Gradle building issue

Question

I try to compile my project with native c-libs and get next error

/Users/eugene/KREF14001/app/src/main/jni/libC/PulseFilter.c: In function 'shapeMonoGame':
/Users/eugene/KREF14001/app/src/main/jni/libC/PulseFilter.c:696:5: error: 'for' loop initial declarations are only allowed in C99 mode
/Users/eugene/KREF14001/app/src/main/jni/libC/PulseFilter.c:696:5: note: use option -std=c99 or -std=gnu99 to compile your code

From this report I find that I must to use option -std=c99 or -std=gnu99 to compile my code, but I don't know how to do it. Please, help me.

Answer 1

In the build.gradle file of your app, you can add cFlags "-std=c99" in the ndk block located within the defaultConfig block like this:

ndk {
    moduleName "libblur"
    abiFilter "armeabi-v7a"
    stl "gnustl_static"
    cFlags "-std=c99"
    ldLibs "log"
}

Answer 2

The problem was in that the Gradle don't use your .mk files, but generate its own and use them. So it's useful to edit Android.mk and Application.mk. You can build your source code manually or edit ndk section of build.gradle.