def abi_decode(lll_node, src, pos=None):
os = o_list(lll_node, pos=pos)
lll_ret = ["seq"]
parent_abi_t = abi_type_of(lll_node.typ)
for i, o in enumerate(os):
abi_t = abi_type_of(o.typ)
src_loc = LLLnode("src_loc", typ=o.typ, location=src.location)
if parent_abi_t.is_tuple():
if abi_t.is_dynamic():
child_loc = ["add", "src", unwrap_location(src_loc)]
child_loc = LLLnode.from_list(child_loc,
typ=o.typ,
location=src.location)
else:
child_loc = src_loc
# descend into the child tuple
lll_ret.append(abi_decode(o, child_loc, pos=pos))
else:
lll_ret.append(
make_setter(o, src_loc, location=o.location, pos=pos))
if i + 1 == len(os):
pass # optimize out the last pointer increment
else:
sz = abi_t.embedded_static_size()
lll_ret.append(["set", "src_loc", ["add", "src_loc", sz]])
lll_ret = ["with", "src", src, ["with", "src_loc", "src", lll_ret]]
return lll_ret
def pack_logging_data(arg_nodes, arg_types, context, pos):
# Checks to see if there's any data
if not arg_nodes:
return ["seq"], 0, None, 0
holder = ["seq"]
maxlen = len(arg_nodes) * 32 # total size of all packed args (upper limit)
# Unroll any function calls, to temp variables.
prealloacted = {}
for idx, node in enumerate(arg_nodes):
if isinstance(
node,
(vy_ast.Str, vy_ast.Call)) and node.get("func.id") != "empty":
expr = Expr(node, context)
source_lll = expr.lll_node
tmp_variable = context.new_internal_variable(source_lll.typ)
tmp_variable_node = LLLnode.from_list(
tmp_variable,
typ=source_lll.typ,
pos=getpos(node),
location="memory",
annotation=f"log_prealloacted {source_lll.typ}",
)
# Copy bytes.
holder.append(
make_setter(tmp_variable_node,
source_lll,
pos=getpos(node),
location="memory"))
prealloacted[idx] = tmp_variable_node
# Create internal variables for for dynamic and static args.
static_types = []
for typ in arg_types:
static_types.append(
typ if not typ.is_dynamic_size else Uint256Definition())
requires_dynamic_offset = any(typ.is_dynamic_size for typ in arg_types)
dynamic_offset_counter = None
if requires_dynamic_offset:
# TODO refactor out old type objects
dynamic_offset_counter = context.new_internal_variable(BaseType(32))
dynamic_placeholder = context.new_internal_variable(BaseType(32))
static_vars = [context.new_internal_variable(i) for i in static_types]
# Populate static placeholders.
for i, (node, typ) in enumerate(zip(arg_nodes, arg_types)):
placeholder = static_vars[i]
if not isinstance(typ, ArrayValueAbstractType):
holder, maxlen = pack_args_by_32(
holder,
maxlen,
prealloacted.get(i, node),
typ,
context,
placeholder,
pos=pos,
)
# Dynamic position starts right after the static args.
if requires_dynamic_offset:
holder.append(
LLLnode.from_list(["mstore", dynamic_offset_counter, maxlen]))
# Calculate maximum dynamic offset placeholders, used for gas estimation.
for typ in arg_types:
if typ.is_dynamic_size:
maxlen += typ.size_in_bytes
if requires_dynamic_offset:
datamem_start = dynamic_placeholder + 32
else:
datamem_start = static_vars[0]
# Copy necessary data into allocated dynamic section.
for i, (node, typ) in enumerate(zip(arg_nodes, arg_types)):
if isinstance(typ, ArrayValueAbstractType):
if isinstance(node,
vy_ast.Call) and node.func.get("id") == "empty":
# TODO add support for this
raise StructureException(
"Cannot use `empty` on Bytes or String types within an event log",
node)
pack_args_by_32(
holder=holder,
maxlen=maxlen,
arg=prealloacted.get(i, node),
typ=typ,
context=context,
placeholder=static_vars[i],
datamem_start=datamem_start,
dynamic_offset_counter=dynamic_offset_counter,
pos=pos,
)
return holder, maxlen, dynamic_offset_counter, datamem_start
def pack_logging_topics(event_id, arg_nodes, arg_types, context):
topics = [event_id]
for node, typ in zip(arg_nodes, arg_types):
value = Expr(node, context).lll_node
if isinstance(typ, ArrayValueAbstractType):
if isinstance(node, (vy_ast.Str, vy_ast.Bytes)):
# for literals, generate the topic at compile time
value = node.value
if isinstance(value, str):
value = value.encode()
topics.append(bytes_to_int(keccak256(value)))
elif value.location == "memory":
topics.append(["sha3", ["add", value, 32], ["mload", value]])
else:
# storage or calldata
placeholder = context.new_internal_variable(value.typ)
placeholder_node = LLLnode.from_list(placeholder,
typ=value.typ,
location="memory")
copier = make_byte_array_copier(
placeholder_node,
LLLnode.from_list("_sub",
typ=value.typ,
location=value.location),
)
lll_node = [
"with",
"_sub",
value,
[
"seq", copier,
[
"sha3", ["add", placeholder, 32],
["mload", placeholder]
]
],
]
topics.append(lll_node)
elif isinstance(typ, ArrayDefinition):
size = typ.size_in_bytes
if value.location == "memory":
topics.append(["sha3", value, size])
else:
# storage or calldata
placeholder = context.new_internal_variable(value.typ)
placeholder_node = LLLnode.from_list(placeholder,
typ=value.typ,
location="memory")
setter = make_setter(placeholder_node, value, "memory",
value.pos)
lll_node = ["seq", setter, ["sha3", placeholder, size]]
topics.append(lll_node)
else:
value = unwrap_location(value)
topics.append(value)
return topics
def parse_internal_function(code: vy_ast.FunctionDef, sig: FunctionSignature,
context: Context) -> LLLnode:
"""
Parse a internal function (FuncDef), and produce full function body.
:param sig: the FuntionSignature
:param code: ast of function
:return: full sig compare & function body
"""
func_type = code._metadata["type"]
# Get nonreentrant lock
nonreentrant_pre, nonreentrant_post = get_nonreentrant_lock(func_type)
# Create callback_ptr, this stores a destination in the bytecode for a internal
# function to jump to after a function has executed.
clampers: List[LLLnode] = []
# Allocate variable space.
context.memory_allocator.expand_memory(sig.max_copy_size)
_post_callback_ptr = f"{sig.name}_{sig.method_id}_post_callback_ptr"
context.callback_ptr = context.new_internal_variable(
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]))
# internal 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_internal_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.expand_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,
)
# internal function copiers. No clamping for internal 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_internal_variable(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 internal_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, internal_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 internal,
# 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_internal_arg_copier(
memory_dest=var.pos,
total_size=_size,
))
# Unpack byte array if necessary.
if dynamics:
i_placeholder = context.new_internal_variable(
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",
internal_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 internal functions all variable loading occurs in the default
# function sub routine.
_clampers = [["label", _post_callback_ptr]]
# Function with default parameters.
return LLLnode.from_list(
[
"seq",
sig_chain,
["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, internal_label = get_sig_statements(sig, getpos(code))
return LLLnode.from_list(
["seq"] + [internal_label] + nonreentrant_pre + clampers +
[parse_body(c, context)
for c in code.body] + nonreentrant_post + stop_func,
typ=None,
pos=getpos(code),
)
def check_assign(lhs, rhs, pos, in_function_call=False):
make_setter(lhs,
rhs,
location="memory",
pos=pos,
in_function_call=in_function_call)
def gen_tuple_return(stmt, context, sub):
abi_typ = abi_type_of(context.return_type)
# according to the ABI, return types are ALWAYS tuples even if
# only one element is being returned.
# https://solidity.readthedocs.io/en/latest/abi-spec.html#function-selector-and-argument-encoding
# "and the return values v_1, ..., v_k of f are encoded as
#
# enc((v_1, ..., v_k))
# i.e. the values are combined into a tuple and encoded.
# "
# therefore, wrap it in a tuple if it's not already a tuple.
# (big difference between returning `(bytes,)` and `bytes`.
abi_typ = ensure_tuple(abi_typ)
abi_bytes_needed = abi_typ.static_size() + abi_typ.dynamic_size_bound()
dst = context.memory_allocator.expand_memory(abi_bytes_needed)
return_buffer = LLLnode(dst,
location="memory",
annotation="return_buffer",
typ=context.return_type)
check_assign(return_buffer, sub, pos=getpos(stmt))
if sub.value == "multi":
if isinstance(context.return_type,
TupleType) and not abi_typ.dynamic_size_bound():
# for tuples where every value is of the same type and a fixed length,
# we can simplify the encoding by using make_setter, since
# our memory encoding happens to be identical to the ABI
# encoding.
new_sub = LLLnode.from_list(
context.new_internal_variable(context.return_type),
typ=context.return_type,
location="memory",
)
setter = make_setter(new_sub, sub, "memory", pos=getpos(stmt))
return LLLnode.from_list(
[
"seq",
setter,
make_return_stmt(
stmt,
context,
new_sub,
get_size_of_type(context.return_type) * 32,
),
],
typ=None,
pos=getpos(stmt),
)
# in case of multi we can't create a variable to store location of the return expression
# as multi can have data from multiple location like store, calldata etc
encode_out = abi_encode(return_buffer,
sub,
pos=getpos(stmt),
returns=True)
load_return_len = ["mload", MemoryPositions.FREE_VAR_SPACE]
os = [
"seq",
["mstore", MemoryPositions.FREE_VAR_SPACE, encode_out],
make_return_stmt(stmt, context, return_buffer, load_return_len),
]
return LLLnode.from_list(os, typ=None, pos=getpos(stmt), valency=0)
# for tuple return types where a function is called inside the tuple, we
# process the calls prior to encoding the return data
if sub.value == "seq_unchecked" and sub.args[-1].value == "multi":
encode_out = abi_encode(return_buffer,
sub.args[-1],
pos=getpos(stmt),
returns=True)
load_return_len = ["mload", MemoryPositions.FREE_VAR_SPACE]
os = (["seq"] + sub.args[:-1] + [
["mstore", MemoryPositions.FREE_VAR_SPACE, encode_out],
make_return_stmt(stmt, context, return_buffer, load_return_len),
])
return LLLnode.from_list(os, typ=None, pos=getpos(stmt), valency=0)
# for all othe cases we are creating a stack variable named sub_loc to store the location
# of the return expression. This is done so that the return expression does not get evaluated
# abi-encode uses a function named o_list which evaluate the expression multiple times
sub_loc = LLLnode("sub_loc", typ=sub.typ, location=sub.location)
encode_out = abi_encode(return_buffer,
sub_loc,
pos=getpos(stmt),
returns=True)
load_return_len = ["mload", MemoryPositions.FREE_VAR_SPACE]
os = [
"with",
"sub_loc",
sub,
[
"seq",
["mstore", MemoryPositions.FREE_VAR_SPACE, encode_out],
make_return_stmt(stmt, context, return_buffer, load_return_len),
],
]
return LLLnode.from_list(os, typ=None, pos=getpos(stmt), valency=0)
def abi_encode(dst, lll_node, pos=None, bufsz=None, returns=False):
parent_abi_t = abi_type_of(lll_node.typ)
size_bound = parent_abi_t.static_size() + parent_abi_t.dynamic_size_bound()
if bufsz is not None and bufsz < 32 * size_bound:
raise CompilerPanic("buffer provided to abi_encode not large enough")
lll_ret = ["seq"]
dyn_ofst = "dyn_ofst" # current offset in the dynamic section
dst_begin = "dst" # pointer to beginning of buffer
dst_loc = "dst_loc" # pointer to write location in static section
os = o_list(lll_node, pos=pos)
for i, o in enumerate(os):
abi_t = abi_type_of(o.typ)
if parent_abi_t.is_tuple():
if abi_t.is_dynamic():
lll_ret.append(["mstore", dst_loc, dyn_ofst])
# recurse
child_dst = ["add", dst_begin, dyn_ofst]
child = abi_encode(child_dst, o, pos=pos, returns=True)
# increment dyn ofst for the return
# (optimization note:
# if non-returning and this is the last dyn member in
# the tuple, this set can be elided.)
lll_ret.append(["set", dyn_ofst, ["add", dyn_ofst, child]])
else:
# recurse
lll_ret.append(abi_encode(dst_loc, o, pos=pos, returns=False))
elif isinstance(o.typ, BaseType):
d = LLLnode(dst_loc, typ=o.typ, location="memory")
lll_ret.append(make_setter(d, o, location=d.location, pos=pos))
elif isinstance(o.typ, ByteArrayLike):
d = LLLnode.from_list(dst_loc, typ=o.typ, location="memory")
lll_ret.append([
"seq",
make_setter(d, o, location=d.location, pos=pos),
zero_pad(d)
])
else:
raise CompilerPanic(f"unreachable type: {o.typ}")
if i + 1 == len(os):
pass # optimize out the last increment to dst_loc
else: # note: always false for non-tuple types
sz = abi_t.embedded_static_size()
lll_ret.append(["set", dst_loc, ["add", dst_loc, sz]])
# declare LLL variables.
if returns:
if not parent_abi_t.is_dynamic():
lll_ret.append(parent_abi_t.embedded_static_size())
elif parent_abi_t.is_tuple():
lll_ret.append("dyn_ofst")
elif isinstance(lll_node.typ, ByteArrayLike):
# for abi purposes, return zero-padded length
calc_len = ["ceil32", ["add", 32, ["mload", dst_loc]]]
lll_ret.append(calc_len)
else:
raise CompilerPanic("unknown type {lll_node.typ}")
if not (parent_abi_t.is_dynamic() and parent_abi_t.is_tuple()):
pass # optimize out dyn_ofst allocation if we don't need it
else:
dyn_section_start = parent_abi_t.static_size()
lll_ret = ["with", "dyn_ofst", dyn_section_start, lll_ret]
lll_ret = ["with", dst_begin, dst, ["with", dst_loc, dst_begin, lll_ret]]
return LLLnode.from_list(lll_ret)
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)
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