Implement DAP breakpointLocations request

This implements the DAP breakpointLocations request.

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

@@ -25,6 +25,7 @@ from . import bt
 from . import disassemble
 from . import evaluate
 from . import launch
+from . import locations
 from . import memory
 from . import next
 from . import pause

gdb/python/lib/gdb/dap/locations.py

@@ -0,0 +1,45 @@
+# 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
+
+# This is deprecated in 3.9, but required in older versions.
+from typing import Optional
+
+from .server import request
+from .startup import in_gdb_thread, send_gdb_with_response
+
+
+@in_gdb_thread
+def _find_lines(filename, start_line, end_line):
+    lines = set()
+    for entry in gdb.execute_mi("-symbol-list-lines", filename)["lines"]:
+        line = entry["line"]
+        if line >= start_line and line <= end_line:
+            lines.add(line)
+    return {"breakpoints": [{"line": x} for x in sorted(lines)]}
+
+
+@request("breakpointLocations")
+def breakpoint_locations(*, source, line: int, endLine: Optional[int] = None, **extra):
+    if endLine is None:
+        endLine = line
+    if "path" in source:
+        filename = source["path"]
+    elif "name" in source:
+        filename = source["name"]
+    else:
+        raise Exception("")
+    return send_gdb_with_response(lambda: _find_lines(filename, line, endLine))