binutils-gdb/gdb/doc
Pedro Alves cb1e4e32c2 "catch catch/throw/rethrow", breakpoint -> catchpoint
Currently, with:

 (gdb) catch catch
 Catchpoint 1 (catch)
 (gdb) catch throw
 Catchpoint 2 (throw)
 (gdb) catch rethrow
 Catchpoint 3 (rethrow)

You get:

(gdb) info breakpoints
 Num     Type           Disp Enb Address            What
 1       breakpoint     keep y   0x0000000000b122af exception catch
 2       breakpoint     keep y   0x0000000000b1288d exception throw
 3       breakpoint     keep y   0x0000000000b12931 exception rethrow

I think it doesn't make much sense usability-wise, to show a
catchpoint as a breakpoint.  The fact that GDB sets a breakpoint at
some magic address in the C++ run time is an implementation detail,
IMO.  And as seen in the previous patch, such a catchpoint can end up
with more than one location/address even, so showing a single address
isn't entirely accurate.

This commit hides the addresses from view, and makes GDB show
"catchpoint" for type as well:

  (gdb) info breakpoints
  Num     Type           Disp Enb Address            What
  1       catchpoint     keep y                      exception catch
  2       catchpoint     keep y                      exception throw
  3       catchpoint     keep y                      exception rethrow

This comment in the code seems telling:

  /* We need to reset 'type' in order for code in breakpoint.c to do
     the right thing.  */
  cp->type = bp_breakpoint;

It kind of suggests that the reason catchpoints end up shown as
breakpoints was that it was easier to implement them that way, rather
than a desired property.

This commit fixes things up to make it possible to have bp_catch
breakpoints have software/hardware breakpoint locations, thus
eliminating the need for that hack:

 - redo breakpoint_address_is_meaningful in terms of the location's
   type rather than breakpoint type.
 - teach bpstat_what about stepping over the catchpoint locations.
 - install a allocate_location method for "catch catch/throw/rethrow",
   one that forces the location type.

Note that this also reverts the gdb hunk from:

  commit 2a8be20359
  Commit:     Tom Tromey <tom@tromey.com>
  CommitDate: Sat Oct 6 22:17:45 2018 -0600

      Fix Python gdb.Breakpoint.location crash

because now "catch throw" catchpoints hit the

   if (obj->bp->type != bp_breakpoint)
     Py_RETURN_NONE;

check above, and, adjusts the testcase to no longer expect to see the
catchpoint in the gdb.breakpoints() list.

(Note: might make sense to do the same to Ada exception catchpoints.)

gdb/ChangeLog:
2019-07-09  Pedro Alves  <palves@redhat.com>

	* break-catch-throw.c (print_one_exception_catchpoint): Skip the
	"addr" field.
	(allocate_location_exception_catchpoint): New.
	(handle_gnu_v3_exceptions): Don't reset 'type' to bp_breakpoint.
	(initialize_throw_catchpoint_ops): Install
	allocate_location_exception_catchpoint as allocate_location
	method.
	* breakpoint.c (bpstat_what) <bp_catch>: Set action to
	BPSTAT_WHAT_SINGLE if not stopping and the location's type is not
	bp_loc_other.
	(breakpoint_address_is_meaningful): Delete.
	(bl_address_is_meaningful): New.
	(breakpoint_locations_match): Adjust comment.
	(bp_location_from_bp_type): New, factored out of...
	(bp_location::bp_location(breakpoint *)): ... this.
	(bp_location::bp_location(breakpoint *, bp_loc_type)): New,
	factored out of...
	(bp_location::bp_location(breakpoint *)): ... this.  Reimplement.
	(bp_loc_is_permanent): Use bl_address_is_meaningful instead of
	breakpoint_address_is_meaningful.
	(bp_locations_compare): Adjust comment.
	(update_global_location_list): Use bl_address_is_meaningful
	instead of breakpoint_address_is_meaningful.
	* breakpoint.h (bp_location::bp_location(breakpoint *)): New
	explicit.
	(bp_location::bp_location(breakpoint *, bp_loc_type)): Declare.
	* python/py-breakpoint.c (bppy_get_location): No longer check
	whether location is null.

gdb/doc/ChangeLog:
2019-07-09  Pedro Alves  <palves@redhat.com>

	* gdb.texinfo (C++ Exception GDB/MI Catchpoint Commands): Adjust
	examples to show type=catchpoint instead of type=breakpoint and an
	address.

gdb/testsuite/ChangeLog:
2019-07-09  Pedro Alves  <palves@redhat.com>

	* gdb.cp/catch-multi-stdlib.exp: Adjust expected "info
	breakpoints" output.
	* gdb.cp/exception.exp: Adjust expected "info breakpoints" output.
	* gdb.python/py-breakpoint.exp: No longer expect that "catch
	throw" creates breakpoint.
	* gdb.mi/mi-catch-cpp-exceptions.exp (setup_catchpoint): Expect
	'type="catchpoint"'.
2019-07-09 19:34:18 +01:00
..
.gitignore Update and add .gitignore's 2016-09-21 13:12:21 -04:00
a4rc.sed
agentexpr.texi Update copyright year range in all GDB files. 2019-01-01 10:01:51 +04:00
all-cfg.texi Update copyright year range in all GDB files. 2019-01-01 10:01:51 +04:00
annotate.texinfo Add thread-exit annotation. 2019-06-06 11:35:15 -06:00
ChangeLog "catch catch/throw/rethrow", breakpoint -> catchpoint 2019-07-09 19:34:18 +01:00
doxy-index.in Update copyright year range in all GDB files. 2019-01-01 10:01:51 +04:00
Doxyfile-base.in Update copyright year range in all GDB files. 2019-01-01 10:01:51 +04:00
Doxyfile-gdb-api.in Update copyright year range in all GDB files. 2019-01-01 10:01:51 +04:00
Doxyfile-gdb-xref.in Update copyright year range in all GDB files. 2019-01-01 10:01:51 +04:00
Doxyfile-gdbserver.in Update copyright year range in all GDB files. 2019-01-01 10:01:51 +04:00
fdl.texi
filter-for-doxygen
filter-params.pl
gdb.texinfo "catch catch/throw/rethrow", breakpoint -> catchpoint 2019-07-09 19:34:18 +01:00
gpl.texi
guile.texi gdb: Introduce 'print max-depth' feature 2019-04-29 22:01:09 +01:00
lpsrc.sed
Makefile.in Make "all" depend on "info" 2019-04-07 17:01:18 -06:00
psrc.sed
python.texi Add an objfile getter to gdb.Type 2019-06-04 09:46:06 -06:00
refcard.tex Update copyright year range in gdb.texinfo and refcard.tex 2019-02-23 16:19:57 +04:00
stabs.texinfo Update copyright year range in all GDB files. 2019-01-01 10:01:51 +04:00
stack_frame.eps
stack_frame.pdf From Jeremy Bennett <jeremy.bennett@embecosm.com>: 2009-03-21 10:24:35 +00:00
stack_frame.png
stack_frame.svg
stack_frame.txt