[Bug fortran/53379] [4.7/4.8 Regression] No backtrace generated for array bounds violation

["burnus at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53379

--- Comment #3 from Tobias Burnus <burnus at gcc dot gnu.org> 2012-05-18 07:35:17 UTC ---
(In reply to comment #2)
> AFAICS, this is an intentional change in behavior. When I proposed making
> backtracing enabled by default, there was some objections to the initial patch
> on the grounds that the backtracing was too aggressive.

I wonder whether one should add a more aggressive version of backtrace (which
could be internally pass backtrace == 2), which covers this case. Ditto for
some environment flag.

I have to admit that the description of
http://gcc.gnu.org/onlinedocs/gfortran/GFORTRAN_005fERROR_005fBACKTRACE.html is
misleading. And the meaning and relation of it to
http://gcc.gnu.org/onlinedocs/gfortran/GFORTRAN_005fSHOW_005fLOCUS.html is also
unclear.


> FWIW, if it is decided to change this, one could also consider changing
> runtime_error() and internal_error() in the same way, though one would need to
> audit the usage in libgfortran so that we don't generate a backtrace for a
> "file not found" or similar "benign" error.

I agree that, at least by default, "file not found" shouldn't print a backtrace
- though one could still think of it with some aggressive backtrace
flag/environment variable.