/* Definitions for PA_RISC with ELF-32 format
   Copyright (C) 2000, 2002 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.

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, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

/* Turn off various SOM crap we don't want.  */
#undef TARGET_ELF32
#define TARGET_ELF32 1

/* The libcall __canonicalize_funcptr_for_compare is referenced in
   crtend.o and the reference isn't resolved in objects that don't
   compare function pointers.  Thus, we need to play games to provide
   a reference in crtbegin.o.  The rest of the define is the same
   as that in crtstuff.c  */
#define CTOR_LIST_BEGIN \
  asm (".type __canonicalize_funcptr_for_compare,@function\n"		\
"	.text\n"							\
"	.word __canonicalize_funcptr_for_compare-$PIC_pcrel$0");	\
  STATIC func_ptr __CTOR_LIST__[1]					\
    __attribute__ ((__unused__, section(".ctors"),			\
		    aligned(sizeof(func_ptr))))				\
    = { (func_ptr) (-1) }

/* Do code reading to identify a signal frame, and set the frame
   state data appropriately.  See unwind-dw2.c for the structs.  */

#ifdef IN_LIBGCC2
#include <signal.h>
#include <sys/ucontext.h>

/* Unfortunately, because of various bugs and changes to the kernel,
   we have several cases to deal with.

   In 2.4, the signal trampoline is 4 words, and (CONTEXT)->ra should
   point directly at the beginning of the trampoline and struct rt_sigframe.

   In <= 2.6.5-rc2-pa3, the signal trampoline is 9 words, and 
   (CONTEXT)->ra points at the 4th word in the trampoline structure.  This 
   is wrong, it should point at the 5th word.  This is fixed in 2.6.5-rc2-pa4.

   To detect these cases, we first take (CONTEXT)->ra, align it to 64-bytes
   to get the beginning of the signal frame, and then check offsets 0, 4
   and 5 to see if we found the beginning of the trampoline.  This will
   tell us how to locate the sigcontext structure.

   Note that with a 2.4 64-bit kernel, the signal context is not properly
   passed back to userspace so the unwind will not work correctly.  */
#define MD_FALLBACK_FRAME_STATE_FOR(CONTEXT, FS, SUCCESS)		\
  do {									\
    unsigned long sp = (unsigned long)(CONTEXT)->ra & ~63;		\
    unsigned int *pc = (unsigned int *)sp;				\
    unsigned long off;							\
    _Unwind_Ptr new_cfa;						\
    int i;								\
    struct sigcontext *sc;						\
    struct rt_sigframe {						\
      struct siginfo info;						\
      struct ucontext uc;						\
    } *frame;								\
									\
    /* rt_sigreturn trampoline: 					\
       3419000x ldi 0, %r25 or ldi 1, %r25   (x = 0 or 2)  		\
       3414015a ldi __NR_rt_sigreturn, %r20 				\
       e4008200 be,l 0x100(%sr2, %r0), %sr0, %r31 			\
       08000240 nop  */							\
    									\
    if (pc[0] == 0x34190000 || pc[0] == 0x34190002)			\
      off = 4*4;							\
    else if (pc[4] == 0x34190000 || pc[4] == 0x34190002)		\
      {									\
	pc += 4;							\
	off = 10 * 4;							\
      }									\
    else if (pc[5] == 0x34190000 || pc[5] == 0x34190002)		\
      {									\
	pc += 5;							\
	off = 10 * 4;							\
      }									\
    else								\
      break;								\
    if (pc[1] != 0x3414015a 						\
	|| pc[2] != 0xe4008200 						\
	|| pc[3] != 0x08000240)						\
      break;								\
									\
    frame = (struct rt_sigframe *)(sp + off);				\
    sc = &frame->uc.uc_mcontext;					\
									\
    new_cfa = sc->sc_gr[30];						\
    (FS)->cfa_how = CFA_REG_OFFSET;					\
    (FS)->cfa_reg = 30;							\
    (FS)->cfa_offset = new_cfa - (long) (CONTEXT)->cfa;			\
    for (i = 1; i <= 31; i++)						\
      {									\
	(FS)->regs.reg[i].how = REG_SAVED_OFFSET;			\
	(FS)->regs.reg[i].loc.offset = (long)&sc->sc_gr[i] - new_cfa;	\
      }									\
    for (i = 4; i <= 31; i++)						\
      {									\
	/* FP regs have left and right halves */			\
	(FS)->regs.reg[2*i+24].how = REG_SAVED_OFFSET;			\
	(FS)->regs.reg[2*i+24].loc.offset				\
	  = (long)&sc->sc_fr[i] - new_cfa;				\
	(FS)->regs.reg[2*i+24+1].how = REG_SAVED_OFFSET;		\
	(FS)->regs.reg[2*i+24+1].loc.offset				\
	  = (long)&sc->sc_fr[i] + 4 - new_cfa;				\
      }									\
    (FS)->regs.reg[88].how = REG_SAVED_OFFSET;				\
    (FS)->regs.reg[88].loc.offset = (long) &sc->sc_sar - new_cfa;	\
    (FS)->regs.reg[2].how = REG_SAVED_OFFSET;				\
    (FS)->regs.reg[2].loc.offset = (long) &sc->sc_iaoq[0] - new_cfa;	\
    (FS)->retaddr_column = 2;						\
    goto SUCCESS;							\
  } while (0)

#endif /* IN_LIBGCC2 */