The <location-trap> class implements traps that are triggered
by evaluation of code at a specific source location. When compared
with source traps, they are easier to set, and do not become
irrelevant when the relevant code is reloaded; but unfortunately they
are a lot less efficient, as they require running some “are we in the
right place for a trap” code on every low level frame entry trap
call.
Class for traps triggered by evaluation of code at a specific source location.
A regular expression specifying the filenames that will match this trap. This option must be specified when creating a location trap.
The line number (0-based) of the source location at which the trap should be triggered. This option must be specified when creating a location trap.
The column number (0-based) of the source location at which the trap should be triggered. This option must be specified when creating a location trap.
Here is an example, which matches the (facti (- n 1) (* a n))
expression in ice-9/debugging/example-fns.scm:
(install-trap (make <location-trap>
#:file-regexp "example-fns.scm"
#:line 11
#:column 6
#:behaviour gds-debug-trap))