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/****************************************************************************

 *                                                                          *

 *                         GNAT COMPILER COMPONENTS                         *

 *                                                                          *

 *                T R A C E B A C K - A l p h a / V x W o r k s             *

 *                                                                          *

 *                          C Implementation File                           *

 *                                                                          *

 *                     Copyright (C) 2000-2006, AdaCore                     *

 *                                                                          *

 * GNAT is free software;  you can  redistribute it  and/or modify it under *

 * terms of the  GNU General Public License as published  by the Free Soft- *

 * ware  Foundation;  either version 2,  or (at your option) any later ver- *

 * sion.  GNAT is distributed in the hope that it will be useful, but WITH- *

 * OUT 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  distributed with GNAT;  see file COPYING.  If not, write *

 * to  the  Free Software Foundation,  51  Franklin  Street,  Fifth  Floor, *

 * Boston, MA 02110-1301, USA.                                              *

 *                                                                          *

 * As a  special  exception,  if you  link  this file  with other  files to *

 * produce an executable,  this file does not by itself cause the resulting *

 * executable to be covered by the GNU General Public License. This except- *

 * ion does not  however invalidate  any other reasons  why the  executable *

 * file might be covered by the  GNU Public License.                        *

 *                                                                          *

 * GNAT was originally developed  by the GNAT team at  New York University. *

 * Extensive contributions were provided by Ada Core Technologies Inc.      *

 *                                                                          *

 ****************************************************************************/

/* Alpha vxWorks requires a special, complex treatment that is extracted

   from GDB. This file is #included within tracebak.c in the appropriate

   case.  */

#include <stddef.h>

#include <stdlib.h>

#include <limits.h>

#include <string.h>

extern void kerTaskEntry(void);

/* We still use a number of macros similar to the ones for the generic

   __gnat_backtrace implementation.  */

#define SKIP_FRAME 1

#define PC_ADJUST -4

#define STOP_FRAME \

   (current == NULL \

    || ((CORE_ADDR) &kerTaskEntry >= PROC_LOW_ADDR (current->proc_desc) \

        && current->pc >= (CORE_ADDR) &kerTaskEntry))

/* Register numbers of various important registers.

   Note that most of these values are "real" register numbers,

   and correspond to the general registers of the machine,

   and FP_REGNUM is a "phony" register number which is too large

   to be an actual register number as far as the user is concerned

   but serves to get the desired value when passed to read_register.  */

#define T7_REGNUM 8             /* Return address register for OSF/1 __add* */

#define GCC_FP_REGNUM 15        /* Used by gcc as frame register */

#define T9_REGNUM 23            /* Return address register for OSF/1 __div* */

#define SP_REGNUM 30            /* Contains address of top of stack */

#define RA_REGNUM 26            /* Contains return address value */

#define FP0_REGNUM 32           /* Floating point register 0 */

#define PC_REGNUM 64            /* Contains program counter */

#define NUM_REGS 66

#define VM_MIN_ADDRESS (CORE_ADDR)0x120000000

#define SIZEOF_FRAME_SAVED_REGS (sizeof (CORE_ADDR) * (NUM_REGS))

#define INIT_EXTRA_FRAME_INFO(fromleaf, fci) init_extra_frame_info(fci)

#define FRAME_CHAIN(thisframe) (CORE_ADDR) alpha_frame_chain (thisframe)

#define FRAME_CHAIN_VALID(CHAIN, THISFRAME)     \

  ((CHAIN) != 0                                  \

   && !inside_entry_file (FRAME_SAVED_PC (THISFRAME)))

#define FRAME_SAVED_PC(FRAME)   (alpha_frame_saved_pc (FRAME))

#define FRAME_CHAIN_COMBINE(CHAIN, THISFRAME) (CHAIN)

#define INIT_FRAME_PC(FROMLEAF, PREV)

#define INIT_FRAME_PC_FIRST(FROMLEAF, PREV) \

  (PREV)->pc = ((FROMLEAF) ? SAVED_PC_AFTER_CALL ((PREV)->next) \

                : (PREV)->next ? FRAME_SAVED_PC ((PREV)->next) : read_pc ());

#define SAVED_PC_AFTER_CALL(FRAME)      alpha_saved_pc_after_call (FRAME)

typedef unsigned long long int bfd_vma;

typedef bfd_vma CORE_ADDR;

typedef struct pdr

{

  bfd_vma adr;          /* memory address of start of procedure */

  long  isym;           /* start of local symbol entries */

  long  iline;          /* start of line number entries*/

  long  regmask;        /* save register mask */

  long  regoffset;      /* save register offset */

  long  iopt;           /* start of optimization symbol entries*/

  long  fregmask;       /* save floating point register mask */

  long  fregoffset;     /* save floating point register offset */

  long  frameoffset;    /* frame size */

  short framereg;       /* frame pointer register */

  short pcreg;          /* offset or reg of return pc */

  long  lnLow;          /* lowest line in the procedure */

  long  lnHigh;         /* highest line in the procedure */

  bfd_vma cbLineOffset; /* byte offset for this procedure from the fd base */

  /* These fields are new for 64 bit ECOFF.  */

  unsigned gp_prologue : 8; /* byte size of GP prologue */

  unsigned gp_used : 1; /* true if the procedure uses GP */

  unsigned reg_frame : 1; /* true if register frame procedure */

  unsigned prof : 1;    /* true if compiled with -pg */

  unsigned reserved : 13; /* reserved: must be zero */

  unsigned localoff : 8; /* offset of local variables from vfp */

} PDR;

typedef struct alpha_extra_func_info

{

  long numargs;         /* number of args to procedure (was iopt) */

  PDR pdr;                      /* Procedure descriptor record */

}

*alpha_extra_func_info_t;

struct frame_info

{

  /* Nominal address of the frame described.  See comments at FRAME_FP

     about what this means outside the *FRAME* macros; in the *FRAME*

     macros, it can mean whatever makes most sense for this machine.  */

  CORE_ADDR frame;

  /* Address at which execution is occurring in this frame.  For the

     innermost frame, it's the current pc.  For other frames, it is a

     pc saved in the next frame.  */

  CORE_ADDR pc;

  /* For each register, address of where it was saved on entry to the

     frame, or zero if it was not saved on entry to this frame.  This

     includes special registers such as pc and fp saved in special

     ways in the stack frame.  The SP_REGNUM is even more special, the

     address here is the sp for the next frame, not the address where

     the sp was saved.  Allocated by frame_saved_regs_zalloc () which

     is called and initialized by FRAME_INIT_SAVED_REGS. */

  CORE_ADDR *saved_regs;        /*NUM_REGS */

  int localoff;

  int pc_reg;

  alpha_extra_func_info_t proc_desc;

  /* Pointers to the next and previous frame_info's in the frame cache.  */

  struct frame_info *next, *prev;

};

struct frame_saved_regs

{

  /* For each register R (except the SP), regs[R] is the address at

     which it was saved on entry to the frame, or zero if it was not

     saved on entry to this frame.  This includes special registers

     such as pc and fp saved in special ways in the stack frame.

     regs[SP_REGNUM] is different.  It holds the actual SP, not the

     address at which it was saved.  */

  CORE_ADDR regs[NUM_REGS];

};

static CORE_ADDR theRegisters[32];

/* Prototypes for local functions. */

static CORE_ADDR read_next_frame_reg (struct frame_info *, int);

static CORE_ADDR heuristic_proc_start (CORE_ADDR);

static int alpha_about_to_return (CORE_ADDR pc);

static void init_extra_frame_info (struct frame_info *);

static CORE_ADDR alpha_frame_chain (struct frame_info *);

static CORE_ADDR alpha_frame_saved_pc (struct frame_info *frame);

static void *trace_alloc (unsigned int);

static struct frame_info *create_new_frame (CORE_ADDR, CORE_ADDR);

static alpha_extra_func_info_t

heuristic_proc_desc (CORE_ADDR, CORE_ADDR, struct frame_info *,

                     struct frame_saved_regs *);

static alpha_extra_func_info_t

find_proc_desc (CORE_ADDR, struct frame_info *, struct frame_saved_regs *);

/* Heuristic_proc_start may hunt through the text section for a long

   time across a 2400 baud serial line.  Allows the user to limit this

   search.  */

static unsigned int heuristic_fence_post = 1<<16;

/* Layout of a stack frame on the alpha:

                |                               |

 pdr members:   |  7th ... nth arg,             |

                |  `pushed' by caller.          |

                |                               |

----------------|-------------------------------|<--  old_sp == vfp

   ^  ^  ^  ^   |                               |

   |  |  |  |   |                               |

   |  |localoff |  Copies of 1st .. 6th         |

   |  |  |  |   |  argument if necessary.       |

   |  |  |  v   |                               |

   |  |  |  --- |-------------------------------|<-- FRAME_LOCALS_ADDRESS

   |  |  |      |                               |

   |  |  |      |  Locals and temporaries.      |

   |  |  |      |                               |

   |  |  |      |-------------------------------|

   |  |  |      |                               |

   |-fregoffset |  Saved float registers.       |

   |  |  |      |  F9                           |

   |  |  |      |   .                           |

   |  |  |      |   .                           |

   |  |  |      |  F2                           |

   |  |  v      |                               |

   |  |  -------|-------------------------------|

   |  |         |                               |

   |  |         |  Saved registers.             |

   |  |         |  S6                           |

   |-regoffset  |   .                           |

   |  |         |   .                           |

   |  |         |  S0                           |

   |  |         |  pdr.pcreg                    |

   |  v         |                               |

   |  ----------|-------------------------------|

   |            |                               |

 frameoffset    |  Argument build area, gets    |

   |            |  7th ... nth arg for any      |

   |            |  called procedure.            |

   v            |                               |

   -------------|-------------------------------|<-- sp

                |                               |            */

#define PROC_LOW_ADDR(PROC) ((PROC)->pdr.adr)               /* least address */

#define PROC_HIGH_ADDR(PROC) ((PROC)->pdr.iline)      /* upper address bound */

#define PROC_DUMMY_FRAME(PROC) ((PROC)->pdr.cbLineOffset) /*CALL_DUMMY frame */

#define PROC_FRAME_OFFSET(PROC) ((PROC)->pdr.frameoffset)

#define PROC_FRAME_REG(PROC) ((PROC)->pdr.framereg)

#define PROC_REG_MASK(PROC) ((PROC)->pdr.regmask)

#define PROC_FREG_MASK(PROC) ((PROC)->pdr.fregmask)

#define PROC_REG_OFFSET(PROC) ((PROC)->pdr.regoffset)

#define PROC_FREG_OFFSET(PROC) ((PROC)->pdr.fregoffset)

#define PROC_PC_REG(PROC) ((PROC)->pdr.pcreg)

#define PROC_LOCALOFF(PROC) ((PROC)->pdr.localoff)

/* Local storage allocation/deallocation functions.  trace_alloc does

   a malloc, but also chains allocated blocks on trace_alloc_chain, so

   they may all be freed on exit from __gnat_backtrace. */

struct alloc_chain

{

  struct alloc_chain *next;

  double x[0];

};

struct alloc_chain *trace_alloc_chain;

static void *

trace_alloc (unsigned int n)

{

  struct alloc_chain * result = malloc (n + sizeof(struct alloc_chain));

  result->next = trace_alloc_chain;

  trace_alloc_chain = result;

  return (void*) result->x;

}

static void

free_trace_alloc (void)

{

  while (trace_alloc_chain != 0)

    {

      struct alloc_chain *old = trace_alloc_chain;

      trace_alloc_chain = trace_alloc_chain->next;

      free (old);

    }

}

/* Read value at ADDR into *DEST, returning 0 if this is valid, != 0

   otherwise. */

static int

read_memory_safe4 (CORE_ADDR addr, unsigned int *dest)

{

  *dest = *((unsigned int*) addr);

  return 0;

}

/* Read value at ADDR into *DEST, returning 0 if this is valid, != 0

   otherwise. */

static int

read_memory_safe8 (CORE_ADDR addr, CORE_ADDR *dest)

{

  *dest = *((CORE_ADDR*) addr);

  return 0;

}

static CORE_ADDR

read_register (int regno)

{

  if (regno >= 0 && regno < 31)

    return theRegisters[regno];

  return (CORE_ADDR) 0;

}

static void

frame_saved_regs_zalloc (struct frame_info *fi)

{

  fi->saved_regs = (CORE_ADDR *) trace_alloc (SIZEOF_FRAME_SAVED_REGS);

  memset (fi->saved_regs, 0, SIZEOF_FRAME_SAVED_REGS);

}

static void *

frame_obstack_alloc (unsigned long size)

{

  return (void *) trace_alloc (size);

}

static int

inside_entry_file (CORE_ADDR addr)

{

  if (addr == 0)

    return 1;

  else

    return 0;

}

static CORE_ADDR

alpha_saved_pc_after_call (struct frame_info *frame)

{

  CORE_ADDR pc = frame->pc;

  alpha_extra_func_info_t proc_desc;

  int pcreg;

  proc_desc = find_proc_desc (pc, frame->next, NULL);

  pcreg = proc_desc ? PROC_PC_REG (proc_desc) : RA_REGNUM;

  return read_register (pcreg);

}

/* Guaranteed to set frame->saved_regs to some values (it never leaves it

   NULL).  */

static void

alpha_find_saved_regs (struct frame_info *frame)

{

  int ireg;

  CORE_ADDR reg_position;

  unsigned long mask;

  alpha_extra_func_info_t proc_desc;

  int returnreg;

  frame_saved_regs_zalloc (frame);

  /* If it is the frame for __sigtramp, the saved registers are located in a

     sigcontext structure somewhere on the stack. __sigtramp passes a pointer

     to the sigcontext structure on the stack.  If the stack layout for

     __sigtramp changes, or if sigcontext offsets change, we might have to

     update this code.  */

#ifndef SIGFRAME_PC_OFF

#define SIGFRAME_PC_OFF         (2 * 8)

#define SIGFRAME_REGSAVE_OFF    (4 * 8)

#define SIGFRAME_FPREGSAVE_OFF  (SIGFRAME_REGSAVE_OFF + 32 * 8 + 8)

#endif

  proc_desc = frame->proc_desc;

  if (proc_desc == NULL)

    /* I'm not sure how/whether this can happen.  Normally when we can't

       find a proc_desc, we "synthesize" one using heuristic_proc_desc

       and set the saved_regs right away.  */

    return;

  /* Fill in the offsets for the registers which gen_mask says

     were saved.  */

  reg_position = frame->frame + PROC_REG_OFFSET (proc_desc);

  mask = PROC_REG_MASK (proc_desc);

  returnreg = PROC_PC_REG (proc_desc);

  /* Note that RA is always saved first, regardless of its actual

     register number.  */

  if (mask & (1 << returnreg))

    {

      frame->saved_regs[returnreg] = reg_position;

      reg_position += 8;

      mask &= ~(1 << returnreg);        /* Clear bit for RA so we

                                           don't save again later. */

    }

  for (ireg = 0; ireg <= 31; ireg++)

    if (mask & (1 << ireg))

      {

        frame->saved_regs[ireg] = reg_position;

        reg_position += 8;

      }

  /* Fill in the offsets for the registers which float_mask says

     were saved.  */

  reg_position = frame->frame + PROC_FREG_OFFSET (proc_desc);

  mask = PROC_FREG_MASK (proc_desc);

  for (ireg = 0; ireg <= 31; ireg++)

    if (mask & (1 << ireg))

      {

        frame->saved_regs[FP0_REGNUM + ireg] = reg_position;

        reg_position += 8;

      }

  frame->saved_regs[PC_REGNUM] = frame->saved_regs[returnreg];

}

static CORE_ADDR

read_next_frame_reg (struct frame_info *fi, int regno)

{

  CORE_ADDR result;

  for (; fi; fi = fi->next)

    {

      /* We have to get the saved sp from the sigcontext

         if it is a signal handler frame.  */

      if (regno == SP_REGNUM)

        return fi->frame;

      else

        {

          if (fi->saved_regs == 0)

            alpha_find_saved_regs (fi);

          if (fi->saved_regs[regno])

            {

              if (read_memory_safe8 (fi->saved_regs[regno], &result) == 0)

                return result;

              else

                return 0;

            }

        }

    }

  return read_register (regno);

}

static CORE_ADDR

alpha_frame_saved_pc (struct frame_info *frame)

{

  return read_next_frame_reg (frame, frame->pc_reg);

}

static struct alpha_extra_func_info temp_proc_desc;

/* Nonzero if instruction at PC is a return instruction.  "ret

   $zero,($ra),1" on alpha. */

static int

alpha_about_to_return (CORE_ADDR pc)

{

  int inst;

  read_memory_safe4 (pc, &inst);

  return inst == 0x6bfa8001;

}

/* A heuristically computed start address for the subprogram

   containing address PC.   Returns 0 if none detected. */

static CORE_ADDR

heuristic_proc_start (CORE_ADDR pc)

{

  CORE_ADDR start_pc = pc;

  CORE_ADDR fence = start_pc - heuristic_fence_post;

  if (start_pc == 0)

    return 0;

  if (heuristic_fence_post == UINT_MAX

      || fence < VM_MIN_ADDRESS)

    fence = VM_MIN_ADDRESS;

  /* search back for previous return */

  for (start_pc -= 4; ; start_pc -= 4)

    {

      if (start_pc < fence)

        return 0;

      else if (alpha_about_to_return (start_pc))

        break;

    }

  start_pc += 4;                /* skip return */

  return start_pc;

}

static alpha_extra_func_info_t

heuristic_proc_desc (CORE_ADDR start_pc,

                     CORE_ADDR limit_pc,

                     struct frame_info *next_frame,

                     struct frame_saved_regs *saved_regs_p)

{

  CORE_ADDR sp = read_next_frame_reg (next_frame, SP_REGNUM);

  CORE_ADDR cur_pc;

  int frame_size;

  int has_frame_reg = 0;

  unsigned long reg_mask = 0;

  int pcreg = -1;

  if (start_pc == 0)

    return 0;

  memset (&temp_proc_desc, '\0', sizeof (temp_proc_desc));

  if (saved_regs_p != 0)

    memset (saved_regs_p, '\0', sizeof (struct frame_saved_regs));

  PROC_LOW_ADDR (&temp_proc_desc) = start_pc;

  if (start_pc + 200 < limit_pc)

    limit_pc = start_pc + 200;

  frame_size = 0;

  for (cur_pc = start_pc; cur_pc < limit_pc; cur_pc += 4)

    {

      unsigned int word;

      int status;

      status = read_memory_safe4 (cur_pc, &word);

      if (status)

        return 0;

      if ((word & 0xffff0000) == 0x23de0000)    /* lda $sp,n($sp) */

        {

          if (word & 0x8000)

            frame_size += (-word) & 0xffff;

          else

            /* Exit loop if a positive stack adjustment is found, which

               usually means that the stack cleanup code in the function

               epilogue is reached.  */

            break;

        }

      else if ((word & 0xfc1f0000) == 0xb41e0000        /* stq reg,n($sp) */

               && (word & 0xffff0000) != 0xb7fe0000)    /* reg != $zero */

        {

          int reg = (word & 0x03e00000) >> 21;

          reg_mask |= 1 << reg;

          if (saved_regs_p != 0)

            saved_regs_p->regs[reg] = sp + (short) word;

          /* Starting with OSF/1-3.2C, the system libraries are shipped

             without local symbols, but they still contain procedure

             descriptors without a symbol reference. GDB is currently

             unable to find these procedure descriptors and uses

             heuristic_proc_desc instead.

             As some low level compiler support routines (__div*, __add*)

             use a non-standard return address register, we have to

             add some heuristics to determine the return address register,

             or stepping over these routines will fail.

             Usually the return address register is the first register

             saved on the stack, but assembler optimization might

             rearrange the register saves.

             So we recognize only a few registers (t7, t9, ra) within

             the procedure prologue as valid return address registers.

             If we encounter a return instruction, we extract the

             the return address register from it.

             FIXME: Rewriting GDB to access the procedure descriptors,

             e.g. via the minimal symbol table, might obviate this hack.  */

          if (pcreg == -1

              && cur_pc < (start_pc + 80)

              && (reg == T7_REGNUM || reg == T9_REGNUM || reg == RA_REGNUM))

            pcreg = reg;

        }

      else if ((word & 0xffe0ffff) == 0x6be08001)       /* ret zero,reg,1 */

        pcreg = (word >> 16) & 0x1f;

      else if (word == 0x47de040f)      /* bis sp,sp fp */

        has_frame_reg = 1;

    }

  if (pcreg == -1)

    {

      /* If we haven't found a valid return address register yet,

         keep searching in the procedure prologue.  */

      while (cur_pc < (limit_pc + 80) && cur_pc < (start_pc + 80))

        {

          unsigned int word;

          if (read_memory_safe4 (cur_pc, &word))

            break;

          cur_pc += 4;

          if ((word & 0xfc1f0000) == 0xb41e0000         /* stq reg,n($sp) */

              && (word & 0xffff0000) != 0xb7fe0000)     /* reg != $zero */

            {

              int reg = (word & 0x03e00000) >> 21;

              if (reg == T7_REGNUM || reg == T9_REGNUM || reg == RA_REGNUM)

                {

                  pcreg = reg;

                  break;

                }

            }

          else if ((word & 0xffe0ffff) == 0x6be08001)   /* ret zero,reg,1 */

            {

              pcreg = (word >> 16) & 0x1f;

              break;

            }

        }

    }

  if (has_frame_reg)

    PROC_FRAME_REG (&temp_proc_desc) = GCC_FP_REGNUM;

  else

    PROC_FRAME_REG (&temp_proc_desc) = SP_REGNUM;

  PROC_FRAME_OFFSET (&temp_proc_desc) = frame_size;

  PROC_REG_MASK (&temp_proc_desc) = reg_mask;

  PROC_PC_REG (&temp_proc_desc) = (pcreg == -1) ? RA_REGNUM : pcreg;

  PROC_LOCALOFF (&temp_proc_desc) = 0;   /* XXX - bogus */

  return &temp_proc_desc;

}

static alpha_extra_func_info_t

find_proc_desc (CORE_ADDR pc,

                struct frame_info *next_frame,

                struct frame_saved_regs *saved_regs)

{

  CORE_ADDR startaddr;

  /* If heuristic_fence_post is nonzero, determine the procedure

     start address by examining the instructions.

     This allows us to find the start address of static functions which

     have no symbolic information, as startaddr would have been set to

     the preceding global function start address by the

     find_pc_partial_function call above.  */

  startaddr = heuristic_proc_start (pc);

  return heuristic_proc_desc (startaddr, pc, next_frame, saved_regs);

}

static CORE_ADDR

alpha_frame_chain (struct frame_info *frame)

{

  alpha_extra_func_info_t proc_desc;

  CORE_ADDR saved_pc = FRAME_SAVED_PC (frame);

  if (saved_pc == 0 || inside_entry_file (saved_pc))

    return 0;

  proc_desc = find_proc_desc (saved_pc, frame, NULL);

  if (!proc_desc)

    return 0;

  /* If no frame pointer and frame size is zero, we must be at end

     of stack (or otherwise hosed).  If we don't check frame size,

     we loop forever if we see a zero size frame.  */

  if (PROC_FRAME_REG (proc_desc) == SP_REGNUM

      && PROC_FRAME_OFFSET (proc_desc) == 0)

    return 0;

  else

    return read_next_frame_reg (frame, PROC_FRAME_REG (proc_desc))

      + PROC_FRAME_OFFSET (proc_desc);

}

static void

init_extra_frame_info (struct frame_info *frame)

{

  struct frame_saved_regs temp_saved_regs;

  alpha_extra_func_info_t proc_desc =

    find_proc_desc (frame->pc, frame->next, &temp_saved_regs);

  frame->saved_regs = NULL;

  frame->localoff = 0;

  frame->pc_reg = RA_REGNUM;

  frame->proc_desc = proc_desc;

  if (proc_desc)

    {

      /* Get the locals offset and the saved pc register from the

         procedure descriptor, they are valid even if we are in the

         middle of the prologue.  */

      frame->localoff = PROC_LOCALOFF (proc_desc);

      frame->pc_reg = PROC_PC_REG (proc_desc);

      /* Fixup frame-pointer - only needed for top frame */

      /* This may not be quite right, if proc has a real frame register.

         Get the value of the frame relative sp, procedure might have been

         interrupted by a signal at it's very start.  */

      if (frame->pc == PROC_LOW_ADDR (proc_desc))

        frame->frame = read_next_frame_reg (frame->next, SP_REGNUM);

      else

        frame->frame

          = (read_next_frame_reg (frame->next, PROC_FRAME_REG (proc_desc))

             + PROC_FRAME_OFFSET (proc_desc));

      frame->saved_regs

        = (CORE_ADDR *) frame_obstack_alloc (SIZEOF_FRAME_SAVED_REGS);

      memcpy

        (frame->saved_regs, temp_saved_regs.regs, SIZEOF_FRAME_SAVED_REGS);

      frame->saved_regs[PC_REGNUM] = frame->saved_regs[RA_REGNUM];

    }

}

/* Create an arbitrary (i.e. address specified by user) or innermost frame.

   Always returns a non-NULL value.  */

static struct frame_info *

create_new_frame (CORE_ADDR addr, CORE_ADDR pc)

{

  struct frame_info *fi;

  fi = (struct frame_info *)

    trace_alloc (sizeof (struct frame_info));

  /* Arbitrary frame */

  fi->next = NULL;

  fi->prev = NULL;

  fi->frame = addr;

  fi->pc = pc;

#ifdef INIT_EXTRA_FRAME_INFO

  INIT_EXTRA_FRAME_INFO (0, fi);