Pedro Alves
cb1e4e32c2
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"'.
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