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PR 53796 Improve INQUIRE(RECL=...) handling

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The current F2018 draft (N2137) specifies behavior of the RECL=
specifier in the INQUIRE statement, where it previously was left as
undefined. Namely:

- If the unit is not connected, RECL= should be given the value -1.
- If the unit is connected with stream access, RECL= should be given
  the value -2.

Further, as PR 53796 describes, the handling of RECL= is poor in other
ways as well. When the recl is set to the maximum possible
(GFC_INTEGER_8_HUGE / LLONG_MAX), which it does by default except for
preconnected units, and when INQUIRE(RECL=) is used with a 4 byte
integer, the value is truncated and the 4 byte value is thus
-1. Fixing this to generate an error is a lot of work, as currently
the truncation is done by the frontend, the library sees only an 8
byte value with no indication that the frontend is going to copy it to
a 4 byte one. Instead, this patch does a bit twiddling trick such that
the truncated 4 byte value is GFC_INTEGER_4_HUGE while still being
0.99999999 * GFC_INTEGER_8_HUGE which is large enough for all
practical purposes.

Finally, the patch removes GFORTRAN_DEFAULT_RECL which was used only
for preconnected units, and instead uses the same approach as describe
above.

Regtested on x86_64-pc-linux-gnu, Ok for trunk.

gcc/fortran/ChangeLog:

2017-11-28  Janne Blomqvist  <jb@gcc.gnu.org>

	PR fortran/53796
	* gfortran.texi: Remove mentions of GFORTRAN_DEFAULT_RECL.

libgfortran/ChangeLog:

2017-11-28  Janne Blomqvist  <jb@gcc.gnu.org>

	PR fortran/53796
	* io/inquire.c (inquire_via_unit): Set recl to -1 for unconnected
	units.
	* io/io.h (default_recl): New variable.
	* io/open.c (new_unit): Set recl to default_recl for sequential,
	-2 for stream access.
	* io/transfer.c (read_block_form): Test against default_recl
	instead of DEFAULT_RECL.
	(write_block): Likewise.
	* io/unit.c (init_units): Calculate max_offset, default_recl.
	* libgfortran.h (DEFAULT_RECL): Remove.
	* runtime/environ.c: Remove GFORTRAN_DEFAULT_RECL.

gcc/testsuite/ChangeLog:

2017-11-28  Janne Blomqvist  <jb@gcc.gnu.org>

	PR fortran/53796
	* gfortran.dg/inquire_recl_f2018.f90: New test.

From-SVN: r255215
This commit is contained in:
Janne Blomqvist 2017-11-28 21:28:50 +02:00
parent 6df8934f6a
commit 67c24a8bd6
11 changed files with 89 additions and 36 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

5
gcc/fortran/ChangeLog
View file

@ -1,3 +1,8 @@
2017-11-28 Janne Blomqvist <jb@gcc.gnu.org>
PR fortran/53796
* gfortran.texi: Remove mentions of GFORTRAN_DEFAULT_RECL.
2017-11-28 Paul Thomas <pault@gcc.gnu.org>
PR fortran/83021

9
gcc/fortran/gfortran.texi
View file

@ -600,7 +600,6 @@ Malformed environment variables are silently ignored.
* GFORTRAN_UNBUFFERED_PRECONNECTED:: Do not buffer I/O for preconnected units.
* GFORTRAN_SHOW_LOCUS:: Show location for runtime errors
* GFORTRAN_OPTIONAL_PLUS:: Print leading + where permitted
* GFORTRAN_DEFAULT_RECL:: Default record length for new files
* GFORTRAN_LIST_SEPARATOR:: Separator for list output
* GFORTRAN_CONVERT_UNIT:: Set endianness for unformatted I/O
* GFORTRAN_ERROR_BACKTRACE:: Show backtrace on run-time errors
@ -683,14 +682,6 @@ where permitted by the Fortran standard. If the first letter
is @samp{n}, @samp{N} or @samp{0}, a plus sign is not printed
in most cases. Default is not to print plus signs.
@node GFORTRAN_DEFAULT_RECL
@section @env{GFORTRAN_DEFAULT_RECL}---Default record length for new files
This environment variable specifies the default record length, in
bytes, for files which are opened without a @code{RECL} tag in the
@code{OPEN} statement. This must be a positive integer. The
default value is 1073741824 bytes (1 GB).
@node GFORTRAN_LIST_SEPARATOR
@section @env{GFORTRAN_LIST_SEPARATOR}---Separator for list output

5
gcc/testsuite/ChangeLog
View file

@ -1,3 +1,8 @@
2017-11-28 Janne Blomqvist <jb@gcc.gnu.org>
PR fortran/53796
* gfortran.dg/inquire_recl_f2018.f90: New test.
2017-11-28 Prathamesh Kulkarni <prathamesh.kulkarni@linaro.org>
Martin Jambor <mjambor@suse.cz>

42
gcc/testsuite/gfortran.dg/inquire_recl_f2018.f90 Normal file
View file

@ -0,0 +1,42 @@
! { dg-do run }
! PR 53796 INQUIRE(RECL=...)
program inqrecl
implicit none
integer(8) :: r
integer :: r4
! F2018 (N2137) 12.10.2.26: recl for unconnected should be -1
inquire(10, recl=r)
if (r /= -1) then
call abort()
end if
! Formatted sequential
open(10, status="scratch")
inquire(10, recl=r)
inquire(10, recl=r4)
close(10)
if (r /= huge(0_8) - huge(0_4) - 1) then
call abort()
end if
if (r4 /= huge(0)) then
call abort()
end if
! Formatted sequential with recl= specifier
open(10, status="scratch", recl=100)
inquire(10, recl=r)
close(10)
if (r /= 100) then
call abort()
end if
! Formatted stream
! F2018 (N2137) 12.10.2.26: If unit is connected
! for stream access, recl should be assigned the value -2.
open(10, status="scratch", access="stream")
inquire(10, recl=r)
close(10)
if (r /= -2) then
call abort()
end if
end program inqrecl

4
libgfortran/io/inquire.c
View file

@ -218,7 +218,9 @@ inquire_via_unit (st_parameter_inquire *iqp, gfc_unit *u)
}
if ((cf & IOPARM_INQUIRE_HAS_RECL_OUT) != 0)
*iqp->recl_out = (u != NULL) ? u->recl : 0;
/* F2018 (N2137) 12.10.2.26: If there is no connection, recl is
assigned the value -1. */
*iqp->recl_out = (u != NULL) ? u->recl : -1;
if ((cf & IOPARM_INQUIRE_HAS_STRM_POS_OUT) != 0)
*iqp->strm_pos_out = (u != NULL) ? u->strm_pos : 0;

5
libgfortran/io/io.h
View file

@ -735,6 +735,11 @@ gfc_saved_unit;
extern gfc_offset max_offset;
internal_proto(max_offset);
/* Default RECL for sequential access if not given in OPEN statement,
computed at library initialization time. */
extern gfc_offset default_recl;
internal_proto(default_recl);
/* Unit tree root. */
extern gfc_unit *unit_root;
internal_proto(unit_root);

6
libgfortran/io/open.c
View file

@ -586,7 +586,7 @@ new_unit (st_parameter_open *opp, gfc_unit *u, unit_flags *flags)
else
{
u->flags.has_recl = 0;
u->recl = max_offset;
u->recl = default_recl;
if (compile_options.max_subrecord_length)
{
u->recl_subrecord = compile_options.max_subrecord_length;
@ -622,7 +622,9 @@ new_unit (st_parameter_open *opp, gfc_unit *u, unit_flags *flags)
if (flags->access == ACCESS_STREAM)
{
u->maxrec = max_offset;
u->recl = 1;
/* F2018 (N2137) 12.10.2.26: If the connection is for stream
access recl is assigned the value -2. */
u->recl = -2;
u->bytes_left = 1;
u->strm_pos = stell (u->s) + 1;
}

4
libgfortran/io/transfer.c
View file

@ -451,7 +451,7 @@ read_block_form (st_parameter_dt *dtp, int *nbytes)
/* For preconnected units with default record length, set bytes left
to unit record length and proceed, otherwise error. */
if (dtp->u.p.current_unit->unit_number == options.stdin_unit
&& dtp->u.p.current_unit->recl == DEFAULT_RECL)
&& dtp->u.p.current_unit->recl == default_recl)
dtp->u.p.current_unit->bytes_left = dtp->u.p.current_unit->recl;
else
{
@ -757,7 +757,7 @@ write_block (st_parameter_dt *dtp, int length)
== options.stdout_unit
|| dtp->u.p.current_unit->unit_number
== options.stderr_unit)
&& dtp->u.p.current_unit->recl == DEFAULT_RECL))
&& dtp->u.p.current_unit->recl == default_recl))
dtp->u.p.current_unit->bytes_left = dtp->u.p.current_unit->recl;
else
{

33
libgfortran/io/unit.c
View file

@ -95,7 +95,10 @@ static int newunit_lwi;
#define CACHE_SIZE 3
static gfc_unit *unit_cache[CACHE_SIZE];
gfc_offset max_offset;
gfc_offset default_recl;
gfc_unit *unit_root;
#ifdef __GTHREAD_MUTEX_INIT
__gthread_mutex_t unit_lock = __GTHREAD_MUTEX_INIT;
@ -575,7 +578,6 @@ void
init_units (void)
{
gfc_unit *u;
unsigned int i;
#ifdef HAVE_NEWLOCALE
c_locale = newlocale (0, "C", 0);
@ -589,6 +591,22 @@ init_units (void)
__GTHREAD_MUTEX_INIT_FUNCTION (&unit_lock);
#endif
if (sizeof (max_offset) == 8)
{
max_offset = GFC_INTEGER_8_HUGE;
/* Why this weird value? Because if the recl specifier in the
inquire statement is a 4 byte value, u->recl is truncated,
and this trick ensures it becomes HUGE(0) rather than -1.
The full 8 byte value of default_recl is still 0.99999999 *
max_offset which is large enough for all practical
purposes. */
default_recl = max_offset & ~(1LL<<31);
}
else if (sizeof (max_offset) == 4)
max_offset = default_recl = GFC_INTEGER_4_HUGE;
else
internal_error (NULL, "sizeof (max_offset) must be 4 or 8");
if (options.stdin_unit >= 0)
{ /* STDIN */
u = insert_unit (options.stdin_unit);
@ -611,7 +629,7 @@ init_units (void)
u->flags.share = SHARE_UNSPECIFIED;
u->flags.cc = CC_LIST;
u->recl = options.default_recl;
u->recl = default_recl;
u->endfile = NO_ENDFILE;
u->filename = strdup (stdin_name);
@ -642,7 +660,7 @@ init_units (void)
u->flags.share = SHARE_UNSPECIFIED;
u->flags.cc = CC_LIST;
u->recl = options.default_recl;
u->recl = default_recl;
u->endfile = AT_ENDFILE;
u->filename = strdup (stdout_name);
@ -672,7 +690,7 @@ init_units (void)
u->flags.share = SHARE_UNSPECIFIED;
u->flags.cc = CC_LIST;
u->recl = options.default_recl;
u->recl = default_recl;
u->endfile = AT_ENDFILE;
u->filename = strdup (stderr_name);
@ -682,13 +700,6 @@ init_units (void)
__gthread_mutex_unlock (&u->lock);
}
/* Calculate the maximum file offset in a portable manner.
max will be the largest signed number for the type gfc_offset.
set a 1 in the LSB and keep a running sum, stopping at MSB-1 bit. */
max_offset = 0;
for (i = 0; i < sizeof (max_offset) * 8 - 1; i++)
max_offset = max_offset + ((gfc_offset) 1 << i);
}

8
libgfortran/libgfortran.h
View file

@ -511,7 +511,7 @@ typedef struct
int separator_len;
const char *separator;
int all_unbuffered, unbuffered_preconnected, default_recl;
int all_unbuffered, unbuffered_preconnected;
int fpe, backtrace;
}
options_t;
@ -577,12 +577,6 @@ extern char *filename;
iexport_data_proto(filename);
/* The default value of record length for preconnected units is defined
here. This value can be overriden by an environment variable.
Default value is 1 Gb. */
#define DEFAULT_RECL 1073741824
#define CHARACTER2(name) \
gfc_charlen_type name ## _len; \
char * name

4
libgfortran/runtime/environ.c
View file

@ -208,10 +208,6 @@ static variable variable_table[] = {
/* Print optional plus signs in numbers where permitted */
{ "GFORTRAN_OPTIONAL_PLUS", 0, &options.optional_plus, init_boolean },
/* Default maximum record length for sequential files */
{ "GFORTRAN_DEFAULT_RECL", DEFAULT_RECL, &options.default_recl,
init_unsigned_integer },
/* Separator to use when writing list output */
{ "GFORTRAN_LIST_SEPARATOR", 0, NULL, init_sep },