def _compile_expr(self, expr, raise_on_missing=False):
""" Compiles a purported Python expression to compiled code, verifies
that it's safe (according to safe_eval's semantics) and alter its
variable references to access values data instead
:param expr: string
"""
namespace_expr = super()._compile_expr(expr, raise_on_missing=raise_on_missing)
assert_valid_codeobj(_SAFE_QWEB_OPCODES, compile(namespace_expr, '<>', 'eval'), expr)
return namespace_expr
def _compile_expr(self, expr):
""" Compiles a purported Python expression to ast, verifies that it's safe
(according to safe_eval's semantics) and alter its variable references to
access values data instead
"""
# string must be stripped otherwise whitespace before the start for
# formatting purpose are going to break parse/compile
st = ast.parse(expr.strip(), mode='eval')
assert_valid_codeobj(
_SAFE_OPCODES,
compile(st, '<>',
'eval'), # could be expr, but eval *should* be fine
expr)
# ast.Expression().body -> expr
return Contextifier(_BUILTINS).visit(st).body
def _compile_expr(self, expr):
""" Compiles a purported Python expression to ast, verifies that it's safe
(according to safe_eval's semantics) and alter its variable references to
access values data instead
"""
# string must be stripped otherwise whitespace before the start for
# formatting purpose are going to break parse/compile
st = ast.parse(expr.strip(), mode='eval')
assert_valid_codeobj(
_SAFE_OPCODES,
compile(st, '<>', 'eval'), # could be expr, but eval *should* be fine
expr
)
# ast.Expression().body -> expr
return Contextifier(_BUILTINS).visit(st).body
def _compile_expr(self, expr, raise_on_missing=False):
""" Compiles a purported Python expression to compiled code, verifies
that it's safe (according to safe_eval's semantics) and alter its
variable references to access values data instead
:param expr: string
"""
readable = io.BytesIO(expr.strip().encode('utf-8'))
try:
tokens = list(tokenize.tokenize(readable.readline))
except tokenize.TokenError:
raise ValueError(f"Cannot compile expression: {expr}")
namespace_expr = self._compile_expr_tokens(tokens, self._allowed_keyword + list(self._available_objects.keys()), raise_on_missing=raise_on_missing)
assert_valid_codeobj(_SAFE_QWEB_OPCODES, compile(namespace_expr, '<>', 'eval'), expr)
return namespace_expr
