def gen_tuple_return(stmt, context, sub):
# Is from a call expression.
if sub.args and len(sub.args[0].args) > 0 and (
sub.args[0].args[0].value == "call"
or sub.args[0].args[0].value == "staticcall"):
# self-call to external.
mem_pos = sub
mem_size = get_size_of_type(sub.typ) * 32
return LLLnode.from_list(["return", mem_pos, mem_size], typ=sub.typ)
elif sub.annotation and "Internal Call" in sub.annotation:
mem_pos = sub.args[
-1].value if sub.value == "seq_unchecked" else sub.args[0].args[-1]
mem_size = get_size_of_type(sub.typ) * 32
# Add zero padder if bytes are present in output.
zero_padder = ["pass"]
byte_arrays = [(i, x) for i, x in enumerate(sub.typ.tuple_members())
if isinstance(x, ByteArrayLike)]
if byte_arrays:
i, x = byte_arrays[-1]
zero_padder = zero_pad(bytez_placeholder=[
"add", mem_pos, ["mload", mem_pos + i * 32]
])
return LLLnode.from_list(
["seq"] + [sub] + [zero_padder] +
[make_return_stmt(stmt, context, mem_pos, mem_size)],
typ=sub.typ,
pos=getpos(stmt),
valency=0,
)
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.increase_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))
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)
def pack_args_by_32(holder,
maxlen,
arg,
typ,
context,
placeholder,
dynamic_offset_counter=None,
datamem_start=None,
zero_pad_i=None,
pos=None):
"""
Copy necessary variables to pre-allocated memory section.
:param holder: Complete holder for all args
:param maxlen: Total length in bytes of the full arg section (static + dynamic).
:param arg: Current arg to pack
:param context: Context of arg
:param placeholder: Static placeholder for static argument part.
:param dynamic_offset_counter: position counter stored in static args.
:param dynamic_placeholder: pointer to current position in memory to write dynamic values to.
:param datamem_start: position where the whole datemem section starts.
"""
if isinstance(typ, BaseType):
if isinstance(arg, LLLnode):
value = unwrap_location(arg)
else:
value = Expr(arg, context).lll_node
value = base_type_conversion(value, value.typ, typ, pos)
holder.append(
LLLnode.from_list(['mstore', placeholder, value],
typ=typ,
location='memory'))
elif isinstance(typ, ByteArrayLike):
if isinstance(arg, LLLnode): # Is prealloacted variable.
source_lll = arg
else:
source_lll = Expr(arg, context).lll_node
# Set static offset, in arg slot.
holder.append(
LLLnode.from_list(
['mstore', placeholder, ['mload', dynamic_offset_counter]]))
# Get the biginning to write the ByteArray to.
dest_placeholder = LLLnode.from_list(
['add', datamem_start, ['mload', dynamic_offset_counter]],
typ=typ,
location='memory',
annotation="pack_args_by_32:dest_placeholder")
copier = make_byte_array_copier(dest_placeholder, source_lll, pos=pos)
holder.append(copier)
# Add zero padding.
holder.append(zero_pad(dest_placeholder, maxlen,
zero_pad_i=zero_pad_i))
# Increment offset counter.
increment_counter = LLLnode.from_list(
[
'mstore',
dynamic_offset_counter,
[
'add',
[
'add', ['mload', dynamic_offset_counter],
['ceil32', ['mload', dest_placeholder]]
],
32,
],
],
annotation='Increment dynamic offset counter')
holder.append(increment_counter)
elif isinstance(typ, ListType):
maxlen += (typ.count - 1) * 32
typ = typ.subtype
def check_list_type_match(provided): # Check list types match.
if provided != typ:
raise TypeMismatchException(
"Log list type '%s' does not match provided, expected '%s'"
% (provided, typ))
# NOTE: Below code could be refactored into iterators/getter functions for each type of
# repetitive loop. But seeing how each one is a unique for loop, and in which way
# the sub value makes the difference in each type of list clearer.
# List from storage
if isinstance(arg, ast.Attribute) and arg.value.id == 'self':
stor_list = context.globals[arg.attr]
check_list_type_match(stor_list.typ.subtype)
size = stor_list.typ.count
mem_offset = 0
for i in range(0, size):
storage_offset = i
arg2 = LLLnode.from_list(
[
'sload',
[
'add', ['sha3_32',
Expr(arg, context).lll_node],
storage_offset
]
],
typ=typ,
)
holder, maxlen = pack_args_by_32(
holder,
maxlen,
arg2,
typ,
context,
placeholder + mem_offset,
pos=pos,
)
mem_offset += get_size_of_type(typ) * 32
# List from variable.
elif isinstance(arg, ast.Name):
size = context.vars[arg.id].size
pos = context.vars[arg.id].pos
check_list_type_match(context.vars[arg.id].typ.subtype)
mem_offset = 0
for _ in range(0, size):
arg2 = LLLnode.from_list(
pos + mem_offset,
typ=typ,
location=context.vars[arg.id].location)
holder, maxlen = pack_args_by_32(
holder,
maxlen,
arg2,
typ,
context,
placeholder + mem_offset,
pos=pos,
)
mem_offset += get_size_of_type(typ) * 32
# List from list literal.
else:
mem_offset = 0
for arg2 in arg.elts:
holder, maxlen = pack_args_by_32(
holder,
maxlen,
arg2,
typ,
context,
placeholder + mem_offset,
pos=pos,
)
mem_offset += get_size_of_type(typ) * 32
return holder, maxlen
def parse_return(self):
if self.context.return_type is None:
if self.stmt.value:
raise TypeMismatchException("Not expecting to return a value",
self.stmt)
return LLLnode.from_list(
make_return_stmt(self.stmt, self.context, 0, 0),
typ=None,
pos=getpos(self.stmt),
valency=0,
)
if not self.stmt.value:
raise TypeMismatchException("Expecting to return a value",
self.stmt)
sub = Expr(self.stmt.value, self.context).lll_node
# Returning a value (most common case)
if isinstance(sub.typ, BaseType):
sub = unwrap_location(sub)
if not isinstance(self.context.return_type, BaseType):
raise TypeMismatchException(
f"Return type units mismatch {sub.typ} {self.context.return_type}",
self.stmt.value)
elif self.context.return_type != sub.typ and not sub.typ.is_literal:
raise TypeMismatchException(
f"Trying to return base type {sub.typ}, output expecting "
f"{self.context.return_type}",
self.stmt.value,
)
elif sub.typ.is_literal and (
self.context.return_type.typ == sub.typ
or 'int' in self.context.return_type.typ
and 'int' in sub.typ.typ): # noqa: E501
if not SizeLimits.in_bounds(self.context.return_type.typ,
sub.value):
raise InvalidLiteralException(
"Number out of range: " + str(sub.value), self.stmt)
else:
return LLLnode.from_list(
[
'seq', ['mstore', 0, sub],
make_return_stmt(self.stmt, self.context, 0, 32)
],
typ=None,
pos=getpos(self.stmt),
valency=0,
)
elif is_base_type(sub.typ, self.context.return_type.typ) or (
is_base_type(sub.typ, 'int128') and is_base_type(
self.context.return_type, 'int256')): # noqa: E501
return LLLnode.from_list(
[
'seq', ['mstore', 0, sub],
make_return_stmt(self.stmt, self.context, 0, 32)
],
typ=None,
pos=getpos(self.stmt),
valency=0,
)
else:
raise TypeMismatchException(
f"Unsupported type conversion: {sub.typ} to {self.context.return_type}",
self.stmt.value,
)
# Returning a byte array
elif isinstance(sub.typ, ByteArrayLike):
if not sub.typ.eq_base(self.context.return_type):
raise TypeMismatchException(
f"Trying to return base type {sub.typ}, output expecting "
f"{self.context.return_type}",
self.stmt.value,
)
if sub.typ.maxlen > self.context.return_type.maxlen:
raise TypeMismatchException(
f"Cannot cast from greater max-length {sub.typ.maxlen} to shorter "
f"max-length {self.context.return_type.maxlen}",
self.stmt.value,
)
# loop memory has to be allocated first.
loop_memory_position = self.context.new_placeholder(
typ=BaseType('uint256'))
# len & bytez placeholder have to be declared after each other at all times.
len_placeholder = self.context.new_placeholder(
typ=BaseType('uint256'))
bytez_placeholder = self.context.new_placeholder(typ=sub.typ)
if sub.location in ('storage', 'memory'):
return LLLnode.from_list([
'seq',
make_byte_array_copier(LLLnode(
bytez_placeholder, location='memory', typ=sub.typ),
sub,
pos=getpos(self.stmt)),
zero_pad(bytez_placeholder),
['mstore', len_placeholder, 32],
make_return_stmt(
self.stmt,
self.context,
len_placeholder,
['ceil32', ['add', ['mload', bytez_placeholder], 64]],
loop_memory_position=loop_memory_position,
)
],
typ=None,
pos=getpos(self.stmt),
valency=0)
else:
raise Exception(f"Invalid location: {sub.location}")
elif isinstance(sub.typ, ListType):
sub_base_type = re.split(r'\(|\[', str(sub.typ.subtype))[0]
ret_base_type = re.split(r'\(|\[',
str(self.context.return_type.subtype))[0]
loop_memory_position = self.context.new_placeholder(
typ=BaseType('uint256'))
if sub_base_type != ret_base_type:
raise TypeMismatchException(
f"List return type {sub_base_type} does not match specified "
f"return type, expecting {ret_base_type}", self.stmt)
elif sub.location == "memory" and sub.value != "multi":
return LLLnode.from_list(
make_return_stmt(
self.stmt,
self.context,
sub,
get_size_of_type(self.context.return_type) * 32,
loop_memory_position=loop_memory_position,
),
typ=None,
pos=getpos(self.stmt),
valency=0,
)
else:
new_sub = LLLnode.from_list(
self.context.new_placeholder(self.context.return_type),
typ=self.context.return_type,
location='memory',
)
setter = make_setter(new_sub,
sub,
'memory',
pos=getpos(self.stmt))
return LLLnode.from_list([
'seq', setter,
make_return_stmt(
self.stmt,
self.context,
new_sub,
get_size_of_type(self.context.return_type) * 32,
loop_memory_position=loop_memory_position,
)
],
typ=None,
pos=getpos(self.stmt))
# Returning a struct
elif isinstance(sub.typ, StructType):
retty = self.context.return_type
if not isinstance(retty, StructType) or retty.name != sub.typ.name:
raise TypeMismatchException(
f"Trying to return {sub.typ}, output expecting {self.context.return_type}",
self.stmt.value,
)
return gen_tuple_return(self.stmt, self.context, sub)
# Returning a tuple.
elif isinstance(sub.typ, TupleType):
if not isinstance(self.context.return_type, TupleType):
raise TypeMismatchException(
f"Trying to return tuple type {sub.typ}, output expecting "
f"{self.context.return_type}",
self.stmt.value,
)
if len(self.context.return_type.members) != len(sub.typ.members):
raise StructureException("Tuple lengths don't match!",
self.stmt)
# check return type matches, sub type.
for i, ret_x in enumerate(self.context.return_type.members):
s_member = sub.typ.members[i]
sub_type = s_member if isinstance(s_member,
NodeType) else s_member.typ
if type(sub_type) is not type(ret_x):
raise StructureException(
"Tuple return type does not match annotated return. "
f"{type(sub_type)} != {type(ret_x)}", self.stmt)
return gen_tuple_return(self.stmt, self.context, sub)
else:
raise TypeMismatchException(f"Can't return type {sub.typ}",
self.stmt)
def parse_Return(self):
if self.context.return_type is None:
if self.stmt.value:
return
return LLLnode.from_list(
make_return_stmt(self.stmt, self.context, 0, 0),
typ=None,
pos=getpos(self.stmt),
valency=0,
)
sub = Expr(self.stmt.value, self.context).lll_node
# Returning a value (most common case)
if isinstance(sub.typ, BaseType):
sub = unwrap_location(sub)
if self.context.return_type != sub.typ and not sub.typ.is_literal:
return
elif sub.typ.is_literal and (
self.context.return_type.typ == sub.typ
or "int" in self.context.return_type.typ
and "int" in sub.typ.typ): # noqa: E501
if SizeLimits.in_bounds(self.context.return_type.typ,
sub.value):
return LLLnode.from_list(
[
"seq",
["mstore", 0, sub],
make_return_stmt(self.stmt, self.context, 0, 32),
],
typ=None,
pos=getpos(self.stmt),
valency=0,
)
elif is_base_type(sub.typ, self.context.return_type.typ) or (
is_base_type(sub.typ, "int128") and is_base_type(
self.context.return_type, "int256")): # noqa: E501
return LLLnode.from_list(
[
"seq", ["mstore", 0, sub],
make_return_stmt(self.stmt, self.context, 0, 32)
],
typ=None,
pos=getpos(self.stmt),
valency=0,
)
return
# Returning a byte array
elif isinstance(sub.typ, ByteArrayLike):
if not sub.typ.eq_base(self.context.return_type):
return
if sub.typ.maxlen > self.context.return_type.maxlen:
return
# loop memory has to be allocated first.
loop_memory_position = self.context.new_placeholder(
typ=BaseType("uint256"))
# len & bytez placeholder have to be declared after each other at all times.
len_placeholder = self.context.new_placeholder(
typ=BaseType("uint256"))
bytez_placeholder = self.context.new_placeholder(typ=sub.typ)
if sub.location in ("storage", "memory"):
return LLLnode.from_list(
[
"seq",
make_byte_array_copier(
LLLnode(bytez_placeholder,
location="memory",
typ=sub.typ),
sub,
pos=getpos(self.stmt),
),
zero_pad(bytez_placeholder),
["mstore", len_placeholder, 32],
make_return_stmt(
self.stmt,
self.context,
len_placeholder,
[
"ceil32",
["add", ["mload", bytez_placeholder], 64]
],
loop_memory_position=loop_memory_position,
),
],
typ=None,
pos=getpos(self.stmt),
valency=0,
)
return
elif isinstance(sub.typ, ListType):
loop_memory_position = self.context.new_placeholder(
typ=BaseType("uint256"))
if sub.typ != self.context.return_type:
return
elif sub.location == "memory" and sub.value != "multi":
return LLLnode.from_list(
make_return_stmt(
self.stmt,
self.context,
sub,
get_size_of_type(self.context.return_type) * 32,
loop_memory_position=loop_memory_position,
),
typ=None,
pos=getpos(self.stmt),
valency=0,
)
else:
new_sub = LLLnode.from_list(
self.context.new_placeholder(self.context.return_type),
typ=self.context.return_type,
location="memory",
)
setter = make_setter(new_sub,
sub,
"memory",
pos=getpos(self.stmt))
return LLLnode.from_list(
[
"seq",
setter,
make_return_stmt(
self.stmt,
self.context,
new_sub,
get_size_of_type(self.context.return_type) * 32,
loop_memory_position=loop_memory_position,
),
],
typ=None,
pos=getpos(self.stmt),
)
# Returning a struct
elif isinstance(sub.typ, StructType):
retty = self.context.return_type
if isinstance(retty, StructType) and retty.name == sub.typ.name:
return gen_tuple_return(self.stmt, self.context, sub)
# Returning a tuple.
elif isinstance(sub.typ, TupleType):
if not isinstance(self.context.return_type, TupleType):
return
if len(self.context.return_type.members) != len(sub.typ.members):
return
# check return type matches, sub type.
for i, ret_x in enumerate(self.context.return_type.members):
s_member = sub.typ.members[i]
sub_type = s_member if isinstance(s_member,
NodeType) else s_member.typ
if type(sub_type) is not type(ret_x):
return
return gen_tuple_return(self.stmt, self.context, sub)
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 pack_args_by_32(
holder,
maxlen,
arg,
typ,
context,
placeholder,
dynamic_offset_counter=None,
datamem_start=None,
pos=None,
):
"""
Copy necessary variables to pre-allocated memory section.
:param holder: Complete holder for all args
:param maxlen: Total length in bytes of the full arg section (static + dynamic).
:param arg: Current arg to pack
:param context: Context of arg
:param placeholder: Static placeholder for static argument part.
:param dynamic_offset_counter: position counter stored in static args.
:param dynamic_placeholder: pointer to current position in memory to write dynamic values to.
:param datamem_start: position where the whole datemem section starts.
"""
if typ.size_in_bytes == 32:
if isinstance(arg, LLLnode):
value = unwrap_location(arg)
else:
value = Expr(arg, context).lll_node
value = base_type_conversion(value, value.typ, value.typ, pos)
holder.append(
LLLnode.from_list(["mstore", placeholder, value],
location="memory"))
elif isinstance(typ, ArrayValueAbstractType):
if isinstance(arg, LLLnode): # Is prealloacted variable.
source_lll = arg
else:
source_lll = Expr(arg, context).lll_node
# Set static offset, in arg slot.
holder.append(
LLLnode.from_list(
["mstore", placeholder, ["mload", dynamic_offset_counter]]))
# Get the beginning to write the ByteArray to.
# TODO refactor out the use of `ByteArrayLike` once old types are removed from parser
dest_placeholder = LLLnode.from_list(
["add", datamem_start, ["mload", dynamic_offset_counter]],
typ=ByteArrayLike(typ.length),
location="memory",
annotation="pack_args_by_32:dest_placeholder",
)
copier = make_byte_array_copier(dest_placeholder, source_lll, pos=pos)
holder.append(copier)
# Add zero padding.
holder.append(zero_pad(dest_placeholder))
# Increment offset counter.
increment_counter = LLLnode.from_list(
[
"mstore",
dynamic_offset_counter,
[
"add",
[
"add",
["mload", dynamic_offset_counter],
["ceil32", ["mload", dest_placeholder]],
],
32,
],
],
annotation="Increment dynamic offset counter",
)
holder.append(increment_counter)
elif isinstance(typ, ArrayDefinition):
if isinstance(arg, vy_ast.Call) and arg.func.get("id") == "empty":
# special case for `empty()` with a static-sized array
holder.append(mzero(placeholder, typ.size_in_bytes))
maxlen += typ.size_in_bytes - 32
return holder, maxlen
maxlen += (typ.length - 1) * 32
typ = typ.value_type
# NOTE: Below code could be refactored into iterators/getter functions for each type of
# repetitive loop. But seeing how each one is a unique for loop, and in which way
# the sub value makes the difference in each type of list clearer.
# List from storage
if isinstance(arg, vy_ast.Attribute) and arg.value.id == "self":
stor_list = context.globals[arg.attr]
size = stor_list.typ.count
mem_offset = 0
for i in range(0, size):
storage_offset = i
arg2 = LLLnode.from_list([
"sload",
[
"add", ["sha3_32",
Expr(arg, context).lll_node], storage_offset
]
], )
holder, maxlen = pack_args_by_32(
holder,
maxlen,
arg2,
typ,
context,
placeholder + mem_offset,
pos=pos,
)
mem_offset += typ.size_in_bytes
# List from variable.
elif isinstance(arg, vy_ast.Name):
size = context.vars[arg.id].size
pos = context.vars[arg.id].pos
mem_offset = 0
for _ in range(0, size):
arg2 = LLLnode.from_list(
pos + mem_offset, location=context.vars[arg.id].location)
holder, maxlen = pack_args_by_32(
holder,
maxlen,
arg2,
typ,
context,
placeholder + mem_offset,
pos=pos,
)
mem_offset += typ.size_in_bytes
# List from list literal.
else:
mem_offset = 0
for arg2 in arg.elements:
holder, maxlen = pack_args_by_32(
holder,
maxlen,
arg2,
typ,
context,
placeholder + mem_offset,
pos=pos,
)
mem_offset += typ.size_in_bytes
return holder, maxlen
