Correct backtrace generation in Carpet

[Erik Schnetter]

The file backtrace.cc in CarpetLib does not #include <cctk.h>; hence all HAVE_BACKTRACE* macros are undefined, and only basic backtraces are generated.

Correcting this is non-trivial, since the backtrace code is arcane, is written in C, probably expects glibc, contains (I'm fairly certain) memory allocation errors, and doesn't build e.g. on Mac OSX. The code also spends an inordinate amount of time allocating and freeing string buffers, which should be replaced by simply using C++ streams.

The backtrace code also probably requires a few more autoconf tests, so that it can be disabled where it does not work.

Keyword:

[Ian Hinder]

Given that backtraces are very useful, and used to work on "standard" linux systems, maybe the code could be enabled despite the problems that you mention. The memory allocation errors and buffers shouldn't be a problem since this only happens when the process is about to terminate due to the error anyway, right? Can we detect that we have glibc and Linux, and enable the backtrace code in that case? I know it's not as elegant as correctly autoconfing everything, but it's probably a lot easier. And having a backtrace with meaningful symbols is extremely useful.

[Roland Haas]

Replying to [comment:1 hinder]:

Given that backtraces are very useful, and used to work on "standard" linux systems, maybe the code could be enabled despite the problems that you mention. The memory allocation errors and buffers shouldn't be a problem since this only happens when the process is about to terminate due to the error anyway, right? Can we detect that we have glibc and Linux, and enable the backtrace code in that case? I know it's not as elegant as correctly autoconfing everything, but it's probably a lot easier. And having a backtrace with meaningful symbols is extremely useful.

I second that :-)

[Roland Haas]

ping.