diff options
author | Tom Tromey <tromey@adacore.com> | 2023-10-06 13:40:39 -0600 |
---|---|---|
committer | Tom Tromey <tromey@adacore.com> | 2023-11-17 07:09:36 -0700 |
commit | 1920148904fe5ca0035c1addf2376f9ab13ffd3d (patch) | |
tree | 69a13a377af5b457744e81be80a2f82aeb5581b5 | |
parent | 74affa1bc070ff0530b2a1b92d8d9fbcae6024ec (diff) | |
download | gdb-1920148904fe5ca0035c1addf2376f9ab13ffd3d.zip gdb-1920148904fe5ca0035c1addf2376f9ab13ffd3d.tar.gz gdb-1920148904fe5ca0035c1addf2376f9ab13ffd3d.tar.bz2 |
Handle StackFrameFormat in DAP
DAP specifies a StackFrameFormat object that can be used to change how
the "name" part of a stack frame is constructed. While this output
can already be done in a nicer way (and also letting the client choose
the formatting), nevertheless it is in the spec, so I figured I'd
implement it.
While implementing this, I discovered that the current code does not
correctly preserve frame IDs across requests. I rewrote frame
iteration to preserve this, and it turned out to be simpler to combine
these patches.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30475
-rw-r--r-- | gdb/python/lib/gdb/dap/bt.py | 110 | ||||
-rw-r--r-- | gdb/python/lib/gdb/dap/frames.py | 113 | ||||
-rw-r--r-- | gdb/python/lib/gdb/dap/scopes.py | 39 | ||||
-rw-r--r-- | gdb/testsuite/gdb.dap/stack-format.c | 41 | ||||
-rw-r--r-- | gdb/testsuite/gdb.dap/stack-format.exp | 133 | ||||
-rw-r--r-- | gdb/testsuite/gdb.dap/stack-format.py | 64 |
6 files changed, 453 insertions, 47 deletions
diff --git a/gdb/python/lib/gdb/dap/bt.py b/gdb/python/lib/gdb/dap/bt.py index 982d501..c63ca6d 100644 --- a/gdb/python/lib/gdb/dap/bt.py +++ b/gdb/python/lib/gdb/dap/bt.py @@ -16,37 +16,68 @@ import gdb import os -from gdb.frames import frame_iterator -from .frames import frame_id +# This is deprecated in 3.9, but required in older versions. +from typing import Optional + +from .frames import dap_frame_generator from .modules import module_id +from .scopes import symbol_value from .server import request, capability from .sources import make_source from .startup import send_gdb_with_response, in_gdb_thread from .state import set_thread +from .typecheck import type_check from .varref import apply_format +# Helper function to compute parameter information for a stack frame. +@in_gdb_thread +def _compute_parameters(frame, stack_format): + arg_iter = frame.frame_args() + if arg_iter is None: + return "" + result = [] + for arg in arg_iter: + desc = [] + name, val = symbol_value(arg, frame) + # We don't try to use any particular language's syntax for the + # output here. + if stack_format["parameterTypes"]: + desc.append("[" + str(val.type) + "]") + if stack_format["parameterNames"]: + desc.append(name) + # If both the name and the value are requested, insert an + # '=' for clarity. + if stack_format["parameterValues"]: + desc.append("=") + if stack_format["parameterValues"]: + desc.append(val.format_string(summary=True)) + result.append(" ".join(desc)) + return ", ".join(result) + + # Helper function to compute a stack trace. @in_gdb_thread -def _backtrace(thread_id, levels, startFrame, value_format): - with apply_format(value_format): +def _backtrace(thread_id, levels, startFrame, stack_format): + with apply_format(stack_format): set_thread(thread_id) frames = [] - if levels == 0: - # Zero means all remaining frames. - high = -1 - else: - # frame_iterator uses an inclusive range, so subtract one. - high = startFrame + levels - 1 - try: - frame_iter = frame_iterator(gdb.newest_frame(), startFrame, high) - except gdb.error: - frame_iter = () - for current_frame in frame_iter: + frame_iter = dap_frame_generator(startFrame, levels, stack_format["includeAll"]) + for frame_id, current_frame in frame_iter: pc = current_frame.address() + # The stack frame format affects the name, so we build it up + # piecemeal and assign it at the end. + name = current_frame.function() + # The meaning of StackFrameFormat.parameters was clarified + # in https://github.com/microsoft/debug-adapter-protocol/issues/411. + if stack_format["parameters"] and ( + stack_format["parameterTypes"] + or stack_format["parameterNames"] + or stack_format["parameterValues"] + ): + name += "(" + _compute_parameters(current_frame, stack_format) + ")" newframe = { - "id": frame_id(current_frame), - "name": current_frame.function(), + "id": frame_id, # This must always be supplied, but we will set it # correctly later if that is possible. "line": 0, @@ -54,15 +85,20 @@ def _backtrace(thread_id, levels, startFrame, value_format): "column": 0, "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 + if stack_format["line"]: + name += ", line " + str(line) + objfile = gdb.current_progspace().objfile_for_address(pc) + if objfile is not None: + newframe["moduleId"] = module_id(objfile) + if stack_format["module"]: + name += ", module " + objfile.username filename = current_frame.filename() if filename is not None: newframe["source"] = make_source(filename, os.path.basename(filename)) + newframe["name"] = name frames.append(newframe) # Note that we do not calculate totalFrames here. Its absence # tells the client that it may simply ask for frames until a @@ -72,11 +108,45 @@ def _backtrace(thread_id, levels, startFrame, value_format): } +# A helper function that checks the types of the elements of a +# StackFrameFormat, and converts this to a dict where all the members +# are set. This simplifies the implementation code a bit. +@type_check +def check_stack_frame( + *, + # Note that StackFrameFormat extends ValueFormat, which is why + # "hex" appears here. + hex: Optional[bool] = False, + parameters: Optional[bool] = False, + parameterTypes: Optional[bool] = False, + parameterNames: Optional[bool] = False, + parameterValues: Optional[bool] = False, + line: Optional[bool] = False, + module: Optional[bool] = False, + includeAll: Optional[bool] = False, + **rest +): + return { + "hex": hex, + "parameters": parameters, + "parameterTypes": parameterTypes, + "parameterNames": parameterNames, + "parameterValues": parameterValues, + "line": line, + "module": module, + "includeAll": includeAll, + } + + @request("stackTrace") @capability("supportsDelayedStackTraceLoading") def stacktrace( *, levels: int = 0, startFrame: int = 0, threadId: int, format=None, **extra ): + # It's simpler if the format is always set. + if format is None: + format = {} + format = check_stack_frame(**format) return send_gdb_with_response( lambda: _backtrace(threadId, levels, startFrame, format) ) diff --git a/gdb/python/lib/gdb/dap/frames.py b/gdb/python/lib/gdb/dap/frames.py index 1d2d137..669e73f 100644 --- a/gdb/python/lib/gdb/dap/frames.py +++ b/gdb/python/lib/gdb/dap/frames.py @@ -14,6 +14,9 @@ # along with this program. If not, see <http://www.gnu.org/licenses/>. import gdb +import itertools + +from gdb.frames import frame_iterator from .startup import in_gdb_thread @@ -24,11 +27,17 @@ from .startup import in_gdb_thread _all_frames = [] +# Map from a global thread ID to a memoizing frame iterator. +_iter_map = {} + + # Clear all the frame IDs. @in_gdb_thread def _clear_frame_ids(evt): global _all_frames _all_frames = [] + global _iter_map + _iter_map = {} # Clear the frame ID map whenever the inferior runs. @@ -36,18 +45,6 @@ gdb.events.cont.connect(_clear_frame_ids) @in_gdb_thread -def frame_id(frame): - """Return the frame identifier for FRAME.""" - global _all_frames - for i in range(0, len(_all_frames)): - if _all_frames[i] == frame: - return i - result = len(_all_frames) - _all_frames.append(frame) - return result - - -@in_gdb_thread def frame_for_id(id): """Given a frame identifier ID, return the corresponding frame.""" global _all_frames @@ -59,3 +56,95 @@ def select_frame(id): """Given a frame identifier ID, select the corresponding frame.""" frame = frame_for_id(id) frame.inferior_frame().select() + + +# A simple memoizing iterator. Note that this is not very robust. +# For example, you can't start two copies of the iterator and then +# alternate fetching items from each. Instead, it implements just +# what is needed for the current callers. +class _MemoizingIterator: + def __init__(self, iterator): + self.iterator = iterator + self.seen = [] + + def __iter__(self): + # First the memoized items. + for item in self.seen: + yield item + # Now memoize new items. + for item in self.iterator: + self.seen.append(item) + yield item + + +# A generator that fetches frames and pairs them with a frame ID. It +# yields tuples of the form (ID, ELIDED, FRAME), where ID is the +# generated ID, ELIDED is a boolean indicating if the frame should be +# elided, and FRAME is the frame itself. This approach lets us +# memoize the result and assign consistent IDs, independent of how +# "includeAll" is set in the request. +@in_gdb_thread +def _frame_id_generator(): + try: + base_iterator = frame_iterator(gdb.newest_frame(), 0, -1) + except gdb.error: + base_iterator = () + + # Helper function to assign an ID to a frame. + def get_id(frame): + global _all_frames + num = len(_all_frames) + _all_frames.append(frame) + return num + + def yield_frames(iterator, for_elided): + for frame in iterator: + # Unfortunately the frame filter docs don't describe + # whether the elided frames conceptually come before or + # after the eliding frame. Here we choose after. + yield (get_id(frame), for_elided, frame) + + elided = frame.elided() + if elided is not None: + yield from yield_frames(frame.elided(), True) + + yield from yield_frames(base_iterator, False) + + +# Return the memoizing frame iterator for the selected thread. +@in_gdb_thread +def _get_frame_iterator(): + thread_id = gdb.selected_thread().global_num + global _iter_map + if thread_id not in _iter_map: + _iter_map[thread_id] = _MemoizingIterator(_frame_id_generator()) + return _iter_map[thread_id] + + +# A helper function that creates an iterable that returns (ID, FRAME) +# pairs. It uses the memoizing frame iterator, but also handles the +# "includeAll" member of StackFrameFormat. +@in_gdb_thread +def dap_frame_generator(frame_low, levels, include_all): + """A generator that yields identifiers and frames. + + Each element is a pair of the form (ID, FRAME). + ID is the internally-assigned frame ID. + FRAME is a FrameDecorator of some kind. + + Arguments are as to the stackTrace request.""" + + base_iterator = _get_frame_iterator() + + if not include_all: + base_iterator = itertools.filterfalse(lambda item: item[1], base_iterator) + + if levels == 0: + # Zero means all remaining frames. + frame_high = None + else: + frame_high = frame_low + levels + base_iterator = itertools.islice(base_iterator, frame_low, frame_high) + + for ident, _, frame in base_iterator: + yield (ident, frame) diff --git a/gdb/python/lib/gdb/dap/scopes.py b/gdb/python/lib/gdb/dap/scopes.py index 13c3581..e526dfb 100644 --- a/gdb/python/lib/gdb/dap/scopes.py +++ b/gdb/python/lib/gdb/dap/scopes.py @@ -36,6 +36,29 @@ def clear_scopes(event): gdb.events.cont.connect(clear_scopes) +# A helper function to compute the value of a symbol. SYM is either a +# gdb.Symbol, or an object implementing the SymValueWrapper interface. +# FRAME is a frame wrapper, as produced by a frame filter. Returns a +# tuple of the form (NAME, VALUE), where NAME is the symbol's name and +# VALUE is a gdb.Value. +@in_gdb_thread +def symbol_value(sym, frame): + inf_frame = frame.inferior_frame() + # Make sure to select the frame first. Ideally this would not + # be needed, but this is a way to set the current language + # properly so that language-dependent APIs will work. + inf_frame.select() + name = str(sym.symbol()) + val = sym.value() + if val is None: + # No synthetic value, so must read the symbol value + # ourselves. + val = sym.symbol().value(inf_frame) + elif not isinstance(val, gdb.Value): + val = gdb.Value(val) + return (name, val) + + class _ScopeReference(BaseReference): def __init__(self, name, hint, frame, var_list): super().__init__(name) @@ -67,21 +90,7 @@ class _ScopeReference(BaseReference): @in_gdb_thread def fetch_one_child(self, idx): - # Make sure to select the frame first. Ideally this would not - # be needed, but this is a way to set the current language - # properly so that language-dependent APIs will work. - self.inf_frame.select() - # Here SYM will conform to the SymValueWrapper interface. - sym = self.var_list[idx] - name = str(sym.symbol()) - val = sym.value() - if val is None: - # No synthetic value, so must read the symbol value - # ourselves. - val = sym.symbol().value(self.inf_frame) - elif not isinstance(val, gdb.Value): - val = gdb.Value(val) - return (name, val) + return symbol_value(self.var_list[idx], self.frame) class _RegisterReference(_ScopeReference): diff --git a/gdb/testsuite/gdb.dap/stack-format.c b/gdb/testsuite/gdb.dap/stack-format.c new file mode 100644 index 0000000..80759e5 --- /dev/null +++ b/gdb/testsuite/gdb.dap/stack-format.c @@ -0,0 +1,41 @@ +/* Copyright 2023 Free Software Foundation, Inc. + + This file is part of GDB. + + 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/>. */ + +int function (int x, char y) +{ + return y - x - 1; /* BREAK */ +} + +int z_1 (int x, char y) +{ + return function (x, y); +} + +int z_2 (int x, char y) +{ + return z_1 (x, y); +} + +int z_3 (int x, char y) +{ + return z_2 (x, y); +} + +int main () +{ + return z_3 (64, 'A'); +} diff --git a/gdb/testsuite/gdb.dap/stack-format.exp b/gdb/testsuite/gdb.dap/stack-format.exp new file mode 100644 index 0000000..caa1266 --- /dev/null +++ b/gdb/testsuite/gdb.dap/stack-format.exp @@ -0,0 +1,133 @@ +# 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/>. + +# Test DAP stack format options. + +require allow_dap_tests + +load_lib dap-support.exp + +standard_testfile + +if {[build_executable ${testfile}.exp $testfile] == -1} { + return +} + +set remote_python_file [gdb_remote_download host \ + ${srcdir}/${subdir}/${testfile}.py] + +save_vars GDBFLAGS { + append GDBFLAGS " -iex \"source $remote_python_file\"" + + if {[dap_launch $testfile] == ""} { + return + } +} + +set line [gdb_get_line_number "BREAK"] +set obj [dap_check_request_and_response "set breakpoint by line number" \ + setBreakpoints \ + [format {o source [o path [%s]] breakpoints [a [o line [i %d]]]} \ + [list s $srcfile] $line]] +set line_bpno [dap_get_breakpoint_number $obj] + +dap_check_request_and_response "start inferior" configurationDone + +dap_wait_for_event_and_check "stopped at line breakpoint" stopped \ + "body reason" breakpoint \ + "body hitBreakpointIds" $line_bpno + + +# Each request should return the same frame ID. Store it here, +# indexed by requested frame. +array set frame_id {} + +# Request a single frame of the stack trace and check it. NAME is the +# name of the test. FRAME is the number of the frame to request. +# FORMAT is contents of the StackFrameFormat object to use. It is in +# TON form. EXPECTED is the expected 'name' value of the resulting +# frame. If REGEXP is set, then EXPECTED is a regular expression; +# otherwise it is treated as the exact string result. +proc check_stack_frame {name frame format expected {regexp 0}} { + with_test_prefix $name { + set args [format {o startFrame [i %d] levels [i 1] threadId [i 1]} \ + $frame] + if {$format != ""} { + append args " format \[o $format\]" + } + + set bt [lindex [dap_check_request_and_response "backtrace" \ + stackTrace $args] \ + 0] + set frame_info [lindex [dict get $bt body stackFrames] 0] + + # Each request at this level should return the same frame ID. + set this_id [dict get $frame_info id] + global frame_id + if {[info exists frame_id($frame)]} { + gdb_assert {$frame_id($frame) == $this_id} "unchanging frame id" + } else { + set frame_id($frame) $this_id + } + + if {$regexp} { + gdb_assert {[regexp $expected [dict get $frame_info name]]} \ + "got expected name" + } else { + gdb_assert {[dict get $frame_info name] == $expected} \ + "got expected name" + } + } +} + +check_stack_frame empty 0 {} "function" + +check_stack_frame parameters 0 {parameters [l true] \ + parameterTypes [l true] \ + parameterNames [l true] \ + parameterValues [l true]} \ + {function([int] x = 64, [char] y = 65 'A')} + +# When 'parameters' is false, it disables the other parameter* +# options. This was clarified in +# https://github.com/microsoft/debug-adapter-protocol/issues/411 +check_stack_frame noparams 0 {parameters [l false] \ + parameterTypes [l true] \ + parameterNames [l true] \ + parameterValues [l true]} \ + "function" + +check_stack_frame line 0 {line [l true] module [l true]} \ + "function, line $line, module .*stack-format" \ + 1 + +check_stack_frame hex 0 \ + {parameters [l true] parameterValues [l true] hex [l true]} \ + "function(0x40, 0x41)" + +check_stack_frame elided-main 1 {} "main" + +# The next requests will ask for all frames, so the old frame 1 will +# be the new frame 4. Update the map to check this. +set frame_id(4) $frame_id(1) +unset frame_id(1) + +check_stack_frame no-elide 0 {includeAll [l true]} "function" +check_stack_frame z-frame-1 1 {includeAll [l true]} "z_1" +check_stack_frame z-frame-2 2 {includeAll [l true]} "z_2" +check_stack_frame z-frame-3 3 {includeAll [l true]} "z_3" +check_stack_frame main-include-all 4 {includeAll [l true]} "main" + +dap_shutdown diff --git a/gdb/testsuite/gdb.dap/stack-format.py b/gdb/testsuite/gdb.dap/stack-format.py new file mode 100644 index 0000000..b15cb8a --- /dev/null +++ b/gdb/testsuite/gdb.dap/stack-format.py @@ -0,0 +1,64 @@ +# Copyright (C) 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 +import itertools + +from gdb.FrameDecorator import DAPFrameDecorator + + +class ElidingFrameDecorator(DAPFrameDecorator): + def __init__(self, frame, elided_frames): + super(ElidingFrameDecorator, self).__init__(frame) + self.elided_frames = elided_frames + + def elided(self): + return iter(self.elided_frames) + + +class ElidingIterator: + def __init__(self, ii): + self.input_iterator = ii + + def __iter__(self): + return self + + def __next__(self): + frame = next(self.input_iterator) + if str(frame.function()) != "function": + return frame + + # Elide the next three frames. + elided = [] + elided.append(next(self.input_iterator)) + elided.append(next(self.input_iterator)) + elided.append(next(self.input_iterator)) + + return ElidingFrameDecorator(frame, elided) + + +class FrameElider: + def __init__(self): + self.name = "Elider" + self.priority = 900 + self.enabled = True + gdb.frame_filters[self.name] = self + + def filter(self, frame_iter): + return ElidingIterator(frame_iter) + + +FrameElider() |