linux/scripts
Masahiro Yamada aec6c60a01 kbuild: check the minimum compiler version in Kconfig
Paul Gortmaker reported a regression in the GCC version check. [1]
If you use GCC 4.8, the build breaks before showing the error message
"error Sorry, your version of GCC is too old - please use 4.9 or newer."

I do not want to apply his fix-up since it implies we would not be able
to remove any cc-option test. Anyway, I admit checking the GCC version
in <linux/compiler-gcc.h> is too late.

Almost at the same time, Linus also suggested to move the compiler
version error to Kconfig time. [2]

I unified the two similar scripts, gcc-version.sh and clang-version.sh
into cc-version.sh. The old scripts invoked the compiler multiple times
(3 times for gcc-version.sh, 4 times for clang-version.sh). I refactored
the code so the new one invokes the compiler just once, and also tried
my best to use shell-builtin commands where possible.

The new script runs faster.

  $ time ./scripts/clang-version.sh clang
  120000

  real    0m0.029s
  user    0m0.012s
  sys     0m0.021s

  $ time ./scripts/cc-version.sh clang
  Clang 120000

  real    0m0.009s
  user    0m0.006s
  sys     0m0.004s

cc-version.sh also shows an error message if the compiler is too old:

  $ make defconfig CC=clang-9
  *** Default configuration is based on 'x86_64_defconfig'
  ***
  *** Compiler is too old.
  ***   Your Clang version:    9.0.1
  ***   Minimum Clang version: 10.0.1
  ***
  scripts/Kconfig.include:46: Sorry, this compiler is not supported.
  make[1]: *** [scripts/kconfig/Makefile:81: defconfig] Error 1
  make: *** [Makefile:602: defconfig] Error 2

The new script takes care of ICC because we have <linux/compiler-intel.h>
although I am not sure if building the kernel with ICC is well-supported.

[1]: https://lore.kernel.org/r/20210110190807.134996-1-paul.gortmaker@windriver.com
[2]: https://lore.kernel.org/r/CAHk-=wh-+TMHPTFo1qs-MYyK7tZh-OQovA=pP3=e06aCVp6_kA@mail.gmail.com

Fixes: 87de84c914 ("kbuild: remove cc-option test of -Werror=date-time")
Reported-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Tested-by: Miguel Ojeda <ojeda@kernel.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-02-16 12:01:32 +09:00
..
atomic
basic
clang-tools scripts/clang-tools: switch explicitly to Python 3 2021-02-03 09:01:08 +09:00
coccinelle
dtc
dummy-tools kbuild: simplify GCC_PLUGINS enablement in dummy-tools/gcc 2021-01-23 18:31:07 +09:00
gcc-plugins gcc-plugins: fix gcc 11 indigestion with plugins... 2021-01-06 15:08:23 -08:00
gdb
genksyms genksyms: Ignore module scoped _Static_assert() 2020-12-21 13:57:08 +09:00
kconfig kconfig: mconf: fix HOSTCC call 2021-01-27 03:17:42 +09:00
ksymoops
mod Kbuild updates for v5.11 2020-12-22 14:02:39 -08:00
package
selinux
tracing
.gitignore
adjust_autoksyms.sh
asn1_compiler.c
bin2c.c
bloat-o-meter scripts: switch explicitly to Python 3 2021-01-22 06:34:44 +09:00
bootgraph.pl
bpf_helpers_doc.py
cc-can-link.sh
cc-version.sh kbuild: check the minimum compiler version in Kconfig 2021-02-16 12:01:32 +09:00
check-sysctl-docs
check_extable.sh
checkincludes.pl
checkkconfigsymbols.py
checkpatch.pl Revert "checkpatch: add check for keyword 'boolean' in Kconfig definitions" 2021-01-28 13:28:58 +09:00
checkstack.pl
checksyscalls.sh
checkversion.pl
cleanfile
cleanpatch
coccicheck scripts: coccicheck: Correct usage of make coccicheck 2020-12-24 12:59:43 +01:00
config kconfig: config script: add a little user help 2021-01-04 10:38:11 +09:00
const_structs.checkpatch
decode_stacktrace.sh
decodecode
depmod.sh depmod: handle the case of /sbin/depmod without /sbin in PATH 2021-01-01 12:26:39 -08:00
dev-needs.sh
diffconfig scripts: switch explicitly to Python 3 2021-01-22 06:34:44 +09:00
documentation-file-ref-check
export_report.pl
extract-cert.c
extract-ikconfig
extract-module-sig.pl
extract-sys-certs.pl
extract-vmlinux
extract_xc3028.pl
faddr2line
file-size.sh
find-unused-docs.sh
gcc-goto.sh
gcc-ld
gcc-x86_32-has-stack-protector.sh
gcc-x86_64-has-stack-protector.sh
gen_autoksyms.sh
gen_ksymdeps.sh
get_abi.pl
get_dvb_firmware
get_feat.pl
get_maintainer.pl
gfp-translate
headerdep.pl
headers_check.pl
headers_install.sh
insert-sys-cert.c
jobserver-exec kbuild: remove PYTHON variable 2021-02-01 10:37:19 +09:00
kallsyms.c kallsyms: fix nonconverging kallsyms table with lld 2021-02-05 17:53:28 +09:00
Kbuild.include
Kconfig.include kbuild: check the minimum compiler version in Kconfig 2021-02-16 12:01:32 +09:00
kernel-doc
ld-version.sh kbuild: LD_VERSION redenomination 2021-02-12 05:12:31 +09:00
leaking_addresses.pl
Lindent
link-vmlinux.sh
lld-version.sh
Makefile scripts: use pkg-config to locate libcrypto 2021-01-28 13:25:33 +09:00
Makefile.asm-generic
Makefile.build
Makefile.clean
Makefile.dtbinst
Makefile.extrawarn
Makefile.gcc-plugins
Makefile.headersinst
Makefile.host
Makefile.kasan
Makefile.kcov
Makefile.kcsan
Makefile.lib kasan, arm64: expand CONFIG_KASAN checks 2020-12-22 12:55:08 -08:00
Makefile.modfinal
Makefile.modinst
Makefile.modpost
Makefile.modsign
Makefile.package
Makefile.ubsan ubsan: move cc-option tests into Kconfig 2020-12-15 22:46:18 -08:00
Makefile.userprogs
makelst
markup_oops.pl
mkcompile_h
mkmakefile
mksysmap
mkuboot.sh
module.lds.S
modules-check.sh
nsdeps
objdiff
parse-maintainers.pl
patch-kernel
profile2linkerlist.pl
prune-kernel
recordmcount.c
recordmcount.h
recordmcount.pl
setlocalversion
show_delta
sign-file.c
sorttable.c
sorttable.h
spdxcheck-test.sh
spdxcheck.py
spelling.txt
sphinx-pre-install
split-man.pl
stackdelta
stackusage
subarch.include
tags.sh
tools-support-relr.sh
unifdef.c
ver_linux
xen-hypercalls.sh
xz_wrap.sh