ppc-macosx-tdep.c   [plain text]

/* Mac OS X support for GDB, the GNU debugger.
   Copyright 1997, 1998, 1999, 2000, 2001, 2002
   Free Software Foundation, Inc.

   Contributed by Apple Computer, Inc.

   This file is part of GDB.

   This program 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 of the License, or
   (at your option) any later version.

   This program 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 this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#include "ppc-macosx-regs.h"
#include "ppc-macosx-tdep.h"
#include "ppc-macosx-frameinfo.h"
#include "ppc-macosx-frameops.h"

#include "defs.h"
#include "frame.h"
#include "inferior.h"
#include "symtab.h"
#include "target.h"
#include "gdbcore.h"
#include "symfile.h"
#include "objfiles.h"
#include "gdbcmd.h"
#include "arch-utils.h"
#include "floatformat.h"
#include "gdbtypes.h"
#include "regcache.h"

#include "libbfd.h"

#include "elf-bfd.h"
#include "dis-asm.h"

#undef XMALLOC
#define XMALLOC(TYPE) ((TYPE*) xmalloc (sizeof (TYPE)))

struct gdbarch_tdep
{
};

static int ppc_debugflag = 0;
static unsigned int ppc_max_frame_size = UINT_MAX;

void ppc_debug (const char *fmt, ...)
{
  va_list ap;
  if (ppc_debugflag) {
    va_start (ap, fmt);
    vfprintf (stderr, fmt, ap);
    va_end (ap);
  }
}

/* Default offset from SP where the LR is stored */

#define	DEFAULT_LR_SAVE 8

/* function implementations */

void
ppc_init_extra_frame_info (fromleaf, frame)
     int fromleaf;
     struct frame_info *frame;
{
  CHECK_FATAL (frame != NULL);

  frame->extra_info = (struct frame_extra_info *)
    frame_obstack_alloc (sizeof (struct frame_extra_info));

  frame->extra_info->initial_sp = 0;
  frame->extra_info->bounds = NULL;
  frame->extra_info->props = 0;
  frame->signal_handler_caller = 0;
}

void
ppc_print_extra_frame_info (frame)
     struct frame_info *frame;
{
  if (frame->signal_handler_caller) {
    printf_filtered (" This function was called from a signal handler.\n");
  } else {
    printf_filtered (" This function was not called from a signal handler.\n");
  }

  ppc_frame_cache_initial_stack_address (frame);
  if (frame->extra_info->initial_sp) {
    printf_filtered (" The initial stack pointer for this frame was 0x%lx.\n", 
		     (unsigned long) frame->extra_info->initial_sp);
  } else {
    printf_filtered (" Unable to determine initial stack pointer for this frame.\n");
  }    

  ppc_frame_cache_boundaries (frame, NULL);
  if (frame->extra_info->bounds != NULL) {
    ppc_print_boundaries (frame->extra_info->bounds);
  } else {
    printf_filtered (" Unable to determine function boundary information.\n");
  }

  ppc_frame_cache_properties (frame, NULL);
  if (frame->extra_info->props != NULL) {
    ppc_print_properties (frame->extra_info->props);
  } else {
    printf_filtered (" Unable to determine function property information.\n");
  }
}
/* We need to make sure that ppc_init_frame_pc_first won't longjmp, 
   since if it does it can leave a frame structure with no extra_info
   allocated in get_prev_frame, and there are way too many places that
   assume that a valid frame has a valid extra_info to catch them all. */

struct ppc_init_frame_pc_args
{
  int fromleaf;
  struct frame_info *frame;
};

int
ppc_init_frame_pc_first_unsafe (struct ppc_init_frame_pc_args *args)
{
  struct frame_info *frame = args->frame;
  struct frame_info *next;

  CHECK_FATAL (frame != NULL);
  next = get_next_frame (frame);
  CHECK_FATAL (next != NULL);
  frame->pc = ppc_frame_saved_pc (next);

  return 1;
}

void
ppc_init_frame_pc_first (int fromleaf, struct frame_info *frame)
{
  struct ppc_init_frame_pc_args args;

  args.fromleaf = fromleaf;
  args.frame = frame;

  if (!catch_errors ((catch_errors_ftype *) ppc_init_frame_pc_first_unsafe, 
		     &args, "", RETURN_MASK_ERROR))
    {
      ppc_debug ("ppc_init_frame_pc_first: got an error calling %s.\n", 
		 "ppc_frame_saved_pc.\n");
    }
}

void
ppc_init_frame_pc (fromleaf, frame)
     int fromleaf;
     struct frame_info *frame;
{
  CHECK_FATAL (frame != NULL);
}

/* ppc_get_unsaved_pc 
   
   This function hides a little complication when you are looking for
   a the saved pc in a frame which either does not save the pc, or saves
   it but hasn't done so yet.  In that case, the pc may still be in the
   link register, but it ALSO might have gotten displaced by the PIC base
   setting call - which does "blc pc+4; mflr r31" so the lr is wrong for
   a little while.
*/

CORE_ADDR
ppc_get_unsaved_pc (struct frame_info *frame, ppc_function_properties *props)
{
  struct frame_info *cur_frame;
  CORE_ADDR retval;
  
  if ((props->lr_reg == -1)
      || ((props->lr_invalid == 0) 
	  || (frame->pc <= props->lr_invalid)
	  || (frame->pc > props->lr_valid_again)))
    {
      ppc_debug ("ppc_get_unsaved_pc: link register was not saved.\n");
      cur_frame = get_current_frame ();
      set_current_frame (frame);
      retval = read_register (LR_REGNUM);
      set_current_frame (cur_frame);
    }
  else
    {
      ppc_debug ("ppc_get_unsaved_pc: link register stashed in register %d.\n",
		 props->lr_reg);
      cur_frame = get_current_frame ();
      set_current_frame (frame);
      retval = read_register (props->lr_reg);
      set_current_frame (cur_frame);
    }
  return retval;
}

CORE_ADDR
ppc_frame_find_pc (frame)
     struct frame_info *frame;
{
  CORE_ADDR prev;

  CHECK_FATAL (frame != NULL);

  if (frame->signal_handler_caller) {
    CORE_ADDR psp = read_memory_unsigned_integer (frame->frame, 4);
    CORE_ADDR retval;
    /* psp is the top of the signal handler data pushed by the kernel */
    /* 0x220 is offset to SIGCONTEXT; 0x10 is offset to $pc */
    ppc_debug ("ppc_frame_saved_pc: determing previous pc from signal context\n");

    retval = read_memory_unsigned_integer (psp + 0x70, 4);
    ppc_debug ("Signal frame at: 0x%lx, saved pc at: 0x%lx.\n", psp, retval);
    return retval;
  }

  prev = ppc_frame_chain (frame);
  if ((prev == 0) || (! ppc_frame_chain_valid (prev, frame))) { 
    ppc_debug ("ppc_frame_find_pc: previous stack frame not valid: returning 0\n");
    return 0; 
  }
  ppc_debug ("ppc_frame_find_pc: value of prev is 0x%lx\n", (unsigned long) prev);

  if (ppc_frame_cache_properties (frame, NULL) != 0) 
    {
      ppc_debug ("ppc_frame_find_pc: unable to find properties of function containing 0x%lx\n",
		 (unsigned long) frame->pc);
      ppc_debug ("ppc_frame_find_pc: assuming link register saved in normal location\n");
      
      if (ppc_frameless_function_invocation (frame)) 
	{
	  /* FIXME: Formally, we ought to check for frameless function
	     invocation, but in fact, ppc_frameless_function_invocation
	     first calls ppc_frame_cache_properties and returns 0 if it
	     fails.  Since this just failed above, we won't ever get
	     into this branch. But I don't know another way to figure
	     this out. */
	  return read_register (LR_REGNUM);
	} 
      else 
	{
	  ppc_function_properties lprops;
	  CORE_ADDR body_start;
	  body_start = ppc_parse_instructions (frame->pc, INVALID_ADDRESS, 
					       &lprops);
          
	  /* We get here if we are a bit lost: after all we weren't
	     able to successfully run ppc_frame_cache_properties.  So
	     we should treat the lprops with some caution.  One common
	     mistake is to falsly assume the lr hasn't been saved
	     (since un-interpretible prologue and frameless prologue
	     look kind of the same).  So add this obvious check
	     here for being a leaf fn. in the first branch... */
	  
	  if ((frame->next == NULL && lprops.lr_saved == 0) || 
	      (lprops.lr_saved >= frame->pc))
	    {
      	      /* Either we aren't saving the link register, or our scan
		 shows that the link register WILL be saved, but has not
		 been yet.  So figure out where it actually is.  To do this,
		 we need to see if the lr is ever stomped, and if so, if we
		 are within that part of the prologue.
	      */
	      return ppc_get_unsaved_pc (frame, &lprops);
	    }
	  else
	    {
	      /* The link register is safely on the stack... */
	      return read_memory_unsigned_integer (prev + DEFAULT_LR_SAVE, 4);
	    }
	}
    }
  else
    {
      ppc_function_properties *props;

      props = frame->extra_info->props;
      CHECK_FATAL (props != NULL);

      if (props->lr_saved)
	{
	  if (props->lr_saved < frame->pc)
	    {
	      /* The link register is safely on the stack... */
	      return read_memory_unsigned_integer (prev 
						   + props->lr_offset, 4);
	    }
	  else 
	    {
	      ppc_debug ("ppc_frame_find_pc: function did not save link register\n");
	      return ppc_get_unsaved_pc (frame, props);
	    }
        }
      else if (frame->next && frame->next->signal_handler_caller) 
	{
	  ppc_debug ("ppc_frame_find_pc: %s\n", 
		     "using link area from signal handler.");
	  return read_memory_unsigned_integer (frame->frame - 0x320 
					       + DEFAULT_LR_SAVE, 4);
	}
      else if (frame->next && ppc_is_dummy_frame (frame->next)) 
	{
	  ppc_debug ("ppc_frame_find_pc: using link area from call dummy\n");
	  return read_memory_unsigned_integer (frame->frame - 0x1c, 4);
	}
      else if (!props->lr_saved)
	{
	  return ppc_get_unsaved_pc (frame, props);
	}
      else
	{
	  ppc_debug ("ppc_frame_find_pc: function is not a leaf\n");
	  ppc_debug ("ppc_frame_find_pc: assuming link register saved in normal location\n");
	  return read_memory_unsigned_integer (prev + DEFAULT_LR_SAVE, 4);
	}
    }
  /* Should never get here, just quiets the compiler. */
  return 0;
}

CORE_ADDR
ppc_frame_saved_pc (frame)
     struct frame_info *frame;
{
  return (ppc_frame_find_pc (frame));
}


CORE_ADDR
ppc_frame_saved_pc_after_call (frame)
     struct frame_info *frame;
{
  CHECK_FATAL (frame != NULL);
  return read_register (LR_REGNUM);
}

CORE_ADDR
ppc_frame_chain (frame)
     struct frame_info *frame;
{
  CORE_ADDR psp = read_memory_unsigned_integer (frame->frame, 4);

  if (frame->signal_handler_caller) {
    /* psp is the top of the signal handler data pushed by the kernel */
    /* 0x70 is offset to PPC_SAVED_STATE; 0xc is offset to $r1 */
    return read_memory_unsigned_integer (psp + 0x70 + 0xc, 4);
  }

  /* If a frameless function is interrupted by a signal, no change to
     the stack pointer */
  if (frame->next != NULL
      && frame->next->signal_handler_caller
      && ppc_frameless_function_invocation (frame)) {
    return frame->frame;
  }

  return psp;
}

int 
ppc_frame_chain_valid (chain, frame)
     CORE_ADDR chain;
     struct frame_info *frame;
{
  unsigned long retval;

  if (chain == 0) { return 0; }

  /* reached end of stack? */
  if (!safe_read_memory_unsigned_integer (chain, 4, &retval))
    {
        ppc_debug ("ppc_frame_chain_valid: Got an error reading at 0x%lx",
                   chain);
        return 0;
    }
  else
    if (retval == 0) { return 0; }

#if 0
  if (inside_entry_func (frame->pc)) { return 0; }
  if (inside_main_func (frame->pc)) { return 0; }
#endif

  /* check for bogus stack frames */
  if (! (chain >= frame->frame)) {
    warning ("ppc_frame_chain_valid: stack pointer from 0x%lx to 0x%lx "
	     "grows upward; assuming invalid\n",
	     (unsigned long) frame->frame, (unsigned long) chain);
    return 0;
  }
  if ((chain - frame->frame) > ppc_max_frame_size) {
    warning ("ppc_frame_chain_valid: stack frame from 0x%lx to 0x%lx "
	     "larger than ppc-maximum-frame-size bytes; assuming invalid",
	     (unsigned long) frame->frame, (unsigned long) chain);
    return 0;
  }

  return 1;
}

int
ppc_is_dummy_frame (frame)
     struct frame_info *frame;
{
  /* using get_prev_frame or ppc_frame_chain 
     would cause infinite recursion in some cases */

  CORE_ADDR chain = read_memory_unsigned_integer (frame->frame, 4);

  if (frame->signal_handler_caller) {
    /* psp is the top of the signal handler data pushed by the kernel */
    /* 0x70 is offset to PPC_SAVED_STATE; 0xc is offset to $r1 */
    chain = read_memory_unsigned_integer (chain + 0x70 + 0xc, 4);
  }
    
  if (chain == 0) { return 0; }
  return (PC_IN_CALL_DUMMY (frame->pc, frame->frame, chain));
}

/* Return the address of a frame. This is the inital %sp value when the frame
   was first allocated. For functions calling alloca(), it might be saved in
   the frame pointer register. */

CORE_ADDR
ppc_frame_cache_initial_stack_address (frame)
     struct frame_info *frame;
{
  CHECK_FATAL (frame != NULL);
  CHECK_FATAL (frame->extra_info != NULL);
    
  if (frame->extra_info->initial_sp == 0) { 
    frame->extra_info->initial_sp = ppc_frame_initial_stack_address (frame);
  }
  return frame->extra_info->initial_sp;
}

CORE_ADDR
ppc_frame_initial_stack_address (frame)
     struct frame_info *frame;
{
  CORE_ADDR tmpaddr;
  struct frame_info *callee;

  /* Find out if this function is using an alloca register. */

  if (ppc_frame_cache_properties (frame, NULL) != 0) {
    ppc_debug ("ppc_frame_initial_stack_address: unable to find properties of " 
		 "function containing 0x%lx\n", frame->pc);
    return 0;
  }

  /* Read and cache saved registers if necessary. */

  ppc_frame_cache_saved_regs (frame);

  /* If no alloca register is used, then frame->frame is the value of
     %sp for this frame, and it is valid. */

  if (frame->extra_info->props->frameptr_reg < 0) {
    frame->extra_info->initial_sp = frame->frame;
    return frame->extra_info->initial_sp;
  }

  /* This function has an alloca register. If this is the top-most frame
     (with the lowest address), the value in alloca register is valid. */

  if (! get_next_frame (frame)) 
    {
      frame->extra_info->initial_sp 
	= read_register (frame->extra_info->props->frameptr_reg);     
      return frame->extra_info->initial_sp;
    }

  /* Otherwise, this is a caller frame. Callee has usually already saved
     registers, but there are exceptions (such as when the callee
     has no parameters). Find the address in which caller's alloca
     register is saved. */

  for (callee = get_next_frame (frame); callee != NULL; 
       callee = get_next_frame (callee)) 
    {

      ppc_frame_cache_saved_regs (callee);
      
      /* this is the address in which alloca register is saved. */
      
      tmpaddr = callee->saved_regs[frame->extra_info->props->frameptr_reg];
      if (tmpaddr) {
	frame->extra_info->initial_sp 
	  = read_memory_unsigned_integer (tmpaddr, 4); 
	return frame->extra_info->initial_sp;
      }

      /* Go look into deeper levels of the frame chain to see if any one of
	 the callees has saved the frame pointer register. */
    }

  /* If frame pointer register was not saved, by the callee (or any of
     its callees) then the value in the register is still good. */

  frame->extra_info->initial_sp 
    = read_register (frame->extra_info->props->frameptr_reg);     
  return frame->extra_info->initial_sp;
}

int
ppc_is_magic_function_pointer (addr)
     CORE_ADDR addr;
{
  return 0;
}

/* Usually a function pointer's representation is simply the address of
   the function. On the RS/6000 however, a function pointer is represented
   by a pointer to a TOC entry. This TOC entry contains three words,
   the first word is the address of the function, the second word is the
   TOC pointer (r2), and the third word is the static chain value.
   Throughout GDB it is currently assumed that a function pointer contains
   the address of the function, which is not easy to fix.
   In addition, the conversion of a function address to a function
   pointer would require allocation of a TOC entry in the inferior's
   memory space, with all its drawbacks.
   To be able to call C++ virtual methods in the inferior (which are called
   via function pointers), find_function_addr uses this macro to
   get the function address from a function pointer.  */

CORE_ADDR
ppc_convert_from_func_ptr_addr (addr)
     CORE_ADDR addr;
{
  return (ppc_is_magic_function_pointer (addr) ? read_memory_unsigned_integer (addr, 4) : (addr));
}

CORE_ADDR
ppc_find_toc_address (pc)
     CORE_ADDR pc;
{
  return 0;
}

int ppc_use_struct_convention (gccp, valtype)
     int gccp;
     struct type *valtype;
{
  return 1;
}

CORE_ADDR
ppc_extract_struct_value_address (regbuf)
  char regbuf[REGISTER_BYTES];
{
  return extract_unsigned_integer (&regbuf[REGISTER_BYTE (GP0_REGNUM + 3)], 4);
}

void
ppc_extract_return_value (valtype, regbuf, valbuf)
     struct type *valtype;
     char regbuf[REGISTER_BYTES];
     char *valbuf;
{
  int offset = 0;

  if (TYPE_CODE (valtype) == TYPE_CODE_FLT) {

    /* floats and doubles are returned in fpr1. fpr's have a size of 8 bytes.
       We need to truncate the return value into float size (4 byte) if
       necessary. */

    double dd;
    float ff;

    switch (TYPE_LENGTH (valtype)) {
    case 8: /* double */
      memcpy (valbuf, &regbuf[REGISTER_BYTE (FP0_REGNUM + 1)], 8);
      break;
    case 4:
      memcpy (&dd, &regbuf[REGISTER_BYTE (FP0_REGNUM + 1)], 8);
      ff = (float) dd;
      memcpy (valbuf, &ff, sizeof (float));
      break;
    default:
      error ("unknown TYPE_LENGTH for return type %d", TYPE_LENGTH (valtype));
    }

  } else {

    unsigned int gpretreg = GP0_REGNUM + 3;
    /* return value is copied starting from r3. */
    if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG
	&& TYPE_LENGTH (valtype) < REGISTER_RAW_SIZE (gpretreg))
      offset = REGISTER_RAW_SIZE (gpretreg) - TYPE_LENGTH (valtype);
    
    memcpy (valbuf, regbuf + REGISTER_BYTE (gpretreg) + offset,
	    TYPE_LENGTH (valtype));
  }
}

CORE_ADDR 
ppc_skip_prologue (pc)
     CORE_ADDR pc;
{
  ppc_function_boundaries_request request;
  ppc_function_boundaries bounds;
  int ret;
  
  ppc_clear_function_boundaries_request (&request);
  ppc_clear_function_boundaries (&bounds);

  request.prologue_start = pc;
  ret = ppc_find_function_boundaries (&request, &bounds);
  if (ret != 0) { return 0; }

  return bounds.body_start;
}

/* Determines whether the current frame has allocated a frame on the
   stack or not.  */

int
ppc_frameless_function_invocation (frame)
     struct frame_info *frame;
{
  /* if not a leaf, it's not frameless (unless it was interrupted by a
     signal or a call_dummy) */

  if (frame->next != NULL 
      && !frame->next->signal_handler_caller
      && !ppc_is_dummy_frame (frame->next))
    { 
      return 0; 
    }

  if (ppc_frame_cache_properties (frame, NULL) != 0) {
    ppc_debug ("frameless_function_invocation: unable to find properties of " 
		 "function containing 0x%lx; assuming not frameless\n", 
	       frame->pc);
    return 0;
  }


  return frame->extra_info->props->frameless;
}

char *gdb_register_names[] =
{
  "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
  "r8", "r9", "r10","r11","r12","r13","r14","r15",
  "r16","r17","r18","r19","r20","r21","r22","r23",
  "r24","r25","r26","r27","r28","r29","r30","r31",
  "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7",
  "f8", "f9", "f10","f11","f12","f13","f14","f15",
  "f16","f17","f18","f19","f20","f21","f22","f23",
  "f24","f25","f26","f27","f28","f29","f30","f31",
  "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7",
  "v8", "v9", "v10","v11","v12","v13","v14","v15",
  "v16","v17","v18","v19","v20","v21","v22","v23",
  "v24","v25","v26","v27","v28","v29","v30","v31",
  "pc", "ps", "cr", "lr", "ctr", "xer", "mq",
  "fpscr",
  "vscr", "vrsave"
};

char *
ppc_register_name (int reg_nr)
{
  if (reg_nr < 0)
    return NULL;
  if (reg_nr >= (sizeof (gdb_register_names) / sizeof (*gdb_register_names)))
    return NULL;
  return gdb_register_names[reg_nr];
}

void ppc_store_struct_return (CORE_ADDR addr, CORE_ADDR sp)
{
  write_register (SRA_REGNUM, addr);
}

void ppc_store_return_value (struct type *type, char *valbuf)
{
  /* Floating point values are returned starting from FPR1 and up.
     Say a double_double_double type could be returned in
     FPR1/FPR2/FPR3 triple. */

  if (TYPE_CODE (type) == TYPE_CODE_FLT)
    write_register_bytes (REGISTER_BYTE (FPRV_REGNUM), (valbuf), TYPE_LENGTH (type));
  else
    write_register_bytes (REGISTER_BYTE (RV_REGNUM), (valbuf), TYPE_LENGTH (type));	 
}

CORE_ADDR ppc_push_return_address (CORE_ADDR pc, CORE_ADDR sp)
{
  return sp;
}

/* Nonzero if register N requires conversion
   from raw format to virtual format.
   The register format for rs6000 floating point registers is always
   double, we need a conversion if the memory format is float.  */

int ppc_register_convertible (int regno)
{
  return ((regno >= FIRST_FP_REGNUM) && (regno <= LAST_FP_REGNUM));
}

/* Convert data from raw format for register REGNUM in buffer FROM
   to virtual format with type TYPE in buffer TO.  */

void ppc_register_convert_to_virtual
(int regno, struct type *type, char *from, char *to)
{ 
  if (TYPE_LENGTH (type) != REGISTER_RAW_SIZE (regno)) 
    { 
      double val = extract_floating (from, REGISTER_RAW_SIZE (regno)); 
      store_floating (to, TYPE_LENGTH (type), val); 
    } 
  else 
    memcpy (to, from, REGISTER_RAW_SIZE (regno)); 
}

/* Convert data from virtual format with type TYPE in buffer FROM
   to raw format for register REGNUM in buffer TO.  */

void ppc_register_convert_to_raw
(struct type *type, int regno, char *from, char *to)
{ 
  if (TYPE_LENGTH (type) != REGISTER_RAW_SIZE (regno)) 
    { 
      double val = extract_floating (from, TYPE_LENGTH (type)); 
      store_floating (to, REGISTER_RAW_SIZE (regno), val); 
    } 
  else 
    memcpy (to, from, REGISTER_RAW_SIZE (regno)); 
}

/* Sequence of bytes for breakpoint instruction.  */

#define BIG_BREAKPOINT { 0x7f, 0xe0, 0x00, 0x08 }
#define LITTLE_BREAKPOINT { 0x08, 0x00, 0xe0, 0x7f }

static unsigned char *
ppc_breakpoint_from_pc (CORE_ADDR *addr, int *size)
{
  static unsigned char big_breakpoint[] = BIG_BREAKPOINT;
  static unsigned char little_breakpoint[] = LITTLE_BREAKPOINT;
  *size = 4;
  if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG)
    return big_breakpoint;
  else
    return little_breakpoint;
}

static int
ppc_register_byte (int N)
{
return (((N) >= FIRST_SP_REGNUM) ? ((((N) - FIRST_SP_REGNUM) * 4) + SIZE_GP_REGS + SIZE_FP_REGS + SIZE_VP_REGS) \
	: (((N) >= FIRST_VP_REGNUM) ? ((((N) - FIRST_VP_REGNUM) * 16) + SIZE_GP_REGS + SIZE_FP_REGS) \
	   : (((N) >= FIRST_FP_REGNUM) ? ((((N) - FIRST_FP_REGNUM) * 8) + SIZE_GP_REGS) \
	      : ((N) * 4))));
}

static int
ppc_register_raw_size (int N)
{
  return (((N) >= FIRST_SP_REGNUM) ? 4 
	  : (((N) >= FIRST_VP_REGNUM) ? 16 
	     : (((N) >= FIRST_FP_REGNUM) ? 8
		: 4)));
}

static int
ppc_register_virtual_size (int N)
{
  return (((N) >= FIRST_SP_REGNUM) ? 4
	  : (((N) >= FIRST_VP_REGNUM) ? 16
	     : (((N) >= FIRST_FP_REGNUM) ? 8
		: 4)));
}

static struct type *
ppc_register_virtual_type (int N)
{
  return (((N) >= FIRST_SP_REGNUM) ? builtin_type_unsigned_int
	  : (((N) >= FIRST_VP_REGNUM) ? builtin_type_vec128
	     : (((N) >= FIRST_FP_REGNUM) ? builtin_type_double
		: builtin_type_unsigned_int)));
}

static unsigned LONGEST ppc_call_dummy_words[]= 
{ 
  0xfeedfeed, 0xfeedfeed, 0xfeedfeed, 0xfeedfeed, 
  0xfeedfeed, 0xfeedfeed, 0xfeedfeed, 0xfeedfeed, 
  0xfeedfeed, 0xfeedfeed, 0xfeedfeed, 0xfeedfeed, 
  0xfeedfeed, 0xfeedfeed, 0xfeedfeed, 0xfeedfeed, 
  0xfeedfeed, 0xfeedfeed, 0xfeedfeed, 0xfeedfeed, 
  0xfeedfeed, 0xfeedfeed, 0xfeedfeed, 0xfeedfeed, 
  0xfeedfeed, 0xfeedfeed, 0xfeedfeed, 0xfeedfeed, 
  0xfeedfeed, 0xfeedfeed, 0xfeedfeed, 0xfeedfeed, 
  
  0x7c0802a6, /* mflr   r0             */ 
  0xd8010000, /* stfd   r?, num(r1)    */ 
  0xbc010000, /* stm    r0, num(r1)    */ 
  0x94210000, /* stwu   r1, num(r1)    */ 
  0xfeedfeed, 
  0xfeedfeed, 
  /* save toc pointer */ 
  0x3c400000, /* addis  r2, 0, 0x0     */ 
  0x60420000, /* ori    r2, r2, 0x0    */ 
  /* save function pointer */ 
  0x3d800000, /* lis    r12, 0x0       */ 
  0x618c0000, /* ori    r12, r12, 0x0  */ 
  /* call function */ 
  0x7d8903a6, /* mtctr r12              */ 
  0x4e800421, /* bctrl                 */ 
  /* breakpoint for function return */ 
  0x7fe00008, /* trap                  */ 
  0x60000000, /* nop                   */ 
  0xfeedfeed, 
  0xfeedfeed, 
  
  0xfeedfeed, 0xfeedfeed, 0xfeedfeed, 0xfeedfeed, 
  0xfeedfeed, 0xfeedfeed, 0xfeedfeed, 0xfeedfeed, 
  0xfeedfeed, 0xfeedfeed, 0xfeedfeed, 0xfeedfeed, 
  0xfeedfeed, 0xfeedfeed, 0xfeedfeed, 0xfeedfeed, 
  0xfeedfeed, 0xfeedfeed, 0xfeedfeed, 0xfeedfeed, 
  0xfeedfeed, 0xfeedfeed, 0xfeedfeed, 0xfeedfeed, 
  0xfeedfeed, 0xfeedfeed, 0xfeedfeed, 0xfeedfeed, 
  0xfeedfeed, 0xfeedfeed, 0xfeedfeed, 0xfeedfeed 
};

/* keep this as multiple of 16 ($sp requires 16 byte alignment) */

#define INSTRUCTION_SIZE 4

static struct gdbarch *
ppc_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
{
  struct gdbarch *gdbarch;
  struct gdbarch_tdep *tdep;

  arches = gdbarch_list_lookup_by_info (arches, &info);
  if (arches != NULL)
    return arches->gdbarch;

  tdep = XMALLOC (struct gdbarch_tdep);
  gdbarch = gdbarch_alloc (&info, tdep);

  set_gdbarch_read_pc (gdbarch, generic_target_read_pc);
  set_gdbarch_write_pc (gdbarch, generic_target_write_pc);
  set_gdbarch_read_fp (gdbarch, generic_target_read_fp);
  set_gdbarch_read_sp (gdbarch, generic_target_read_sp);
  set_gdbarch_write_sp (gdbarch, generic_target_write_sp);

  set_gdbarch_num_regs (gdbarch, NUM_REGS);
  set_gdbarch_sp_regnum (gdbarch, SP_REGNUM);
  set_gdbarch_fp_regnum (gdbarch, FP_REGNUM);
  set_gdbarch_pc_regnum (gdbarch, PC_REGNUM);
  set_gdbarch_stab_reg_to_regnum (gdbarch, ppc_macosx_stab_reg_to_regnum);

  set_gdbarch_register_name (gdbarch, ppc_register_name);
  set_gdbarch_register_size (gdbarch, 4);
  set_gdbarch_register_bytes (gdbarch, REGISTER_BYTES);
  set_gdbarch_register_byte (gdbarch, ppc_register_byte);
  set_gdbarch_register_raw_size (gdbarch, ppc_register_raw_size);
  set_gdbarch_max_register_raw_size (gdbarch, 16);
  set_gdbarch_register_virtual_size (gdbarch, ppc_register_virtual_size);
  set_gdbarch_max_register_virtual_size (gdbarch, 16);
  set_gdbarch_register_virtual_type (gdbarch, ppc_register_virtual_type);

  set_gdbarch_ptr_bit (gdbarch, 4 * TARGET_CHAR_BIT);
  set_gdbarch_short_bit (gdbarch, 2 * TARGET_CHAR_BIT);
  set_gdbarch_int_bit (gdbarch, 4 * TARGET_CHAR_BIT);
  set_gdbarch_long_bit (gdbarch, 4 * TARGET_CHAR_BIT);
  set_gdbarch_long_long_bit (gdbarch, 8 * TARGET_CHAR_BIT);
  set_gdbarch_float_bit (gdbarch, 4 * TARGET_CHAR_BIT);
  set_gdbarch_double_bit (gdbarch, 8 * TARGET_CHAR_BIT);
  set_gdbarch_long_double_bit (gdbarch, 8 * TARGET_CHAR_BIT);
  set_gdbarch_addr_bit (gdbarch, 4 * TARGET_CHAR_BIT);

  switch (info.byte_order)
    {
    case BFD_ENDIAN_BIG:
      set_gdbarch_float_format (gdbarch, &floatformat_ieee_single_big);
      set_gdbarch_double_format (gdbarch, &floatformat_ieee_double_big);
      set_gdbarch_long_double_format (gdbarch, &floatformat_ieee_double_big);
      break;
    case BFD_ENDIAN_LITTLE:
      set_gdbarch_float_format (gdbarch, &floatformat_ieee_single_little);
      set_gdbarch_double_format (gdbarch, &floatformat_ieee_double_little);
      set_gdbarch_long_double_format (gdbarch, &floatformat_ieee_double_little);
      break;
    default:
      internal_error (__FILE__, __LINE__, "ppc_gdbarch_init: bad byte order for float format");
    }

  set_gdbarch_call_dummy_words (gdbarch, ppc_call_dummy_words);
  set_gdbarch_sizeof_call_dummy_words (gdbarch, sizeof (ppc_call_dummy_words));
  set_gdbarch_use_generic_dummy_frames (gdbarch, 0);
  set_gdbarch_call_dummy_length (gdbarch, (32 + 16 + 32) * INSTRUCTION_SIZE);
  set_gdbarch_call_dummy_location (gdbarch, ON_STACK);
  set_gdbarch_call_dummy_address (gdbarch, 0);
  set_gdbarch_call_dummy_start_offset (gdbarch, (32 + 6) * INSTRUCTION_SIZE);
  set_gdbarch_call_dummy_breakpoint_offset_p (gdbarch, 1);
  set_gdbarch_call_dummy_breakpoint_offset (gdbarch, (32 + 6 + 6) * INSTRUCTION_SIZE);
  set_gdbarch_pc_in_call_dummy (gdbarch, pc_in_call_dummy_on_stack);
  set_gdbarch_call_dummy_p (gdbarch, 1);
  set_gdbarch_call_dummy_stack_adjust_p (gdbarch, 0);
  set_gdbarch_get_saved_register (gdbarch, generic_get_saved_register);
  set_gdbarch_fix_call_dummy (gdbarch, ppc_fix_call_dummy);
  set_gdbarch_push_dummy_frame (gdbarch, ppc_push_dummy_frame);

  set_gdbarch_push_return_address (gdbarch, ppc_push_return_address);
  set_gdbarch_believe_pcc_promotion (gdbarch, 1);
  set_gdbarch_coerce_float_to_double (gdbarch, standard_coerce_float_to_double);

  set_gdbarch_register_convertible (gdbarch, ppc_register_convertible);
  set_gdbarch_register_convert_to_virtual (gdbarch, ppc_register_convert_to_virtual);
  set_gdbarch_register_convert_to_raw (gdbarch, ppc_register_convert_to_raw);

  set_gdbarch_extract_return_value (gdbarch, ppc_extract_return_value);
  
  set_gdbarch_push_arguments (gdbarch, ppc_push_arguments);

  set_gdbarch_store_struct_return (gdbarch, ppc_store_struct_return);
  set_gdbarch_store_return_value (gdbarch, ppc_store_return_value);
  set_gdbarch_extract_struct_value_address (gdbarch, ppc_extract_struct_value_address);
  set_gdbarch_use_struct_convention (gdbarch, ppc_use_struct_convention);
  set_gdbarch_pop_frame (gdbarch, ppc_pop_frame);

  set_gdbarch_skip_prologue (gdbarch, ppc_skip_prologue);
  set_gdbarch_inner_than (gdbarch, core_addr_lessthan);
  set_gdbarch_decr_pc_after_break (gdbarch, 0);
  set_gdbarch_function_start_offset (gdbarch, 0);
  set_gdbarch_breakpoint_from_pc (gdbarch, ppc_breakpoint_from_pc);

  set_gdbarch_frame_args_skip (gdbarch, 0);

  set_gdbarch_frame_chain_valid (gdbarch, ppc_frame_chain_valid);
  set_gdbarch_frameless_function_invocation (gdbarch, ppc_frameless_function_invocation);
  set_gdbarch_frame_chain (gdbarch, ppc_frame_chain);
  set_gdbarch_frame_saved_pc (gdbarch, ppc_frame_saved_pc);
  set_gdbarch_frame_init_saved_regs (gdbarch, ppc_frame_cache_saved_regs);
  set_gdbarch_init_extra_frame_info (gdbarch, ppc_init_extra_frame_info);
  set_gdbarch_frame_args_address (gdbarch, ppc_frame_cache_initial_stack_address);
  set_gdbarch_frame_locals_address (gdbarch, ppc_frame_cache_initial_stack_address);
  set_gdbarch_saved_pc_after_call (gdbarch, ppc_frame_saved_pc_after_call);

  set_gdbarch_frame_num_args (gdbarch, frame_num_args_unknown);

  return gdbarch;
}

void
ppc_print_count_info (int frame, CORE_ADDR fp, CORE_ADDR pc, int get_names)
{
  char num_buf[8];
  char *name;

  sprintf (num_buf, "%d", frame);
  ui_out_text (uiout, "Frame ");
  ui_out_text(uiout, num_buf);
  ui_out_text(uiout, ": ");
  ui_out_list_begin (uiout, num_buf);
  ui_out_field_core_addr (uiout, "pc", pc);

  if (get_names)
    {
      ui_out_text (uiout, " func: ");

      find_pc_partial_function (pc, &name, NULL, NULL);
      if (name != NULL)
	ui_out_field_string (uiout, "func", name);
      else
	ui_out_field_skip (uiout, "func");
    }

  ui_out_text (uiout, " fp: ");
  ui_out_field_core_addr (uiout, "fp", fp);
  ui_out_text (uiout, "\n");
  ui_out_list_end (uiout);

}

/*
 * implementation for ppc-fast-show-stack command
 * prints the stack depth, a valid bit, and list
 * of the frames showing the pc & fp for each frame
 */

void
ppc_fast_show_stack (char *args, int from_tty)
{
  int get_names = 0;
  int show_frames = 1;
  int valid, count;
  char *argptr;
  int limit = 0;
  char *limit_str;

  if (args != NULL)
    {
      if (strstr (args, "noframe") != 0)
	show_frames = 0;
      else if (strstr (args, "frame") != 0)
	show_frames = 1;
      else
	show_frames = 1;

      if (show_frames)
	{
	  if (strstr (args, "noname") != 0)
	    get_names = 0;
	  else if (strstr (args, "name") != 0)
	    get_names = 1;
	  else
	    get_names = 0;

	}
      
      if ((limit_str = strstr (args, "limit")) != 0)
        {
          limit_str += 6; /* 'i' 'm' 'i' 't' ' ' */
          limit = atoi(limit_str);
        }
    }

  valid = ppc_fast_show_stack_helper (show_frames, get_names, limit, &count);

  ui_out_text (uiout, "Valid: ");
  ui_out_field_int (uiout, "valid", valid);
  ui_out_text (uiout, "\nCount: ");
  ui_out_field_int (uiout, "count", count);
  ui_out_text (uiout, "\n");
}

/* 
 * This is the helper function for ppc_fast_show_stack, but it is
 * also set to the FAST_COUNT_STACK macro for ppc.  The return value
 * is 1 if no errors were encountered traversing the stack, and 0 otherwise.
 * it sets count to the stack depth.  If SHOW_FRAMES is 1, then it also
 * emits a list of frame info bits, with the pc & fp for each frame to 
 * the current UI_OUT.  If GET_NAMES is 1, it also emits the names for
 * each frame (though this slows the function a good bit.)
 */

/*
 * LIMIT parameter sets a limit on the number of frames for
 * which the full information is printed.
 */

int
ppc_fast_show_stack_helper (int show_frames, int get_names, int limit, int *count)
{
  CORE_ADDR fp;
  static CORE_ADDR sigtramp_start = 0;
  static CORE_ADDR sigtramp_end = 0;
  struct frame_info *fi;
  int i = 0, valid = 0;
  unsigned long next_fp, pc;

  /* Get the first two frames.  If anything funky is going on, it will
     be here.  The second frame helps us get above frameless functions
     called from signal handlers...
     Above these frames we have to deal with sigtramps
     and alloca frames, that is about all. */  

  if (sigtramp_start == 0) 
    {
      char *name;
      struct minimal_symbol *msymbol;

      msymbol = lookup_minimal_symbol ("_sigtramp", NULL, NULL);
      if (msymbol == NULL)
	warning ("Couldn't find minimal symbol for \"_sigtramp\" - backtraces may be unreliable");
      else
	{
	  pc = SYMBOL_VALUE_ADDRESS (msymbol);
	  if (find_pc_partial_function (pc, &name, 
					&sigtramp_start, &sigtramp_end) == 0)
	    {
	      error ("Couldn't find _sigtramp symbol - backtraces will be unreliable");
	    }
	}
    }

  if (show_frames)
    ui_out_list_begin (uiout, "frames");
  
  i = 0;

  fi = get_current_frame();

  if (fi == NULL) 
    {
      goto ppc_count_finish;
    }

  if (show_frames)
    ppc_print_count_info (i, fi->frame, fi->pc, get_names);
  i = 1;
  valid = 1;

  fi = get_prev_frame(fi);
  if (fi == NULL)
    {
      goto ppc_count_finish;
    }

  pc = fi->pc;
  fp = fi->frame;

  if (show_frames)
    ppc_print_count_info (i, fp, pc, get_names);
  i = 2;
  
  if (safe_read_memory_unsigned_integer (fp, 4, &next_fp))
    {
      while (1) {
        if ((sigtramp_start<= pc) && (pc <= sigtramp_end))
	  {
	    fp = next_fp + 0x70 + 0xc;
	    if (!safe_read_memory_unsigned_integer (fp, 
						    4, &next_fp)) 
	      goto ppc_count_finish;

	    if (!safe_read_memory_unsigned_integer (fp - 0xc, 4, &pc))
	      goto ppc_count_finish;

	    fp = next_fp;
	    if (!safe_read_memory_unsigned_integer (fp, 4, &next_fp))
	      goto ppc_count_finish;
	  }
	else
	  {
	    fp = next_fp;
	    
	    if (!safe_read_memory_unsigned_integer (fp, 4, &next_fp))
	      goto ppc_count_finish;
	    
	    if (next_fp == 0)
	      {
		valid = 1;
		goto ppc_count_finish;
	      }
	    	    
	    if (i > 10000) 
	      goto ppc_count_finish;
	    
	    if (!safe_read_memory_unsigned_integer (fp + DEFAULT_LR_SAVE, 4, &pc))
	      goto ppc_count_finish;
	  }	

	if (show_frames && ((limit == 0) || (i < limit)))
          {
            ppc_print_count_info (i, fp, pc, get_names);
          }
	i++;
	
      }
    }

 ppc_count_finish:
  if (show_frames)
    ui_out_list_end (uiout);

  *count = i;
  return valid;
}

CORE_ADDR ppc_macosx_skip_trampoline_code (CORE_ADDR pc)
{
  return dyld_symbol_stub_function_address (pc, NULL);
}

CORE_ADDR ppc_macosx_dynamic_trampoline_nextpc (CORE_ADDR pc)
{
  return dyld_symbol_stub_function_address (pc, NULL);
}

int ppc_macosx_in_solib_dynsym_resolve_code (CORE_ADDR pc)
{
  return 0;
}

int ppc_macosx_in_solib_return_trampoline (CORE_ADDR pc, char *name)
{
  return 0;
}

int ppc_macosx_in_solib_call_trampoline (CORE_ADDR pc, char *name)
{
  if (ppc_macosx_skip_trampoline_code (pc) != 0) { return 1; }
  return 0;
}
void
_initialize_ppc_tdep ()
{
  struct cmd_list_element *cmd = NULL;

  register_gdbarch_init (bfd_arch_powerpc, ppc_gdbarch_init);

  tm_print_insn = print_insn_big_powerpc;

  cmd = add_set_cmd ("ppc", class_obscure, var_boolean, 
		     (char *) &ppc_debugflag,
		     "Set if printing PPC stack analysis debugging statements.",
		     &setdebuglist),
  add_show_from_set (cmd, &showdebuglist);		

  add_com ("ppc-fast-show-stack", class_obscure, ppc_fast_show_stack,
	   "List stack pc & frame pointers without building the stack info.\n\
If you pass the \"-name\" argument, it will also return function names.");

  cmd = add_set_cmd
    ("ppc-maximum-frame-size", class_obscure, var_uinteger,
     (char *) &ppc_max_frame_size,
     "Set the maximum size to expect for a valid PPC frame.",
     &setlist);
  add_show_from_set (cmd, &showlist);
}