trans-io.c

/* IO Code translation/library interface
   Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
   Contributed by Paul Brook

This file is part of GCC.

GCC 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, or (at your option) any later
version.

GCC 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 GCC; see the file COPYING.  If not, write to the Free
Software Foundation, 59 Temple Place - Suite 330, Boston, MA
02111-1307, USA.  */


#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tree.h"
#include "tree-gimple.h"
#include "ggc.h"
#include "toplev.h"
#include "real.h"
#include "gfortran.h"
#include "trans.h"
#include "trans-stmt.h"
#include "trans-array.h"
#include "trans-types.h"
#include "trans-const.h"


/* Members of the ioparm structure.  */

static GTY(()) tree ioparm_unit;
static GTY(()) tree ioparm_err;
static GTY(()) tree ioparm_end;
static GTY(()) tree ioparm_eor;
static GTY(()) tree ioparm_list_format;
static GTY(()) tree ioparm_library_return;
static GTY(()) tree ioparm_iostat;
static GTY(()) tree ioparm_exist;
static GTY(()) tree ioparm_opened;
static GTY(()) tree ioparm_number;
static GTY(()) tree ioparm_named;
static GTY(()) tree ioparm_rec;
static GTY(()) tree ioparm_nextrec;
static GTY(()) tree ioparm_size;
static GTY(()) tree ioparm_recl_in;
static GTY(()) tree ioparm_recl_out;
static GTY(()) tree ioparm_iolength;
static GTY(()) tree ioparm_file;
static GTY(()) tree ioparm_file_len;
static GTY(()) tree ioparm_status;
static GTY(()) tree ioparm_status_len;
static GTY(()) tree ioparm_access;
static GTY(()) tree ioparm_access_len;
static GTY(()) tree ioparm_form;
static GTY(()) tree ioparm_form_len;
static GTY(()) tree ioparm_blank;
static GTY(()) tree ioparm_blank_len;
static GTY(()) tree ioparm_position;
static GTY(()) tree ioparm_position_len;
static GTY(()) tree ioparm_action;
static GTY(()) tree ioparm_action_len;
static GTY(()) tree ioparm_delim;
static GTY(()) tree ioparm_delim_len;
static GTY(()) tree ioparm_pad;
static GTY(()) tree ioparm_pad_len;
static GTY(()) tree ioparm_format;
static GTY(()) tree ioparm_format_len;
static GTY(()) tree ioparm_advance;
static GTY(()) tree ioparm_advance_len;
static GTY(()) tree ioparm_name;
static GTY(()) tree ioparm_name_len;
static GTY(()) tree ioparm_internal_unit;
static GTY(()) tree ioparm_internal_unit_len;
static GTY(()) tree ioparm_sequential;
static GTY(()) tree ioparm_sequential_len;
static GTY(()) tree ioparm_direct;
static GTY(()) tree ioparm_direct_len;
static GTY(()) tree ioparm_formatted;
static GTY(()) tree ioparm_formatted_len;
static GTY(()) tree ioparm_unformatted;
static GTY(()) tree ioparm_unformatted_len;
static GTY(()) tree ioparm_read;
static GTY(()) tree ioparm_read_len;
static GTY(()) tree ioparm_write;
static GTY(()) tree ioparm_write_len;
static GTY(()) tree ioparm_readwrite;
static GTY(()) tree ioparm_readwrite_len;
static GTY(()) tree ioparm_namelist_name;
static GTY(()) tree ioparm_namelist_name_len;
static GTY(()) tree ioparm_namelist_read_mode;

/* The global I/O variables */

static GTY(()) tree ioparm_var;
static GTY(()) tree locus_file;
static GTY(()) tree locus_line;


/* Library I/O subroutines */

static GTY(()) tree iocall_read;
static GTY(()) tree iocall_read_done;
static GTY(()) tree iocall_write;
static GTY(()) tree iocall_write_done;
static GTY(()) tree iocall_x_integer;
static GTY(()) tree iocall_x_logical;
static GTY(()) tree iocall_x_character;
static GTY(()) tree iocall_x_real;
static GTY(()) tree iocall_x_complex;
static GTY(()) tree iocall_open;
static GTY(()) tree iocall_close;
static GTY(()) tree iocall_inquire;
static GTY(()) tree iocall_iolength;
static GTY(()) tree iocall_iolength_done;
static GTY(()) tree iocall_rewind;
static GTY(()) tree iocall_backspace;
static GTY(()) tree iocall_endfile;
static GTY(()) tree iocall_set_nml_val_int;
static GTY(()) tree iocall_set_nml_val_float;
static GTY(()) tree iocall_set_nml_val_char;
static GTY(()) tree iocall_set_nml_val_complex;
static GTY(()) tree iocall_set_nml_val_log;

/* Variable for keeping track of what the last data transfer statement
   was.  Used for deciding which subroutine to call when the data
   transfer is complete.  */
static enum { READ, WRITE, IOLENGTH } last_dt;

#define ADD_FIELD(name, type)						\
  ioparm_ ## name = gfc_add_field_to_struct				\
        (&(TYPE_FIELDS (ioparm_type)), ioparm_type,			\
	 get_identifier (stringize(name)), type)

#define ADD_STRING(name) \
  ioparm_ ## name = gfc_add_field_to_struct				\
        (&(TYPE_FIELDS (ioparm_type)), ioparm_type,			\
	 get_identifier (stringize(name)), pchar_type_node);		\
  ioparm_ ## name ## _len = gfc_add_field_to_struct			\
        (&(TYPE_FIELDS (ioparm_type)), ioparm_type,			\
	 get_identifier (stringize(name) "_len"), gfc_int4_type_node)


/* Create function decls for IO library functions.  */

void
gfc_build_io_library_fndecls (void)
{
  tree gfc_int4_type_node;
  tree gfc_pint4_type_node;
  tree ioparm_type;

  gfc_int4_type_node = gfc_get_int_type (4);
  gfc_pint4_type_node = build_pointer_type (gfc_int4_type_node);

  /* Build the st_parameter structure.  Information associated with I/O
     calls are transferred here.  This must match the one defined in the
     library exactly.  */

  ioparm_type = make_node (RECORD_TYPE);
  TYPE_NAME (ioparm_type) = get_identifier ("_gfc_ioparm");

  ADD_FIELD (unit, gfc_int4_type_node);
  ADD_FIELD (err, gfc_int4_type_node);
  ADD_FIELD (end, gfc_int4_type_node);
  ADD_FIELD (eor, gfc_int4_type_node);
  ADD_FIELD (list_format, gfc_int4_type_node);
  ADD_FIELD (library_return, gfc_int4_type_node);

  ADD_FIELD (iostat, gfc_pint4_type_node);
  ADD_FIELD (exist, gfc_pint4_type_node);
  ADD_FIELD (opened, gfc_pint4_type_node);
  ADD_FIELD (number, gfc_pint4_type_node);
  ADD_FIELD (named, gfc_pint4_type_node);
  ADD_FIELD (rec, gfc_pint4_type_node);
  ADD_FIELD (nextrec, gfc_pint4_type_node);
  ADD_FIELD (size, gfc_pint4_type_node);

  ADD_FIELD (recl_in, gfc_pint4_type_node);
  ADD_FIELD (recl_out, gfc_pint4_type_node);

  ADD_FIELD (iolength, gfc_pint4_type_node);

  ADD_STRING (file);
  ADD_STRING (status);

  ADD_STRING (access);
  ADD_STRING (form);
  ADD_STRING (blank);
  ADD_STRING (position);
  ADD_STRING (action);
  ADD_STRING (delim);
  ADD_STRING (pad);
  ADD_STRING (format);
  ADD_STRING (advance);
  ADD_STRING (name);
  ADD_STRING (internal_unit);
  ADD_STRING (sequential);

  ADD_STRING (direct);
  ADD_STRING (formatted);
  ADD_STRING (unformatted);
  ADD_STRING (read);
  ADD_STRING (write);
  ADD_STRING (readwrite);

  ADD_STRING (namelist_name);
  ADD_FIELD (namelist_read_mode, gfc_int4_type_node);

  gfc_finish_type (ioparm_type);

  ioparm_var = build_decl (VAR_DECL, get_identifier (PREFIX("ioparm")),
			   ioparm_type);
  DECL_EXTERNAL (ioparm_var) = 1;
  TREE_PUBLIC (ioparm_var) = 1;

  locus_line = build_decl (VAR_DECL, get_identifier (PREFIX("line")),
			   gfc_int4_type_node);
  DECL_EXTERNAL (locus_line) = 1;
  TREE_PUBLIC (locus_line) = 1;

  locus_file = build_decl (VAR_DECL, get_identifier (PREFIX("filename")),
			   pchar_type_node);
  DECL_EXTERNAL (locus_file) = 1;
  TREE_PUBLIC (locus_file) = 1;

  /* Define the transfer functions.  */

  iocall_x_integer =
    gfc_build_library_function_decl (get_identifier
				     (PREFIX("transfer_integer")),
				     void_type_node, 2, pvoid_type_node,
				     gfc_int4_type_node);

  iocall_x_logical =
    gfc_build_library_function_decl (get_identifier
				     (PREFIX("transfer_logical")),
				     void_type_node, 2, pvoid_type_node,
				     gfc_int4_type_node);

  iocall_x_character =
    gfc_build_library_function_decl (get_identifier
				     (PREFIX("transfer_character")),
				     void_type_node, 2, pvoid_type_node,
				     gfc_int4_type_node);

  iocall_x_real =
    gfc_build_library_function_decl (get_identifier (PREFIX("transfer_real")),
				     void_type_node, 2,
				     pvoid_type_node, gfc_int4_type_node);

  iocall_x_complex =
    gfc_build_library_function_decl (get_identifier
				     (PREFIX("transfer_complex")),
				     void_type_node, 2, pvoid_type_node,
				     gfc_int4_type_node);

  /* Library entry points */

  iocall_read =
    gfc_build_library_function_decl (get_identifier (PREFIX("st_read")),
				     void_type_node, 0);

  iocall_write =
    gfc_build_library_function_decl (get_identifier (PREFIX("st_write")),
				     void_type_node, 0);
  iocall_open =
    gfc_build_library_function_decl (get_identifier (PREFIX("st_open")),
				     void_type_node, 0);

  iocall_close =
    gfc_build_library_function_decl (get_identifier (PREFIX("st_close")),
				     void_type_node, 0);

  iocall_inquire =
    gfc_build_library_function_decl (get_identifier (PREFIX("st_inquire")),
				     gfc_int4_type_node, 0);

  iocall_iolength =
    gfc_build_library_function_decl(get_identifier (PREFIX("st_iolength")),
				    void_type_node, 0);

  iocall_rewind =
    gfc_build_library_function_decl (get_identifier (PREFIX("st_rewind")),
				     gfc_int4_type_node, 0);

  iocall_backspace =
    gfc_build_library_function_decl (get_identifier (PREFIX("st_backspace")),
				     gfc_int4_type_node, 0);

  iocall_endfile =
    gfc_build_library_function_decl (get_identifier (PREFIX("st_endfile")),
				     gfc_int4_type_node, 0);
  /* Library helpers */

  iocall_read_done =
    gfc_build_library_function_decl (get_identifier (PREFIX("st_read_done")),
				     gfc_int4_type_node, 0);

  iocall_write_done =
    gfc_build_library_function_decl (get_identifier (PREFIX("st_write_done")),
				     gfc_int4_type_node, 0);

  iocall_iolength_done =
    gfc_build_library_function_decl (get_identifier (PREFIX("st_iolength_done")),
				     gfc_int4_type_node, 0);

  iocall_set_nml_val_int =
    gfc_build_library_function_decl (get_identifier (PREFIX("st_set_nml_var_int")),
                                     void_type_node, 4,
                                     pvoid_type_node, pvoid_type_node,
                                     gfc_int4_type_node,gfc_int4_type_node);

  iocall_set_nml_val_float =
    gfc_build_library_function_decl (get_identifier (PREFIX("st_set_nml_var_float")),
                                     void_type_node, 4,
                                     pvoid_type_node, pvoid_type_node,
                                     gfc_int4_type_node,gfc_int4_type_node);
  iocall_set_nml_val_char =
    gfc_build_library_function_decl (get_identifier (PREFIX("st_set_nml_var_char")),
                                     void_type_node, 5,
                                     pvoid_type_node, pvoid_type_node,
                                     gfc_int4_type_node, gfc_int4_type_node, 
                                     gfc_charlen_type_node);
  iocall_set_nml_val_complex =
    gfc_build_library_function_decl (get_identifier (PREFIX("st_set_nml_var_complex")),
                                     void_type_node, 4,
                                     pvoid_type_node, pvoid_type_node,
                                     gfc_int4_type_node,gfc_int4_type_node);
  iocall_set_nml_val_log =
    gfc_build_library_function_decl (get_identifier (PREFIX("st_set_nml_var_log")),
                                     void_type_node, 4,
                                     pvoid_type_node, pvoid_type_node,
                                     gfc_int4_type_node,gfc_int4_type_node);

}


/* Generate code to store an non-string I/O parameter into the
   ioparm structure.  This is a pass by value.  */

static void
set_parameter_value (stmtblock_t * block, tree var, gfc_expr * e)
{
  gfc_se se;
  tree tmp;

  gfc_init_se (&se, NULL);
  gfc_conv_expr_type (&se, e, TREE_TYPE (var));
  gfc_add_block_to_block (block, &se.pre);

  tmp = build3 (COMPONENT_REF, TREE_TYPE (var), ioparm_var, var, NULL_TREE);
  gfc_add_modify_expr (block, tmp, se.expr);
}


/* Generate code to store an non-string I/O parameter into the
   ioparm structure.  This is pass by reference.  */

static void
set_parameter_ref (stmtblock_t * block, tree var, gfc_expr * e)
{
  gfc_se se;
  tree tmp;

  gfc_init_se (&se, NULL);
  se.want_pointer = 1;

  gfc_conv_expr_type (&se, e, TREE_TYPE (var));
  gfc_add_block_to_block (block, &se.pre);

  tmp = build3 (COMPONENT_REF, TREE_TYPE (var), ioparm_var, var, NULL_TREE);
  gfc_add_modify_expr (block, tmp, se.expr);
}


/* Generate code to store a string and its length into the
   ioparm structure.  */

static void
set_string (stmtblock_t * block, stmtblock_t * postblock, tree var,
	    tree var_len, gfc_expr * e)
{
  gfc_se se;
  tree tmp;
  tree msg;
  tree io;
  tree len;

  gfc_init_se (&se, NULL);
  gfc_conv_expr (&se, e);

  io = build3 (COMPONENT_REF, TREE_TYPE (var), ioparm_var, var, NULL_TREE);
  len = build3 (COMPONENT_REF, TREE_TYPE (var_len), ioparm_var, var_len,
		NULL_TREE);

  /* Integer variable assigned a format label.  */
  if (e->ts.type == BT_INTEGER && e->symtree->n.sym->attr.assign == 1)
    {
      msg =
        gfc_build_cstring_const ("Assigned label is not a format label");
      tmp = GFC_DECL_STRING_LEN (se.expr);
      tmp = build2 (LE_EXPR, boolean_type_node,
		    tmp, convert (TREE_TYPE (tmp), integer_minus_one_node));
      gfc_trans_runtime_check (tmp, msg, &se.pre);
      gfc_add_modify_expr (&se.pre, io, GFC_DECL_ASSIGN_ADDR (se.expr));
      gfc_add_modify_expr (&se.pre, len, GFC_DECL_STRING_LEN (se.expr));
    }
  else
    {
      gfc_conv_string_parameter (&se);
      gfc_add_modify_expr (&se.pre, io, fold_convert (TREE_TYPE (io), se.expr));
      gfc_add_modify_expr (&se.pre, len, se.string_length);
    }

  gfc_add_block_to_block (block, &se.pre);
  gfc_add_block_to_block (postblock, &se.post);

}


/* Set a member of the ioparm structure to one.  */
static void
set_flag (stmtblock_t *block, tree var)
{
  tree tmp, type = TREE_TYPE (var);

  tmp = build3 (COMPONENT_REF, type, ioparm_var, var, NULL_TREE);
  gfc_add_modify_expr (block, tmp, convert (type, integer_one_node));
}


/* Add a case to a IO-result switch.  */

static void
add_case (int label_value, gfc_st_label * label, stmtblock_t * body)
{
  tree tmp, value;

  if (label == NULL)
    return;			/* No label, no case */

  value = build_int_cst (NULL_TREE, label_value);

  /* Make a backend label for this case.  */
  tmp = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
  DECL_CONTEXT (tmp) = current_function_decl;

  /* And the case itself.  */
  tmp = build3_v (CASE_LABEL_EXPR, value, NULL_TREE, tmp);
  gfc_add_expr_to_block (body, tmp);

  /* Jump to the label.  */
  tmp = build1_v (GOTO_EXPR, gfc_get_label_decl (label));
  gfc_add_expr_to_block (body, tmp);
}


/* Generate a switch statement that branches to the correct I/O
   result label.  The last statement of an I/O call stores the
   result into a variable because there is often cleanup that
   must be done before the switch, so a temporary would have to
   be created anyway.  */

static void
io_result (stmtblock_t * block, gfc_st_label * err_label,
	   gfc_st_label * end_label, gfc_st_label * eor_label)
{
  stmtblock_t body;
  tree tmp, rc;

  /* If no labels are specified, ignore the result instead
     of building an empty switch.  */
  if (err_label == NULL
      && end_label == NULL
      && eor_label == NULL)
    return;

  /* Build a switch statement.  */
  gfc_start_block (&body);

  /* The label values here must be the same as the values
     in the library_return enum in the runtime library */
  add_case (1, err_label, &body);
  add_case (2, end_label, &body);
  add_case (3, eor_label, &body);

  tmp = gfc_finish_block (&body);

  rc = build3 (COMPONENT_REF, TREE_TYPE (ioparm_library_return), ioparm_var,
	       ioparm_library_return, NULL_TREE);

  tmp = build3_v (SWITCH_EXPR, rc, tmp, NULL_TREE);

  gfc_add_expr_to_block (block, tmp);
}


/* Store the current file and line number to variables so that if a
   library call goes awry, we can tell the user where the problem is.  */

static void
set_error_locus (stmtblock_t * block, locus * where)
{
  gfc_file *f;
  tree tmp;
  int line;

  f = where->lb->file;
  tmp = gfc_build_cstring_const (f->filename);

  tmp = gfc_build_addr_expr (pchar_type_node, tmp);
  gfc_add_modify_expr (block, locus_file, tmp);

#ifdef USE_MAPPED_LOCATION
  line = LOCATION_LINE (where->lb->location);
#else
  line = where->lb->linenum;
#endif
  gfc_add_modify_expr (block, locus_line, build_int_cst (NULL_TREE, line));
}


/* Translate an OPEN statement.  */

tree
gfc_trans_open (gfc_code * code)
{
  stmtblock_t block, post_block;
  gfc_open *p;
  tree tmp;

  gfc_init_block (&block);
  gfc_init_block (&post_block);

  set_error_locus (&block, &code->loc);
  p = code->ext.open;

  if (p->unit)
    set_parameter_value (&block, ioparm_unit, p->unit);

  if (p->file)
    set_string (&block, &post_block, ioparm_file, ioparm_file_len, p->file);

  if (p->status)
    set_string (&block, &post_block, ioparm_status,
		ioparm_status_len, p->status);

  if (p->access)
    set_string (&block, &post_block, ioparm_access,
		ioparm_access_len, p->access);

  if (p->form)
    set_string (&block, &post_block, ioparm_form, ioparm_form_len, p->form);

  if (p->recl)
    set_parameter_value (&block, ioparm_recl_in, p->recl);

  if (p->blank)
    set_string (&block, &post_block, ioparm_blank, ioparm_blank_len,
		p->blank);

  if (p->position)
    set_string (&block, &post_block, ioparm_position,
		ioparm_position_len, p->position);

  if (p->action)
    set_string (&block, &post_block, ioparm_action,
		ioparm_action_len, p->action);

  if (p->delim)
    set_string (&block, &post_block, ioparm_delim, ioparm_delim_len,
		p->delim);

  if (p->pad)
    set_string (&block, &post_block, ioparm_pad, ioparm_pad_len, p->pad);

  if (p->iostat)
    set_parameter_ref (&block, ioparm_iostat, p->iostat);

  if (p->err)
    set_flag (&block, ioparm_err);

  tmp = gfc_build_function_call (iocall_open, NULL_TREE);
  gfc_add_expr_to_block (&block, tmp);

  gfc_add_block_to_block (&block, &post_block);

  io_result (&block, p->err, NULL, NULL);

  return gfc_finish_block (&block);
}


/* Translate a CLOSE statement.  */

tree
gfc_trans_close (gfc_code * code)
{
  stmtblock_t block, post_block;
  gfc_close *p;
  tree tmp;

  gfc_init_block (&block);
  gfc_init_block (&post_block);

  set_error_locus (&block, &code->loc);
  p = code->ext.close;

  if (p->unit)
    set_parameter_value (&block, ioparm_unit, p->unit);

  if (p->status)
    set_string (&block, &post_block, ioparm_status,
		ioparm_status_len, p->status);

  if (p->iostat)
    set_parameter_ref (&block, ioparm_iostat, p->iostat);

  if (p->err)
    set_flag (&block, ioparm_err);

  tmp = gfc_build_function_call (iocall_close, NULL_TREE);
  gfc_add_expr_to_block (&block, tmp);

  gfc_add_block_to_block (&block, &post_block);

  io_result (&block, p->err, NULL, NULL);

  return gfc_finish_block (&block);
}


/* Common subroutine for building a file positioning statement.  */

static tree
build_filepos (tree function, gfc_code * code)
{
  stmtblock_t block;
  gfc_filepos *p;
  tree tmp;

  p = code->ext.filepos;

  gfc_init_block (&block);

  set_error_locus (&block, &code->loc);

  if (p->unit)
    set_parameter_value (&block, ioparm_unit, p->unit);

  if (p->iostat)
    set_parameter_ref (&block, ioparm_iostat, p->iostat);

  if (p->err)
    set_flag (&block, ioparm_err);

  tmp = gfc_build_function_call (function, NULL);
  gfc_add_expr_to_block (&block, tmp);

  io_result (&block, p->err, NULL, NULL);

  return gfc_finish_block (&block);
}


/* Translate a BACKSPACE statement.  */

tree
gfc_trans_backspace (gfc_code * code)
{

  return build_filepos (iocall_backspace, code);
}


/* Translate an ENDFILE statement.  */

tree
gfc_trans_endfile (gfc_code * code)
{

  return build_filepos (iocall_endfile, code);
}


/* Translate a REWIND statement.  */

tree
gfc_trans_rewind (gfc_code * code)
{

  return build_filepos (iocall_rewind, code);
}


/* Translate the non-IOLENGTH form of an INQUIRE statement.  */

tree
gfc_trans_inquire (gfc_code * code)
{
  stmtblock_t block, post_block;
  gfc_inquire *p;
  tree tmp;

  gfc_init_block (&block);
  gfc_init_block (&post_block);

  set_error_locus (&block, &code->loc);
  p = code->ext.inquire;

  if (p->unit)
    set_parameter_value (&block, ioparm_unit, p->unit);

  if (p->file)
    set_string (&block, &post_block, ioparm_file, ioparm_file_len, p->file);

  if (p->iostat)
    set_parameter_ref (&block, ioparm_iostat, p->iostat);

  if (p->exist)
    set_parameter_ref (&block, ioparm_exist, p->exist);

  if (p->opened)
    set_parameter_ref (&block, ioparm_opened, p->opened);

  if (p->number)
    set_parameter_ref (&block, ioparm_number, p->number);

  if (p->named)
    set_parameter_ref (&block, ioparm_named, p->named);

  if (p->name)
    set_string (&block, &post_block, ioparm_name, ioparm_name_len, p->name);

  if (p->access)
    set_string (&block, &post_block, ioparm_access,
		ioparm_access_len, p->access);

  if (p->sequential)
    set_string (&block, &post_block, ioparm_sequential,
		ioparm_sequential_len, p->sequential);

  if (p->direct)
    set_string (&block, &post_block, ioparm_direct,
		ioparm_direct_len, p->direct);

  if (p->form)
    set_string (&block, &post_block, ioparm_form, ioparm_form_len, p->form);

  if (p->formatted)
    set_string (&block, &post_block, ioparm_formatted,
		ioparm_formatted_len, p->formatted);

  if (p->unformatted)
    set_string (&block, &post_block, ioparm_unformatted,
		ioparm_unformatted_len, p->unformatted);

  if (p->recl)
    set_parameter_ref (&block, ioparm_recl_out, p->recl);

  if (p->nextrec)
    set_parameter_ref (&block, ioparm_nextrec, p->nextrec);

  if (p->blank)
    set_string (&block, &post_block, ioparm_blank, ioparm_blank_len,
		p->blank);

  if (p->position)
    set_string (&block, &post_block, ioparm_position,
		ioparm_position_len, p->position);

  if (p->action)
    set_string (&block, &post_block, ioparm_action,
		ioparm_action_len, p->action);

  if (p->read)
    set_string (&block, &post_block, ioparm_read, ioparm_read_len, p->read);

  if (p->write)
    set_string (&block, &post_block, ioparm_write,
		ioparm_write_len, p->write);

  if (p->readwrite)
    set_string (&block, &post_block, ioparm_readwrite,
		ioparm_readwrite_len, p->readwrite);

  if (p->delim)
    set_string (&block, &post_block, ioparm_delim, ioparm_delim_len,
		p->delim);

  if (p->err)
    set_flag (&block, ioparm_err);

  tmp = gfc_build_function_call (iocall_inquire, NULL);
  gfc_add_expr_to_block (&block, tmp);

  gfc_add_block_to_block (&block, &post_block);

  io_result (&block, p->err, NULL, NULL);

  return gfc_finish_block (&block);
}


static gfc_expr *
gfc_new_nml_name_expr (char * name)
{
   gfc_expr * nml_name;
   nml_name = gfc_get_expr();
   nml_name->ref = NULL;
   nml_name->expr_type = EXPR_CONSTANT;
   nml_name->ts.kind = gfc_default_character_kind;
   nml_name->ts.type = BT_CHARACTER;
   nml_name->value.character.length = strlen(name);
   nml_name->value.character.string = name;

   return nml_name;
}

static gfc_expr *
get_new_var_expr(gfc_symbol * sym)
{
  gfc_expr * nml_var;

  nml_var = gfc_get_expr();
  nml_var->expr_type = EXPR_VARIABLE;
  nml_var->ts = sym->ts;
  if (sym->as)
    nml_var->rank = sym->as->rank;
  nml_var->symtree = (gfc_symtree *)gfc_getmem (sizeof (gfc_symtree));
  nml_var->symtree->n.sym = sym;
  nml_var->where = sym->declared_at;
  sym->attr.referenced = 1;

  return nml_var;
}

/* For a scalar variable STRING whose address is ADDR_EXPR, generate a
   call to iocall_set_nml_val.  For derived type variable, recursively
   generate calls to iocall_set_nml_val for each leaf field. The leafs
   have no names -- their STRING field is null, and are interpreted by
   the run-time library as having only the value, as in the example:

   &foo bzz=1,2,3,4,5/

   Note that the first output field appears after the name of the
   variable, not of the field name.  This causes a little complication
   documented below.  */

static void
transfer_namelist_element (stmtblock_t * block, gfc_typespec * ts, tree addr_expr, 
                           tree string, tree string_length)
{
  tree tmp, args, arg2;
  tree expr;

  gcc_assert (POINTER_TYPE_P (TREE_TYPE (addr_expr)));

  if (ts->type == BT_DERIVED)
    {
      gfc_component *c;
      expr = gfc_build_indirect_ref (addr_expr);

      for (c = ts->derived->components; c; c = c->next)
        {
          tree field = c->backend_decl;
          gcc_assert (field && TREE_CODE (field) == FIELD_DECL);
          tmp = build3 (COMPONENT_REF, TREE_TYPE (field), 
			expr, field, NULL_TREE);

          if (c->dimension)
            gfc_todo_error ("NAMELIST IO of array in derived type");
          if (!c->pointer)
            tmp = gfc_build_addr_expr (NULL, tmp);
          transfer_namelist_element (block, &c->ts, tmp, string, string_length);

          /* The first output field bears the name of the topmost
             derived type variable.  All other fields are anonymous
             and appear with nulls in their string and string_length
             fields.  After the first use, we set string and
             string_length to null.  */
          string = null_pointer_node;
          string_length = integer_zero_node;
        }

      return;
    }

  args = gfc_chainon_list (NULL_TREE, addr_expr);
  args = gfc_chainon_list (args, string);
  args = gfc_chainon_list (args, string_length);
  arg2 = build_int_cst (gfc_array_index_type, ts->kind);
  args = gfc_chainon_list (args,arg2);

  switch (ts->type)
    {
    case BT_INTEGER:
      tmp = gfc_build_function_call (iocall_set_nml_val_int, args);
      break;

    case BT_CHARACTER:
      expr = gfc_build_indirect_ref (addr_expr);
      gcc_assert (TREE_CODE (TREE_TYPE (expr)) == ARRAY_TYPE);
      args = gfc_chainon_list (args,
                               TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (expr))));
      tmp = gfc_build_function_call (iocall_set_nml_val_char, args);
      break;

    case BT_REAL:
      tmp = gfc_build_function_call (iocall_set_nml_val_float, args);
      break;

    case BT_LOGICAL:
      tmp = gfc_build_function_call (iocall_set_nml_val_log, args);
      break;

    case BT_COMPLEX:
      tmp = gfc_build_function_call (iocall_set_nml_val_complex, args);
      break;

    default :
      internal_error ("Bad namelist IO basetype (%d)", ts->type);
    }

  gfc_add_expr_to_block (block, tmp);
}

/* Create a data transfer statement.  Not all of the fields are valid
   for both reading and writing, but improper use has been filtered
   out by now.  */

static tree
build_dt (tree * function, gfc_code * code)
{
  stmtblock_t block, post_block;
  gfc_dt *dt;
  tree tmp;
  gfc_expr *nmlname, *nmlvar;
  gfc_namelist *nml;
  gfc_se se,se2;

  gfc_init_block (&block);
  gfc_init_block (&post_block);

  set_error_locus (&block, &code->loc);
  dt = code->ext.dt;

  gcc_assert (dt != NULL);

  if (dt->io_unit)
    {
      if (dt->io_unit->ts.type == BT_CHARACTER)
	{
	  set_string (&block, &post_block, ioparm_internal_unit,
		      ioparm_internal_unit_len, dt->io_unit);
	}
      else
	set_parameter_value (&block, ioparm_unit, dt->io_unit);
    }

  if (dt->rec)
    set_parameter_value (&block, ioparm_rec, dt->rec);

  if (dt->advance)
    set_string (&block, &post_block, ioparm_advance, ioparm_advance_len,
		dt->advance);

  if (dt->format_expr)
    set_string (&block, &post_block, ioparm_format, ioparm_format_len,
		dt->format_expr);

  if (dt->format_label)
    {
      if (dt->format_label == &format_asterisk)
	set_flag (&block, ioparm_list_format);
      else
        set_string (&block, &post_block, ioparm_format,
		    ioparm_format_len, dt->format_label->format);
    }

  if (dt->iostat)
    set_parameter_ref (&block, ioparm_iostat, dt->iostat);

  if (dt->size)
    set_parameter_ref (&block, ioparm_size, dt->size);

  if (dt->err)
    set_flag (&block, ioparm_err);

  if (dt->eor)
    set_flag(&block, ioparm_eor);

  if (dt->end)
    set_flag(&block, ioparm_end);

  if (dt->namelist)
    {
       if (dt->format_expr || dt->format_label)
          fatal_error("A format cannot be specified with a namelist");

       nmlname = gfc_new_nml_name_expr(dt->namelist->name);

       set_string (&block, &post_block, ioparm_namelist_name,
                ioparm_namelist_name_len, nmlname);

       if (last_dt == READ)
          set_flag (&block, ioparm_namelist_read_mode);

	for (nml = dt->namelist->namelist; nml; nml = nml->next)
	  {
	    gfc_init_se (&se, NULL);
	    gfc_init_se (&se2, NULL);
	    nmlvar = get_new_var_expr (nml->sym);
	    nmlname = gfc_new_nml_name_expr (nml->sym->name);
	    gfc_conv_expr_reference (&se2, nmlname);
	    gfc_conv_expr_reference (&se, nmlvar);
	    gfc_evaluate_now (se.expr, &se.pre); 

	    transfer_namelist_element (&block, &nml->sym->ts, se.expr,
				       se2.expr, se2.string_length);
	  }
    }

  tmp = gfc_build_function_call (*function, NULL_TREE);
  gfc_add_expr_to_block (&block, tmp);

  gfc_add_block_to_block (&block, &post_block);

  return gfc_finish_block (&block);
}


/* Translate the IOLENGTH form of an INQUIRE statement.  We treat
   this as a third sort of data transfer statement, except that
   lengths are summed instead of actually transfering any data.  */

tree
gfc_trans_iolength (gfc_code * code)
{
  stmtblock_t block;
  gfc_inquire *inq;
  tree dt;

  gfc_init_block (&block);

  set_error_locus (&block, &code->loc);

  inq = code->ext.inquire;

  /* First check that preconditions are met.  */
  gcc_assert (inq != NULL);
  gcc_assert (inq->iolength != NULL);

  /* Connect to the iolength variable.  */
  if (inq->iolength)
    set_parameter_ref (&block, ioparm_iolength, inq->iolength);

  /* Actual logic.  */
  last_dt = IOLENGTH;
  dt = build_dt(&iocall_iolength, code);

  gfc_add_expr_to_block (&block, dt);

  return gfc_finish_block (&block);
}


/* Translate a READ statement.  */

tree
gfc_trans_read (gfc_code * code)
{

  last_dt = READ;
  return build_dt (&iocall_read, code);
}


/* Translate a WRITE statement */

tree
gfc_trans_write (gfc_code * code)
{

  last_dt = WRITE;
  return build_dt (&iocall_write, code);
}


/* Finish a data transfer statement.  */

tree
gfc_trans_dt_end (gfc_code * code)
{
  tree function, tmp;
  stmtblock_t block;

  gfc_init_block (&block);

  switch (last_dt)
    {
    case READ:
      function = iocall_read_done;
      break;

    case WRITE:
      function = iocall_write_done;
      break;

    case IOLENGTH:
      function = iocall_iolength_done;
      break;

    default:
      gcc_unreachable ();
    }

  tmp = gfc_build_function_call (function, NULL);
  gfc_add_expr_to_block (&block, tmp);

  if (last_dt != IOLENGTH)
    {
      gcc_assert (code->ext.dt != NULL);
      io_result (&block, code->ext.dt->err,
		 code->ext.dt->end, code->ext.dt->eor);
    }

  return gfc_finish_block (&block);
}

static void
transfer_expr (gfc_se * se, gfc_typespec * ts, tree addr_expr);

/* Given an array field in a derived type variable, generate the code
   for the loop that iterates over array elements, and the code that
   accesses those array elements.  Use transfer_expr to generate code
   for transferring that element.  Because elements may also be
   derived types, transfer_expr and transfer_array_component are mutually
   recursive.  */

static tree
transfer_array_component (tree expr, gfc_component * cm)
{
  tree tmp;
  stmtblock_t body;
  stmtblock_t block;
  gfc_loopinfo loop;
  int n;
  gfc_ss *ss;
  gfc_se se;

  gfc_start_block (&block);
  gfc_init_se (&se, NULL);

  /* Create and initialize Scalarization Status.  Unlike in
     gfc_trans_transfer, we can't simply use gfc_walk_expr to take
     care of this task, because we don't have a gfc_expr at hand.
     Build one manually, as in gfc_trans_subarray_assign.  */

  ss = gfc_get_ss ();
  ss->type = GFC_SS_COMPONENT;
  ss->expr = NULL;
  ss->shape = gfc_get_shape (cm->as->rank);
  ss->next = gfc_ss_terminator;
  ss->data.info.dimen = cm->as->rank;
  ss->data.info.descriptor = expr;
  ss->data.info.data = gfc_conv_array_data (expr);
  ss->data.info.offset = gfc_conv_array_offset (expr);
  for (n = 0; n < cm->as->rank; n++)
    {
      ss->data.info.dim[n] = n;
      ss->data.info.start[n] = gfc_conv_array_lbound (expr, n);
      ss->data.info.stride[n] = gfc_index_one_node;

      mpz_init (ss->shape[n]);
      mpz_sub (ss->shape[n], cm->as->upper[n]->value.integer,
               cm->as->lower[n]->value.integer);
      mpz_add_ui (ss->shape[n], ss->shape[n], 1);
    }

  /* Once we got ss, we use scalarizer to create the loop.  */

  gfc_init_loopinfo (&loop);
  gfc_add_ss_to_loop (&loop, ss);
  gfc_conv_ss_startstride (&loop);
  gfc_conv_loop_setup (&loop);
  gfc_mark_ss_chain_used (ss, 1);
  gfc_start_scalarized_body (&loop, &body);

  gfc_copy_loopinfo_to_se (&se, &loop);
  se.ss = ss;

  /* gfc_conv_tmp_array_ref assumes that se.expr contains the array.  */
  se.expr = expr;
  gfc_conv_tmp_array_ref (&se);

  /* Now se.expr contains an element of the array.  Take the address and pass
     it to the IO routines.  */
  tmp = gfc_build_addr_expr (NULL, se.expr);
  transfer_expr (&se, &cm->ts, tmp);

  /* We are done now with the loop body.  Wrap up the scalarizer and
     return.  */

  gfc_add_block_to_block (&body, &se.pre);
  gfc_add_block_to_block (&body, &se.post);

  gfc_trans_scalarizing_loops (&loop, &body);

  gfc_add_block_to_block (&block, &loop.pre);
  gfc_add_block_to_block (&block, &loop.post);

  for (n = 0; n < cm->as->rank; n++)
    mpz_clear (ss->shape[n]);
  gfc_free (ss->shape);

  gfc_cleanup_loop (&loop);

  return gfc_finish_block (&block);
}

/* Generate the call for a scalar transfer node.  */

static void
transfer_expr (gfc_se * se, gfc_typespec * ts, tree addr_expr)
{
  tree args, tmp, function, arg2, field, expr;
  gfc_component *c;
  int kind;

  kind = ts->kind;
  function = NULL;
  arg2 = NULL;

  switch (ts->type)
    {
    case BT_INTEGER:
      arg2 = build_int_cst (NULL_TREE, kind);
      function = iocall_x_integer;
      break;

    case BT_REAL:
      arg2 = build_int_cst (NULL_TREE, kind);
      function = iocall_x_real;
      break;

    case BT_COMPLEX:
      arg2 = build_int_cst (NULL_TREE, kind);
      function = iocall_x_complex;
      break;

    case BT_LOGICAL:
      arg2 = build_int_cst (NULL_TREE, kind);
      function = iocall_x_logical;
      break;

    case BT_CHARACTER:
      if (se->string_length)
	arg2 = se->string_length;
      else
	{
	  tmp = gfc_build_indirect_ref (addr_expr);
	  gcc_assert (TREE_CODE (TREE_TYPE (tmp)) == ARRAY_TYPE);
	  arg2 = TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (tmp)));
	}
      function = iocall_x_character;
      break;

    case BT_DERIVED:
      /* Recurse into the elements of the derived type.  */
      expr = gfc_evaluate_now (addr_expr, &se->pre);
      expr = gfc_build_indirect_ref (expr);

      for (c = ts->derived->components; c; c = c->next)
	{
	  field = c->backend_decl;
	  gcc_assert (field && TREE_CODE (field) == FIELD_DECL);

	  tmp = build3 (COMPONENT_REF, TREE_TYPE (field), expr, field,
			NULL_TREE);

          if (c->dimension)
            {
              tmp = transfer_array_component (tmp, c);
              gfc_add_expr_to_block (&se->pre, tmp);
            }
          else
            {
              if (!c->pointer)
                tmp = gfc_build_addr_expr (NULL, tmp);
              transfer_expr (se, &c->ts, tmp);
            }
	}
      return;

    default:
      internal_error ("Bad IO basetype (%d)", ts->type);
    }

  args = gfc_chainon_list (NULL_TREE, addr_expr);
  args = gfc_chainon_list (args, arg2);

  tmp = gfc_build_function_call (function, args);
  gfc_add_expr_to_block (&se->pre, tmp);
  gfc_add_block_to_block (&se->pre, &se->post);

}


/* gfc_trans_transfer()-- Translate a TRANSFER code node */

tree
gfc_trans_transfer (gfc_code * code)
{
  stmtblock_t block, body;
  gfc_loopinfo loop;
  gfc_expr *expr;
  gfc_ss *ss;
  gfc_se se;
  tree tmp;

  gfc_start_block (&block);

  expr = code->expr;
  ss = gfc_walk_expr (expr);

  gfc_init_se (&se, NULL);

  if (ss == gfc_ss_terminator)
    gfc_init_block (&body);
  else
    {
      /* Initialize the scalarizer.  */
      gfc_init_loopinfo (&loop);
      gfc_add_ss_to_loop (&loop, ss);

      /* Initialize the loop.  */
      gfc_conv_ss_startstride (&loop);
      gfc_conv_loop_setup (&loop);

      /* The main loop body.  */
      gfc_mark_ss_chain_used (ss, 1);
      gfc_start_scalarized_body (&loop, &body);

      gfc_copy_loopinfo_to_se (&se, &loop);
      se.ss = ss;
    }

  gfc_conv_expr_reference (&se, expr);

  transfer_expr (&se, &expr->ts, se.expr);

  gfc_add_block_to_block (&body, &se.pre);
  gfc_add_block_to_block (&body, &se.post);

  if (se.ss == NULL)
    tmp = gfc_finish_block (&body);
  else
    {
      gcc_assert (se.ss == gfc_ss_terminator);
      gfc_trans_scalarizing_loops (&loop, &body);

      gfc_add_block_to_block (&loop.pre, &loop.post);
      tmp = gfc_finish_block (&loop.pre);
      gfc_cleanup_loop (&loop);
    }

  gfc_add_expr_to_block (&block, tmp);

  return gfc_finish_block (&block);
}

#include "gt-fortran-trans-io.h"