| # 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 |
| from .startup import in_gdb_thread |
| from abc import abstractmethod |
| |
| |
| # A list of all the variable references created during this pause. |
| all_variables = [] |
| |
| |
| # When the inferior is re-started, we erase all variable references. |
| # See the section "Lifetime of Objects References" in the spec. |
| @in_gdb_thread |
| def clear_vars(event): |
| global all_variables |
| all_variables = [] |
| |
| |
| gdb.events.cont.connect(clear_vars) |
| |
| |
| class BaseReference: |
| """Represent a variable or a scope. |
| |
| This class is just a base class, some methods must be implemented in |
| subclasses. |
| |
| The 'ref' field can be used as the variablesReference in the protocol. |
| """ |
| |
| @in_gdb_thread |
| def __init__(self, name): |
| """Create a new variable reference with the given name. |
| |
| NAME is a string or None. None means this does not have a |
| name, e.g., the result of expression evaluation.""" |
| |
| global all_variables |
| all_variables.append(self) |
| self.ref = len(all_variables) |
| self.name = name |
| self.children = None |
| |
| @in_gdb_thread |
| def to_object(self): |
| """Return a dictionary that describes this object for DAP. |
| |
| 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, |
| } |
| if self.name is not None: |
| result["name"] = 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 fetch_one_child(self, index): |
| """Fetch one child of this variable. |
| |
| INDEX is the index of the child to fetch. |
| This should return a tuple of the form (NAME, VALUE), where |
| NAME is the name of the variable, and VALUE is a gdb.Value.""" |
| return |
| |
| @abstractmethod |
| def child_count(self): |
| """Return the number of children of this variable.""" |
| return |
| |
| @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.""" |
| 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 |
| |
| |
| class VariableReference(BaseReference): |
| """Concrete subclass of BaseReference that handles gdb.Value.""" |
| |
| def __init__(self, name, value, result_name="value"): |
| """Initializer. |
| |
| NAME is the name of this reference, see superclass. |
| VALUE is a gdb.Value that holds the value. |
| 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.child_cache = None |
| if not hasattr(self.printer, "children"): |
| self.no_children() |
| self.count = None |
| else: |
| self.count = -1 |
| |
| def cache_children(self): |
| if self.child_cache is None: |
| # This discards all laziness. This could be improved |
| # slightly by lazily evaluating children, but because this |
| # code also generally needs to know the number of |
| # children, it probably wouldn't help much. A real fix |
| # would require an update to gdb's pretty-printer protocol |
| # (though of course that is probably also inadvisable). |
| self.child_cache = list(self.printer.children()) |
| return self.child_cache |
| |
| def child_count(self): |
| if self.count is None: |
| return None |
| if self.count == -1: |
| if hasattr(self.printer, "num_children"): |
| num_children = self.printer.num_children |
| else: |
| num_children = len(self.cache_children()) |
| self.count = num_children |
| return self.count |
| |
| def to_object(self): |
| result = super().to_object() |
| result[self.result_name] = self.printer.to_string() |
| num_children = self.child_count() |
| if num_children is not None: |
| if ( |
| hasattr(self.printer, "display_hint") |
| and self.printer.display_hint() == "array" |
| ): |
| result["indexedVariables"] = num_children |
| else: |
| result["namedVariables"] = num_children |
| if self.value.type.code == gdb.TYPE_CODE_PTR: |
| result["memoryReference"] = hex(int(self.value)) |
| elif self.value.address is not None: |
| result["memoryReference"] = hex(int(self.value.address)) |
| return result |
| |
| @in_gdb_thread |
| def fetch_one_child(self, idx): |
| return self.cache_children()[idx] |
| |
| |
| @in_gdb_thread |
| def find_variable(ref): |
| """Given a variable reference, return the corresponding variable object.""" |
| global all_variables |
| # Variable references are offset by 1. |
| ref = ref - 1 |
| if ref < 0 or ref > len(all_variables): |
| raise Exception("invalid variablesReference") |
| return all_variables[ref] |
