def make_return_stmt(stmt,
context,
begin_pos,
_size,
loop_memory_position=None):
from vyper.parser.function_definitions.utils import get_nonreentrant_lock
_, nonreentrant_post = get_nonreentrant_lock(context.sig,
context.global_ctx)
if context.is_private:
if loop_memory_position is None:
loop_memory_position = context.new_placeholder(
typ=BaseType("uint256"))
# Make label for stack push loop.
label_id = "_".join([
str(x) for x in (context.method_id, stmt.lineno, stmt.col_offset)
])
exit_label = f"make_return_loop_exit_{label_id}"
start_label = f"make_return_loop_start_{label_id}"
# Push prepared data onto the stack,
# in reverse order so it can be popped of in order.
if isinstance(begin_pos, int) and isinstance(_size, int):
# static values, unroll the mloads instead.
mloads = [["mload", pos] for pos in range(begin_pos, _size, 32)]
return (["seq_unchecked"] + mloads + nonreentrant_post +
[["jump", ["mload", context.callback_ptr]]])
else:
mloads = [
"seq_unchecked",
["mstore", loop_memory_position, _size],
["label", start_label],
[ # maybe exit loop / break.
"if",
["le", ["mload", loop_memory_position], 0],
["goto", exit_label],
],
[ # push onto stack
"mload",
[
"add", begin_pos,
["sub", ["mload", loop_memory_position], 32]
],
],
[ # decrement i by 32.
"mstore",
loop_memory_position,
["sub", ["mload", loop_memory_position], 32],
],
["goto", start_label],
["label", exit_label],
]
return (["seq_unchecked"] + [mloads] + nonreentrant_post +
[["jump", ["mload", context.callback_ptr]]])
else:
return ["seq_unchecked"
] + nonreentrant_post + [["return", begin_pos, _size]]
def make_return_stmt(stmt,
context,
begin_pos,
_size,
loop_memory_position=None):
from vyper.parser.function_definitions.utils import (get_nonreentrant_lock)
_, nonreentrant_post = get_nonreentrant_lock(context.sig,
context.global_ctx)
if context.is_private:
if loop_memory_position is None:
loop_memory_position = context.new_placeholder(
typ=BaseType('uint256'))
# Make label for stack push loop.
label_id = '_'.join([
str(x) for x in (context.method_id, stmt.lineno, stmt.col_offset)
])
exit_label = 'make_return_loop_exit_%s' % label_id
start_label = 'make_return_loop_start_%s' % label_id
# Push prepared data onto the stack,
# in reverse order so it can be popped of in order.
if isinstance(begin_pos, int) and isinstance(_size, int):
# static values, unroll the mloads instead.
mloads = [['mload', pos] for pos in range(begin_pos, _size, 32)]
return ['seq_unchecked'] + mloads + nonreentrant_post + \
[['jump', ['mload', context.callback_ptr]]]
else:
mloads = [
'seq_unchecked',
['mstore', loop_memory_position, _size],
['label', start_label],
[ # maybe exit loop / break.
'if', ['le', ['mload', loop_memory_position], 0],
['goto', exit_label]
],
[ # push onto stack
'mload',
[
'add', begin_pos,
['sub', ['mload', loop_memory_position], 32]
]
],
[ # decrement i by 32.
'mstore',
loop_memory_position,
['sub', ['mload', loop_memory_position], 32],
],
['goto', start_label],
['label', exit_label]
]
return ['seq_unchecked'] + [mloads] + nonreentrant_post + \
[['jump', ['mload', context.callback_ptr]]]
else:
return ['seq_unchecked'
] + nonreentrant_post + [['return', begin_pos, _size]]
def make_return_stmt(stmt, context, begin_pos, _size, loop_memory_position=None):
from vyper.parser.function_definitions.utils import get_nonreentrant_lock
func_type = stmt.get_ancestor(vy_ast.FunctionDef)._metadata["type"]
_, nonreentrant_post = get_nonreentrant_lock(func_type, context.global_ctx)
if context.is_internal:
if loop_memory_position is None:
loop_memory_position = context.new_internal_variable(BaseType("uint256"))
# Make label for stack push loop.
label_id = "_".join([str(x) for x in (context.method_id, stmt.lineno, stmt.col_offset)])
exit_label = f"make_return_loop_exit_{label_id}"
start_label = f"make_return_loop_start_{label_id}"
# Push prepared data onto the stack,
# in reverse order so it can be popped of in order.
if isinstance(begin_pos, int) and isinstance(_size, int):
# static values, unroll the mloads instead.
mloads = [["mload", pos] for pos in range(begin_pos, _size, 32)]
else:
mloads = [
"seq_unchecked",
["mstore", loop_memory_position, _size],
["label", start_label],
[ # maybe exit loop / break.
"if",
["le", ["mload", loop_memory_position], 0],
["goto", exit_label],
],
[ # push onto stack
"mload",
["add", begin_pos, ["sub", ["mload", loop_memory_position], 32]],
],
[ # decrement i by 32.
"mstore",
loop_memory_position,
["sub", ["mload", loop_memory_position], 32],
],
["goto", start_label],
["label", exit_label],
]
# if we are in a for loop, we have to exit prior to returning
exit_repeater = ["exit_repeater"] if context.forvars else []
return (
["seq_unchecked"]
+ exit_repeater
+ mloads
+ nonreentrant_post
+ [["jump", ["mload", context.callback_ptr]]]
)
else:
return ["seq_unchecked"] + nonreentrant_post + [["return", begin_pos, _size]]
def parse_private_function(code: ast.FunctionDef, sig: FunctionSignature,
context: Context) -> LLLnode:
"""
Parse a private function (FuncDef), and produce full function body.
:param sig: the FuntionSignature
:param code: ast of function
:return: full sig compare & function body
"""
validate_private_function(code, sig)
# Get nonreentrant lock
nonreentrant_pre, nonreentrant_post = get_nonreentrant_lock(
sig, context.global_ctx)
# Create callback_ptr, this stores a destination in the bytecode for a private
# function to jump to after a function has executed.
clampers: List[LLLnode] = []
# Allocate variable space.
context.memory_allocator.increase_memory(sig.max_copy_size)
_post_callback_ptr = f"{sig.name}_{sig.method_id}_post_callback_ptr"
context.callback_ptr = context.new_placeholder(typ=BaseType('uint256'))
clampers.append(
LLLnode.from_list(
['mstore', context.callback_ptr, 'pass'],
annotation='pop callback pointer',
))
if sig.total_default_args > 0:
clampers.append(LLLnode.from_list(['label', _post_callback_ptr]))
# private functions without return types need to jump back to
# the calling function, as there is no return statement to handle the
# jump.
if sig.output_type is None:
stop_func = [['jump', ['mload', context.callback_ptr]]]
else:
stop_func = [['stop']]
# Generate copiers
if len(sig.base_args) == 0:
copier = ['pass']
clampers.append(LLLnode.from_list(copier))
elif sig.total_default_args == 0:
copier = get_private_arg_copier(
total_size=sig.base_copy_size,
memory_dest=MemoryPositions.RESERVED_MEMORY)
clampers.append(LLLnode.from_list(copier))
# Fill variable positions
for arg in sig.args:
if isinstance(arg.typ, ByteArrayLike):
mem_pos, _ = context.memory_allocator.increase_memory(
32 * get_size_of_type(arg.typ))
context.vars[arg.name] = VariableRecord(arg.name, mem_pos, arg.typ,
False)
else:
context.vars[arg.name] = VariableRecord(
arg.name,
MemoryPositions.RESERVED_MEMORY + arg.pos,
arg.typ,
False,
)
# Private function copiers. No clamping for private functions.
dyn_variable_names = [
a.name for a in sig.base_args if isinstance(a.typ, ByteArrayLike)
]
if dyn_variable_names:
i_placeholder = context.new_placeholder(typ=BaseType('uint256'))
unpackers: List[Any] = []
for idx, var_name in enumerate(dyn_variable_names):
var = context.vars[var_name]
ident = f"_load_args_{sig.method_id}_dynarg{idx}"
o = make_unpacker(ident=ident,
i_placeholder=i_placeholder,
begin_pos=var.pos)
unpackers.append(o)
if not unpackers:
unpackers = ['pass']
# 0 added to complete full overarching 'seq' statement, see private_label.
unpackers.append(0)
clampers.append(
LLLnode.from_list(
['seq_unchecked'] + unpackers,
typ=None,
annotation='dynamic unpacker',
pos=getpos(code),
))
# Function has default arguments.
if sig.total_default_args > 0: # Function with default parameters.
default_sigs = sig_utils.generate_default_arg_sigs(
code, context.sigs, context.global_ctx)
sig_chain: List[Any] = ['seq']
for default_sig in default_sigs:
sig_compare, private_label = get_sig_statements(
default_sig, getpos(code))
# Populate unset default variables
set_defaults = []
for arg_name in get_default_names_to_set(sig, default_sig):
value = Expr(sig.default_values[arg_name], context).lll_node
var = context.vars[arg_name]
left = LLLnode.from_list(var.pos,
typ=var.typ,
location='memory',
pos=getpos(code),
mutable=var.mutable)
set_defaults.append(
make_setter(left, value, 'memory', pos=getpos(code)))
current_sig_arg_names = [x.name for x in default_sig.args]
# Load all variables in default section, if private,
# because the stack is a linear pipe.
copier_arg_count = len(default_sig.args)
copier_arg_names = current_sig_arg_names
# Order copier_arg_names, this is very important.
copier_arg_names = [
x.name for x in default_sig.args if x.name in copier_arg_names
]
# Variables to be populated from calldata/stack.
default_copiers: List[Any] = []
if copier_arg_count > 0:
# Get map of variables in calldata, with thier offsets
offset = 4
calldata_offset_map = {}
for arg in default_sig.args:
calldata_offset_map[arg.name] = offset
offset += (32 if isinstance(arg.typ, ByteArrayLike) else
get_size_of_type(arg.typ) * 32)
# Copy set default parameters from calldata
dynamics = []
for arg_name in copier_arg_names:
var = context.vars[arg_name]
if isinstance(var.typ, ByteArrayLike):
_size = 32
dynamics.append(var.pos)
else:
_size = var.size * 32
default_copiers.append(
get_private_arg_copier(
memory_dest=var.pos,
total_size=_size,
))
# Unpack byte array if necessary.
if dynamics:
i_placeholder = context.new_placeholder(
typ=BaseType('uint256'))
for idx, var_pos in enumerate(dynamics):
ident = f'unpack_default_sig_dyn_{default_sig.method_id}_arg{idx}'
default_copiers.append(
make_unpacker(
ident=ident,
i_placeholder=i_placeholder,
begin_pos=var_pos,
))
default_copiers.append(0) # for over arching seq, POP
sig_chain.append([
'if', sig_compare,
[
'seq', private_label,
LLLnode.from_list([
'mstore',
context.callback_ptr,
'pass',
],
annotation='pop callback pointer',
pos=getpos(code)),
['seq'] + set_defaults if set_defaults else ['pass'],
['seq_unchecked'] +
default_copiers if default_copiers else ['pass'],
['goto', _post_callback_ptr]
]
])
# With private functions all variable loading occurs in the default
# function sub routine.
_clampers = [['label', _post_callback_ptr]]
# Function with default parameters.
o = LLLnode.from_list(
[
'seq',
sig_chain,
[
'if',
0, # can only be jumped into
[
'seq', ['seq'] + nonreentrant_pre + _clampers +
[parse_body(c, context)
for c in code.body] + nonreentrant_post + stop_func
],
],
],
typ=None,
pos=getpos(code))
else:
# Function without default parameters.
sig_compare, private_label = get_sig_statements(sig, getpos(code))
o = LLLnode.from_list([
'if', sig_compare, ['seq'] + [private_label] + nonreentrant_pre +
clampers + [parse_body(c, context)
for c in code.body] + nonreentrant_post + stop_func
],
typ=None,
pos=getpos(code))
return o
return o
def parse_external_function(
code: vy_ast.FunctionDef,
sig: FunctionSignature,
context: Context,
check_nonpayable: bool,
) -> LLLnode:
"""
Parse a external function (FuncDef), and produce full function body.
:param sig: the FuntionSignature
:param code: ast of function
:param check_nonpayable: if True, include a check that `msg.value == 0`
at the beginning of the function
:return: full sig compare & function body
"""
func_type = code._metadata["type"]
# Get nonreentrant lock
nonreentrant_pre, nonreentrant_post = get_nonreentrant_lock(
func_type, context.global_ctx)
clampers = []
# Generate copiers
copier: List[Any] = ["pass"]
if not len(sig.base_args):
copier = ["pass"]
elif sig.name == "__init__":
copier = [
"codecopy", MemoryPositions.RESERVED_MEMORY, "~codelen",
sig.base_copy_size
]
context.memory_allocator.expand_memory(sig.max_copy_size)
clampers.append(copier)
if check_nonpayable and sig.mutability != "payable":
# if the contract contains payable functions, but this is not one of them
# add an assertion that the value of the call is zero
clampers.append(["assert", ["iszero", "callvalue"]])
# Fill variable positions
default_args_start_pos = len(sig.base_args)
for i, arg in enumerate(sig.args):
if i < len(sig.base_args):
clampers.append(
make_arg_clamper(
arg.pos,
context.memory_allocator.get_next_memory_position(),
arg.typ,
sig.name == "__init__",
))
if isinstance(arg.typ, ByteArrayLike):
mem_pos = context.memory_allocator.expand_memory(
32 * get_size_of_type(arg.typ))
context.vars[arg.name] = VariableRecord(arg.name, mem_pos, arg.typ,
False)
else:
if sig.name == "__init__":
context.vars[arg.name] = VariableRecord(
arg.name,
MemoryPositions.RESERVED_MEMORY + arg.pos,
arg.typ,
False,
)
elif i >= default_args_start_pos: # default args need to be allocated in memory.
type_size = get_size_of_type(arg.typ) * 32
default_arg_pos = context.memory_allocator.expand_memory(
type_size)
context.vars[arg.name] = VariableRecord(
name=arg.name,
pos=default_arg_pos,
typ=arg.typ,
mutable=False,
)
else:
context.vars[arg.name] = VariableRecord(name=arg.name,
pos=4 + arg.pos,
typ=arg.typ,
mutable=False,
location="calldata")
# Create "clampers" (input well-formedness checkers)
# Return function body
if sig.name == "__init__":
o = LLLnode.from_list(
["seq"] + clampers +
[parse_body(code.body, context)], # type: ignore
pos=getpos(code),
)
# Is default function.
elif sig.is_default_func():
o = LLLnode.from_list(
["seq"] + clampers + [parse_body(code.body, context)] +
[["stop"]], # type: ignore
pos=getpos(code),
)
# Is a normal function.
else:
# Function with default parameters.
if sig.total_default_args > 0:
function_routine = f"{sig.name}_{sig.method_id}"
default_sigs = sig_utils.generate_default_arg_sigs(
code, context.sigs, context.global_ctx)
sig_chain: List[Any] = ["seq"]
for default_sig in default_sigs:
sig_compare, _ = get_sig_statements(default_sig, getpos(code))
# Populate unset default variables
set_defaults = []
for arg_name in get_default_names_to_set(sig, default_sig):
value = Expr(sig.default_values[arg_name],
context).lll_node
var = context.vars[arg_name]
left = LLLnode.from_list(
var.pos,
typ=var.typ,
location="memory",
pos=getpos(code),
mutable=var.mutable,
)
set_defaults.append(
make_setter(left, value, "memory", pos=getpos(code)))
current_sig_arg_names = {x.name for x in default_sig.args}
base_arg_names = {arg.name for arg in sig.base_args}
copier_arg_count = len(default_sig.args) - len(sig.base_args)
copier_arg_names = list(current_sig_arg_names - base_arg_names)
# Order copier_arg_names, this is very important.
copier_arg_names = [
x.name for x in default_sig.args
if x.name in copier_arg_names
]
# Variables to be populated from calldata/stack.
default_copiers: List[Any] = []
if copier_arg_count > 0:
# Get map of variables in calldata, with thier offsets
offset = 4
calldata_offset_map = {}
for arg in default_sig.args:
calldata_offset_map[arg.name] = offset
offset += (32 if isinstance(arg.typ, ByteArrayLike)
else get_size_of_type(arg.typ) * 32)
# Copy default parameters from calldata.
for arg_name in copier_arg_names:
var = context.vars[arg_name]
calldata_offset = calldata_offset_map[arg_name]
# Add clampers.
default_copiers.append(
make_arg_clamper(
calldata_offset - 4,
var.pos,
var.typ,
))
# Add copying code.
_offset: Union[int, List[Any]] = calldata_offset
if isinstance(var.typ, ByteArrayLike):
_offset = [
"add", 4, ["calldataload", calldata_offset]
]
default_copiers.append(
get_external_arg_copier(
memory_dest=var.pos,
total_size=var.size * 32,
offset=_offset,
))
default_copiers.append(0) # for over arching seq, POP
sig_chain.append([
"if",
sig_compare,
[
"seq",
["seq"] + set_defaults if set_defaults else ["pass"],
["seq_unchecked"] +
default_copiers if default_copiers else ["pass"],
["goto", function_routine],
],
])
# Function with default parameters.
function_jump_label = f"{sig.name}_{sig.method_id}_skip"
o = LLLnode.from_list(
[
"seq",
sig_chain,
[
"seq",
["goto", function_jump_label],
["label", function_routine],
["seq"] + nonreentrant_pre + clampers +
[parse_body(c, context)
for c in code.body] + nonreentrant_post + [["stop"]],
["label", function_jump_label],
],
],
typ=None,
pos=getpos(code),
)
else:
# Function without default parameters.
sig_compare, _ = get_sig_statements(sig, getpos(code))
o = LLLnode.from_list(
[
"if",
sig_compare,
["seq"] + nonreentrant_pre + clampers +
[parse_body(c, context)
for c in code.body] + nonreentrant_post + [["stop"]],
],
typ=None,
pos=getpos(code),
)
return o
def parse_public_function(code: ast.FunctionDef, sig: FunctionSignature,
context: Context) -> LLLnode:
"""
Parse a public function (FuncDef), and produce full function body.
:param sig: the FuntionSignature
:param code: ast of function
:return: full sig compare & function body
"""
validate_public_function(code, sig, context.global_ctx)
# Get nonreentrant lock
nonreentrant_pre, nonreentrant_post = get_nonreentrant_lock(
sig, context.global_ctx)
clampers = []
# Generate copiers
copier: List[Any] = ['pass']
if not len(sig.base_args):
copier = ['pass']
elif sig.name == '__init__':
copier = [
'codecopy', MemoryPositions.RESERVED_MEMORY, '~codelen',
sig.base_copy_size
]
context.memory_allocator.increase_memory(sig.max_copy_size)
clampers.append(copier)
# Add asserts for payable and internal
if not sig.payable:
clampers.append(['assert', ['iszero', 'callvalue']])
# Fill variable positions
default_args_start_pos = len(sig.base_args)
for i, arg in enumerate(sig.args):
if i < len(sig.base_args):
clampers.append(
make_arg_clamper(
arg.pos,
context.memory_allocator.get_next_memory_position(),
arg.typ,
sig.name == '__init__',
))
if isinstance(arg.typ, ByteArrayLike):
mem_pos, _ = context.memory_allocator.increase_memory(
32 * get_size_of_type(arg.typ))
context.vars[arg.name] = VariableRecord(arg.name, mem_pos, arg.typ,
False)
else:
if sig.name == '__init__':
context.vars[arg.name] = VariableRecord(
arg.name,
MemoryPositions.RESERVED_MEMORY + arg.pos,
arg.typ,
False,
)
elif i >= default_args_start_pos: # default args need to be allocated in memory.
default_arg_pos, _ = context.memory_allocator.increase_memory(
32)
context.vars[arg.name] = VariableRecord(
name=arg.name,
pos=default_arg_pos,
typ=arg.typ,
mutable=False,
)
else:
context.vars[arg.name] = VariableRecord(name=arg.name,
pos=4 + arg.pos,
typ=arg.typ,
mutable=False,
location='calldata')
# Create "clampers" (input well-formedness checkers)
# Return function body
if sig.name == '__init__':
o = LLLnode.from_list(
['seq'] + clampers +
[parse_body(code.body, context)], # type: ignore
pos=getpos(code),
)
# Is default function.
elif sig.is_default_func():
if len(sig.args) > 0:
raise FunctionDeclarationException(
'Default function may not receive any arguments.', code)
o = LLLnode.from_list(
['seq'] + clampers +
[parse_body(code.body, context)], # type: ignore
pos=getpos(code),
)
# Is a normal function.
else:
# Function with default parameters.
if sig.total_default_args > 0:
function_routine = f"{sig.name}_{sig.method_id}"
default_sigs = sig_utils.generate_default_arg_sigs(
code, context.sigs, context.global_ctx)
sig_chain: List[Any] = ['seq']
for default_sig in default_sigs:
sig_compare, _ = get_sig_statements(default_sig, getpos(code))
# Populate unset default variables
set_defaults = []
for arg_name in get_default_names_to_set(sig, default_sig):
value = Expr(sig.default_values[arg_name],
context).lll_node
var = context.vars[arg_name]
left = LLLnode.from_list(var.pos,
typ=var.typ,
location='memory',
pos=getpos(code),
mutable=var.mutable)
set_defaults.append(
make_setter(left, value, 'memory', pos=getpos(code)))
current_sig_arg_names = {x.name for x in default_sig.args}
base_arg_names = {arg.name for arg in sig.base_args}
copier_arg_count = len(default_sig.args) - len(sig.base_args)
copier_arg_names = list(current_sig_arg_names - base_arg_names)
# Order copier_arg_names, this is very important.
copier_arg_names = [
x.name for x in default_sig.args
if x.name in copier_arg_names
]
# Variables to be populated from calldata/stack.
default_copiers: List[Any] = []
if copier_arg_count > 0:
# Get map of variables in calldata, with thier offsets
offset = 4
calldata_offset_map = {}
for arg in default_sig.args:
calldata_offset_map[arg.name] = offset
offset += (32 if isinstance(arg.typ, ByteArrayLike)
else get_size_of_type(arg.typ) * 32)
# Copy default parameters from calldata.
for arg_name in copier_arg_names:
var = context.vars[arg_name]
calldata_offset = calldata_offset_map[arg_name]
# Add clampers.
default_copiers.append(
make_arg_clamper(
calldata_offset - 4,
var.pos,
var.typ,
))
# Add copying code.
_offset: Union[int, List[Any]] = calldata_offset
if isinstance(var.typ, ByteArrayLike):
_offset = [
'add', 4, ['calldataload', calldata_offset]
]
default_copiers.append(
get_public_arg_copier(
memory_dest=var.pos,
total_size=var.size * 32,
offset=_offset,
))
default_copiers.append(0) # for over arching seq, POP
sig_chain.append([
'if', sig_compare,
[
'seq',
['seq'] + set_defaults if set_defaults else ['pass'],
['seq_unchecked'] +
default_copiers if default_copiers else ['pass'],
['goto', function_routine]
]
])
# Function with default parameters.
o = LLLnode.from_list(
[
'seq',
sig_chain,
[
'if',
0, # can only be jumped into
[
'seq', ['label', function_routine
], ['seq'] + nonreentrant_pre + clampers +
[parse_body(c, context) for c in code.body] +
nonreentrant_post + [['stop']]
],
],
],
typ=None,
pos=getpos(code))
else:
# Function without default parameters.
sig_compare, _ = get_sig_statements(sig, getpos(code))
o = LLLnode.from_list([
'if', sig_compare, ['seq'] + nonreentrant_pre + clampers +
[parse_body(c, context)
for c in code.body] + nonreentrant_post + [['stop']]
],
typ=None,
pos=getpos(code))
return o
