io.c

gcc-fortran,linux使用fortran的编译软件。很好用的。

  switch (t)
    {

    case FMT_COMMA:
      goto format_item;

    case FMT_RPAREN:
      level--;
      if (level < 0)
	goto finished;
      goto between_desc;

    case FMT_COLON:
    case FMT_SLASH:
      goto optional_comma;

    case FMT_END:
      error = unexpected_end;
      goto syntax;

    default:
      if (gfc_notify_std (GFC_STD_GNU, "Extension: Missing comma at %C")
	  == FAILURE)
	return FAILURE;
      goto format_item_1;
    }

optional_comma:
  /* Optional comma is a weird between state where we've just finished
     reading a colon, slash or P descriptor.  */
  t = format_lex ();
  switch (t)
    {
    case FMT_COMMA:
      break;

    case FMT_RPAREN:
      level--;
      if (level < 0)
	goto finished;
      goto between_desc;

    default:
      /* Assume that we have another format item.  */
      saved_token = t;
      break;
    }

  goto format_item;

extension_optional_comma:
  /* As a GNU extension, permit a missing comma after a string literal.  */
  t = format_lex ();
  switch (t)
    {
    case FMT_COMMA:
      break;

    case FMT_RPAREN:
      level--;
      if (level < 0)
	goto finished;
      goto between_desc;

    case FMT_COLON:
    case FMT_SLASH:
      goto optional_comma;

    case FMT_END:
      error = unexpected_end;
      goto syntax;

    default:
      if (gfc_notify_std (GFC_STD_GNU, "Extension: Missing comma at %C")
	  == FAILURE)
	return FAILURE;
      saved_token = t;
      break;
    }

  goto format_item;

syntax:
  /* Something went wrong.  If the format we're checking is a string,
     generate a warning, since the program is correct.  If the format
     is in a FORMAT statement, this messes up parsing, which is an
     error.  */
  if (mode != MODE_STRING)
    gfc_error ("%s in format string at %C", error);
  else
    {
      gfc_warning ("%s in format string at %C", error);

      /* TODO: More elaborate measures are needed to show where a problem
         is within a format string that has been calculated.  */
    }

  rv = FAILURE;

finished:
  return rv;
}


/* Given an expression node that is a constant string, see if it looks
   like a format string.  */

static void
check_format_string (gfc_expr * e)
{

  mode = MODE_STRING;
  format_string = e->value.character.string;
  check_format ();
}


/************ Fortran 95 I/O statement matchers *************/

/* Match a FORMAT statement.  This amounts to actually parsing the
   format descriptors in order to correctly locate the end of the
   format string.  */

match
gfc_match_format (void)
{
  gfc_expr *e;
  locus start;

  if (gfc_current_ns->proc_name
	&& gfc_current_ns->proc_name->attr.flavor == FL_MODULE)
    {
      gfc_error ("Format statement in module main block at %C.");
      return MATCH_ERROR;
    }

  if (gfc_statement_label == NULL)
    {
      gfc_error ("Missing format label at %C");
      return MATCH_ERROR;
    }
  gfc_gobble_whitespace ();

  mode = MODE_FORMAT;
  format_length = 0;

  start = gfc_current_locus;

  if (check_format () == FAILURE)
    return MATCH_ERROR;

  if (gfc_match_eos () != MATCH_YES)
    {
      gfc_syntax_error (ST_FORMAT);
      return MATCH_ERROR;
    }

  /* The label doesn't get created until after the statement is done
     being matched, so we have to leave the string for later.  */

  gfc_current_locus = start;	/* Back to the beginning */

  new_st.loc = start;
  new_st.op = EXEC_NOP;

  e = gfc_get_expr();
  e->expr_type = EXPR_CONSTANT;
  e->ts.type = BT_CHARACTER;
  e->ts.kind = gfc_default_character_kind;
  e->where = start;
  e->value.character.string = format_string = gfc_getmem(format_length+1);
  e->value.character.length = format_length;
  gfc_statement_label->format = e;

  mode = MODE_COPY;
  check_format ();		/* Guaranteed to succeed */
  gfc_match_eos ();		/* Guaranteed to succeed */

  return MATCH_YES;
}


/* Match an expression I/O tag of some sort.  */

static match
match_etag (const io_tag * tag, gfc_expr ** v)
{
  gfc_expr *result;
  match m;

  m = gfc_match (tag->spec, &result);
  if (m != MATCH_YES)
    return m;

  if (*v != NULL)
    {
      gfc_error ("Duplicate %s specification at %C", tag->name);
      gfc_free_expr (result);
      return MATCH_ERROR;
    }

  *v = result;
  return MATCH_YES;
}


/* Match a variable I/O tag of some sort.  */

static match
match_vtag (const io_tag * tag, gfc_expr ** v)
{
  gfc_expr *result;
  match m;

  m = gfc_match (tag->spec, &result);
  if (m != MATCH_YES)
    return m;

  if (*v != NULL)
    {
      gfc_error ("Duplicate %s specification at %C", tag->name);
      gfc_free_expr (result);
      return MATCH_ERROR;
    }

  if (result->symtree->n.sym->attr.intent == INTENT_IN)
    {
      gfc_error ("Variable tag cannot be INTENT(IN) at %C");
      gfc_free_expr (result);
      return MATCH_ERROR;
    }

  if (gfc_pure (NULL) && gfc_impure_variable (result->symtree->n.sym))
    {
      gfc_error ("Variable tag cannot be assigned in PURE procedure at %C");
      gfc_free_expr (result);
      return MATCH_ERROR;
    }

  *v = result;
  return MATCH_YES;
}


/* Match I/O tags that cause variables to become redefined.  */

static match
match_out_tag(const io_tag *tag, gfc_expr **result)
{
  match m;

  m = match_vtag(tag, result);
  if (m == MATCH_YES)
    gfc_check_do_variable((*result)->symtree);

  return m;
}


/* Match a label I/O tag.  */

static match
match_ltag (const io_tag * tag, gfc_st_label ** label)
{
  match m;
  gfc_st_label *old;

  old = *label;
  m = gfc_match (tag->spec, label);
  if (m == MATCH_YES && old != 0)
    {
      gfc_error ("Duplicate %s label specification at %C", tag->name);
      return MATCH_ERROR;
    }

  return m;
}


/* Do expression resolution and type-checking on an expression tag.  */

static try
resolve_tag (const io_tag * tag, gfc_expr * e)
{

  if (e == NULL)
    return SUCCESS;

  if (gfc_resolve_expr (e) == FAILURE)
    return FAILURE;

  if (e->ts.type != tag->type && tag != &tag_format)
    {
      gfc_error ("%s tag at %L must be of type %s", tag->name,
		&e->where, gfc_basic_typename (tag->type));
      return FAILURE;
    }

  if (tag == &tag_format)
    {
      if (e->expr_type == EXPR_CONSTANT
	  && (e->ts.type != BT_CHARACTER
	      || e->ts.kind != gfc_default_character_kind))
	{
	  gfc_error ("Constant expression in FORMAT tag at %L must be "
		     "of type default CHARACTER", &e->where);
	  return FAILURE;
	}

      /* If e's rank is zero and e is not an element of an array, it should be
	 of integer or character type.  The integer variable should be
	 ASSIGNED.  */
      if (e->symtree == NULL || e->symtree->n.sym->as == NULL
		|| e->symtree->n.sym->as->rank == 0)
	{
	  if (e->ts.type != BT_CHARACTER && e->ts.type != BT_INTEGER)
	    {
	      gfc_error ("%s tag at %L must be of type %s or %s", tag->name,
			&e->where, gfc_basic_typename (BT_CHARACTER),
			gfc_basic_typename (BT_INTEGER));
	      return FAILURE;
	    }
	  else if (e->ts.type == BT_INTEGER && e->expr_type == EXPR_VARIABLE)
	    {
	      if (gfc_notify_std (GFC_STD_F95_DEL,
			"Obsolete: ASSIGNED variable in FORMAT tag at %L",
			&e->where) == FAILURE)
		return FAILURE;
	      if (e->symtree->n.sym->attr.assign != 1)
		{
		  gfc_error ("Variable '%s' at %L has not been assigned a "
			"format label", e->symtree->n.sym->name, &e->where);
		  return FAILURE;
		}
	    }
	  return SUCCESS;
	}
      else
	{
	  /* if rank is nonzero, we allow the type to be character under
	     GFC_STD_GNU and other type under GFC_STD_LEGACY. It may be
	     assigned an Hollerith constant.  */
	  if (e->ts.type == BT_CHARACTER)
	    {
	      if (gfc_notify_std (GFC_STD_GNU,
			"Extension: Character array in FORMAT tag at %L",
			&e->where) == FAILURE)
		return FAILURE;
	    }
	  else
	    {
	      if (gfc_notify_std (GFC_STD_LEGACY,
			"Extension: Non-character in FORMAT tag at %L",
			&e->where) == FAILURE)
		return FAILURE;
	    }
	  return SUCCESS;
	}
    }
  else
    {
      if (e->rank != 0)
	{
	  gfc_error ("%s tag at %L must be scalar", tag->name, &e->where);
	  return FAILURE;
	}

      if (tag == &tag_iomsg)
	{
	  if (gfc_notify_std (GFC_STD_F2003, "Fortran 2003: IOMSG tag at %L",
			      &e->where) == FAILURE)
	    return FAILURE;
	}

      if (tag == &tag_iostat && e->ts.kind != gfc_default_integer_kind)
	{
	  if (gfc_notify_std (GFC_STD_GNU, "Fortran 95 requires default "
			      "INTEGER in IOSTAT tag at %L",
			      &e->where) == FAILURE)
	    return FAILURE;
	}

      if (tag == &tag_size && e->ts.kind != gfc_default_integer_kind)
	{
	  if (gfc_notify_std (GFC_STD_GNU, "Fortran 95 requires default "
			      "INTEGER in SIZE tag at %L",
			      &e->where) == FAILURE)
	    return FAILURE;
	}

      if (tag == &tag_convert)
	{
	  if (gfc_notify_std (GFC_STD_GNU, "Extension: CONVERT tag at %L",
			      &e->where) == FAILURE)
	    return FAILURE;
	}
    }
  return SUCCESS;
}


/* Match a single tag of an OPEN statement.  */

static match
match_open_element (gfc_open * open)
{
  match m;

  m = match_etag (&tag_unit, &open->unit);
  if (m != MATCH_NO)
    return m;
  m = match_out_tag (&tag_iomsg, &open->iomsg);
  if (m != MATCH_NO)
    return m;
  m = match_out_tag (&tag_iostat, &open->iostat);
  if (m != MATCH_NO)
    return m;
  m = match_etag (&tag_file, &open->file);
  if (m != MATCH_NO)
    return m;
  m = match_etag (&tag_status, &open->status);
  if (m != MATCH_NO)
    return m;
  m = match_etag (&tag_e_access, &open->access);
  if (m != MATCH_NO)
    return m;
  m = match_etag (&tag_e_form, &open->form);
  if (m != MATCH_NO)
    return m;
  m = match_etag (&tag_e_recl, &open->recl);
  if (m != MATCH_NO)
    return m;
  m = match_etag (&tag_e_blank, &open->blank);
  if (m != MATCH_NO)
    return m;
  m = match_etag (&tag_e_position, &open->position);
  if (m != MATCH_NO)
    return m;
  m = match_etag (&tag_e_action, &open->action);
  if (m != MATCH_NO)
    return m;
  m = match_etag (&tag_e_delim, &open->delim);
  if (m != MATCH_NO)
    return m;
  m = match_etag (&tag_e_pad, &open->pad);
  if (m != MATCH_NO)
    return m;
  m = match_ltag (&tag_err, &open->err);
  if (m != MATCH_NO)
    return m;
  m = match_etag (&tag_convert, &open->convert);
  if (m != MATCH_NO)
    return m;

  return MATCH_NO;
}


/* Free the gfc_open structure and all the expressions it contains.  */

void
gfc_free_open (gfc_open * open)
{

  if (open == NULL)
    return;

  gfc_free_expr (open->unit);
  gfc_free_expr (open->iomsg);
  gfc_free_expr (open->iostat);
  gfc_free_expr (open->file);
  gfc_free_expr (open->status);
  gfc_free_expr (open->access);
  gfc_free_expr (open->form);
  gfc_free_expr (open->recl);
  gfc_free_expr (open->blank);
  gfc_free_expr (open->position);
  gfc_free_expr (open->action);
  gfc_free_expr (open->delim);
  gfc_free_expr (open->pad);
  gfc_free_expr (open->convert);

  gfc_free (open);
}


/* Resolve everything in a gfc_open structure.  */

try
gfc_resolve_open (gfc_open * open)
{

  RESOLVE_TAG (&tag_unit, open->unit);
  RESOLVE_TAG (&tag_iomsg, open->iomsg);
  RESOLVE_TAG (&tag_iostat, open->iostat);
  RESOLVE_TAG (&tag_file, open->file);
  RESOLVE_TAG (&tag_status, open->status);
  RESOLVE_TAG (&tag_e_access, open->access);
  RESOLVE_TAG (&tag_e_form, open->form);
  RESOLVE_TAG (&tag_e_recl, open->recl);

  RESOLVE_TAG (&tag_e_blank, open->blank);
  RESOLVE_TAG (&tag_e_position, open->position);
  RESOLVE_TAG (&tag_e_action, open->action);
  RESOLVE_TAG (&tag_e_delim, open->delim);
  RESOLVE_TAG (&tag_e_pad, open->pad);
  RESOLVE_TAG (&tag_convert, open->convert);

  if (gfc_reference_st_label (open->err, ST_LABEL_TARGET) == FAILURE)
    return FAILURE;

  return SUCCESS;
}


/* Match an OPEN statement.  */

match
gfc_match_open (void)
{
  gfc_open *open;
  match m;

  m = gfc_match_char ('(');
  if (m == MATCH_NO)
    return m;

  open = gfc_getmem (sizeof (gfc_open));

  m = match_open_element (open);

  if (m == MATCH_ERROR)
    goto cleanup;
  if (m == MATCH_NO)
    {
      m = gfc_match_expr (&open->unit);
      if (m == MATCH_NO)
	goto syntax;
      if (m == MATCH_ERROR)
	goto cleanup;
    }

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

      m = match_open_element (open);
      if (m == MATCH_ERROR)
	goto cleanup;
      if (m == MATCH_NO)
	goto syntax;
    }

  if (gfc_match_eos () == MATCH_NO)
    goto syntax;

  if (gfc_pure (NULL))
    {
      gfc_error ("OPEN statement not allowed in PURE procedure at %C");
      goto cleanup;
    }

  new_st.op = EXEC_OPEN;
  new_st.ext.open = open;
  return MATCH_YES;

syntax:
  gfc_syntax_error (ST_OPEN);

cleanup:
  gfc_free_open (open);
  return MATCH_ERROR;
}


/* Free a gfc_close structure an all its expressions.  */

void
gfc_free_close (gfc_close * close)
{

  if (close == NULL)
    return;

  gfc_free_expr (close->unit);
  gfc_free_expr (close->iomsg);
  gfc_free_expr (close->iostat);
  gfc_free_expr (close->status);

  gfc_free (close);
}


/* Match elements of a CLOSE statement.  */

static match
match_close_element (gfc_close * close)
{
  match m;

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

  return MATCH_NO;
}


/* Match a CLOSE statement.  */

match
gfc_match_close (void)
{
  gfc_close *close;
  match m;

  m = gfc_match_char ('(');
  if (m == MATCH_NO)
    return m;

  close = gfc_getmem (sizeof (gfc_close));

  m = match_close_element (close);

  if (m == MATCH_ERROR)
    goto cleanup;
  if (m == MATCH_NO)
    {
      m = gfc_match_expr (&close->unit);
      if (m == MATCH_NO)
	goto syntax;
      if (m == MATCH_ERROR)
	goto cleanup;
    }

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

      m = match_close_element (close);
      if (m == MATCH_ERROR)
	goto cleanup;
      if (m == MATCH_NO)
	goto syntax;
    }

  if (gfc_match_eos () == MATCH_NO)
    goto syntax;

  if (gfc_pure (NULL))
    {
      gfc_error ("CLOSE statement not allowed in PURE procedure at %C");
      goto cleanup;
    }

  new_st.op = EXEC_CLOSE;
  new_st.ext.close = close;
  return MATCH_YES;

syntax:
  gfc_syntax_error (ST_CLOSE);

cleanup:
  gfc_free_close (close);
  return MATCH_ERROR;
}


/* Resolve everything in a gfc_close structure.  */

try
gfc_resolve_close (gfc_close * close)
{

  RESOLVE_TAG (&tag_unit, close->unit);
  RESOLVE_TAG (&tag_iomsg, close->iomsg);
  RESOLVE_TAG (&tag_iostat, close->iostat);
  RESOLVE_TAG (&tag_status, close->status);

  if (gfc_reference_st_label (close->err, ST_LABEL_TARGET) == FAILURE)
    return FAILURE;