[U-Boot] [PATCH v8 08/38] Makefile: move some variable definitions to the top Makefile

[Masahiro Yamada <yamada.m@jp.panasonic.com>]

This commit moves some variable definitions from config.mk
to the top Makefile:

  - HOSTCC, HOSTCFLAGS, HOSTLDFLAGS
  - AS, LD, CC, CPP, etc.
  - SHELL (renamed to CONFIG_SHELL)

I'd like to slim down config.mk file
because it is included from all recursive make.
It is redundant to re-define the variables
every time descending into sub directories.
We should rather define them at the top Makefile
and export them.

U-Boot makefiles has been used "SHELL" variable to store shell
chosen for the user, whereas Linux Kernel uses "CONFIG_SHELL".

We should never use "SHELL" variable because it is
a special variable for GNU Make.
Changing SHELL may cause unpredictable side effects
whose root cause is usually difficult to find.
We should use a generic variable name "CONFIG_SHELL".

We should not use the syntax as follows either:

    rm -f $(obj)tools/env/{fw_printenv,fw_setenv}

This depends on "bash" although GNU Make generally
invokes "sh" to run the each rule.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
---

O'REILLY GNU Make says like follows about SHELL variable:

By default, /bin/sh is used for the shell.
This shell is controlled by the make variable SHELL
but it is not inherited from the environment.
When make starts, it imports all the variables
from the user?s environment as make variables, except SHELL.
This is because the user?s choice of shell should not cause a
makefile (possibly included in some downloaded software package) to fail.
If a user really wants to change the default shell used by make,
he can set the SHELL variable explicitly in the makefile.

Please refer to the first page of the following PDF file:
http://oreilly.com/catalog/make3/book/ch05.pdf


Changes in v8: None
Changes in v7: None
Changes in v6: None
Changes in v5: None
Changes in v4: None
Changes in v3: None
Changes in v2:
  - Do not use bash-dependent clean rules:
     For example,
         rm -f $(obj)tools/env/{fw_printenv,fw_setenv}
       should be converted to
         rm -f $(addprefix $(obj)tools/env/, fw_printenv fw_setenv)
  - Add more comments in commit log
  - Rebase on v2014.01-rc2 tag

 Makefile  | 94 ++++++++++++++++++++++++++++++++++++++++++++++++++++++---------
 config.mk | 78 ++--------------------------------------------------
 2 files changed, 84 insertions(+), 88 deletions(-)

diff --git a/Makefile b/Makefile
index 5204ab4..0c1eef3 100644
--- a/Makefile
+++ b/Makefile
@@ -161,6 +161,73 @@ ifeq ($(HOSTARCH),$(ARCH))
 CROSS_COMPILE ?=
 endif
 
+# SHELL used by kbuild
+CONFIG_SHELL := $(shell if [ -x "$$BASH" ]; then echo $$BASH; \
+	  else if [ -x /bin/bash ]; then echo /bin/bash; \
+	  else echo sh; fi ; fi)
+
+HOSTCC       = gcc
+HOSTCFLAGS   = -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer
+
+ifeq ($(HOSTOS),cygwin)
+HOSTCFLAGS	+= -ansi
+endif
+
+# Mac OS X / Darwin's C preprocessor is Apple specific.  It
+# generates numerous errors and warnings.  We want to bypass it
+# and use GNU C's cpp.	To do this we pass the -traditional-cpp
+# option to the compiler.  Note that the -traditional-cpp flag
+# DOES NOT have the same semantics as GNU C's flag, all it does
+# is invoke the GNU preprocessor in stock ANSI/ISO C fashion.
+#
+# Apple's linker is similar, thanks to the new 2 stage linking
+# multiple symbol definitions are treated as errors, hence the
+# -multiply_defined suppress option to turn off this error.
+#
+ifeq ($(HOSTOS),darwin)
+# get major and minor product version (e.g. '10' and '6' for Snow Leopard)
+DARWIN_MAJOR_VERSION	= $(shell sw_vers -productVersion | cut -f 1 -d '.')
+DARWIN_MINOR_VERSION	= $(shell sw_vers -productVersion | cut -f 2 -d '.')
+
+os_x_before	= $(shell if [ $(DARWIN_MAJOR_VERSION) -le $(1) -a \
+	$(DARWIN_MINOR_VERSION) -le $(2) ] ; then echo "$(3)"; else echo "$(4)"; fi ;)
+
+# Snow Leopards build environment has no longer restrictions as described above
+HOSTCC       = $(call os_x_before, 10, 5, "cc", "gcc")
+HOSTCFLAGS  += $(call os_x_before, 10, 4, "-traditional-cpp")
+HOSTLDFLAGS += $(call os_x_before, 10, 5, "-multiply_defined suppress")
+endif
+
+# Make variables (CC, etc...)
+
+AS		= $(CROSS_COMPILE)as
+# Always use GNU ld
+ifneq ($(shell $(CROSS_COMPILE)ld.bfd -v 2> /dev/null),)
+LD		= $(CROSS_COMPILE)ld.bfd
+else
+LD		= $(CROSS_COMPILE)ld
+endif
+CC		= $(CROSS_COMPILE)gcc
+CPP		= $(CC) -E
+AR		= $(CROSS_COMPILE)ar
+NM		= $(CROSS_COMPILE)nm
+LDR		= $(CROSS_COMPILE)ldr
+STRIP		= $(CROSS_COMPILE)strip
+OBJCOPY		= $(CROSS_COMPILE)objcopy
+OBJDUMP		= $(CROSS_COMPILE)objdump
+AWK		= awk
+RANLIB		= $(CROSS_COMPILE)RANLIB
+DTC		= dtc
+CHECK		= sparse
+
+CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
+		  -Wbitwise -Wno-return-void -D__CHECK_ENDIAN__ $(CF)
+
+export CONFIG_SHELL HOSTCC HOSTCFLAGS HOSTLDFLAGS CROSS_COMPILE AS LD CC
+export CPP AR NM LDR STRIP OBJCOPY OBJDUMP
+export MAKE AWK
+export DTC CHECK CHECKFLAGS
+
 # load other configuration
 include $(TOPDIR)/config.mk
 
@@ -788,27 +855,28 @@ clean:
 	       $(obj)examples/standalone/interrupt			  \
 	       $(obj)examples/standalone/mem_to_mem_idma2intr		  \
 	       $(obj)examples/standalone/sched				  \
-	       $(obj)examples/standalone/smc911{11,x}_eeprom		  \
+	       $(addprefix $(obj)examples/standalone/, smc91111_eeprom smc911x_eeprom) \
 	       $(obj)examples/standalone/test_burst			  \
 	       $(obj)examples/standalone/timer
-	@rm -f $(obj)examples/api/demo{,.bin}
+	@rm -f $(addprefix $(obj)examples/api/, demo demo.bin)
 	@rm -f $(obj)tools/bmp_logo	   $(obj)tools/easylogo/easylogo  \
 	       $(obj)tools/env/fw_printenv				  \
 	       $(obj)tools/envcrc					  \
-	       $(obj)tools/gdb/{gdbcont,gdbsend}			  \
+	       $(addprefix $(obj)tools/gdb/, gdbcont gdbsend)		  \
 	       $(obj)tools/gen_eth_addr    $(obj)tools/img2srec		  \
-	       $(obj)tools/dump{env,}image		  \
-	       $(obj)tools/mk{env,}image   $(obj)tools/mpc86x_clk	  \
-	       $(obj)tools/mk{$(BOARD),exynos}spl			  \
+	       $(obj)tools/dumpimage					  \
+	       $(addprefix $(obj)tools/, mkenvimage mkimage)		  \
+	       $(obj)tools/mpc86x_clk					  \
+	       $(addprefix $(obj)tools/, mk$(BOARD)spl mkexynosspl)	  \
 	       $(obj)tools/mxsboot					  \
 	       $(obj)tools/ncb		   $(obj)tools/ubsha1		  \
 	       $(obj)tools/kernel-doc/docproc				  \
 	       $(obj)tools/proftool
-	@rm -f $(obj)board/cray/L1/{bootscript.c,bootscript.image}	  \
+	@rm -f $(addprefix $(obj)board/cray/L1/, bootscript.c bootscript.image) \
 	       $(obj)board/matrix_vision/*/bootscript.img		  \
 	       $(obj)spl/board/samsung/$(BOARD)/tools/mk$(BOARD)spl	  \
 	       $(obj)u-boot.lds						  \
-	       $(obj)arch/blackfin/cpu/init.{lds,elf}
+	       $(addprefix $(obj)arch/blackfin/cpu/, init.lds init.elf)
 	@rm -f $(obj)include/bmp_logo.h
 	@rm -f $(obj)include/bmp_logo_data.h
 	@rm -f $(obj)lib/asm-offsets.s
@@ -843,11 +911,11 @@ clobber:	tidy
 	@rm -f $(obj)u-boot.dtb
 	@rm -f $(obj)u-boot.sb
 	@rm -f $(obj)u-boot.spr
-	@rm -f $(obj)nand_spl/{u-boot.{lds,lst},System.map}
-	@rm -f $(obj)nand_spl/{u-boot-nand_spl.lds,u-boot-spl,u-boot-spl.map}
-	@rm -f $(obj)spl/{u-boot-spl,u-boot-spl.bin,u-boot-spl.map}
+	@rm -f $(addprefix $(obj)nand_spl/, u-boot.lds u-boot.lst System.map)
+	@rm -f $(addprefix $(obj)nand_spl/, u-boot-nand_spl.lds u-boot-spl u-boot-spl.map)
+	@rm -f $(addprefix $(obj)spl/, u-boot-spl u-boot-spl.bin u-boot-spl.map)
 	@rm -f $(obj)spl/u-boot-spl.lds
-	@rm -f $(obj)tpl/{u-boot-tpl,u-boot-tpl.bin,u-boot-tpl.map}
+	@rm -f $(addprefix $(obj)tpl/, u-boot-tpl u-boot-tpl.bin u-boot-tpl.map)
 	@rm -f $(obj)tpl/u-boot-spl.lds
 	@rm -f $(obj)MLO MLO.byteswap
 	@rm -f $(obj)SPL
@@ -856,7 +924,7 @@ clobber:	tidy
 	@rm -fr $(obj)include/generated
 	@[ ! -d $(obj)nand_spl ] || find $(obj)nand_spl -name "*" -type l -print | xargs rm -f
 	@rm -f $(obj)dts/*.tmp
-	@rm -f $(obj)spl/u-boot-spl{,-pad}.ais
+	@rm -f $(addprefix $(obj)spl/, u-boot-spl.ais, u-boot-spl-pad.ais)
 
 mrproper \
 distclean:	clobber unconfig
diff --git a/config.mk b/config.mk
index b08be7a..74617d3 100644
--- a/config.mk
+++ b/config.mk
@@ -6,13 +6,6 @@
 #
 #########################################################################
 
-# Set shell to bash if possible, otherwise fall back to sh
-SHELL := $(shell if [ -x "$$BASH" ]; then echo $$BASH; \
-	else if [ -x /bin/bash ]; then echo /bin/bash; \
-	else echo sh; fi; fi)
-
-export	SHELL
-
 ifeq ($(CURDIR),$(SRCTREE))
 dir :=
 else
@@ -55,44 +48,6 @@ PLATFORM_CPPFLAGS =
 PLATFORM_LDFLAGS =
 
 #########################################################################
-
-HOSTCFLAGS	= -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer \
-		  $(HOSTCPPFLAGS)
-
-#
-# Mac OS X / Darwin's C preprocessor is Apple specific.  It
-# generates numerous errors and warnings.  We want to bypass it
-# and use GNU C's cpp.	To do this we pass the -traditional-cpp
-# option to the compiler.  Note that the -traditional-cpp flag
-# DOES NOT have the same semantics as GNU C's flag, all it does
-# is invoke the GNU preprocessor in stock ANSI/ISO C fashion.
-#
-# Apple's linker is similar, thanks to the new 2 stage linking
-# multiple symbol definitions are treated as errors, hence the
-# -multiply_defined suppress option to turn off this error.
-#
-
-ifeq ($(HOSTOS),darwin)
-# get major and minor product version (e.g. '10' and '6' for Snow Leopard)
-DARWIN_MAJOR_VERSION	= $(shell sw_vers -productVersion | cut -f 1 -d '.')
-DARWIN_MINOR_VERSION	= $(shell sw_vers -productVersion | cut -f 2 -d '.')
-
-os_x_before	= $(shell if [ $(DARWIN_MAJOR_VERSION) -le $(1) -a \
-	$(DARWIN_MINOR_VERSION) -le $(2) ] ; then echo "$(3)"; else echo "$(4)"; fi ;)
-
-# Snow Leopards build environment has no longer restrictions as described above
-HOSTCC		 = $(call os_x_before, 10, 5, "cc", "gcc")
-HOSTCFLAGS	+= $(call os_x_before, 10, 4, "-traditional-cpp")
-HOSTLDFLAGS	+= $(call os_x_before, 10, 5, "-multiply_defined suppress")
-else
-HOSTCC		= gcc
-endif
-
-ifeq ($(HOSTOS),cygwin)
-HOSTCFLAGS	+= -ansi
-endif
-
-#########################################################################
 #
 # Option checker, gcc version (courtesy linux kernel) to ensure
 # only supported compiler options are used
@@ -117,30 +72,9 @@ endif
 
 # cc-version
 # Usage gcc-ver := $(call cc-version)
-cc-version = $(shell $(SHELL) $(SRCTREE)/scripts/gcc-version.sh $(CC))
-binutils-version = $(shell $(SHELL) $(SRCTREE)/scripts/binutils-version.sh $(AS))
-dtc-version = $(shell $(SHELL) $(SRCTREE)/scripts/dtc-version.sh $(DTC))
-
-#
-# Include the make variables (CC, etc...)
-#
-AS	= $(CROSS_COMPILE)as
-
-# Always use GNU ld
-LD	= $(shell if $(CROSS_COMPILE)ld.bfd -v > /dev/null 2>&1; \
-		then echo "$(CROSS_COMPILE)ld.bfd"; else echo "$(CROSS_COMPILE)ld"; fi;)
-
-CC	= $(CROSS_COMPILE)gcc
-CPP	= $(CC) -E
-AR	= $(CROSS_COMPILE)ar
-NM	= $(CROSS_COMPILE)nm
-LDR	= $(CROSS_COMPILE)ldr
-STRIP	= $(CROSS_COMPILE)strip
-OBJCOPY = $(CROSS_COMPILE)objcopy
-OBJDUMP = $(CROSS_COMPILE)objdump
-RANLIB	= $(CROSS_COMPILE)RANLIB
-DTC	= dtc
-CHECK	= sparse
+cc-version = $(shell $(CONFIG_SHELL) $(SRCTREE)/scripts/gcc-version.sh $(CC))
+binutils-version = $(shell $(CONFIG_SHELL) $(SRCTREE)/scripts/binutils-version.sh $(AS))
+dtc-version = $(shell $(CONFIG_SHELL) $(SRCTREE)/scripts/dtc-version.sh $(DTC))
 
 #########################################################################
 
@@ -286,10 +220,6 @@ ifneq ($(CONFIG_SPL_TEXT_BASE),)
 LDFLAGS_$(SPL_BIN) += -Ttext $(CONFIG_SPL_TEXT_BASE)
 endif
 
-# Linus' kernel sanity checking tool
-CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
-		  -Wbitwise -Wno-return-void -D__CHECK_ENDIAN__ $(CF)
-
 # Location of a usable BFD library, where we define "usable" as
 # "built for ${HOST}, supports ${TARGET}".  Sensible values are
 # - When cross-compiling: the root of the cross-environment
@@ -315,6 +245,4 @@ endif
 
 #########################################################################
 
-export	HOSTCC HOSTCFLAGS HOSTLDFLAGS CROSS_COMPILE \
-	AS LD CC CPP AR NM STRIP OBJCOPY OBJDUMP MAKE
 export	CONFIG_SYS_TEXT_BASE PLATFORM_CPPFLAGS PLATFORM_RELFLAGS CPPFLAGS CFLAGS AFLAGS
-- 
1.8.3.2