[PATCH] Add DAP support for C++ exceptions

[Tom Tromey <tromey@adacore.com>]

This adds DAP support for the various C++ exception-catching
operations.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30682
---
 gdb/python/lib/gdb/dap/breakpoint.py    | 21 +++++++--
 gdb/testsuite/gdb.dap/cxx-exception.cc  | 44 +++++++++++++++++++
 gdb/testsuite/gdb.dap/cxx-exception.exp | 58 +++++++++++++++++++++++++
 3 files changed, 119 insertions(+), 4 deletions(-)
 create mode 100644 gdb/testsuite/gdb.dap/cxx-exception.cc
 create mode 100644 gdb/testsuite/gdb.dap/cxx-exception.exp

diff --git a/gdb/python/lib/gdb/dap/breakpoint.py b/gdb/python/lib/gdb/dap/breakpoint.py
index 27745ebfd2c..5f928f4c0ef 100644
--- a/gdb/python/lib/gdb/dap/breakpoint.py
+++ b/gdb/python/lib/gdb/dap/breakpoint.py
@@ -295,10 +295,8 @@ def set_insn_breakpoints(
 
 @in_gdb_thread
 def _catch_exception(filterId, **args):
-    if filterId == "assert":
-        cmd = "-catch-assert"
-    elif filterId == "exception":
-        cmd = "-catch-exception"
+    if filterId in ("assert", "exception", "throw", "rethrow", "catch"):
+        cmd = "-catch-" + filterId
     else:
         raise Exception(f"Invalid exception filterID: {filterId}")
     result = gdb.execute_mi(cmd)
@@ -346,6 +344,21 @@ def _rewrite_exception_breakpoint(
             "label": "Ada exceptions",
             "supportsCondition": True,
         },
+        {
+            "filter": "throw",
+            "label": "C++ exceptions, when thrown",
+            "supportsCondition": True,
+        },
+        {
+            "filter": "rethrow",
+            "label": "C++ exceptions, when re-thrown",
+            "supportsCondition": True,
+        },
+        {
+            "filter": "catch",
+            "label": "C++ exceptions, when caught",
+            "supportsCondition": True,
+        },
     ),
 )
 def set_exception_breakpoints(
diff --git a/gdb/testsuite/gdb.dap/cxx-exception.cc b/gdb/testsuite/gdb.dap/cxx-exception.cc
new file mode 100644
index 00000000000..b6afb90d289
--- /dev/null
+++ b/gdb/testsuite/gdb.dap/cxx-exception.cc
@@ -0,0 +1,44 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2023 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/>.  */
+
+int
+do_throw (int i)
+{
+  throw i;
+}
+
+int
+catcher (int x)
+{
+  return x;
+}
+
+int main()
+{
+  try {
+    try {
+      do_throw (20);
+    }
+    catch (int x) {
+      catcher (x);
+      throw;
+    }
+  }
+  catch (int y) {
+    catcher (y);
+  }
+}
diff --git a/gdb/testsuite/gdb.dap/cxx-exception.exp b/gdb/testsuite/gdb.dap/cxx-exception.exp
new file mode 100644
index 00000000000..46d4369a0f7
--- /dev/null
+++ b/gdb/testsuite/gdb.dap/cxx-exception.exp
@@ -0,0 +1,58 @@
+# Copyright 2023 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/>.
+
+load_lib ada.exp
+load_lib dap-support.exp
+
+require allow_cplus_tests allow_dap_tests
+
+standard_testfile .cc
+
+if {[build_executable ${testfile}.exp $testfile $srcfile {debug c++}] == -1} {
+    return
+}
+
+if {[dap_launch $testfile] == ""} {
+    return
+}
+
+set obj [dap_check_request_and_response "set exception catchpoints" \
+	     setExceptionBreakpoints \
+	     {o filters [a [s throw] [s rethrow] [s catch]]}]
+
+set bps [dict get [lindex $obj 0] body breakpoints]
+# We should get three responses, because we requested three
+# breakpoints.
+gdb_assert {[llength $bps] == 3} "three breakpoints"
+
+dap_check_request_and_response "start inferior" configurationDone
+
+dap_wait_for_event_and_check "stopped at throw" stopped \
+    "body reason" breakpoint \
+    "body hitBreakpointIds" 1
+
+dap_check_request_and_response "continue to catch" continue \
+    {o threadId [i 1]}
+dap_wait_for_event_and_check "stopped at catch" stopped \
+    "body reason" breakpoint \
+    "body hitBreakpointIds" 3
+
+dap_check_request_and_response "continue to rethrow" continue \
+    {o threadId [i 1]}
+dap_wait_for_event_and_check "stopped at rethrow" stopped \
+    "body reason" breakpoint \
+    "body hitBreakpointIds" 2
+
+dap_shutdown
-- 
2.40.1