[RFC/CFT] Hookize TARGET_UNWIND_INFO and related macros

[Steve Ellcey]

Richard,

I finally has some time to test this patch on IA64 HP-UX and Linux and I
got build failures on both systems.  Using a preprocessed version of
libgcov.c I see:

 $ obj_gcc/gcc/cc1 -mlp64 -O2 -g -quiet x.i
x.i: In function 'gcov_exit':
x.i:3169:1: internal compiler error: in dwarf2out_frame_debug_expr, at
dwarf2out.c:2304
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.

Looks like it is failing on this assert:

             /* Saving a register in a register.  */
              gcc_assert (!fixed_regs [REGNO (dest)]
                          /* For the SPARC and its register window.  */
                          || (DWARF_FRAME_REGNUM (REGNO (src))
                              == DWARF_FRAME_RETURN_COLUMN));

It looks like both src and dest are:

(reg/f:DI 12 r12)

and r12 is listed in FIXED_REGISTERS as the stack pointer.

Steve Ellcey
sje@cup.hp.com