fr30-asm.c

来自「基于4个mips核的noc设计」· C语言 代码 · 共 590 行 · 第 1/2 页

    case FR30_OPERAND_U8 :
      errmsg = cgen_parse_unsigned_integer (cd, strp, FR30_OPERAND_U8, &fields->f_u8);
      break;
    case FR30_OPERAND_UDISP6 :
      errmsg = cgen_parse_unsigned_integer (cd, strp, FR30_OPERAND_UDISP6, &fields->f_udisp6);
      break;

    default :
      /* xgettext:c-format */
      fprintf (stderr, _("Unrecognized field %d while parsing.\n"), opindex);
      abort ();
  }

  return errmsg;
}

cgen_parse_fn * const fr30_cgen_parse_handlers[] = 
{
  parse_insn_normal,
};

void
fr30_cgen_init_asm (cd)
     CGEN_CPU_DESC cd;
{
  fr30_cgen_init_opcode_table (cd);
  fr30_cgen_init_ibld_table (cd);
  cd->parse_handlers = & fr30_cgen_parse_handlers[0];
  cd->parse_operand = fr30_cgen_parse_operand;
}


/* Default insn parser.

   The syntax string is scanned and operands are parsed and stored in FIELDS.
   Relocs are queued as we go via other callbacks.

   ??? Note that this is currently an all-or-nothing parser.  If we fail to
   parse the instruction, we return 0 and the caller will start over from
   the beginning.  Backtracking will be necessary in parsing subexpressions,
   but that can be handled there.  Not handling backtracking here may get
   expensive in the case of the m68k.  Deal with later.

   Returns NULL for success, an error message for failure.
*/

static const char *
parse_insn_normal (cd, insn, strp, fields)
     CGEN_CPU_DESC cd;
     const CGEN_INSN *insn;
     const char **strp;
     CGEN_FIELDS *fields;
{
  /* ??? Runtime added insns not handled yet.  */
  const CGEN_SYNTAX *syntax = CGEN_INSN_SYNTAX (insn);
  const char *str = *strp;
  const char *errmsg;
  const char *p;
  const unsigned char * syn;
#ifdef CGEN_MNEMONIC_OPERANDS
  /* FIXME: wip */
  int past_opcode_p;
#endif

  /* For now we assume the mnemonic is first (there are no leading operands).
     We can parse it without needing to set up operand parsing.
     GAS's input scrubber will ensure mnemonics are lowercase, but we may
     not be called from GAS.  */
  p = CGEN_INSN_MNEMONIC (insn);
  while (*p && tolower (*p) == tolower (*str))
    ++p, ++str;

  if (* p)
    return _("unrecognized instruction");

#ifndef CGEN_MNEMONIC_OPERANDS
  if (* str && !isspace (* str))
    return _("unrecognized instruction");
#endif

  CGEN_INIT_PARSE (cd);
  cgen_init_parse_operand (cd);
#ifdef CGEN_MNEMONIC_OPERANDS
  past_opcode_p = 0;
#endif

  /* We don't check for (*str != '\0') here because we want to parse
     any trailing fake arguments in the syntax string.  */
  syn = CGEN_SYNTAX_STRING (syntax);

  /* Mnemonics come first for now, ensure valid string.  */
  if (! CGEN_SYNTAX_MNEMONIC_P (* syn))
    abort ();

  ++syn;

  while (* syn != 0)
    {
      /* Non operand chars must match exactly.  */
      if (CGEN_SYNTAX_CHAR_P (* syn))
	{
	  /* FIXME: While we allow for non-GAS callers above, we assume the
	     first char after the mnemonic part is a space.  */
	  /* FIXME: We also take inappropriate advantage of the fact that
	     GAS's input scrubber will remove extraneous blanks.  */
	  if (tolower (*str) == tolower (CGEN_SYNTAX_CHAR (* syn)))
	    {
#ifdef CGEN_MNEMONIC_OPERANDS
	      if (* syn == ' ')
		past_opcode_p = 1;
#endif
	      ++ syn;
	      ++ str;
	    }
	  else
	    {
	      /* Syntax char didn't match.  Can't be this insn.  */
	      static char msg [80];
	      /* xgettext:c-format */
	      sprintf (msg, _("syntax error (expected char `%c', found `%c')"),
		       *syn, *str);
	      return msg;
	    }
	  continue;
	}

      /* We have an operand of some sort.  */
      errmsg = fr30_cgen_parse_operand (cd, CGEN_SYNTAX_FIELD (*syn),
					  &str, fields);
      if (errmsg)
	return errmsg;

      /* Done with this operand, continue with next one.  */
      ++ syn;
    }

  /* If we're at the end of the syntax string, we're done.  */
  if (* syn == '\0')
    {
      /* FIXME: For the moment we assume a valid `str' can only contain
	 blanks now.  IE: We needn't try again with a longer version of
	 the insn and it is assumed that longer versions of insns appear
	 before shorter ones (eg: lsr r2,r3,1 vs lsr r2,r3).  */
      while (isspace (* str))
	++ str;

      if (* str != '\0')
	return _("junk at end of line"); /* FIXME: would like to include `str' */

      return NULL;
    }

  /* We couldn't parse it.  */
  return _("unrecognized instruction");
}

/* Main entry point.
   This routine is called for each instruction to be assembled.
   STR points to the insn to be assembled.
   We assume all necessary tables have been initialized.
   The assembled instruction, less any fixups, is stored in BUF.
   Remember that if CGEN_INT_INSN_P then BUF is an int and thus the value
   still needs to be converted to target byte order, otherwise BUF is an array
   of bytes in target byte order.
   The result is a pointer to the insn's entry in the opcode table,
   or NULL if an error occured (an error message will have already been
   printed).

   Note that when processing (non-alias) macro-insns,
   this function recurses.

   ??? It's possible to make this cpu-independent.
   One would have to deal with a few minor things.
   At this point in time doing so would be more of a curiosity than useful
   [for example this file isn't _that_ big], but keeping the possibility in
   mind helps keep the design clean.  */

const CGEN_INSN *
fr30_cgen_assemble_insn (cd, str, fields, buf, errmsg)
     CGEN_CPU_DESC cd;
     const char *str;
     CGEN_FIELDS *fields;
     CGEN_INSN_BYTES_PTR buf;
     char **errmsg;
{
  const char *start;
  CGEN_INSN_LIST *ilist;
  const char *tmp_errmsg = NULL;

  /* Skip leading white space.  */
  while (isspace (* str))
    ++ str;

  /* The instructions are stored in hashed lists.
     Get the first in the list.  */
  ilist = CGEN_ASM_LOOKUP_INSN (cd, str);

  /* Keep looking until we find a match.  */

  start = str;
  for ( ; ilist != NULL ; ilist = CGEN_ASM_NEXT_INSN (ilist))
    {
      const CGEN_INSN *insn = ilist->insn;

#ifdef CGEN_VALIDATE_INSN_SUPPORTED 
      /* not usually needed as unsupported opcodes shouldn't be in the hash lists */
      /* Is this insn supported by the selected cpu?  */
      if (! fr30_cgen_insn_supported (cd, insn))
	continue;
#endif

      /* If the RELAX attribute is set, this is an insn that shouldn't be
	 chosen immediately.  Instead, it is used during assembler/linker
	 relaxation if possible.  */
      if (CGEN_INSN_ATTR_VALUE (insn, CGEN_INSN_RELAX) != 0)
	continue;

      str = start;

      /* Allow parse/insert handlers to obtain length of insn.  */
      CGEN_FIELDS_BITSIZE (fields) = CGEN_INSN_BITSIZE (insn);

      tmp_errmsg = CGEN_PARSE_FN (cd, insn) (cd, insn, & str, fields);
      if (tmp_errmsg != NULL)
	continue;

      /* ??? 0 is passed for `pc' */
      tmp_errmsg = CGEN_INSERT_FN (cd, insn) (cd, insn, fields, buf,
					      (bfd_vma) 0);
      if (tmp_errmsg != NULL)
        continue;

      /* It is up to the caller to actually output the insn and any
         queued relocs.  */
      return insn;
    }

  /* Make sure we leave this with something at this point. */
  if (tmp_errmsg == NULL)
    tmp_errmsg = "unknown mnemonic";

  {
    static char errbuf[150];

#ifdef CGEN_VERBOSE_ASSEMBLER_ERRORS
    /* if verbose error messages, use errmsg from CGEN_PARSE_FN */
    if (strlen (start) > 50)
      /* xgettext:c-format */
      sprintf (errbuf, "%s `%.50s...'", tmp_errmsg, start);
    else 
      /* xgettext:c-format */
      sprintf (errbuf, "%s `%.50s'", tmp_errmsg, start);
#else
    if (strlen (start) > 50)
      /* xgettext:c-format */
      sprintf (errbuf, _("bad instruction `%.50s...'"), start);
    else 
      /* xgettext:c-format */
      sprintf (errbuf, _("bad instruction `%.50s'"), start);
#endif
      
    *errmsg = errbuf;
    return NULL;
  }
}

#if 0 /* This calls back to GAS which we can't do without care.  */

/* Record each member of OPVALS in the assembler's symbol table.
   This lets GAS parse registers for us.
   ??? Interesting idea but not currently used.  */

/* Record each member of OPVALS in the assembler's symbol table.
   FIXME: Not currently used.  */

void
fr30_cgen_asm_hash_keywords (cd, opvals)
     CGEN_CPU_DESC cd;
     CGEN_KEYWORD *opvals;
{
  CGEN_KEYWORD_SEARCH search = cgen_keyword_search_init (opvals, NULL);
  const CGEN_KEYWORD_ENTRY * ke;

  while ((ke = cgen_keyword_search_next (& search)) != NULL)
    {
#if 0 /* Unnecessary, should be done in the search routine.  */
      if (! fr30_cgen_opval_supported (ke))
	continue;
#endif
      cgen_asm_record_register (cd, ke->name, ke->value);
    }
}

#endif /* 0 */