Building cross-toolchain for microblaze

[Adhemerval Zanella]

On 04/11/2016 00:48, Joseph Myers wrote:
> Continuing the issues shown up by writing a script to build glibc for all 
> ABIs, I find that MicroBlaze glibc does not build using the final compiler 
> because MicroBlaze GCC always uses SJLJ exceptions (see 
> gcc/common/config/microblaze/microblaze-common.c defining 
> TARGET_EXCEPT_UNWIND_INFO to sjlj_except_unwind_info), which is not 
> supported in glibc, resulting in undefined references to _Unwind_SjLj_* 
> (glibc deliberately links with libgcc.a and *not* libgcc_eh.a and gets EH 
> functionality via loading libgcc_s as needed, which is not implemented for 
> the SJLJ case; in the static-only case there isn't a separate libgcc_eh so 
> a build with the initial static-only compiler works accidentally).
> 
> How is building MicroBlaze glibc meant to work?  Is there some GCC patch 
> missing upstream to use DWARF2 exceptions?
> 

I could build a workable toolchain, at least for glibc building, by
configuring GCC with both '--disable-sjlj-exceptions'  and 
'--disable-shared'.  I did not dig into the issue, but it was already
reported on maillist this same issue.