[Buildroot] [PATCH v2] toolchain: add a harmless link when sysroot detection is not accurate

[Romain Naour <romain.naour@gmail.com>]

Hi Vicente,

Le 02/02/2016 11:57, Vicente Olivert Riera a ?crit :
> ping
> 
> Currently Codescape MIPS toolchains are broken for big-endian. This patch fixes
> the problem.
> 
> On 22/01/16 16:05, Vicente Olivert Riera wrote:
>> Sometimes is not possible to detect if the sysroots are nested or side
>> by side. For instance this happens for MIPS big endian, where the
>> sysroot and the arch-sysroot directories are the same. Examples:

By sometime, you mean toolchains generated by Crosstool-ng and Buildroot which
doesn't support multi-lib.

>>
>> === Mentor Sourcery CodeBench toolchain
>>
>> $ readlink -f $(LANG=C mips-linux-gnu-gcc -print-file-name=libc.a) | sed
>> -r -e 's:(usr/)?lib(32|64)?([^/]*)?/([^/]*/)?libc\.a::'
>> /toolchains/mips-2015.11/mips-linux-gnu/libc/
>>
>> $ readlink -f $(LANG=C mips-linux-gnu-gcc -EB -print-file-name=libc.a) |
>> sed -r -e 's:(usr/)?lib(32|64)?([^/]*)?/([^/]*/)?libc\.a::'
>> /toolchains/mips-2015.11/mips-linux-gnu/libc/
>>
>> === Codescape toolchain
>>
>> $ readlink -f $(LANG=C mips-img-linux-gnu-gcc -print-file-name=libc.a) |
>> sed -r -e 's:(usr/)?lib(32|64)?([^/]*)?/([^/]*/)?libc\.a::'
>> /toolchains/mips-img-linux-gnu/2015.06-05/sysroot/mips-r6-hard/
>>
>> $ readlink -f $(LANG=C mips-img-linux-gnu-gcc -EB
>> -print-file-name=libc.a) | sed -r -e
>> 's:(usr/)?lib(32|64)?([^/]*)?/([^/]*/)?libc\.a::'
>> /toolchains/mips-img-linux-gnu/2015.06-05/sysroot/mips-r6-hard/
>>
>> For those cases where the sysroot detection is not accurate we add a
>> harmless symlink necessary for certain toolchains such as Codescape for
>> MIPS. The other toolchains in this situation (unknown sysroot layout)
>> don't need this symlink to work, but as stated before, this symlink is
>> harmless.

Since Codescape are supported in Buildroot as external toolchain and the issue
appear only with it for BE, you can probability use a
TOOLCHAIN_EXTERNAL_POST_INSTALL_STAGING_HOOKS like for some Linaro toolchains
instead ?

Thoughts ?

>>
>> Signed-off-by: Vicente Olivert Riera <Vincent.Riera@imgtec.com>
>> ---
>> Changes v1 -> v2:
>>   - Update the comment above the copy_toolchain_sysroot function.
>>   - Explain in the commit log which toolchains are affected and provide
>>     some outputs of -print-file-name to explain the problem.
>>     (Both changes requested by Thomas Petazzoni)
>>
>>   toolchain/helpers.mk | 16 ++++++++++++++++
>>   1 file changed, 16 insertions(+)
>>
>> diff --git a/toolchain/helpers.mk b/toolchain/helpers.mk
>> index 70695ee..c8245f7 100644
>> --- a/toolchain/helpers.mk
>> +++ b/toolchain/helpers.mk
>> @@ -130,6 +130,12 @@ copy_toolchain_lib_root = \
>>   #
>>   # * Create a symbolic link
>>   #
>> +# If we are in the situation where we don't know if the sysroot layout
>> +# is nested of side by side, we:
>> +#
>> +# * Create a symbolic link because it's harmless and is necessary for
>> +#   certain toolchains like Codescape for MIPS.
>> +#
>>   # Finally, some toolchains (i.e Linaro binary toolchains) store
>>   # support libraries (libstdc++, libgcc_s) outside of the sysroot, so
>>   # we simply copy all the libraries from the "support lib directory"
>> @@ -160,9 +166,12 @@ copy_toolchain_sysroot = \
>>       done ; \
>>       SYSROOT_DIR_CANON=`readlink -f $${SYSROOT_DIR}` ; \
>>       ARCH_SYSROOT_DIR_CANON=`readlink -f $${ARCH_SYSROOT_DIR}` ; \
>> +    echo "SYSROOT_DIR_CANON: $${ARCH_SYSROOT_DIR_CANON}" ; \

should be SYSROOT_DIR_CANON

Best regards,
Romain

>> +    echo "ARCH_SYSROOT_DIR_CANON: $${ARCH_SYSROOT_DIR_CANON}" ; \
>>       if [ $${SYSROOT_DIR_CANON} != $${ARCH_SYSROOT_DIR_CANON} ] ; then \
>>           relpath="./" ; \
>>           if [ $${ARCH_SYSROOT_DIR_CANON:0:$${\#SYSROOT_DIR_CANON}} ==
>> $${SYSROOT_DIR_CANON} ] ; then \
>> +            echo "Nested sysroots detected." ; \
>>               if [ ! -d $${ARCH_SYSROOT_DIR}/usr/include ] ; then \
>>                   cp -a $${SYSROOT_DIR}/usr/include $(STAGING_DIR)/usr ; \
>>               fi ; \
>> @@ -174,9 +183,16 @@ copy_toolchain_sysroot = \
>>               ln -s $${relpath} $(STAGING_DIR)/$${ARCH_SUBDIR} ; \
>>               echo "Symlinking $(STAGING_DIR)/$${ARCH_SUBDIR} -> $${relpath}" ; \
>>           elif [ `dirname $${ARCH_SYSROOT_DIR_CANON}` == `dirname
>> $${SYSROOT_DIR_CANON}` ] ; then \
>> +            echo "Side by side sysroots detected." ; \
>>               ln -snf $${relpath} $(STAGING_DIR)/`basename
>> $${ARCH_SYSROOT_DIR_CANON}` ; \
>>               echo "Symlinking $(STAGING_DIR)/`basename
>> $${ARCH_SYSROOT_DIR_CANON}` -> $${relpath}" ; \
>>           fi ; \
>> +    else \
>> +        relpath="./" ; \
>> +        echo "Unable to detect if sysroots are nested or side by side." ; \
>> +        echo "Creating a harmless symlink necessary for certain toolchains." ; \
>> +        ln -snf $${relpath} $(STAGING_DIR)/`basename
>> $${ARCH_SYSROOT_DIR_CANON}` ; \
>> +        echo "Symlinking $(STAGING_DIR)/`basename $${ARCH_SYSROOT_DIR_CANON}`
>> -> $${relpath}" ; \
>>       fi ; \
>>       if test -n "$${SUPPORT_LIB_DIR}" ; then \
>>           cp -a $${SUPPORT_LIB_DIR}/* $(STAGING_DIR)/lib/ ; \
>>
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