http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51591
Tobias Burnus <burnus at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |jb at gcc dot gnu.org
--- Comment #1 from Tobias Burnus <burnus at gcc dot gnu.org> 2011-12-17
09:39:05 UTC ---
(In reply to comment #0)
> > cat testc.c
> int sleepc_ (unsigned int *sec)
This function is actually not used but gfortran's intrinsic "sleep". (The
Fortran program calls "sleep" instead of "sleepc".)
> Sometimes output looks OK:
> But more often there is some garbled text output:
> 0im `m5 <<<<----- What's this?
I can reproduce this - though for me the output is more often OK than garbled
(60% vs. 40% of the output of:
for((I=0;$I < 20; I++)); do ./a.out ; done
)
That's with GCC 4.6. In GCC 4.7, it works much more often (I have to run the
the line above about ~20 times, i.e. approx every 400th run it fails).
Additionally, in 4.7 I do not see garbled output but a segfault.
A backtrace of the core dump shows:
Program terminated with signal 11, Segmentation fault.
#0 _gfortrani_fbuf_flush (u=0x6055d0, mode=<optimized out>)
at /home/tob/projects/gcc-git/gcc/libgfortran/io/fbuf.c:166
166 if (u->fbuf->act > u->fbuf->pos && u->fbuf->pos > 0)
(gdb) bt
#1 0x00002b37379836bd in _gfortrani_next_record (dtp=0x2b373926dc50, done=1)
at /home/tob/projects/gcc-git/gcc/libgfortran/io/transfer.c:3397
#2 0x00002b3737983f79 in _gfortran_st_write_done (dtp=0x2b373926dc50)
at /home/tob/projects/gcc-git/gcc/libgfortran/io/transfer.c:3592
(gdb) p u->fbuf
$3 = (struct fbuf *) 0x7e7e7e7e7e7e7e7e
The value matches:
$ echo $MALLOC_PERTURB_
126
Thus, "fbuf" points to malloced memory, which has never been initialized.
> <Nice to see that the STOP 1 results in an exit code of 1, though - new F08
> feature.>
I think gfortran (like several other compilers) does so since years; new (since
4.6) is the support for constant character and integer expressions for (error)
stop.
