# SPDX-License-Identifier: GPL-2.0-only # cc-cross-prefix# Usage: CROSS_COMPILE := $(call cc-cross-prefix, m68k-linux-gnu- m68k-linux-)# Return first <prefix> where a <prefix>gcc is found in PATH.# If no gcc found in PATH with listed prefixes return nothing## Note: '2>/dev/null' is here to force Make to invoke a shell. Otherwise, it# would try to directly execute the shell builtin 'command'. This workaround# should be kept for a long time since this issue was fixed only after the# GNU Make 4.2.1 release.cc-cross-prefix = $(firstword $(foreach c, $(1), \			$(if $(shell command -v -- $(c)gcc 2>/dev/null), $(c)))) # output directory for tests belowTMPOUT = $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/).tmp_$$$$ # try-run# Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise)# Exit code chooses option. "$$TMP" serves as a temporary file and is# automatically cleaned up.try-run = $(shell set -e;		\	TMP=$(TMPOUT)/tmp;		\	trap "rm -rf $(TMPOUT)" EXIT;	\	mkdir -p $(TMPOUT);		\	if ($(1)) >/dev/null 2>&1;	\	then echo "$(2)";		\	else echo "$(3)";		\	fi) # as-option# Usage: aflags-y += $(call as-option,-Wa$(comma)-isa=foo,) as-option = $(call try-run,\	$(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS) $(1) -c -x assembler-with-cpp /dev/null -o "$$TMP",$(1),$(2)) # as-instr# Usage: aflags-y += $(call as-instr,instr,option1,option2) as-instr = $(call try-run,\	printf "%b\n" "$(1)" | $(CC) -Werror $(CLANG_FLAGS) $(KBUILD_AFLAGS) -Wa$(comma)--fatal-warnings -c -x assembler-with-cpp -o "$$TMP" -,$(2),$(3)) # __cc-option# Usage: MY_CFLAGS += $(call __cc-option,$(CC),$(MY_CFLAGS),-march=winchip-c6,-march=i586)__cc-option = $(call try-run,\	$(1) -Werror $(2) $(3) -c -x c /dev/null -o "$$TMP",$(3),$(4)) # cc-option# Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586) cc-option = $(call __cc-option, $(CC),\	$(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS),$(1),$(2)) # cc-option-yn# Usage: flag := $(call cc-option-yn,-march=winchip-c6)cc-option-yn = $(if $(call cc-option,$1),y,n) # cc-disable-warning# Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable)cc-disable-warning = $(if $(call cc-option,-W$(strip $1)),-Wno-$(strip $1)) # gcc-min-version# Usage: cflags-$(call gcc-min-version, 70100) += -foogcc-min-version = $(call test-ge, $(CONFIG_GCC_VERSION), $1) # clang-min-version# Usage: cflags-$(call clang-min-version, 110000) += -fooclang-min-version = $(call test-ge, $(CONFIG_CLANG_VERSION), $1) # ld-option# Usage: KBUILD_LDFLAGS += $(call ld-option, -X, -Y)ld-option = $(call try-run, $(LD) $(KBUILD_LDFLAGS) $(1) -v,$(1),$(2),$(3)) # __rustc-option# Usage: MY_RUSTFLAGS += $(call __rustc-option,$(RUSTC),$(MY_RUSTFLAGS),-Cinstrument-coverage,-Zinstrument-coverage)# TODO: remove RUSTC_BOOTSTRAP=1 when we raise the minimum GNU Make version to 4.4__rustc-option = $(call try-run,\	echo '#![allow(missing_docs)]#![feature(no_core)]#![no_core]' | RUSTC_BOOTSTRAP=1\	$(1) --sysroot=/dev/null $(filter-out --sysroot=/dev/null,$(2)) $(3)\	--crate-type=rlib --out-dir=$(TMPOUT) --emit=obj=- - >/dev/null,$(3),$(4)) # rustc-option# Usage: rustflags-y += $(call rustc-option,-Cinstrument-coverage,-Zinstrument-coverage)rustc-option = $(call __rustc-option, $(RUSTC),\	$(KBUILD_RUSTFLAGS),$(1),$(2)) # rustc-option-yn# Usage: flag := $(call rustc-option-yn,-Cinstrument-coverage)rustc-option-yn = $(if $(call rustc-option,$1),y,n)