From f77ab4fea6220d803b6b54dcab84e2105a8d0f28 Mon Sep 17 00:00:00 2001
From: Edward Chen <18449977+edgchen1@users.noreply.github.com>
Date: Mon, 1 Aug 2022 12:49:03 -0700
Subject: [PATCH] Manually add optimization flag for Android Release builds.
 (#12390)

With recent versions of NDK (since 23), the `-O` optimization level compile flag is not being passed when building in the "Release" configuration.
More details here: https://github.com/android/ndk/issues/1740

Our "Release" Android builds have been built without the optimization flag since we upgraded from NDK 21.

This change is a workaround to manually add `-O3` for "Release" Android builds.
---
 cmake/CMakeLists.txt | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/cmake/CMakeLists.txt b/cmake/CMakeLists.txt
index cb09051936..2395641eb5 100644
--- a/cmake/CMakeLists.txt
+++ b/cmake/CMakeLists.txt
@@ -318,6 +318,16 @@ if (onnxruntime_EXTENDED_MINIMAL_BUILD AND NOT onnxruntime_MINIMAL_BUILD)
   set(onnxruntime_MINIMAL_BUILD ON)
 endif()
 
+# work around Android NDK bug which doesn't include -O flag for Release configuration
+# https://github.com/android/ndk/issues/1740
+# TODO: remove this when the NDK version(s) we support get fixed
+if (CMAKE_SYSTEM_NAME STREQUAL "Android")
+  # NB: attempting to match the effects of this fix: https://android-review.googlesource.com/c/platform/ndk/+/2168845
+  string(APPEND CMAKE_C_FLAGS_RELEASE " -O3")
+  string(APPEND CMAKE_CXX_FLAGS_RELEASE " -O3")
+  string(APPEND CMAKE_ASM_FLAGS_RELEASE " -O3")
+endif()
+
 # Enable space optimization for gcc/clang
 # Cannot use "-ffunction-sections -fdata-sections" if we enable bitcode (iOS)
 if (NOT MSVC AND NOT onnxruntime_ENABLE_BITCODE)