Android run shell script via makefile for every platform mentioned in APP_ABI

Question

I have a Android native application which builds for platform x86, armeabi and armeabi-v7a. Now depending upon whether the platform is x86 or arm, I need to run the script accordingly with the corresponding arguments so appropriate third party tool environment variables are set. I tried doing below:

.o.cpp:
      ifeq ($(TARGET_ARCH),x86)
            $(info $(shell ($(CACHE_LOCAL_PATH_MAIN)/setup_tool.sh x86)))
      else
            $(info $(shell ($(CACHE_LOCAL_PATH_MAIN)/setup_tool.sh arm)))
      endif

But the problem is, when the makefile is parsed, these scripts get run in the initial phase itself 3 times and not before compilation of every platform begins. Is there a way to get this fixed so the script gets run just before the compilation for every platform begins? Thanks.

UPDATED with Android.mk file:

LOCAL_PATH := $(call my-dir) 
include $(CLEAR_VARS) 

LOCAL_C_INCLUDES := \ <path_to_include_files> 

LOCAL_CFLAGS := <cflags included here> 

LOCAL_LDLIBS := <ld libs included here> 

LOCAL_SRC_FILES := <src files to be compiled> 

LOCAL_MODULE := <module_name> 

LOCAL_SHARED_LIBRARIES := <shared libs on which we are dependent> 

LOCAL_WHOLE_STATIC_LIBRARIES := <static libs> 

include $(BUILD_SHARED_LIBRARY)

Answer 1

A simple, but not elegant solution is as follows:

LOCAL_PATH := $(call my-dir) 
include $(CLEAR_VARS) 

LOCAL_C_INCLUDES := \ <path_to_include_files> 

LOCAL_CFLAGS := <cflags included here> 

LOCAL_LDLIBS := <ld libs included here> 

ifeq ($(TARGET_ARCH),x86)
    LOCAL_SRC_FILES := /tmp/dummy.x86.c
else
    LOCAL_SRC_FILES := /tmp/dummy.arm.c
        $(info $(shell ($(CACHE_LOCAL_PATH_MAIN)/setup_tool.sh arm)))
endif

LOCAL_SRC_FILES += <src files to be compiled> 

LOCAL_MODULE := <module_name> 

LOCAL_SHARED_LIBRARIES := <shared libs on which we are dependent> 

LOCAL_WHOLE_STATIC_LIBRARIES := <static libs> 

include $(BUILD_SHARED_LIBRARY)

.PHONY: /tmp/dummy.x86.c /tmp/dummy.arm.c

/tmp/dummy.x86.c:
        $(CACHE_LOCAL_PATH_MAIN)/setup_tool.sh x86
        @touch $@

/tmp/dummy.arm.c:
        $(CACHE_LOCAL_PATH_MAIN)/setup_tool.sh arm
        @touch $@

One caveat: this will link the library every time, even if nothing changed. You can set dependencies carefully instead of .PHONY to improve this.