Under gdb-mi can I attach a command to a breakpoint?

Question

I use gdb-mi in order to have access to gdb-many-windows functionality.

I would like to access gdb's ability to attach a list of commands to execute once a breakpoint gets hit. Documentation suggests that the gdb/mi protocol supports this via the -break-commands verb. That said, there is a cryptic suggestion of a rough edge earlier in that same documentation.

So am I just out of luck or is there some magic emacs or gud incantation that will grant me access to -break-commands functionality?

Answer 1

Given the "rough edge" I referenced in my original question I decided to investigate prompt handling in gud.el. Based on nothing more than a hunch I tried changing the two lines (~783 in function gud-gdb) from:

  (setq comint-prompt-regexp "^(.*gdb[+]?) *")
  (setq paragraph-start comint-prompt-regexp)

to

  (setq comint-prompt-regexp "^>|((.*gdb[+]?) *)")
  (setq paragraph-start "^(.*gdb[+]?) *")

This has the effect of preserving paragraph separation according to the original regex prompt pattern while allowing stripping of the single leading '>' prompt that gdb uses when collecting a commands list.

Amazingly it seems to work! Though info br shows breakpoint associated commands lists the gdb-many-windows Breakpoints window gives no indication of their existence. But that is a small nit. For now I am happy.

Answer 2

I also like to use commands attached to a breakpoint. If I enter the gdb command: comm 3, it starts collecting the commands for the breakpoint, but when I enter end it does not recognize the command list has been completed and continues to prompt for more commands. However, if I enter the full gdb command name, commands 3, then it does recognize that end command and the command attachments work.