[Bug libf2c/11918] New: isatty does not call f_init

[Bug libf2c/11918] New: isatty does not call f_init

[nvwarr at hotmail dot com]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11918

           Summary: isatty does not call f_init
           Product: gcc
           Version: 3.2.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: libf2c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: nvwarr at hotmail dot com
                CC: gcc-bugs at gcc dot gnu dot org

When calling a fortran subroutine from a C program, using isatty on stdin gives
a segmentation fault:
#0  0x400db449 in fileno_unlocked () from /lib/i686/libc.so.6
#1  0x40040417 in G77_fnum_0 () from /usr/lib/libg2c.so.0
#2  0x400407c8 in G77_isatty_0 () from /usr/lib/libg2c.so.0

This does not occur if f_init is called either explicitly from the C program, or
implicitly by calling some function which calls f_init.

There are three ways to fix it:
1) modify the C program to call f_init explicitly.
2) add a dummy write statement to the fortran code to force it to call f_init
implicitly
3) add a line to libf2c/libU77/isatty_.c:
if (f__init != 1) f_init();

Perhaps this line should really be added to libf2c/libU77/fnum_.c?

Probably there is another bug involving fnum as well. It looks as though the
code doesn't check if
the unit is actually open, so calling isatty (and anything else which calls
fnum) with a unit which has
been closed (or never opened) will cause a segmentation fault in fileno_unlocked
rather than a useful error message, regardless of whether f_init has been called
or not.

[Bug libf2c/11918] isatty does not call f_init

[pinskia at gcc dot gnu dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11918


pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|normal                      |enhancement
   Target Milestone|3.4                         |---

[Bug libf2c/11918] isatty does not call f_init

[dhazeghi at yahoo dot com]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11918


dhazeghi at yahoo dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |WAITING


------- Additional Comments From dhazeghi at yahoo dot com  2003-08-24 22:59 -------
Hello, would you mind attaching a testcase to this report that demonstrates the problem you've 
encountered? Also, if you have the opportunity to test with a newer version of gcc, that'd be quite 
helpful. Thanks.

[Bug libf2c/11918] isatty does not call f_init

[nvwarr at hotmail dot com]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11918



------- Additional Comments From nvwarr at hotmail dot com  2003-09-10 06:22 -------
I originally reported this but to RedHat's bugzilla with a test case. It seems
that subject line was forwarded by someone but without the explanation. So I'm
cutting and pasting what I sent to RedHat...


Description of problem:
Using a main program in C and a subroutine in Fortran, where the Fortran
uses isatty without using any other Fortran I/O, results in a segmentation fault
at that point.

Inserting another Fortran I/O operation before the call to isatty works around
the problem. Alternatively, calling f_init explicitly from the C code before
calling the Fortran also works.

My problem occurs in a large complicated set of code mixing C and Fortran, but
the example below illustrates the problem.

Version-Release number of selected component (if applicable):
gcc-g77-3.2-7

[Bug libf2c/11918] isatty does not call f_init

[pinskia at gcc dot gnu dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11918


pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|WAITING                     |RESOLVED
         Resolution|                            |INVALID


------- Additional Comments From pinskia at gcc dot gnu dot org  2003-09-13 19:09 -------
Thats move this into a ...

[Bug libf2c/11918] isatty does not call f_init

[pinskia at gcc dot gnu dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11918


pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |UNCONFIRMED
         Resolution|INVALID                     |


------- Additional Comments From pinskia at gcc dot gnu dot org  2003-09-13 19:09 -------
virgin state.

[Bug libf2c/11918] isatty does not call f_init

[pinskia at gcc dot gnu dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11918


pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |FIXED


------- Additional Comments From pinskia at gcc dot gnu dot org  2003-09-21 16:43 -------
Fixed by:
	2003-09-21  Toon Moene  <toon@moene.indiv.nluug.nl>
	
	PR libf2c/11918
	* fstat_.c: Call f_init().
	* isatty_.c: Ditto.
	* fnum_.c: Check file descriptor before handing it back.

[Bug libf2c/11918] isatty does not call f_init

[dhazeghi at yahoo dot com]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |3.4


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11918