Error in cyttsp4 (linux kernel) Makefile - c++

Question

The below is the Makefile for cyttsp4 inside the Linux kernel that I'm compiling for Android, using the kyasu msm8974 project (https://github.com/kyasu/android_kernel_samsung_msm8974).
### CYTTSP
#obj-m += cyttsp4.o
obj-$(CONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4) += cyttsp4_core.o
obj-$(CONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4) += cyttsp4_i2c.o
obj-$(CONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4) += cyttsp4_platform.o
obj-$(CONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4) += cyttsp4_devtree.o
obj-$(CONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4) += cyttsp4_mt_common.o
obj-$(CONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4) += cyttsp4_mtb.o
obj-$(CONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4) += cyttsp4_btn.o
obj-$(CONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4) += cyttsp4_debug.o
obj-$(CONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4) += cyttsp4_device_access.o
obj-$(CONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4) += cyttsp4_loader.o
obj-$(CONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4) += cyttsp4_samsung_sysfs.o
CY_CFLAG_ADD =\
-DCONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4\
-DCONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4_DEVICETREE_SUPPORT\
-DCONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4_BUTTON\
-DCONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4_DEVICE_ACCESS\
-DCONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4_LOADER\
-DCONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4_PLATFORM_FW_UPGRADE\
-DCONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4_BINARY_FW_UPGRADE
CY_CFLAG_REMOVE =\
-DCYTTSP4_PDATA_IN_PLATFORM_C\
-DCONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4_PROXIMITY\
-DCONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4_PLATFORM_TTCONFIG_UPGRADE\
-DCONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4_DEVICE_ACCESS_API\
-DCONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4_DEBUG\
-DCONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4_MANUAL_TTCONFIG_UPGRADE
CFLAGS_cyttsp4_core.o += $(CY_CFLAG_ADD) -DDEBUG
CFLAGS_cyttsp4_i2c.o += $(CY_CFLAG_ADD) -DDEBUG
CFLAGS_cyttsp4_spi.o += $(CY_CFLAG_ADD)
CFLAGS_cyttsp4_mta.o += $(CY_CFLAG_ADD)
CFLAGS_cyttsp4_mtb.o += $(CY_CFLAG_ADD)
CFLAGS_cyttsp4_mt_a.o += $(CY_CFLAG_ADD)
CFLAGS_cyttsp4_mt_b.o += $(CY_CFLAG_ADD)
CFLAGS_cyttsp4_mt_common.o += $(CY_CFLAG_ADD)
CFLAGS_cyttsp4_btn.o += $(CY_CFLAG_ADD)
CFLAGS_cyttsp4_proximity.o += $(CY_CFLAG_ADD)
CFLAGS_cyttsp4_samsung_sysfs.o += $(CY_CFLAG_ADD)
CFLAGS_cyttsp4_device_access.o += $(CY_CFLAG_ADD)
CFLAGS_cyttsp4_test_device_access_api.o += $(CY_CFLAG_ADD)
CFLAGS_cyttsp4_loader.o += $(CY_CFLAG_ADD)
CFLAGS_cyttsp4_debug.o += $(CY_CFLAG_ADD)
CFLAGS_cyttsp4_devtree.o += $(CY_CFLAG_ADD) -DDEBUG
CFLAGS_cyttsp4_platform.o += $(CY_CFLAG_ADD) -DDEBUG
CFLAGS_cyttsp4_core.o -= $(CY_CFLAG_REMOVE)
CFLAGS_cyttsp4_i2c.o -= $(CY_CFLAG_REMOVE)
CFLAGS_cyttsp4_spi.o -= $(CY_CFLAG_REMOVE)
CFLAGS_cyttsp4_mta.o -= $(CY_CFLAG_REMOVE)
CFLAGS_cyttsp4_mtb.o -= $(CY_CFLAG_REMOVE)
CFLAGS_cyttsp4_mt_a.o -= $(CY_CFLAG_REMOVE)
CFLAGS_cyttsp4_mt_b.o -= $(CY_CFLAG_REMOVE)
CFLAGS_cyttsp4_mt_common.o -= $(CY_CFLAG_REMOVE)
CFLAGS_cyttsp4_btn.o -= $(CY_CFLAG_REMOVE)
CFLAGS_cyttsp4_proximity.o -= $(CY_CFLAG_REMOVE)
CFLAGS_cyttsp4_samsung_sysfs.o -= $(CY_CFLAG_REMOVE)
CFLAGS_cyttsp4_device_access.o -= $(CY_CFLAG_REMOVE)
CFLAGS_cyttsp4_test_device_access_api.o -= $(CY_CFLAG_REMOVE)
CFLAGS_cyttsp4_loader.o -= $(CY_CFLAG_REMOVE)
CFLAGS_cyttsp4_debug.o -= $(CY_CFLAG_REMOVE)
CFLAGS_cyttsp4_devtree.o -= $(CY_CFLAG_REMOVE)
CFLAGS_cyttsp4_platform.o -= $(CY_CFLAG_REMOVE)
The error I'm getting is:
/home/USER/Projects/OS/android_kernel_samsung_msm8974/drivers/gpu/gpu_sysfs/Kbuild:29: **** Make sure target file is defined. Check the TARGET and GPU configs in Makefile and Kernel Config. Module won't work without target file. ****
/home/USER/Projects/OS/android_kernel_samsung_msm8974/drivers/input/touchscreen/cyttsp4/Makefile:50: *** missing separator. Stop.
scripts/Makefile.clean:94: recipe for target 'drivers/input/touchscreen/cyttsp4' failed
make[3]: *** [drivers/input/touchscreen/cyttsp4] Error 2
scripts/Makefile.clean:94: recipe for target 'drivers/input/touchscreen' failed
make[2]: *** [drivers/input/touchscreen] Error 2
scripts/Makefile.clean:94: recipe for target 'drivers/input' failed
make[1]: *** [drivers/input] Error 2
Makefile:1201: recipe for target '_clean_drivers' failed
make: *** [_clean_drivers] Error 2

Answer 1

This is (partially) written using my S4 i9506 as a keyboard, if you want Nethunter on your S4 comment your interest and ill get started on a guide to port it yourself. I'll make one soon anyway but if people are interested I'll put more effort into making a guide to porting Nethunter faster.
Basically, as mentioned by #Tsyvarev, there's no -= command in Makefiles. Basically, whoever made the Makefile for Cyttsp4 (at least in the kernel sources I had) didn't do a very good job and after some research they probably thought just like me that the separator missing error was due to a missing tab somewhere which everyone suggests when you search for this issue. A quick search with #Tsyvarev's info about -= not existing I found the proper way to do what they want. Here's the complete Makefile with the proper alteration. You use $(filter-out, VARS_TO_REMOVE, RESULT) to remove flags.
The error is so stupid I don't see how it was made in the first place, considering it was found inside the source code of a kernel, and the people that make kernels are generally not this unskilled, or else they wouldn't be making kernels.
Wait a minute... I'm making errors and I'm... Oh...
Anyway, here's the code!
### CYTTSP
#obj-m += cyttsp4.o
obj-$(CONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4) += cyttsp4_core.o
obj-$(CONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4) += cyttsp4_i2c.o
obj-$(CONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4) += cyttsp4_platform.o
obj-$(CONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4) += cyttsp4_devtree.o
obj-$(CONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4) += cyttsp4_mt_common.o
obj-$(CONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4) += cyttsp4_mtb.o
obj-$(CONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4) += cyttsp4_btn.o
obj-$(CONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4) += cyttsp4_debug.o
obj-$(CONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4) += cyttsp4_device_access.o
obj-$(CONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4) += cyttsp4_loader.o
obj-$(CONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4) += cyttsp4_samsung_sysfs.o
CY_CFLAG_ADD =\
-DCONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4\
-DCONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4_DEVICETREE_SUPPORT\
-DCONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4_BUTTON\
-DCONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4_DEVICE_ACCESS\
-DCONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4_LOADER\
-DCONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4_PLATFORM_FW_UPGRADE\
-DCONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4_BINARY_FW_UPGRADE
CY_CFLAG_REMOVE =\
-DCYTTSP4_PDATA_IN_PLATFORM_C\
-DCONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4_PROXIMITY\
-DCONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4_PLATFORM_TTCONFIG_UPGRADE\
-DCONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4_DEVICE_ACCESS_API\
-DCONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4_DEBUG\
-DCONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4_MANUAL_TTCONFIG_UPGRADE
CFLAGS_cyttsp4_core.o += $(CY_CFLAG_ADD) -DDEBUG
CFLAGS_cyttsp4_i2c.o += $(CY_CFLAG_ADD) -DDEBUG
CFLAGS_cyttsp4_spi.o += $(CY_CFLAG_ADD)
CFLAGS_cyttsp4_mta.o += $(CY_CFLAG_ADD)
CFLAGS_cyttsp4_mtb.o += $(CY_CFLAG_ADD)
CFLAGS_cyttsp4_mt_a.o += $(CY_CFLAG_ADD)
CFLAGS_cyttsp4_mt_b.o += $(CY_CFLAG_ADD)
CFLAGS_cyttsp4_mt_common.o += $(CY_CFLAG_ADD)
CFLAGS_cyttsp4_btn.o += $(CY_CFLAG_ADD)
CFLAGS_cyttsp4_proximity.o += $(CY_CFLAG_ADD)
CFLAGS_cyttsp4_samsung_sysfs.o += $(CY_CFLAG_ADD)
CFLAGS_cyttsp4_device_access.o += $(CY_CFLAG_ADD)
CFLAGS_cyttsp4_test_device_access_api.o += $(CY_CFLAG_ADD)
CFLAGS_cyttsp4_loader.o += $(CY_CFLAG_ADD)
CFLAGS_cyttsp4_debug.o += $(CY_CFLAG_ADD)
CFLAGS_cyttsp4_devtree.o += $(CY_CFLAG_ADD) -DDEBUG
CFLAGS_cyttsp4_platform.o += $(CY_CFLAG_ADD) -DDEBUG
CFLAGS_cyttsp4_core.o := $(filter-out $(CY_CFLAG_REMOVE),$(CFLAGS_cyttsp4_core.o))
CFLAGS_cyttsp4_i2c.o := $(filter-out $(CY_CFLAG_REMOVE),$(CFLAGS_cyttsp4_i2c.o))
CFLAGS_cyttsp4_spi.o := $(filter-out $(CY_CFLAG_REMOVE),$(CFLAGS_cyttsp4_spi.o))
CFLAGS_cyttsp4_mta.o := $(filter-out $(CY_CFLAG_REMOVE),$(CFLAGS_cyttsp4_mta.o))
CFLAGS_cyttsp4_mtb.o := $(filter-out $(CY_CFLAG_REMOVE),$(CFLAGS_cyttsp4_mtb.o))
CFLAGS_cyttsp4_mt_a.o := $(filter-out $(CY_CFLAG_REMOVE),$(CFLAGS_cyttsp4_mt_a.o))
CFLAGS_cyttsp4_mt_b.o := $(filter-out $(CY_CFLAG_REMOVE),$(CFLAGS_cyttsp4_mt_b.o))
CFLAGS_cyttsp4_mt_common.o := $(filter-out $(CY_CFLAG_REMOVE),$(CFLAGS_cyttsp4_mt_common.o))
CFLAGS_cyttsp4_btn.o := $(filter-out $(CY_CFLAG_REMOVE),$(CFLAGS_cyttsp4_btn.o))
CFLAGS_cyttsp4_proximity.o := $(filter-out $(CY_CFLAG_REMOVE),$(CFLAGS_cyttsp4_proximity.o))
CFLAGS_cyttsp4_samsung_sysfs.o := $(filter-out $(CY_CFLAG_REMOVE),$(CFLAGS_cyttsp4_samsung_sysfs.o))
CFLAGS_cyttsp4_device_access.o := $(filter-out $(CY_CFLAG_REMOVE),$(CFLAGS_cyttsp4_device_access.o))
CFLAGS_cyttsp4_test_device_access_api.o := $(filter-out $(CY_CFLAG_REMOVE),$(CFLAGS_cyttsp4_test_device_access_api.o))
CFLAGS_cyttsp4_loader.o := $(filter-out $(CY_CFLAG_REMOVE),$(CFLAGS_cyttsp4_loader.o))
CFLAGS_cyttsp4_debug.o := $(filter-out $(CY_CFLAG_REMOVE),$(CFLAGS_cyttsp4_debug.o))
CFLAGS_cyttsp4_devtree.o := $(filter-out $(CY_CFLAG_REMOVE),$(CFLAGS_cyttsp4_devtree.o))
CFLAGS_cyttsp4_platform.o := $(filter-out $(CY_CFLAG_REMOVE),$(CFLAGS_cyttsp4_platform.o))