Commit 81a9e9f3 authored by Artem Baranovskyi's avatar Artem Baranovskyi
Browse files

Final commit.

parents
import re
# generated by scripts/generate_identifier_pattern.py
pattern = re.compile(
r"[\w·̀-ͯ·҃-֑҇-ׇֽֿׁׂׅׄؐ-ًؚ-ٰٟۖ-ۜ۟-۪ۤۧۨ-ܑۭܰ-݊ަ-ް߫-߽߳ࠖ-࠙ࠛ-ࠣࠥ-ࠧࠩ-࡙࠭-࡛࣓-ࣣ࣡-ःऺ-़ा-ॏ॑-ॗॢॣঁ-ঃ়া-ৄেৈো-্ৗৢৣ৾ਁ-ਃ਼ਾ-ੂੇੈੋ-੍ੑੰੱੵઁ-ઃ઼ા-ૅે-ૉો-્ૢૣૺ-૿ଁ-ଃ଼ା-ୄେୈୋ-୍ୖୗୢୣஂா-ூெ-ைொ-்ௗఀ-ఄా-ౄె-ైొ-్ౕౖౢౣಁ-ಃ಼ಾ-ೄೆ-ೈೊ-್ೕೖೢೣഀ-ഃ഻഼ാ-ൄെ-ൈൊ-്ൗൢൣංඃ්ා-ුූෘ-ෟෲෳัิ-ฺ็-๎ັິ-ູົຼ່-ໍ༹༘༙༵༷༾༿ཱ-྄྆྇ྍ-ྗྙ-ྼ࿆ါ-ှၖ-ၙၞ-ၠၢ-ၤၧ-ၭၱ-ၴႂ-ႍႏႚ-ႝ፝-፟ᜒ-᜔ᜲ-᜴ᝒᝓᝲᝳ឴-៓៝᠋-᠍ᢅᢆᢩᤠ-ᤫᤰ-᤻ᨗ-ᨛᩕ-ᩞ᩠-᩿᩼᪰-᪽ᬀ-ᬄ᬴-᭄᭫-᭳ᮀ-ᮂᮡ-ᮭ᯦-᯳ᰤ-᰷᳐-᳔᳒-᳨᳭ᳲ-᳴᳷-᳹᷀-᷹᷻-᷿‿⁀⁔⃐-⃥⃜⃡-⃰℘℮⳯-⵿⳱ⷠ-〪ⷿ-゙゚〯꙯ꙴ-꙽ꚞꚟ꛰꛱ꠂ꠆ꠋꠣ-ꠧꢀꢁꢴ-ꣅ꣠-꣱ꣿꤦ-꤭ꥇ-꥓ꦀ-ꦃ꦳-꧀ꧥꨩ-ꨶꩃꩌꩍꩻ-ꩽꪰꪲ-ꪴꪷꪸꪾ꪿꫁ꫫ-ꫯꫵ꫶ꯣ-ꯪ꯬꯭ﬞ︀-️︠-︯︳︴﹍-﹏_𐇽𐋠𐍶-𐍺𐨁-𐨃𐨅𐨆𐨌-𐨏𐨸-𐨿𐨺𐫦𐫥𐴤-𐽆𐴧-𐽐𑀀-𑀂𑀸-𑁆𑁿-𑂂𑂰-𑂺𑄀-𑄂𑄧-𑄴𑅅𑅆𑅳𑆀-𑆂𑆳-𑇀𑇉-𑇌𑈬-𑈷𑈾𑋟-𑋪𑌀-𑌃𑌻𑌼𑌾-𑍄𑍇𑍈𑍋-𑍍𑍗𑍢𑍣𑍦-𑍬𑍰-𑍴𑐵-𑑆𑑞𑒰-𑓃𑖯-𑖵𑖸-𑗀𑗜𑗝𑘰-𑙀𑚫-𑚷𑜝-𑜫𑠬-𑠺𑨁-𑨊𑨳-𑨹𑨻-𑨾𑩇𑩑-𑩛𑪊-𑪙𑰯-𑰶𑰸-𑰿𑲒-𑲧𑲩-𑲶𑴱-𑴶𑴺𑴼𑴽𑴿-𑵅𑵇𑶊-𑶎𑶐𑶑𑶓-𑶗𑻳-𑻶𖫰-𖫴𖬰-𖬶𖽑-𖽾𖾏-𖾒𛲝𛲞𝅥-𝅩𝅭-𝅲𝅻-𝆂𝆅-𝆋𝆪-𝆭𝉂-𝉄𝨀-𝨶𝨻-𝩬𝩵𝪄𝪛-𝪟𝪡-𝪯𞀀-𞀆𞀈-𞀘𞀛-𞀡𞀣𞀤𞀦-𞣐𞀪-𞣖𞥄-𞥊󠄀-󠇯]+" # noqa: B950
)
import inspect
import typing as t
from functools import WRAPPER_ASSIGNMENTS
from functools import wraps
from .utils import _PassArg
from .utils import pass_eval_context
V = t.TypeVar("V")
def async_variant(normal_func): # type: ignore
def decorator(async_func): # type: ignore
pass_arg = _PassArg.from_obj(normal_func)
need_eval_context = pass_arg is None
if pass_arg is _PassArg.environment:
def is_async(args: t.Any) -> bool:
return t.cast(bool, args[0].is_async)
else:
def is_async(args: t.Any) -> bool:
return t.cast(bool, args[0].environment.is_async)
# Take the doc and annotations from the sync function, but the
# name from the async function. Pallets-Sphinx-Themes
# build_function_directive expects __wrapped__ to point to the
# sync function.
async_func_attrs = ("__module__", "__name__", "__qualname__")
normal_func_attrs = tuple(set(WRAPPER_ASSIGNMENTS).difference(async_func_attrs))
@wraps(normal_func, assigned=normal_func_attrs)
@wraps(async_func, assigned=async_func_attrs, updated=())
def wrapper(*args, **kwargs): # type: ignore
b = is_async(args)
if need_eval_context:
args = args[1:]
if b:
return async_func(*args, **kwargs)
return normal_func(*args, **kwargs)
if need_eval_context:
wrapper = pass_eval_context(wrapper)
wrapper.jinja_async_variant = True # type: ignore[attr-defined]
return wrapper
return decorator
_common_primitives = {int, float, bool, str, list, dict, tuple, type(None)}
async def auto_await(value: t.Union[t.Awaitable["V"], "V"]) -> "V":
# Avoid a costly call to isawaitable
if type(value) in _common_primitives:
return t.cast("V", value)
if inspect.isawaitable(value):
return await t.cast("t.Awaitable[V]", value)
return t.cast("V", value)
async def auto_aiter(
iterable: "t.Union[t.AsyncIterable[V], t.Iterable[V]]",
) -> "t.AsyncIterator[V]":
if hasattr(iterable, "__aiter__"):
async for item in t.cast("t.AsyncIterable[V]", iterable):
yield item
else:
for item in iterable:
yield item
async def auto_to_list(
value: "t.Union[t.AsyncIterable[V], t.Iterable[V]]",
) -> t.List["V"]:
return [x async for x in auto_aiter(value)]
"""The optional bytecode cache system. This is useful if you have very
complex template situations and the compilation of all those templates
slows down your application too much.
Situations where this is useful are often forking web applications that
are initialized on the first request.
"""
import errno
import fnmatch
import marshal
import os
import pickle
import stat
import sys
import tempfile
import typing as t
from hashlib import sha1
from io import BytesIO
from types import CodeType
if t.TYPE_CHECKING:
import typing_extensions as te
from .environment import Environment
class _MemcachedClient(te.Protocol):
def get(self, key: str) -> bytes: ...
def set(
self, key: str, value: bytes, timeout: t.Optional[int] = None
) -> None: ...
bc_version = 5
# Magic bytes to identify Jinja bytecode cache files. Contains the
# Python major and minor version to avoid loading incompatible bytecode
# if a project upgrades its Python version.
bc_magic = (
b"j2"
+ pickle.dumps(bc_version, 2)
+ pickle.dumps((sys.version_info[0] << 24) | sys.version_info[1], 2)
)
class Bucket:
"""Buckets are used to store the bytecode for one template. It's created
and initialized by the bytecode cache and passed to the loading functions.
The buckets get an internal checksum from the cache assigned and use this
to automatically reject outdated cache material. Individual bytecode
cache subclasses don't have to care about cache invalidation.
"""
def __init__(self, environment: "Environment", key: str, checksum: str) -> None:
self.environment = environment
self.key = key
self.checksum = checksum
self.reset()
def reset(self) -> None:
"""Resets the bucket (unloads the bytecode)."""
self.code: t.Optional[CodeType] = None
def load_bytecode(self, f: t.BinaryIO) -> None:
"""Loads bytecode from a file or file like object."""
# make sure the magic header is correct
magic = f.read(len(bc_magic))
if magic != bc_magic:
self.reset()
return
# the source code of the file changed, we need to reload
checksum = pickle.load(f)
if self.checksum != checksum:
self.reset()
return
# if marshal_load fails then we need to reload
try:
self.code = marshal.load(f)
except (EOFError, ValueError, TypeError):
self.reset()
return
def write_bytecode(self, f: t.IO[bytes]) -> None:
"""Dump the bytecode into the file or file like object passed."""
if self.code is None:
raise TypeError("can't write empty bucket")
f.write(bc_magic)
pickle.dump(self.checksum, f, 2)
marshal.dump(self.code, f)
def bytecode_from_string(self, string: bytes) -> None:
"""Load bytecode from bytes."""
self.load_bytecode(BytesIO(string))
def bytecode_to_string(self) -> bytes:
"""Return the bytecode as bytes."""
out = BytesIO()
self.write_bytecode(out)
return out.getvalue()
class BytecodeCache:
"""To implement your own bytecode cache you have to subclass this class
and override :meth:`load_bytecode` and :meth:`dump_bytecode`. Both of
these methods are passed a :class:`~jinja2.bccache.Bucket`.
A very basic bytecode cache that saves the bytecode on the file system::
from os import path
class MyCache(BytecodeCache):
def __init__(self, directory):
self.directory = directory
def load_bytecode(self, bucket):
filename = path.join(self.directory, bucket.key)
if path.exists(filename):
with open(filename, 'rb') as f:
bucket.load_bytecode(f)
def dump_bytecode(self, bucket):
filename = path.join(self.directory, bucket.key)
with open(filename, 'wb') as f:
bucket.write_bytecode(f)
A more advanced version of a filesystem based bytecode cache is part of
Jinja.
"""
def load_bytecode(self, bucket: Bucket) -> None:
"""Subclasses have to override this method to load bytecode into a
bucket. If they are not able to find code in the cache for the
bucket, it must not do anything.
"""
raise NotImplementedError()
def dump_bytecode(self, bucket: Bucket) -> None:
"""Subclasses have to override this method to write the bytecode
from a bucket back to the cache. If it unable to do so it must not
fail silently but raise an exception.
"""
raise NotImplementedError()
def clear(self) -> None:
"""Clears the cache. This method is not used by Jinja but should be
implemented to allow applications to clear the bytecode cache used
by a particular environment.
"""
def get_cache_key(
self, name: str, filename: t.Optional[t.Union[str]] = None
) -> str:
"""Returns the unique hash key for this template name."""
hash = sha1(name.encode("utf-8"))
if filename is not None:
hash.update(f"|{filename}".encode())
return hash.hexdigest()
def get_source_checksum(self, source: str) -> str:
"""Returns a checksum for the source."""
return sha1(source.encode("utf-8")).hexdigest()
def get_bucket(
self,
environment: "Environment",
name: str,
filename: t.Optional[str],
source: str,
) -> Bucket:
"""Return a cache bucket for the given template. All arguments are
mandatory but filename may be `None`.
"""
key = self.get_cache_key(name, filename)
checksum = self.get_source_checksum(source)
bucket = Bucket(environment, key, checksum)
self.load_bytecode(bucket)
return bucket
def set_bucket(self, bucket: Bucket) -> None:
"""Put the bucket into the cache."""
self.dump_bytecode(bucket)
class FileSystemBytecodeCache(BytecodeCache):
"""A bytecode cache that stores bytecode on the filesystem. It accepts
two arguments: The directory where the cache items are stored and a
pattern string that is used to build the filename.
If no directory is specified a default cache directory is selected. On
Windows the user's temp directory is used, on UNIX systems a directory
is created for the user in the system temp directory.
The pattern can be used to have multiple separate caches operate on the
same directory. The default pattern is ``'__jinja2_%s.cache'``. ``%s``
is replaced with the cache key.
>>> bcc = FileSystemBytecodeCache('/tmp/jinja_cache', '%s.cache')
This bytecode cache supports clearing of the cache using the clear method.
"""
def __init__(
self, directory: t.Optional[str] = None, pattern: str = "__jinja2_%s.cache"
) -> None:
if directory is None:
directory = self._get_default_cache_dir()
self.directory = directory
self.pattern = pattern
def _get_default_cache_dir(self) -> str:
def _unsafe_dir() -> "te.NoReturn":
raise RuntimeError(
"Cannot determine safe temp directory. You "
"need to explicitly provide one."
)
tmpdir = tempfile.gettempdir()
# On windows the temporary directory is used specific unless
# explicitly forced otherwise. We can just use that.
if os.name == "nt":
return tmpdir
if not hasattr(os, "getuid"):
_unsafe_dir()
dirname = f"_jinja2-cache-{os.getuid()}"
actual_dir = os.path.join(tmpdir, dirname)
try:
os.mkdir(actual_dir, stat.S_IRWXU)
except OSError as e:
if e.errno != errno.EEXIST:
raise
try:
os.chmod(actual_dir, stat.S_IRWXU)
actual_dir_stat = os.lstat(actual_dir)
if (
actual_dir_stat.st_uid != os.getuid()
or not stat.S_ISDIR(actual_dir_stat.st_mode)
or stat.S_IMODE(actual_dir_stat.st_mode) != stat.S_IRWXU
):
_unsafe_dir()
except OSError as e:
if e.errno != errno.EEXIST:
raise
actual_dir_stat = os.lstat(actual_dir)
if (
actual_dir_stat.st_uid != os.getuid()
or not stat.S_ISDIR(actual_dir_stat.st_mode)
or stat.S_IMODE(actual_dir_stat.st_mode) != stat.S_IRWXU
):
_unsafe_dir()
return actual_dir
def _get_cache_filename(self, bucket: Bucket) -> str:
return os.path.join(self.directory, self.pattern % (bucket.key,))
def load_bytecode(self, bucket: Bucket) -> None:
filename = self._get_cache_filename(bucket)
# Don't test for existence before opening the file, since the
# file could disappear after the test before the open.
try:
f = open(filename, "rb")
except (FileNotFoundError, IsADirectoryError, PermissionError):
# PermissionError can occur on Windows when an operation is
# in progress, such as calling clear().
return
with f:
bucket.load_bytecode(f)
def dump_bytecode(self, bucket: Bucket) -> None:
# Write to a temporary file, then rename to the real name after
# writing. This avoids another process reading the file before
# it is fully written.
name = self._get_cache_filename(bucket)
f = tempfile.NamedTemporaryFile(
mode="wb",
dir=os.path.dirname(name),
prefix=os.path.basename(name),
suffix=".tmp",
delete=False,
)
def remove_silent() -> None:
try:
os.remove(f.name)
except OSError:
# Another process may have called clear(). On Windows,
# another program may be holding the file open.
pass
try:
with f:
bucket.write_bytecode(f)
except BaseException:
remove_silent()
raise
try:
os.replace(f.name, name)
except OSError:
# Another process may have called clear(). On Windows,
# another program may be holding the file open.
remove_silent()
except BaseException:
remove_silent()
raise
def clear(self) -> None:
# imported lazily here because google app-engine doesn't support
# write access on the file system and the function does not exist
# normally.
from os import remove
files = fnmatch.filter(os.listdir(self.directory), self.pattern % ("*",))
for filename in files:
try:
remove(os.path.join(self.directory, filename))
except OSError:
pass
class MemcachedBytecodeCache(BytecodeCache):
"""This class implements a bytecode cache that uses a memcache cache for
storing the information. It does not enforce a specific memcache library
(tummy's memcache or cmemcache) but will accept any class that provides
the minimal interface required.
Libraries compatible with this class:
- `cachelib <https://github.com/pallets/cachelib>`_
- `python-memcached <https://pypi.org/project/python-memcached/>`_
(Unfortunately the django cache interface is not compatible because it
does not support storing binary data, only text. You can however pass
the underlying cache client to the bytecode cache which is available
as `django.core.cache.cache._client`.)
The minimal interface for the client passed to the constructor is this:
.. class:: MinimalClientInterface
.. method:: set(key, value[, timeout])
Stores the bytecode in the cache. `value` is a string and
`timeout` the timeout of the key. If timeout is not provided
a default timeout or no timeout should be assumed, if it's
provided it's an integer with the number of seconds the cache
item should exist.
.. method:: get(key)
Returns the value for the cache key. If the item does not
exist in the cache the return value must be `None`.
The other arguments to the constructor are the prefix for all keys that
is added before the actual cache key and the timeout for the bytecode in
the cache system. We recommend a high (or no) timeout.
This bytecode cache does not support clearing of used items in the cache.
The clear method is a no-operation function.
.. versionadded:: 2.7
Added support for ignoring memcache errors through the
`ignore_memcache_errors` parameter.
"""
def __init__(
self,
client: "_MemcachedClient",
prefix: str = "jinja2/bytecode/",
timeout: t.Optional[int] = None,
ignore_memcache_errors: bool = True,
):
self.client = client
self.prefix = prefix
self.timeout = timeout
self.ignore_memcache_errors = ignore_memcache_errors
def load_bytecode(self, bucket: Bucket) -> None:
try:
code = self.client.get(self.prefix + bucket.key)
except Exception:
if not self.ignore_memcache_errors:
raise
else:
bucket.bytecode_from_string(code)
def dump_bytecode(self, bucket: Bucket) -> None:
key = self.prefix + bucket.key
value = bucket.bytecode_to_string()
try:
if self.timeout is not None:
self.client.set(key, value, self.timeout)
else:
self.client.set(key, value)
except Exception:
if not self.ignore_memcache_errors:
raise
"""Compiles nodes from the parser into Python code."""
import typing as t
from contextlib import contextmanager
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 _PassArg
from .utils import concat
from .visitor import NodeVisitor
if t.TYPE_CHECKING:
import typing_extensions as te
from .environment import Environment
F = t.TypeVar("F", bound=t.Callable[..., t.Any])
operators = {
"eq": "==",
"ne": "!=",
"gt": ">",
"gteq": ">=",
"lt": "<",
"lteq": "<=",
"in": "in",
"notin": "not in",
}
def optimizeconst(f: F) -> F:
def new_func(
self: "CodeGenerator", node: nodes.Expr, frame: "Frame", **kwargs: t.Any
) -> t.Any:
# Only optimize if the frame is not volatile
if self.optimizer is not None 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(t.cast(F, new_func), f)
def _make_binop(op: str) -> t.Callable[["CodeGenerator", nodes.BinExpr, "Frame"], None]:
@optimizeconst
def visitor(self: "CodeGenerator", node: nodes.BinExpr, frame: Frame) -> None:
if (
self.environment.sandboxed and op in self.environment.intercepted_binops # type: ignore
):
self.write(f"environment.call_binop(context, {op!r}, ")
self.visit(node.left, frame)
self.write(", ")
self.visit(node.right, frame)
else:
self.write("(")
self.visit(node.left, frame)
self.write(f" {op} ")
self.visit(node.right, frame)
self.write(")")
return visitor
def _make_unop(
op: str,
) -> t.Callable[["CodeGenerator", nodes.UnaryExpr, "Frame"], None]:
@optimizeconst
def visitor(self: "CodeGenerator", node: nodes.UnaryExpr, frame: Frame) -> None:
if (
self.environment.sandboxed and op in self.environment.intercepted_unops # type: ignore
):
self.write(f"environment.call_unop(context, {op!r}, ")
self.visit(node.node, frame)
else:
self.write("(" + op)
self.visit(node.node, frame)
self.write(")")
return visitor
def generate(
node: nodes.Template,
environment: "Environment",
name: t.Optional[str],
filename: t.Optional[str],
stream: t.Optional[t.TextIO] = None,
defer_init: bool = False,
optimized: bool = True,
) -> t.Optional[str]:
"""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() # type: ignore
return None
def has_safe_repr(value: t.Any) -> bool:
"""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: # noqa E721
return all(has_safe_repr(k) and has_safe_repr(v) for k, v in value.items())
return False
def find_undeclared(
nodes: t.Iterable[nodes.Node], names: t.Iterable[str]
) -> t.Set[str]:
"""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: t.Union[nodes.Macro, nodes.CallBlock]) -> None:
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: EvalContext,
parent: t.Optional["Frame"] = None,
level: t.Optional[int] = None,
) -> None:
self.eval_ctx = eval_ctx
# the parent of this frame
self.parent = parent
if parent is None:
self.symbols = Symbols(level=level)
# in some dynamic inheritance situations the compiler needs to add
# write tests around output statements.
self.require_output_check = False
# 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: t.Optional[str] = None
# the name of the block we're in, otherwise None.
self.block: t.Optional[str] = None
else:
self.symbols = Symbols(parent.symbols, level=level)
self.require_output_check = parent.require_output_check
self.buffer = parent.buffer
self.block = parent.block
# 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
# variables set inside of loops and blocks should not affect outer frames,
# but they still needs to be kept track of as part of the active context.
self.loop_frame = False
self.block_frame = False
# track whether the frame is being used in an if-statement or conditional
# expression as it determines which errors should be raised during runtime
# or compile time.
self.soft_frame = False
def copy(self) -> "Frame":
"""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: bool = False) -> "Frame":
"""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) -> "Frame":
"""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 and conditional
expressions.
"""
rv = self.copy()
rv.rootlevel = False
rv.soft_frame = True
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) -> None:
self.filters: t.Set[str] = set()
self.tests: t.Set[str] = set()
def visit_Filter(self, node: nodes.Filter) -> None:
self.generic_visit(node)
self.filters.add(node.name)
def visit_Test(self, node: nodes.Test) -> None:
self.generic_visit(node)
self.tests.add(node.name)
def visit_Block(self, node: nodes.Block) -> None:
"""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: t.Iterable[str]) -> None:
self.names = set(names)
self.undeclared: t.Set[str] = set()
def visit_Name(self, node: nodes.Name) -> None:
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: nodes.Block) -> None:
"""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: "Environment",
name: t.Optional[str],
filename: t.Optional[str],
stream: t.Optional[t.TextIO] = None,
defer_init: bool = False,
optimized: bool = True,
) -> None:
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.optimizer: t.Optional[Optimizer] = None
if optimized:
self.optimizer = Optimizer(environment)
# aliases for imports
self.import_aliases: t.Dict[str, str] = {}
# a registry for all blocks. Because blocks are moved out
# into the global python scope they are registered here
self.blocks: t.Dict[str, nodes.Block] = {}
# 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: t.Dict[str, str] = {}
self.filters: t.Dict[str, str] = {}
# the debug information
self.debug_info: t.List[t.Tuple[int, int]] = []
self._write_debug_info: t.Optional[int] = 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: t.List[t.Set[str]] = []
# Tracks parameter definition blocks
self._param_def_block: t.List[t.Set[str]] = []
# Tracks the current context.
self._context_reference_stack = ["context"]
@property
def optimized(self) -> bool:
return self.optimizer is not None
# -- Various compilation helpers
def fail(self, msg: str, lineno: int) -> "te.NoReturn":
"""Fail with a :exc:`TemplateAssertionError`."""
raise TemplateAssertionError(msg, lineno, self.name, self.filename)
def temporary_identifier(self) -> str:
"""Get a new unique identifier."""
self._last_identifier += 1
return f"t_{self._last_identifier}"
def buffer(self, frame: Frame) -> None:
"""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: Frame, force_unescaped: bool = False
) -> None:
"""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) -> None:
"""Indent by one."""
self._indentation += 1
def outdent(self, step: int = 1) -> None:
"""Outdent by step."""
self._indentation -= step
def start_write(self, frame: Frame, node: t.Optional[nodes.Node] = None) -> 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: Frame) -> None:
"""End the writing process started by `start_write`."""
if frame.buffer is not None:
self.write(")")
def simple_write(
self, s: str, frame: Frame, node: t.Optional[nodes.Node] = None
) -> 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: t.Iterable[nodes.Node], frame: Frame) -> None:
"""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: str) -> None:
"""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: str, node: t.Optional[nodes.Node] = None, extra: int = 0
) -> None:
"""Combination of newline and write."""
self.newline(node, extra)
self.write(x)
def newline(self, node: t.Optional[nodes.Node] = None, extra: int = 0) -> None:
"""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: t.Union[nodes.Call, nodes.Filter, nodes.Test],
frame: Frame,
extra_kwargs: t.Optional[t.Mapping[str, t.Any]] = None,
) -> 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 = any(
is_python_keyword(t.cast(str, k))
for k in chain((x.key for x in node.kwargs), extra_kwargs or ())
)
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: t.Iterable[nodes.Node]) -> None:
"""Find all filter and test names used in the template and
assign them to variables in the compiled namespace. Checking
that the names are registered with the environment is done when
compiling the Filter and Test nodes. If the node is in an If or
CondExpr node, the check is done at runtime instead.
.. versionchanged:: 3.0
Filters and tests in If and CondExpr nodes are checked at
runtime instead of compile time.
"""
visitor = DependencyFinderVisitor()
for node in nodes:
visitor.visit(node)
for id_map, names, dependency in (
(self.filters, visitor.filters, "filters"),
(
self.tests,
visitor.tests,
"tests",
),
):
for name in sorted(names):
if name not in id_map:
id_map[name] = self.temporary_identifier()
# add check during runtime that dependencies used inside of executed
# blocks are defined, as this step may be skipped during compile time
self.writeline("try:")
self.indent()
self.writeline(f"{id_map[name]} = environment.{dependency}[{name!r}]")
self.outdent()
self.writeline("except KeyError:")
self.indent()
self.writeline("@internalcode")
self.writeline(f"def {id_map[name]}(*unused):")
self.indent()
self.writeline(
f'raise TemplateRuntimeError("No {dependency[:-1]}'
f' named {name!r} found.")'
)
self.outdent()
self.outdent()
def enter_frame(self, frame: Frame) -> None:
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: Frame, with_python_scope: bool = False) -> None:
if not with_python_scope:
undefs = []
for target in frame.symbols.loads:
undefs.append(target)
if undefs:
self.writeline(f"{' = '.join(undefs)} = missing")
def choose_async(self, async_value: str = "async ", sync_value: str = "") -> str:
return async_value if self.environment.is_async else sync_value
def func(self, name: str) -> str:
return f"{self.choose_async()}def {name}"
def macro_body(
self, node: t.Union[nodes.Macro, nodes.CallBlock], frame: Frame
) -> t.Tuple[Frame, MacroRef]:
"""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: MacroRef, frame: Frame) -> None:
"""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: nodes.Node) -> str:
"""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: Frame) -> str:
items_kv = ", ".join(
f"{name!r}: {target}"
for name, target in frame.symbols.dump_stores().items()
)
return f"{{{items_kv}}}"
def write_commons(self) -> None:
"""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")
self.writeline("concat = environment.concat")
# 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: Frame) -> None:
"""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) -> None:
"""Pops the current parameter definitions set."""
self._param_def_block.pop()
def mark_parameter_stored(self, target: str) -> None:
"""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: str) -> None:
self._context_reference_stack.append(target)
def pop_context_reference(self) -> None:
self._context_reference_stack.pop()
def get_context_ref(self) -> str:
return self._context_reference_stack[-1]
def get_resolve_func(self) -> str:
target = self._context_reference_stack[-1]
if target == "context":
return "resolve"
return f"{target}.resolve"
def derive_context(self, frame: Frame) -> str:
return f"{self.get_context_ref()}.derived({self.dump_local_context(frame)})"
def parameter_is_undeclared(self, target: str) -> bool:
"""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) -> None:
"""Pushes a new layer for assignment tracking."""
self._assign_stack.append(set())
def pop_assign_tracking(self, frame: Frame) -> None:
"""Pops the topmost level for assignment tracking and updates the
context variables if necessary.
"""
vars = self._assign_stack.pop()
if (
not frame.block_frame
and not frame.loop_frame
and 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)
if frame.loop_frame:
self.writeline(f"_loop_vars[{name!r}] = {ref}")
return
if frame.block_frame:
self.writeline(f"_block_vars[{name!r}] = {ref}")
return
self.writeline(f"context.vars[{name!r}] = {ref}")
else:
if frame.loop_frame:
self.writeline("_loop_vars.update({")
elif frame.block_frame:
self.writeline("_block_vars.update({")
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 not frame.block_frame and not frame.loop_frame and 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: nodes.Template, frame: t.Optional[Frame] = None
) -> None:
assert frame is None, "no root frame allowed"
eval_ctx = EvalContext(self.environment, self.name)
from .runtime import async_exported
from .runtime import exported
if self.environment.is_async:
exported_names = sorted(exported + async_exported)
else:
exported_names = sorted(exported)
self.writeline("from jinja2.runtime import " + ", ".join(exported_names))
# 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:
self.writeline(
"async for 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)
block_frame.block_frame = True
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.writeline("_block_vars = {}")
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: nodes.Block, frame: Frame) -> None:
"""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 node.required:
self.writeline(f"if len(context.blocks[{node.name!r}]) <= 1:", node)
self.indent()
self.writeline(
f'raise TemplateRuntimeError("Required block {node.name!r} not found")',
node,
)
self.outdent()
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:
self.writeline(
f"{self.choose_async()}for event in"
f" 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: nodes.Extends, frame: Frame) -> None:
"""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: nodes.Include, frame: Frame) -> None:
"""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:
self.writeline(
f"{self.choose_async()}for 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 _import_common(
self, node: t.Union[nodes.Import, nodes.FromImport], frame: Frame
) -> None:
self.write(f"{self.choose_async('await ')}environment.get_template(")
self.visit(node.template, frame)
self.write(f", {self.name!r}).")
if node.with_context:
f_name = f"make_module{self.choose_async('_async')}"
self.write(
f"{f_name}(context.get_all(), True, {self.dump_local_context(frame)})"
)
else:
self.write(f"_get_default_module{self.choose_async('_async')}(context)")
def visit_Import(self, node: nodes.Import, frame: Frame) -> None:
"""Visit regular imports."""
self.writeline(f"{frame.symbols.ref(node.target)} = ", node)
if frame.toplevel:
self.write(f"context.vars[{node.target!r}] = ")
self._import_common(node, frame)
if frame.toplevel and not node.target.startswith("_"):
self.writeline(f"context.exported_vars.discard({node.target!r})")
def visit_FromImport(self, node: nodes.FromImport, frame: Frame) -> None:
"""Visit named imports."""
self.newline(node)
self.write("included_template = ")
self._import_common(node, frame)
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: nodes.For, frame: Frame) -> None:
loop_frame = frame.inner()
loop_frame.loop_frame = True
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 if the body is a scoped block.
extended_loop = (
node.recursive
or "loop"
in find_undeclared(node.iter_child_nodes(only=("body",)), ("loop",))
or any(block.scoped for block in node.find_all(nodes.Block))
)
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(self.choose_async("async for ", "for "))
self.visit(node.target, loop_frame)
self.write(" in ")
self.write(self.choose_async("auto_aiter(fiter)", "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(self.choose_async("async for ", "for "), node)
self.visit(node.target, loop_frame)
if extended_loop:
self.write(f", {loop_ref} in {self.choose_async('Async')}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.writeline("_loop_vars = {}")
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)
self.write(f"{self.choose_async('await ')}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)
# at the end of the iteration, clear any assignments made in the
# loop from the top level
if self._assign_stack:
self._assign_stack[-1].difference_update(loop_frame.symbols.stores)
def visit_If(self, node: nodes.If, frame: Frame) -> None:
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: nodes.Macro, frame: Frame) -> None:
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: nodes.CallBlock, frame: Frame) -> None:
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: nodes.FilterBlock, frame: Frame) -> None:
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: nodes.With, frame: Frame) -> None:
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: nodes.ExprStmt, frame: Frame) -> None:
self.newline(node)
self.visit(node.node, frame)
class _FinalizeInfo(t.NamedTuple):
const: t.Optional[t.Callable[..., str]]
src: t.Optional[str]
@staticmethod
def _default_finalize(value: t.Any) -> t.Any:
"""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.
"""
return str(value)
_finalize: t.Optional[_FinalizeInfo] = None
def _make_finalize(self) -> _FinalizeInfo:
"""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: t.Optional[t.Callable[..., t.Any]]
finalize = default = self._default_finalize
src = None
if self.environment.finalize:
src = "environment.finalize("
env_finalize = self.environment.finalize
pass_arg = {
_PassArg.context: "context",
_PassArg.eval_context: "context.eval_ctx",
_PassArg.environment: "environment",
}.get(
_PassArg.from_obj(env_finalize) # type: ignore
)
finalize = None
if pass_arg is None:
def finalize(value: t.Any) -> t.Any: # noqa: F811
return default(env_finalize(value))
else:
src = f"{src}{pass_arg}, "
if pass_arg == "environment":
def finalize(value: t.Any) -> t.Any: # noqa: F811
return default(env_finalize(self.environment, value))
self._finalize = self._FinalizeInfo(finalize, src)
return self._finalize
def _output_const_repr(self, group: t.Iterable[t.Any]) -> str:
"""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: nodes.Expr, frame: Frame, finalize: _FinalizeInfo
) -> str:
"""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) # type: ignore
def _output_child_pre(
self, node: nodes.Expr, frame: Frame, finalize: _FinalizeInfo
) -> None:
"""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: nodes.Expr, frame: Frame, finalize: _FinalizeInfo
) -> None:
"""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: nodes.Output, frame: Frame) -> None:
# 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: t.List[t.Union[t.List[t.Any], nodes.Expr]] = []
# 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: nodes.Assign, frame: Frame) -> None:
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: nodes.AssignBlock, frame: Frame) -> None:
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: nodes.Name, frame: Frame) -> None:
if node.ctx == "store" and (
frame.toplevel or frame.loop_frame or frame.block_frame
):
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: nodes.NSRef, frame: Frame) -> None:
# 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: nodes.Const, frame: Frame) -> None:
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: nodes.TemplateData, frame: Frame) -> None:
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: nodes.Tuple, frame: Frame) -> None:
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: nodes.List, frame: Frame) -> None:
self.write("[")
for idx, item in enumerate(node.items):
if idx:
self.write(", ")
self.visit(item, frame)
self.write("]")
def visit_Dict(self, node: nodes.Dict, frame: Frame) -> None:
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("}")
visit_Add = _make_binop("+")
visit_Sub = _make_binop("-")
visit_Mul = _make_binop("*")
visit_Div = _make_binop("/")
visit_FloorDiv = _make_binop("//")
visit_Pow = _make_binop("**")
visit_Mod = _make_binop("%")
visit_And = _make_binop("and")
visit_Or = _make_binop("or")
visit_Pos = _make_unop("+")
visit_Neg = _make_unop("-")
visit_Not = _make_unop("not ")
@optimizeconst
def visit_Concat(self, node: nodes.Concat, frame: Frame) -> None:
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: nodes.Compare, frame: Frame) -> None:
self.write("(")
self.visit(node.expr, frame)
for op in node.ops:
self.visit(op, frame)
self.write(")")
def visit_Operand(self, node: nodes.Operand, frame: Frame) -> None:
self.write(f" {operators[node.op]} ")
self.visit(node.expr, frame)
@optimizeconst
def visit_Getattr(self, node: nodes.Getattr, frame: Frame) -> None:
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: nodes.Getitem, frame: Frame) -> None:
# 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: nodes.Slice, frame: Frame) -> None:
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)
@contextmanager
def _filter_test_common(
self, node: t.Union[nodes.Filter, nodes.Test], frame: Frame, is_filter: bool
) -> t.Iterator[None]:
if self.environment.is_async:
self.write("(await auto_await(")
if is_filter:
self.write(f"{self.filters[node.name]}(")
func = self.environment.filters.get(node.name)
else:
self.write(f"{self.tests[node.name]}(")
func = self.environment.tests.get(node.name)
# When inside an If or CondExpr frame, allow the filter to be
# undefined at compile time and only raise an error if it's
# actually called at runtime. See pull_dependencies.
if func is None and not frame.soft_frame:
type_name = "filter" if is_filter else "test"
self.fail(f"No {type_name} named {node.name!r}.", node.lineno)
pass_arg = {
_PassArg.context: "context",
_PassArg.eval_context: "context.eval_ctx",
_PassArg.environment: "environment",
}.get(
_PassArg.from_obj(func) # type: ignore
)
if pass_arg is not None:
self.write(f"{pass_arg}, ")
# Back to the visitor function to handle visiting the target of
# the filter or test.
yield
self.signature(node, frame)
self.write(")")
if self.environment.is_async:
self.write("))")
@optimizeconst
def visit_Filter(self, node: nodes.Filter, frame: Frame) -> None:
with self._filter_test_common(node, frame, True):
# 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})")
@optimizeconst
def visit_Test(self, node: nodes.Test, frame: Frame) -> None:
with self._filter_test_common(node, frame, False):
self.visit(node.node, frame)
@optimizeconst
def visit_CondExpr(self, node: nodes.CondExpr, frame: Frame) -> None:
frame = frame.soft()
def write_expr2() -> None:
if node.expr2 is not None:
self.visit(node.expr2, frame)
return
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: nodes.Call, frame: Frame, forward_caller: bool = False
) -> None:
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
loop_kwargs = {"_loop_vars": "_loop_vars"} if frame.loop_frame else {}
block_kwargs = {"_block_vars": "_block_vars"} if frame.block_frame else {}
if extra_kwargs:
extra_kwargs.update(loop_kwargs, **block_kwargs)
elif loop_kwargs or block_kwargs:
extra_kwargs = dict(loop_kwargs, **block_kwargs)
self.signature(node, frame, extra_kwargs)
self.write(")")
if self.environment.is_async:
self.write("))")
def visit_Keyword(self, node: nodes.Keyword, frame: Frame) -> None:
self.write(node.key + "=")
self.visit(node.value, frame)
# -- Unused nodes for extensions
def visit_MarkSafe(self, node: nodes.MarkSafe, frame: Frame) -> None:
self.write("Markup(")
self.visit(node.expr, frame)
self.write(")")
def visit_MarkSafeIfAutoescape(
self, node: nodes.MarkSafeIfAutoescape, frame: Frame
) -> None:
self.write("(Markup if context.eval_ctx.autoescape else identity)(")
self.visit(node.expr, frame)
self.write(")")
def visit_EnvironmentAttribute(
self, node: nodes.EnvironmentAttribute, frame: Frame
) -> None:
self.write("environment." + node.name)
def visit_ExtensionAttribute(
self, node: nodes.ExtensionAttribute, frame: Frame
) -> None:
self.write(f"environment.extensions[{node.identifier!r}].{node.name}")
def visit_ImportedName(self, node: nodes.ImportedName, frame: Frame) -> None:
self.write(self.import_aliases[node.importname])
def visit_InternalName(self, node: nodes.InternalName, frame: Frame) -> None:
self.write(node.name)
def visit_ContextReference(
self, node: nodes.ContextReference, frame: Frame
) -> None:
self.write("context")
def visit_DerivedContextReference(
self, node: nodes.DerivedContextReference, frame: Frame
) -> None:
self.write(self.derive_context(frame))
def visit_Continue(self, node: nodes.Continue, frame: Frame) -> None:
self.writeline("continue", node)
def visit_Break(self, node: nodes.Break, frame: Frame) -> None:
self.writeline("break", node)
def visit_Scope(self, node: nodes.Scope, frame: Frame) -> None:
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: nodes.OverlayScope, frame: Frame) -> None:
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: nodes.EvalContextModifier, frame: Frame
) -> None:
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: nodes.ScopedEvalContextModifier, frame: Frame
) -> None:
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})")
#: list of lorem ipsum words used by the lipsum() helper function
LOREM_IPSUM_WORDS = """\
a ac accumsan ad adipiscing aenean aliquam aliquet amet ante aptent arcu at
auctor augue bibendum blandit class commodo condimentum congue consectetuer
consequat conubia convallis cras cubilia cum curabitur curae cursus dapibus
diam dictum dictumst dignissim dis dolor donec dui duis egestas eget eleifend
elementum elit enim erat eros est et etiam eu euismod facilisi facilisis fames
faucibus felis fermentum feugiat fringilla fusce gravida habitant habitasse hac
hendrerit hymenaeos iaculis id imperdiet in inceptos integer interdum ipsum
justo lacinia lacus laoreet lectus leo libero ligula litora lobortis lorem
luctus maecenas magna magnis malesuada massa mattis mauris metus mi molestie
mollis montes morbi mus nam nascetur natoque nec neque netus nibh nisi nisl non
nonummy nostra nulla nullam nunc odio orci ornare parturient pede pellentesque
penatibus per pharetra phasellus placerat platea porta porttitor posuere
potenti praesent pretium primis proin pulvinar purus quam quis quisque rhoncus
ridiculus risus rutrum sagittis sapien scelerisque sed sem semper senectus sit
sociis sociosqu sodales sollicitudin suscipit suspendisse taciti tellus tempor
tempus tincidunt torquent tortor tristique turpis ullamcorper ultrices
ultricies urna ut varius vehicula vel velit venenatis vestibulum vitae vivamus
viverra volutpat vulputate"""
import sys
import typing as t
from types import CodeType
from types import TracebackType
from .exceptions import TemplateSyntaxError
from .utils import internal_code
from .utils import missing
if t.TYPE_CHECKING:
from .runtime import Context
def rewrite_traceback_stack(source: t.Optional[str] = None) -> BaseException:
"""Rewrite the current exception to replace any tracebacks from
within compiled template code with tracebacks that look like they
came from the template source.
This must be called within an ``except`` block.
:param source: For ``TemplateSyntaxError``, the original source if
known.
:return: The original exception with the rewritten traceback.
"""
_, exc_value, tb = sys.exc_info()
exc_value = t.cast(BaseException, exc_value)
tb = t.cast(TracebackType, tb)
if isinstance(exc_value, TemplateSyntaxError) and not exc_value.translated:
exc_value.translated = True
exc_value.source = source
# Remove the old traceback, otherwise the frames from the
# compiler still show up.
exc_value.with_traceback(None)
# Outside of runtime, so the frame isn't executing template
# code, but it still needs to point at the template.
tb = fake_traceback(
exc_value, None, exc_value.filename or "<unknown>", exc_value.lineno
)
else:
# Skip the frame for the render function.
tb = tb.tb_next
stack = []
# Build the stack of traceback object, replacing any in template
# code with the source file and line information.
while tb is not None:
# Skip frames decorated with @internalcode. These are internal
# calls that aren't useful in template debugging output.
if tb.tb_frame.f_code in internal_code:
tb = tb.tb_next
continue
template = tb.tb_frame.f_globals.get("__jinja_template__")
if template is not None:
lineno = template.get_corresponding_lineno(tb.tb_lineno)
fake_tb = fake_traceback(exc_value, tb, template.filename, lineno)
stack.append(fake_tb)
else:
stack.append(tb)
tb = tb.tb_next
tb_next = None
# Assign tb_next in reverse to avoid circular references.
for tb in reversed(stack):
tb.tb_next = tb_next
tb_next = tb
return exc_value.with_traceback(tb_next)
def fake_traceback( # type: ignore
exc_value: BaseException, tb: t.Optional[TracebackType], filename: str, lineno: int
) -> TracebackType:
"""Produce a new traceback object that looks like it came from the
template source instead of the compiled code. The filename, line
number, and location name will point to the template, and the local
variables will be the current template context.
:param exc_value: The original exception to be re-raised to create
the new traceback.
:param tb: The original traceback to get the local variables and
code info from.
:param filename: The template filename.
:param lineno: The line number in the template source.
"""
if tb is not None:
# Replace the real locals with the context that would be
# available at that point in the template.
locals = get_template_locals(tb.tb_frame.f_locals)
locals.pop("__jinja_exception__", None)
else:
locals = {}
globals = {
"__name__": filename,
"__file__": filename,
"__jinja_exception__": exc_value,
}
# Raise an exception at the correct line number.
code: CodeType = compile(
"\n" * (lineno - 1) + "raise __jinja_exception__", filename, "exec"
)
# Build a new code object that points to the template file and
# replaces the location with a block name.
location = "template"
if tb is not None:
function = tb.tb_frame.f_code.co_name
if function == "root":
location = "top-level template code"
elif function.startswith("block_"):
location = f"block {function[6:]!r}"
if sys.version_info >= (3, 8):
code = code.replace(co_name=location)
else:
code = CodeType(
code.co_argcount,
code.co_kwonlyargcount,
code.co_nlocals,
code.co_stacksize,
code.co_flags,
code.co_code,
code.co_consts,
code.co_names,
code.co_varnames,
code.co_filename,
location,
code.co_firstlineno,
code.co_lnotab,
code.co_freevars,
code.co_cellvars,
)
# Execute the new code, which is guaranteed to raise, and return
# the new traceback without this frame.
try:
exec(code, globals, locals)
except BaseException:
return sys.exc_info()[2].tb_next # type: ignore
def get_template_locals(real_locals: t.Mapping[str, t.Any]) -> t.Dict[str, t.Any]:
"""Based on the runtime locals, get the context that would be
available at that point in the template.
"""
# Start with the current template context.
ctx: "t.Optional[Context]" = real_locals.get("context")
if ctx is not None:
data: t.Dict[str, t.Any] = ctx.get_all().copy()
else:
data = {}
# Might be in a derived context that only sets local variables
# rather than pushing a context. Local variables follow the scheme
# l_depth_name. Find the highest-depth local that has a value for
# each name.
local_overrides: t.Dict[str, t.Tuple[int, t.Any]] = {}
for name, value in real_locals.items():
if not name.startswith("l_") or value is missing:
# Not a template variable, or no longer relevant.
continue
try:
_, depth_str, name = name.split("_", 2)
depth = int(depth_str)
except ValueError:
continue
cur_depth = local_overrides.get(name, (-1,))[0]
if cur_depth < depth:
local_overrides[name] = (depth, value)
# Modify the context with any derived context.
for name, (_, value) in local_overrides.items():
if value is missing:
data.pop(name, None)
else:
data[name] = value
return data
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