",
-    "embedder_platform_message_response.cc",
-    "embedder_platform_message_response.h",
-    "embedder_safe_access.h",
-    "embedder_surface.cc",
-    "embedder_surface.h",
-    "embedder_surface_gl.cc",
-    "embedder_surface_gl.h",
-    "embedder_surface_software.cc",
-    "embedder_surface_software.h",
-    "embedder_task_runner.cc",
-    "embedder_task_runner.h",
-    "embedder_thread_host.cc",
-    "embedder_thread_host.h",
-    "platform_view_embedder.cc",
-    "platform_view_embedder.h",
-    "vsync_waiter_embedder.cc",
-    "vsync_waiter_embedder.h",
-  ]
+# Template for the embedder build. Used to allow building it multiple times with
+# different flags.
+template("embedder_source_set") {
+  forward_variables_from(invoker, "*")
 
-  deps = [
-    ":embedder_gpu_configuration",
-    "$flutter_root/assets",
-    "$flutter_root/common",
-    "$flutter_root/flow",
-    "$flutter_root/fml",
-    "$flutter_root/lib/ui",
-    "$flutter_root/runtime:libdart",
-    "$flutter_root/shell/common",
-    "//third_party/dart/runtime/bin:dart_io_api",
-    "//third_party/skia",
-    "//third_party/tonic",
-  ]
+  source_set(target_name) {
+    sources = [
+      "embedder.cc",
+      "embedder.h",
+      "embedder_engine.cc",
+      "embedder_engine.h",
+      "embedder_external_texture_gl.cc",
+      "embedder_external_texture_gl.h",
+      "embedder_include.c",
+      "embedder_platform_message_response.cc",
+      "embedder_platform_message_response.h",
+      "embedder_safe_access.h",
+      "embedder_surface.cc",
+      "embedder_surface.h",
+      "embedder_surface_gl.cc",
+      "embedder_surface_gl.h",
+      "embedder_surface_software.cc",
+      "embedder_surface_software.h",
+      "embedder_task_runner.cc",
+      "embedder_task_runner.h",
+      "embedder_thread_host.cc",
+      "embedder_thread_host.h",
+      "platform_view_embedder.cc",
+      "platform_view_embedder.h",
+      "vsync_waiter_embedder.cc",
+      "vsync_waiter_embedder.h",
+    ]
 
-  public_configs = [ "$flutter_root:config" ]
+    deps = [
+      ":embedder_gpu_configuration",
+      "$flutter_root/assets",
+      "$flutter_root/common",
+      "$flutter_root/flow",
+      "$flutter_root/fml",
+      "$flutter_root/lib/ui",
+      "$flutter_root/runtime:libdart",
+      "$flutter_root/shell/common",
+      "//third_party/dart/runtime/bin:dart_io_api",
+      "//third_party/skia",
+      "//third_party/tonic",
+    ]
+
+    public_configs += [ "$flutter_root:config" ]
+  }
+}
+
+embedder_source_set("embedder") {
+  public_configs = []
+}
+
+embedder_source_set("embedder_with_symbol_prefix") {
+  public_configs = [ ":embedder_prefix_config" ]
+}
+
+config("embedder_prefix_config") {
+  defines = [ "FLUTTER_API_SYMBOL_PREFIX=Embedder" ]
 }
 
 test_fixtures("fixtures") {

diff --git a/shell/platform/embedder/embedder.cc b/shell/platform/embedder/embedder.cc
@@ -312,7 +312,8 @@ FlutterEngineResult FlutterEngineRun(size_t version,
                                      const FlutterRendererConfig* config,
                                      const FlutterProjectArgs* args,
                                      void* user_data,
-                                     FlutterEngine* engine_out) {
+                                     FLUTTER_API_SYMBOL(FlutterEngine) *
+                                         engine_out) {
   // Step 0: Figure out arguments for shell creation.
   if (version != FLUTTER_ENGINE_VERSION) {
     return LOG_EMBEDDER_ERROR(kInvalidLibraryVersion);
@@ -640,11 +641,13 @@ FlutterEngineResult FlutterEngineRun(size_t version,
   }
 
   // Finally! Release the ownership of the embedder engine to the caller.
-  *engine_out = reinterpret_cast<FlutterEngine>(embedder_engine.release());
+  *engine_out = reinterpret_cast<FLUTTER_API_SYMBOL(FlutterEngine)>(
+      embedder_engine.release());
   return kSuccess;
 }
 
-FlutterEngineResult FlutterEngineShutdown(FlutterEngine engine) {
+FlutterEngineResult FlutterEngineShutdown(FLUTTER_API_SYMBOL(FlutterEngine)
+                                              engine) {
   if (engine == nullptr) {
     return LOG_EMBEDDER_ERROR(kInvalidArguments);
   }
@@ -655,7 +658,7 @@ FlutterEngineResult FlutterEngineShutdown(FlutterEngine engine) {
 }
 
 FlutterEngineResult FlutterEngineSendWindowMetricsEvent(
-    FlutterEngine engine,
+    FLUTTER_API_SYMBOL(FlutterEngine) engine,
     const FlutterWindowMetricsEvent* flutter_metrics) {
   if (engine == nullptr || flutter_metrics == nullptr) {
     return LOG_EMBEDDER_ERROR(kInvalidArguments);
@@ -742,7 +745,7 @@ inline int64_t PointerDataButtonsForLegacyEvent(
 }
 
 FlutterEngineResult FlutterEngineSendPointerEvent(
-    FlutterEngine engine,
+    FLUTTER_API_SYMBOL(FlutterEngine) engine,
     const FlutterPointerEvent* pointers,
     size_t events_count) {
   if (engine == nullptr || pointers == nullptr || events_count == 0) {
@@ -801,7 +804,7 @@ FlutterEngineResult FlutterEngineSendPointerEvent(
 }
 
 FlutterEngineResult FlutterEngineSendPlatformMessage(
-    FlutterEngine engine,
+    FLUTTER_API_SYMBOL(FlutterEngine) engine,
     const FlutterPlatformMessage* flutter_message) {
   if (engine == nullptr || flutter_message == nullptr) {
     return LOG_EMBEDDER_ERROR(kInvalidArguments);
@@ -844,7 +847,7 @@ FlutterEngineResult FlutterEngineSendPlatformMessage(
 }
 
 FlutterEngineResult FlutterPlatformMessageCreateResponseHandle(
-    FlutterEngine engine,
+    FLUTTER_API_SYMBOL(FlutterEngine) engine,
     FlutterDataCallback data_callback,
     void* user_data,
     FlutterPlatformMessageResponseHandle** response_out) {
@@ -875,7 +878,7 @@ FlutterEngineResult FlutterPlatformMessageCreateResponseHandle(
 }
 
 FlutterEngineResult FlutterPlatformMessageReleaseResponseHandle(
-    FlutterEngine engine,
+    FLUTTER_API_SYMBOL(FlutterEngine) engine,
     FlutterPlatformMessageResponseHandle* response) {
   if (engine == nullptr || response == nullptr) {
     return LOG_EMBEDDER_ERROR(kInvalidArguments);
@@ -885,7 +888,7 @@ FlutterEngineResult FlutterPlatformMessageReleaseResponseHandle(
 }
 
 FlutterEngineResult FlutterEngineSendPlatformMessageResponse(
-    FlutterEngine engine,
+    FLUTTER_API_SYMBOL(FlutterEngine) engine,
     const FlutterPlatformMessageResponseHandle* handle,
     const uint8_t* data,
     size_t data_length) {
@@ -915,7 +918,7 @@ FlutterEngineResult __FlutterEngineFlushPendingTasksNow() {
 }
 
 FlutterEngineResult FlutterEngineRegisterExternalTexture(
-    FlutterEngine engine,
+    FLUTTER_API_SYMBOL(FlutterEngine) engine,
     int64_t texture_identifier) {
   if (engine == nullptr || texture_identifier == 0) {
     return LOG_EMBEDDER_ERROR(kInvalidArguments);
@@ -928,7 +931,7 @@ FlutterEngineResult FlutterEngineRegisterExternalTexture(
 }
 
 FlutterEngineResult FlutterEngineUnregisterExternalTexture(
-    FlutterEngine engine,
+    FLUTTER_API_SYMBOL(FlutterEngine) engine,
     int64_t texture_identifier) {
   if (engine == nullptr || texture_identifier == 0) {
     return kInvalidArguments;
@@ -943,7 +946,7 @@ FlutterEngineResult FlutterEngineUnregisterExternalTexture(
 }
 
 FlutterEngineResult FlutterEngineMarkExternalTextureFrameAvailable(
-    FlutterEngine engine,
+    FLUTTER_API_SYMBOL(FlutterEngine) engine,
     int64_t texture_identifier) {
   if (engine == nullptr || texture_identifier == 0) {
     return LOG_EMBEDDER_ERROR(kInvalidArguments);
@@ -955,8 +958,9 @@ FlutterEngineResult FlutterEngineMarkExternalTextureFrameAvailable(
   return kSuccess;
 }
 
-FlutterEngineResult FlutterEngineUpdateSemanticsEnabled(FlutterEngine engine,
-                                                        bool enabled) {
+FlutterEngineResult FlutterEngineUpdateSemanticsEnabled(
+    FLUTTER_API_SYMBOL(FlutterEngine) engine,
+    bool enabled) {
   if (engine == nullptr) {
     return LOG_EMBEDDER_ERROR(kInvalidArguments);
   }
@@ -968,7 +972,7 @@ FlutterEngineResult FlutterEngineUpdateSemanticsEnabled(FlutterEngine engine,
 }
 
 FlutterEngineResult FlutterEngineUpdateAccessibilityFeatures(
-    FlutterEngine engine,
+    FLUTTER_API_SYMBOL(FlutterEngine) engine,
     FlutterAccessibilityFeature flags) {
   if (engine == nullptr) {
     return LOG_EMBEDDER_ERROR(kInvalidArguments);
@@ -981,7 +985,7 @@ FlutterEngineResult FlutterEngineUpdateAccessibilityFeatures(
 }
 
 FlutterEngineResult FlutterEngineDispatchSemanticsAction(
-    FlutterEngine engine,
+    FLUTTER_API_SYMBOL(FlutterEngine) engine,
     uint64_t id,
     FlutterSemanticsAction action,
     const uint8_t* data,
@@ -999,7 +1003,8 @@ FlutterEngineResult FlutterEngineDispatchSemanticsAction(
   return kSuccess;
 }
 
-FlutterEngineResult FlutterEngineOnVsync(FlutterEngine engine,
+FlutterEngineResult FlutterEngineOnVsync(FLUTTER_API_SYMBOL(FlutterEngine)
+                                             engine,
                                          intptr_t baton,
                                          uint64_t frame_start_time_nanos,
                                          uint64_t frame_target_time_nanos) {
@@ -1035,9 +1040,10 @@ void FlutterEngineTraceEventInstant(const char* name) {
   fml::tracing::TraceEventInstant0("flutter", name);
 }
 
-FlutterEngineResult FlutterEnginePostRenderThreadTask(FlutterEngine engine,
-                                                      VoidCallback callback,
-                                                      void* baton) {
+FlutterEngineResult FlutterEnginePostRenderThreadTask(
+    FLUTTER_API_SYMBOL(FlutterEngine) engine,
+    VoidCallback callback,
+    void* baton) {
   if (engine == nullptr || callback == nullptr) {
     return LOG_EMBEDDER_ERROR(kInvalidArguments);
   }
@@ -1054,7 +1060,8 @@ uint64_t FlutterEngineGetCurrentTime() {
   return fml::TimePoint::Now().ToEpochDelta().ToNanoseconds();
 }
 
-FlutterEngineResult FlutterEngineRunTask(FlutterEngine engine,
+FlutterEngineResult FlutterEngineRunTask(FLUTTER_API_SYMBOL(FlutterEngine)
+                                             engine,
                                          const FlutterTask* task) {
   if (engine == nullptr) {
     return LOG_EMBEDDER_ERROR(kInvalidArguments);