GNAT, SJLJ and zero-cost exception handling

[Eric Botcazou]

> I'd like to know how I should go about building GCC such that I can choose
> between SJLJ and ZCX at compile time, using --rts=sjlj.

$srcdir/configure --enable-languages=ada --disable-libada
make [bootstrap]
make -C gcc gnatlib-sjlj
make install
in the $prefix/lib/gcc/$target/$version directory:
 - create 'sjlj' subdir
 - move 'adainclude' and 'adalib' subdirs to 'sjlj' subdir
rm gcc/stamp-gnatlib*
make -C gcc gnatlib-shared gnattools
make install

You need GCC 3.x or GCC 4.2 for GNAT SJLJ exceptions to work.

> From [2] it looks like this is a configure-time option only.

[2] describes GCC SJLJ, which is not the same as GNAT SJLJ.

-- 
Eric Botcazou