[patch, libgfortran] PR78351 comma not terminating READ of formatted input field

[Jerry DeLisle]

Hi all,

The attached patch adds code in read_sf_internal to handle early
termination of reads in the presence of comma's. This is to support
legacy codes which are not standard conforming as far as we can tell.

The additions are executed only if -std=legacy is given at compile time.
It does not support kind=4 internal units since in legacy years there
should be no kind=4 internal units.

I have provuded a simplified test case for various combinations of comma
embedded strings.

This has been regression tested on x86_64-pc-linux-gnu.

OK for trunk?

This use to work way back in early versions so should probably go to 7
and 8 branches. Opinions welcome.

Regards,

Jerry

2018-11-04 Jerry DeLisle <***@gcc.gnu.org>

* io/transfer.c (read_sf_internal): Add support for early
comma termination of internal unit formatted reads.

[Andreas Schwab]

+ /* To support legacy code we have to scan the input string one byte
+ at a time because we don't no where an early comma may be and the

s/no/know/

Andreas.

[Bernhard Reutner-Fischer]

On Sat, 3 Nov 2018 15:33:07 -0700

diff --git a/libgfortran/io/transfer.c b/libgfortran/io/transfer.c
index 31198a3cc39..0d26101cef0 100644
--- a/libgfortran/io/transfer.c
+++ b/libgfortran/io/transfer.c
@@ -260,22 +250,80 @@ read_sf_internal (st_parameter_dt *dtp, size_t *length)
sseek (dtp->u.p.current_unit->s, -1, SEEK_CUR);
}
- lorig = *length;
- if (is_char4_unit(dtp))
+ /* To support legacy code we have to scan the input string one byte
+ at a time because we don't no where an early comma may be and the

As Andreas said s/no/know/

+ requested length could go passed the end of a comma shortened

s/passed/past/

+ /* Get the first chracter of the string to establish the base

s/chracter/character/

+ /* Now we scan the rest and exit deal with an end-of-file

s/ exit// ?

[Jerry DeLisle]

Post by Bernhard Reutner-Fischer
On Sat, 3 Nov 2018 15:33:07 -0700

diff --git a/libgfortran/io/transfer.c b/libgfortran/io/transfer.c
index 31198a3cc39..0d26101cef0 100644
--- a/libgfortran/io/transfer.c
+++ b/libgfortran/io/transfer.c
@@ -260,22 +250,80 @@ read_sf_internal (st_parameter_dt *dtp, size_t *length)
sseek (dtp->u.p.current_unit->s, -1, SEEK_CUR);
}
- lorig = *length;
- if (is_char4_unit(dtp))
+ /* To support legacy code we have to scan the input string one byte
+ at a time because we don't no where an early comma may be and the

As Andreas said s/no/know/

+ requested length could go passed the end of a comma shortened

s/passed/past/

+ /* Get the first chracter of the string to establish the base

s/chracter/character/

+ /* Now we scan the rest and exit deal with an end-of-file

s/ exit// ?

Fixed all my typos, thanks.

Jerry

[Thomas Koenig]

Hi Jerry!

Post by Jerry DeLisle
Hi all,
The attached patch adds code in read_sf_internal to handle early
termination of reads in the presence of comma's. This is to support
legacy codes which are not standard conforming as far as we can tell.
The additions are executed only if -std=legacy is given at compile time.
 It does not support kind=4 internal units since in legacy years there
should be no kind=4 internal units.
I have provuded a simplified test case for various combinations of comma
embedded strings.
This has been regression tested on x86_64-pc-linux-gnu.
OK for trunk?

Yes, OK. I like the fact that the old, slow behavior is restricted
to -std=legacy :-)

Post by Jerry DeLisle
This use to work way back in early versions so should probably go to 7
and 8 branches. Opinions welcome.

I agree, it should go in.

Thanks a lot for the patch!

Regards

Thomas