The GUD interaction buffer uses a variant of Shell mode, so the Emacs commands of Shell mode are available (see Shell Mode). All the usual commands for your debugger are available, and you can use the Shell mode history commands to repeat them. If you wish, you can control your debugger process entirely through this buffer.
GUD mode also provides commands for setting and clearing
breakpoints, for selecting stack frames, and for stepping through the
program. These commands are available both in the GUD buffer and
globally, but with different key bindings. It also has its own tool
bar from which you can invoke the more common commands by clicking on
the appropriate icon. This is particularly useful for repetitive
gud-step, and allows you to
keep the GUD buffer hidden.
The breakpoint commands are normally used in source file buffers, because that is the easiest way to specify where to set or clear the breakpoint. Here's the global command to set a breakpoint:
Here are the other special commands provided by GUD. The keys starting with C-c are available only in the GUD interaction buffer. The key bindings that start with C-x C-a are available in the GUD interaction buffer and also in source files. Some of these commands are not available to all the supported debuggers.
gud-step). If the line contains a function call, execution stops after entering the called function.
gud-print). If Emacs does not print the exact expression that you want, mark it as a region first.
gud-remove). If you use this command in the GUD interaction buffer, it applies to the line where the program last stopped.
gud-tbreak). If you use this command in the GUD interaction buffer, it applies to the line where the program last stopped.
gud-up). This is equivalent to the GDB command ‘up’.
gud-down). This is equivalent to the GDB command ‘down’.
gud-until). The program will run until it hits a breakpoint, terminates, gets a signal that the debugger is checking for, or reaches the line on which the cursor currently sits.
If you are using GDB, these additional key bindings are available:
gud-jumptransfers the program's execution point to the current line. In other words, the next line that the program executes will be the one where you gave the command. If the new execution line is in a different function from the previously one, GDB prompts for confirmation since the results may be bizarre. See the GDB manual entry regarding
gud-gdb-complete-command). This key is available only in the GUD interaction buffer.
These commands interpret a numeric argument as a repeat count, when that makes sense.
Because <TAB> serves as a completion command, you can't use it to enter a tab as input to the program you are debugging with GDB. Instead, type C-q <TAB> to enter a tab.blog comments powered by Disqus