* The 'set disassembler-options' command now supports specifying options
for the ARC target.
+* On GNU/Linux, by default GDB now starts programs associated with a
+ pseudo-terminal slave device created and managed by GDB, instead of
+ having the inferior use the same terminal as GDB directly. GDB
+ takes care of forwarding input and output to and from GDB's terminal
+ at appropriate times, so this is largely transparent.
+
+ In addition, by default, Ctrl-C no longer stops the program with
+ SIGINT. Instead you'll see for example:
+
+ Thread 1 "main" stopped.
+
+ With these changes it is now possible to interrupt programs that
+ block or ignore the SIGINT signal (with e.g., the sigprocmask
+ function), or use the sigwait function to wait for SIGINT signal.
+
+ You can use the "tty /dev/tty" command to restore the previous
+ behavior of spawning programs associated with the same terminal as
+ GDB.
+
* GDB now supports general memory tagging functionality if the underlying
architecture supports the proper primitives and hooks. Currently this is
enabled only for AArch64 MTE.
show debug event-loop
Control the display of debug output about GDB's event loop.
+set debug managed-tty
+show debug managed-tty
+ Control the display of debug output about GDB-managed terminals.
+
set print memory-tag-violations
show print memory-tag-violations
Control whether to display additional information about memory tag violations
@cindex redirection
@cindex i/o
@cindex terminal
-By default, the program you run under @value{GDBN} does input and output to
-the same terminal that @value{GDBN} uses. @value{GDBN} switches the terminal
-to its own terminal modes to interact with you, but it records the terminal
-modes your program was using and switches back to them when you continue
-running your program.
+By default, the program you run under @value{GDBN} does (or
+@value{GDBN} provides the illusion that it does) input and output to
+the same terminal that @value{GDBN} uses.
+
+Depending on the operating system and configuration, either:
+
+@itemize
+
+@item
+@value{GDBN} switches the terminal to its own terminal modes to
+interact with you, but it records the terminal modes your program was
+using and switches back to them when you continue running your
+program. This is the default on most systems.
+
+@item
+@value{GDBN} creates a pseudo-terminal, sets your program to use it
+for standard input and standard output, and forwards input and output
+to and from @value{GDBN}'s terminal at appropriate times. This is the
+default on GNU/Linux.
+
+@end itemize
@table @code
@kindex info terminal
default to do input and output on the terminal @file{/dev/ttyb} and have
that as their controlling terminal.
+On some operating systems, by default, @value{GDBN} creates a
+pseudo-terminal, and sets your program to use it for standard input
+and standard output. @value{GDBN} takes care of forwarding input and
+output to and from @value{GDBN}'s terminal at appropriate times, so
+this is largely transparent.
+
+On such systems, in some cases, like for example if you need to run
+your program and then detach it, and you want the program to remain
+associated with a terminal, you may prefer that @value{GDBN} starts
+your program using the same device for standard input and output as
+@value{GDBN} is using.
+
+Specifying the special @file{/dev/tty} file as input and output device
+is interpreted as a request for doing I/O to the same terminal that
+@value{GDBN} uses directly, skipping creation of an intermediary
+pseudo-terminal on systems where @value{GDBN} creates one by default.
+
+Note that on GNU/Linux at least, a consequence of using the same
+terminal as @value{GDBN} directly is that programs that block or
+ignore the @code{SIGINT} signal (with e.g., the @code{sigprocmask}
+function), or use the @code{sigwait} function to wait for
+@code{SIGINT} signals can not be interrupted by typing the interrupt
+character (often @kbd{Ctrl-c}).
+
An explicit redirection in @code{run} overrides the @code{tty} command's
effect on the input/output device, but not its effect on the controlling
terminal.
Show the current tty for the program being debugged.
@end table
+The management of @value{GDBN}-created terminals can be inspected
+using:
+
+@table @code
+@kindex set debug managed-tty
+@item set debug managed-tty @r{[}on|off@r{]}
+Set whether to print debug output about @value{GDBN}-managed
+terminals.
+
+@kindex show debug managed-tty
+@item show debug managed-tty
+Show whether the debug output about @value{GDBN}-managed terminals is
+printed.
+@end table
+
@node Attach
@section Debugging an Already-running Process
@kindex attach
@code{set confirm} command (@pxref{Messages/Warnings, ,Optional Warnings and
Messages}).
+On systems where @value{GDBN} creates a pseudo-terminal for spawned
+inferiors, detaching from a process that was started by @value{GDBN}
+(for example with the @code{run} command) results in the process
+losing its terminal right after detaching, because @value{GDBN}
+destroys the pseudo-terminal device pair. If you prefer, you can use
+the @code{tty} command command to instruct @value{GDBN} to start your
+program doing I/O to the same terminal that @value{GDBN} uses or to
+some other terminal. @xref{Input/Output, ,Your Program's Input and
+Output}.
+
@node Kill Process
@section Killing the Child Process
@menu
* Breakpoints:: Breakpoints, watchpoints, and catchpoints
* Continuing and Stepping:: Resuming execution
+* Interrupting:: Interrupting execution
* Skipping Over Functions and Files::
Skipping over functions and files
* Signals:: Signals
@end table
+@node Interrupting
+@section Interrupting
+
+You can stop the program while it is running in the foreground by
+pressing the interrupt character (often @kbd{Ctrl-c}). If the program
+is executing in the background (@pxref{Background Execution}), you can
+use the @code{interrupt} command (@pxref{interrupt}).
+
+Depending on operating system and configuration, this results in
+interrupting the program with either a @code{SIGINT} signal:
+
+@smallexample
+Program received signal SIGINT, Interrupt.
+@end smallexample
+
+@noindent
+or plainly suspending the program:
+
+@smallexample
+Program stopped.
+@end smallexample
+
+The terminal the program was started with affects whether you get the
+former or the latter. @xref{Input/Output, ,Your Program's Input and
+Output}.
+
+On systems where interrupting the program results in a plain
+suspension instead of the program receiving a @code{SIGINT} signal,
+you can still pass a @code{SIGINT} signal to the program after it
+stops, using either the @code{signal SIGINT} or @code{queue-signal
+SIGINT} commands. @xref{Signaling,,Giving your Program a Signal}.
+
+The remote target supports a number of options to configure how the
+remote program is interrupted. @xref{Remote Configuration}.
+
+@value{GDBN} on MS-Windows supports @kbd{C-@key{BREAK}} as an
+alternative interrupt key sequence. @xref{interrupt debuggee on
+MS-Windows}.
+
@node Skipping Over Functions and Files
@section Skipping Over Functions and Files
@cindex skipping over functions and files
@table @code
@kindex interrupt
+@anchor{interrupt}
@item interrupt
@itemx interrupt -a
@cindex Ctrl-BREAK, MS-Windows
@cindex interrupt debuggee on MS-Windows
+@anchor{interrupt debuggee on MS-Windows}
MS-Windows programs that call @code{SetConsoleMode} to switch off the
special meaning of the @samp{Ctrl-C} keystroke cannot be interrupted
by typing @kbd{C-c}. For this reason, @value{GDBN} on MS-Windows
projects / thirdparty / binutils-gdb.git / commitdiff
