gcc/config/alpha/linux-unwind.h

   1 /* DWARF2 EH unwinding support for Alpha Linux.
   2    Copyright (C) 2004, 2005 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 In addition to the permissions in the GNU General Public License, the
  12 Free Software Foundation gives you unlimited permission to link the
  13 compiled version of this file with other programs, and to distribute
  14 those programs without any restriction coming from the use of this
  15 file.  (The General Public License restrictions do apply in other
  16 respects; for example, they cover modification of the file, and
  17 distribution when not linked into another program.)
  18
  19 GCC is distributed in the hope that it will be useful,
  20 but WITHOUT ANY WARRANTY; without even the implied warranty of
  21 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22 GNU General Public License for more details.
  23
  24 You should have received a copy of the GNU General Public License
  25 along with GCC; see the file COPYING.  If not, write to
  26 the Free Software Foundation, 59 Temple Place - Suite 330,
  27 Boston, MA 02111-1307, USA.  */
  28
  29 /* Do code reading to identify a signal frame, and set the frame
  30    state data appropriately.  See unwind-dw2.c for the structs.  */
  31
  32 #include <signal.h>
  33 #include <sys/ucontext.h>
  34
  35 #define MD_FALLBACK_FRAME_STATE_FOR alpha_fallback_frame_state
  36
  37 static _Unwind_Reason_Code
  38 alpha_fallback_frame_state (struct _Unwind_Context *context,
  39                             _Unwind_FrameState *fs)
  40 {
  41   unsigned int *pc = context->ra;
  42   struct sigcontext *sc;
  43   long new_cfa, i;
  44
  45   if (pc[0] != 0x47fe0410               /* mov $30,$16 */
  46       || pc[2] != 0x00000083            /* callsys */)
  47     return _URC_END_OF_STACK;
  48   if (context->cfa == 0)
  49     return _URC_END_OF_STACK;
  50   if (pc[1] == 0x201f0067)              /* lda $0,NR_sigreturn */
  51     sc = context->cfa;
  52   else if (pc[1] == 0x201f015f) /* lda $0,NR_rt_sigreturn */
  53     {
  54       struct rt_sigframe {
  55         struct siginfo info;
  56         struct ucontext uc;
  57       } *rt_ = context->cfa;
  58       sc = &rt_->uc.uc_mcontext;
  59     }
  60   else
  61     return _URC_END_OF_STACK;
  62   new_cfa = sc->sc_regs[30];
  63   fs->cfa_how = CFA_REG_OFFSET;
  64   fs->cfa_reg = 30;
  65   fs->cfa_offset = new_cfa - (long) context->cfa;
  66   for (i = 0; i < 30; ++i)
  67     {
  68       fs->regs.reg[i].how = REG_SAVED_OFFSET;
  69       fs->regs.reg[i].loc.offset
  70         = (long)&sc->sc_regs[i] - new_cfa;
  71     }
  72   for (i = 0; i < 31; ++i)
  73     {
  74       fs->regs.reg[i+32].how = REG_SAVED_OFFSET;
  75       fs->regs.reg[i+32].loc.offset
  76         = (long)&sc->sc_fpregs[i] - new_cfa;
  77     }
  78   fs->regs.reg[64].how = REG_SAVED_OFFSET;
  79   fs->regs.reg[64].loc.offset = (long)&sc->sc_pc - new_cfa;
  80   fs->retaddr_column = 64;
  81   return _URC_NO_REASON;
  82 }