Guile: temporary breakpoints

Adds API to the Guile bindings for creating temporary breakpoints and
querying whether an existing breakpoint object is temporary. This is
effectively a transliteration of the Python implementation.

It's worth noting that the added `is_temporary' flag is ignored in the
watchpoint registration path. This replicates the behaviour of the
Python implementation, but might be a bit surprising for users.

gdb/ChangeLog:

2021-06-09  George Barrett  <bob@bob131.so>

	* guile/scm-breakpoint.c (gdbscm_breakpoint_object::spec): Add
	is_temporary field.
	(temporary_keyword): Add keyword object for make-breakpoint
	argument parsing.
	(gdbscm_make_breakpoint): Accept #:temporary keyword argument
	and store the value in the allocated object's
	spec.is_temporary.
	(gdbscm_register_breakpoint_x): Pass the breakpoint's
	spec.is_temporary value to create_breakpoint.
	(gdbscm_breakpoint_temporary): Add breakpoint-temporary?
	procedure implementation.
	(breakpoint_functions::make-breakpoint): Update documentation
	string and fix a typo.
	(breakpoint_functions::breakpoint-temporary?): Add
	breakpoint-temporary? procedure.
	(gdbscm_initialize_breakpoints): Initialise temporary_keyword
	variable.
	NEWS (Guile API): Mention new temporary breakpoints API.

gdb/doc/ChangeLog:

2021-06-09  George Barrett  <bob@bob131.so>

	* guile.texi (Breakpoints In Guile): Update make-breakpoint
	documentation to reflect new #:temporary argument.
	Add documentation for new breakpoint-temporary? procedure.

gdb/testsuite/ChangeLog:

2021-06-09  George Barrett  <bob@bob131.so>

	* gdb.guile/scm-breakpoint.exp: Add additional tests for
	temporary breakpoints.

Change-Id: I2de332ee7c256f5591d7141ab3ad50d31b871d17

1 files changed, 15 insertions, 1 deletions

diff --git a/gdb/doc/guile.texi b/gdb/doc/guile.texi
index 36fc9a7..a2448dd 100644
--- a/gdb/doc/guile.texi
+++ b/gdb/doc/guile.texi
@@ -2965,7 +2965,7 @@ The following breakpoint-related procedures are provided by the
 @code{(gdb)} module:
 
 @c TODO: line length
-@deffn {Scheme Procedure} make-breakpoint location @r{[}#:type type@r{]} @r{[}#:wp-class wp-class@r{]} @r{[}#:internal internal@r{]}
+@deffn {Scheme Procedure} make-breakpoint location @r{[}#:type type@r{]} @r{[}#:wp-class wp-class@r{]} @r{[}#:internal internal@r{]} @r{[}#:temporary temporary@r{]}
 Create a new breakpoint at @var{location}, a string naming the
 location of the breakpoint, or an expression that defines a watchpoint.
 The contents can be any location recognized by the @code{break} command,
@@ -2991,6 +2991,11 @@ registered, nor will it be listed in the output from @code{info breakpoints}
 If an internal flag is not provided, the breakpoint is visible
 (non-internal).
 
+The optional @var{temporary} argument makes the breakpoint a temporary
+breakpoint.  Temporary breakpoints are deleted after they have been hit,
+after which the Guile breakpoint is no longer usable (although it may be
+re-registered with @code{register-breakpoint!}).
+
 When a watchpoint is created, @value{GDBN} will try to create a
 hardware assisted watchpoint.  If successful, the type of the watchpoint
 is changed from @code{BP_WATCHPOINT} to @code{BP_HARDWARE_WATCHPOINT}
@@ -3087,6 +3092,15 @@ Return the breakpoint's number --- the identifier used by
 the user to manipulate the breakpoint.
 @end deffn
 
+@deffn {Scheme Procedure} breakpoint-temporary? breakpoint
+Return @code{#t} if the breakpoint was created as a temporary
+breakpoint.  Temporary breakpoints are automatically deleted after
+they've been hit.  Calling this procedure, and all other procedures
+other than @code{breakpoint-valid?} and @code{register-breakpoint!},
+will result in an error after the breakpoint has been hit (since it has
+been automatically deleted).
+@end deffn
+
 @deffn {Scheme Procedure} breakpoint-type breakpoint
 Return the breakpoint's type --- the identifier used to
 determine the actual breakpoint type or use-case.