binutils-gdb/gdb/testsuite/gdb.cp/except-multi-location.exp
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

88 lines
3.0 KiB
Plaintext

# Copyright 2019 Free Software Foundation, Inc.
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
# Regression test for a GDB internal error that would trigger if a
# "catch catch" catchpoint ended up with multiple locations. This
# testcase exercises that scenario by building the binary with
# -static-libgcc/-static-libstdc++ and a shared library that depends
# on the libstc++.so DSO (which is how GDB was built and revealed the
# bug), and vice versa.
if {[skip_shlib_tests]} {
return 0
}
# STATIC_BIN indicates whether to build the main binary with
# -static-libgcc/-static-libstdc++. STATIC_LIB is the same, but for
# the shared library.
proc test_multi_libstdcpp {static_bin static_lib} {
global srcdir subdir
global decimal hex
# Library file.
set libname "except-multi-location-lib"
set srcfile_lib ${srcdir}/${subdir}/${libname}.cc
set binfile_lib [standard_output_file ${libname}-$static_bin-$static_lib.so]
set lib_flags {debug c++}
if {$static_lib} {
lappend lib_flags additional_flags=-static-libgcc additional_flags=-static-libstdc++
}
# Binary file.
set testfile "except-multi-location-main"
set srcfile ${srcdir}/${subdir}/${testfile}.cc
set binfile [standard_output_file ${testfile}-$static_bin-$static_lib]
set bin_flags [list debug c++ shlib=${binfile_lib}]
if {$static_bin} {
lappend bin_flags additional_flags=-static-libgcc additional_flags=-static-libstdc++
}
if { [gdb_compile_shlib ${srcfile_lib} ${binfile_lib} $lib_flags] != ""
|| [gdb_compile ${srcfile} ${binfile} executable $bin_flags] != "" } {
untested "failed to compile"
return -1
}
clean_restart
gdb_load ${binfile}
gdb_load_shlib $binfile_lib
if ![runto_main] {
fail "can't run to main"
return 0
}
gdb_test "catch catch" "Catchpoint \[0-9\]+ \\(catch\\)" \
"catch catch"
gdb_test "catch throw" "Catchpoint \[0-9\]+ \\(throw\\)" \
"catch throw"
gdb_test "catch rethrow" "Catchpoint \[0-9\]+ \\(rethrow\\)" \
"catch rethrow"
set ws "\[ \t\]*"
gdb_test "info breakpoints" \
[multi_line \
"${decimal}${ws}catchpoint${ws}keep${ws}y${ws}exception catch" \
"${decimal}${ws}catchpoint${ws}keep${ws}y${ws}exception throw" \
"${decimal}${ws}catchpoint${ws}keep${ws}y${ws}exception rethrow"]
}
# Try different static/not-static combinations.
foreach_with_prefix static_lib {"0" "1"} {
foreach_with_prefix static_bin {"0" "1"} {
test_multi_libstdcpp $static_lib $static_bin
}
}