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/* Target-dependent code for the NEC V850 for GDB, the GNU debugger.

   Copyright 1996, Free Software Foundation, 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 "defs.h"

#include "frame.h"

#include "inferior.h"

#include "obstack.h"

#include "target.h"

#include "value.h"

#include "bfd.h"

#include "gdb_string.h"

#include "gdbcore.h"

#include "symfile.h"

static char *v850_generic_reg_names[] = REGISTER_NAMES;

static char *v850e_reg_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",

  "eipc", "eipsw", "fepc", "fepsw", "ecr", "psw", "sr6", "sr7",

  "sr8", "sr9", "sr10", "sr11", "sr12", "sr13", "sr14", "sr15",

  "ctpc", "ctpsw", "dbpc", "dbpsw", "ctbp", "sr21", "sr22", "sr23",

  "sr24", "sr25", "sr26", "sr27", "sr28", "sr29", "sr30", "sr31",

  "pc", "fp"

};

char **v850_register_names = v850_generic_reg_names;

struct

  {

    char **regnames;

    int mach;

  }

v850_processor_type_table[] =

{

  {

    v850_generic_reg_names, bfd_mach_v850

  }

  ,

  {

    v850e_reg_names, bfd_mach_v850e

  }

  ,

  {

    v850e_reg_names, bfd_mach_v850ea

  }

  ,

  {

    NULL, 0

  }

};

/* Info gleaned from scanning a function's prologue.  */

struct pifsr                    /* Info about one saved reg */

  {

    int framereg;               /* Frame reg (SP or FP) */

    int offset;                 /* Offset from framereg */

    int cur_frameoffset;        /* Current frameoffset */

    int reg;                    /* Saved register number */

  };

struct prologue_info

  {

    int framereg;

    int frameoffset;

    int start_function;

    struct pifsr *pifsrs;

  };

static CORE_ADDR v850_scan_prologue PARAMS ((CORE_ADDR pc,

                                             struct prologue_info * fs));

/* Should call_function allocate stack space for a struct return?  */

int

v850_use_struct_convention (gcc_p, type)

     int gcc_p;

     struct type *type;

{

  return (TYPE_NFIELDS (type) > 1 || TYPE_LENGTH (type) > 4);

}

/* Structure for mapping bits in register lists to register numbers. */

struct reg_list

{

  long mask;

  int regno;

};

/* Helper function for v850_scan_prologue to handle prepare instruction. */

static void

handle_prepare (int insn, int insn2, CORE_ADDR * current_pc_ptr,

                struct prologue_info *pi, struct pifsr **pifsr_ptr)

{

  CORE_ADDR current_pc = *current_pc_ptr;

  struct pifsr *pifsr = *pifsr_ptr;

  long next = insn2 & 0xffff;

  long list12 = ((insn & 1) << 16) + (next & 0xffe0);

  long offset = (insn & 0x3e) << 1;

  static struct reg_list reg_table[] =

  {

    {0x00800, 20},              /* r20 */

    {0x00400, 21},              /* r21 */

    {0x00200, 22},              /* r22 */

    {0x00100, 23},              /* r23 */

    {0x08000, 24},              /* r24 */

    {0x04000, 25},              /* r25 */

    {0x02000, 26},              /* r26 */

    {0x01000, 27},              /* r27 */

    {0x00080, 28},              /* r28 */

    {0x00040, 29},              /* r29 */

    {0x10000, 30},              /* ep */

    {0x00020, 31},              /* lp */

    {0, 0}                        /* end of table */

  };

  int i;

  if ((next & 0x1f) == 0x0b)    /* skip imm16 argument */

    current_pc += 2;

  else if ((next & 0x1f) == 0x13)       /* skip imm16 argument */

    current_pc += 2;

  else if ((next & 0x1f) == 0x1b)       /* skip imm32 argument */

    current_pc += 4;

  /* Calculate the total size of the saved registers, and add it

     it to the immediate value used to adjust SP. */

  for (i = 0; reg_table[i].mask != 0; i++)

    if (list12 & reg_table[i].mask)

      offset += REGISTER_RAW_SIZE (regtable[i].regno);

  pi->frameoffset -= offset;

  /* Calculate the offsets of the registers relative to the value

     the SP will have after the registers have been pushed and the

     imm5 value has been subtracted from it. */

  if (pifsr)

    {

      for (i = 0; reg_table[i].mask != 0; i++)

        {

          if (list12 & reg_table[i].mask)

            {

              int reg = reg_table[i].regno;

              offset -= REGISTER_RAW_SIZE (reg);

              pifsr->reg = reg;

              pifsr->offset = offset;

              pifsr->cur_frameoffset = pi->frameoffset;

#ifdef DEBUG

              printf_filtered ("\tSaved register r%d, offset %d", reg, pifsr->offset);

#endif

              pifsr++;

            }

        }

    }

#ifdef DEBUG

  printf_filtered ("\tfound ctret after regsave func");

#endif

  /* Set result parameters. */

  *current_pc_ptr = current_pc;

  *pifsr_ptr = pifsr;

}

/* Helper function for v850_scan_prologue to handle pushm/pushl instructions.

   FIXME: the SR bit of the register list is not supported; must check

   that the compiler does not ever generate this bit. */

static void

handle_pushm (int insn, int insn2, struct prologue_info *pi,

              struct pifsr **pifsr_ptr)

{

  struct pifsr *pifsr = *pifsr_ptr;

  long list12 = ((insn & 0x0f) << 16) + (insn2 & 0xfff0);

  long offset = 0;

  static struct reg_list pushml_reg_table[] =

  {

    {0x80000, PS_REGNUM},       /* PSW */

    {0x40000, 1},               /* r1 */

    {0x20000, 2},               /* r2 */

    {0x10000, 3},               /* r3 */

    {0x00800, 4},               /* r4 */

    {0x00400, 5},               /* r5 */

    {0x00200, 6},               /* r6 */

    {0x00100, 7},               /* r7 */

    {0x08000, 8},               /* r8 */

    {0x04000, 9},               /* r9 */

    {0x02000, 10},              /* r10 */

    {0x01000, 11},              /* r11 */

    {0x00080, 12},              /* r12 */

    {0x00040, 13},              /* r13 */

    {0x00020, 14},              /* r14 */

    {0x00010, 15},              /* r15 */

    {0, 0}                        /* end of table */

  };

  static struct reg_list pushmh_reg_table[] =

  {

    {0x80000, 16},              /* r16 */

    {0x40000, 17},              /* r17 */

    {0x20000, 18},              /* r18 */

    {0x10000, 19},              /* r19 */

    {0x00800, 20},              /* r20 */

    {0x00400, 21},              /* r21 */

    {0x00200, 22},              /* r22 */

    {0x00100, 23},              /* r23 */

    {0x08000, 24},              /* r24 */

    {0x04000, 25},              /* r25 */

    {0x02000, 26},              /* r26 */

    {0x01000, 27},              /* r27 */

    {0x00080, 28},              /* r28 */

    {0x00040, 29},              /* r29 */

    {0x00010, 30},              /* r30 */

    {0x00020, 31},              /* r31 */

    {0, 0}                        /* end of table */

  };

  struct reg_list *reg_table;

  int i;

  /* Is this a pushml or a pushmh? */

  if ((insn2 & 7) == 1)

    reg_table = pushml_reg_table;

  else

    reg_table = pushmh_reg_table;

  /* Calculate the total size of the saved registers, and add it

     it to the immediate value used to adjust SP. */

  for (i = 0; reg_table[i].mask != 0; i++)

    if (list12 & reg_table[i].mask)

      offset += REGISTER_RAW_SIZE (regtable[i].regno);

  pi->frameoffset -= offset;

  /* Calculate the offsets of the registers relative to the value

     the SP will have after the registers have been pushed and the

     imm5 value is subtracted from it. */

  if (pifsr)

    {

      for (i = 0; reg_table[i].mask != 0; i++)

        {

          if (list12 & reg_table[i].mask)

            {

              int reg = reg_table[i].regno;

              offset -= REGISTER_RAW_SIZE (reg);

              pifsr->reg = reg;

              pifsr->offset = offset;

              pifsr->cur_frameoffset = pi->frameoffset;

#ifdef DEBUG

              printf_filtered ("\tSaved register r%d, offset %d", reg, pifsr->offset);

#endif

              pifsr++;

            }

        }

    }

#ifdef DEBUG

  printf_filtered ("\tfound ctret after regsave func");

#endif

  /* Set result parameters. */

  *pifsr_ptr = pifsr;

}

/* Function: scan_prologue

   Scan the prologue of the function that contains PC, and record what

   we find in PI.  PI->fsr must be zeroed by the called.  Returns the

   pc after the prologue.  Note that the addresses saved in pi->fsr

   are actually just frame relative (negative offsets from the frame

   pointer).  This is because we don't know the actual value of the

   frame pointer yet.  In some circumstances, the frame pointer can't

   be determined till after we have scanned the prologue.  */

static CORE_ADDR

v850_scan_prologue (pc, pi)

     CORE_ADDR pc;

     struct prologue_info *pi;

{

  CORE_ADDR func_addr, prologue_end, current_pc;

  struct pifsr *pifsr, *pifsr_tmp;

  int fp_used;

  int ep_used;

  int reg;

  CORE_ADDR save_pc, save_end;

  int regsave_func_p;

  int r12_tmp;

  /* First, figure out the bounds of the prologue so that we can limit the

     search to something reasonable.  */

  if (find_pc_partial_function (pc, NULL, &func_addr, NULL))

    {

      struct symtab_and_line sal;

      sal = find_pc_line (func_addr, 0);

      if (func_addr == entry_point_address ())

        pi->start_function = 1;

      else

        pi->start_function = 0;

#if 0

      if (sal.line == 0)

        prologue_end = pc;

      else

        prologue_end = sal.end;

#else

      prologue_end = pc;

#endif

    }

  else

    {                           /* We're in the boondocks */

      func_addr = pc - 100;

      prologue_end = pc;

    }

  prologue_end = min (prologue_end, pc);

  /* Now, search the prologue looking for instructions that setup fp, save

     rp, adjust sp and such.  We also record the frame offset of any saved

     registers. */

  pi->frameoffset = 0;

  pi->framereg = SP_REGNUM;

  fp_used = 0;

  ep_used = 0;

  pifsr = pi->pifsrs;

  regsave_func_p = 0;

  save_pc = 0;

  save_end = 0;

  r12_tmp = 0;

#ifdef DEBUG

  printf_filtered ("Current_pc = 0x%.8lx, prologue_end = 0x%.8lx\n",

                   (long) func_addr, (long) prologue_end);

#endif

  for (current_pc = func_addr; current_pc < prologue_end;)

    {

      int insn, insn2;

#ifdef DEBUG

      printf_filtered ("0x%.8lx ", (long) current_pc);

      (*tm_print_insn) (current_pc, &tm_print_insn_info);

#endif

      insn = read_memory_unsigned_integer (current_pc, 2);

      current_pc += 2;

      if ((insn & 0x0780) >= 0x0600)    /* Four byte instruction? */

        {

          insn2 = read_memory_unsigned_integer (current_pc, 2);

          current_pc += 2;

        }

      if ((insn & 0xffc0) == ((10 << 11) | 0x0780) && !regsave_func_p)

        {                       /* jarl <func>,10 */

          long low_disp = insn2 & ~(long) 1;

          long disp = (((((insn & 0x3f) << 16) + low_disp)

                        & ~(long) 1) ^ 0x00200000) - 0x00200000;

          save_pc = current_pc;

          save_end = prologue_end;

          regsave_func_p = 1;

          current_pc += disp - 4;

          prologue_end = (current_pc

                          + (2 * 3)     /* moves to/from ep */

                          + 4   /* addi <const>,sp,sp */

                          + 2   /* jmp [r10] */

                          + (2 * 12)    /* sst.w to save r2, r20-r29, r31 */

                          + 20);        /* slop area */

#ifdef DEBUG

          printf_filtered ("\tfound jarl <func>,r10, disp = %ld, low_disp = %ld, new pc = 0x%.8lx\n",

                           disp, low_disp, (long) current_pc + 2);

#endif

          continue;

        }

      else if ((insn & 0xffc0) == 0x0200 && !regsave_func_p)

        {                       /* callt <imm6> */

          long ctbp = read_register (CTBP_REGNUM);

          long adr = ctbp + ((insn & 0x3f) << 1);

          save_pc = current_pc;

          save_end = prologue_end;

          regsave_func_p = 1;

          current_pc = ctbp + (read_memory_unsigned_integer (adr, 2) & 0xffff);

          prologue_end = (current_pc

                          + (2 * 3)     /* prepare list2,imm5,sp/imm */

                          + 4   /* ctret */

                          + 20);        /* slop area */

#ifdef DEBUG

          printf_filtered ("\tfound callt,  ctbp = 0x%.8lx, adr = %.8lx, new pc = 0x%.8lx\n",

                           ctbp, adr, (long) current_pc);

#endif

          continue;

        }

      else if ((insn & 0xffc0) == 0x0780)       /* prepare list2,imm5 */

        {

          handle_prepare (insn, insn2, &current_pc, pi, &pifsr);

          continue;

        }

      else if (insn == 0x07e0 && regsave_func_p && insn2 == 0x0144)

        {                       /* ctret after processing register save function */

          current_pc = save_pc;

          prologue_end = save_end;

          regsave_func_p = 0;

#ifdef DEBUG

          printf_filtered ("\tfound ctret after regsave func");

#endif

          continue;

        }

      else if ((insn & 0xfff0) == 0x07e0 && (insn2 & 5) == 1)

        {                       /* pushml, pushmh */

          handle_pushm (insn, insn2, pi, &pifsr);

          continue;

        }

      else if ((insn & 0xffe0) == 0x0060 && regsave_func_p)

        {                       /* jmp after processing register save function */

          current_pc = save_pc;

          prologue_end = save_end;

          regsave_func_p = 0;

#ifdef DEBUG

          printf_filtered ("\tfound jmp after regsave func");

#endif

          continue;

        }

      else if ((insn & 0x07c0) == 0x0780        /* jarl or jr */

               || (insn & 0xffe0) == 0x0060     /* jmp */

               || (insn & 0x0780) == 0x0580)    /* branch */

        {

#ifdef DEBUG

          printf_filtered ("\n");

#endif

          break;                /* Ran into end of prologue */

        }

      else if ((insn & 0xffe0) == ((SP_REGNUM << 11) | 0x0240))         /* add <imm>,sp */

        pi->frameoffset += ((insn & 0x1f) ^ 0x10) - 0x10;

      else if (insn == ((SP_REGNUM << 11) | 0x0600 | SP_REGNUM))        /* addi <imm>,sp,sp */

        pi->frameoffset += insn2;

      else if (insn == ((FP_RAW_REGNUM << 11) | 0x0000 | SP_REGNUM))    /* mov sp,fp */

        {

          fp_used = 1;

          pi->framereg = FP_RAW_REGNUM;

        }

      else if (insn == ((R12_REGNUM << 11) | 0x0640 | R0_REGNUM))       /* movhi hi(const),r0,r12 */

        r12_tmp = insn2 << 16;

      else if (insn == ((R12_REGNUM << 11) | 0x0620 | R12_REGNUM))      /* movea lo(const),r12,r12 */

        r12_tmp += insn2;

      else if (insn == ((SP_REGNUM << 11) | 0x01c0 | R12_REGNUM) && r12_tmp)    /* add r12,sp */

        pi->frameoffset = r12_tmp;

      else if (insn == ((EP_REGNUM << 11) | 0x0000 | SP_REGNUM))        /* mov sp,ep */

        ep_used = 1;

      else if (insn == ((EP_REGNUM << 11) | 0x0000 | R1_REGNUM))        /* mov r1,ep */

        ep_used = 0;

      else if (((insn & 0x07ff) == (0x0760 | SP_REGNUM)         /* st.w <reg>,<offset>[sp] */

                || (fp_used

                    && (insn & 0x07ff) == (0x0760 | FP_RAW_REGNUM)))    /* st.w <reg>,<offset>[fp] */

               && pifsr

               && (((reg = (insn >> 11) & 0x1f) >= SAVE1_START_REGNUM && reg <= SAVE1_END_REGNUM)

                   || (reg >= SAVE2_START_REGNUM && reg <= SAVE2_END_REGNUM)

                 || (reg >= SAVE3_START_REGNUM && reg <= SAVE3_END_REGNUM)))

        {

          pifsr->reg = reg;

          pifsr->offset = insn2 & ~1;

          pifsr->cur_frameoffset = pi->frameoffset;

#ifdef DEBUG

          printf_filtered ("\tSaved register r%d, offset %d", reg, pifsr->offset);

#endif

          pifsr++;

        }

      else if (ep_used          /* sst.w <reg>,<offset>[ep] */

               && ((insn & 0x0781) == 0x0501)

               && pifsr

               && (((reg = (insn >> 11) & 0x1f) >= SAVE1_START_REGNUM && reg <= SAVE1_END_REGNUM)

                   || (reg >= SAVE2_START_REGNUM && reg <= SAVE2_END_REGNUM)

                 || (reg >= SAVE3_START_REGNUM && reg <= SAVE3_END_REGNUM)))

        {

          pifsr->reg = reg;

          pifsr->offset = (insn & 0x007e) << 1;

          pifsr->cur_frameoffset = pi->frameoffset;

#ifdef DEBUG

          printf_filtered ("\tSaved register r%d, offset %d", reg, pifsr->offset);

#endif

          pifsr++;

        }

#ifdef DEBUG

      printf_filtered ("\n");

#endif

    }

  if (pifsr)

    pifsr->framereg = 0; /* Tie off last entry */

  /* Fix up any offsets to the final offset.  If a frame pointer was created, use it

     instead of the stack pointer.  */

  for (pifsr_tmp = pi->pifsrs; pifsr_tmp && pifsr_tmp != pifsr; pifsr_tmp++)

    {

      pifsr_tmp->offset -= pi->frameoffset - pifsr_tmp->cur_frameoffset;

      pifsr_tmp->framereg = pi->framereg;

#ifdef DEBUG

      printf_filtered ("Saved register r%d, offset = %d, framereg = r%d\n",

                    pifsr_tmp->reg, pifsr_tmp->offset, pifsr_tmp->framereg);

#endif

    }

#ifdef DEBUG

  printf_filtered ("Framereg = r%d, frameoffset = %d\n", pi->framereg, pi->frameoffset);

#endif

  return current_pc;

}

/* Function: init_extra_frame_info

   Setup the frame's frame pointer, pc, and frame addresses for saved

   registers.  Most of the work is done in scan_prologue().

   Note that when we are called for the last frame (currently active frame),

   that fi->pc and fi->frame will already be setup.  However, fi->frame will

   be valid only if this routine uses FP.  For previous frames, fi-frame will

   always be correct (since that is derived from v850_frame_chain ()).

   We can be called with the PC in the call dummy under two circumstances.

   First, during normal backtracing, second, while figuring out the frame

   pointer just prior to calling the target function (see run_stack_dummy).  */

void

v850_init_extra_frame_info (fi)

     struct frame_info *fi;

{

  struct prologue_info pi;

  struct pifsr pifsrs[NUM_REGS + 1], *pifsr;

  if (fi->next)

    fi->pc = FRAME_SAVED_PC (fi->next);

  memset (fi->fsr.regs, '\000', sizeof fi->fsr.regs);

  /* The call dummy doesn't save any registers on the stack, so we can return

     now.  */

  if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame))

    return;

  pi.pifsrs = pifsrs;

  v850_scan_prologue (fi->pc, &pi);

  if (!fi->next && pi.framereg == SP_REGNUM)

    fi->frame = read_register (pi.framereg) - pi.frameoffset;

  for (pifsr = pifsrs; pifsr->framereg; pifsr++)

    {

      fi->fsr.regs[pifsr->reg] = pifsr->offset + fi->frame;

      if (pifsr->framereg == SP_REGNUM)

        fi->fsr.regs[pifsr->reg] += pi.frameoffset;

    }

}

/* Function: frame_chain

   Figure out the frame prior to FI.  Unfortunately, this involves

   scanning the prologue of the caller, which will also be done

   shortly by v850_init_extra_frame_info.  For the dummy frame, we

   just return the stack pointer that was in use at the time the

   function call was made.  */

CORE_ADDR

v850_frame_chain (fi)

     struct frame_info *fi;

{

  struct prologue_info pi;

  CORE_ADDR callers_pc, fp;

  /* First, find out who called us */

  callers_pc = FRAME_SAVED_PC (fi);

  /* If caller is a call-dummy, then our FP bears no relation to his FP! */

  fp = v850_find_callers_reg (fi, FP_RAW_REGNUM);

  if (PC_IN_CALL_DUMMY (callers_pc, fp, fp))

    return fp;                  /* caller is call-dummy: return oldest value of FP */

  /* Caller is NOT a call-dummy, so everything else should just work.

     Even if THIS frame is a call-dummy! */

  pi.pifsrs = NULL;

  v850_scan_prologue (callers_pc, &pi);

  if (pi.start_function)

    return 0;                    /* Don't chain beyond the start function */

  if (pi.framereg == FP_RAW_REGNUM)

    return v850_find_callers_reg (fi, pi.framereg);

  return fi->frame - pi.frameoffset;

}

/* Function: find_callers_reg

   Find REGNUM on the stack.  Otherwise, it's in an active register.

   One thing we might want to do here is to check REGNUM against the

   clobber mask, and somehow flag it as invalid if it isn't saved on

   the stack somewhere.  This would provide a graceful failure mode

   when trying to get the value of caller-saves registers for an inner

   frame.  */

CORE_ADDR

v850_find_callers_reg (fi, regnum)

     struct frame_info *fi;

     int regnum;

{

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