Re: [PATCH] Makefile: remove stale cc-option checks

[Naresh Kamboju <naresh.kamboju@linaro.org>]

On Wed, 11 Aug 2021 at 02:12, Nick Desaulniers <ndesaulniers@google.com> wrote:
>
> cc-option, cc-option-yn, and cc-disable-warning all invoke the compiler
> during build time, and can slow down the build when these checks become
> stale for our supported compilers, whose minimally supported versions
> increases over time. See Documentation/process/changes.rst for the
> current supported minimal versions (GCC 4.9+, clang 10.0.1+). Compiler
> version support for these flags may be verified on godbolt.org.
>
> The following flags are GCC only and supported since at least GCC 4.9.
> Remove cc-option and cc-disable-warning tests.
> * -fno-tree-loop-im
> * -Wno-maybe-uninitialized
> * -fno-reorder-blocks
> * -fno-ipa-cp-clone
> * -fno-partial-inlining
> * -femit-struct-debug-baseonly
> * -fno-inline-functions-called-once
> * -fconserve-stack
>
> The following flags are supported by all supported versions of GCC and
> Clang. Remove their cc-option, cc-option-yn, and cc-disable-warning tests.
> * -fno-delete-null-pointer-checks
> * -fno-var-tracking
> * -mfentry
> * -Wno-array-bounds
>
> The following configs are made dependent on GCC, since they use GCC
> specific flags.
> * READABLE_ASM
> * DEBUG_SECTION_MISMATCH
>
> --param=allow-store-data-races=0 was renamed to --allow-store-data-races
> in the GCC 10 release.

[Please ignore this if it is already reported]

Linux next 20210813 tag s390 build failed with gcc-8 but pass with
gcc-9 and gcc-10.

 s390 (defconfig) with gcc-8 FAILED
 s390 (defconfig) with gcc-9 PASS
 s390 (defconfig) with gcc-10 PASS

Build error:
-----------
s390x-linux-gnu-gcc: error: unrecognized command line option
'-mfentry'; did you mean '--entry'?
make[2]: *** [/builds/linux/scripts/Makefile.build:272:
scripts/mod/empty.o] Error 1
s390x-linux-gnu-gcc: error: unrecognized command line option
'-mfentry'; did you mean '--entry'?
make[2]: *** [/builds/linux/scripts/Makefile.build:118:
scripts/mod/devicetable-offsets.s] Error 1
make[2]: Target '__build' not remade because of errors.

Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>

Build log,
https://builds.tuxbuild.com/1wfNcaYbsp29k3RvYuPXzxrM4vs/

metadata:
--------
    git_describe: next-20210813
    git_repo: https://gitlab.com/Linaro/lkft/mirrors/next/linux-next
    git_short_log: 4b358aabb93a (\Add linux-next specific files for 20210813\)
    target_arch: s390
    toolchain: gcc-8


Steps to reproduce:
-------------------
# TuxMake is a command line tool and Python library that provides
# portable and repeatable Linux kernel builds across a variety of
# architectures, toolchains, kernel configurations, and make targets.
#
# TuxMake supports the concept of runtimes.
# See https://docs.tuxmake.org/runtimes/, for that to work it requires
# that you install podman or docker on your system.
#
# To install tuxmake on your system globally:
# sudo pip3 install -U tuxmake
#
# See https://docs.tuxmake.org/ for complete documentation.


tuxmake --runtime podman --target-arch s390 --toolchain gcc-8
--kconfig defconfig


--
Linaro LKFT
https://lkft.linaro.org