Android studio doesn't appear to be reading .mk files

Question

I am using Android Studio 1.3 with the experimental ndk plugin enabled. I am trying to compile Box2d by placing the Box2d folder into the jni folder. I have Android.mk and Application.mk in there as well. Whenever I try to compile Android studio spits out errors that the header files cannot be found. It seems that no matter what I do to the .mk files nothing changes. It's like they are not even being read. Does Android studio read .mk files?

LOCAL_PATH:=$(call my-dir)
$(info $(LOCAL_PATH))
source_directories:=\
    Collision \
    Collision/Shapes \
    Common \
    Dynamics \
    Dynamics/Contacts \
    Dynamics/Joints \
    Particle \
    Rope

include $(LOCAL_PATH)/b2_android_common.mk

# Conditionally include libstlport (so include path is added to CFLAGS) if
# it's not being built using the NDK build process.
define add-stlport-includes
$(eval \
  ifeq ($(NDK_PROJECT_PATH),)
  include external/stlport/libstlport.mk
  endif)
endef

# Configure common local variables to build box2d adding $(1) to the end of the
# build target's name.
define box2d-module
$(eval \
  LOCAL_MODULE:=libliquidfun$(1)
  LOCAL_MODULE_TAGS:=optional
  LOCAL_COPY_HEADERS_TO:=liquidfun$(1))
endef

# Execute a shell command relative to this module's directory.
define execute-local
$(patsubst ./%,%,$(shell cd $(LOCAL_PATH) ; eval "$(1)"))
endef

# Configure local variables to build box2d adding $(1) to the end of the
# build target's name.
define box2d-build
$(eval \
  $$(call box2d-module,$(1))
  LOCAL_SRC_FILES:=\
    $(subst $(LOCAL_PATH)/,,\
      $(foreach source_dir,$(source_directories),\
        $(foreach extension,$(b2_extensions),\
          $(wildcard $(LOCAL_PATH)/Box2D/$(source_dir)/*.$(extension)))))
  LOCAL_COPY_HEADERS:=\
    Box2D/Box2D.h \
    $(subst $(LOCAL_PATH)/,,\
      $(foreach source_dir,$(source_directories),\
        $(wildcard $(LOCAL_PATH)/Box2D/$(source_dir)/*.h)))
  LOCAL_CFLAGS:=$(if $(APP_DEBUG),-DDEBUG=1,-DDEBUG=0) $(b2_cflags)
  LOCAL_EXPORT_C_INCLUDES:=$(LOCAL_PATH)
  LOCAL_ARM_MODE:=arm
  $$(call add-stlport-includes))
endef

# --- libliquidfun ---
# Build shared library.
include $(CLEAR_VARS)
$(call box2d-build,)
include $(BUILD_SHARED_LIBRARY)

# --- libliquidfun_static ---
# Build static library.
include $(CLEAR_VARS)
$(call box2d-build,_static)
include $(BUILD_STATIC_LIBRARY)

Answer 1

no, Android Studio doesn't read *.mk files.

It generates Makefiles automatically for all your source files that are under jni/, by following the configuration you can do inside build.gradle.

You can try making box2d compile this way. You'll have to write a configuration like this one:

android.ndk {
    //...
    stl = stlport_static
    cppFlags += "-I${file("src/main/jni/Box2D/Collision")}".toString() // extra includes
    //...
}

Else, if you want your Makefiles to be considered, you can call ndk-build yourself. Set this inside your build.gradle so it will not try to compile your code, and it will get your .so files from src/main/libs/:

android.sources{
    main.jni {
        source {
            srcDirs = ['src/main/none'] // [] could be set instead but will disable even symbol resolution inside the editor
        }
    }
    main.jniLibs {
        source {
            srcDirs = ['src/main/libs']
        }
    }
}