1 # SPDX-License-Identifier: GPL-2.0-only
4 # Usage: CROSS_COMPILE := $(call cc-cross-prefix, m68k-linux-gnu- m68k-linux-)
5 # Return first <prefix> where a <prefix>gcc is found in PATH.
6 # If no gcc found in PATH with listed prefixes return nothing
8 # Note: '2>/dev/null' is here to force Make to invoke a shell. Otherwise, it
9 # would try to directly execute the shell builtin 'command'. This workaround
10 # should be kept for a long time since this issue was fixed only after the
11 # GNU Make 4.2.1 release.
12 cc-cross-prefix = $(firstword $(foreach c, $(1), \
13 $(if $(shell command -v -- $(c)gcc 2>/dev/null), $(c))))
15 # output directory for tests below
16 TMPOUT = $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/).tmp_$$$$
19 # Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise)
20 # Exit code chooses option. "$$TMP" serves as a temporary file and is
21 # automatically cleaned up.
22 try-run = $(shell set -e; \
24 trap "rm -rf $(TMPOUT)" EXIT; \
26 if ($(1)) >/dev/null 2>&1; \
32 # Usage: aflags-y += $(call as-option,-Wa$(comma)-isa=foo,)
34 as-option = $(call try-run,\
35 $(CC) -Werror $(KBUILD_AFLAGS) $(1) -c -x assembler-with-cpp /dev/null -o "$$TMP",$(1),$(2))
38 # Usage: aflags-y += $(call as-instr,instr,option1,option2)
40 as-instr = $(call try-run,\
41 printf "%b\n" "$(1)" | $(CC) -Werror $(KBUILD_AFLAGS) -c -x assembler-with-cpp -o "$$TMP" -,$(2),$(3))
44 # Usage: MY_CFLAGS += $(call __cc-option,$(CC),$(MY_CFLAGS),-march=winchip-c6,-march=i586)
45 __cc-option = $(call try-run,\
46 $(1) -Werror $(2) $(3) -c -x c /dev/null -o "$$TMP",$(3),$(4))
49 # Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
51 cc-option = $(call __cc-option, $(CC),\
52 $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS),$(1),$(2))
55 # Usage: flag := $(call cc-option-yn,-march=winchip-c6)
56 cc-option-yn = $(call try-run,\
57 $(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
60 # Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable)
61 cc-disable-warning = $(call try-run,\
62 $(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
65 # Usage: cflags-$(call gcc-min-version, 70100) += -foo
66 gcc-min-version = $(shell [ $(CONFIG_GCC_VERSION)0 -ge $(1)0 ] && echo y)
69 # Usage: cflags-$(call clang-min-version, 110000) += -foo
70 clang-min-version = $(shell [ $(CONFIG_CLANG_VERSION)0 -ge $(1)0 ] && echo y)
73 # Usage: KBUILD_LDFLAGS += $(call ld-option, -X, -Y)
74 ld-option = $(call try-run, $(LD) $(KBUILD_LDFLAGS) $(1) -v,$(1),$(2),$(3))
77 # Usage: $(call ld-ifversion, -ge, 22252, y)
78 ld-ifversion = $(shell [ $(CONFIG_LD_VERSION)0 $(1) $(2)0 ] && echo $(3) || echo $(4))