On Mon, 2010-09-27 at 11:12 +0200, Olivier Hainque wrote: > Hello Luke, > > Luke A. Guest wrote: > > I'm having a look into getting DWARF2 exceptions (ZCX) working on ARM. > > Thanks :-)
Well, I'm reading as much as I can regarding this, but finding it hard to work some things out. I've been reading through: http://gcc.gnu.org/ml/gcc/2004-03/msg01779.html and trying some example code in C++ and Ada, but it doesn't seem to match up in some places, i.e. no calls into __register_frame_info() yet the libgcc_eh.so contains the function. > > Any pointers would be gratefully received. I'm fairly sure I know where > > to start. > > A few general points, jic. > > The first thing will be to adjust your target system.ads to > have GCC_ZCX_Support := True, then use the gnatlib-zcx Makefile > target, with essentially two effects: adjust your target system.ads > further to switch the GCC_ZCX_Support to True as well, and arrange > to build/link with the "-gcc" variants of a-exexpr.adb and raise.c. Yup, aware of this so far. > The system.ads changes control the compiler to declare eh regions, produce > dwarf eh info etc. Yup. > The use of -gcc variants is for the runtime library, switching to the > libgcc services for exception propagations. > > raise-gcc.c hosts the Ada personality routine, where a number of changes > will be needed I believe. Also, I think tracebak.c is where the ARM specific routine(s) will need to go, included from another file tb-armlinux.c? I think this will be required as (if I'm right), different ARM CPU's have differing number of registers, and I think I read in the ARM docs that float regs won't need to be saved if they're not used. I could be wrong about this though. > There, please, I'd rather have the ARM specializations abstracted as > much as possible, e.g. with new functions and alternate implementations, > instead of provided as #ifdefs blocks spread within existing functions. Well, I think that's possible to a point, obviously some things will have to go into ifdef's unfortunately (it's not Ada :D). Hopefully, I can rely on some help from you AdaCore guys? This is my first foray into GCC internals :/ Thanks, Luke.
