linux/scripts
Masahiro Yamada 64a91907c8 kbuild: refactor scripts/Makefile.extrawarn
Instead of the warning-[123] magic, let's accumulate compiler options
to KBUILD_CFLAGS directly as the top Makefile does. I think this makes
it easier to understand what is going on in this file.

This commit slightly changes the behavior, I think all of which are OK.

[1] Currently, cc-option calls are needlessly evaluated. For example,
      warning-3 += $(call cc-option, -Wpacked-bitfield-compat)
    needs evaluating only when W=3, but it is actually evaluated for
    W=1, W=2 as well. With this commit, only relevant cc-option calls
    will be evaluated. This is a slight optimization.

[2] Currently, unsupported level like W=4 is checked by:
      $(error W=$(KBUILD_ENABLE_EXTRA_GCC_CHECKS) is unknown)
    This will no longer be checked, but I do not think it is a big
    deal.

[3] Currently, 4 Clang warnings (Winitializer-overrides, Wformat,
    Wsign-compare, Wformat-zero-length) are shown by any of W=1, W=2,
    and W=3. With this commit, they will be warned only by W=1. I
    think this is a more correct behavior since each warning belongs
    to only one group.

For understanding this commit correctly:

We have 3 warning groups, W=1, W=2, and W=3. You may think W=3 has a
higher level than W=1, but they are actually independent. If you like,
you can combine them like W=13. To enable all the warnings, you can
pass W=123. It is shown by 'make help', but not noticed much. Since we
support W= combination, there should not exist intersection among the
three groups. If we enable Winitializer-overrides for W=1, we do not
need to for W=2 or W=3. This is the reason why I think the change [3]
makes sense.

The documentation says -Winitializer-overrides is enabled by default.
(https://clang.llvm.org/docs/DiagnosticsReference.html#winitializer-overrides)
We negate it by passing -Wno-initializer-overrides for the normal
build, but we do not do that for W=1. This means, W=1 effectively
enables -Winitializer-overrides by the clang's default. The same for
the other three.

Add comments in case people are confused with the code.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Acked-by: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
2019-09-06 23:46:52 +09:00
..
atomic locking/atomics: Use sed(1) instead of non-standard head(1) option 2019-06-25 10:17:07 +02:00
basic kbuild: remove unneeded comments and code from scripts/basic/Makefile 2019-08-29 23:54:29 +09:00
coccinelle Kbuild updates for v5.3 (2nd) 2019-07-20 09:34:55 -07:00
dtc Devicetree updates for v5.3: 2019-07-11 18:35:30 -07:00
gcc-plugins docs: move gcc_plugins.txt to core-api and rename to .rst 2019-07-15 09:20:27 -03:00
gdb scripts/gdb: add helpers to find and list devices 2019-07-16 19:23:24 -07:00
genksyms kbuild: make bison create C file and header in a single pattern rule 2019-08-14 01:10:42 +09:00
kconfig merge_config.sh: ignore unwanted grep errors 2019-09-04 23:12:50 +09:00
ksymoops
mod modpost: add NOFAIL to strndup 2019-09-04 22:55:42 +09:00
package kbuild: pkg: rename scripts/package/Makefile to scripts/Makefile.package 2019-08-25 07:42:00 +09:00
selinux treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156 2019-05-30 11:26:35 -07:00
tracing treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 166 2019-05-30 11:26:39 -07:00
.gitignore scripts: remove unnecessary ihex2fw and check-lc_ctypes from .gitignore 2018-12-22 00:37:52 +09:00
Kbuild.include kbuild: remove unused objectify macro 2019-07-27 12:18:19 +09:00
Kconfig.include kbuild: Fail if gold linker is detected 2019-08-14 01:10:42 +09:00
Lindent
Makefile kbuild: pkg: clean up package files/dirs from the top Makefile 2019-08-25 07:39:21 +09:00
Makefile.asm-generic kbuild: force all architectures except um to include mandatory-y 2019-03-17 12:56:32 +09:00
Makefile.build kbuild: move modkern_{c,a}flags to Makefile.lib from Makefile.build 2019-08-22 01:14:11 +09:00
Makefile.clean kbuild: clean up subdir-ymn calculation in Makefile.clean 2019-08-29 23:54:29 +09:00
Makefile.dtbinst
Makefile.extrawarn kbuild: refactor scripts/Makefile.extrawarn 2019-09-06 23:46:52 +09:00
Makefile.gcc-plugins gcc-plugins: structleak: Generalize to all variable types 2019-03-04 09:29:41 -08:00
Makefile.headersinst kbuild: fix 'No such file or directory' warning for headers_install 2019-06-24 03:43:03 +09:00
Makefile.host kbuild: change *FLAGS_<basetarget>.o to take the path relative to $(obj) 2019-09-04 23:12:50 +09:00
Makefile.kasan kasan: remove use after scope bugs detection. 2019-03-05 21:07:13 -08:00
Makefile.kcov treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Makefile.lib kbuild: change *FLAGS_<basetarget>.o to take the path relative to $(obj) 2019-09-04 23:12:50 +09:00
Makefile.modbuiltin kbuild: get rid of kernel/ prefix from in-tree modules.{order,builtin} 2019-07-17 22:39:27 +09:00
Makefile.modfinal kbuild: move modkern_{c,a}flags to Makefile.lib from Makefile.build 2019-08-22 01:14:11 +09:00
Makefile.modinst kbuild: modinst: read modules.order instead of $(MODVERDIR)/*.mod 2019-07-17 22:39:27 +09:00
Makefile.modpost kbuild: split final module linking out into Makefile.modfinal 2019-08-22 01:08:15 +09:00
Makefile.modsign kbuild: modsign: read modules.order instead of $(MODVERDIR)/*.mod 2019-07-17 22:39:27 +09:00
Makefile.package kbuild: pkg: rename scripts/package/Makefile to scripts/Makefile.package 2019-08-25 07:42:00 +09:00
Makefile.ubsan ubsan: Remove vla bound checks. 2019-05-06 11:12:09 -07:00
adjust_autoksyms.sh kbuild: remove the first line of *.mod files 2019-07-18 02:19:31 +09:00
asn1_compiler.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 36 2019-05-24 17:27:11 +02:00
bin2c.c
bloat-o-meter bloat-o-meter: ignore __addressable_ symbols 2018-12-28 12:11:44 -08:00
bootgraph.pl treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 391 2019-06-05 17:37:11 +02:00
bpf_helpers_doc.py bpf: fix script for generating man page on BPF helpers 2019-05-13 01:12:45 +02:00
cc-can-link.sh
check_extable.sh
checkincludes.pl
checkkconfigsymbols.py treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 166 2019-05-30 11:26:39 -07:00
checkpatch.pl checkpatch.pl: warn on duplicate sysctl local variable 2019-07-16 19:23:22 -07:00
checkstack.pl scripts/checkstack.pl: Fix arm64 wrong or unknown architecture 2019-06-05 02:33:10 +09:00
checksyscalls.sh checksyscalls: fix up mq_timedreceive and stat exceptions 2019-02-19 21:27:53 +01:00
checkversion.pl
clang-version.sh kbuild: update comment block of scripts/clang-version.sh 2019-03-04 22:34:54 +09:00
cleanfile
cleanpatch
coccicheck
config
conmakehash.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 54 2019-05-24 17:36:42 +02:00
const_structs.checkpatch
decode_stacktrace.sh scripts/decode_stacktrace: Accept dash/underscore in modules 2019-07-12 11:05:41 -07:00
decodecode scripts/decodecode: set ARCH when running natively on arm/arm64 2018-12-28 12:11:44 -08:00
depmod.sh kbuild: modules_install: warn when missing System.map file 2018-09-09 09:14:07 +09:00
diffconfig
documentation-file-ref-check scripts/documentation-file-ref-check: ignore output dir 2019-06-14 14:43:01 -06:00
export_report.pl kbuild: export_report: read modules.order instead of .tmp_versions/*.mod 2019-07-18 02:19:31 +09:00
extract-cert.c
extract-ikconfig
extract-module-sig.pl
extract-sys-certs.pl
extract-vmlinux treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 378 2019-06-05 17:37:10 +02:00
extract_xc3028.pl treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 339 2019-06-05 17:37:07 +02:00
faddr2line scripts/faddr2line: fix location of start_kernel in comment 2018-11-18 10:15:09 -08:00
file-size.sh
find-unused-docs.sh
gcc-goto.sh jump_label: move 'asm goto' support test to Kconfig 2019-01-06 09:46:51 +09:00
gcc-ld
gcc-plugin.sh
gcc-version.sh kbuild: clean up scripts/gcc-version.sh 2019-03-04 22:35:04 +09:00
gcc-x86_32-has-stack-protector.sh
gcc-x86_64-has-stack-protector.sh
gen_compile_commands.py gen_compile_commands: lower the entry count threshold 2019-07-27 12:18:19 +09:00
gen_ksymdeps.sh kbuild: simplify dependency generation for CONFIG_TRIM_UNUSED_KSYMS 2018-12-01 23:13:14 +09:00
get_abi.pl doc: ABI scripts: add a SPDX header file 2019-06-21 16:58:37 +02:00
get_dvb_firmware treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 61 2019-05-24 17:36:45 +02:00
get_maintainer.pl get_maintainer: add ability to skip moderated mailing lists 2019-07-16 19:23:22 -07:00
gfp-translate treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 166 2019-05-30 11:26:39 -07:00
headerdep.pl
headers_check.pl
headers_install.sh kbuild: re-implement detection of CONFIG options leaked to user-space 2019-08-21 21:05:21 +09:00
insert-sys-cert.c
kallsyms.c kallsyms: exclude kasan local symbols on s390 2019-07-08 02:25:59 +09:00
kernel-doc kernel-doc: Don't try to mark up function names 2019-06-26 11:14:15 -06:00
ld-version.sh
leaking_addresses.pl treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 166 2019-05-30 11:26:39 -07:00
link-vmlinux.sh kbuild: Parameterize kallsyms generation and correct reporting 2019-08-21 21:05:21 +09:00
makelst
markup_oops.pl treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 373 2019-06-05 17:37:10 +02:00
mkcompile_h Kbuild: Handle PREEMPT_RT for version string and magic 2019-08-14 01:10:42 +09:00
mkmakefile kbuild: get rid of $(realpath ...) from scripts/mkmakefile 2019-08-29 23:54:29 +09:00
mksysmap
mkuboot.sh
module-common.lds
modules-check.sh kbuild: get rid of kernel/ prefix from in-tree modules.{order,builtin} 2019-07-17 22:39:27 +09:00
namespace.pl
objdiff treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 199 2019-05-30 11:29:23 -07:00
parse-maintainers.pl
patch-kernel
pnmtologo.c
profile2linkerlist.pl
prune-kernel
recordmcount.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 378 2019-06-05 17:37:10 +02:00
recordmcount.h powerpc updates for 5.3 2019-07-13 16:08:36 -07:00
recordmcount.pl treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 166 2019-05-30 11:26:39 -07:00
setlocalversion scripts/setlocalversion: Improve -dirty check with git-status --no-optional-locks 2018-11-21 23:57:33 +09:00
show_delta treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 438 2019-06-05 17:37:17 +02:00
sign-file.c
sortextable.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 378 2019-06-05 17:37:10 +02:00
sortextable.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 378 2019-06-05 17:37:10 +02:00
spdxcheck-test.sh scripts: add spdxcheck.py self test 2018-12-28 12:11:44 -08:00
spdxcheck.py spdxcheck.py: fix directory structures 2019-06-01 15:51:31 -07:00
spelling.txt scripts/spelling.txt: add more spellings to spelling.txt 2019-07-12 11:05:41 -07:00
sphinx-pre-install scripts/sphinx-pre-install: seek for Noto CJK fonts for pdf output 2019-07-17 06:57:52 -03:00
split-man.pl
stackdelta
stackusage
subarch.include selftests: add headers_install to lib.mk 2018-09-05 08:12:09 -06:00
tags.sh kbuild: add a flag to force absolute path for srctree 2019-07-11 00:05:09 +09:00
unifdef.c unifdef: use memcpy instead of strncpy 2018-11-30 14:45:01 -08:00
ver_linux ver_linux: Assign constant RE to variable name for clarity 2019-01-22 13:34:35 +01:00
xen-hypercalls.sh
xz_wrap.sh