From 30baee6865571bb0385dbc6ee7e06701e1253028 Mon Sep 17 00:00:00 2001 From: Tom Tromey Date: Tue, 1 Aug 2023 13:57:19 -0600 Subject: [PATCH] Use frame.name() in FrameDecorator A co-worker pointed out that gdb's DAP implementation might return an integer for the name of a stack frame, like: {"id": 1, "name": 93824992310799, ...} This can be seen currently in the logs of the bt-nodebug.exp test case. What is happening is that FrameDecorator falls back on returning the PC when the frame's function symbol cannot be found, relying on the gdb core to look up the minsym and print its name. This can actually yield the wrong answer sometimes, because it falls into the get_frame_pc / get_frame_address_in_block problem -- if the frame is at a call to a noreturn function, the PC in this case might appear to be in the next function in memory. For more on this, see: https://sourceware.org/bugzilla/show_bug.cgi?id=8416 and related bugs. However, there's a different approach we can take: the code here can simply use Frame.name. This handles the PC problem correctly, and gets us the information we need. --- gdb/python/lib/gdb/FrameDecorator.py | 15 ++++----------- gdb/testsuite/gdb.dap/bt-nodebug.exp | 9 ++++++++- 2 files changed, 12 insertions(+), 12 deletions(-) diff --git a/gdb/python/lib/gdb/FrameDecorator.py b/gdb/python/lib/gdb/FrameDecorator.py index aa9a2201bec..39ee2e2547c 100644 --- a/gdb/python/lib/gdb/FrameDecorator.py +++ b/gdb/python/lib/gdb/FrameDecorator.py @@ -75,17 +75,10 @@ class _FrameDecoratorBase(object): elif frame.type() == gdb.SIGTRAMP_FRAME: return "" - func = frame.function() - - # If we cannot determine the function name, return the - # address. If GDB detects an integer value from this function - # it will attempt to find the function name from minimal - # symbols via its own internal functions. - if func is None: - pc = frame.pc() - return pc - - return str(func) + func = frame.name() + if not isinstance(func, str): + func = "???" + return func def address(self): """Return the address of the frame's pc""" diff --git a/gdb/testsuite/gdb.dap/bt-nodebug.exp b/gdb/testsuite/gdb.dap/bt-nodebug.exp index e4dcef35a67..e9726d2e17d 100644 --- a/gdb/testsuite/gdb.dap/bt-nodebug.exp +++ b/gdb/testsuite/gdb.dap/bt-nodebug.exp @@ -44,6 +44,13 @@ lassign [dap_wait_for_event_and_check "stopped at function breakpoint" stopped \ "body hitBreakpointIds" $fn_bpno] unused objs # The bug was that this request would fail. -dap_check_request_and_response "backtrace" stackTrace {o threadId [i 1]} +set obj [dap_check_request_and_response "backtrace" \ + stackTrace {o threadId [i 1]}] +set frames [dict get [lindex $obj 0] body stackFrames] + +gdb_assert {[llength $frames] == 3} "three frames" + +gdb_assert {[dict get [lindex $frames 1] name] == "no_debug_info"} \ + "name of no-debug frame" dap_shutdown -- 2.30.2