mirror of
https://github.com/darlinghq/darling-gdb.git
synced 2025-02-25 03:54:33 +00:00
3bd7e5b7ee
This patch is intended to make the interaction between the probes-based dynamic linker interface and the SystemTap SDT probe code on GDB more robust. It does that by wrapping the calls to the probe API with TRY...CATCH'es, so that any exception thrown will be caught and handled properly. The idea for this patch came from <https://bugzilla.redhat.com/show_bug.cgi?id=1196181>, which is a bug initially filed against Fedora GDB (but now under Fedora GLIBC). This bug happens on armhfp (although it could happen on other targets as well), and is triggered because GCC generates a strange argument for one of the probes used by GDB in the dynamic linker interface. As can be seen in the bug, this argument is "-4@.L1052". I don't want to discuss the reasons for this argument to be there (this discussion belongs to the bug, or to another thread), but GDB could definitely do a better error handling here. Currently, one sees the following message when there is an error in the probes-based dynamic linker interface: (gdb) run Starting program: /bin/inferior warning: Probes-based dynamic linker interface failed. Reverting to original interface. Cannot parse expression `.L976 4@r4'. (gdb) Which means that one needs to explicitly issue a "continue" command to make GDB continue running the inferior, even though this error is not fatal and GDB will fallback to the old interface automatically. This is where this patch helps: it makes GDB still print the necessary warnings or error messages, but it *also* does not stop the inferior unnecessarily. I have tested this patch on the systems where this error happens, but I could not come up with a way to create a testcase for it. Nevertheless, it should be straightforward to see that this patch does improve the current situation. gdb/ChangeLog: 2015-09-01 Sergio Durigan Junior <sergiodj@redhat.com> * solib-svr4.c (solib_event_probe_action): Call get_probe_argument_count using TRY...CATCH. (svr4_handle_solib_event): Likewise, for evaluate_probe_argument.
README for GNU development tools This directory contains various GNU compilers, assemblers, linkers, debuggers, etc., plus their support routines, definitions, and documentation. If you are receiving this as part of a GDB release, see the file gdb/README. If with a binutils release, see binutils/README; if with a libg++ release, see libg++/README, etc. That'll give you info about this package -- supported targets, how to use it, how to report bugs, etc. It is now possible to automatically configure and build a variety of tools with one command. To build all of the tools contained herein, run the ``configure'' script here, e.g.: ./configure make To install them (by default in /usr/local/bin, /usr/local/lib, etc), then do: make install (If the configure script can't determine your type of computer, give it the name as an argument, for instance ``./configure sun4''. You can use the script ``config.sub'' to test whether a name is recognized; if it is, config.sub translates it to a triplet specifying CPU, vendor, and OS.) If you have more than one compiler on your system, it is often best to explicitly set CC in the environment before running configure, and to also set CC when running make. For example (assuming sh/bash/ksh): CC=gcc ./configure make A similar example using csh: setenv CC gcc ./configure make Much of the code and documentation enclosed is copyright by the Free Software Foundation, Inc. See the file COPYING or COPYING.LIB in the various directories, for a description of the GNU General Public License terms under which you can copy the files. REPORTING BUGS: Again, see gdb/README, binutils/README, etc., for info on where and how to report problems.