On Thu, Jan 14, 2021 at 01:24:19PM +0900, Masahiro Yamada wrote: > 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 similar two scripts, gcc-version.sh and clang-version.sh > into the new 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 > > The cc-version.sh also shows the error if the compiler is 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 unsupported. > make[1]: *** [scripts/kconfig/Makefile:81: defconfig] Error 1 > make: *** [Makefile:602: defconfig] Error 2 > > I removed the clang version check from <linux/compiler-clang.h> > > For now, I did not touch <linux/compiler-gcc.h> in order to avoid > merge conflict with [3], which has been queued up in the arm64 tree. > We will be able to clean it up later. > > I put the stub for ICC because I see <linux/compiler-intel.h> although > I am not sure if building the kernel with ICC is well-supported. > > [1] https://lkml.org/lkml/2021/1/10/250 > [2] https://lkml.org/lkml/2021/1/12/1708 > [3] https://lkml.org/lkml/2021/1/12/1533 I would recommend the lore version of these links: [1]: https://lore.kernel.org/r/20210110190807.134996-1-paul.gortmaker@xxxxxxxxxxxxx [2]: https://lore.kernel.org/r/CAHk-=wh-+TMHPTFo1qs-MYyK7tZh-OQovA=pP3=e06aCVp6_kA@xxxxxxxxxxxxxx [3]: https://lore.kernel.org/r/20210112224832.10980-1-will@xxxxxxxxxx > Fixes: 87de84c9140e ("kbuild: remove cc-option test of -Werror=date-time") > Reported-by: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx> > Suggested-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> > Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx> I like this a lot, I think that erroring as early as possible when something is misconfigured is a good user experience. Reviewed-by: Nathan Chancellor <natechancellor@xxxxxxxxx> Tested-by: Nathan Chancellor <natechancellor@xxxxxxxxx> > --- > > Changes in v2: > - fix the function name > > include/linux/compiler-clang.h | 10 ----- > init/Kconfig | 9 +++-- > scripts/Kconfig.include | 6 +++ > scripts/cc-version.sh | 69 ++++++++++++++++++++++++++++++++++ > scripts/clang-version.sh | 19 ---------- > scripts/gcc-version.sh | 20 ---------- > 6 files changed, 80 insertions(+), 53 deletions(-) > create mode 100755 scripts/cc-version.sh > delete mode 100755 scripts/clang-version.sh > delete mode 100755 scripts/gcc-version.sh > > diff --git a/include/linux/compiler-clang.h b/include/linux/compiler-clang.h > index 98cff1b4b088..04c0a5a717f7 100644 > --- a/include/linux/compiler-clang.h > +++ b/include/linux/compiler-clang.h > @@ -3,16 +3,6 @@ > #error "Please don't include <linux/compiler-clang.h> directly, include <linux/compiler.h> instead." > #endif > > -#define CLANG_VERSION (__clang_major__ * 10000 \ > - + __clang_minor__ * 100 \ > - + __clang_patchlevel__) > - > -#if CLANG_VERSION < 100001 > -#ifndef __BPF_TRACING__ > -# error Sorry, your version of Clang is too old - please use 10.0.1 or newer. > -#endif > -#endif > - > /* Compiler specific definitions for Clang compiler */ > > /* same as gcc, this was present in clang-2.6 so we can assume it works > diff --git a/init/Kconfig b/init/Kconfig > index b77c60f8b963..01108dd1318b 100644 > --- a/init/Kconfig > +++ b/init/Kconfig > @@ -26,11 +26,11 @@ config CC_VERSION_TEXT > and then every file will be rebuilt. > > config CC_IS_GCC > - def_bool $(success,echo "$(CC_VERSION_TEXT)" | grep -q gcc) > + def_bool $(success,test $(cc-name) = GCC) > > config GCC_VERSION > int > - default $(shell,$(srctree)/scripts/gcc-version.sh $(CC)) if CC_IS_GCC > + default $(cc-version) if CC_IS_GCC > default 0 > > config LD_VERSION > @@ -38,14 +38,15 @@ config LD_VERSION > default $(shell,$(LD) --version | $(srctree)/scripts/ld-version.sh) > > config CC_IS_CLANG > - def_bool $(success,echo "$(CC_VERSION_TEXT)" | grep -q clang) > + def_bool $(success,test $(cc-name) = Clang) > > config LD_IS_LLD > def_bool $(success,$(LD) -v | head -n 1 | grep -q LLD) > > config CLANG_VERSION > int > - default $(shell,$(srctree)/scripts/clang-version.sh $(CC)) > + default $(cc-version) if CC_IS_CLANG > + default 0 > > config LLD_VERSION > int > diff --git a/scripts/Kconfig.include b/scripts/Kconfig.include > index a5fe72c504ff..cdc8726d2904 100644 > --- a/scripts/Kconfig.include > +++ b/scripts/Kconfig.include > @@ -39,6 +39,12 @@ as-instr = $(success,printf "%b\n" "$(1)" | $(CC) $(CLANG_FLAGS) -c -x assembler > $(error-if,$(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 unsupported. > +cc-info := $(shell,scripts/cc-version.sh $(CC)) > +$(error-if,$(success,test -z "$(cc-info)"),Sorry$(comma) this compiler is unsupported.) > +cc-name := $(shell,set -- $(cc-info); echo $1) > +cc-version := $(shell,set -- $(cc-info); echo $2) > + > # Fail if the linker is gold as it's not capable of linking the kernel proper > $(error-if,$(success, $(LD) -v | grep -q gold), gold linker '$(LD)' not supported) > > diff --git a/scripts/cc-version.sh b/scripts/cc-version.sh > new file mode 100755 > index 000000000000..9c17c1de401c > --- /dev/null > +++ b/scripts/cc-version.sh > @@ -0,0 +1,69 @@ > +#!/bin/sh > +# SPDX-License-Identifier: GPL-2.0 > +# > +# Print the compiler name and its version in a 5 or 6-digit form. > +# Also, perform the minimum version check. > + > +set -e > + > +# When you raise the compiler version, please update > +# Documentation/process/changes.rst as well. > +gcc_min_version=4.9.0 > +clang_min_version=10.0.1 > + > +# print the compiler name, major version, minor version, patchlevel version > +get_compiler_info() > +{ > + cat <<- EOF | "$@" -E -P -x c - 2>/dev/null > + #if defined(__clang__) > + Clang __clang_major__ __clang_minor__ __clang_patchlevel__ > + #elif defined(__INTEL_COMPILER) > + /* How to get the version of intel compiler? */ > + ICC 0 0 0 > + #elif defined(__GNUC__) > + GCC __GNUC__ __GNUC_MINOR__ __GNUC_PATCHLEVEL__ > + #else > + unsupported 0 0 0 > + #endif > + EOF > +} > + > +# convert the version to a canonical 5 or 6-digit form for numerical comparison > +get_canonical_version() > +{ > + IFS=. > + set -- $1 > + echo $((10000 * $1 + 100 * $2 + $3)) > +} > + > +# $@ instead of $1 because multiple words might be given e.g. CC="ccache gcc" > +orig_args="$@" > +set -- $(get_compiler_info "$@") > + > +name=$1 > +version=$2.$3.$4 > + > +case "$name" in > +GCC) min_version=$gcc_min_version;; > +Clang) min_version=$clang_min_version;; > +ICC) ;; # ICC min version undefined? > +*) echo "$orig_args: unknown compiler" >&2; exit 1;; > +esac > + > +cversion=$(get_canonical_version $version) > + > +if [ -n "$min_version" ]; then > + > + min_cversion=$(get_canonical_version $min_version) > + > + if [ "$cversion" -lt "$min_cversion" ]; then > + echo >&2 "***" > + echo >&2 "*** Compiler is too old." > + echo >&2 "*** Your $name version: $version" > + echo >&2 "*** Minimum $name version: $min_version" > + echo >&2 "***" > + exit 1 > + fi > +fi > + > +echo $name $cversion > diff --git a/scripts/clang-version.sh b/scripts/clang-version.sh > deleted file mode 100755 > index 6fabf0695761..000000000000 > --- a/scripts/clang-version.sh > +++ /dev/null > @@ -1,19 +0,0 @@ > -#!/bin/sh > -# SPDX-License-Identifier: GPL-2.0 > -# > -# clang-version clang-command > -# > -# Print the compiler version of `clang-command' in a 5 or 6-digit form > -# such as `50001' for clang-5.0.1 etc. > - > -compiler="$*" > - > -if ! ( $compiler --version | grep -q clang) ; then > - echo 0 > - exit 1 > -fi > - > -MAJOR=$(echo __clang_major__ | $compiler -E -x c - | tail -n 1) > -MINOR=$(echo __clang_minor__ | $compiler -E -x c - | tail -n 1) > -PATCHLEVEL=$(echo __clang_patchlevel__ | $compiler -E -x c - | tail -n 1) > -printf "%d%02d%02d\\n" $MAJOR $MINOR $PATCHLEVEL > diff --git a/scripts/gcc-version.sh b/scripts/gcc-version.sh > deleted file mode 100755 > index ae353432539b..000000000000 > --- a/scripts/gcc-version.sh > +++ /dev/null > @@ -1,20 +0,0 @@ > -#!/bin/sh > -# SPDX-License-Identifier: GPL-2.0 > -# > -# gcc-version gcc-command > -# > -# Print the gcc version of `gcc-command' in a 5 or 6-digit form > -# such as `29503' for gcc-2.95.3, `30301' for gcc-3.3.1, etc. > - > -compiler="$*" > - > -if [ ${#compiler} -eq 0 ]; then > - echo "Error: No compiler specified." >&2 > - printf "Usage:\n\t$0 <gcc-command>\n" >&2 > - exit 1 > -fi > - > -MAJOR=$(echo __GNUC__ | $compiler -E -x c - | tail -n 1) > -MINOR=$(echo __GNUC_MINOR__ | $compiler -E -x c - | tail -n 1) > -PATCHLEVEL=$(echo __GNUC_PATCHLEVEL__ | $compiler -E -x c - | tail -n 1) > -printf "%d%02d%02d\\n" $MAJOR $MINOR $PATCHLEVEL > -- > 2.27.0 >
