1# SPDX-License-Identifier: GPL-2.0-only 2 3# cc-cross-prefix 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 7# 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. 12cc-cross-prefix = $(firstword $(foreach c, $(1), \ 13 $(if $(shell command -v -- $(c)gcc 2>/dev/null), $(c)))) 14 15# output directory for tests below 16TMPOUT = $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/).tmp_$$$$ 17 18# try-run 19# Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise) 20# Exit code chooses option. "$$TMP" serves as a temporary file and is 21# automatically cleaned up. 22try-run = $(shell set -e; \ 23 TMP=$(TMPOUT)/tmp; \ 24 mkdir -p $(TMPOUT); \ 25 trap "rm -rf $(TMPOUT)" EXIT; \ 26 if ($(1)) >/dev/null 2>&1; \ 27 then echo "$(2)"; \ 28 else echo "$(3)"; \ 29 fi) 30 31# as-option 32# Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,) 33 34as-option = $(call try-run,\ 35 $(CC) $(KBUILD_CFLAGS) $(1) -c -x assembler /dev/null -o "$$TMP",$(1),$(2)) 36 37# as-instr 38# Usage: cflags-y += $(call as-instr,instr,option1,option2) 39 40as-instr = $(call try-run,\ 41 printf "%b\n" "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3)) 42 43# __cc-option 44# Usage: MY_CFLAGS += $(call __cc-option,$(CC),$(MY_CFLAGS),-march=winchip-c6,-march=i586) 45__cc-option = $(call try-run,\ 46 $(1) -Werror $(2) $(3) -c -x c /dev/null -o "$$TMP",$(3),$(4)) 47 48# cc-option 49# Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586) 50 51cc-option = $(call __cc-option, $(CC),\ 52 $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS),$(1),$(2)) 53 54# cc-option-yn 55# Usage: flag := $(call cc-option-yn,-march=winchip-c6) 56cc-option-yn = $(call try-run,\ 57 $(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n) 58 59# cc-disable-warning 60# Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable) 61cc-disable-warning = $(call try-run,\ 62 $(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1))) 63 64# cc-ifversion 65# Usage: EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1) 66cc-ifversion = $(shell [ $(CONFIG_GCC_VERSION)0 $(1) $(2)000 ] && echo $(3) || echo $(4)) 67 68# ld-option 69# Usage: KBUILD_LDFLAGS += $(call ld-option, -X, -Y) 70ld-option = $(call try-run, $(LD) $(KBUILD_LDFLAGS) $(1) -v,$(1),$(2),$(3)) 71 72# ld-ifversion 73# Usage: $(call ld-ifversion, -ge, 22252, y) 74ld-ifversion = $(shell [ $(CONFIG_LD_VERSION)0 $(1) $(2)0 ] && echo $(3) || echo $(4)) 75