This patch implements the DAP setVariable request.
setVariable is a bit odd in that it specifies the variable to modify
by passing in the variable's container and the name of the variable.
This approach can't handle variable shadowing (there are a couple of
open DAP bugs on this topic), so this patch renames duplicates to
avoid the problem.
return send_gdb_with_response(
lambda: _set_expression(expression, value, frameId, format)
)
+
+
+# Helper function to perform an assignment.
+@in_gdb_thread
+def _set_variable(ref, name, value, value_format):
+ with apply_format(value_format):
+ var = find_variable(ref)
+ lhs = var.find_child_by_name(name)
+ rhs = gdb.parse_and_eval(value)
+ lhs.assign(rhs)
+ return lhs.to_object()
+
+
+@capability("supportsSetVariable")
+@request("setVariable")
+def set_variable(
+ *, variablesReference: int, name: str, value: str, format=None, **args
+):
+ return send_gdb_with_response(
+ lambda: _set_variable(variablesReference, name, value, format)
+ )
# FIXME construct a Source object
return result
+ def has_children(self):
+ return True
+
def child_count(self):
return len(self.var_list)
import gdb
from .startup import in_gdb_thread
from .server import client_bool_capability
-from abc import abstractmethod
+from abc import ABC, abstractmethod
+from collections import defaultdict
from contextlib import contextmanager
return _null()
-class BaseReference:
+class BaseReference(ABC):
"""Represent a variable or a scope.
This class is just a base class, some methods must be implemented in
all_variables.append(self)
self.ref = len(all_variables)
self.name = name
- self.children = None
+ self.reset_children()
@in_gdb_thread
def to_object(self):
The resulting object is a starting point that can be filled in
further. See the Scope or Variable types in the spec"""
- result = {
- "variablesReference": self.ref,
- }
+ result = {"variablesReference": self.ref if self.has_children() else 0}
if self.name is not None:
result["name"] = str(self.name)
return result
- def no_children(self):
- """Call this to declare that this variable or scope has no children."""
- self.ref = 0
+ @abstractmethod
+ def has_children(self):
+ """Return True if this object has children."""
+ return False
+
+ def reset_children(self):
+ """Reset any cached information about the children of this object."""
+ # A list of all the children. Each child is a BaseReference
+ # of some kind.
+ self.children = None
+ # Map from the name of a child to a BaseReference.
+ self.by_name = {}
+ # Keep track of how many duplicates there are of a given name,
+ # so that unique names can be generated. Map from base name
+ # to a count.
+ self.name_counts = defaultdict(lambda: 1)
@abstractmethod
def fetch_one_child(self, index):
"""Return the number of children of this variable."""
return
+ # Helper method to compute the final name for a child whose base
+ # name is given. Updates the name_counts map. This is used to
+ # handle shadowing -- in DAP, the adapter is responsible for
+ # making sure that all the variables in a a given container have
+ # unique names. See
+ # https://github.com/microsoft/debug-adapter-protocol/issues/141
+ # and
+ # https://github.com/microsoft/debug-adapter-protocol/issues/149
+ def _compute_name(self, name):
+ if name in self.by_name:
+ self.name_counts[name] += 1
+ # In theory there's no safe way to compute a name, because
+ # a pretty-printer might already be generating names of
+ # that form. In practice I think we should not worry too
+ # much.
+ name = name + " #" + str(self.name_counts[name])
+ return name
+
@in_gdb_thread
def fetch_children(self, start, count):
"""Fetch children of this variable.
START is the starting index.
- COUNT is the number to return, with 0 meaning return all."""
+ COUNT is the number to return, with 0 meaning return all.
+ Returns an iterable of some kind."""
if count == 0:
count = self.child_count()
if self.children is None:
self.children = [None] * self.child_count()
- result = []
for idx in range(start, start + count):
if self.children[idx] is None:
(name, value) = self.fetch_one_child(idx)
- self.children[idx] = VariableReference(name, value)
- result.append(self.children[idx])
- return result
+ name = self._compute_name(name)
+ var = VariableReference(name, value)
+ self.children[idx] = var
+ self.by_name[name] = var
+ yield self.children[idx]
+
+ @in_gdb_thread
+ def find_child_by_name(self, name):
+ """Find a child of this variable, given its name.
+
+ Returns the value of the child, or throws if not found."""
+ # A lookup by name can only be done using names previously
+ # provided to the client, so we can simply rely on the by-name
+ # map here.
+ if name in self.by_name:
+ return self.by_name[name]
+ raise Exception("no variable named '" + name + "'")
class VariableReference(BaseReference):
RESULT_NAME can be used to change how the simple string result
is emitted in the result dictionary."""
super().__init__(name)
- self.value = value
- self.printer = gdb.printing.make_visualizer(value)
self.result_name = result_name
- # We cache all the children we create.
+ self.value = value
+ self._update_value()
+
+ # Internal method to update local data when the value changes.
+ def _update_value(self):
+ self.reset_children()
+ self.printer = gdb.printing.make_visualizer(self.value)
self.child_cache = None
- if not hasattr(self.printer, "children"):
- self.no_children()
- self.count = None
- else:
+ if self.has_children():
self.count = -1
+ else:
+ self.count = None
+
+ def assign(self, value):
+ """Assign VALUE to this object and update."""
+ self.value.assign(value)
+ self._update_value()
+
+ def has_children(self):
+ return hasattr(self.printer, "children")
def cache_children(self):
if self.child_cache is None:
--- /dev/null
+/* 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/>. */
+
+struct special_type
+{
+ /* Discriminator used by the pretty-printer. When zero, no fields
+ are shown; when non-zero, shows the datum. */
+ int disc;
+ int datum;
+};
+
+struct special_type empty = { 0, 23 };
+struct special_type full = { 1, 23 };
+
+int
+main ()
+{
+ struct special_type value = full;
+
+ return 0; /* STOP */
+}
--- /dev/null
+# 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 the setVariable request.
+
+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 "STOP"]
+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
+
+set bt [lindex [dap_check_request_and_response "backtrace" stackTrace \
+ {o threadId [i 1]}] \
+ 0]
+set frame_id [dict get [lindex [dict get $bt body stackFrames] 0] id]
+
+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]
+
+lassign $scopes scope reg_scope
+gdb_assert {[dict get $scope name] == "Locals"} "scope is locals"
+gdb_assert {[dict get $scope namedVariables] == 1} "one var in scope"
+
+set num [dict get $scope variablesReference]
+set refs [lindex [dap_check_request_and_response "fetch variable" \
+ "variables" \
+ [format {o variablesReference [i %d] count [i 1]} \
+ $num]] \
+ 0]
+
+set desc [dict get $refs body variables]
+gdb_assert {[llength $desc] == 1} "only one variable fetched"
+set desc [lindex $desc 0]
+
+set saved_ref [dict get $desc variablesReference]
+
+proc check_vars {prefix var varref summary} {
+ with_test_prefix $prefix {
+ gdb_assert {[dict get $var name] == "value"} "variable name"
+ gdb_assert {[dict get $var variablesReference] == $varref} \
+ "variable reference"
+ gdb_assert {[dict get $var value] == $summary} \
+ "variable value"
+ }
+}
+
+check_vars initial $desc $saved_ref full
+
+set refs [lindex [dap_check_request_and_response "assign empty to variable" \
+ "setVariable" \
+ [format {o variablesReference [i %d] name [s value] \
+ value [s empty]} \
+ $num]] \
+ 0]
+check_vars "assign empty" [dict get $refs body] 0 empty
+
+set refs [lindex [dap_check_request_and_response "assign full to variable" \
+ "setVariable" \
+ [format {o variablesReference [i %d] name [s value] \
+ value [s full]} \
+ $num]] \
+ 0]
+check_vars "assign full" [dict get $refs body] $saved_ref full
+
+# Now fetch the children of the variable, to check that the shadowing
+# workaround works.
+gdb_assert {[dict get $refs body namedVariables] == 2} \
+ "two children of variable"
+
+set num [dict get $refs body variablesReference]
+set refs [lindex [dap_check_request_and_response \
+ "fetch children of variable" "variables" \
+ [format {o variablesReference [i %d] count [i 2]} \
+ $num]] \
+ 0]
+
+lassign [dict get $refs body variables] one two
+gdb_assert {[dict get $one name] != [dict get $two name]} \
+ "children have different names"
+
+dap_shutdown
--- /dev/null
+# Copyright (C) 2022-2023 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
+
+
+class EmptyPrinter(gdb.ValuePrinter):
+ """Pretty print a structure"""
+
+ def __init__(self, val):
+ self._val = val
+
+ def to_string(self):
+ return "empty"
+
+
+class FullPrinter(gdb.ValuePrinter):
+ """Pretty print a structure"""
+
+ def __init__(self, val):
+ self._val = val
+
+ def to_string(self):
+ return "full"
+
+ def children(self):
+ # This is used to test the renaming code.
+ yield "datum", self._val["datum"]
+ yield "datum", self._val["datum"]
+
+
+def lookup_function(val):
+ if val.type.tag == "special_type":
+ if val["disc"] == 0:
+ return EmptyPrinter(val)
+ else:
+ return FullPrinter(val)
+ return None
+
+
+gdb.pretty_printers.append(lookup_function)
projects / binutils-gdb.git / commitdiff