On Wed, 2014-04-09 at 19:03 -0700, Luca Clementi wrote: > On Wed, Apr 9, 2014 at 3:50 PM, Dima Kogan <[email protected]> wrote: > > > > Petr Machata <[email protected]> writes: > > > > > Dima Kogan <[email protected]> writes: > > > > > >> Currently it appears that all function prototypes are read from the > > >> .conf files. Can these be read in from the debug information instead? > > > > > > They sure can. > > > > > >> ltrace already uses libdw, so I'm assuming either this is not possible, > > >> or it's on somebody's short-term todo list. Any thoughts about it? > > > > > > It uses it optionally for unwinding, yes. It could use it optionally > > > for prototype retrieval as well. This idea has crossed my mind in the > > > past, and I wouldn't oppose patches that extend ltrace into accepting > > > debuginfo if available. > > > > OK, I'll take a look. By the way, what was the issue with libunwind? > > Isn't unwinding the whole point of that library? > > > > Few month ago Mark posted a patch to alternatively use elfutils to > unwind the stack (instead of libunwind). > They both do the same thing and share also a lot of code. > > https://www.mail-archive.com/[email protected]/msg00731.html
Yes, there is nothing wrong with libunwind, the elfutils libdw unwinder mostly is just an alternative right now. But since libdw does know more about DWARF it can also provide more functionality. The only added functionality over libunwind it currently provides is displaying source files and lines in the backtrace. I haven't really thought about any additional functionality that ltrace could use when using libdw. But one thing might be sharing the function symbol names since libdw can extract them from either the main ELF .dynsym table, the possibly separate .debug full .symtab table or the new .gnu_debugdata section if available. Another might indeed be extracting and using more of the DWARF data. I am happy to help review any suggested patches. Cheers, Mark _______________________________________________ Ltrace-devel mailing list [email protected] http://lists.alioth.debian.org/cgi-bin/mailman/listinfo/ltrace-devel
