kbuild: raise the minimum GNU Make requirement to 4.0

RHEL/CentOS 7, popular distributions that install GNU Make 3.82, reached EOM/EOL on June 30, 2024. While you may get extended support, it is a good time to raise the minimum GNU Make version. The new requirement, GNU Make 4.0, was released in October, 2013. I did not touch the Makefiles under tools/ because I do not know the requirements for building tools. I do not find any GNU Make version checks under tools/.

Masahiro Yamada committed 2 years ago

Commit 5f996651 parent 712aba53 files · +6 −22Browse files

Unified · Split

3 files

Documentation/process/changes.rst +2 −2
Makefile +3 −19
scripts/Kbuild.include +1 −1

Documentation/process/changes.rst+2−2

@@ -33,7 +33,7 @@ GNU C 5.1 gcc --version · 32 unmodified lines
33	33	Clang/LLVM (optional) 13.0.1 clang --version
34	34	Rust (optional) 1.78.0 rustc --version
35	35	bindgen (optional) 0.65.1 bindgen --version
36		−GNU make 3.82 make --version
	36	+GNU make 4.0 make --version
37	37	bash 4.2 bash --version
38	38	binutils 2.25 ld -v
39	39	flex 2.5.35 flex --version
@@ -111,7 +111,7 @@ It depends on ``libclang``. · 71 unmodified lines
111	111	Make
112	112	----
113	113
114		−You will need GNU make 3.82 or later to build the kernel.
	114	+You will need GNU make 4.0 or later to build the kernel.
115	115
116	116	Bash
117	117	----

Makefile+3−19

@@ -11,8 +11,8 @@ NAME = Baby Opossum Posse · 10 unmodified lines
11	11	# Comments in this file are targeted only to the developer, do not
12	12	# expect to learn how to build the kernel reading this file.
13	13
14		−ifeq ($(filter undefine,$(.FEATURES)),)
15		−$(error GNU Make >= 3.82 is required. Your Make version is $(MAKE_VERSION))
	14	+ifeq ($(filter output-sync,$(.FEATURES)),)
	15	+$(error GNU Make >= 4.0 is required. Your Make version is $(MAKE_VERSION))
16	16	endif
17	17
18	18	$(if $(filter __%, $(MAKECMDGOALS)), \
@@ -93,15 +93,7 @@ endif · 74 unmodified lines
93	93
94	94	# If the user is running make -s (silent mode), suppress echoing of
95	95	# commands
96		−# make-4.0 (and later) keep single letter options in the 1st word of MAKEFLAGS.
97		−
98		−ifeq ($(filter 3.%,$(MAKE_VERSION)),)
99		−short-opts := $(firstword -$(MAKEFLAGS))
100		−else
101		−short-opts := $(filter-out --%,$(MAKEFLAGS))
102		−endif
103		−
104		−ifneq ($(findstring s,$(short-opts)),)
	96	+ifneq ($(findstring s,$(firstword -$(MAKEFLAGS))),)
105	97	quiet=silent_
106	98	override KBUILD_VERBOSE :=
107	99	endif
@@ -201,14 +193,6 @@ ifneq ($(words $(subst :, ,$(abs_srctree))), 1) · 93 unmodified lines
201	193	$(error source directory cannot contain spaces or colons)
202	194	endif
203	195
204		−ifneq ($(filter 3.%,$(MAKE_VERSION)),)
205		−# 'MAKEFLAGS += -rR' does not immediately become effective for GNU Make 3.x
206		−# We need to invoke sub-make to avoid implicit rules in the top Makefile.
207		−need-sub-make := 1
208		−# Cancel implicit rules for this Makefile.
209		−$(this-makefile): ;
210		−endif
211		−
212	196	export sub_make_done := 1
213	197
214	198	endif # sub_make_done

scripts/Kbuild.include+1−1

@@ -68,7 +68,7 @@ kbuild-file = $(or $(wildcard $(src)/Kbuild),$(src)/Makefile) · 67 unmodified lines
68	68	# Read a file, replacing newlines with spaces
69	69	#
70	70	# Make 4.2 or later can read a file by using its builtin function.
71		−ifneq ($(filter-out 3.% 4.0 4.1, $(MAKE_VERSION)),)
	71	+ifneq ($(filter-out 4.0 4.1, $(MAKE_VERSION)),)
72	72	read-file = $(subst $(newline),$(space),$(file < $1))
73	73	else
74	74	read-file = $(shell cat $1 2>/dev/null)