[RenderEngine] Only compile Graphite if either Graphite flag is enabled

RE-Graphite will be *compiled* if either the graphite_renderengine
or force_compile_graphite_renderengine ready-only flag is enabled at
compile time (inclusive OR).

RE-Graphite can be compiled and *enabled* by:
1. setting just graphite_renderengine=true, or
2. setting both force_compile_graphite_renderengine=true and the
debug.renderengine.graphite system property to true.

Why RenderEngine needs a dep on libsurfaceflingerflags now:
libsurfaceflinger_common pulls in SF's FlagManager, which is layered on
top of the API that's autogenerated for SF's aconfig module,
libsurfaceflingerflags.
The COM_ANDROID_GRAPHICS_SURFACEFLINGER_FLAGS(...) macro is defined by
com_android_graphics_surfaceflinger_flags.h in that latter aconfig
module, and that header is not exported by the higher-level FlagManager
code.

Bug: b/293371537
Bug: b/331678326
Bug: b/341728634
Test: boot and bloaty (see b/331678326)
Flag: com.android.graphics.surfaceflinger.flags.graphite_renderengine
Change-Id: I9d0b15bda08430552716a9a1f7cd59d91ee7b9a6

1 files changed, 28 insertions, 3 deletions

diff --git a/libs/renderengine/RenderEngine.cpp b/libs/renderengine/RenderEngine.cpp
index 1c60563b25..bc3976d9f1 100644
--- a/libs/renderengine/RenderEngine.cpp
+++ b/libs/renderengine/RenderEngine.cpp
@@ -22,24 +22,49 @@
 #include "skia/SkiaGLRenderEngine.h"
 #include "threaded/RenderEngineThreaded.h"
 
+#include <com_android_graphics_surfaceflinger_flags.h>
 #include <cutils/properties.h>
 #include <log/log.h>
 
+// TODO: b/341728634 - Clean up conditional compilation.
+#if COM_ANDROID_GRAPHICS_SURFACEFLINGER_FLAGS(GRAPHITE_RENDERENGINE) || \
+        COM_ANDROID_GRAPHICS_SURFACEFLINGER_FLAGS(FORCE_COMPILE_GRAPHITE_RENDERENGINE)
+#define COMPILE_GRAPHITE_RENDERENGINE 1
+#else
+#define COMPILE_GRAPHITE_RENDERENGINE 0
+#endif
+
 namespace android {
 namespace renderengine {
 
 std::unique_ptr<RenderEngine> RenderEngine::create(const RenderEngineCreationArgs& args) {
     threaded::CreateInstanceFactory createInstanceFactory;
 
+// TODO: b/341728634 - Clean up conditional compilation.
+#if COMPILE_GRAPHITE_RENDERENGINE
+    const RenderEngine::SkiaBackend actualSkiaBackend = args.skiaBackend;
+#else
+    if (args.skiaBackend == RenderEngine::SkiaBackend::GRAPHITE) {
+        ALOGE("RenderEngine with Graphite Skia backend was requested, but Graphite was not "
+              "included in the build. Falling back to Ganesh (%s)",
+              args.graphicsApi == RenderEngine::GraphicsApi::GL ? "GL" : "Vulkan");
+    }
+    const RenderEngine::SkiaBackend actualSkiaBackend = RenderEngine::SkiaBackend::GANESH;
+#endif
+
     ALOGD("%sRenderEngine with %s Backend (%s)", args.threaded == Threaded::YES ? "Threaded " : "",
           args.graphicsApi == GraphicsApi::GL ? "SkiaGL" : "SkiaVK",
-          args.skiaBackend == SkiaBackend::GANESH ? "Ganesh" : "Graphite");
+          actualSkiaBackend == SkiaBackend::GANESH ? "Ganesh" : "Graphite");
 
-    if (args.skiaBackend == SkiaBackend::GRAPHITE) {
+// TODO: b/341728634 - Clean up conditional compilation.
+#if COMPILE_GRAPHITE_RENDERENGINE
+    if (actualSkiaBackend == SkiaBackend::GRAPHITE) {
         createInstanceFactory = [args]() {
             return android::renderengine::skia::GraphiteVkRenderEngine::create(args);
         };
-    } else { // GANESH
+    } else
+#endif
+    { // GANESH
         if (args.graphicsApi == GraphicsApi::VK) {
             createInstanceFactory = [args]() {
                 return android::renderengine::skia::GaneshVkRenderEngine::create(args);