solidity/libsolidity/codegen/YulUtilFunctions.cpp

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/*
This file is part of solidity.
solidity is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
solidity is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with solidity. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* Component that can generate various useful Yul functions.
*/
#include <libsolidity/codegen/YulUtilFunctions.h>
#include <libsolidity/codegen/MultiUseYulFunctionCollector.h>
#include <libsolidity/ast/AST.h>
#include <libsolidity/codegen/CompilerUtils.h>
#include <libdevcore/Whiskers.h>
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#include <libdevcore/StringUtils.h>
#include <boost/algorithm/string/join.hpp>
#include <boost/range/adaptor/reversed.hpp>
using namespace std;
using namespace dev;
using namespace dev::solidity;
string YulUtilFunctions::combineExternalFunctionIdFunction()
{
string functionName = "combine_external_function_id";
return m_functionCollector->createFunction(functionName, [&]() {
return Whiskers(R"(
function <functionName>(addr, selector) -> combined {
combined := <shl64>(or(<shl32>(addr), and(selector, 0xffffffff)))
}
)")
("functionName", functionName)
("shl32", shiftLeftFunction(32))
("shl64", shiftLeftFunction(64))
.render();
});
}
string YulUtilFunctions::splitExternalFunctionIdFunction()
{
string functionName = "split_external_function_id";
return m_functionCollector->createFunction(functionName, [&]() {
return Whiskers(R"(
function <functionName>(combined) -> addr, selector {
combined := <shr64>(combined)
selector := and(combined, 0xffffffff)
addr := <shr32>(combined)
}
)")
("functionName", functionName)
("shr32", shiftRightFunction(32))
("shr64", shiftRightFunction(64))
.render();
});
}
string YulUtilFunctions::copyToMemoryFunction(bool _fromCalldata)
{
string functionName = "copy_" + string(_fromCalldata ? "calldata" : "memory") + "_to_memory";
return m_functionCollector->createFunction(functionName, [&]() {
if (_fromCalldata)
{
return Whiskers(R"(
function <functionName>(src, dst, length) {
calldatacopy(dst, src, length)
// clear end
mstore(add(dst, length), 0)
}
)")
("functionName", functionName)
.render();
}
else
{
return Whiskers(R"(
function <functionName>(src, dst, length) {
let i := 0
for { } lt(i, length) { i := add(i, 32) }
{
mstore(add(dst, i), mload(add(src, i)))
}
if gt(i, length)
{
// clear end
mstore(add(dst, length), 0)
}
}
)")
("functionName", functionName)
.render();
}
});
}
string YulUtilFunctions::requireOrAssertFunction(bool _assert, Type const* _messageType)
{
string functionName =
string(_assert ? "assert_helper" : "require_helper") +
(_messageType ? ("_" + _messageType->identifier()) : "");
solAssert(!_assert || !_messageType, "Asserts can't have messages!");
return m_functionCollector->createFunction(functionName, [&]() {
if (!_messageType)
return Whiskers(R"(
function <functionName>(condition) {
if iszero(condition) { <invalidOrRevert> }
}
)")
("invalidOrRevert", _assert ? "invalid()" : "revert(0, 0)")
("functionName", functionName)
.render();
int const hashHeaderSize = 4;
int const byteSize = 8;
u256 const errorHash =
u256(FixedHash<hashHeaderSize>::Arith(
FixedHash<hashHeaderSize>(dev::keccak256("Error(string)"))
)) << (256 - hashHeaderSize * byteSize);
string const encodeFunc = ABIFunctions(m_evmVersion, m_functionCollector)
.tupleEncoder(
{_messageType},
{TypeProvider::stringMemory()}
);
return Whiskers(R"(
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function <functionName>(condition <messageVars>) {
if iszero(condition) {
let fmp := mload(<freeMemPointer>)
mstore(fmp, <errorHash>)
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let end := <abiEncodeFunc>(add(fmp, <hashHeaderSize>) <messageVars>)
revert(fmp, sub(end, fmp))
}
}
)")
("functionName", functionName)
("freeMemPointer", to_string(CompilerUtils::freeMemoryPointer))
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("errorHash", formatNumber(errorHash))
("abiEncodeFunc", encodeFunc)
("hashHeaderSize", to_string(hashHeaderSize))
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("messageVars",
(_messageType->sizeOnStack() > 0 ? ", " : "") +
suffixedVariableNameList("message_", 1, 1 + _messageType->sizeOnStack())
)
.render();
});
}
string YulUtilFunctions::leftAlignFunction(Type const& _type)
{
string functionName = string("leftAlign_") + _type.identifier();
return m_functionCollector->createFunction(functionName, [&]() {
Whiskers templ(R"(
function <functionName>(value) -> aligned {
<body>
}
)");
templ("functionName", functionName);
switch (_type.category())
{
case Type::Category::Address:
templ("body", "aligned := " + leftAlignFunction(IntegerType(160)) + "(value)");
break;
case Type::Category::Integer:
{
IntegerType const& type = dynamic_cast<IntegerType const&>(_type);
if (type.numBits() == 256)
templ("body", "aligned := value");
else
templ("body", "aligned := " + shiftLeftFunction(256 - type.numBits()) + "(value)");
break;
}
case Type::Category::RationalNumber:
solAssert(false, "Left align requested for rational number.");
break;
case Type::Category::Bool:
templ("body", "aligned := " + leftAlignFunction(IntegerType(8)) + "(value)");
break;
case Type::Category::FixedPoint:
solUnimplemented("Fixed point types not implemented.");
break;
case Type::Category::Array:
case Type::Category::Struct:
solAssert(false, "Left align requested for non-value type.");
break;
case Type::Category::FixedBytes:
templ("body", "aligned := value");
break;
case Type::Category::Contract:
templ("body", "aligned := " + leftAlignFunction(*TypeProvider::address()) + "(value)");
break;
case Type::Category::Enum:
{
unsigned storageBytes = dynamic_cast<EnumType const&>(_type).storageBytes();
templ("body", "aligned := " + leftAlignFunction(IntegerType(8 * storageBytes)) + "(value)");
break;
}
case Type::Category::InaccessibleDynamic:
solAssert(false, "Left align requested for inaccessible dynamic type.");
break;
default:
solAssert(false, "Left align of type " + _type.identifier() + " requested.");
}
return templ.render();
});
}
string YulUtilFunctions::shiftLeftFunction(size_t _numBits)
{
solAssert(_numBits < 256, "");
string functionName = "shift_left_" + to_string(_numBits);
return m_functionCollector->createFunction(functionName, [&]() {
return
Whiskers(R"(
function <functionName>(value) -> newValue {
newValue :=
<?hasShifts>
shl(<numBits>, value)
<!hasShifts>
mul(value, <multiplier>)
</hasShifts>
}
)")
("functionName", functionName)
("numBits", to_string(_numBits))
("hasShifts", m_evmVersion.hasBitwiseShifting())
("multiplier", toCompactHexWithPrefix(u256(1) << _numBits))
.render();
});
}
string YulUtilFunctions::shiftLeftFunctionDynamic()
{
string functionName = "shift_left_dynamic";
return m_functionCollector->createFunction(functionName, [&]() {
return
Whiskers(R"(
function <functionName>(bits, value) -> newValue {
newValue :=
<?hasShifts>
shl(bits, value)
<!hasShifts>
mul(value, exp(2, bits))
</hasShifts>
}
)")
("functionName", functionName)
("hasShifts", m_evmVersion.hasBitwiseShifting())
.render();
});
}
string YulUtilFunctions::shiftRightFunction(size_t _numBits)
{
solAssert(_numBits < 256, "");
// Note that if this is extended with signed shifts,
// the opcodes SAR and SDIV behave differently with regards to rounding!
string functionName = "shift_right_" + to_string(_numBits) + "_unsigned";
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return m_functionCollector->createFunction(functionName, [&]() {
return
Whiskers(R"(
function <functionName>(value) -> newValue {
newValue :=
<?hasShifts>
shr(<numBits>, value)
<!hasShifts>
div(value, <multiplier>)
</hasShifts>
}
)")
("functionName", functionName)
("hasShifts", m_evmVersion.hasBitwiseShifting())
("numBits", to_string(_numBits))
("multiplier", toCompactHexWithPrefix(u256(1) << _numBits))
.render();
});
}
string YulUtilFunctions::shiftRightFunctionDynamic()
{
// Note that if this is extended with signed shifts,
// the opcodes SAR and SDIV behave differently with regards to rounding!
string const functionName = "shift_right_unsigned_dynamic";
return m_functionCollector->createFunction(functionName, [&]() {
return
Whiskers(R"(
function <functionName>(bits, value) -> newValue {
newValue :=
<?hasShifts>
shr(bits, value)
<!hasShifts>
div(value, exp(2, bits))
</hasShifts>
}
)")
("functionName", functionName)
("hasShifts", m_evmVersion.hasBitwiseShifting())
.render();
});
}
string YulUtilFunctions::updateByteSliceFunction(size_t _numBytes, size_t _shiftBytes)
{
solAssert(_numBytes <= 32, "");
solAssert(_shiftBytes <= 32, "");
size_t numBits = _numBytes * 8;
size_t shiftBits = _shiftBytes * 8;
string functionName = "update_byte_slice_" + to_string(_numBytes) + "_shift_" + to_string(_shiftBytes);
return m_functionCollector->createFunction(functionName, [&]() {
return
Whiskers(R"(
function <functionName>(value, toInsert) -> result {
let mask := <mask>
toInsert := <shl>(toInsert)
value := and(value, not(mask))
result := or(value, and(toInsert, mask))
}
)")
("functionName", functionName)
("mask", formatNumber(((bigint(1) << numBits) - 1) << shiftBits))
("shl", shiftLeftFunction(shiftBits))
.render();
});
}
string YulUtilFunctions::updateByteSliceFunctionDynamic(size_t _numBytes)
{
solAssert(_numBytes <= 32, "");
size_t numBits = _numBytes * 8;
string functionName = "update_byte_slice_dynamic" + to_string(_numBytes);
return m_functionCollector->createFunction(functionName, [&]() {
return
Whiskers(R"(
function <functionName>(value, shiftBytes, toInsert) -> result {
let shiftBits := mul(shiftBytes, 8)
let mask := <shl>(shiftBits, <mask>)
toInsert := <shl>(shiftBits, toInsert)
value := and(value, not(mask))
result := or(value, and(toInsert, mask))
}
)")
("functionName", functionName)
("mask", formatNumber((bigint(1) << numBits) - 1))
("shl", shiftLeftFunctionDynamic())
.render();
});
}
string YulUtilFunctions::roundUpFunction()
{
string functionName = "round_up_to_mul_of_32";
return m_functionCollector->createFunction(functionName, [&]() {
return
Whiskers(R"(
function <functionName>(value) -> result {
result := and(add(value, 31), not(31))
}
)")
("functionName", functionName)
.render();
});
}
string YulUtilFunctions::overflowCheckedIntAddFunction(IntegerType const& _type)
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{
string functionName = "checked_add_" + _type.identifier();
// TODO: Consider to add a special case for unsigned 256-bit integers
// and use the following instead:
// sum := add(x, y) if lt(sum, x) { revert(0, 0) }
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return m_functionCollector->createFunction(functionName, [&]() {
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return
Whiskers(R"(
function <functionName>(x, y) -> sum {
<?signed>
// overflow, if x >= 0 and y > (maxValue - x)
if and(iszero(slt(x, 0)), sgt(y, sub(<maxValue>, x))) { revert(0, 0) }
// underflow, if x < 0 and y < (minValue - x)
if and(slt(x, 0), slt(y, sub(<minValue>, x))) { revert(0, 0) }
<!signed>
// overflow, if x > (maxValue - y)
if gt(x, sub(<maxValue>, y)) { revert(0, 0) }
</signed>
sum := add(x, y)
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}
)")
("functionName", functionName)
("signed", _type.isSigned())
("maxValue", toCompactHexWithPrefix(u256(_type.maxValue())))
("minValue", toCompactHexWithPrefix(u256(_type.minValue())))
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.render();
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});
}
string YulUtilFunctions::overflowCheckedIntMulFunction(IntegerType const& _type)
{
string functionName = "checked_mul_" + _type.identifier();
return m_functionCollector->createFunction(functionName, [&]() {
return
// Multiplication by zero could be treated separately and directly return zero.
Whiskers(R"(
function <functionName>(x, y) -> product {
<?signed>
// overflow, if x > 0, y > 0 and x > (maxValue / y)
if and(and(sgt(x, 0), sgt(y, 0)), gt(x, div(<maxValue>, y))) { revert(0, 0) }
// underflow, if x > 0, y < 0 and y < (minValue / x)
if and(and(sgt(x, 0), slt(y, 0)), slt(y, sdiv(<minValue>, x))) { revert(0, 0) }
// underflow, if x < 0, y > 0 and x < (minValue / y)
if and(and(slt(x, 0), sgt(y, 0)), slt(x, sdiv(<minValue>, y))) { revert(0, 0) }
// overflow, if x < 0, y < 0 and x < (maxValue / y)
if and(and(slt(x, 0), slt(y, 0)), slt(x, sdiv(<maxValue>, y))) { revert(0, 0) }
<!signed>
// overflow, if x != 0 and y > (maxValue / x)
if and(iszero(iszero(x)), gt(y, div(<maxValue>, x))) { revert(0, 0) }
</signed>
product := mul(x, y)
}
)")
("functionName", functionName)
("signed", _type.isSigned())
("maxValue", toCompactHexWithPrefix(u256(_type.maxValue())))
("minValue", toCompactHexWithPrefix(u256(_type.minValue())))
.render();
});
}
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string YulUtilFunctions::overflowCheckedIntDivFunction(IntegerType const& _type)
{
string functionName = "checked_div_" + _type.identifier();
return m_functionCollector->createFunction(functionName, [&]() {
return
Whiskers(R"(
function <functionName>(x, y) -> r {
if iszero(y) { revert(0, 0) }
<?signed>
// overflow for minVal / -1
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if and(
eq(x, <minVal>),
eq(y, sub(0, 1))
) { revert(0, 0) }
</signed>
r := <?signed>s</signed>div(x, y)
}
)")
("functionName", functionName)
("signed", _type.isSigned())
("minVal", toCompactHexWithPrefix(u256(_type.minValue())))
.render();
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});
}
string YulUtilFunctions::checkedIntModFunction(IntegerType const& _type)
{
string functionName = "checked_mod_" + _type.identifier();
return m_functionCollector->createFunction(functionName, [&]() {
return
Whiskers(R"(
function <functionName>(x, y) -> r {
if iszero(y) { revert(0, 0) }
r := <?signed>s</signed>mod(x, y)
}
)")
("functionName", functionName)
("signed", _type.isSigned())
.render();
});
}
string YulUtilFunctions::overflowCheckedIntSubFunction(IntegerType const& _type)
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{
string functionName = "checked_sub_" + _type.identifier();
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return m_functionCollector->createFunction(functionName, [&] {
return
Whiskers(R"(
function <functionName>(x, y) -> diff {
<?signed>
// underflow, if y >= 0 and x < (minValue + y)
if and(iszero(slt(y, 0)), slt(x, add(<minValue>, y))) { revert(0, 0) }
// overflow, if y < 0 and x > (maxValue + y)
if and(slt(y, 0), sgt(x, add(<maxValue>, y))) { revert(0, 0) }
<!signed>
if lt(x, y) { revert(0, 0) }
</signed>
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diff := sub(x, y)
}
)")
("functionName", functionName)
("signed", _type.isSigned())
("maxValue", toCompactHexWithPrefix(u256(_type.maxValue())))
("minValue", toCompactHexWithPrefix(u256(_type.minValue())))
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.render();
});
}
string YulUtilFunctions::arrayLengthFunction(ArrayType const& _type)
{
string functionName = "array_length_" + _type.identifier();
return m_functionCollector->createFunction(functionName, [&]() {
Whiskers w(R"(
function <functionName>(value) -> length {
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<?dynamic>
<?memory>
length := mload(value)
</memory>
<?storage>
length := sload(value)
<?byteArray>
// Retrieve length both for in-place strings and off-place strings:
// Computes (x & (0x100 * (ISZERO (x & 1)) - 1)) / 2
// i.e. for short strings (x & 1 == 0) it does (x & 0xff) / 2 and for long strings it
// computes (x & (-1)) / 2, which is equivalent to just x / 2.
let mask := sub(mul(0x100, iszero(and(length, 1))), 1)
length := div(and(length, mask), 2)
</byteArray>
</storage>
<!dynamic>
length := <length>
</dynamic>
}
)");
w("functionName", functionName);
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w("dynamic", _type.isDynamicallySized());
if (!_type.isDynamicallySized())
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w("length", toCompactHexWithPrefix(_type.length()));
w("memory", _type.location() == DataLocation::Memory);
w("storage", _type.location() == DataLocation::Storage);
w("byteArray", _type.isByteArray());
if (_type.isDynamicallySized())
solAssert(
_type.location() != DataLocation::CallData,
"called regular array length function on calldata array"
);
return w.render();
});
}
std::string YulUtilFunctions::resizeDynamicArrayFunction(ArrayType const& _type)
{
solAssert(_type.location() == DataLocation::Storage, "");
solAssert(_type.isDynamicallySized(), "");
solUnimplementedAssert(!_type.isByteArray(), "Byte Arrays not yet implemented!");
solUnimplementedAssert(_type.baseType()->storageBytes() <= 32, "...");
solUnimplementedAssert(_type.baseType()->storageSize() == 1, "");
string functionName = "resize_array_" + _type.identifier();
return m_functionCollector->createFunction(functionName, [&]() {
return Whiskers(R"(
function <functionName>(array, newLen) {
if gt(newLen, <maxArrayLength>) {
invalid()
}
let oldLen := <fetchLength>(array)
// Store new length
sstore(array, newLen)
// Size was reduced, clear end of array
if lt(newLen, oldLen) {
let oldSlotCount := <convertToSize>(oldLen)
let newSlotCount := <convertToSize>(newLen)
let arrayDataStart := <dataPosition>(array)
let deleteStart := add(arrayDataStart, newSlotCount)
let deleteEnd := add(arrayDataStart, oldSlotCount)
<clearStorageRange>(deleteStart, deleteEnd)
}
})")
("functionName", functionName)
("fetchLength", arrayLengthFunction(_type))
("convertToSize", arrayConvertLengthToSize(_type))
("dataPosition", arrayDataAreaFunction(_type))
("clearStorageRange", clearStorageRangeFunction(*_type.baseType()))
("maxArrayLength", (u256(1) << 64).str())
.render();
});
}
string YulUtilFunctions::clearStorageRangeFunction(Type const& _type)
{
string functionName = "clear_storage_range_" + _type.identifier();
solAssert(_type.storageBytes() >= 32, "Expected smaller value for storage bytes");
return m_functionCollector->createFunction(functionName, [&]() {
return Whiskers(R"(
function <functionName>(start, end) {
for {} lt(start, end) { start := add(start, <increment>) }
{
<setToZero>(start, 0)
}
}
)")
("functionName", functionName)
("setToZero", storageSetToZeroFunction(_type))
("increment", _type.storageSize().str())
.render();
});
}
string YulUtilFunctions::clearStorageArrayFunction(ArrayType const& _type)
{
solAssert(_type.location() == DataLocation::Storage, "");
if (_type.baseType()->storageBytes() < 32)
{
solAssert(_type.baseType()->isValueType(), "Invalid storage size for non-value type.");
solAssert(_type.baseType()->storageSize() <= 1, "Invalid storage size for type.");
}
if (_type.baseType()->isValueType())
solAssert(_type.baseType()->storageSize() <= 1, "Invalid size for value type.");
string functionName = "clear_storage_array_" + _type.identifier();
return m_functionCollector->createFunction(functionName, [&]() {
return Whiskers(R"(
function <functionName>(slot) {
<?dynamic>
<resizeArray>(slot, 0)
<!dynamic>
<clearRange>(slot, add(slot, <lenToSize>(<len>)))
</dynamic>
}
)")
("functionName", functionName)
("dynamic", _type.isDynamicallySized())
("resizeArray", _type.isDynamicallySized() ? resizeDynamicArrayFunction(_type) : "")
(
"clearRange",
clearStorageRangeFunction(
(_type.baseType()->storageBytes() < 32) ?
*TypeProvider::uint256() :
*_type.baseType()
)
)
("lenToSize", arrayConvertLengthToSize(_type))
("len", _type.length().str())
.render();
});
}
string YulUtilFunctions::arrayConvertLengthToSize(ArrayType const& _type)
{
string functionName = "array_convert_length_to_size_" + _type.identifier();
return m_functionCollector->createFunction(functionName, [&]() {
Type const& baseType = *_type.baseType();
switch (_type.location())
{
case DataLocation::Storage:
{
unsigned const baseStorageBytes = baseType.storageBytes();
solAssert(baseStorageBytes > 0, "");
solAssert(32 / baseStorageBytes > 0, "");
return Whiskers(R"(
function <functionName>(length) -> size {
size := length
<?multiSlot>
size := <mul>(<storageSize>, length)
<!multiSlot>
// Number of slots rounded up
size := div(add(length, sub(<itemsPerSlot>, 1)), <itemsPerSlot>)
</multiSlot>
})")
("functionName", functionName)
("multiSlot", baseType.storageSize() > 1)
("itemsPerSlot", to_string(32 / baseStorageBytes))
("storageSize", baseType.storageSize().str())
("mul", overflowCheckedIntMulFunction(*TypeProvider::uint256()))
.render();
}
case DataLocation::CallData: // fallthrough
case DataLocation::Memory:
return Whiskers(R"(
function <functionName>(length) -> size {
<?byteArray>
size := length
<!byteArray>
size := <mul>(length, <stride>)
</byteArray>
})")
("functionName", functionName)
("stride", to_string(_type.location() == DataLocation::Memory ? _type.memoryStride() : _type.calldataStride()))
("byteArray", _type.isByteArray())
("mul", overflowCheckedIntMulFunction(*TypeProvider::uint256()))
.render();
default:
solAssert(false, "");
}
});
}
string YulUtilFunctions::arrayAllocationSizeFunction(ArrayType const& _type)
{
solAssert(_type.dataStoredIn(DataLocation::Memory), "");
string functionName = "array_allocation_size_" + _type.identifier();
return m_functionCollector->createFunction(functionName, [&]() {
Whiskers w(R"(
function <functionName>(length) -> size {
// Make sure we can allocate memory without overflow
if gt(length, 0xffffffffffffffff) { revert(0, 0) }
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<?byteArray>
// round up
size := and(add(length, 0x1f), not(0x1f))
<!byteArray>
size := mul(length, 0x20)
</byteArray>
<?dynamic>
// add length slot
size := add(size, 0x20)
</dynamic>
}
)");
w("functionName", functionName);
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w("byteArray", _type.isByteArray());
w("dynamic", _type.isDynamicallySized());
return w.render();
});
}
string YulUtilFunctions::arrayDataAreaFunction(ArrayType const& _type)
{
string functionName = "array_dataslot_" + _type.identifier();
return m_functionCollector->createFunction(functionName, [&]() {
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// No special processing for calldata arrays, because they are stored as
// offset of the data area and length on the stack, so the offset already
// points to the data area.
// This might change, if calldata arrays are stored in a single
// stack slot at some point.
return Whiskers(R"(
function <functionName>(ptr) -> data {
data := ptr
<?dynamic>
<?memory>
data := add(ptr, 0x20)
</memory>
<?storage>
mstore(0, ptr)
data := keccak256(0, 0x20)
</storage>
</dynamic>
}
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)")
("functionName", functionName)
("dynamic", _type.isDynamicallySized())
("memory", _type.location() == DataLocation::Memory)
("storage", _type.location() == DataLocation::Storage)
.render();
});
}
string YulUtilFunctions::storageArrayIndexAccessFunction(ArrayType const& _type)
{
solUnimplementedAssert(_type.baseType()->storageBytes() > 16, "");
string functionName = "storage_array_index_access_" + _type.identifier();
return m_functionCollector->createFunction(functionName, [&]() {
return Whiskers(R"(
function <functionName>(array, index) -> slot, offset {
if iszero(lt(index, <arrayLen>(array))) {
invalid()
}
let data := <dataAreaFunc>(array)
<?multipleItemsPerSlot>
<!multipleItemsPerSlot>
slot := add(data, mul(index, <storageSize>))
offset := 0
</multipleItemsPerSlot>
}
)")
("functionName", functionName)
("arrayLen", arrayLengthFunction(_type))
("dataAreaFunc", arrayDataAreaFunction(_type))
("multipleItemsPerSlot", _type.baseType()->storageBytes() <= 16)
("storageSize", _type.baseType()->storageSize().str())
.render();
});
}
string YulUtilFunctions::memoryArrayIndexAccessFunction(ArrayType const& _type)
{
string functionName = "memory_array_index_access_" + _type.identifier();
return m_functionCollector->createFunction(functionName, [&]() {
return Whiskers(R"(
function <functionName>(baseRef, index) -> addr {
if iszero(lt(index, <arrayLen>(baseRef))) {
invalid()
}
let offset := mul(index, <stride>)
<?dynamicallySized>
offset := add(offset, 32)
</dynamicallySized>
addr := add(baseRef, offset)
}
)")
("functionName", functionName)
("arrayLen", arrayLengthFunction(_type))
("stride", to_string(_type.memoryStride()))
("dynamicallySized", _type.isDynamicallySized())
.render();
});
}
string YulUtilFunctions::calldataArrayIndexAccessFunction(ArrayType const& /*_type*/)
{
solUnimplemented("Calldata arrays not yet implemented!");
}
string YulUtilFunctions::nextArrayElementFunction(ArrayType const& _type)
{
solAssert(!_type.isByteArray(), "");
if (_type.dataStoredIn(DataLocation::Storage))
solAssert(_type.baseType()->storageBytes() > 16, "");
string functionName = "array_nextElement_" + _type.identifier();
return m_functionCollector->createFunction(functionName, [&]() {
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Whiskers templ(R"(
function <functionName>(ptr) -> next {
next := add(ptr, <advance>)
}
)");
templ("functionName", functionName);
switch (_type.location())
{
case DataLocation::Memory:
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templ("advance", "0x20");
break;
case DataLocation::Storage:
{
u256 size = _type.baseType()->storageSize();
solAssert(size >= 1, "");
templ("advance", toCompactHexWithPrefix(size));
break;
}
case DataLocation::CallData:
{
u256 size = _type.calldataStride();
solAssert(size >= 32 && size % 32 == 0, "");
templ("advance", toCompactHexWithPrefix(size));
break;
}
}
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return templ.render();
});
}
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string YulUtilFunctions::mappingIndexAccessFunction(MappingType const& _mappingType, Type const& _keyType)
{
solAssert(_keyType.sizeOnStack() <= 1, "");
string functionName = "mapping_index_access_" + _mappingType.identifier() + "_of_" + _keyType.identifier();
return m_functionCollector->createFunction(functionName, [&]() {
if (_mappingType.keyType()->isDynamicallySized())
return Whiskers(R"(
function <functionName>(slot <comma> <key>) -> dataSlot {
dataSlot := <hash>(slot <comma> <key>)
}
)")
("functionName", functionName)
("key", _keyType.sizeOnStack() > 0 ? "key" : "")
("comma", _keyType.sizeOnStack() > 0 ? "," : "")
("hash", packedHashFunction(
{&_keyType, TypeProvider::uint256()},
{_mappingType.keyType(), TypeProvider::uint256()}
))
.render();
else
{
solAssert(CompilerUtils::freeMemoryPointer >= 0x40, "");
solAssert(!_mappingType.keyType()->isDynamicallyEncoded(), "");
solAssert(_mappingType.keyType()->calldataEncodedSize(false) <= 0x20, "");
Whiskers templ(R"(
function <functionName>(slot <key>) -> dataSlot {
mstore(0, <convertedKey>)
mstore(0x20, slot)
dataSlot := keccak256(0, 0x40)
}
)");
templ("functionName", functionName);
templ("key", _keyType.sizeOnStack() == 1 ? ", key" : "");
if (_keyType.sizeOnStack() == 0)
templ("convertedKey", conversionFunction(_keyType, *_mappingType.keyType()) + "()");
else
templ("convertedKey", conversionFunction(_keyType, *_mappingType.keyType()) + "(key)");
return templ.render();
}
});
}
string YulUtilFunctions::readFromStorage(Type const& _type, size_t _offset, bool _splitFunctionTypes)
{
solUnimplementedAssert(!_splitFunctionTypes, "");
string functionName =
"read_from_storage_" +
string(_splitFunctionTypes ? "split_" : "") +
"offset_" +
to_string(_offset) +
"_" +
_type.identifier();
return m_functionCollector->createFunction(functionName, [&] {
solAssert(_type.sizeOnStack() == 1, "");
return Whiskers(R"(
function <functionName>(slot) -> value {
value := <extract>(sload(slot))
}
)")
("functionName", functionName)
("extract", extractFromStorageValue(_type, _offset, false))
.render();
});
}
string YulUtilFunctions::readFromStorageDynamic(Type const& _type, bool _splitFunctionTypes)
{
solUnimplementedAssert(!_splitFunctionTypes, "");
string functionName =
"read_from_storage_dynamic" +
string(_splitFunctionTypes ? "split_" : "") +
"_" +
_type.identifier();
return m_functionCollector->createFunction(functionName, [&] {
solAssert(_type.sizeOnStack() == 1, "");
return Whiskers(R"(
function <functionName>(slot, offset) -> value {
value := <extract>(sload(slot), offset)
}
)")
("functionName", functionName)
("extract", extractFromStorageValueDynamic(_type, _splitFunctionTypes))
.render();
});
}
string YulUtilFunctions::readFromMemory(Type const& _type)
{
return readFromMemoryOrCalldata(_type, false);
}
string YulUtilFunctions::readFromCalldata(Type const& _type)
{
return readFromMemoryOrCalldata(_type, true);
}
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string YulUtilFunctions::updateStorageValueFunction(Type const& _type, boost::optional<unsigned> const& _offset)
{
string const functionName =
"update_storage_value_" +
(_offset.is_initialized() ? ("offset_" + to_string(*_offset)) : "") +
_type.identifier();
return m_functionCollector->createFunction(functionName, [&] {
if (_type.isValueType())
{
solAssert(_type.storageBytes() <= 32, "Invalid storage bytes size.");
solAssert(_type.storageBytes() > 0, "Invalid storage bytes size.");
return Whiskers(R"(
function <functionName>(slot, <offset>value) {
sstore(slot, <update>(sload(slot), <offset><prepare>(value)))
}
)")
("functionName", functionName)
("update",
_offset.is_initialized() ?
updateByteSliceFunction(_type.storageBytes(), *_offset) :
updateByteSliceFunctionDynamic(_type.storageBytes())
)
("offset", _offset.is_initialized() ? "" : "offset, ")
("prepare", prepareStoreFunction(_type))
.render();
}
else
{
if (_type.category() == Type::Category::Array)
solUnimplementedAssert(false, "");
else if (_type.category() == Type::Category::Struct)
solUnimplementedAssert(false, "");
else
solAssert(false, "Invalid non-value type for assignment.");
}
});
}
string YulUtilFunctions::writeToMemoryFunction(Type const& _type)
{
string const functionName =
string("write_to_memory_") +
_type.identifier();
return m_functionCollector->createFunction(functionName, [&] {
solAssert(!dynamic_cast<StringLiteralType const*>(&_type), "");
if (auto ref = dynamic_cast<ReferenceType const*>(&_type))
{
solAssert(
ref->location() == DataLocation::Memory,
"Can only update types with location memory."
);
return Whiskers(R"(
function <functionName>(memPtr, value) {
mstore(memPtr, value)
}
)")
("functionName", functionName)
.render();
}
else if (
_type.category() == Type::Category::Function &&
dynamic_cast<FunctionType const&>(_type).kind() == FunctionType::Kind::External
)
{
return Whiskers(R"(
function <functionName>(memPtr, addr, selector) {
mstore(memPtr, <combine>(addr, selector))
}
)")
("functionName", functionName)
("combine", combineExternalFunctionIdFunction())
.render();
}
else if (_type.isValueType())
{
return Whiskers(R"(
function <functionName>(memPtr, value) {
mstore(memPtr, <cleanup>(value))
}
)")
("functionName", functionName)
("cleanup", cleanupFunction(_type))
.render();
}
else // Should never happen
{
solAssert(
false,
"Memory store of type " + _type.toString(true) + " not allowed."
);
}
});
}
string YulUtilFunctions::extractFromStorageValueDynamic(Type const& _type, bool _splitFunctionTypes)
{
solUnimplementedAssert(!_splitFunctionTypes, "");
string functionName =
"extract_from_storage_value_dynamic" +
string(_splitFunctionTypes ? "split_" : "") +
_type.identifier();
return m_functionCollector->createFunction(functionName, [&] {
return Whiskers(R"(
function <functionName>(slot_value, offset) -> value {
value := <cleanupStorage>(<shr>(mul(offset, 8), slot_value))
}
)")
("functionName", functionName)
("shr", shiftRightFunctionDynamic())
("cleanupStorage", cleanupFromStorageFunction(_type, _splitFunctionTypes))
.render();
});
}
string YulUtilFunctions::extractFromStorageValue(Type const& _type, size_t _offset, bool _splitFunctionTypes)
{
solUnimplementedAssert(!_splitFunctionTypes, "");
string functionName =
"extract_from_storage_value_" +
string(_splitFunctionTypes ? "split_" : "") +
"offset_" +
to_string(_offset) +
_type.identifier();
return m_functionCollector->createFunction(functionName, [&] {
return Whiskers(R"(
function <functionName>(slot_value) -> value {
value := <cleanupStorage>(<shr>(slot_value))
}
)")
("functionName", functionName)
("shr", shiftRightFunction(_offset * 8))
("cleanupStorage", cleanupFromStorageFunction(_type, _splitFunctionTypes))
.render();
});
}
string YulUtilFunctions::cleanupFromStorageFunction(Type const& _type, bool _splitFunctionTypes)
{
solAssert(_type.isValueType(), "");
solUnimplementedAssert(!_splitFunctionTypes, "");
string functionName = string("cleanup_from_storage_") + (_splitFunctionTypes ? "split_" : "") + _type.identifier();
return m_functionCollector->createFunction(functionName, [&] {
Whiskers templ(R"(
function <functionName>(value) -> cleaned {
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cleaned := <cleaned>
}
)");
templ("functionName", functionName);
unsigned storageBytes = _type.storageBytes();
if (IntegerType const* type = dynamic_cast<IntegerType const*>(&_type))
if (type->isSigned() && storageBytes != 32)
{
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templ("cleaned", "signextend(" + to_string(storageBytes - 1) + ", value)");
return templ.render();
}
if (storageBytes == 32)
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templ("cleaned", "value");
else if (_type.leftAligned())
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templ("cleaned", shiftLeftFunction(256 - 8 * storageBytes) + "(value)");
else
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templ("cleaned", "and(value, " + toCompactHexWithPrefix((u256(1) << (8 * storageBytes)) - 1) + ")");
return templ.render();
});
}
string YulUtilFunctions::prepareStoreFunction(Type const& _type)
{
solUnimplementedAssert(_type.category() != Type::Category::Function, "");
string functionName = "prepare_store_" + _type.identifier();
return m_functionCollector->createFunction(functionName, [&]() {
Whiskers templ(R"(
function <functionName>(value) -> ret {
ret := <actualPrepare>
}
)");
templ("functionName", functionName);
if (_type.category() == Type::Category::FixedBytes)
templ("actualPrepare", shiftRightFunction(256 - 8 * _type.storageBytes()) + "(value)");
else
templ("actualPrepare", "value");
return templ.render();
});
}
string YulUtilFunctions::allocationFunction()
{
string functionName = "allocateMemory";
return m_functionCollector->createFunction(functionName, [&]() {
return Whiskers(R"(
function <functionName>(size) -> memPtr {
memPtr := mload(<freeMemoryPointer>)
let newFreePtr := add(memPtr, size)
// protect against overflow
if or(gt(newFreePtr, 0xffffffffffffffff), lt(newFreePtr, memPtr)) { revert(0, 0) }
mstore(<freeMemoryPointer>, newFreePtr)
}
)")
("freeMemoryPointer", to_string(CompilerUtils::freeMemoryPointer))
("functionName", functionName)
.render();
});
}
string YulUtilFunctions::allocateMemoryArrayFunction(ArrayType const& _type)
{
solUnimplementedAssert(!_type.isByteArray(), "");
string functionName = "allocate_memory_array_" + _type.identifier();
return m_functionCollector->createFunction(functionName, [&]() {
return Whiskers(R"(
function <functionName>(length) -> memPtr {
memPtr := <alloc>(<allocSize>(length))
<?dynamic>
mstore(memPtr, length)
</dynamic>
}
)")
("functionName", functionName)
("alloc", allocationFunction())
("allocSize", arrayAllocationSizeFunction(_type))
("dynamic", _type.isDynamicallySized())
.render();
});
}
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string YulUtilFunctions::conversionFunction(Type const& _from, Type const& _to)
{
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if (_from.sizeOnStack() != 1 || _to.sizeOnStack() != 1)
return conversionFunctionSpecial(_from, _to);
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string functionName =
"convert_" +
_from.identifier() +
"_to_" +
_to.identifier();
return m_functionCollector->createFunction(functionName, [&]() {
Whiskers templ(R"(
function <functionName>(value) -> converted {
<body>
}
)");
templ("functionName", functionName);
string body;
auto toCategory = _to.category();
auto fromCategory = _from.category();
switch (fromCategory)
{
case Type::Category::Address:
body =
Whiskers("converted := <convert>(value)")
("convert", conversionFunction(IntegerType(160), _to))
.render();
break;
case Type::Category::Integer:
case Type::Category::RationalNumber:
case Type::Category::Contract:
{
if (RationalNumberType const* rational = dynamic_cast<RationalNumberType const*>(&_from))
solUnimplementedAssert(!rational->isFractional(), "Not yet implemented - FixedPointType.");
if (toCategory == Type::Category::FixedBytes)
{
solAssert(
fromCategory == Type::Category::Integer || fromCategory == Type::Category::RationalNumber,
"Invalid conversion to FixedBytesType requested."
);
FixedBytesType const& toBytesType = dynamic_cast<FixedBytesType const&>(_to);
body =
Whiskers("converted := <shiftLeft>(<clean>(value))")
("shiftLeft", shiftLeftFunction(256 - toBytesType.numBytes() * 8))
("clean", cleanupFunction(_from))
.render();
}
else if (toCategory == Type::Category::Enum)
{
solAssert(_from.mobileType(), "");
body =
Whiskers("converted := <cleanEnum>(<cleanInt>(value))")
("cleanEnum", cleanupFunction(_to))
// "mobileType()" returns integer type for rational
("cleanInt", cleanupFunction(*_from.mobileType()))
.render();
}
else if (toCategory == Type::Category::FixedPoint)
solUnimplemented("Not yet implemented - FixedPointType.");
else if (toCategory == Type::Category::Address)
body =
Whiskers("converted := <convert>(value)")
("convert", conversionFunction(_from, IntegerType(160)))
.render();
else
{
solAssert(
toCategory == Type::Category::Integer ||
toCategory == Type::Category::Contract,
"");
IntegerType const addressType(160);
IntegerType const& to =
toCategory == Type::Category::Integer ?
dynamic_cast<IntegerType const&>(_to) :
addressType;
// Clean according to the "to" type, except if this is
// a widening conversion.
IntegerType const* cleanupType = &to;
if (fromCategory != Type::Category::RationalNumber)
{
IntegerType const& from =
fromCategory == Type::Category::Integer ?
dynamic_cast<IntegerType const&>(_from) :
addressType;
if (to.numBits() > from.numBits())
cleanupType = &from;
}
body =
Whiskers("converted := <cleanInt>(value)")
("cleanInt", cleanupFunction(*cleanupType))
.render();
}
break;
}
case Type::Category::Bool:
{
solAssert(_from == _to, "Invalid conversion for bool.");
body =
Whiskers("converted := <clean>(value)")
("clean", cleanupFunction(_from))
.render();
break;
}
case Type::Category::FixedPoint:
solUnimplemented("Fixed point types not implemented.");
break;
case Type::Category::Array:
{
bool equal = _from == _to;
if (!equal)
{
ArrayType const& from = dynamic_cast<decltype(from)>(_from);
ArrayType const& to = dynamic_cast<decltype(to)>(_to);
if (*from.mobileType() == *to.mobileType())
equal = true;
}
if (equal)
body = "converted := value";
else
solUnimplementedAssert(false, "Array conversion not implemented.");
2019-04-09 13:30:54 +00:00
break;
}
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case Type::Category::Struct:
solUnimplementedAssert(false, "Struct conversion not implemented.");
break;
case Type::Category::FixedBytes:
{
FixedBytesType const& from = dynamic_cast<FixedBytesType const&>(_from);
if (toCategory == Type::Category::Integer)
body =
Whiskers("converted := <convert>(<shift>(value))")
("shift", shiftRightFunction(256 - from.numBytes() * 8))
("convert", conversionFunction(IntegerType(from.numBytes() * 8), _to))
.render();
else if (toCategory == Type::Category::Address)
body =
Whiskers("converted := <convert>(value)")
("convert", conversionFunction(_from, IntegerType(160)))
.render();
else
{
// clear for conversion to longer bytes
solAssert(toCategory == Type::Category::FixedBytes, "Invalid type conversion requested.");
body =
Whiskers("converted := <clean>(value)")
("clean", cleanupFunction(from))
.render();
}
break;
}
case Type::Category::Function:
{
solAssert(false, "Conversion should not be called for function types.");
break;
}
case Type::Category::Enum:
{
solAssert(toCategory == Type::Category::Integer || _from == _to, "");
EnumType const& enumType = dynamic_cast<decltype(enumType)>(_from);
body =
Whiskers("converted := <clean>(value)")
("clean", cleanupFunction(enumType))
.render();
break;
}
case Type::Category::Tuple:
{
solUnimplementedAssert(false, "Tuple conversion not implemented.");
break;
}
default:
solAssert(false, "");
}
solAssert(!body.empty(), _from.canonicalName() + " to " + _to.canonicalName());
templ("body", body);
return templ.render();
});
}
string YulUtilFunctions::cleanupFunction(Type const& _type)
{
string functionName = string("cleanup_") + _type.identifier();
return m_functionCollector->createFunction(functionName, [&]() {
Whiskers templ(R"(
function <functionName>(value) -> cleaned {
<body>
}
)");
templ("functionName", functionName);
switch (_type.category())
{
case Type::Category::Address:
templ("body", "cleaned := " + cleanupFunction(IntegerType(160)) + "(value)");
break;
case Type::Category::Integer:
{
IntegerType const& type = dynamic_cast<IntegerType const&>(_type);
if (type.numBits() == 256)
templ("body", "cleaned := value");
else if (type.isSigned())
templ("body", "cleaned := signextend(" + to_string(type.numBits() / 8 - 1) + ", value)");
else
templ("body", "cleaned := and(value, " + toCompactHexWithPrefix((u256(1) << type.numBits()) - 1) + ")");
break;
}
case Type::Category::RationalNumber:
templ("body", "cleaned := value");
break;
case Type::Category::Bool:
templ("body", "cleaned := iszero(iszero(value))");
break;
case Type::Category::FixedPoint:
solUnimplemented("Fixed point types not implemented.");
break;
case Type::Category::Function:
solAssert(dynamic_cast<FunctionType const&>(_type).kind() == FunctionType::Kind::External, "");
templ("body", "cleaned := " + cleanupFunction(FixedBytesType(24)) + "(value)");
break;
case Type::Category::Array:
case Type::Category::Struct:
case Type::Category::Mapping:
solAssert(_type.dataStoredIn(DataLocation::Storage), "Cleanup requested for non-storage reference type.");
templ("body", "cleaned := value");
break;
case Type::Category::FixedBytes:
{
FixedBytesType const& type = dynamic_cast<FixedBytesType const&>(_type);
if (type.numBytes() == 32)
templ("body", "cleaned := value");
else if (type.numBytes() == 0)
// This is disallowed in the type system.
solAssert(false, "");
else
{
size_t numBits = type.numBytes() * 8;
u256 mask = ((u256(1) << numBits) - 1) << (256 - numBits);
templ("body", "cleaned := and(value, " + toCompactHexWithPrefix(mask) + ")");
}
break;
}
case Type::Category::Contract:
{
AddressType addressType(dynamic_cast<ContractType const&>(_type).isPayable() ?
StateMutability::Payable :
StateMutability::NonPayable
);
templ("body", "cleaned := " + cleanupFunction(addressType) + "(value)");
break;
}
case Type::Category::Enum:
{
// Out of range enums cannot be truncated unambigiously and therefore it should be an error.
templ("body", "cleaned := value " + validatorFunction(_type) + "(value)");
break;
}
case Type::Category::InaccessibleDynamic:
templ("body", "cleaned := 0");
break;
default:
solAssert(false, "Cleanup of type " + _type.identifier() + " requested.");
}
return templ.render();
});
}
string YulUtilFunctions::validatorFunction(Type const& _type, bool _revertOnFailure)
{
string functionName = string("validator_") + (_revertOnFailure ? "revert_" : "assert_") + _type.identifier();
return m_functionCollector->createFunction(functionName, [&]() {
Whiskers templ(R"(
function <functionName>(value) {
if iszero(<condition>) { <failure> }
}
)");
templ("functionName", functionName);
if (_revertOnFailure)
templ("failure", "revert(0, 0)");
else
templ("failure", "invalid()");
switch (_type.category())
{
case Type::Category::Address:
case Type::Category::Integer:
case Type::Category::RationalNumber:
case Type::Category::Bool:
case Type::Category::FixedPoint:
case Type::Category::Function:
case Type::Category::Array:
case Type::Category::Struct:
case Type::Category::Mapping:
case Type::Category::FixedBytes:
case Type::Category::Contract:
{
templ("condition", "eq(value, " + cleanupFunction(_type) + "(value))");
break;
}
case Type::Category::Enum:
{
size_t members = dynamic_cast<EnumType const&>(_type).numberOfMembers();
solAssert(members > 0, "empty enum should have caused a parser error.");
templ("condition", "lt(value, " + to_string(members) + ")");
break;
}
case Type::Category::InaccessibleDynamic:
templ("condition", "1");
break;
default:
solAssert(false, "Validation of type " + _type.identifier() + " requested.");
}
return templ.render();
});
}
2019-05-02 20:33:47 +00:00
string YulUtilFunctions::packedHashFunction(
vector<Type const*> const& _givenTypes,
vector<Type const*> const& _targetTypes
)
{
string functionName = string("packed_hashed_");
for (auto const& t: _givenTypes)
functionName += t->identifier() + "_";
functionName += "_to_";
for (auto const& t: _targetTypes)
functionName += t->identifier() + "_";
size_t sizeOnStack = 0;
for (Type const* t: _givenTypes)
sizeOnStack += t->sizeOnStack();
return m_functionCollector->createFunction(functionName, [&]() {
Whiskers templ(R"(
function <functionName>(<variables>) -> hash {
let pos := mload(<freeMemoryPointer>)
let end := <packedEncode>(pos <comma> <variables>)
hash := keccak256(pos, sub(end, pos))
}
)");
templ("functionName", functionName);
templ("variables", suffixedVariableNameList("var_", 1, 1 + sizeOnStack));
templ("comma", sizeOnStack > 0 ? "," : "");
templ("freeMemoryPointer", to_string(CompilerUtils::freeMemoryPointer));
templ("packedEncode", ABIFunctions(m_evmVersion, m_functionCollector).tupleEncoderPacked(_givenTypes, _targetTypes));
return templ.render();
});
}
string YulUtilFunctions::forwardingRevertFunction()
{
bool forward = m_evmVersion.supportsReturndata();
string functionName = "revert_forward_" + to_string(forward);
return m_functionCollector->createFunction(functionName, [&]() {
if (forward)
return Whiskers(R"(
function <functionName>() {
returndatacopy(0, 0, returndatasize())
revert(0, returndatasize())
}
)")
("functionName", functionName)
.render();
else
return Whiskers(R"(
function <functionName>() {
revert(0, 0)
}
)")
("functionName", functionName)
.render();
});
}
std::string YulUtilFunctions::decrementCheckedFunction(Type const& _type)
{
IntegerType const& type = dynamic_cast<IntegerType const&>(_type);
string const functionName = "decrement_" + _type.identifier();
return m_functionCollector->createFunction(functionName, [&]() {
u256 minintval;
// Smallest admissible value to decrement
if (type.isSigned())
minintval = 0 - (u256(1) << (type.numBits() - 1)) + 1;
else
minintval = 1;
return Whiskers(R"(
function <functionName>(value) -> ret {
if <lt>(value, <minval>) { revert(0,0) }
ret := sub(value, 1)
}
)")
("functionName", functionName)
("minval", toCompactHexWithPrefix(minintval))
("lt", type.isSigned() ? "slt" : "lt")
.render();
});
}
std::string YulUtilFunctions::incrementCheckedFunction(Type const& _type)
{
IntegerType const& type = dynamic_cast<IntegerType const&>(_type);
string const functionName = "increment_" + _type.identifier();
return m_functionCollector->createFunction(functionName, [&]() {
u256 maxintval;
// Biggest admissible value to increment
if (type.isSigned())
maxintval = (u256(1) << (type.numBits() - 1)) - 2;
else
maxintval = (u256(1) << type.numBits()) - 2;
return Whiskers(R"(
function <functionName>(value) -> ret {
if <gt>(value, <maxval>) { revert(0,0) }
ret := add(value, 1)
}
)")
("functionName", functionName)
("maxval", toCompactHexWithPrefix(maxintval))
("gt", type.isSigned() ? "sgt" : "gt")
.render();
});
}
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string YulUtilFunctions::negateNumberCheckedFunction(Type const& _type)
{
IntegerType const& type = dynamic_cast<IntegerType const&>(_type);
solAssert(type.isSigned(), "Expected signed type!");
string const functionName = "negate_" + _type.identifier();
u256 const minintval = 0 - (u256(1) << (type.numBits() - 1)) + 1;
return m_functionCollector->createFunction(functionName, [&]() {
return Whiskers(R"(
function <functionName>(_value) -> ret {
if slt(_value, <minval>) { revert(0,0) }
ret := sub(0, _value)
}
)")
("functionName", functionName)
("minval", toCompactHexWithPrefix(minintval))
.render();
});
}
string YulUtilFunctions::zeroValueFunction(Type const& _type)
{
solUnimplementedAssert(_type.sizeOnStack() == 1, "Stacksize not yet implemented!");
solUnimplementedAssert(_type.isValueType(), "Zero value for non-value types not yet implemented");
string const functionName = "zero_value_for_" + _type.identifier();
return m_functionCollector->createFunction(functionName, [&]() {
return Whiskers(R"(
function <functionName>() -> ret {
<body>
}
)")
("functionName", functionName)
("body", "ret := 0x0")
.render();
});
}
string YulUtilFunctions::storageSetToZeroFunction(Type const& _type)
{
string const functionName = "storage_set_to_zero_" + _type.identifier();
return m_functionCollector->createFunction(functionName, [&]() {
if (_type.isValueType())
return Whiskers(R"(
function <functionName>(slot, offset) {
<store>(slot, offset, <zeroValue>())
}
)")
("functionName", functionName)
("store", updateStorageValueFunction(_type))
("zeroValue", zeroValueFunction(_type))
.render();
else if (_type.category() == Type::Category::Array)
return Whiskers(R"(
function <functionName>(slot, offset) {
<clearArray>(slot)
}
)")
("functionName", functionName)
("clearArray", clearStorageArrayFunction(dynamic_cast<ArrayType const&>(_type)))
.render();
else
solUnimplemented("setToZero for type " + _type.identifier() + " not yet implemented!");
});
}
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string YulUtilFunctions::conversionFunctionSpecial(Type const& _from, Type const& _to)
{
string functionName =
"convert_" +
_from.identifier() +
"_to_" +
_to.identifier();
return m_functionCollector->createFunction(functionName, [&]() {
solUnimplementedAssert(
_from.category() == Type::Category::StringLiteral,
"Type conversion " + _from.toString() + " -> " + _to.toString() + " not yet implemented."
);
string const& data = dynamic_cast<StringLiteralType const&>(_from).value();
if (_to.category() == Type::Category::FixedBytes)
{
unsigned const numBytes = dynamic_cast<FixedBytesType const&>(_to).numBytes();
solAssert(data.size() <= 32, "");
Whiskers templ(R"(
function <functionName>() -> converted {
converted := <data>
}
)");
templ("functionName", functionName);
templ("data", formatNumber(
h256::Arith(h256(data, h256::AlignLeft)) &
(~(u256(-1) >> (8 * numBytes)))
));
return templ.render();
}
else if (_to.category() == Type::Category::Array)
{
auto const& arrayType = dynamic_cast<ArrayType const&>(_to);
solAssert(arrayType.isByteArray(), "");
size_t words = (data.size() + 31) / 32;
size_t storageSize = 32 + words * 32;
Whiskers templ(R"(
function <functionName>() -> converted {
converted := <allocate>(<storageSize>)
mstore(converted, <size>)
<#word>
mstore(add(converted, <offset>), <wordValue>)
</word>
}
)");
templ("functionName", functionName);
templ("allocate", allocationFunction());
templ("storageSize", to_string(storageSize));
templ("size", to_string(data.size()));
vector<map<string, string>> wordParams(words);
for (size_t i = 0; i < words; ++i)
{
wordParams[i]["offset"] = to_string(32 + i * 32);
wordParams[i]["wordValue"] = "0x" + h256(data.substr(32 * i, 32), h256::AlignLeft).hex();
}
templ("word", wordParams);
return templ.render();
}
else
solAssert(
false,
"Invalid conversion from string literal to " + _to.toString() + " requested."
);
});
}
string YulUtilFunctions::readFromMemoryOrCalldata(Type const& _type, bool _fromCalldata)
{
string functionName =
string("read_from_") +
(_fromCalldata ? "calldata" : "memory") +
_type.identifier();
// TODO use ABI functions for handling calldata
if (_fromCalldata)
solAssert(!_type.isDynamicallyEncoded(), "");
return m_functionCollector->createFunction(functionName, [&] {
if (auto refType = dynamic_cast<ReferenceType const*>(&_type))
{
solAssert(refType->sizeOnStack() == 1, "");
solAssert(!_fromCalldata, "");
return Whiskers(R"(
function <functionName>(memPtr) -> value {
value := mload(memPtr)
}
)")
("functionName", functionName)
.render();
}
solAssert(_type.isValueType(), "");
if (auto const* funType = dynamic_cast<FunctionType const*>(&_type))
if (funType->kind() == FunctionType::Kind::External)
return Whiskers(R"(
function <functionName>(memPtr) -> addr, selector {
let combined := <load>(memPtr)
addr, selector := <splitFunction>(combined)
}
)")
("functionName", functionName)
("load", _fromCalldata ? "calldataload" : "mload")
("splitFunction", splitExternalFunctionIdFunction())
.render();
return Whiskers(R"(
function <functionName>(memPtr) -> value {
value := <load>(memPtr)
<?needsValidation>
value := <validate>(value)
</needsValidation>
}
)")
("functionName", functionName)
("load", _fromCalldata ? "calldataload" : "mload")
("needsValidation", _fromCalldata)
("validate", _fromCalldata ? validatorFunction(_type) : "")
.render();
});
}