Makefile: Allow forcing ccache only if KERNEL_USE_CCACHE is defined

In order to use ccache, export KERNEL_USE_CCACHE=1

Signed-off-by: Shashank Baghel <[email protected]>

Makefile

@@ -221,7 +221,9 @@ VPATH		:= $(srctree)$(if $(KBUILD_EXTMOD),:$(KBUILD_EXTMOD))
 
 export srctree objtree VPATH
 
+ifdef KERNEL_USE_CCACHE
 CCACHE := $(shell which ccache)
+endif
 
 # SUBARCH tells the usermode build what the underlying arch is.  That is set
 # first, and if a usermode build is happening, the "ARCH=um" on the command
@@ -303,8 +305,13 @@ CONFIG_SHELL := $(shell if [ -x "$$BASH" ]; then echo $$BASH; \
 	  else if [ -x /bin/bash ]; then echo /bin/bash; \
 	  else echo sh; fi ; fi)
 
+ifdef KERNEL_USE_CCACHE
 HOSTCC       = $(CCACHE) gcc
 HOSTCXX      = $(CCACHE) g++
+else
+HOSTCC       = gcc
+HOSTCXX      = g++
+endif
 HOSTCFLAGS   := -Wall -Wmissing-prototypes -Wstrict-prototypes -O2 -fomit-frame-pointer -std=gnu89
 HOSTCXXFLAGS = -O2
 
@@ -341,7 +348,11 @@ include scripts/Kbuild.include
 # Make variables (CC, etc...)
 AS		= $(CROSS_COMPILE)as
 LD		= $(CROSS_COMPILE)ld
+ifdef KERNEL_USE_CCACHE
 CC		= $(CCACHE) $(CROSS_COMPILE)gcc
+else
+CC		= $(CROSS_COMPILE)gcc
+endif
 CPP		= $(CC) -E
 AR		= $(CROSS_COMPILE)ar
 NM		= $(CROSS_COMPILE)nm