2016-09-23  Jerry DeLisle  <jvdelisle@gcc.gnu.org>

	PR libgfortran/48298
	* io/inquire.c (inquire_via_unit): Adjust error check for the
	two possible internal unit KINDs.
	* io/io.h: Adjust defines for is_internal_unit and
	is_char4_unit. (gfc_unit): Add internal unit data to structure.
	(get_internal_unit): Change declaration to set_internal_unit.
	(free_internal_unit): Change name to stash_internal_unit_number.
	(get_unique_unit_number): Adjust parameter argument.
	Define IOPARM_DT_HAS_UDTIO. (gfc_saved_unit): New structure.
	* io/list_read.c (next_char_internal): Use is_char4_unit.
	* io/open.c (st_open): Adjust call to get_unique_unit_number.
	* io/transfer.c (write_block): Use is_char4_unit.
	(data_transfer_init): Update check for unit numbers.
	(st_read_done): Free the various allocated memories used for the
	internal units and stash the negative unit number and pointer to unit
	structure to allow reuse. (st_write_done): Likewise stash the freed
	unit.
	* io/unit.c: Create a fixed size buffer of 16 gfc_saved_unit's to use
	as a stack to save newunit unit numbers and unit structure for reuse.
	(get_external_unit): Change name to get_gfc_unit to better
	reflect what it does. (find_unit): Change call to get_gfc_unit.
	(find_or_create_unit): Likewise. (get_internal_unit): Change
	name to set_internal_unit. Move internal unit from the dtp
	structure to the gfc_unit structure so that it can be passed to
	child I/O statements through the UNIT.
	(free_internal_unit): Change name to stash_internal_unit_number.
	Push the common.unit number onto the newunit stack, saving it
	for possible reuse later. (get_unit): Set the internal unit
	KIND. Use get_unique_unit_number to get a negative unit number
	for the internal unit. Use get_gfc_unit to get the unit structure
	and use set_internal_unit to initialize it.
	(init_units): Initialize the newunit stack.
	(get_unique_unit_number): Check the stack for an available unit
	number and use it. If none there get the next most negative
	number. (close_units): Free any unit structures pointed to from the save
	stack.

2016-09-23  Jerry DeLisle  <jvdelisle@gcc.gnu.org>

	PR fortran/48298
	* gfortran.h (gfc_dt): Add *udtio.
	* ioparm.def: Add bit IOPARM_dt_f2003 to align with library use of bit
	25. Add IOPARM_dt_dtio bit to common flags.
	* resolve.c (resolve_transfer): Set dt->udtio to expression.
	* io.c (gfc_match_inquire): Adjust error message for internal
	unit KIND.
	* libgfortran.h: Adjust defines for GFC_INTERNAL_UNIT4,
	GFC_INTERNAL_UNIT, and GFC_INVALID_UNIT.
	* trans-io.c (build_dt): Set common_unit to reflect the KIND of
	the internal unit. Set mask bit for presence of dt->udtio.

2016-09-23  Jerry DeLisle  <jvdelisle@gcc.gnu.org>

	PR fortran/48298
	* gfortran.dg/negative_unit_check.f90: Update test.
	* gfortran.dg/dtio_14.f90: New test.

From-SVN: r240456