2021-01-14 18:11:11

by Masahiro Yamada

[permalink] [raw]
Subject: [PATCH v3] 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 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 not supported.
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.

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://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

Fixes: 87de84c9140e ("kbuild: remove cc-option test of -Werror=date-time")
Reported-by: Paul Gortmaker <[email protected]>
Suggested-by: Linus Torvalds <[email protected]>
Signed-off-by: Masahiro Yamada <[email protected]>
---

Changes in v3:
- add $(srctree)/ to fix out-of-tree build
- support ICC version

Changes in v2:
- fix the function name

include/linux/compiler-clang.h | 10 -----
init/Kconfig | 9 ++--
scripts/Kconfig.include | 6 +++
scripts/cc-version.sh | 76 ++++++++++++++++++++++++++++++++++
scripts/clang-version.sh | 19 ---------
scripts/gcc-version.sh | 20 ---------
6 files changed, 87 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..26c355a84c19 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 := $(shell,$(srctree)/scripts/cc-version.sh $(CC))
+$(error-if,$(success,test -z "$(cc-info)"),Sorry$(comma) this compiler is not supported.)
+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..818d233bb0ad
--- /dev/null
+++ b/scripts/cc-version.sh
@@ -0,0 +1,76 @@
+#!/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
+icc_min_version=16.0.3 # temporary
+
+# print the compiler name and versions
+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)
+ ICC __INTEL_COMPILER __INTEL_COMPILER_UPDATE
+ #elif defined(__GNUC__)
+ GCC __GNUC__ __GNUC_MINOR__ __GNUC_PATCHLEVEL__
+ #else
+ unknown
+ #endif
+ EOF
+}
+
+# convert the version string x.y.z to a canonical 5 or 6-digit form
+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=$1
+
+case "$name" in
+GCC)
+ version=$2.$3.$4
+ min_version=$gcc_min_version
+ ;;
+Clang)
+ version=$2.$3.$4
+ min_version=$clang_min_version
+ ;;
+ICC)
+ version=$(($2 / 100)).$(($2 % 100)).$3
+ min_version=$icc_min_version
+ ;;
+*)
+ echo "$orig_args: unknown compiler" >&2
+ exit 1
+ ;;
+esac
+
+cversion=$(get_canonical_version $version)
+min_cversion=$(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
+
+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


2021-01-14 18:24:52

by Nathan Chancellor

[permalink] [raw]
Subject: Re: [PATCH v3] kbuild: check the minimum compiler version in Kconfig

On Fri, Jan 15, 2021 at 03:07:09AM +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 not supported.
> 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.
>
> 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://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
>
> Fixes: 87de84c9140e ("kbuild: remove cc-option test of -Werror=date-time")
> Reported-by: Paul Gortmaker <[email protected]>
> Suggested-by: Linus Torvalds <[email protected]>
> Signed-off-by: Masahiro Yamada <[email protected]>

Reviewed-by: Nathan Chancellor <[email protected]>
Tested-by: Nathan Chancellor <[email protected]>

2021-01-14 18:25:46

by Nick Desaulniers

[permalink] [raw]
Subject: Re: [PATCH v3] kbuild: check the minimum compiler version in Kconfig

On Thu, Jan 14, 2021 at 10:07 AM Masahiro Yamada <[email protected]> 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 not supported.
> 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.
>
> 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://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

Consider Nathan's request to use lore links rather than lkml.org links.
https://lore.kernel.org/lkml/20210114170710.GA259754@ubuntu-m3-large-x86/
But I don't think that requires a v4 just for that.

Thanks for the patch.

Reviewed-by: Nick Desaulniers <[email protected]>
Tested-by: Nick Desaulniers <[email protected]>

>
> Fixes: 87de84c9140e ("kbuild: remove cc-option test of -Werror=date-time")
> Reported-by: Paul Gortmaker <[email protected]>
> Suggested-by: Linus Torvalds <[email protected]>
> Signed-off-by: Masahiro Yamada <[email protected]>
> ---
>
> Changes in v3:
> - add $(srctree)/ to fix out-of-tree build
> - support ICC version
>
> Changes in v2:
> - fix the function name
>
> include/linux/compiler-clang.h | 10 -----
> init/Kconfig | 9 ++--
> scripts/Kconfig.include | 6 +++
> scripts/cc-version.sh | 76 ++++++++++++++++++++++++++++++++++
> scripts/clang-version.sh | 19 ---------
> scripts/gcc-version.sh | 20 ---------
> 6 files changed, 87 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..26c355a84c19 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 := $(shell,$(srctree)/scripts/cc-version.sh $(CC))
> +$(error-if,$(success,test -z "$(cc-info)"),Sorry$(comma) this compiler is not supported.)
> +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..818d233bb0ad
> --- /dev/null
> +++ b/scripts/cc-version.sh
> @@ -0,0 +1,76 @@
> +#!/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
> +icc_min_version=16.0.3 # temporary
> +
> +# print the compiler name and versions
> +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)
> + ICC __INTEL_COMPILER __INTEL_COMPILER_UPDATE
> + #elif defined(__GNUC__)
> + GCC __GNUC__ __GNUC_MINOR__ __GNUC_PATCHLEVEL__
> + #else
> + unknown
> + #endif
> + EOF
> +}
> +
> +# convert the version string x.y.z to a canonical 5 or 6-digit form
> +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=$1
> +
> +case "$name" in
> +GCC)
> + version=$2.$3.$4
> + min_version=$gcc_min_version
> + ;;
> +Clang)
> + version=$2.$3.$4
> + min_version=$clang_min_version
> + ;;
> +ICC)
> + version=$(($2 / 100)).$(($2 % 100)).$3
> + min_version=$icc_min_version
> + ;;
> +*)
> + echo "$orig_args: unknown compiler" >&2
> + exit 1
> + ;;
> +esac
> +
> +cversion=$(get_canonical_version $version)
> +min_cversion=$(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
> +
> +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
>


--
Thanks,
~Nick Desaulniers

2021-01-14 18:36:07

by Miguel Ojeda

[permalink] [raw]
Subject: Re: [PATCH v3] kbuild: check the minimum compiler version in Kconfig

On Thu, Jan 14, 2021 at 7:08 PM Masahiro Yamada <[email protected]> wrote:
>
> 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.

Tested v3 with GCC, Clang and an old GCC too:

$ scripts/cc-version.sh gcc-4.6.4
***
*** Compiler is too old.
*** Your GCC version: 4.6.4
*** Minimum GCC version: 4.9.0
***

Reviewed-by: Miguel Ojeda <[email protected]>
Tested-by: Miguel Ojeda <[email protected]>

Cheers,
Miguel