[Buildroot] [PATCH] toolchain-external: add a specific check to avoid Angstrom toolchains

Thomas De Schampheleire patrickdepinguin at gmail.com
Sun Oct 13 07:29:12 UTC 2013


Hi Thomas,

On Sat, Oct 12, 2013 at 12:14 PM, Thomas Petazzoni
<thomas.petazzoni at free-electrons.com> wrote:
> The Angstrom toolchains available at
> http://www.angstrom-distribution.org/toolchains/ are not usable as
> external toolchains in Buildroot, because they are not pure toolchains
> with just the C library, but instead complete SDKs with many
> cross-compiled libraries (Gtk, Qt, glib, neon, sqlite, X.org, and many
> more, approximately 200 MB of libraries).
>
> Buildroot cannot use such toolchains, and while this is documented in
> our manual, some users still try to do this. Today, one such user came
> on the IRC channel, reporting a build problem, which we started
> investigating, only to realize after a long time that he was using an
> Angstrom toolchain.
>
> To avoid this problem in the future, we explicitly check if the
> toolchain is from Angstrom by looking at the vendor part of the tuple
> exposed by the toolchain: as soon as it is
> <something>-angstrom-<something-else>, we reject the toolchain with an
> explanation.
>
> Signed-off-by: Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
> ---
>  toolchain/helpers.mk                               | 18 ++++++++++++++++++
>  toolchain/toolchain-external/toolchain-external.mk |  1 +
>  2 files changed, 19 insertions(+)
>
> diff --git a/toolchain/helpers.mk b/toolchain/helpers.mk
> index 95120cd..d81e561 100644
> --- a/toolchain/helpers.mk
> +++ b/toolchain/helpers.mk
> @@ -324,3 +324,21 @@ check_cross_compiler_exists = \
>                 echo "Cannot execute cross-compiler '$${__CROSS_CC}'" ; \
>                 exit 1 ; \
>         fi
> +
> +#
> +# Check for toolchains known to not work with Buildroot. To check for

I think it is more common to say 'known not to work' (nit)

> +# Angstrom toolchains, we're taking the "Target: " line in the output
> +# of gcc -v, and look at the vendor part of the tuple.

Is there a reason why you're not using 'gcc -dumpmachine'?
This directly prints the tuple...

> +#
> +# $1: cross-gcc path
> +#
> +check_wrong_toolchain = \

This is just nitting about names, but I find 'wrong' odd here. What
about 'unusable'?

> +       __CROSS_CC=$(strip $1) ; \
> +       vendor=`$${__CROSS_CC} -v 2>&1 | sed -n '/^Target/s/Target: [^-]*-\([^-]*\)-.*/\1/p'` ; \
> +       if test $${vendor} = "angstrom" ; then \

I think that you should put $${vendor}} in quotes here. Suppose it
returns an empty string for one reason or the other, then you'll get a
syntax failure.

> +               echo "Angstrom toolchains are not pure toolchains: they contain" ; \
> +               echo "many other libraries than just the C library, which makes" ; \
> +               echo "them unsuitable as external toolchains for build systems" ; \
> +               echo "such as Buildroot" ; \
> +               exit 1 ; \
> +       fi
> diff --git a/toolchain/toolchain-external/toolchain-external.mk b/toolchain/toolchain-external/toolchain-external.mk
> index b5b1ce7..102bcfd 100644
> --- a/toolchain/toolchain-external/toolchain-external.mk
> +++ b/toolchain/toolchain-external/toolchain-external.mk
> @@ -371,6 +371,7 @@ endif
>  # type of C library and all C library features.
>  define TOOLCHAIN_EXTERNAL_CONFIGURE_CMDS
>         $(Q)$(call check_cross_compiler_exists,$(TOOLCHAIN_EXTERNAL_CC))
> +       $(Q)$(call check_wrong_toolchain,$(TOOLCHAIN_EXTERNAL_CC))
>         $(Q)LIBC_A_LOCATION=`readlink -f $$(LANG=C $(TOOLCHAIN_EXTERNAL_CC) -print-file-name=libc.a)` ; \
>         SYSROOT_DIR=`echo $${LIBC_A_LOCATION} | sed -r -e 's:(usr/)?lib(32|64)?/(.*/)?libc\.a::'` ; \
>         if test -z "$${SYSROOT_DIR}" ; then \


Best regards,
Thomas



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