Implement DAP module-removed event

DAP specifies an event that should be sent when a module is removed.
This patch implements this.

Tested-By: Alexandra Petlanova Hajkova <ahajkova@redhat.com>

gdb/python/lib/gdb/dap/events.py

@@ -68,6 +68,18 @@ def _new_objfile(event):
         )
 
 
+@in_gdb_thread
+def _objfile_removed(event):
+    if is_module(event.objfile):
+        send_event(
+            "module",
+            {
+                "reason": "removed",
+                "module": make_module(event.objfile),
+            },
+        )
+
+
 _suppress_cont = False
 
 
@@ -150,3 +162,4 @@ gdb.events.new_thread.connect(_new_thread)
 gdb.events.thread_exited.connect(_thread_exited)
 gdb.events.cont.connect(_cont)
 gdb.events.new_objfile.connect(_new_objfile)
+gdb.events.free_objfile.connect(_objfile_removed)

gdb/testsuite/gdb.dap/modules.c

@@ -36,5 +36,8 @@ main (void)
   func = (int (*)(void (*) (void))) dlsym (handle, "call_me");
   func (stop);
 
+  dlclose (handle);
+  stop ();
+
   return 0;
 }

gdb/testsuite/gdb.dap/modules.exp

@@ -42,7 +42,7 @@ if {[dap_launch $testfile] == ""} {
     return
 }
 
-set obj [dap_check_request_and_response "set breakpoint on two functions" \
+set obj [dap_check_request_and_response "set breakpoint on stop function" \
 	     setFunctionBreakpoints \
 	     {o breakpoints [a [o name [s stop]]]}]
 set fn_bpno [dap_get_breakpoint_number $obj]
@@ -53,7 +53,7 @@ dap_wait_for_event_and_check "stopped at function breakpoint" stopped \
     "body reason" breakpoint \
     "body hitBreakpointIds" $fn_bpno
 
-dap_check_request_and_response "continue to next stop" continue \
+dap_check_request_and_response "continue to second stop" continue \
     {o threadId [i 1]}
 
 
@@ -78,4 +78,15 @@ set frame_id [dict get [lindex [dict get $bt body stackFrames] 1] moduleId]
 
 gdb_assert {[string match *$libname* $frame_id]} "module.id in stack trace"
 
+
+dap_check_request_and_response "continue to third stop" continue \
+    {o threadId [i 1]}
+
+dap_wait_for_event_and_check "module removed event" module \
+    "body reason" removed
+
+dap_wait_for_event_and_check "third stop at function breakpoint" stopped \
+    "body reason" breakpoint \
+    "body hitBreakpointIds" $fn_bpno
+
 dap_shutdown