Android NDK 2020 C code - How to enable release mode with all optimizations

Issue

I see that people do this by changing their Android.mk and Application.mk files. However, I cannot find the file in my project at all. What I wish to do is to optimize the code as much as possible (in Visual Studio, Release mode can be 10x faster than Debug mode). How can I do this in android NDK ?

Thank you.

APP_OPTIM := release
ndk-build NDK_DEBUG=0
-DNDEBUG
LOCAL_CFLAGS += -O2

Solution

If you'd like to specify some options manually only in release configuration, append cppFlags to the relevant section in app/build.gradle as follows.

android {

    :

    buildTypes {
        release {
            // debuggable false
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'

            externalNativeBuild {
                cmake {
                    cppFlags += "-O2 -DNDEBUG"
                }
            }
        }
    }

    :
}

Answered By - ardget