mirror of
https://github.com/espressif/binutils-gdb.git
synced 2025-12-19 01:19:41 +08:00
31fa6221bf
It was brought to my attention[1] that if a user makes use of Ctrl+d to quit from a secondary prompt (e.g. the prompt used to enter lines for the 'commands' command) then GDB will start displaying some unexpected blank lines. Here's an example: Reading symbols from /tmp/hello.x... (gdb) break main Breakpoint 1 at 0x401198: file hello.c, line 18. (gdb) commands Type commands for breakpoint(s) 1, one per line. End with a line saying just "end". >quit # <----------- Use Ctrl+d to quit here. (gdb) show architecture # <----------- This blank line is unexpected. The target architecture is set to "auto" (currently "i386:x86-64"). (gdb) I've marked up where I press 'Ctrl+d', and also the unexpected blank line. This issue will only happen if bracketed-paste-mode is in use. If this has been disabled (e.g. in ~/.inputrc) then this issue will not occur. The blank line is not just emitted for the 'show architecture' command. The blank line is actually caused by an extra '\n' character emitted by readline after it has gathered a complete line of input, and so will occur for any command. The problem is caused by readline getting "stuck" in a state where it thinks that an EOF has just been delivered. This state is set when the 'Ctrl+d' does deliver an EOF, but then this state is never fully reset. As a result, every time readline completes a line, it thinks that the line was completed due to an EOF and so adds an extra '\n' character. Obviously the real fix for this issue is to patch readline, and I do have a patch for that[2], however, version 8.2 of readline has been released, and contains this issue. As such, if GDB is linked against the system readline, and that system readline is 8.2, then we can expect to see this issue. There's a pretty simple, and cheap workaround that we can add to GDB that will mitigate this issue. I propose that we add this workaround to GDB. If/when the readline patch is accepted then I'll back-port this to our local readline copy, but retaining the workaround will be harmless, and will make GDB play nicer with system readline libraries (version 8.2). [1] https://inbox.sourceware.org/gdb-patches/34ef5438-8644-44cd-8537-5068e0e5e434@redhat.com [2] https://lists.gnu.org/archive/html/bug-readline/2024-10/msg00014.html Reviewed-By: Keith Seitz <keiths@redhat.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.