def get_struct_definition(
struct_name: ScopedName,
identifier_manager: IdentifierManager) -> StructDefinition:
"""
Returns the struct definition of a struct given its full name (no alias resolution).
"""
struct_def = identifier_manager.get_by_full_name(struct_name)
if struct_def is None:
raise MissingIdentifierError(struct_name)
if not isinstance(struct_def, StructDefinition):
raise DefinitionError(f"""\
Expected '{struct_name}' to be a {StructDefinition.TYPE}. Found: '{struct_def.TYPE}'."""
)
return struct_def
class IdentifierCollector(Visitor):
"""
Collects all the identifiers in a code element.
Uses a partial visitor.
"""
# A dict from code element types to the identifier type they define.
IDENTIFIER_DEFINERS = {
CodeElementConst: ConstDefinition,
CodeElementLabel: LabelDefinition,
CodeElementReference: ReferenceDefinition,
CodeElementLocalVariable: ReferenceDefinition,
CodeElementTemporaryVariable: ReferenceDefinition,
CodeElementReturnValueReference: ReferenceDefinition,
}
def __init__(self):
super().__init__()
self.identifiers = IdentifierManager()
def add_identifier(self, name: ScopedName,
identifier_definition: IdentifierDefinition,
location: Optional[Location]):
"""
Adds an identifier with name 'name' and the given identifier definition at location
'location'.
"""
existing_definition = self.identifiers.get_by_full_name(name)
if existing_definition is not None:
if not isinstance(existing_definition, FutureIdentifierDefinition) or \
not isinstance(identifier_definition, FutureIdentifierDefinition):
raise PreprocessorError(f"Redefinition of '{name}'.",
location=location)
if (existing_definition.identifier_type,
identifier_definition.identifier_type) != (
ReferenceDefinition, ReferenceDefinition):
# Redefinition is only allowed in reference rebinding.
raise PreprocessorError(f"Redefinition of '{name}'.",
location=location)
self.identifiers.add_identifier(name, identifier_definition)
def add_future_identifier(self, name: ScopedName, identifier_type: type,
location: Optional[Location]):
"""
Adds a future identifier with name 'name' of type 'identifier_type' at location 'location'.
"""
self.add_identifier(name=name,
identifier_definition=FutureIdentifierDefinition(
identifier_type=identifier_type),
location=location)
def visit(self, obj):
if type(obj) in self.IDENTIFIER_DEFINERS:
definition_type = self.IDENTIFIER_DEFINERS[type(obj)]
identifier = _get_identifier(obj)
self.add_future_identifier(self.current_scope + identifier.name,
definition_type, identifier.location)
return super().visit(obj)
def _visit_default(self, obj):
assert isinstance(obj, (CodeBlock, CodeElement)), \
f'Received unexpected object of type {type(obj).__name__}.'
def visit_CodeElementFunction(self, elm: CodeElementFunction):
"""
Registers the function's identifier, arguments and return values, and then recursively
visits the code block contained in the function.
"""
function_scope = self.current_scope + elm.name
if elm.element_type == 'struct':
self.add_future_identifier(function_scope, StructDefinition,
elm.identifier.location)
return
args_scope = function_scope + CodeElementFunction.ARGUMENT_SCOPE
implicit_args_scope = function_scope + CodeElementFunction.IMPLICIT_ARGUMENT_SCOPE
rets_scope = function_scope + CodeElementFunction.RETURN_SCOPE
def handle_struct_def(identifier_list: Optional[IdentifierList],
struct_name: ScopedName):
location = elm.identifier.location
if identifier_list is not None:
location = identifier_list.location
self.add_future_identifier(name=struct_name,
identifier_type=StructDefinition,
location=location)
def handle_function_arguments(
identifier_list: Optional[IdentifierList],
struct_name: ScopedName):
handle_struct_def(identifier_list=identifier_list,
struct_name=struct_name)
if identifier_list is None:
return
for arg_id in identifier_list.identifiers:
if arg_id.name == N_LOCALS_CONSTANT:
raise PreprocessorError(
f"The name '{N_LOCALS_CONSTANT}' is reserved and cannot be used as an "
'argument name.',
location=arg_id.location)
# Within a function, arguments are also accessible directly.
self.add_future_identifier(function_scope + arg_id.name,
ReferenceDefinition,
arg_id.location)
handle_function_arguments(identifier_list=elm.arguments,
struct_name=args_scope)
handle_function_arguments(identifier_list=elm.implicit_arguments,
struct_name=implicit_args_scope)
handle_struct_def(identifier_list=elm.returns, struct_name=rets_scope)
# Make sure there is no name collision.
if elm.implicit_arguments is not None:
implicit_arg_names = {
arg_id.name
for arg_id in elm.implicit_arguments.identifiers
}
arg_and_return_identifiers = list(elm.arguments.identifiers)
if elm.returns is not None:
arg_and_return_identifiers += elm.returns.identifiers
for arg_id in arg_and_return_identifiers:
if arg_id.name in implicit_arg_names:
raise PreprocessorError(
'Arguments and return values cannot have the same name of an implicit '
'argument.',
location=arg_id.location)
self.add_future_identifier(function_scope, LabelDefinition,
elm.identifier.location)
# Add SIZEOF_LOCALS for current block at identifier definition location if available.
self.add_future_identifier(function_scope + N_LOCALS_CONSTANT,
ConstDefinition, elm.identifier.location)
super().visit_CodeElementFunction(elm)
def visit_CodeElementUnpackBinding(self, elm: CodeElementUnpackBinding):
"""
Registers all the unpacked identifiers.
"""
for identifier in elm.unpacking_list.identifiers:
if identifier.name == '_':
continue
self.add_future_identifier(self.current_scope + identifier.name,
ReferenceDefinition,
identifier.location)
def visit_CodeElementIf(self, obj: CodeElementIf):
assert obj.label_neq is not None
assert obj.label_end is not None
self.add_future_identifier(name=self.current_scope + obj.label_neq,
identifier_type=LabelDefinition,
location=obj.location)
self.add_future_identifier(name=self.current_scope + obj.label_end,
identifier_type=LabelDefinition,
location=obj.location)
self.visit(obj.main_code_block)
if obj.else_code_block is not None:
self.visit(obj.else_code_block)
def visit_CodeBlock(self, code_block: CodeBlock):
"""
Collects all identifiers in a code block.
"""
for elm in code_block.code_elements:
self.visit(elm.code_elm)
def visit_CodeElementImport(self, elm: CodeElementImport):
for import_item in elm.import_items:
alias_dst = ScopedName.from_string(
elm.path.name) + import_item.orig_identifier.name
local_identifier = import_item.identifier
# Ensure destination is a valid identifier.
if self.identifiers.get_by_full_name(alias_dst) is None:
raise PreprocessorError(
f"Scope '{elm.path.name}' does not include identifier "
f"'{import_item.orig_identifier.name}'.",
location=import_item.orig_identifier.location)
# Add alias to identifiers.
self.add_identifier(
name=self.current_scope + local_identifier.name,
identifier_definition=AliasDefinition(destination=alias_dst),
location=import_item.identifier.location)
def visit_CodeElementWith(self, elm: CodeElementWith):
for aliased_identifier in elm.identifiers:
if aliased_identifier.local_name is not None:
self.add_future_identifier(
name=self.current_scope +
aliased_identifier.local_name.name,
identifier_type=ReferenceDefinition,
location=aliased_identifier.local_name.location)
self.visit(elm.code_block)