/* DWARF2 EH unwinding support for Blackfin.
   Copyright (C) 2007 Free Software Foundation, Inc.

This file is part of GCC.

GCC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

In addition to the permissions in the GNU General Public License, the
Free Software Foundation gives you unlimited permission to link the
compiled version of this file with other programs, and to distribute
those programs without any restriction coming from the use of this
file.  (The General Public License restrictions do apply in other
respects; for example, they cover modification of the file, and
distribution when not linked into another program.)

GCC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING.  If not, write to
the Free Software Foundation, 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301, USA.  */

/* Do code reading to identify a signal frame, and set the frame
   state data appropriately.  See unwind-dw2.c for the structs.
   Don't use this at all if inhibit_libc is used.  */

#ifndef inhibit_libc

#include <signal.h>
#include <sys/ucontext.h>

#define MD_FALLBACK_FRAME_STATE_FOR bfin_fallback_frame_state

static _Unwind_Reason_Code
bfin_fallback_frame_state (struct _Unwind_Context *context,
			   _Unwind_FrameState *fs)
{
  unsigned char *pc = context->ra;
  struct sigcontext *sc;
  long new_cfa;

  /* P0=__NR_rt_sigreturn (X); EXCPT  0x0; */
  if (*(unsigned short *)pc == 0xe128
      && *(unsigned short *)(pc + 2) == 0x00ad
      && *(unsigned short *)(pc + 4) == 0x00a0)
    {
      struct rt_sigframe {
	int sig;
	struct siginfo *pinfo;
	void *puc;
	char retcode[8];
	struct siginfo info;
	struct ucontext uc;
      } *rt_ = context->cfa;

      /* The void * cast is necessary to avoid an aliasing warning.
         The aliasing warning is correct, but should not be a problem
         because it does not alias anything.  */
      sc = (struct sigcontext *)(void *)&rt_->uc.uc_mcontext.gregs;
    }
  else
    return _URC_END_OF_STACK;

  new_cfa = sc->sc_usp;
  fs->regs.cfa_how = CFA_REG_OFFSET;
  fs->regs.cfa_reg = 14;
  fs->regs.cfa_offset = new_cfa - (long) context->cfa;

  fs->regs.reg[0].how = REG_SAVED_OFFSET;
  fs->regs.reg[0].loc.offset = (long)&sc->sc_r0 - new_cfa;
  fs->regs.reg[1].how = REG_SAVED_OFFSET;
  fs->regs.reg[1].loc.offset = (long)&sc->sc_r1 - new_cfa;
  fs->regs.reg[2].how = REG_SAVED_OFFSET;
  fs->regs.reg[2].loc.offset = (long)&sc->sc_r2 - new_cfa;
  fs->regs.reg[3].how = REG_SAVED_OFFSET;
  fs->regs.reg[3].loc.offset = (long)&sc->sc_r3 - new_cfa;
  fs->regs.reg[4].how = REG_SAVED_OFFSET;
  fs->regs.reg[4].loc.offset = (long)&sc->sc_r4 - new_cfa;
  fs->regs.reg[5].how = REG_SAVED_OFFSET;
  fs->regs.reg[5].loc.offset = (long)&sc->sc_r5 - new_cfa;
  fs->regs.reg[6].how = REG_SAVED_OFFSET;
  fs->regs.reg[6].loc.offset = (long)&sc->sc_r6 - new_cfa;
  fs->regs.reg[7].how = REG_SAVED_OFFSET;
  fs->regs.reg[7].loc.offset = (long)&sc->sc_r7 - new_cfa;
  fs->regs.reg[8].how = REG_SAVED_OFFSET;
  fs->regs.reg[8].loc.offset = (long)&sc->sc_p0 - new_cfa;
  fs->regs.reg[9].how = REG_SAVED_OFFSET;
  fs->regs.reg[9].loc.offset = (long)&sc->sc_p1 - new_cfa;
  fs->regs.reg[10].how = REG_SAVED_OFFSET;
  fs->regs.reg[10].loc.offset = (long)&sc->sc_p2 - new_cfa;
  fs->regs.reg[11].how = REG_SAVED_OFFSET;
  fs->regs.reg[11].loc.offset = (long)&sc->sc_p3 - new_cfa;
  fs->regs.reg[12].how = REG_SAVED_OFFSET;
  fs->regs.reg[12].loc.offset = (long)&sc->sc_p4 - new_cfa;
  fs->regs.reg[13].how = REG_SAVED_OFFSET;
  fs->regs.reg[13].loc.offset = (long)&sc->sc_p5 - new_cfa;

  fs->regs.reg[15].how = REG_SAVED_OFFSET;
  fs->regs.reg[15].loc.offset = (long)&sc->sc_fp - new_cfa;
  fs->regs.reg[16].how = REG_SAVED_OFFSET;
  fs->regs.reg[16].loc.offset = (long)&sc->sc_i0 - new_cfa;
  fs->regs.reg[17].how = REG_SAVED_OFFSET;
  fs->regs.reg[17].loc.offset = (long)&sc->sc_i1 - new_cfa;
  fs->regs.reg[18].how = REG_SAVED_OFFSET;
  fs->regs.reg[18].loc.offset = (long)&sc->sc_i2 - new_cfa;
  fs->regs.reg[19].how = REG_SAVED_OFFSET;
  fs->regs.reg[19].loc.offset = (long)&sc->sc_i3 - new_cfa;
  fs->regs.reg[20].how = REG_SAVED_OFFSET;
  fs->regs.reg[20].loc.offset = (long)&sc->sc_b0 - new_cfa;
  fs->regs.reg[21].how = REG_SAVED_OFFSET;
  fs->regs.reg[21].loc.offset = (long)&sc->sc_b1 - new_cfa;
  fs->regs.reg[22].how = REG_SAVED_OFFSET;
  fs->regs.reg[22].loc.offset = (long)&sc->sc_b2 - new_cfa;
  fs->regs.reg[23].how = REG_SAVED_OFFSET;
  fs->regs.reg[23].loc.offset = (long)&sc->sc_b3 - new_cfa;
  fs->regs.reg[24].how = REG_SAVED_OFFSET;
  fs->regs.reg[24].loc.offset = (long)&sc->sc_l0 - new_cfa;
  fs->regs.reg[25].how = REG_SAVED_OFFSET;
  fs->regs.reg[25].loc.offset = (long)&sc->sc_l1 - new_cfa;
  fs->regs.reg[26].how = REG_SAVED_OFFSET;
  fs->regs.reg[26].loc.offset = (long)&sc->sc_l2 - new_cfa;
  fs->regs.reg[27].how = REG_SAVED_OFFSET;
  fs->regs.reg[27].loc.offset = (long)&sc->sc_l3 - new_cfa;
  fs->regs.reg[28].how = REG_SAVED_OFFSET;
  fs->regs.reg[28].loc.offset = (long)&sc->sc_m0 - new_cfa;
  fs->regs.reg[29].how = REG_SAVED_OFFSET;
  fs->regs.reg[29].loc.offset = (long)&sc->sc_m1 - new_cfa;
  fs->regs.reg[30].how = REG_SAVED_OFFSET;
  fs->regs.reg[30].loc.offset = (long)&sc->sc_m2 - new_cfa;
  fs->regs.reg[31].how = REG_SAVED_OFFSET;
  fs->regs.reg[31].loc.offset = (long)&sc->sc_m3 - new_cfa;
  /* FIXME: Handle A0, A1, CC.  */
  fs->regs.reg[35].how = REG_SAVED_OFFSET;
  fs->regs.reg[35].loc.offset = (long)&sc->sc_rets - new_cfa;
  fs->regs.reg[36].how = REG_SAVED_OFFSET;
  fs->regs.reg[36].loc.offset = (long)&sc->sc_pc - new_cfa;
  fs->regs.reg[37].how = REG_SAVED_OFFSET;
  fs->regs.reg[37].loc.offset = (long)&sc->sc_retx - new_cfa;

  fs->regs.reg[40].how = REG_SAVED_OFFSET;
  fs->regs.reg[40].loc.offset = (long)&sc->sc_astat - new_cfa;
  fs->regs.reg[41].how = REG_SAVED_OFFSET;
  fs->regs.reg[41].loc.offset = (long)&sc->sc_seqstat - new_cfa;

  fs->regs.reg[44].how = REG_SAVED_OFFSET;
  fs->regs.reg[44].loc.offset = (long)&sc->sc_lt0 - new_cfa;
  fs->regs.reg[45].how = REG_SAVED_OFFSET;
  fs->regs.reg[45].loc.offset = (long)&sc->sc_lt1 - new_cfa;
  fs->regs.reg[46].how = REG_SAVED_OFFSET;
  fs->regs.reg[46].loc.offset = (long)&sc->sc_lc0 - new_cfa;
  fs->regs.reg[47].how = REG_SAVED_OFFSET;
  fs->regs.reg[47].loc.offset = (long)&sc->sc_lc1 - new_cfa;
  fs->regs.reg[48].how = REG_SAVED_OFFSET;
  fs->regs.reg[48].loc.offset = (long)&sc->sc_lb0 - new_cfa;
  fs->regs.reg[49].how = REG_SAVED_OFFSET;
  fs->regs.reg[49].loc.offset = (long)&sc->sc_lb1 - new_cfa;
  fs->retaddr_column = 35;

  return _URC_NO_REASON;
}

#endif /* ifdef inhibit_libc */