io.c

gcc-fortran,linux使用fortran的编译软件。很好用的。

  return SUCCESS;
}


/* Free a gfc_filepos structure.  */

void
gfc_free_filepos (gfc_filepos * fp)
{

  gfc_free_expr (fp->unit);
  gfc_free_expr (fp->iomsg);
  gfc_free_expr (fp->iostat);
  gfc_free (fp);
}


/* Match elements of a REWIND, BACKSPACE, ENDFILE, or FLUSH statement.  */

static match
match_file_element (gfc_filepos * fp)
{
  match m;

  m = match_etag (&tag_unit, &fp->unit);
  if (m != MATCH_NO)
    return m;
  m = match_out_tag (&tag_iomsg, &fp->iomsg);
  if (m != MATCH_NO)
    return m;
  m = match_out_tag (&tag_iostat, &fp->iostat);
  if (m != MATCH_NO)
    return m;
  m = match_ltag (&tag_err, &fp->err);
  if (m != MATCH_NO)
    return m;

  return MATCH_NO;
}


/* Match the second half of the file-positioning statements, REWIND,
   BACKSPACE, ENDFILE, or the FLUSH statement.  */

static match
match_filepos (gfc_statement st, gfc_exec_op op)
{
  gfc_filepos *fp;
  match m;

  fp = gfc_getmem (sizeof (gfc_filepos));

  if (gfc_match_char ('(') == MATCH_NO)
    {
      m = gfc_match_expr (&fp->unit);
      if (m == MATCH_ERROR)
	goto cleanup;
      if (m == MATCH_NO)
	goto syntax;

      goto done;
    }

  m = match_file_element (fp);
  if (m == MATCH_ERROR)
    goto done;
  if (m == MATCH_NO)
    {
      m = gfc_match_expr (&fp->unit);
      if (m == MATCH_ERROR)
	goto done;
      if (m == MATCH_NO)
	goto syntax;
    }

  for (;;)
    {
      if (gfc_match_char (')') == MATCH_YES)
	break;
      if (gfc_match_char (',') != MATCH_YES)
	goto syntax;

      m = match_file_element (fp);
      if (m == MATCH_ERROR)
	goto cleanup;
      if (m == MATCH_NO)
	goto syntax;
    }

done:
  if (gfc_match_eos () != MATCH_YES)
    goto syntax;

  if (gfc_pure (NULL))
    {
      gfc_error ("%s statement not allowed in PURE procedure at %C",
		 gfc_ascii_statement (st));

      goto cleanup;
    }

  new_st.op = op;
  new_st.ext.filepos = fp;
  return MATCH_YES;

syntax:
  gfc_syntax_error (st);

cleanup:
  gfc_free_filepos (fp);
  return MATCH_ERROR;
}


try
gfc_resolve_filepos (gfc_filepos * fp)
{

  RESOLVE_TAG (&tag_unit, fp->unit);
  RESOLVE_TAG (&tag_iostat, fp->iostat);
  RESOLVE_TAG (&tag_iomsg, fp->iomsg);
  if (gfc_reference_st_label (fp->err, ST_LABEL_TARGET) == FAILURE)
    return FAILURE;

  return SUCCESS;
}


/* Match the file positioning statements: ENDFILE, BACKSPACE, REWIND,
   and the FLUSH statement.  */

match
gfc_match_endfile (void)
{

  return match_filepos (ST_END_FILE, EXEC_ENDFILE);
}

match
gfc_match_backspace (void)
{

  return match_filepos (ST_BACKSPACE, EXEC_BACKSPACE);
}

match
gfc_match_rewind (void)
{

  return match_filepos (ST_REWIND, EXEC_REWIND);
}

match
gfc_match_flush (void)
{
  if (gfc_notify_std (GFC_STD_F2003, "Fortran 2003: FLUSH statement at %C") == FAILURE)
    return MATCH_ERROR;

  return match_filepos (ST_FLUSH, EXEC_FLUSH);
}

/******************** Data Transfer Statements *********************/

typedef enum
{ M_READ, M_WRITE, M_PRINT, M_INQUIRE }
io_kind;


/* Return a default unit number.  */

static gfc_expr *
default_unit (io_kind k)
{
  int unit;

  if (k == M_READ)
    unit = 5;
  else
    unit = 6;

  return gfc_int_expr (unit);
}


/* Match a unit specification for a data transfer statement.  */

static match
match_dt_unit (io_kind k, gfc_dt * dt)
{
  gfc_expr *e;

  if (gfc_match_char ('*') == MATCH_YES)
    {
      if (dt->io_unit != NULL)
	goto conflict;

      dt->io_unit = default_unit (k);
      return MATCH_YES;
    }

  if (gfc_match_expr (&e) == MATCH_YES)
    {
      if (dt->io_unit != NULL)
	{
	  gfc_free_expr (e);
	  goto conflict;
	}

      dt->io_unit = e;
      return MATCH_YES;
    }

  return MATCH_NO;

conflict:
  gfc_error ("Duplicate UNIT specification at %C");
  return MATCH_ERROR;
}


/* Match a format specification.  */

static match
match_dt_format (gfc_dt * dt)
{
  locus where;
  gfc_expr *e;
  gfc_st_label *label;

  where = gfc_current_locus;

  if (gfc_match_char ('*') == MATCH_YES)
    {
      if (dt->format_expr != NULL || dt->format_label != NULL)
	goto conflict;

      dt->format_label = &format_asterisk;
      return MATCH_YES;
    }

  if (gfc_match_st_label (&label) == MATCH_YES)
    {
      if (dt->format_expr != NULL || dt->format_label != NULL)
	{
	  gfc_free_st_label (label);
	  goto conflict;
	}

      if (gfc_reference_st_label (label, ST_LABEL_FORMAT) == FAILURE)
	return MATCH_ERROR;

      dt->format_label = label;
      return MATCH_YES;
    }

  if (gfc_match_expr (&e) == MATCH_YES)
    {
      if (dt->format_expr != NULL || dt->format_label != NULL)
	{
	  gfc_free_expr (e);
	  goto conflict;
	}
      dt->format_expr = e;
      return MATCH_YES;
    }

  gfc_current_locus = where;	/* The only case where we have to restore */

  return MATCH_NO;

conflict:
  gfc_error ("Duplicate format specification at %C");
  return MATCH_ERROR;
}


/* Traverse a namelist that is part of a READ statement to make sure
   that none of the variables in the namelist are INTENT(IN).  Returns
   nonzero if we find such a variable.  */

static int
check_namelist (gfc_symbol * sym)
{
  gfc_namelist *p;

  for (p = sym->namelist; p; p = p->next)
    if (p->sym->attr.intent == INTENT_IN)
      {
	gfc_error ("Symbol '%s' in namelist '%s' is INTENT(IN) at %C",
		   p->sym->name, sym->name);
	return 1;
      }

  return 0;
}


/* Match a single data transfer element.  */

static match
match_dt_element (io_kind k, gfc_dt * dt)
{
  char name[GFC_MAX_SYMBOL_LEN + 1];
  gfc_symbol *sym;
  match m;

  if (gfc_match (" unit =") == MATCH_YES)
    {
      m = match_dt_unit (k, dt);
      if (m != MATCH_NO)
	return m;
    }

  if (gfc_match (" fmt =") == MATCH_YES)
    {
      m = match_dt_format (dt);
      if (m != MATCH_NO)
	return m;
    }

  if (gfc_match (" nml = %n", name) == MATCH_YES)
    {
      if (dt->namelist != NULL)
	{
	  gfc_error ("Duplicate NML specification at %C");
	  return MATCH_ERROR;
	}

      if (gfc_find_symbol (name, NULL, 1, &sym))
	return MATCH_ERROR;

      if (sym == NULL || sym->attr.flavor != FL_NAMELIST)
	{
	  gfc_error ("Symbol '%s' at %C must be a NAMELIST group name",
		     sym != NULL ? sym->name : name);
	  return MATCH_ERROR;
	}

      dt->namelist = sym;
      if (k == M_READ && check_namelist (sym))
	return MATCH_ERROR;

      return MATCH_YES;
    }

  m = match_etag (&tag_rec, &dt->rec);
  if (m != MATCH_NO)
    return m;
  m = match_out_tag (&tag_iomsg, &dt->iomsg);
  if (m != MATCH_NO)
    return m;
  m = match_out_tag (&tag_iostat, &dt->iostat);
  if (m != MATCH_NO)
    return m;
  m = match_ltag (&tag_err, &dt->err);
  if (m == MATCH_YES)
    dt->err_where = gfc_current_locus;
  if (m != MATCH_NO)
    return m;
  m = match_etag (&tag_advance, &dt->advance);
  if (m != MATCH_NO)
    return m;
  m = match_out_tag (&tag_size, &dt->size);
  if (m != MATCH_NO)
    return m;

  m = match_ltag (&tag_end, &dt->end);
  if (m == MATCH_YES)
    {
      if (k == M_WRITE)
       {
         gfc_error ("END tag at %C not allowed in output statement");
         return MATCH_ERROR;
       }
      dt->end_where = gfc_current_locus;
    }
  if (m != MATCH_NO)
    return m;

  m = match_ltag (&tag_eor, &dt->eor);
  if (m == MATCH_YES)
    dt->eor_where = gfc_current_locus;
  if (m != MATCH_NO)
    return m;

  return MATCH_NO;
}


/* Free a data transfer structure and everything below it.  */

void
gfc_free_dt (gfc_dt * dt)
{

  if (dt == NULL)
    return;

  gfc_free_expr (dt->io_unit);
  gfc_free_expr (dt->format_expr);
  gfc_free_expr (dt->rec);
  gfc_free_expr (dt->advance);
  gfc_free_expr (dt->iomsg);
  gfc_free_expr (dt->iostat);
  gfc_free_expr (dt->size);

  gfc_free (dt);
}


/* Resolve everything in a gfc_dt structure.  */

try
gfc_resolve_dt (gfc_dt * dt)
{
  gfc_expr *e;

  RESOLVE_TAG (&tag_format, dt->format_expr);
  RESOLVE_TAG (&tag_rec, dt->rec);
  RESOLVE_TAG (&tag_advance, dt->advance);
  RESOLVE_TAG (&tag_iomsg, dt->iomsg);
  RESOLVE_TAG (&tag_iostat, dt->iostat);
  RESOLVE_TAG (&tag_size, dt->size);

  e = dt->io_unit;
  if (gfc_resolve_expr (e) == SUCCESS
      && (e->ts.type != BT_INTEGER
	  && (e->ts.type != BT_CHARACTER
	      || e->expr_type != EXPR_VARIABLE)))
    {
      gfc_error
	("UNIT specification at %L must be an INTEGER expression or a "
	 "CHARACTER variable", &e->where);
      return FAILURE;
    }

  if (e->ts.type == BT_CHARACTER)
    {
      if (gfc_has_vector_index (e))
	{
	  gfc_error ("Internal unit with vector subscript at %L",
		     &e->where);
	  return FAILURE;
	}
    }

  if (e->rank && e->ts.type != BT_CHARACTER)
    {
      gfc_error ("External IO UNIT cannot be an array at %L", &e->where);
      return FAILURE;
    }

  if (dt->err)
    {
      if (gfc_reference_st_label (dt->err, ST_LABEL_TARGET) == FAILURE)
	return FAILURE;
      if (dt->err->defined == ST_LABEL_UNKNOWN)
	{
	  gfc_error ("ERR tag label %d at %L not defined",
		      dt->err->value, &dt->err_where);
	  return FAILURE;
	}
    }

  if (dt->end)
    {
      if (gfc_reference_st_label (dt->end, ST_LABEL_TARGET) == FAILURE)
	return FAILURE;
      if (dt->end->defined == ST_LABEL_UNKNOWN)
	{
	  gfc_error ("END tag label %d at %L not defined",
		      dt->end->value, &dt->end_where);
	  return FAILURE;
	}
    }

  if (dt->eor)
    {
      if (gfc_reference_st_label (dt->eor, ST_LABEL_TARGET) == FAILURE)
	return FAILURE;
      if (dt->eor->defined == ST_LABEL_UNKNOWN)
	{
	  gfc_error ("EOR tag label %d at %L not defined",
		      dt->eor->value, &dt->eor_where);
	  return FAILURE;
	}
    }

  /* Check the format label actually exists.  */
  if (dt->format_label && dt->format_label != &format_asterisk
      && dt->format_label->defined == ST_LABEL_UNKNOWN)
    {
      gfc_error ("FORMAT label %d at %L not defined", dt->format_label->value,
	         &dt->format_label->where);
      return FAILURE;
    }
  return SUCCESS;
}


/* Given an io_kind, return its name.  */

static const char *
io_kind_name (io_kind k)
{
  const char *name;

  switch (k)
    {
    case M_READ:
      name = "READ";
      break;
    case M_WRITE:
      name = "WRITE";
      break;
    case M_PRINT:
      name = "PRINT";
      break;
    case M_INQUIRE:
      name = "INQUIRE";
      break;
    default:
      gfc_internal_error ("io_kind_name(): bad I/O-kind");
    }

  return name;
}


/* Match an IO iteration statement of the form:

   ( [<IO element> ,] <IO element>, I = <expr>, <expr> [, <expr> ] )

   which is equivalent to a single IO element.  This function is
   mutually recursive with match_io_element().  */

static match match_io_element (io_kind k, gfc_code **);

static match
match_io_iterator (io_kind k, gfc_code ** result)
{
  gfc_code *head, *tail, *new;
  gfc_iterator *iter;
  locus old_loc;
  match m;
  int n;

  iter = NULL;
  head = NULL;
  old_loc = gfc_current_locus;

  if (gfc_match_char ('(') != MATCH_YES)
    return MATCH_NO;

  m = match_io_element (k, &head);
  tail = head;

  if (m != MATCH_YES || gfc_match_char (',') != MATCH_YES)
    {
      m = MATCH_NO;
      goto cleanup;
    }

  /* Can't be anything but an IO iterator.  Build a list.  */
  iter = gfc_get_iterator ();

  for (n = 1;; n++)
    {
      m = gfc_match_iterator (iter, 0);
      if (m == MATCH_ERROR)
	goto cleanup;
      if (m == MATCH_YES)
	{
	  gfc_check_do_variable (iter->var->symtree);
	  break;
	}

      m = match_io_element (k, &new);
      if (m == MATCH_ERROR)
	goto cleanup;
      if (m == MATCH_NO)
	{
	  if (n > 2)
	    goto syntax;
	  goto cleanup;
	}

      tail = gfc_append_code (tail, new);

      if (gfc_match_char (',') != MATCH_YES)
	{
	  if (n > 2)
	    goto syntax;
	  m = MATCH_NO;
	  goto cleanup;
	}
    }

  if (gfc_match_char (')') != MATCH_YES)
    goto syntax;

  new = gfc_get_code ();
  new->op = EXEC_DO;
  new->ext.iterator = iter;

  new->block = gfc_get_code ();
  new->block->op = EXEC_DO;
  new->block->next = head;

  *result = new;
  return MATCH_YES;

syntax:
  gfc_error ("Syntax error in I/O iterator at %C");
  m = MATCH_ERROR;

cleanup:
  gfc_free_iterator (iter, 1);
  gfc_free_statements (head);
  gfc_current_locus = old_loc;
  return m;
}


/* Match a single element of an IO list, which is either a single
   expression or an IO Iterator.  */

static match
match_io_element (io_kind k, gfc_code ** cpp)
{
  gfc_expr *expr;
  gfc_code *cp;
  match m;

  expr = NULL;

  m = match_io_iterator (k, cpp);
  if (m == MATCH_YES)
    return MATCH_YES;

  if (k == M_READ)
    {
      m = gfc_match_variable (&expr, 0);
      if (m == MATCH_NO)
	gfc_error ("Expected variable in READ statement at %C");
    }
  else
    {
      m = gfc_match_expr (&expr);
      if (m == MATCH_NO)
	gfc_error ("Expected expression in %s statement at %C",
		   io_kind_name (k));
    }

  if (m == MATCH_YES)
    switch (k)
      {
      case M_READ:
	if (expr->symtree->n.sym->attr.intent == INTENT_IN)
	  {
	    gfc_error
	      ("Variable '%s' in input list at %C cannot be INTENT(IN)",
	       expr->symtree->n.sym->name);
	    m = MATCH_ERROR;
	  }

	if (gfc_pure (NULL)
	    && gfc_impure_variable (expr->symtree->n.sym)
	    && current_dt->io_unit->ts.type == BT_CHARACTER)
	  {
	    gfc_error ("Cannot read to variable '%s' in PURE procedure at %C",
		       expr->symtree->n.sym->name);
	    m = MATCH_ERROR;
	  }

	if (gfc_check_do_variable (expr->symtree))
	  m = MATCH_ERROR;

	break;

      case M_WRITE:
	if (current_dt->io_unit->ts.type == BT_CHARACTER
	    && gfc_pure (NULL)
	    && current_dt->io_unit->expr_type == EXPR_VARIABLE
	    && gfc_impure_variable (current_dt->io_unit->symtree->n.sym))
	  {
	    gfc_error
	      ("Cannot write to internal file unit '%s' at %C inside a "
	       "PURE procedure", current_dt->io_unit->symtree->n.sym->name);
	    m = MATCH_ERROR;
	  }

	break;

      default:
	break;
      }