[Buildroot] [PATCH/next 2/7] package/flutter-engine: Add runtime mode choice

[Adam Duskett]

There are only two possible modes for Flutter: Debug and release. However,
there is a third mode available to users: profile.

As Flutter projects can be pretty heavy and consume a lot of resources, it is
necessary to allow users to profile their Flutter application during
development.

Add three new choices: FLUTTER_ENGINE_RUNTIME_MODE_{DEBUG,PROFILE,RELEASE}
and set release as the default.

Signed-off-by: Adam Duskett <adam.duskett at amarulasolutions.com>
---
 package/flutter-engine/Config.in         | 57 ++++++++++++++++++++++++
 package/flutter-engine/flutter-engine.mk |  4 +-
 2 files changed, 60 insertions(+), 1 deletion(-)

diff --git a/package/flutter-engine/Config.in b/package/flutter-engine/Config.in
index 2ec5b90ffd..5626e31756 100644
--- a/package/flutter-engine/Config.in
+++ b/package/flutter-engine/Config.in
@@ -39,6 +39,63 @@ config BR2_PACKAGE_FLUTTER_ENGINE
 
 	  https://github.com/flutter/engine
 
+if BR2_PACKAGE_FLUTTER_ENGINE
+
+choice
+	prompt "flutter-engine mode"
+	default FLUTTER_ENGINE_RUNTIME_MODE_DEBUG if BR2_ENABLE_RUNTIME_DEBUG
+	default FLUTTER_ENGINE_RUNTIME_MODE_RELEASE
+
+config FLUTTER_ENGINE_RUNTIME_MODE_DEBUG
+	bool "Debug"
+	help
+	  Uses just-in-time (JIT) compilation for faster compilation
+	  and debugging. This mode is also called check mode or slow
+	  mode. This allows hot reload.
+
+	  https://docs.flutter.dev/testing/build-modes#debug
+
+config FLUTTER_ENGINE_RUNTIME_MODE_PROFILE
+	bool "Profile"
+	help
+	  Some debugging ability is maintained—enough to profile your
+	  apps performance. Profile mode is disabled on the emulator
+	  and simulator, because their behavior is not representative
+	  of real performance. Profile mode is similar to release mode,
+	  with the following differences:
+
+	  - Some service extensions, such as the one that enables the
+	    performance overlay, are enabled.
+
+	  - Tracing is enabled, and tools supporting source-level
+	    debugging (such as DevTools) can connect to the process.
+
+	  https://docs.flutter.dev/testing/build-modes#profile
+
+config FLUTTER_ENGINE_RUNTIME_MODE_RELEASE
+	bool "Release"
+	help
+	  Use release mode for deploying the app, when you want maximum
+	  optimization and minimal footprint size. Release mode
+	  (which is not supported on the simulator or emulator), means
+	  that:
+
+	  - Assertions are disabled.
+
+	  - Debugging information is stripped out.
+
+	  - Debugging is disabled.
+
+	  - Compilation is optimized for fast startup, fast execution,
+	    and small package sizes.
+
+	  - Service extensions are disabled.
+
+	  https://docs.flutter.dev/testing/build-modes#release
+
+endchoice
+endif # BR2_PACKAGE_FLUTTER_ENGINE
+
 comment "flutter-engine needs an OpenGL or OpenGLES backend"
 	depends on BR2_PACKAGE_FLUTTER_ENGINE_ARCH_SUPPORTS
 	depends on !BR2_PACKAGE_HAS_LIBGL && !BR2_PACKAGE_HAS_LIBGLES
diff --git a/package/flutter-engine/flutter-engine.mk b/package/flutter-engine/flutter-engine.mk
index 32aaa1cccf..15a5c60fd1 100644
--- a/package/flutter-engine/flutter-engine.mk
+++ b/package/flutter-engine/flutter-engine.mk
@@ -52,8 +52,10 @@ FLUTTER_ENGINE_TARGET_ARCH = x64
 FLUTTER_ENGINE_TARGET_TRIPPLE = x86_64-unknown-linux-gnu
 endif
 
-ifeq ($(BR2_ENABLE_RUNTIME_DEBUG),y)
+ifeq ($(FLUTTER_ENGINE_RUNTIME_MODE_DEBUG),y)
 FLUTTER_ENGINE_RUNTIME_MODE=debug
+else ifeq ($(FLUTTER_ENGINE_RUNTIME_MODE_PROFILE),y)
+FLUTTER_ENGINE_RUNTIME_MODE=profile
 else
 FLUTTER_ENGINE_RUNTIME_MODE=release
 endif
-- 
2.42.0