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Andrew Burgess 31fa6221bf gdb/readline: don't get stuck thinking an EOF arrived
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>
2024-11-12 14:07:35 +00:00
bfd Remove redundant section merge hash table field 2024-11-12 17:06:35 +10:30
binutils RISC-V: Dump instruction without checking architecture support as usual. 2024-10-31 11:28:45 +08:00
config Revert "Remove LIBINTL_DEP" 2024-06-20 21:15:27 +09:30
contrib Revert "contrib: Add autoregen.py" 2024-09-04 13:38:57 +00:00
cpu Add markers for 2.43 branch/release 2024-07-20 12:43:19 +01:00
elfcpp Add markers for 2.43 branch/release 2024-07-20 12:43:19 +01:00
etc Update year range in copyright notice of binutils files 2024-01-04 22:58:12 +10:30
gas aarch64: testsuite: remove hard-coded instruction addresses 2024-11-08 11:35:46 +00:00
gdb gdb/readline: don't get stuck thinking an EOF arrived 2024-11-12 14:07:35 +00:00
gdbserver gdbserver: pass osabi to GDB in more target descriptions 2024-11-12 12:51:36 +00:00
gdbsupport [gdb/tdep] Use raw_supply_part_zeroed for AArch64 2024-11-12 11:37:50 +01:00
gnulib autoupdate: replace obsolete macros AC_CONFIG_HEADER 2024-06-10 08:25:55 +09:30
gold gold: Always resolve non-default weak undefined to 0 2024-08-31 04:28:43 -07:00
gprof Updated Brazilian Portuguese translation for the gprof directory. 2024-09-26 16:11:59 +01:00
gprofng gprofng: use gprofng- prefix for gprofng binaries 2024-11-01 16:46:21 -07:00
include aarch64: improve debuggability on array of enum 2024-11-08 11:35:46 +00:00
ld Re: ld: Move note sections after .rodata section 2024-11-12 17:06:35 +10:30
libbacktrace autoupdate: regen after replacing obsolete macros 2024-06-10 08:25:56 +09:30
libctf binutils testsuite: canonicalize subtest names in libctf 2024-09-24 21:50:41 -04:00
libdecnumber regen config 2023-08-12 10:27:57 +09:30
libiberty libiberty: sync with gcc 2024-09-04 15:35:42 +01:00
libsframe libsframe: remove runstatedir in Makefile.in 2024-07-10 10:24:45 +02:00
opcodes aarch64: add flag OPD_F_UNSIGNED to distinguish signedness of immediate operands 2024-11-08 11:35:46 +00:00
readline autoupdate: add square brackets around arguments of AC_INIT 2024-06-10 08:25:56 +09:30
sim sim: pru: Fix test case assembly with latest GAS 2024-08-12 23:33:59 +03:00
texinfo
zlib autoupdate: regen after replacing obsolete macros 2024-06-10 08:25:56 +09:30
.cvsignore
.editorconfig
.gitattributes binutils-gdb/git: highlight whitespace errors in source files 2022-07-25 14:35:41 +01:00
.gitignore .gitignore: ignore .vscode 2024-05-30 12:09:35 +01:00
.pre-commit-config.yaml pre-commit: autoupdate 2024-08-12 13:07:59 -04:00
ar-lib
ChangeLog Add markers for 2.43 branch/release 2024-07-20 12:43:19 +01:00
compile
config-ml.in MSP430: Add -fno-exceptions multilib 2023-08-12 10:24:26 +09:30
config.guess Synchronize config.[sub|guess] with the latest versions from the config project. 2024-07-15 10:22:54 +01:00
config.rpath
config.sub Synchronize config.[sub|guess] with the latest versions from the config project. 2024-07-15 10:22:54 +01:00
configure Deprecate the ARM simulator. 2024-11-07 14:53:26 +00:00
configure.ac Deprecate the ARM simulator. 2024-11-07 14:53:26 +00:00
COPYING
COPYING3
COPYING3.LIB
COPYING.LIB
COPYING.LIBGLOSS
COPYING.NEWLIB
depcomp
djunpack.bat
install-sh
libtool.m4 FDPIC: Handle arm*-*-uclinuxfdpiceabi in configure scripts 2023-08-12 10:25:06 +09:30
lt~obsolete.m4
ltgcc.m4
ltmain.sh ltmain.sh: allow more flags at link-time 2024-09-25 19:06:10 +01:00
ltoptions.m4
ltsugar.m4
ltversion.m4
MAINTAINERS Fix compiling bfd/vms-lib.c for a 32-bit host. 2024-03-18 10:26:16 +00:00
Makefile.def Revert "Pass GUILE down to subdirectories" 2024-03-22 11:07:28 -06:00
Makefile.in Revert "Pass GUILE down to subdirectories" 2024-03-22 11:07:28 -06:00
Makefile.tpl Revert "Pass GUILE down to subdirectories" 2024-03-22 11:07:28 -06:00
makefile.vms
missing
mkdep
mkinstalldirs
move-if-change
multilib.am
README
README-maintainer-mode Note that at least dejagnu version 1.5.3 is required in order to be ale to run the testsuites. 2022-10-04 10:54:19 +01:00
SECURITY.txt Add a SECURITY.txt file describing the GNU Binutils' project's stance on security related bugs. 2023-04-20 16:52:11 +01:00
setup.com
src-release.sh Add a target to src-release.sh to crate a binutils release without Gold 2024-10-29 11:50:04 +00:00
symlink-tree
test-driver
ylwrap

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