build: improve backtrace support/detection
libexecinfo is used to provide backtrace() on *BSD. The API is
compatible with glibc's, so this is a "free" improvement.
To improve configure behaviour, the following configure options are
modified/introduced:
* --enable-gcc-rdynamic now defaults to "on" if the compiler is gcc.
(I sadly wasn't able to find any documentation on the availability of
this option for llvm, even though at least the version I have
installed does support it)
* --enable-backtrace has been added. This behaves as off/auto/on
switch, i.e. giving either {dis,en}able will result in the requested
behaviour (or an error if support wasn't found)
Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
3 files changed