kbuild: refactor cc-cross-prefix implementation

- $(word 1, <text>) is equivalent to $(firstword <text>) - hardcode "gcc" instead of $(CC) - minimize the shell script part A little more notes in case $(filter-out -%, ...) is not clear. arch/mips/Makefile passes prefixes depending on the configuration. CROSS_COMPILE := $(call cc-cross-prefix, $(tool-archpref)-linux- \ $(tool-archpref)-linux-gnu- $(tool-archpref)-unknown-linux-gnu-) In the Kconfig stage (e.g. when you run 'make defconfig'), neither CONFIG_32BIT nor CONFIG_64BIT is defined. So, $(tool-archpref) is empty. As a result, "-linux -linux-gnu- -unknown-linux-gnu" is passed into cc-cross-prefix. The command 'which' assumes arguments starting with a hyphen as command options, then emits the following messages: Illegal option -l Illegal option -l Illegal option -u I think it is strange to define CROSS_COMPILE depending on the CONFIG options since you need to feed $(CC) to Kconfig, but it is how MIPS Makefile currently works. Anyway, it would not hurt to filter-out invalid strings beforehand.

Masahiro Yamada committed 7 years ago

Commit bd55f961 parent 88110711 file · +4 −8Browse files

Showing the changes to scripts (1 of 1 file). Show all

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scripts/Kbuild.include+4−8

@@ -71,14 +71,10 @@ endef · 70 unmodified lines
71	71
72	72	# cc-cross-prefix
73	73	# Usage: CROSS_COMPILE := $(call cc-cross-prefix, m68k-linux-gnu- m68k-linux-)
74		−# Return first prefix where a prefix$(CC) is found in PATH.
75		−# If no $(CC) found in PATH with listed prefixes return nothing
76		−cc-cross-prefix = \
77		− $(word 1, $(foreach c,$(1), \
78		− $(shell set -e; \
79		− if (which $(strip $(c))$(CC)) > /dev/null 2>&1 ; then \
80		− echo $(c); \
81		− fi)))
	74	+# Return first <prefix> where a <prefix>gcc is found in PATH.
	75	+# If no gcc found in PATH with listed prefixes return nothing
	76	+cc-cross-prefix = $(firstword $(foreach c, $(filter-out -%, $(1)), \
	77	+ $(if $(shell which $(c)gcc), $(c))))
82	78
83	79	# output directory for tests below
84	80	TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/)