Android.mk, include all cpp files

You could try something like this...

FILE_LIST := $(wildcard $(LOCAL_PATH)/[DIRECTORY]/*.cpp)
LOCAL_SRC_FILES := $(FILE_LIST:$(LOCAL_PATH)/%=%)

... Change [DIRECTORY] to the actual directory of the files. If they are in the same directory as your .mk file then remove that part. Create the FILE_LIST variable to find all of the .cpp files under the [DIRECTORY] directory. Then use it in the file listing. The LOCAL_SRC_FILES line will then remove the LOCAL_PATH from the listing.

How about like this:

LOCAL_SRC_FILES := $(subst $(LOCAL_PATH)/,,$(wildcard $(LOCAL_PATH)/*.cpp))

If you'd be afraid that expansion of * contains $(LOCAL_PATH)/, it might be OK:

LOCAL_SRC_FILES := $(subst $(LOCAL_PATH)/./,,$(wildcard $(LOCAL_PATH)/./*.cpp))

I've been using this script for my Android.mk saved me so much time!

#traverse all the directory and subdirectory
define walk
  $(wildcard $(1)) $(foreach e, $(wildcard $(1)/*), $(call walk, $(e)))
endef

#find all the file recursively under jni/
ALLFILES = $(call walk, $(LOCAL_PATH))
FILE_LIST := $(filter %.cpp, $(ALLFILES))

LOCAL_SRC_FILES := $(FILE_LIST:$(LOCAL_PATH)/%=%)

Here is the gist