| 123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235 |
- # mako/pyparser.py
- # Copyright 2006-2025 the Mako authors and contributors <see AUTHORS file>
- #
- # This module is part of Mako and is released under
- # the MIT License: http://www.opensource.org/licenses/mit-license.php
- """Handles parsing of Python code.
- Parsing to AST is done via _ast on Python > 2.5, otherwise the compiler
- module is used.
- """
- import operator
- import _ast
- from mako import _ast_util
- from mako import compat
- from mako import exceptions
- from mako import util
- # words that cannot be assigned to (notably
- # smaller than the total keys in __builtins__)
- reserved = {"True", "False", "None", "print"}
- # the "id" attribute on a function node
- arg_id = operator.attrgetter("arg")
- util.restore__ast(_ast)
- def parse(code, mode="exec", **exception_kwargs):
- """Parse an expression into AST"""
- try:
- return _ast_util.parse(code, "<unknown>", mode)
- except Exception as e:
- raise exceptions.SyntaxException(
- "(%s) %s (%r)"
- % (
- compat.exception_as().__class__.__name__,
- compat.exception_as(),
- code[0:50],
- ),
- **exception_kwargs,
- ) from e
- class FindIdentifiers(_ast_util.NodeVisitor):
- def __init__(self, listener, **exception_kwargs):
- self.in_function = False
- self.in_assign_targets = False
- self.local_ident_stack = set()
- self.listener = listener
- self.exception_kwargs = exception_kwargs
- def _add_declared(self, name):
- if not self.in_function:
- self.listener.declared_identifiers.add(name)
- else:
- self.local_ident_stack.add(name)
- def visit_ClassDef(self, node):
- self._add_declared(node.name)
- def visit_Assign(self, node):
- # flip around the visiting of Assign so the expression gets
- # evaluated first, in the case of a clause like "x=x+5" (x
- # is undeclared)
- self.visit(node.value)
- in_a = self.in_assign_targets
- self.in_assign_targets = True
- for n in node.targets:
- self.visit(n)
- self.in_assign_targets = in_a
- def visit_ExceptHandler(self, node):
- if node.name is not None:
- self._add_declared(node.name)
- if node.type is not None:
- self.visit(node.type)
- for statement in node.body:
- self.visit(statement)
- def visit_Lambda(self, node, *args):
- self._visit_function(node, True)
- def visit_FunctionDef(self, node):
- self._add_declared(node.name)
- self._visit_function(node, False)
- def visit_ListComp(self, node):
- if self.in_function:
- for comp in node.generators:
- self.visit(comp.target)
- self.visit(comp.iter)
- else:
- self.generic_visit(node)
- visit_SetComp = visit_GeneratorExp = visit_ListComp
- def visit_DictComp(self, node):
- if self.in_function:
- for comp in node.generators:
- self.visit(comp.target)
- self.visit(comp.iter)
- else:
- self.generic_visit(node)
- def _expand_tuples(self, args):
- for arg in args:
- if isinstance(arg, _ast.Tuple):
- yield from arg.elts
- else:
- yield arg
- def _visit_function(self, node, islambda):
- # push function state onto stack. dont log any more
- # identifiers as "declared" until outside of the function,
- # but keep logging identifiers as "undeclared". track
- # argument names in each function header so they arent
- # counted as "undeclared"
- inf = self.in_function
- self.in_function = True
- local_ident_stack = self.local_ident_stack
- self.local_ident_stack = local_ident_stack.union(
- [arg_id(arg) for arg in self._expand_tuples(node.args.args)]
- )
- if islambda:
- self.visit(node.body)
- else:
- for n in node.body:
- self.visit(n)
- self.in_function = inf
- self.local_ident_stack = local_ident_stack
- def visit_For(self, node):
- # flip around visit
- self.visit(node.iter)
- self.visit(node.target)
- for statement in node.body:
- self.visit(statement)
- for statement in node.orelse:
- self.visit(statement)
- def visit_Name(self, node):
- if isinstance(node.ctx, _ast.Store):
- # this is eqiuvalent to visit_AssName in
- # compiler
- self._add_declared(node.id)
- elif (
- node.id not in reserved
- and node.id not in self.listener.declared_identifiers
- and node.id not in self.local_ident_stack
- ):
- self.listener.undeclared_identifiers.add(node.id)
- def visit_Import(self, node):
- for name in node.names:
- if name.asname is not None:
- self._add_declared(name.asname)
- else:
- self._add_declared(name.name.split(".")[0])
- def visit_ImportFrom(self, node):
- for name in node.names:
- if name.asname is not None:
- self._add_declared(name.asname)
- elif name.name == "*":
- raise exceptions.CompileException(
- "'import *' is not supported, since all identifier "
- "names must be explicitly declared. Please use the "
- "form 'from <modulename> import <name1>, <name2>, "
- "...' instead.",
- **self.exception_kwargs,
- )
- else:
- self._add_declared(name.name)
- class FindTuple(_ast_util.NodeVisitor):
- def __init__(self, listener, code_factory, **exception_kwargs):
- self.listener = listener
- self.exception_kwargs = exception_kwargs
- self.code_factory = code_factory
- def visit_Tuple(self, node):
- for n in node.elts:
- p = self.code_factory(n, **self.exception_kwargs)
- self.listener.codeargs.append(p)
- self.listener.args.append(ExpressionGenerator(n).value())
- ldi = self.listener.declared_identifiers
- self.listener.declared_identifiers = ldi.union(
- p.declared_identifiers
- )
- lui = self.listener.undeclared_identifiers
- self.listener.undeclared_identifiers = lui.union(
- p.undeclared_identifiers
- )
- class ParseFunc(_ast_util.NodeVisitor):
- def __init__(self, listener, **exception_kwargs):
- self.listener = listener
- self.exception_kwargs = exception_kwargs
- def visit_FunctionDef(self, node):
- self.listener.funcname = node.name
- argnames = [arg_id(arg) for arg in node.args.args]
- if node.args.vararg:
- argnames.append(node.args.vararg.arg)
- kwargnames = [arg_id(arg) for arg in node.args.kwonlyargs]
- if node.args.kwarg:
- kwargnames.append(node.args.kwarg.arg)
- self.listener.argnames = argnames
- self.listener.defaults = node.args.defaults # ast
- self.listener.kwargnames = kwargnames
- self.listener.kwdefaults = node.args.kw_defaults
- self.listener.varargs = node.args.vararg
- self.listener.kwargs = node.args.kwarg
- class ExpressionGenerator:
- def __init__(self, astnode):
- self.generator = _ast_util.SourceGenerator(" " * 4)
- self.generator.visit(astnode)
- def value(self):
- return "".join(self.generator.result)
|