linux-stable/scripts/Kconfig.include
Masahiro Yamada 10269fd37f kconfig: shorten the temporary directory name for cc-option
The cc-option macro creates the temporary directory, .tmp_$$$$.
Shell expands '$$' into its process ID. '$$$$' results in repeated PID.

In Makefile, '$$$$' is correct (see TMPOUT in scripts/Malefile.compiler)
because '$$' is an escape sequence of '$'. Make expands '$$$$' into '$$',
then shell expands it into the process ID.

This does not apply to Kconfig because Kconfig requires variable
references to be enclosed by curly braces, like ${variable}.
The '$' that is not followed by '{' loses its effect.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nicolas Schier <nicolas@fjasle.eu>
2022-07-27 21:18:00 +09:00

65 lines
2.6 KiB
Text

# SPDX-License-Identifier: GPL-2.0-only
# Kconfig helper macros
# Convenient variables
comma := ,
quote := "
squote := '
empty :=
space := $(empty) $(empty)
dollar := $
right_paren := )
left_paren := (
# $(if-success,<command>,<then>,<else>)
# Return <then> if <command> exits with 0, <else> otherwise.
if-success = $(shell,{ $(1); } >/dev/null 2>&1 && echo "$(2)" || echo "$(3)")
# $(success,<command>)
# Return y if <command> exits with 0, n otherwise
success = $(if-success,$(1),y,n)
# $(failure,<command>)
# Return n if <command> exits with 0, y otherwise
failure = $(if-success,$(1),n,y)
# $(cc-option,<flag>)
# Return y if the compiler supports <flag>, n otherwise
cc-option = $(success,mkdir .tmp_$$; trap "rm -rf .tmp_$$" EXIT; $(CC) -Werror $(CLANG_FLAGS) $(1) -c -x c /dev/null -o .tmp_$$/tmp.o)
# $(ld-option,<flag>)
# Return y if the linker supports <flag>, n otherwise
ld-option = $(success,$(LD) -v $(1))
# $(as-instr,<instr>)
# Return y if the assembler supports <instr>, n otherwise
as-instr = $(success,printf "%b\n" "$(1)" | $(CC) $(CLANG_FLAGS) -c -x assembler -o /dev/null -)
# check if $(CC) and $(LD) exist
$(error-if,$(failure,command -v $(CC)),compiler '$(CC)' not found)
$(error-if,$(failure,command -v $(LD)),linker '$(LD)' not found)
# Get the compiler name, version, and error out if it is not supported.
cc-info := $(shell,$(srctree)/scripts/cc-version.sh $(CC))
$(error-if,$(success,test -z "$(cc-info)"),Sorry$(comma) this compiler is not supported.)
cc-name := $(shell,set -- $(cc-info) && echo $1)
cc-version := $(shell,set -- $(cc-info) && echo $2)
# Get the assembler name, version, and error out if it is not supported.
as-info := $(shell,$(srctree)/scripts/as-version.sh $(CC) $(CLANG_FLAGS))
$(error-if,$(success,test -z "$(as-info)"),Sorry$(comma) this assembler is not supported.)
as-name := $(shell,set -- $(as-info) && echo $1)
as-version := $(shell,set -- $(as-info) && echo $2)
# Get the linker name, version, and error out if it is not supported.
ld-info := $(shell,$(srctree)/scripts/ld-version.sh $(LD))
$(error-if,$(success,test -z "$(ld-info)"),Sorry$(comma) this linker is not supported.)
ld-name := $(shell,set -- $(ld-info) && echo $1)
ld-version := $(shell,set -- $(ld-info) && echo $2)
# machine bit flags
# $(m32-flag): -m32 if the compiler supports it, or an empty string otherwise.
# $(m64-flag): -m64 if the compiler supports it, or an empty string otherwise.
cc-option-bit = $(if-success,$(CC) -Werror $(1) -E -x c /dev/null -o /dev/null,$(1))
m32-flag := $(cc-option-bit,-m32)
m64-flag := $(cc-option-bit,-m64)