Andrew Burgess
661d98a333
This commit adds a new extension_language_ops hook which allows an extension to handle the case where GDB can't find a separate debug information file for a particular objfile. This commit doesn't actually implement the hook for any of GDB's extension languages, the next commit will do that. This commit just adds support for the hook to extension-priv.h and extension.[ch], and then reworks symfile-debug.c to call the hook. Right now the hook will always return its default value, which means GDB should do nothing different. As such, there should be no user visible changes after this commit. I'll give a brief description of what the hook does here so that we can understand the changes in symfile-debug.c. The next commit adds a Python implementation for this new hook, and gives a fuller description of the new functionality. Currently, when looking for separate debug information GDB tries three things, in this order: 1. Use the build-id to find the required debug information, 2. Check for .gnu_debuglink section and use that to look up the required debug information, 3. Check with debuginfod to see if it can supply the required information. The new extension_language_ops::handle_missing_debuginfo hook is called if all three steps fail to find any debug information. The hook has three possible return values: a. Nothing, no debug information is found, GDB continues without the debug information for this objfile. This matches the current behaviour of GDB, and is the default if nothing is implementing this new hook, b. Install debug information into a location that step #1 or #2 above would normally check, and then request that GDB repeats steps #1 and #2 in the hope that GDB will now find the debug information. If the debug information is still not found then GDB carries on without the debug information. If the debug information is found the GDB loads it and carries on, c. Return a filename for a file containing the required debug information. GDB loads the contents of this file and carries on. The changes in this commit mostly involve placing the core of objfile::find_and_add_separate_symbol_file into a loop which allows for steps #1 and #2 to be repeated. We take care to ensure that debuginfod is only queried once, the first time through. The assumption is that no extension is going to be able to control the replies from debuginfod, so there's no point making a second request -- and as these requests go over the network, they could potentially be slow. The warnings that find_and_add_separate_symbol_file collects are displayed only once assuming that no debug information is found. If debug information is found, even after the extension has operated, then the warnings are not shown; remember, these are warnings from GDB about failure to find any suitable debug information, so it makes sense to hide these if debug information is found. Approved-By: Tom Tromey <tom@tromey.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.