"""Compiles nodes from the parser into Python code."""
from collections import namedtuple
from functools import update_wrapper
from io import StringIO
from itertools import chain
from keyword import iskeyword as is_python_keyword

from markupsafe import escape
from markupsafe import Markup

from . import nodes
from .exceptions import TemplateAssertionError
from .idtracking import Symbols
from .idtracking import VAR_LOAD_ALIAS
from .idtracking import VAR_LOAD_PARAMETER
from .idtracking import VAR_LOAD_RESOLVE
from .idtracking import VAR_LOAD_UNDEFINED
from .nodes import EvalContext
from .optimizer import Optimizer
from .utils import concat
from .visitor import NodeVisitor

operators = {
    "eq": "==",
    "ne": "!=",
    "gt": ">",
    "gteq": ">=",
    "lt": "<",
    "lteq": "<=",
    "in": "in",
    "notin": "not in",
}


def optimizeconst(f):
    def new_func(self, node, frame, **kwargs):
        # Only optimize if the frame is not volatile
        if self.optimized and not frame.eval_ctx.volatile:
            new_node = self.optimizer.visit(node, frame.eval_ctx)
            if new_node != node:
                return self.visit(new_node, frame)
        return f(self, node, frame, **kwargs)

    return update_wrapper(new_func, f)


def generate(
    node, environment, name, filename, stream=None, defer_init=False, optimized=True
):
    """Generate the python source for a node tree."""
    if not isinstance(node, nodes.Template):
        raise TypeError("Can't compile non template nodes")
    generator = environment.code_generator_class(
        environment, name, filename, stream, defer_init, optimized
    )
    generator.visit(node)
    if stream is None:
        return generator.stream.getvalue()


def has_safe_repr(value):
    """Does the node have a safe representation?"""
    if value is None or value is NotImplemented or value is Ellipsis:
        return True

    if type(value) in {bool, int, float, complex, range, str, Markup}:
        return True

    if type(value) in {tuple, list, set, frozenset}:
        return all(has_safe_repr(v) for v in value)

    if type(value) is dict:
        return all(has_safe_repr(k) and has_safe_repr(v) for k, v in value.items())

    return False


def find_undeclared(nodes, names):
    """Check if the names passed are accessed undeclared.  The return value
    is a set of all the undeclared names from the sequence of names found.
    """
    visitor = UndeclaredNameVisitor(names)
    try:
        for node in nodes:
            visitor.visit(node)
    except VisitorExit:
        pass
    return visitor.undeclared


class MacroRef:
    def __init__(self, node):
        self.node = node
        self.accesses_caller = False
        self.accesses_kwargs = False
        self.accesses_varargs = False


class Frame:
    """Holds compile time information for us."""

    def __init__(self, eval_ctx, parent=None, level=None):
        self.eval_ctx = eval_ctx
        self.symbols = Symbols(parent.symbols if parent else None, level=level)

        # a toplevel frame is the root + soft frames such as if conditions.
        self.toplevel = False

        # the root frame is basically just the outermost frame, so no if
        # conditions.  This information is used to optimize inheritance
        # situations.
        self.rootlevel = False

        # in some dynamic inheritance situations the compiler needs to add
        # write tests around output statements.
        self.require_output_check = parent and parent.require_output_check

        # inside some tags we are using a buffer rather than yield statements.
        # this for example affects {% filter %} or {% macro %}.  If a frame
        # is buffered this variable points to the name of the list used as
        # buffer.
        self.buffer = None

        # the name of the block we're in, otherwise None.
        self.block = parent.block if parent else None

        # the parent of this frame
        self.parent = parent

        if parent is not None:
            self.buffer = parent.buffer

    def copy(self):
        """Create a copy of the current one."""
        rv = object.__new__(self.__class__)
        rv.__dict__.update(self.__dict__)
        rv.symbols = self.symbols.copy()
        return rv

    def inner(self, isolated=False):
        """Return an inner frame."""
        if isolated:
            return Frame(self.eval_ctx, level=self.symbols.level + 1)
        return Frame(self.eval_ctx, self)

    def soft(self):
        """Return a soft frame.  A soft frame may not be modified as
        standalone thing as it shares the resources with the frame it
        was created of, but it's not a rootlevel frame any longer.

        This is only used to implement if-statements.
        """
        rv = self.copy()
        rv.rootlevel = False
        return rv

    __copy__ = copy


class VisitorExit(RuntimeError):
    """Exception used by the `UndeclaredNameVisitor` to signal a stop."""


class DependencyFinderVisitor(NodeVisitor):
    """A visitor that collects filter and test calls."""

    def __init__(self):
        self.filters = set()
        self.tests = set()

    def visit_Filter(self, node):
        self.generic_visit(node)
        self.filters.add(node.name)

    def visit_Test(self, node):
        self.generic_visit(node)
        self.tests.add(node.name)

    def visit_Block(self, node):
        """Stop visiting at blocks."""


class UndeclaredNameVisitor(NodeVisitor):
    """A visitor that checks if a name is accessed without being
    declared.  This is different from the frame visitor as it will
    not stop at closure frames.
    """

    def __init__(self, names):
        self.names = set(names)
        self.undeclared = set()

    def visit_Name(self, node):
        if node.ctx == "load" and node.name in self.names:
            self.undeclared.add(node.name)
            if self.undeclared == self.names:
                raise VisitorExit()
        else:
            self.names.discard(node.name)

    def visit_Block(self, node):
        """Stop visiting a blocks."""


class CompilerExit(Exception):
    """Raised if the compiler encountered a situation where it just
    doesn't make sense to further process the code.  Any block that
    raises such an exception is not further processed.
    """


class CodeGenerator(NodeVisitor):
    def __init__(
        self, environment, name, filename, stream=None, defer_init=False, optimized=True
    ):
        if stream is None:
            stream = StringIO()
        self.environment = environment
        self.name = name
        self.filename = filename
        self.stream = stream
        self.created_block_context = False
        self.defer_init = defer_init
        self.optimized = optimized
        if optimized:
            self.optimizer = Optimizer(environment)

        # aliases for imports
        self.import_aliases = {}

        # a registry for all blocks.  Because blocks are moved out
        # into the global python scope they are registered here
        self.blocks = {}

        # the number of extends statements so far
        self.extends_so_far = 0

        # some templates have a rootlevel extends.  In this case we
        # can safely assume that we're a child template and do some
        # more optimizations.
        self.has_known_extends = False

        # the current line number
        self.code_lineno = 1

        # registry of all filters and tests (global, not block local)
        self.tests = {}
        self.filters = {}

        # the debug information
        self.debug_info = []
        self._write_debug_info = None

        # the number of new lines before the next write()
        self._new_lines = 0

        # the line number of the last written statement
        self._last_line = 0

        # true if nothing was written so far.
        self._first_write = True

        # used by the `temporary_identifier` method to get new
        # unique, temporary identifier
        self._last_identifier = 0

        # the current indentation
        self._indentation = 0

        # Tracks toplevel assignments
        self._assign_stack = []

        # Tracks parameter definition blocks
        self._param_def_block = []

        # Tracks the current context.
        self._context_reference_stack = ["context"]

    # -- Various compilation helpers

    def fail(self, msg, lineno):
        """Fail with a :exc:`TemplateAssertionError`."""
        raise TemplateAssertionError(msg, lineno, self.name, self.filename)

    def temporary_identifier(self):
        """Get a new unique identifier."""
        self._last_identifier += 1
        return f"t_{self._last_identifier}"

    def buffer(self, frame):
        """Enable buffering for the frame from that point onwards."""
        frame.buffer = self.temporary_identifier()
        self.writeline(f"{frame.buffer} = []")

    def return_buffer_contents(self, frame, force_unescaped=False):
        """Return the buffer contents of the frame."""
        if not force_unescaped:
            if frame.eval_ctx.volatile:
                self.writeline("if context.eval_ctx.autoescape:")
                self.indent()
                self.writeline(f"return Markup(concat({frame.buffer}))")
                self.outdent()
                self.writeline("else:")
                self.indent()
                self.writeline(f"return concat({frame.buffer})")
                self.outdent()
                return
            elif frame.eval_ctx.autoescape:
                self.writeline(f"return Markup(concat({frame.buffer}))")
                return
        self.writeline(f"return concat({frame.buffer})")

    def indent(self):
        """Indent by one."""
        self._indentation += 1

    def outdent(self, step=1):
        """Outdent by step."""
        self._indentation -= step

    def start_write(self, frame, node=None):
        """Yield or write into the frame buffer."""
        if frame.buffer is None:
            self.writeline("yield ", node)
        else:
            self.writeline(f"{frame.buffer}.append(", node)

    def end_write(self, frame):
        """End the writing process started by `start_write`."""
        if frame.buffer is not None:
            self.write(")")

    def simple_write(self, s, frame, node=None):
        """Simple shortcut for start_write + write + end_write."""
        self.start_write(frame, node)
        self.write(s)
        self.end_write(frame)

    def blockvisit(self, nodes, frame):
        """Visit a list of nodes as block in a frame.  If the current frame
        is no buffer a dummy ``if 0: yield None`` is written automatically.
        """
        try:
            self.writeline("pass")
            for node in nodes:
                self.visit(node, frame)
        except CompilerExit:
            pass

    def write(self, x):
        """Write a string into the output stream."""
        if self._new_lines:
            if not self._first_write:
                self.stream.write("\n" * self._new_lines)
                self.code_lineno += self._new_lines
                if self._write_debug_info is not None:
                    self.debug_info.append((self._write_debug_info, self.code_lineno))
                    self._write_debug_info = None
            self._first_write = False
            self.stream.write("    " * self._indentation)
            self._new_lines = 0
        self.stream.write(x)

    def writeline(self, x, node=None, extra=0):
        """Combination of newline and write."""
        self.newline(node, extra)
        self.write(x)

    def newline(self, node=None, extra=0):
        """Add one or more newlines before the next write."""
        self._new_lines = max(self._new_lines, 1 + extra)
        if node is not None and node.lineno != self._last_line:
            self._write_debug_info = node.lineno
            self._last_line = node.lineno

    def signature(self, node, frame, extra_kwargs=None):
        """Writes a function call to the stream for the current node.
        A leading comma is added automatically.  The extra keyword
        arguments may not include python keywords otherwise a syntax
        error could occur.  The extra keyword arguments should be given
        as python dict.
        """
        # if any of the given keyword arguments is a python keyword
        # we have to make sure that no invalid call is created.
        kwarg_workaround = False
        for kwarg in chain((x.key for x in node.kwargs), extra_kwargs or ()):
            if is_python_keyword(kwarg):
                kwarg_workaround = True
                break

        for arg in node.args:
            self.write(", ")
            self.visit(arg, frame)

        if not kwarg_workaround:
            for kwarg in node.kwargs:
                self.write(", ")
                self.visit(kwarg, frame)
            if extra_kwargs is not None:
                for key, value in extra_kwargs.items():
                    self.write(f", {key}={value}")
        if node.dyn_args:
            self.write(", *")
            self.visit(node.dyn_args, frame)

        if kwarg_workaround:
            if node.dyn_kwargs is not None:
                self.write(", **dict({")
            else:
                self.write(", **{")
            for kwarg in node.kwargs:
                self.write(f"{kwarg.key!r}: ")
                self.visit(kwarg.value, frame)
                self.write(", ")
            if extra_kwargs is not None:
                for key, value in extra_kwargs.items():
                    self.write(f"{key!r}: {value}, ")
            if node.dyn_kwargs is not None:
                self.write("}, **")
                self.visit(node.dyn_kwargs, frame)
                self.write(")")
            else:
                self.write("}")

        elif node.dyn_kwargs is not None:
            self.write(", **")
            self.visit(node.dyn_kwargs, frame)

    def pull_dependencies(self, nodes):
        """Pull all the dependencies."""
        visitor = DependencyFinderVisitor()
        for node in nodes:
            visitor.visit(node)
        for dependency in "filters", "tests":
            mapping = getattr(self, dependency)
            for name in getattr(visitor, dependency):
                if name not in mapping:
                    mapping[name] = self.temporary_identifier()
                self.writeline(f"{mapping[name]} = environment.{dependency}[{name!r}]")

    def enter_frame(self, frame):
        undefs = []
        for target, (action, param) in frame.symbols.loads.items():
            if action == VAR_LOAD_PARAMETER:
                pass
            elif action == VAR_LOAD_RESOLVE:
                self.writeline(f"{target} = {self.get_resolve_func()}({param!r})")
            elif action == VAR_LOAD_ALIAS:
                self.writeline(f"{target} = {param}")
            elif action == VAR_LOAD_UNDEFINED:
                undefs.append(target)
            else:
                raise NotImplementedError("unknown load instruction")
        if undefs:
            self.writeline(f"{' = '.join(undefs)} = missing")

    def leave_frame(self, frame, with_python_scope=False):
        if not with_python_scope:
            undefs = []
            for target in frame.symbols.loads:
                undefs.append(target)
            if undefs:
                self.writeline(f"{' = '.join(undefs)} = missing")

    def func(self, name):
        if self.environment.is_async:
            return f"async def {name}"
        return f"def {name}"

    def macro_body(self, node, frame):
        """Dump the function def of a macro or call block."""
        frame = frame.inner()
        frame.symbols.analyze_node(node)
        macro_ref = MacroRef(node)

        explicit_caller = None
        skip_special_params = set()
        args = []
        for idx, arg in enumerate(node.args):
            if arg.name == "caller":
                explicit_caller = idx
            if arg.name in ("kwargs", "varargs"):
                skip_special_params.add(arg.name)
            args.append(frame.symbols.ref(arg.name))

        undeclared = find_undeclared(node.body, ("caller", "kwargs", "varargs"))

        if "caller" in undeclared:
            # In older Jinja versions there was a bug that allowed caller
            # to retain the special behavior even if it was mentioned in
            # the argument list.  However thankfully this was only really
            # working if it was the last argument.  So we are explicitly
            # checking this now and error out if it is anywhere else in
            # the argument list.
            if explicit_caller is not None:
                try:
                    node.defaults[explicit_caller - len(node.args)]
                except IndexError:
                    self.fail(
                        "When defining macros or call blocks the "
                        'special "caller" argument must be omitted '
                        "or be given a default.",
                        node.lineno,
                    )
            else:
                args.append(frame.symbols.declare_parameter("caller"))
            macro_ref.accesses_caller = True
        if "kwargs" in undeclared and "kwargs" not in skip_special_params:
            args.append(frame.symbols.declare_parameter("kwargs"))
            macro_ref.accesses_kwargs = True
        if "varargs" in undeclared and "varargs" not in skip_special_params:
            args.append(frame.symbols.declare_parameter("varargs"))
            macro_ref.accesses_varargs = True

        # macros are delayed, they never require output checks
        frame.require_output_check = False
        frame.symbols.analyze_node(node)
        self.writeline(f"{self.func('macro')}({', '.join(args)}):", node)
        self.indent()

        self.buffer(frame)
        self.enter_frame(frame)

        self.push_parameter_definitions(frame)
        for idx, arg in enumerate(node.args):
            ref = frame.symbols.ref(arg.name)
            self.writeline(f"if {ref} is missing:")
            self.indent()
            try:
                default = node.defaults[idx - len(node.args)]
            except IndexError:
                self.writeline(
                    f'{ref} = undefined("parameter {arg.name!r} was not provided",'
                    f" name={arg.name!r})"
                )
            else:
                self.writeline(f"{ref} = ")
                self.visit(default, frame)
            self.mark_parameter_stored(ref)
            self.outdent()
        self.pop_parameter_definitions()

        self.blockvisit(node.body, frame)
        self.return_buffer_contents(frame, force_unescaped=True)
        self.leave_frame(frame, with_python_scope=True)
        self.outdent()

        return frame, macro_ref

    def macro_def(self, macro_ref, frame):
        """Dump the macro definition for the def created by macro_body."""
        arg_tuple = ", ".join(repr(x.name) for x in macro_ref.node.args)
        name = getattr(macro_ref.node, "name", None)
        if len(macro_ref.node.args) == 1:
            arg_tuple += ","
        self.write(
            f"Macro(environment, macro, {name!r}, ({arg_tuple}),"
            f" {macro_ref.accesses_kwargs!r}, {macro_ref.accesses_varargs!r},"
            f" {macro_ref.accesses_caller!r}, context.eval_ctx.autoescape)"
        )

    def position(self, node):
        """Return a human readable position for the node."""
        rv = f"line {node.lineno}"
        if self.name is not None:
            rv = f"{rv} in {self.name!r}"
        return rv

    def dump_local_context(self, frame):
        items_kv = ", ".join(
            f"{name!r}: {target}"
            for name, target in frame.symbols.dump_stores().items()
        )
        return f"{{{items_kv}}}"

    def write_commons(self):
        """Writes a common preamble that is used by root and block functions.
        Primarily this sets up common local helpers and enforces a generator
        through a dead branch.
        """
        self.writeline("resolve = context.resolve_or_missing")
        self.writeline("undefined = environment.undefined")
        # always use the standard Undefined class for the implicit else of
        # conditional expressions
        self.writeline("cond_expr_undefined = Undefined")
        self.writeline("if 0: yield None")

    def push_parameter_definitions(self, frame):
        """Pushes all parameter targets from the given frame into a local
        stack that permits tracking of yet to be assigned parameters.  In
        particular this enables the optimization from `visit_Name` to skip
        undefined expressions for parameters in macros as macros can reference
        otherwise unbound parameters.
        """
        self._param_def_block.append(frame.symbols.dump_param_targets())

    def pop_parameter_definitions(self):
        """Pops the current parameter definitions set."""
        self._param_def_block.pop()

    def mark_parameter_stored(self, target):
        """Marks a parameter in the current parameter definitions as stored.
        This will skip the enforced undefined checks.
        """
        if self._param_def_block:
            self._param_def_block[-1].discard(target)

    def push_context_reference(self, target):
        self._context_reference_stack.append(target)

    def pop_context_reference(self):
        self._context_reference_stack.pop()

    def get_context_ref(self):
        return self._context_reference_stack[-1]

    def get_resolve_func(self):
        target = self._context_reference_stack[-1]
        if target == "context":
            return "resolve"
        return f"{target}.resolve"

    def derive_context(self, frame):
        return f"{self.get_context_ref()}.derived({self.dump_local_context(frame)})"

    def parameter_is_undeclared(self, target):
        """Checks if a given target is an undeclared parameter."""
        if not self._param_def_block:
            return False
        return target in self._param_def_block[-1]

    def push_assign_tracking(self):
        """Pushes a new layer for assignment tracking."""
        self._assign_stack.append(set())

    def pop_assign_tracking(self, frame):
        """Pops the topmost level for assignment tracking and updates the
        context variables if necessary.
        """
        vars = self._assign_stack.pop()
        if not frame.toplevel or not vars:
            return
        public_names = [x for x in vars if x[:1] != "_"]
        if len(vars) == 1:
            name = next(iter(vars))
            ref = frame.symbols.ref(name)
            self.writeline(f"context.vars[{name!r}] = {ref}")
        else:
            self.writeline("context.vars.update({")
            for idx, name in enumerate(vars):
                if idx:
                    self.write(", ")
                ref = frame.symbols.ref(name)
                self.write(f"{name!r}: {ref}")
            self.write("})")
        if public_names:
            if len(public_names) == 1:
                self.writeline(f"context.exported_vars.add({public_names[0]!r})")
            else:
                names_str = ", ".join(map(repr, public_names))
                self.writeline(f"context.exported_vars.update(({names_str}))")

    # -- Statement Visitors

    def visit_Template(self, node, frame=None):
        assert frame is None, "no root frame allowed"
        eval_ctx = EvalContext(self.environment, self.name)

        from .runtime import exported

        self.writeline("from __future__ import generator_stop")  # Python < 3.7
        self.writeline("from jinja2.runtime import " + ", ".join(exported))

        if self.environment.is_async:
            self.writeline(
                "from jinja2.asyncsupport import auto_await, "
                "auto_aiter, AsyncLoopContext"
            )

        # if we want a deferred initialization we cannot move the
        # environment into a local name
        envenv = "" if self.defer_init else ", environment=environment"

        # do we have an extends tag at all?  If not, we can save some
        # overhead by just not processing any inheritance code.
        have_extends = node.find(nodes.Extends) is not None

        # find all blocks
        for block in node.find_all(nodes.Block):
            if block.name in self.blocks:
                self.fail(f"block {block.name!r} defined twice", block.lineno)
            self.blocks[block.name] = block

        # find all imports and import them
        for import_ in node.find_all(nodes.ImportedName):
            if import_.importname not in self.import_aliases:
                imp = import_.importname
                self.import_aliases[imp] = alias = self.temporary_identifier()
                if "." in imp:
                    module, obj = imp.rsplit(".", 1)
                    self.writeline(f"from {module} import {obj} as {alias}")
                else:
                    self.writeline(f"import {imp} as {alias}")

        # add the load name
        self.writeline(f"name = {self.name!r}")

        # generate the root render function.
        self.writeline(
            f"{self.func('root')}(context, missing=missing{envenv}):", extra=1
        )
        self.indent()
        self.write_commons()

        # process the root
        frame = Frame(eval_ctx)
        if "self" in find_undeclared(node.body, ("self",)):
            ref = frame.symbols.declare_parameter("self")
            self.writeline(f"{ref} = TemplateReference(context)")
        frame.symbols.analyze_node(node)
        frame.toplevel = frame.rootlevel = True
        frame.require_output_check = have_extends and not self.has_known_extends
        if have_extends:
            self.writeline("parent_template = None")
        self.enter_frame(frame)
        self.pull_dependencies(node.body)
        self.blockvisit(node.body, frame)
        self.leave_frame(frame, with_python_scope=True)
        self.outdent()

        # make sure that the parent root is called.
        if have_extends:
            if not self.has_known_extends:
                self.indent()
                self.writeline("if parent_template is not None:")
            self.indent()
            if not self.environment.is_async:
                self.writeline("yield from parent_template.root_render_func(context)")
            else:
                loop = "async for" if self.environment.is_async else "for"
                self.writeline(
                    f"{loop} event in parent_template.root_render_func(context):"
                )
                self.indent()
                self.writeline("yield event")
                self.outdent()
            self.outdent(1 + (not self.has_known_extends))

        # at this point we now have the blocks collected and can visit them too.
        for name, block in self.blocks.items():
            self.writeline(
                f"{self.func('block_' + name)}(context, missing=missing{envenv}):",
                block,
                1,
            )
            self.indent()
            self.write_commons()
            # It's important that we do not make this frame a child of the
            # toplevel template.  This would cause a variety of
            # interesting issues with identifier tracking.
            block_frame = Frame(eval_ctx)
            undeclared = find_undeclared(block.body, ("self", "super"))
            if "self" in undeclared:
                ref = block_frame.symbols.declare_parameter("self")
                self.writeline(f"{ref} = TemplateReference(context)")
            if "super" in undeclared:
                ref = block_frame.symbols.declare_parameter("super")
                self.writeline(f"{ref} = context.super({name!r}, block_{name})")
            block_frame.symbols.analyze_node(block)
            block_frame.block = name
            self.enter_frame(block_frame)
            self.pull_dependencies(block.body)
            self.blockvisit(block.body, block_frame)
            self.leave_frame(block_frame, with_python_scope=True)
            self.outdent()

        blocks_kv_str = ", ".join(f"{x!r}: block_{x}" for x in self.blocks)
        self.writeline(f"blocks = {{{blocks_kv_str}}}", extra=1)
        debug_kv_str = "&".join(f"{k}={v}" for k, v in self.debug_info)
        self.writeline(f"debug_info = {debug_kv_str!r}")

    def visit_Block(self, node, frame):
        """Call a block and register it for the template."""
        level = 0
        if frame.toplevel:
            # if we know that we are a child template, there is no need to
            # check if we are one
            if self.has_known_extends:
                return
            if self.extends_so_far > 0:
                self.writeline("if parent_template is None:")
                self.indent()
                level += 1

        if node.scoped:
            context = self.derive_context(frame)
        else:
            context = self.get_context_ref()

        if not self.environment.is_async and frame.buffer is None:
            self.writeline(
                f"yield from context.blocks[{node.name!r}][0]({context})", node
            )
        else:
            loop = "async for" if self.environment.is_async else "for"
            self.writeline(
                f"{loop} event in context.blocks[{node.name!r}][0]({context}):", node
            )
            self.indent()
            self.simple_write("event", frame)
            self.outdent()

        self.outdent(level)

    def visit_Extends(self, node, frame):
        """Calls the extender."""
        if not frame.toplevel:
            self.fail("cannot use extend from a non top-level scope", node.lineno)

        # if the number of extends statements in general is zero so
        # far, we don't have to add a check if something extended
        # the template before this one.
        if self.extends_so_far > 0:

            # if we have a known extends we just add a template runtime
            # error into the generated code.  We could catch that at compile
            # time too, but i welcome it not to confuse users by throwing the
            # same error at different times just "because we can".
            if not self.has_known_extends:
                self.writeline("if parent_template is not None:")
                self.indent()
            self.writeline('raise TemplateRuntimeError("extended multiple times")')

            # if we have a known extends already we don't need that code here
            # as we know that the template execution will end here.
            if self.has_known_extends:
                raise CompilerExit()
            else:
                self.outdent()

        self.writeline("parent_template = environment.get_template(", node)
        self.visit(node.template, frame)
        self.write(f", {self.name!r})")
        self.writeline("for name, parent_block in parent_template.blocks.items():")
        self.indent()
        self.writeline("context.blocks.setdefault(name, []).append(parent_block)")
        self.outdent()

        # if this extends statement was in the root level we can take
        # advantage of that information and simplify the generated code
        # in the top level from this point onwards
        if frame.rootlevel:
            self.has_known_extends = True

        # and now we have one more
        self.extends_so_far += 1

    def visit_Include(self, node, frame):
        """Handles includes."""
        if node.ignore_missing:
            self.writeline("try:")
            self.indent()

        func_name = "get_or_select_template"
        if isinstance(node.template, nodes.Const):
            if isinstance(node.template.value, str):
                func_name = "get_template"
            elif isinstance(node.template.value, (tuple, list)):
                func_name = "select_template"
        elif isinstance(node.template, (nodes.Tuple, nodes.List)):
            func_name = "select_template"

        self.writeline(f"template = environment.{func_name}(", node)
        self.visit(node.template, frame)
        self.write(f", {self.name!r})")
        if node.ignore_missing:
            self.outdent()
            self.writeline("except TemplateNotFound:")
            self.indent()
            self.writeline("pass")
            self.outdent()
            self.writeline("else:")
            self.indent()

        skip_event_yield = False
        if node.with_context:
            loop = "async for" if self.environment.is_async else "for"
            self.writeline(
                f"{loop} event in template.root_render_func("
                "template.new_context(context.get_all(), True,"
                f" {self.dump_local_context(frame)})):"
            )
        elif self.environment.is_async:
            self.writeline(
                "for event in (await template._get_default_module_async())"
                "._body_stream:"
            )
        else:
            self.writeline("yield from template._get_default_module()._body_stream")
            skip_event_yield = True

        if not skip_event_yield:
            self.indent()
            self.simple_write("event", frame)
            self.outdent()

        if node.ignore_missing:
            self.outdent()

    def visit_Import(self, node, frame):
        """Visit regular imports."""
        self.writeline(f"{frame.symbols.ref(node.target)} = ", node)
        if frame.toplevel:
            self.write(f"context.vars[{node.target!r}] = ")
        if self.environment.is_async:
            self.write("await ")
        self.write("environment.get_template(")
        self.visit(node.template, frame)
        self.write(f", {self.name!r}).")
        if node.with_context:
            func = "make_module" + ("_async" if self.environment.is_async else "")
            self.write(
                f"{func}(context.get_all(), True, {self.dump_local_context(frame)})"
            )
        elif self.environment.is_async:
            self.write("_get_default_module_async()")
        else:
            self.write("_get_default_module(context)")
        if frame.toplevel and not node.target.startswith("_"):
            self.writeline(f"context.exported_vars.discard({node.target!r})")

    def visit_FromImport(self, node, frame):
        """Visit named imports."""
        self.newline(node)
        prefix = "await " if self.environment.is_async else ""
        self.write(f"included_template = {prefix}environment.get_template(")
        self.visit(node.template, frame)
        self.write(f", {self.name!r}).")
        if node.with_context:
            func = "make_module" + ("_async" if self.environment.is_async else "")
            self.write(
                f"{func}(context.get_all(), True, {self.dump_local_context(frame)})"
            )
        elif self.environment.is_async:
            self.write("_get_default_module_async()")
        else:
            self.write("_get_default_module(context)")

        var_names = []
        discarded_names = []
        for name in node.names:
            if isinstance(name, tuple):
                name, alias = name
            else:
                alias = name
            self.writeline(
                f"{frame.symbols.ref(alias)} ="
                f" getattr(included_template, {name!r}, missing)"
            )
            self.writeline(f"if {frame.symbols.ref(alias)} is missing:")
            self.indent()
            message = (
                "the template {included_template.__name__!r}"
                f" (imported on {self.position(node)})"
                f" does not export the requested name {name!r}"
            )
            self.writeline(
                f"{frame.symbols.ref(alias)} = undefined(f{message!r}, name={name!r})"
            )
            self.outdent()
            if frame.toplevel:
                var_names.append(alias)
                if not alias.startswith("_"):
                    discarded_names.append(alias)

        if var_names:
            if len(var_names) == 1:
                name = var_names[0]
                self.writeline(f"context.vars[{name!r}] = {frame.symbols.ref(name)}")
            else:
                names_kv = ", ".join(
                    f"{name!r}: {frame.symbols.ref(name)}" for name in var_names
                )
                self.writeline(f"context.vars.update({{{names_kv}}})")
        if discarded_names:
            if len(discarded_names) == 1:
                self.writeline(f"context.exported_vars.discard({discarded_names[0]!r})")
            else:
                names_str = ", ".join(map(repr, discarded_names))
                self.writeline(
                    f"context.exported_vars.difference_update(({names_str}))"
                )

    def visit_For(self, node, frame):
        loop_frame = frame.inner()
        test_frame = frame.inner()
        else_frame = frame.inner()

        # try to figure out if we have an extended loop.  An extended loop
        # is necessary if the loop is in recursive mode if the special loop
        # variable is accessed in the body.
        extended_loop = node.recursive or "loop" in find_undeclared(
            node.iter_child_nodes(only=("body",)), ("loop",)
        )

        loop_ref = None
        if extended_loop:
            loop_ref = loop_frame.symbols.declare_parameter("loop")

        loop_frame.symbols.analyze_node(node, for_branch="body")
        if node.else_:
            else_frame.symbols.analyze_node(node, for_branch="else")

        if node.test:
            loop_filter_func = self.temporary_identifier()
            test_frame.symbols.analyze_node(node, for_branch="test")
            self.writeline(f"{self.func(loop_filter_func)}(fiter):", node.test)
            self.indent()
            self.enter_frame(test_frame)
            self.writeline("async for " if self.environment.is_async else "for ")
            self.visit(node.target, loop_frame)
            self.write(" in ")
            self.write("auto_aiter(fiter)" if self.environment.is_async else "fiter")
            self.write(":")
            self.indent()
            self.writeline("if ", node.test)
            self.visit(node.test, test_frame)
            self.write(":")
            self.indent()
            self.writeline("yield ")
            self.visit(node.target, loop_frame)
            self.outdent(3)
            self.leave_frame(test_frame, with_python_scope=True)

        # if we don't have an recursive loop we have to find the shadowed
        # variables at that point.  Because loops can be nested but the loop
        # variable is a special one we have to enforce aliasing for it.
        if node.recursive:
            self.writeline(
                f"{self.func('loop')}(reciter, loop_render_func, depth=0):", node
            )
            self.indent()
            self.buffer(loop_frame)

            # Use the same buffer for the else frame
            else_frame.buffer = loop_frame.buffer

        # make sure the loop variable is a special one and raise a template
        # assertion error if a loop tries to write to loop
        if extended_loop:
            self.writeline(f"{loop_ref} = missing")

        for name in node.find_all(nodes.Name):
            if name.ctx == "store" and name.name == "loop":
                self.fail(
                    "Can't assign to special loop variable in for-loop target",
                    name.lineno,
                )

        if node.else_:
            iteration_indicator = self.temporary_identifier()
            self.writeline(f"{iteration_indicator} = 1")

        self.writeline("async for " if self.environment.is_async else "for ", node)
        self.visit(node.target, loop_frame)
        if extended_loop:
            prefix = "Async" if self.environment.is_async else ""
            self.write(f", {loop_ref} in {prefix}LoopContext(")
        else:
            self.write(" in ")

        if node.test:
            self.write(f"{loop_filter_func}(")
        if node.recursive:
            self.write("reciter")
        else:
            if self.environment.is_async and not extended_loop:
                self.write("auto_aiter(")
            self.visit(node.iter, frame)
            if self.environment.is_async and not extended_loop:
                self.write(")")
        if node.test:
            self.write(")")

        if node.recursive:
            self.write(", undefined, loop_render_func, depth):")
        else:
            self.write(", undefined):" if extended_loop else ":")

        self.indent()
        self.enter_frame(loop_frame)

        self.blockvisit(node.body, loop_frame)
        if node.else_:
            self.writeline(f"{iteration_indicator} = 0")
        self.outdent()
        self.leave_frame(
            loop_frame, with_python_scope=node.recursive and not node.else_
        )

        if node.else_:
            self.writeline(f"if {iteration_indicator}:")
            self.indent()
            self.enter_frame(else_frame)
            self.blockvisit(node.else_, else_frame)
            self.leave_frame(else_frame)
            self.outdent()

        # if the node was recursive we have to return the buffer contents
        # and start the iteration code
        if node.recursive:
            self.return_buffer_contents(loop_frame)
            self.outdent()
            self.start_write(frame, node)
            if self.environment.is_async:
                self.write("await ")
            self.write("loop(")
            if self.environment.is_async:
                self.write("auto_aiter(")
            self.visit(node.iter, frame)
            if self.environment.is_async:
                self.write(")")
            self.write(", loop)")
            self.end_write(frame)

    def visit_If(self, node, frame):
        if_frame = frame.soft()
        self.writeline("if ", node)
        self.visit(node.test, if_frame)
        self.write(":")
        self.indent()
        self.blockvisit(node.body, if_frame)
        self.outdent()
        for elif_ in node.elif_:
            self.writeline("elif ", elif_)
            self.visit(elif_.test, if_frame)
            self.write(":")
            self.indent()
            self.blockvisit(elif_.body, if_frame)
            self.outdent()
        if node.else_:
            self.writeline("else:")
            self.indent()
            self.blockvisit(node.else_, if_frame)
            self.outdent()

    def visit_Macro(self, node, frame):
        macro_frame, macro_ref = self.macro_body(node, frame)
        self.newline()
        if frame.toplevel:
            if not node.name.startswith("_"):
                self.write(f"context.exported_vars.add({node.name!r})")
            self.writeline(f"context.vars[{node.name!r}] = ")
        self.write(f"{frame.symbols.ref(node.name)} = ")
        self.macro_def(macro_ref, macro_frame)

    def visit_CallBlock(self, node, frame):
        call_frame, macro_ref = self.macro_body(node, frame)
        self.writeline("caller = ")
        self.macro_def(macro_ref, call_frame)
        self.start_write(frame, node)
        self.visit_Call(node.call, frame, forward_caller=True)
        self.end_write(frame)

    def visit_FilterBlock(self, node, frame):
        filter_frame = frame.inner()
        filter_frame.symbols.analyze_node(node)
        self.enter_frame(filter_frame)
        self.buffer(filter_frame)
        self.blockvisit(node.body, filter_frame)
        self.start_write(frame, node)
        self.visit_Filter(node.filter, filter_frame)
        self.end_write(frame)
        self.leave_frame(filter_frame)

    def visit_With(self, node, frame):
        with_frame = frame.inner()
        with_frame.symbols.analyze_node(node)
        self.enter_frame(with_frame)
        for target, expr in zip(node.targets, node.values):
            self.newline()
            self.visit(target, with_frame)
            self.write(" = ")
            self.visit(expr, frame)
        self.blockvisit(node.body, with_frame)
        self.leave_frame(with_frame)

    def visit_ExprStmt(self, node, frame):
        self.newline(node)
        self.visit(node.node, frame)

    _FinalizeInfo = namedtuple("_FinalizeInfo", ("const", "src"))
    #: The default finalize function if the environment isn't configured
    #: with one. Or if the environment has one, this is called on that
    #: function's output for constants.
    _default_finalize = str
    _finalize = None

    def _make_finalize(self):
        """Build the finalize function to be used on constants and at
        runtime. Cached so it's only created once for all output nodes.

        Returns a ``namedtuple`` with the following attributes:

        ``const``
            A function to finalize constant data at compile time.

        ``src``
            Source code to output around nodes to be evaluated at
            runtime.
        """
        if self._finalize is not None:
            return self._finalize

        finalize = default = self._default_finalize
        src = None

        if self.environment.finalize:
            src = "environment.finalize("
            env_finalize = self.environment.finalize

            def finalize(value):
                return default(env_finalize(value))

            if getattr(env_finalize, "contextfunction", False) is True:
                src += "context, "
                finalize = None  # noqa: F811
            elif getattr(env_finalize, "evalcontextfunction", False) is True:
                src += "context.eval_ctx, "
                finalize = None
            elif getattr(env_finalize, "environmentfunction", False) is True:
                src += "environment, "

                def finalize(value):
                    return default(env_finalize(self.environment, value))

        self._finalize = self._FinalizeInfo(finalize, src)
        return self._finalize

    def _output_const_repr(self, group):
        """Given a group of constant values converted from ``Output``
        child nodes, produce a string to write to the template module
        source.
        """
        return repr(concat(group))

    def _output_child_to_const(self, node, frame, finalize):
        """Try to optimize a child of an ``Output`` node by trying to
        convert it to constant, finalized data at compile time.

        If :exc:`Impossible` is raised, the node is not constant and
        will be evaluated at runtime. Any other exception will also be
        evaluated at runtime for easier debugging.
        """
        const = node.as_const(frame.eval_ctx)

        if frame.eval_ctx.autoescape:
            const = escape(const)

        # Template data doesn't go through finalize.
        if isinstance(node, nodes.TemplateData):
            return str(const)

        return finalize.const(const)

    def _output_child_pre(self, node, frame, finalize):
        """Output extra source code before visiting a child of an
        ``Output`` node.
        """
        if frame.eval_ctx.volatile:
            self.write("(escape if context.eval_ctx.autoescape else str)(")
        elif frame.eval_ctx.autoescape:
            self.write("escape(")
        else:
            self.write("str(")

        if finalize.src is not None:
            self.write(finalize.src)

    def _output_child_post(self, node, frame, finalize):
        """Output extra source code after visiting a child of an
        ``Output`` node.
        """
        self.write(")")

        if finalize.src is not None:
            self.write(")")

    def visit_Output(self, node, frame):
        # If an extends is active, don't render outside a block.
        if frame.require_output_check:
            # A top-level extends is known to exist at compile time.
            if self.has_known_extends:
                return

            self.writeline("if parent_template is None:")
            self.indent()

        finalize = self._make_finalize()
        body = []

        # Evaluate constants at compile time if possible. Each item in
        # body will be either a list of static data or a node to be
        # evaluated at runtime.
        for child in node.nodes:
            try:
                if not (
                    # If the finalize function requires runtime context,
                    # constants can't be evaluated at compile time.
                    finalize.const
                    # Unless it's basic template data that won't be
                    # finalized anyway.
                    or isinstance(child, nodes.TemplateData)
                ):
                    raise nodes.Impossible()

                const = self._output_child_to_const(child, frame, finalize)
            except (nodes.Impossible, Exception):
                # The node was not constant and needs to be evaluated at
                # runtime. Or another error was raised, which is easier
                # to debug at runtime.
                body.append(child)
                continue

            if body and isinstance(body[-1], list):
                body[-1].append(const)
            else:
                body.append([const])

        if frame.buffer is not None:
            if len(body) == 1:
                self.writeline(f"{frame.buffer}.append(")
            else:
                self.writeline(f"{frame.buffer}.extend((")

            self.indent()

        for item in body:
            if isinstance(item, list):
                # A group of constant data to join and output.
                val = self._output_const_repr(item)

                if frame.buffer is None:
                    self.writeline("yield " + val)
                else:
                    self.writeline(val + ",")
            else:
                if frame.buffer is None:
                    self.writeline("yield ", item)
                else:
                    self.newline(item)

                # A node to be evaluated at runtime.
                self._output_child_pre(item, frame, finalize)
                self.visit(item, frame)
                self._output_child_post(item, frame, finalize)

                if frame.buffer is not None:
                    self.write(",")

        if frame.buffer is not None:
            self.outdent()
            self.writeline(")" if len(body) == 1 else "))")

        if frame.require_output_check:
            self.outdent()

    def visit_Assign(self, node, frame):
        self.push_assign_tracking()
        self.newline(node)
        self.visit(node.target, frame)
        self.write(" = ")
        self.visit(node.node, frame)
        self.pop_assign_tracking(frame)

    def visit_AssignBlock(self, node, frame):
        self.push_assign_tracking()
        block_frame = frame.inner()
        # This is a special case.  Since a set block always captures we
        # will disable output checks.  This way one can use set blocks
        # toplevel even in extended templates.
        block_frame.require_output_check = False
        block_frame.symbols.analyze_node(node)
        self.enter_frame(block_frame)
        self.buffer(block_frame)
        self.blockvisit(node.body, block_frame)
        self.newline(node)
        self.visit(node.target, frame)
        self.write(" = (Markup if context.eval_ctx.autoescape else identity)(")
        if node.filter is not None:
            self.visit_Filter(node.filter, block_frame)
        else:
            self.write(f"concat({block_frame.buffer})")
        self.write(")")
        self.pop_assign_tracking(frame)
        self.leave_frame(block_frame)

    # -- Expression Visitors

    def visit_Name(self, node, frame):
        if node.ctx == "store" and frame.toplevel:
            if self._assign_stack:
                self._assign_stack[-1].add(node.name)
        ref = frame.symbols.ref(node.name)

        # If we are looking up a variable we might have to deal with the
        # case where it's undefined.  We can skip that case if the load
        # instruction indicates a parameter which are always defined.
        if node.ctx == "load":
            load = frame.symbols.find_load(ref)
            if not (
                load is not None
                and load[0] == VAR_LOAD_PARAMETER
                and not self.parameter_is_undeclared(ref)
            ):
                self.write(
                    f"(undefined(name={node.name!r}) if {ref} is missing else {ref})"
                )
                return

        self.write(ref)

    def visit_NSRef(self, node, frame):
        # NSRefs can only be used to store values; since they use the normal
        # `foo.bar` notation they will be parsed as a normal attribute access
        # when used anywhere but in a `set` context
        ref = frame.symbols.ref(node.name)
        self.writeline(f"if not isinstance({ref}, Namespace):")
        self.indent()
        self.writeline(
            "raise TemplateRuntimeError"
            '("cannot assign attribute on non-namespace object")'
        )
        self.outdent()
        self.writeline(f"{ref}[{node.attr!r}]")

    def visit_Const(self, node, frame):
        val = node.as_const(frame.eval_ctx)
        if isinstance(val, float):
            self.write(str(val))
        else:
            self.write(repr(val))

    def visit_TemplateData(self, node, frame):
        try:
            self.write(repr(node.as_const(frame.eval_ctx)))
        except nodes.Impossible:
            self.write(
                f"(Markup if context.eval_ctx.autoescape else identity)({node.data!r})"
            )

    def visit_Tuple(self, node, frame):
        self.write("(")
        idx = -1
        for idx, item in enumerate(node.items):
            if idx:
                self.write(", ")
            self.visit(item, frame)
        self.write(",)" if idx == 0 else ")")

    def visit_List(self, node, frame):
        self.write("[")
        for idx, item in enumerate(node.items):
            if idx:
                self.write(", ")
            self.visit(item, frame)
        self.write("]")

    def visit_Dict(self, node, frame):
        self.write("{")
        for idx, item in enumerate(node.items):
            if idx:
                self.write(", ")
            self.visit(item.key, frame)
            self.write(": ")
            self.visit(item.value, frame)
        self.write("}")

    def binop(operator, interceptable=True):  # noqa: B902
        @optimizeconst
        def visitor(self, node, frame):
            if (
                self.environment.sandboxed
                and operator in self.environment.intercepted_binops
            ):
                self.write(f"environment.call_binop(context, {operator!r}, ")
                self.visit(node.left, frame)
                self.write(", ")
                self.visit(node.right, frame)
            else:
                self.write("(")
                self.visit(node.left, frame)
                self.write(f" {operator} ")
                self.visit(node.right, frame)
            self.write(")")

        return visitor

    def uaop(operator, interceptable=True):  # noqa: B902
        @optimizeconst
        def visitor(self, node, frame):
            if (
                self.environment.sandboxed
                and operator in self.environment.intercepted_unops
            ):
                self.write(f"environment.call_unop(context, {operator!r}, ")
                self.visit(node.node, frame)
            else:
                self.write("(" + operator)
                self.visit(node.node, frame)
            self.write(")")

        return visitor

    visit_Add = binop("+")
    visit_Sub = binop("-")
    visit_Mul = binop("*")
    visit_Div = binop("/")
    visit_FloorDiv = binop("//")
    visit_Pow = binop("**")
    visit_Mod = binop("%")
    visit_And = binop("and", interceptable=False)
    visit_Or = binop("or", interceptable=False)
    visit_Pos = uaop("+")
    visit_Neg = uaop("-")
    visit_Not = uaop("not ", interceptable=False)
    del binop, uaop

    @optimizeconst
    def visit_Concat(self, node, frame):
        if frame.eval_ctx.volatile:
            func_name = "(markup_join if context.eval_ctx.volatile else str_join)"
        elif frame.eval_ctx.autoescape:
            func_name = "markup_join"
        else:
            func_name = "str_join"
        self.write(f"{func_name}((")
        for arg in node.nodes:
            self.visit(arg, frame)
            self.write(", ")
        self.write("))")

    @optimizeconst
    def visit_Compare(self, node, frame):
        self.write("(")
        self.visit(node.expr, frame)
        for op in node.ops:
            self.visit(op, frame)
        self.write(")")

    def visit_Operand(self, node, frame):
        self.write(f" {operators[node.op]} ")
        self.visit(node.expr, frame)

    @optimizeconst
    def visit_Getattr(self, node, frame):
        if self.environment.is_async:
            self.write("(await auto_await(")

        self.write("environment.getattr(")
        self.visit(node.node, frame)
        self.write(f", {node.attr!r})")

        if self.environment.is_async:
            self.write("))")

    @optimizeconst
    def visit_Getitem(self, node, frame):
        # slices bypass the environment getitem method.
        if isinstance(node.arg, nodes.Slice):
            self.visit(node.node, frame)
            self.write("[")
            self.visit(node.arg, frame)
            self.write("]")
        else:
            if self.environment.is_async:
                self.write("(await auto_await(")

            self.write("environment.getitem(")
            self.visit(node.node, frame)
            self.write(", ")
            self.visit(node.arg, frame)
            self.write(")")

            if self.environment.is_async:
                self.write("))")

    def visit_Slice(self, node, frame):
        if node.start is not None:
            self.visit(node.start, frame)
        self.write(":")
        if node.stop is not None:
            self.visit(node.stop, frame)
        if node.step is not None:
            self.write(":")
            self.visit(node.step, frame)

    @optimizeconst
    def visit_Filter(self, node, frame):
        if self.environment.is_async:
            self.write("await auto_await(")
        self.write(self.filters[node.name] + "(")
        func = self.environment.filters.get(node.name)
        if func is None:
            self.fail(f"no filter named {node.name!r}", node.lineno)
        if getattr(func, "contextfilter", False) is True:
            self.write("context, ")
        elif getattr(func, "evalcontextfilter", False) is True:
            self.write("context.eval_ctx, ")
        elif getattr(func, "environmentfilter", False) is True:
            self.write("environment, ")

        # if the filter node is None we are inside a filter block
        # and want to write to the current buffer
        if node.node is not None:
            self.visit(node.node, frame)
        elif frame.eval_ctx.volatile:
            self.write(
                f"(Markup(concat({frame.buffer}))"
                f" if context.eval_ctx.autoescape else concat({frame.buffer}))"
            )
        elif frame.eval_ctx.autoescape:
            self.write(f"Markup(concat({frame.buffer}))")
        else:
            self.write(f"concat({frame.buffer})")
        self.signature(node, frame)
        self.write(")")
        if self.environment.is_async:
            self.write(")")

    @optimizeconst
    def visit_Test(self, node, frame):
        self.write(self.tests[node.name] + "(")
        if node.name not in self.environment.tests:
            self.fail(f"no test named {node.name!r}", node.lineno)
        self.visit(node.node, frame)
        self.signature(node, frame)
        self.write(")")

    @optimizeconst
    def visit_CondExpr(self, node, frame):
        def write_expr2():
            if node.expr2 is not None:
                return self.visit(node.expr2, frame)
            self.write(
                f'cond_expr_undefined("the inline if-expression on'
                f" {self.position(node)} evaluated to false and no else"
                f' section was defined.")'
            )

        self.write("(")
        self.visit(node.expr1, frame)
        self.write(" if ")
        self.visit(node.test, frame)
        self.write(" else ")
        write_expr2()
        self.write(")")

    @optimizeconst
    def visit_Call(self, node, frame, forward_caller=False):
        if self.environment.is_async:
            self.write("await auto_await(")
        if self.environment.sandboxed:
            self.write("environment.call(context, ")
        else:
            self.write("context.call(")
        self.visit(node.node, frame)
        extra_kwargs = {"caller": "caller"} if forward_caller else None
        self.signature(node, frame, extra_kwargs)
        self.write(")")
        if self.environment.is_async:
            self.write(")")

    def visit_Keyword(self, node, frame):
        self.write(node.key + "=")
        self.visit(node.value, frame)

    # -- Unused nodes for extensions

    def visit_MarkSafe(self, node, frame):
        self.write("Markup(")
        self.visit(node.expr, frame)
        self.write(")")

    def visit_MarkSafeIfAutoescape(self, node, frame):
        self.write("(Markup if context.eval_ctx.autoescape else identity)(")
        self.visit(node.expr, frame)
        self.write(")")

    def visit_EnvironmentAttribute(self, node, frame):
        self.write("environment." + node.name)

    def visit_ExtensionAttribute(self, node, frame):
        self.write(f"environment.extensions[{node.identifier!r}].{node.name}")

    def visit_ImportedName(self, node, frame):
        self.write(self.import_aliases[node.importname])

    def visit_InternalName(self, node, frame):
        self.write(node.name)

    def visit_ContextReference(self, node, frame):
        self.write("context")

    def visit_DerivedContextReference(self, node, frame):
        self.write(self.derive_context(frame))

    def visit_Continue(self, node, frame):
        self.writeline("continue", node)

    def visit_Break(self, node, frame):
        self.writeline("break", node)

    def visit_Scope(self, node, frame):
        scope_frame = frame.inner()
        scope_frame.symbols.analyze_node(node)
        self.enter_frame(scope_frame)
        self.blockvisit(node.body, scope_frame)
        self.leave_frame(scope_frame)

    def visit_OverlayScope(self, node, frame):
        ctx = self.temporary_identifier()
        self.writeline(f"{ctx} = {self.derive_context(frame)}")
        self.writeline(f"{ctx}.vars = ")
        self.visit(node.context, frame)
        self.push_context_reference(ctx)

        scope_frame = frame.inner(isolated=True)
        scope_frame.symbols.analyze_node(node)
        self.enter_frame(scope_frame)
        self.blockvisit(node.body, scope_frame)
        self.leave_frame(scope_frame)
        self.pop_context_reference()

    def visit_EvalContextModifier(self, node, frame):
        for keyword in node.options:
            self.writeline(f"context.eval_ctx.{keyword.key} = ")
            self.visit(keyword.value, frame)
            try:
                val = keyword.value.as_const(frame.eval_ctx)
            except nodes.Impossible:
                frame.eval_ctx.volatile = True
            else:
                setattr(frame.eval_ctx, keyword.key, val)

    def visit_ScopedEvalContextModifier(self, node, frame):
        old_ctx_name = self.temporary_identifier()
        saved_ctx = frame.eval_ctx.save()
        self.writeline(f"{old_ctx_name} = context.eval_ctx.save()")
        self.visit_EvalContextModifier(node, frame)
        for child in node.body:
            self.visit(child, frame)
        frame.eval_ctx.revert(saved_ctx)
        self.writeline(f"context.eval_ctx.revert({old_ctx_name})")