From: Tom Tromey <tromey@adacore.com>
To: gdb-patches@sourceware.org
Cc: Tom Tromey <tromey@adacore.com>
Subject: [PATCH] Add DAP scope cache
Date: Mon, 2 Oct 2023 12:36:15 -0600 [thread overview]
Message-ID: <20231002183615.161787-1-tromey@adacore.com> (raw)
Andry Ogorodnik, a co-worker, noticed that multiple "scopes" requests
with the same frame would yield different variableReference values in
the response.
This patch adds a regression test for this, and adds a scope cache in
scopes.py, ensuring that multiple identical requests will get the same
response.
---
gdb/python/lib/gdb/dap/scopes.py | 38 ++++++++++++++++++++++++--------
gdb/testsuite/gdb.dap/scopes.exp | 7 ++++++
2 files changed, 36 insertions(+), 9 deletions(-)
diff --git a/gdb/python/lib/gdb/dap/scopes.py b/gdb/python/lib/gdb/dap/scopes.py
index 4874d001216..5dde060f44f 100644
--- a/gdb/python/lib/gdb/dap/scopes.py
+++ b/gdb/python/lib/gdb/dap/scopes.py
@@ -21,6 +21,21 @@ from .server import request
from .varref import BaseReference
+# Map DAP frame IDs to scopes. This ensures that scopes are re-used.
+frame_to_scope = {}
+
+
+# When the inferior is re-started, we erase all scope references. See
+# the section "Lifetime of Objects References" in the spec.
+@in_gdb_thread
+def clear_scopes(event):
+ global frame_to_scope
+ frame_to_scope = {}
+
+
+gdb.events.cont.connect(clear_scopes)
+
+
class _ScopeReference(BaseReference):
def __init__(self, name, hint, frame, var_list):
super().__init__(name)
@@ -83,15 +98,20 @@ class _RegisterReference(_ScopeReference):
# Helper function to create a DAP scopes for a given frame ID.
@in_gdb_thread
def _get_scope(id):
- frame = frame_for_id(id)
- scopes = []
- args = frame.frame_args()
- if args:
- scopes.append(_ScopeReference("Arguments", "arguments", frame, args))
- locs = frame.frame_locals()
- if locs:
- scopes.append(_ScopeReference("Locals", "locals", frame, locs))
- scopes.append(_RegisterReference("Registers", frame))
+ global frame_to_scope
+ if id in frame_to_scope:
+ scopes = frame_to_scope[id]
+ else:
+ frame = frame_for_id(id)
+ scopes = []
+ args = frame.frame_args()
+ if args:
+ scopes.append(_ScopeReference("Arguments", "arguments", frame, args))
+ locs = frame.frame_locals()
+ if locs:
+ scopes.append(_ScopeReference("Locals", "locals", frame, locs))
+ scopes.append(_RegisterReference("Registers", frame))
+ frame_to_scope[id] = scopes
return [x.to_object() for x in scopes]
diff --git a/gdb/testsuite/gdb.dap/scopes.exp b/gdb/testsuite/gdb.dap/scopes.exp
index 6937badcca0..003557cf323 100644
--- a/gdb/testsuite/gdb.dap/scopes.exp
+++ b/gdb/testsuite/gdb.dap/scopes.exp
@@ -52,6 +52,13 @@ set scopes [dap_check_request_and_response "get scopes" scopes \
[format {o frameId [i %d]} $frame_id]]
set scopes [dict get [lindex $scopes 0] body scopes]
+# Request the scopes twice, and verify that the results are identical.
+# GDB previously had a bug where it would return new scopes each time.
+set scopes2 [dap_check_request_and_response "get scopes again" scopes \
+ [format {o frameId [i %d]} $frame_id]]
+set scopes2 [dict get [lindex $scopes2 0] body scopes]
+gdb_assert {$scopes2 == $scopes} "identical scopes requests yield same body"
+
gdb_assert {[llength $scopes] == 2} "two scopes"
lassign $scopes scope reg_scope
--
2.40.1
next reply other threads:[~2023-10-02 18:36 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-02 18:36 Tom Tromey [this message]
2023-10-03 12:16 ` Alexandra Petlanova Hajkova
2023-10-16 14:41 ` Tom Tromey
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