Commit d3a918c6 authored by Masahiro Yamada's avatar Masahiro Yamada
Browse files

kbuild: remove cc-version macro 



There is no more direct user of this macro; it is only used by
cc-ifversion.

Calling this macro is not efficient since it invokes the compiler to
get the compiler version. CONFIG_GCC_VERSION is already calculated in
the Kconfig stage, so Makefile can reuse it.

Here is a note about the slight difference between cc-version and
CONFIG_GCC_VERSION:

When using Clang, cc-version is evaluated to '0402' because Clang
defines __GNUC__ and __GNUC__MINOR__, and looks like GCC 4.2 in the
version point of view. On the other hand, CONFIG_GCC_VERSION=0
when $(CC) is clang.

There are currently two users of cc-ifversion:
  arch/mips/loongson64/Platform
  arch/powerpc/Makefile

They are not affected by this change.

The format of cc-version is <major><minor>, while CONFIG_GCC_VERSION
<major><minor><patch>. I adjusted cc-ifversion for the difference of
the number of digits.

Signed-off-by: default avatarMasahiro Yamada <yamada.masahiro@socionext.com>
parent 00250b52

Documentation/kbuild/makefiles.txt

+0 −17
Original line number Diff line number Diff line
@@ -499,23 +499,6 @@ more details, with real examples. 
	In the above example, -Wno-unused-but-set-variable will be added to

	KBUILD_CFLAGS only if gcc really accepts it.



    cc-version

	cc-version returns a numerical version of the $(CC) compiler version.

	The format is <major><minor> where both are two digits. So for example

	gcc 3.41 would return 0341.

	cc-version is useful when a specific $(CC) version is faulty in one

	area, for example -mregparm=3 was broken in some gcc versions

	even though the option was accepted by gcc.



	Example:

		#arch/x86/Makefile

		cflags-y += $(shell \

		if [ $(cc-version) -ge 0300 ] ; then \

			echo "-mregparm=3"; fi ;)



	In the above example, -mregparm=3 is only used for gcc version greater

	than or equal to gcc 3.0.



    cc-ifversion

	cc-ifversion tests the version of $(CC) and equals the fourth parameter

	if version expression is true, or the fifth (if given) if the version

scripts/Kbuild.include

+1 −4
Original line number Diff line number Diff line
@@ -134,12 +134,9 @@ cc-option-yn = $(call try-run,\ 
cc-disable-warning = $(call try-run,\

	$(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))



# cc-version

cc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC))



# cc-ifversion

# Usage:  EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)

cc-ifversion = $(shell [ $(cc-version) $(1) $(2) ] && echo $(3) || echo $(4))

cc-ifversion = $(shell [ $(CONFIG_GCC_VERSION)0 $(1) $(2)000 ] && echo $(3) || echo $(4))



# cc-ldoption

# Usage: ldflags += $(call cc-ldoption, -Wl$(comma)--hash-style=both)

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