def to_bytes32(expr, args, kwargs, context):
in_arg = args[0]
input_type, _len = get_type(in_arg)
if input_type == "Bytes":
if _len > 32:
raise TypeMismatch(
f"Unable to convert bytes[{_len}] to bytes32, max length is too "
"large.")
with in_arg.cache_when_complex("bytes") as (b1, in_arg):
op = load_op(in_arg.location)
ofst = wordsize(in_arg.location) * DYNAMIC_ARRAY_OVERHEAD
bytes_val = [op, ["add", in_arg, ofst]]
# zero out any dirty bytes (which can happen in the last
# word of a bytearray)
len_ = get_bytearray_length(in_arg)
num_zero_bits = LLLnode.from_list(["mul", ["sub", 32, len_], 8])
with num_zero_bits.cache_when_complex("bits") as (b2,
num_zero_bits):
ret = shl(num_zero_bits, shr(num_zero_bits, bytes_val))
ret = b1.resolve(b2.resolve(ret))
else:
# literal
ret = in_arg
return LLLnode.from_list(ret, typ="bytes32", pos=getpos(expr))
def to_bytes_m(expr, arg, out_typ):
out_info = out_typ._bytes_info
_check_bytes(expr, arg, out_typ, max_bytes_allowed=out_info.m)
if isinstance(arg.typ, ByteArrayType):
bytes_val = LOAD(bytes_data_ptr(arg))
# zero out any dirty bytes (which can happen in the last
# word of a bytearray)
len_ = get_bytearray_length(arg)
num_zero_bits = IRnode.from_list(["mul", ["sub", 32, len_], 8])
with num_zero_bits.cache_when_complex("bits") as (b, num_zero_bits):
arg = shl(num_zero_bits, shr(num_zero_bits, bytes_val))
arg = b.resolve(arg)
elif is_bytes_m_type(arg.typ):
arg_info = arg.typ._bytes_info
# clamp if it's a downcast
if arg_info.m > out_info.m:
arg = bytes_clamp(arg, out_info.m)
elif is_integer_type(arg.typ) or is_base_type(arg.typ, "address"):
int_bits = arg.typ._int_info.bits
if out_info.m_bits < int_bits:
# question: allow with runtime clamp?
# arg = int_clamp(m_bits, signed=int_info.signed)
_FAIL(arg.typ, out_typ, expr)
# note: neg numbers not OOB. keep sign bit
arg = shl(256 - out_info.m_bits, arg)
elif is_decimal_type(arg.typ):
if out_info.m_bits < arg.typ._decimal_info.bits:
_FAIL(arg.typ, out_typ, expr)
# note: neg numbers not OOB. keep sign bit
arg = shl(256 - out_info.m_bits, arg)
else:
# bool
arg = shl(256 - out_info.m_bits, arg)
return IRnode.from_list(arg, typ=out_typ)
def _bytes_to_num(arg, out_typ, signed):
# converting a bytestring to a number:
# bytestring and bytes_m are right-padded with zeroes, int is left-padded.
# convert by shr or sar the number of zero bytes (converted to bits)
# e.g. "abcd000000000000" -> bitcast(000000000000abcd, output_type)
if isinstance(arg.typ, ByteArrayLike):
_len = get_bytearray_length(arg)
arg = LOAD(bytes_data_ptr(arg))
num_zero_bits = ["mul", 8, ["sub", 32, _len]]
elif is_bytes_m_type(arg.typ):
info = arg.typ._bytes_info
num_zero_bits = 8 * (32 - info.m)
else:
raise CompilerPanic("unreachable") # pragma: notest
if signed:
ret = sar(num_zero_bits, arg)
else:
ret = shr(num_zero_bits, arg)
annotation = (f"__intrinsic__byte_array_to_num({out_typ})", )
return IRnode.from_list(ret, annotation=annotation)
def byte_array_to_num(arg, out_type):
"""
Takes a <32 byte array as input, and outputs a number.
"""
# the location of the bytestring
bs_start = (LLLnode.from_list(
"bs_start", typ=arg.typ, location=arg.location, encoding=arg.encoding)
if arg.is_complex_lll else arg)
if arg.location == "storage":
len_ = get_bytearray_length(bs_start)
data = LLLnode.from_list(["sload", add_ofst(bs_start, 1)],
typ=BaseType("int256"))
else:
op = load_op(arg.location)
len_ = LLLnode.from_list([op, bs_start], typ=BaseType("int256"))
data = LLLnode.from_list([op, add_ofst(bs_start, 32)],
typ=BaseType("int256"))
# converting a bytestring to a number:
# bytestring is right-padded with zeroes, int is left-padded.
# convert by shr the number of zero bytes (converted to bits)
# e.g. "abcd000000000000" -> bitcast(000000000000abcd, output_type)
num_zero_bits = ["mul", 8, ["sub", 32, "len_"]]
bitcasted = LLLnode.from_list(shr(num_zero_bits, "val"), typ=out_type)
result = clamp_basetype(bitcasted)
# TODO use cache_when_complex for these `with` values
ret = ["with", "val", data, ["with", "len_", len_, result]]
if arg.is_complex_lll:
ret = ["with", "bs_start", arg, ret]
return LLLnode.from_list(
ret,
typ=BaseType(out_type),
annotation=f"__intrinsic__byte_array_to_num({out_type})",
)
def parse_regular_functions(regular_functions, sigs, external_interfaces,
global_ctx, default_function, init_function):
# check for payable/nonpayable external functions to optimize nonpayable assertions
func_types = [i._metadata["type"] for i in global_ctx._defs]
mutabilities = [
i.mutability for i in func_types
if i.visibility == FunctionVisibility.EXTERNAL
]
has_payable = any(i == StateMutability.PAYABLE for i in mutabilities)
has_nonpayable = any(i != StateMutability.PAYABLE for i in mutabilities)
is_default_payable = (default_function is not None
and default_function._metadata["type"].mutability
== StateMutability.PAYABLE)
# TODO streamline the nonpayable check logic
# when a contract has a payable default function and at least one nonpayable
# external function, we must perform the nonpayable check on every function
check_per_function = is_default_payable and has_nonpayable
# generate IR for regular functions
payable_funcs = []
nonpayable_funcs = []
internal_funcs = []
add_gas = 0
for func_node in regular_functions:
func_type = func_node._metadata["type"]
func_ir, frame_start, frame_size = generate_ir_for_function(
func_node, {
**{
"self": sigs
},
**external_interfaces
}, global_ctx, check_per_function)
if func_type.visibility == FunctionVisibility.INTERNAL:
internal_funcs.append(func_ir)
elif func_type.mutability == StateMutability.PAYABLE:
add_gas += 30 # CMC 20210910 why?
payable_funcs.append(func_ir)
else:
add_gas += 30 # CMC 20210910 why?
nonpayable_funcs.append(func_ir)
func_ir.total_gas += add_gas
# update sigs with metadata gathered from compiling the function so that
# we can handle calls to self
# TODO we only need to do this for internal functions; external functions
# cannot be called via `self`
sig = FunctionSignature.from_definition(func_node, external_interfaces,
global_ctx._structs)
sig.gas = func_ir.total_gas
sig.frame_start = frame_start
sig.frame_size = frame_size
sigs[sig.name] = sig
# generate IR for fallback function
if default_function:
fallback_ir, _frame_start, _frame_size = generate_ir_for_function(
default_function,
{
**{
"self": sigs
},
**external_interfaces
},
global_ctx,
# include a nonpayble check here if the contract only has a default function
check_per_function or not regular_functions,
)
else:
fallback_ir = IRnode.from_list(["revert", 0, 0],
typ=None,
annotation="Default function")
if check_per_function:
external_seq = ["seq"] + payable_funcs + nonpayable_funcs
else:
# payable functions are placed prior to nonpayable functions
# and seperated by a nonpayable assertion
external_seq = ["seq"]
if has_payable:
external_seq += payable_funcs
if has_nonpayable:
external_seq.append(["assert", ["iszero", "callvalue"]])
external_seq += nonpayable_funcs
# ensure the external jumptable section gets closed out
# (for basic block hygiene and also for zksync interpreter)
# NOTE: this jump gets optimized out in assembly since the
# fallback label is the immediate next instruction,
close_selector_section = ["goto", "fallback"]
# bytecode is organized by: external functions, fallback fn, internal functions
# this way we save gas and reduce bytecode by not jumping over internal functions
runtime = [
"seq",
# check that calldatasize is at least 4, otherwise
# calldataload will load zeros (cf. yellow paper).
["if", ["lt", "calldatasize", 4], ["goto", "fallback"]],
[
"with", "_calldata_method_id",
shr(224, ["calldataload", 0]), external_seq
],
close_selector_section,
["label", "fallback", ["var_list"], fallback_ir],
]
runtime.extend(internal_funcs)
return runtime
def _runtime_ir(runtime_functions, all_sigs, global_ctx):
# categorize the runtime functions because we will organize the runtime
# code into the following sections:
# payable functions, nonpayable functions, fallback function, internal_functions
internal_functions = [f for f in runtime_functions if _is_internal(f)]
external_functions = [f for f in runtime_functions if not _is_internal(f)]
default_function = next(
(f for f in external_functions if _is_default_func(f)), None)
# functions that need to go exposed in the selector section
regular_functions = [
f for f in external_functions if not _is_default_func(f)
]
payables = [f for f in regular_functions if _is_payable(f)]
nonpayables = [f for f in regular_functions if not _is_payable(f)]
# create a map of the IR functions since they might live in both
# runtime and deploy code (if init function calls them)
internal_functions_map: Dict[str, IRnode] = {}
for func_ast in internal_functions:
func_ir = generate_ir_for_function(func_ast, all_sigs, global_ctx,
False)
internal_functions_map[func_ast.name] = func_ir
# for some reason, somebody may want to deploy a contract with no
# external functions, or more likely, a "pure data" contract which
# contains immutables
if len(external_functions) == 0:
# TODO: prune internal functions in this case?
runtime = ["seq"] + list(internal_functions_map.values())
return runtime, internal_functions_map
# note: if the user does not provide one, the default fallback function
# reverts anyway. so it does not hurt to batch the payable check.
default_is_nonpayable = default_function is None or not _is_payable(
default_function)
# when a contract has a nonpayable default function,
# we can do a single check for all nonpayable functions
batch_payable_check = len(nonpayables) > 0 and default_is_nonpayable
skip_nonpayable_check = batch_payable_check
selector_section = ["seq"]
for func_ast in payables:
func_ir = generate_ir_for_function(func_ast, all_sigs, global_ctx,
False)
selector_section.append(func_ir)
if batch_payable_check:
selector_section.append(["assert", ["iszero", "callvalue"]])
for func_ast in nonpayables:
func_ir = generate_ir_for_function(func_ast, all_sigs, global_ctx,
skip_nonpayable_check)
selector_section.append(func_ir)
if default_function:
fallback_ir = generate_ir_for_function(default_function, all_sigs,
global_ctx,
skip_nonpayable_check)
else:
fallback_ir = IRnode.from_list(["revert", 0, 0],
annotation="Default function")
# ensure the external jumptable section gets closed out
# (for basic block hygiene and also for zksync interpreter)
# NOTE: this jump gets optimized out in assembly since the
# fallback label is the immediate next instruction,
close_selector_section = ["goto", "fallback"]
runtime = [
"seq",
# check that calldatasize is at least 4, otherwise
# calldataload will load zeros (cf. yellow paper).
["if", ["lt", "calldatasize", 4], ["goto", "fallback"]],
[
"with", "_calldata_method_id",
shr(224, ["calldataload", 0]), selector_section
],
close_selector_section,
["label", "fallback", ["var_list"], fallback_ir],
]
# TODO: prune unreachable functions?
runtime.extend(internal_functions_map.values())
return runtime, internal_functions_map
