Andrew Burgess
4b2f71e6c6
This commit replaces the architecture_changed observer with a new_architecture observer. Currently the only user of the architecture_changed observer is the Python code, which uses this observer to register the Python unwinder with the architecture. The problem is that the architecture_changed observer is triggered from inferior::set_arch(), which only sees the inferior-wide gdbarch value. For targets that use thread-specific architectures, these never trigger the architecture_changed observer, and so never have the Python unwinder registered with them. When it comes to unwinding GDB makes use of the frame's gdbarch, which is based on the thread's regcache gdbarch, which is set in get_thread_regcache to the value returned from target_thread_architecture, which is not always the inferiors gdbarch value, it might be a thread-specific gdbarch which has not passed through inferior::set_arch(). The new_architecture observer will be triggered from gdbarch_find_by_info, whenever a new gdbarch is created and initialised. As GDB caches and reuses gdbarch values, we should expect to see each new architecture trigger the new_architecture observer just once. After this commit, targets that make use of thread-specific architectures should be able to make use of Python unwinders. As I don't have access to a machine that makes use of thread-specific architectures right now, I asked Luis to confirm that an AArch64 target that uses SVE/SME can't use the Python unwinders in threads that are using a thread-specific architectures, and he confirmed that this is indeed the case, see this discussion: https://inbox.sourceware.org/gdb/87wmvsat8i.fsf@redhat.com Tested-By: Lancelot Six <lancelot.six@amd.com> Tested-By: Luis Machado <luis.machado@arm.com> Reviewed-By: Luis Machado <luis.machado@arm.com> Approved-By: Simon Marchi <simon.marchi@efficios.com>
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.