Implement DAP modules request

This implements the DAP "modules" request, and also arranges to add
the module ID to stack frames.

gdb/python/lib/gdb/dap/__init__.py

@@ -27,6 +27,7 @@ from . import evaluate
 from . import launch
 from . import locations
 from . import memory
+from . import modules
 from . import next
 from . import pause
 from . import scopes

gdb/python/lib/gdb/dap/bt.py

@@ -18,6 +18,7 @@ import os
 
 from gdb.frames import frame_iterator
 from .frames import frame_id
+from .modules import module_id
 from .server import request, capability
 from .startup import send_gdb_with_response, in_gdb_thread
 from .state import set_thread
@@ -39,6 +40,7 @@ def _backtrace(thread_id, levels, startFrame):
     except gdb.error:
         frame_iter = ()
     for current_frame in frame_iter:
+        pc = current_frame.address()
         newframe = {
             "id": frame_id(current_frame),
             "name": current_frame.function(),
@@ -47,8 +49,11 @@ def _backtrace(thread_id, levels, startFrame):
             "line": 0,
             # GDB doesn't support columns.
             "column": 0,
-            "instructionPointerReference": hex(current_frame.address()),
+            "instructionPointerReference": hex(pc),
         }
+        objfile = gdb.current_progspace().objfile_for_address(pc)
+        if objfile is not None:
+            newframe["moduleId"] = module_id(objfile)
         line = current_frame.line()
         if line is not None:
             newframe["line"] = line

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

@@ -19,6 +19,7 @@ import gdb
 from .server import send_event
 from .startup import in_gdb_thread, Invoker, log
 from .breakpoint import breakpoint_descriptor
+from .modules import is_module, make_module
 
 
 @in_gdb_thread
@@ -78,6 +79,18 @@ def _new_thread(event):
     )
 
 
+@in_gdb_thread
+def _new_objfile(event):
+    if is_module(event.new_objfile):
+        send_event(
+            "module",
+            {
+                "reason": "new",
+                "module": make_module(event.new_objfile),
+            },
+        )
+
+
 _suppress_cont = False
 
 
@@ -161,3 +174,4 @@ gdb.events.breakpoint_modified.connect(_bp_modified)
 gdb.events.breakpoint_deleted.connect(_bp_deleted)
 gdb.events.new_thread.connect(_new_thread)
 gdb.events.cont.connect(_cont)
+gdb.events.new_objfile.connect(_new_objfile)

gdb/python/lib/gdb/dap/modules.py

@@ -0,0 +1,64 @@
+# 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/>.
+
+import gdb
+
+from .server import capability, request
+from .startup import in_gdb_thread, send_gdb_with_response
+
+
+@in_gdb_thread
+def module_id(objfile):
+    """Return the module ID for the objfile."""
+    return objfile.username
+
+
+@in_gdb_thread
+def is_module(objfile):
+    """Return True if OBJFILE represents a valid Module."""
+    return objfile.is_valid() and objfile.owner is None
+
+
+@in_gdb_thread
+def make_module(objf):
+    """Return a Module representing the objfile OBJF.
+
+    The objfile must pass the 'is_module' test."""
+    return {
+        "id": module_id(objf),
+        "name": objf.username,
+        "path": objf.filename,
+    }
+
+
+@in_gdb_thread
+def _modules(start, count):
+    # Don't count invalid objfiles or separate debug objfiles.
+    objfiles = [x for x in gdb.objfiles() if is_module(x)]
+    if count == 0:
+        # Use all items.
+        last = len(objfiles)
+    else:
+        last = start + count
+    return {
+        "modules": [make_module(x) for x in objfiles[start:last]],
+        "totalModules": len(objfiles),
+    }
+
+
+@capability("supportsModulesRequest")
+@request("modules")
+def modules(*, startModule: int = 0, moduleCount: int = 0, **args):
+    return send_gdb_with_response(lambda: _modules(startModule, moduleCount))