Re: [PATCH v5 24/31] kconfig: add CC_IS_GCC and GCC_VERSION

From: Stefan Agner
Date: Tue Jun 05 2018 - 04:37:34 EST


On 05.06.2018 08:27, Masahiro Yamada wrote:
> 2018-06-05 14:50 GMT+09:00 Stefan Agner <stefan@xxxxxxxx>:
>> On 05.06.2018 02:07, Masahiro Yamada wrote:
>>> Hi Stefan
>>>
>>> 2018-06-05 6:49 GMT+09:00 Stefan Agner <stefan@xxxxxxxx>:
>>>> Hi Masahiro,
>>>>
>>>> On 28.05.2018 11:22, Masahiro Yamada wrote:
>>>>> This will be useful to specify the required compiler version,
>>>>> like this:
>>>>>
>>>>> config FOO
>>>>> bool "Use Foo"
>>>>> depends on GCC_VERSION >= 40800
>>>>> help
>>>>> This feature requires GCC 4.8 or newer.
>>>>>
>>>>
>>>> I tried using CC_IS_GCC today while using clang. It seems that it is set
>>>> to y despite I am using CC=clang.
>>>>
>>>> .config looks like this after config:
>>>>
>>>> ...
>>>> CONFIG_CC_IS_GCC=y
>>>> CONFIG_GCC_VERSION=40201
>>>> CONFIG_CC_IS_CLANG=y
>>>> CONFIG_CLANG_VERSION=60000
>>>> ...
>>>>
>>>>
>>>> I am using clang 6.0.0 on Arch Linux, which seems to return a version
>>>> when using gcc-version.sh:
>>>> ./scripts/gcc-version.sh clang | sed 's/^0*//'
>>>> 402
>>>>
>>>> I guess that should not be the case?
>>>>
>>>
>>>
>>> What will 'clang --version' print on your machine?
>>
>> $ clang --version
>> clang version 6.0.0 (tags/RELEASE_600/final)
>> Target: x86_64-pc-linux-gnu
>> Thread model: posix
>> InstalledDir:
>> /home/ags/gcc-linaro-7.2.1-2017.11-x86_64_arm-linux-gnueabihf/bin
>>
>> I use a symlink to clang in my cross compiler toolchain, that is why
>> InstalledDir points to a GCC toolchain.
>>
>
> Ah, I see.
>
>
> I will fix it up like follows:
>
>
> diff --git a/init/Kconfig b/init/Kconfig
> index e5a0d89..efc43c6 100644
> --- a/init/Kconfig
> +++ b/init/Kconfig
> @@ -9,7 +9,7 @@ config DEFCONFIG_LIST
> default "arch/$(ARCH)/defconfig"
>
> config CC_IS_GCC
> - def_bool $(success,$(CC) --version | grep -q gcc)
> + def_bool $(success,$(CC) --version | head -n 1 | grep -q gcc)

Yes that works for me:

...
CONFIG_GCC_VERSION=0

CONFIG_CC_IS_CLANG=y

CONFIG_CLANG_VERSION=60000
...

--
Stefan

>
> config GCC_VERSION
> int
> @@ -17,7 +17,7 @@ config GCC_VERSION
> default 0
>
> config CC_IS_CLANG
> - def_bool $(success,$(CC) --version | grep -q clang)
> + def_bool $(success,$(CC) --version | head -n 1 | grep -q clang)
>
> config CLANG_VERSION
> int
>
>
>
>
> Best Regards
> Masahiro Yamada