ld-insn.c

这个是LINUX下的GDB调度工具的源码

/* The IGEN simulator generator for GDB, the GNU Debugger.

   Copyright 2002 Free Software Foundation, Inc.

   Contributed by Andrew Cagney.

   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 "misc.h"
#include "lf.h"
#include "table.h"
#include "filter.h"
#include "igen.h"
#include "ld-insn.h"

static insn_word_entry *
parse_insn_word (line_ref *line, char *string, int word_nr)
{
  char *chp;
  insn_word_entry *word = ZALLOC (insn_word_entry);

  /* create a leading sentinal */
  word->first = ZALLOC (insn_field_entry);
  word->first->first = -1;
  word->first->last = -1;
  word->first->width = 0;

  /* and a trailing sentinal */
  word->last = ZALLOC (insn_field_entry);
  word->last->first = options.insn_bit_size;
  word->last->last = options.insn_bit_size;
  word->last->width = 0;

  /* link them together */
  word->first->next = word->last;
  word->last->prev = word->first;

  /* now work through the formats */
  chp = skip_spaces (string);

  while (*chp != '\0')
    {
      char *start_pos;
      int strlen_pos;
      char *start_val;
      int strlen_val;
      insn_field_entry *new_field;

      /* create / link in the new field */
      new_field = ZALLOC (insn_field_entry);
      new_field->next = word->last;
      new_field->prev = word->last->prev;
      new_field->next->prev = new_field;
      new_field->prev->next = new_field;
      new_field->word_nr = word_nr;

      /* break out the first field (if present) */
      start_pos = chp;
      chp = skip_to_separator (chp, ".,!");
      strlen_pos = back_spaces (start_pos, chp) - start_pos;

      /* break out the second field (if present) */
      if (*chp != '.')
	{
	  /* assume what was specified was the value (and not the start
	     position).  Assume the value length implicitly specifies
	     the number of bits */
	  start_val = start_pos;
	  strlen_val = strlen_pos;
	  start_pos = "";
	  strlen_pos = 0;
	}
      else
	{
	  chp++;		/* skip `.' */
	  chp = skip_spaces (chp);
	  start_val = chp;
	  if (*chp == '/' || *chp == '*')
	    {
	      do
		{
		  chp++;
		}
	      while (*chp == '/' || *chp == '*');
	    }
	  else if (isalpha (*start_val))
	    {
	      do
		{
		  chp++;
		}
	      while (isalnum (*chp) || *chp == '_');
	    }
	  else if (isdigit (*start_val))
	    {
	      do
		{
		  chp++;
		}
	      while (isalnum (*chp));
	    }
	  strlen_val = chp - start_val;
	  chp = skip_spaces (chp);
	}
      if (strlen_val == 0)
	error (line, "Empty value field\n");

      /* break out any conditional fields - { [ "!" | "=" [ <value> | <field-name> } */
      while (*chp == '!' || *chp == '=')
	{
	  char *start;
	  char *end;
	  int len;
	  insn_field_cond *new_cond = ZALLOC (insn_field_cond);

	  /* determine the conditional test */
	  switch (*chp)
	    {
	    case '=':
	      new_cond->test = insn_field_cond_eq;
	      break;
	    case '!':
	      new_cond->test = insn_field_cond_ne;
	      break;
	    default:
	      ASSERT (0);
	    }

	  /* save the value */
	  chp++;
	  chp = skip_spaces (chp);
	  start = chp;
	  chp = skip_to_separator (chp, "+,:!=");
	  end = back_spaces (start, chp);
	  len = end - start;
	  if (len == 0)
	    error (line, "Missing or invalid conditional value\n");
	  new_cond->string = NZALLOC (char, len + 1);
	  strncpy (new_cond->string, start, len);

	  /* determine the conditional type */
	  if (isdigit (*start))
	    {
	      /* [ "!" | "=" ] <value> */
	      new_cond->type = insn_field_cond_value;
	      new_cond->value = a2i (new_cond->string);
	    }
	  else
	    {
	      /* [ "!" | "=" ] <field>  - check field valid */
	      new_cond->type = insn_field_cond_field;
	      /* new_cond->field is determined in later */
	    }

	  /* Only a single `=' is permitted. */
	  if ((new_cond->test == insn_field_cond_eq
	       && new_field->conditions != NULL)
	      || (new_field->conditions != NULL
		  && new_field->conditions->test == insn_field_cond_eq))
	    error (line, "Only single conditional when `=' allowed\n");

	  /* insert it */
	  {
	    insn_field_cond **last = &new_field->conditions;
	    while (*last != NULL)
	      last = &(*last)->next;
	    *last = new_cond;
	  }
	}

      /* NOW verify that the field was finished */
      if (*chp == ',')
	{
	  chp = skip_spaces (chp + 1);
	  if (*chp == '\0')
	    error (line, "empty field\n");
	}
      else if (*chp != '\0')
	{
	  error (line, "Missing field separator\n");
	}

      /* copy the value */
      new_field->val_string = NZALLOC (char, strlen_val + 1);
      strncpy (new_field->val_string, start_val, strlen_val);
      if (isdigit (new_field->val_string[0]))
	{
	  if (strlen_pos == 0)
	    {
	      /* when the length/pos field is omited, an integer field
	         is always binary */
	      unsigned64 val = 0;
	      int i;
	      for (i = 0; i < strlen_val; i++)
		{
		  if (new_field->val_string[i] != '0'
		      && new_field->val_string[i] != '1')
		    error (line, "invalid binary field %s\n",
			   new_field->val_string);
		  val = (val << 1) + (new_field->val_string[i] == '1');
		}
	      new_field->val_int = val;
	      new_field->type = insn_field_int;
	    }
	  else
	    {
	      new_field->val_int = a2i (new_field->val_string);
	      new_field->type = insn_field_int;
	    }
	}
      else if (new_field->val_string[0] == '/')
	{
	  new_field->type = insn_field_reserved;
	}
      else if (new_field->val_string[0] == '*')
	{
	  new_field->type = insn_field_wild;
	}
      else
	{
	  new_field->type = insn_field_string;
	  if (filter_is_member (word->field_names, new_field->val_string))
	    error (line, "Field name %s is duplicated\n",
		   new_field->val_string);
	  filter_parse (&word->field_names, new_field->val_string);
	}
      if (new_field->type != insn_field_string
	  && new_field->conditions != NULL)
	error (line, "Conditionals can only be applied to named fields\n");

      /* the copy the position */
      new_field->pos_string = NZALLOC (char, strlen_pos + 1);
      strncpy (new_field->pos_string, start_pos, strlen_pos);
      if (strlen_pos == 0)
	{
	  new_field->first = new_field->prev->last + 1;
	  if (new_field->first == 0	/* first field */
	      && *chp == '\0'	/* no further fields */
	      && new_field->type == insn_field_string)
	    {
	      /* A single string without any position, assume that it
	         represents the entire instruction word */
	      new_field->width = options.insn_bit_size;
	    }
	  else
	    {
	      /* No explicit width/position, assume value implicitly
	         supplies the width */
	      new_field->width = strlen_val;
	    }
	  new_field->last = new_field->first + new_field->width - 1;
	  if (new_field->last >= options.insn_bit_size)
	    error (line, "Bit position %d exceed instruction bit size (%d)\n",
		   new_field->last, options.insn_bit_size);
	}
      else if (options.insn_specifying_widths)
	{
	  new_field->first = new_field->prev->last + 1;
	  new_field->width = a2i (new_field->pos_string);
	  new_field->last = new_field->first + new_field->width - 1;
	  if (new_field->last >= options.insn_bit_size)
	    error (line, "Bit position %d exceed instruction bit size (%d)\n",
		   new_field->last, options.insn_bit_size);
	}
      else
	{
	  new_field->first = target_a2i (options.hi_bit_nr,
					 new_field->pos_string);
	  new_field->last = new_field->next->first - 1;	/* guess */
	  new_field->width = new_field->last - new_field->first + 1;	/* guess */
	  new_field->prev->last = new_field->first - 1;	/*fix */
	  new_field->prev->width = new_field->first - new_field->prev->first;	/*fix */
	}
    }

  /* fiddle first/last so that the sentinals disapear */
  ASSERT (word->first->last < 0);
  ASSERT (word->last->first >= options.insn_bit_size);
  word->first = word->first->next;
  word->last = word->last->prev;

  /* check that the last field goes all the way to the last bit */
  if (word->last->last != options.insn_bit_size - 1)
    {
      if (options.warn.width)
	options.warning (line, "Instruction format is not %d bits wide\n",
			 options.insn_bit_size);
      word->last->last = options.insn_bit_size - 1;
    }

  /* now go over this again, pointing each bit position at a field
     record */
  {
    insn_field_entry *field;
    for (field = word->first;
	 field->last < options.insn_bit_size; field = field->next)
      {
	int i;
	for (i = field->first; i <= field->last; i++)
	  {
	    word->bit[i] = ZALLOC (insn_bit_entry);
	    word->bit[i]->field = field;
	    switch (field->type)
	      {
	      case insn_field_invalid:
		ASSERT (0);
		break;
	      case insn_field_int:
		word->bit[i]->mask = 1;
		word->bit[i]->value = ((field->val_int
					& ((insn_uint) 1 <<
					   (field->last - i))) != 0);
	      case insn_field_reserved:
	      case insn_field_wild:
	      case insn_field_string:
		/* if we encounter a constant conditional, encode
		   their bit value. */
		if (field->conditions != NULL
		    && field->conditions->test == insn_field_cond_eq
		    && field->conditions->type == insn_field_cond_value)
		  {
		    word->bit[i]->mask = 1;
		    word->bit[i]->value = ((field->conditions->value
					    & ((insn_uint) 1 <<
					       (field->last - i))) != 0);
		  }
		break;
	      }
	  }
      }
  }

  return word;
}


static void
parse_insn_words (insn_entry * insn, char *formats)
{
  insn_word_entry **last_word = &insn->words;
  char *chp;

  /* now work through the formats */
  insn->nr_words = 0;
  chp = formats;

  while (1)
    {
      char *start_pos;
      char *end_pos;
      int strlen_pos;
      char *format;
      insn_word_entry *new_word;

      /* skip leading spaces */
      chp = skip_spaces (chp);

      /* break out the format */
      start_pos = chp;
      chp = skip_to_separator (chp, "+");
      end_pos = back_spaces (start_pos, chp);
      strlen_pos = end_pos - start_pos;

      /* check that something was there */
      if (strlen_pos == 0)
	error (insn->line, "missing or empty instruction format\n");

      /* parse the field */
      format = NZALLOC (char, strlen_pos + 1);
      strncpy (format, start_pos, strlen_pos);
      new_word = parse_insn_word (insn->line, format, insn->nr_words);
      insn->nr_words++;
      if (filter_is_common (insn->field_names, new_word->field_names))
	error (insn->line, "Field name duplicated between two words\n");
      filter_add (&insn->field_names, new_word->field_names);

      /* insert it */
      *last_word = new_word;
      last_word = &new_word->next;

      /* last format? */
      if (*chp == '\0')
	break;
      ASSERT (*chp == '+');
      chp++;
    }

  /* create a quick access array (indexed by word) of the same structure */
  {
    int i;
    insn_word_entry *word;
    insn->word = NZALLOC (insn_word_entry *, insn->nr_words + 1);
    for (i = 0, word = insn->words;
	 i < insn->nr_words; i++, word = word->next)
      insn->word[i] = word;
  }

  /* Go over all fields that have conditionals refering to other
     fields.  Link the fields up.  Verify that the two fields have the
     same size. Verify that the two fields are different */
  {
    int i;
    for (i = 0; i < insn->nr_words; i++)
      {
	insn_word_entry *word = insn->word[i];
	insn_field_entry *f;
	for (f = word->first; f->last < options.insn_bit_size; f = f->next)
	  {
	    insn_field_cond *cond;
	    for (cond = f->conditions; cond != NULL; cond = cond->next)
	      {
		if (cond->type == insn_field_cond_field)
		  {
		    int j;
		    if (strcmp (cond->string, f->val_string) == 0)
		      error (insn->line,
			     "Conditional `%s' of field `%s' refers to its self\n",
			     cond->string, f->val_string);
		    for (j = 0; j <= i && cond->field == NULL; j++)
		      {
			insn_word_entry *refered_word = insn->word[j];
			insn_field_entry *refered_field;
			for (refered_field = refered_word->first;
			     refered_field != NULL && cond->field == NULL;
			     refered_field = refered_field->next)
			  {
			    if (refered_field->type == insn_field_string
				&& strcmp (refered_field->val_string,
					   cond->string) == 0)
			      {
				/* found field being refered to by conditonal */
				cond->field = refered_field;
				/* check refered to and this field are
				   the same size */