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CompilerUtils.cpp
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CompilerUtils.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/>.
*/
// SPDX-License-Identifier: GPL-3.0
/**
* @author Christian <c@ethdev.com>
* @date 2014
* Routines used by both the compiler and the expression compiler.
*/
#include <libsolidity/codegen/CompilerUtils.h>
#include <libsolidity/ast/AST.h>
#include <libsolidity/ast/TypeProvider.h>
#include <libsolidity/codegen/ABIFunctions.h>
#include <libsolidity/codegen/ArrayUtils.h>
#include <libsolidity/codegen/LValue.h>
#include <libevmasm/Instruction.h>
#include <libsolutil/Whiskers.h>
using namespace std;
using namespace solidity;
using namespace solidity::evmasm;
using namespace solidity::frontend;
using namespace solidity::langutil;
using solidity::util::Whiskers;
using solidity::util::h256;
using solidity::util::toCompactHexWithPrefix;
unsigned const CompilerUtils::dataStartOffset = 4;
size_t const CompilerUtils::freeMemoryPointer = 64;
size_t const CompilerUtils::zeroPointer = CompilerUtils::freeMemoryPointer + 32;
size_t const CompilerUtils::generalPurposeMemoryStart = CompilerUtils::zeroPointer + 32;
static_assert(CompilerUtils::freeMemoryPointer >= 64, "Free memory pointer must not overlap with scratch area.");
static_assert(CompilerUtils::zeroPointer >= CompilerUtils::freeMemoryPointer + 32, "Zero pointer must not overlap with free memory pointer.");
static_assert(CompilerUtils::generalPurposeMemoryStart >= CompilerUtils::zeroPointer + 32, "General purpose memory must not overlap with zero area.");
void CompilerUtils::initialiseFreeMemoryPointer()
{
size_t reservedMemory = m_context.reservedMemory();
solAssert(bigint(generalPurposeMemoryStart) + bigint(reservedMemory) < bigint(1) << 63, "");
m_context << (u256(generalPurposeMemoryStart) + reservedMemory);
storeFreeMemoryPointer();
}
void CompilerUtils::fetchFreeMemoryPointer()
{
m_context << u256(freeMemoryPointer) << Instruction::MLOAD;
}
void CompilerUtils::storeFreeMemoryPointer()
{
m_context << u256(freeMemoryPointer) << Instruction::MSTORE;
}
void CompilerUtils::allocateMemory()
{
fetchFreeMemoryPointer();
m_context << Instruction::SWAP1 << Instruction::DUP2 << Instruction::ADD;
storeFreeMemoryPointer();
}
void CompilerUtils::allocateMemory(u256 const& size)
{
fetchFreeMemoryPointer();
m_context << Instruction::DUP1 << size << Instruction::ADD;
storeFreeMemoryPointer();
}
void CompilerUtils::toSizeAfterFreeMemoryPointer()
{
fetchFreeMemoryPointer();
m_context << Instruction::DUP1 << Instruction::SWAP2 << Instruction::SUB;
m_context << Instruction::SWAP1;
}
void CompilerUtils::revertWithStringData(Type const& _argumentType)
{
solAssert(_argumentType.isImplicitlyConvertibleTo(*TypeProvider::fromElementaryTypeName("string memory")), "");
fetchFreeMemoryPointer();
m_context << (u256(util::FixedHash<4>::Arith(util::FixedHash<4>(util::keccak256("Error(string)")))) << (256 - 32));
m_context << Instruction::DUP2 << Instruction::MSTORE;
m_context << u256(4) << Instruction::ADD;
// Stack: <string data> <mem pos of encoding start>
abiEncode({&_argumentType}, {TypeProvider::array(DataLocation::Memory, true)});
toSizeAfterFreeMemoryPointer();
m_context << Instruction::REVERT;
}
void CompilerUtils::returnDataToArray()
{
if (m_context.evmVersion().supportsReturndata())
{
m_context << Instruction::RETURNDATASIZE;
m_context.appendInlineAssembly(R"({
switch v case 0 {
v := 0x60
} default {
v := mload(0x40)
mstore(0x40, add(v, and(add(returndatasize(), 0x3f), not(0x1f))))
mstore(v, returndatasize())
returndatacopy(add(v, 0x20), 0, returndatasize())
}
})", {"v"});
}
else
pushZeroPointer();
}
void CompilerUtils::accessCalldataTail(Type const& _type)
{
m_context << Instruction::SWAP1;
m_context.callYulFunction(
m_context.utilFunctions().accessCalldataTailFunction(_type),
2,
_type.isDynamicallySized() ? 2 : 1
);
}
unsigned CompilerUtils::loadFromMemory(
unsigned _offset,
Type const& _type,
bool _fromCalldata,
bool _padToWordBoundaries
)
{
solAssert(_type.category() != Type::Category::Array, "Unable to statically load dynamic type.");
m_context << u256(_offset);
return loadFromMemoryHelper(_type, _fromCalldata, _padToWordBoundaries);
}
void CompilerUtils::loadFromMemoryDynamic(
Type const& _type,
bool _fromCalldata,
bool _padToWordBoundaries,
bool _keepUpdatedMemoryOffset
)
{
if (_keepUpdatedMemoryOffset)
m_context << Instruction::DUP1;
if (auto arrayType = dynamic_cast<ArrayType const*>(&_type))
{
solAssert(!arrayType->isDynamicallySized(), "");
solAssert(!_fromCalldata, "");
solAssert(_padToWordBoundaries, "");
if (_keepUpdatedMemoryOffset)
m_context << arrayType->memoryDataSize() << Instruction::ADD;
}
else
{
unsigned numBytes = loadFromMemoryHelper(_type, _fromCalldata, _padToWordBoundaries);
if (_keepUpdatedMemoryOffset)
{
// update memory counter
moveToStackTop(_type.sizeOnStack());
m_context << u256(numBytes) << Instruction::ADD;
}
}
}
void CompilerUtils::storeInMemory(unsigned _offset)
{
unsigned numBytes = prepareMemoryStore(*TypeProvider::uint256(), true);
if (numBytes > 0)
m_context << u256(_offset) << Instruction::MSTORE;
}
void CompilerUtils::storeInMemoryDynamic(Type const& _type, bool _padToWordBoundaries, bool _cleanup)
{
// process special types (Reference, StringLiteral, Function)
if (auto ref = dynamic_cast<ReferenceType const*>(&_type))
{
solUnimplementedAssert(
ref->location() == DataLocation::Memory,
"Only in-memory reference type can be stored."
);
storeInMemoryDynamic(*TypeProvider::uint256(), _padToWordBoundaries, _cleanup);
}
else if (auto str = dynamic_cast<StringLiteralType const*>(&_type))
{
m_context << Instruction::DUP1;
storeStringData(bytesConstRef(str->value()));
if (_padToWordBoundaries)
m_context << u256(max<size_t>(32, ((str->value().size() + 31) / 32) * 32));
else
m_context << u256(str->value().size());
m_context << Instruction::ADD;
}
else if (
_type.category() == Type::Category::Function &&
dynamic_cast<FunctionType const&>(_type).kind() == FunctionType::Kind::External
)
{
combineExternalFunctionType(true);
m_context << Instruction::DUP2 << Instruction::MSTORE;
m_context << u256(_padToWordBoundaries ? 32 : 24) << Instruction::ADD;
}
else if (_type.isValueType())
{
unsigned numBytes = prepareMemoryStore(_type, _padToWordBoundaries, _cleanup);
m_context << Instruction::DUP2 << Instruction::MSTORE;
m_context << u256(numBytes) << Instruction::ADD;
}
else // Should never happen
{
solAssert(
false,
"Memory store of type " + _type.toString(true) + " not allowed."
);
}
}
void CompilerUtils::abiDecode(TypePointers const& _typeParameters, bool _fromMemory)
{
/// Stack: <source_offset> <length>
if (m_context.experimentalFeatureActive(ExperimentalFeature::ABIEncoderV2))
{
// Use the new Yul-based decoding function
auto stackHeightBefore = m_context.stackHeight();
abiDecodeV2(_typeParameters, _fromMemory);
solAssert(m_context.stackHeight() - stackHeightBefore == sizeOnStack(_typeParameters) - 2, "");
return;
}
//@todo this does not yet support nested dynamic arrays
size_t encodedSize = 0;
for (auto const& t: _typeParameters)
encodedSize += t->decodingType()->calldataHeadSize();
Whiskers templ(R"({
if lt(len, <encodedSize>) { <revertString> }
})");
templ("encodedSize", to_string(encodedSize));
templ("revertString", m_context.revertReasonIfDebug("Calldata too short"));
m_context.appendInlineAssembly(templ.render(), {"len"});
m_context << Instruction::DUP2 << Instruction::ADD;
m_context << Instruction::SWAP1;
/// Stack: <input_end> <source_offset>
// Retain the offset pointer as base_offset, the point from which the data offsets are computed.
m_context << Instruction::DUP1;
for (TypePointer const& parameterType: _typeParameters)
{
// stack: v1 v2 ... v(k-1) input_end base_offset current_offset
TypePointer type = parameterType->decodingType();
solUnimplementedAssert(type, "No decoding type found.");
if (type->category() == Type::Category::Array)
{
auto const& arrayType = dynamic_cast<ArrayType const&>(*type);
solUnimplementedAssert(!arrayType.baseType()->isDynamicallyEncoded(), "Nested arrays not yet implemented.");
if (_fromMemory)
{
solUnimplementedAssert(
arrayType.baseType()->isValueType(),
"Nested memory arrays not yet implemented here."
);
// @todo If base type is an array or struct, it is still calldata-style encoded, so
// we would have to convert it like below.
solAssert(arrayType.location() == DataLocation::Memory, "");
if (arrayType.isDynamicallySized())
{
// compute data pointer
m_context << Instruction::DUP1 << Instruction::MLOAD;
// stack: v1 v2 ... v(k-1) input_end base_offset current_offset data_offset
fetchFreeMemoryPointer();
// stack: v1 v2 ... v(k-1) input_end base_offset current_offset data_offset dstmem
moveIntoStack(4);
// stack: v1 v2 ... v(k-1) dstmem input_end base_offset current_offset data_offset
m_context << Instruction::DUP5;
// stack: v1 v2 ... v(k-1) dstmem input_end base_offset current_offset data_offset dstmem
// Check that the data pointer is valid and that length times
// item size is still inside the range.
Whiskers templ(R"({
if gt(ptr, 0x100000000) { <revertStringPointer> }
ptr := add(ptr, base_offset)
let array_data_start := add(ptr, 0x20)
if gt(array_data_start, input_end) { <revertStringStart> }
let array_length := mload(ptr)
if or(
gt(array_length, 0x100000000),
gt(add(array_data_start, mul(array_length, <item_size>)), input_end)
) { <revertStringLength> }
mstore(dst, array_length)
dst := add(dst, 0x20)
})");
templ("item_size", to_string(arrayType.calldataStride()));
// TODO add test
templ("revertStringPointer", m_context.revertReasonIfDebug("ABI memory decoding: invalid data pointer"));
templ("revertStringStart", m_context.revertReasonIfDebug("ABI memory decoding: invalid data start"));
templ("revertStringLength", m_context.revertReasonIfDebug("ABI memory decoding: invalid data length"));
m_context.appendInlineAssembly(templ.render(), {"input_end", "base_offset", "offset", "ptr", "dst"});
// stack: v1 v2 ... v(k-1) dstmem input_end base_offset current_offset data_ptr dstdata
m_context << Instruction::SWAP1;
// stack: v1 v2 ... v(k-1) dstmem input_end base_offset current_offset dstdata data_ptr
ArrayUtils(m_context).copyArrayToMemory(arrayType, true);
// stack: v1 v2 ... v(k-1) dstmem input_end base_offset current_offset mem_end
storeFreeMemoryPointer();
m_context << u256(0x20) << Instruction::ADD;
}
else
{
// Size has already been checked for this one.
moveIntoStack(2);
m_context << Instruction::DUP3;
m_context << u256(arrayType.calldataHeadSize()) << Instruction::ADD;
}
}
else
{
// first load from calldata and potentially convert to memory if arrayType is memory
TypePointer calldataType = TypeProvider::withLocation(&arrayType, DataLocation::CallData, false);
if (calldataType->isDynamicallySized())
{
// put on stack: data_pointer length
loadFromMemoryDynamic(*TypeProvider::uint256(), !_fromMemory);
m_context << Instruction::SWAP1;
// stack: input_end base_offset next_pointer data_offset
m_context.appendInlineAssembly(Whiskers(R"({
if gt(data_offset, 0x100000000) { <revertString> }
})")
// TODO add test
("revertString", m_context.revertReasonIfDebug("ABI calldata decoding: invalid data offset"))
.render(), {"data_offset"});
m_context << Instruction::DUP3 << Instruction::ADD;
// stack: input_end base_offset next_pointer array_head_ptr
m_context.appendInlineAssembly(Whiskers(R"({
if gt(add(array_head_ptr, 0x20), input_end) { <revertString> }
})")
("revertString", m_context.revertReasonIfDebug("ABI calldata decoding: invalid head pointer"))
.render(), {"input_end", "base_offset", "next_ptr", "array_head_ptr"});
// retrieve length
loadFromMemoryDynamic(*TypeProvider::uint256(), !_fromMemory, true);
// stack: input_end base_offset next_pointer array_length data_pointer
m_context << Instruction::SWAP2;
// stack: input_end base_offset data_pointer array_length next_pointer
m_context.appendInlineAssembly(Whiskers(R"({
if or(
gt(array_length, 0x100000000),
gt(add(data_ptr, mul(array_length, )" + to_string(arrayType.calldataStride()) + R"()), input_end)
) { <revertString> }
})")
("revertString", m_context.revertReasonIfDebug("ABI calldata decoding: invalid data pointer"))
.render(), {"input_end", "base_offset", "data_ptr", "array_length", "next_ptr"});
}
else
{
// size has already been checked
// stack: input_end base_offset data_offset
m_context << Instruction::DUP1;
m_context << u256(calldataType->calldataHeadSize()) << Instruction::ADD;
}
if (arrayType.location() == DataLocation::Memory)
{
// stack: input_end base_offset calldata_ref [length] next_calldata
// copy to memory
// move calldata type up again
moveIntoStack(calldataType->sizeOnStack());
convertType(*calldataType, arrayType, false, false, true);
// fetch next pointer again
moveToStackTop(arrayType.sizeOnStack());
}
// move input_end up
// stack: input_end base_offset calldata_ref [length] next_calldata
moveToStackTop(2 + arrayType.sizeOnStack());
m_context << Instruction::SWAP1;
// stack: base_offset calldata_ref [length] input_end next_calldata
moveToStackTop(2 + arrayType.sizeOnStack());
m_context << Instruction::SWAP1;
// stack: calldata_ref [length] input_end base_offset next_calldata
}
}
else
{
solAssert(!type->isDynamicallyEncoded(), "Unknown dynamically sized type: " + type->toString());
loadFromMemoryDynamic(*type, !_fromMemory, true);
// stack: v1 v2 ... v(k-1) input_end base_offset v(k) mem_offset
moveToStackTop(1, type->sizeOnStack());
moveIntoStack(3, type->sizeOnStack());
}
// stack: v1 v2 ... v(k-1) v(k) input_end base_offset next_offset
}
popStackSlots(3);
}
void CompilerUtils::encodeToMemory(
TypePointers const& _givenTypes,
TypePointers const& _targetTypes,
bool _padToWordBoundaries,
bool _copyDynamicDataInPlace,
bool _encodeAsLibraryTypes
)
{
// stack: <v1> <v2> ... <vn> <mem>
bool const encoderV2 = m_context.experimentalFeatureActive(ExperimentalFeature::ABIEncoderV2);
TypePointers targetTypes = _targetTypes.empty() ? _givenTypes : _targetTypes;
solAssert(targetTypes.size() == _givenTypes.size(), "");
for (TypePointer& t: targetTypes)
{
TypePointer tEncoding = t->fullEncodingType(_encodeAsLibraryTypes, encoderV2, !_padToWordBoundaries);
solUnimplementedAssert(tEncoding, "Encoding type \"" + t->toString() + "\" not yet implemented.");
t = std::move(tEncoding);
}
if (_givenTypes.empty())
return;
if (encoderV2)
{
// Use the new Yul-based encoding function
solAssert(
_padToWordBoundaries != _copyDynamicDataInPlace,
"Non-padded and in-place encoding can only be combined."
);
auto stackHeightBefore = m_context.stackHeight();
abiEncodeV2(_givenTypes, targetTypes, _encodeAsLibraryTypes, _padToWordBoundaries);
solAssert(stackHeightBefore - m_context.stackHeight() == sizeOnStack(_givenTypes), "");
return;
}
// Stack during operation:
// <v1> <v2> ... <vn> <mem_start> <dyn_head_1> ... <dyn_head_r> <end_of_mem>
// The values dyn_head_n are added during the first loop and they point to the head part
// of the nth dynamic parameter, which is filled once the dynamic parts are processed.
// store memory start pointer
m_context << Instruction::DUP1;
unsigned argSize = CompilerUtils::sizeOnStack(_givenTypes);
unsigned stackPos = 0; // advances through the argument values
unsigned dynPointers = 0; // number of dynamic head pointers on the stack
for (size_t i = 0; i < _givenTypes.size(); ++i)
{
TypePointer targetType = targetTypes[i];
solAssert(!!targetType, "Externalable type expected.");
if (targetType->isDynamicallySized() && !_copyDynamicDataInPlace)
{
// leave end_of_mem as dyn head pointer
m_context << Instruction::DUP1 << u256(32) << Instruction::ADD;
dynPointers++;
assertThrow(
(argSize + dynPointers) < 16,
StackTooDeepError,
"Stack too deep, try using fewer variables."
);
}
else
{
bool needCleanup = true;
copyToStackTop(argSize - stackPos + dynPointers + 2, _givenTypes[i]->sizeOnStack());
solAssert(!!targetType, "Externalable type expected.");
TypePointer type = targetType;
if (_givenTypes[i]->dataStoredIn(DataLocation::Storage) && targetType->isValueType())
{
// special case: convert storage reference type to value type - this is only
// possible for library calls where we just forward the storage reference
solAssert(_encodeAsLibraryTypes, "");
solAssert(_givenTypes[i]->sizeOnStack() == 1, "");
}
else if (
_givenTypes[i]->dataStoredIn(DataLocation::Storage) ||
_givenTypes[i]->dataStoredIn(DataLocation::CallData) ||
_givenTypes[i]->category() == Type::Category::StringLiteral ||
_givenTypes[i]->category() == Type::Category::Function
)
type = _givenTypes[i]; // delay conversion
else
{
convertType(*_givenTypes[i], *targetType, true);
needCleanup = false;
}
if (auto arrayType = dynamic_cast<ArrayType const*>(type))
ArrayUtils(m_context).copyArrayToMemory(*arrayType, _padToWordBoundaries);
else if (auto arraySliceType = dynamic_cast<ArraySliceType const*>(type))
{
solAssert(
arraySliceType->dataStoredIn(DataLocation::CallData) &&
arraySliceType->isDynamicallySized() &&
!arraySliceType->arrayType().baseType()->isDynamicallyEncoded(),
""
);
ArrayUtils(m_context).copyArrayToMemory(arraySliceType->arrayType(), _padToWordBoundaries);
}
else
storeInMemoryDynamic(*type, _padToWordBoundaries, needCleanup);
}
stackPos += _givenTypes[i]->sizeOnStack();
}
// now copy the dynamic part
// Stack: <v1> <v2> ... <vn> <mem_start> <dyn_head_1> ... <dyn_head_r> <end_of_mem>
stackPos = 0;
unsigned thisDynPointer = 0;
for (size_t i = 0; i < _givenTypes.size(); ++i)
{
TypePointer targetType = targetTypes[i];
solAssert(!!targetType, "Externalable type expected.");
if (targetType->isDynamicallySized() && !_copyDynamicDataInPlace)
{
// copy tail pointer (=mem_end - mem_start) to memory
assertThrow(
(2 + dynPointers) <= 16,
StackTooDeepError,
"Stack too deep(" + to_string(2 + dynPointers) + "), try using fewer variables."
);
m_context << dupInstruction(2 + dynPointers) << Instruction::DUP2;
m_context << Instruction::SUB;
m_context << dupInstruction(2 + dynPointers - thisDynPointer);
m_context << Instruction::MSTORE;
// stack: ... <end_of_mem>
if (_givenTypes[i]->category() == Type::Category::StringLiteral)
{
auto const& strType = dynamic_cast<StringLiteralType const&>(*_givenTypes[i]);
m_context << u256(strType.value().size());
storeInMemoryDynamic(*TypeProvider::uint256(), true);
// stack: ... <end_of_mem'>
storeInMemoryDynamic(strType, _padToWordBoundaries);
}
else
{
ArrayType const* arrayType = nullptr;
switch (_givenTypes[i]->category())
{
case Type::Category::Array:
arrayType = dynamic_cast<ArrayType const*>(_givenTypes[i]);
break;
case Type::Category::ArraySlice:
arrayType = &dynamic_cast<ArraySliceType const*>(_givenTypes[i])->arrayType();
solAssert(
arrayType->isDynamicallySized() &&
arrayType->dataStoredIn(DataLocation::CallData) &&
!arrayType->baseType()->isDynamicallyEncoded(),
""
);
break;
default:
solAssert(false, "Unknown dynamic type.");
break;
}
// now copy the array
copyToStackTop(argSize - stackPos + dynPointers + 2, arrayType->sizeOnStack());
// stack: ... <end_of_mem> <value...>
// copy length to memory
m_context << dupInstruction(1 + arrayType->sizeOnStack());
ArrayUtils(m_context).retrieveLength(*arrayType, 1);
// stack: ... <end_of_mem> <value...> <end_of_mem'> <length>
storeInMemoryDynamic(*TypeProvider::uint256(), true);
// stack: ... <end_of_mem> <value...> <end_of_mem''>
// copy the new memory pointer
m_context << swapInstruction(arrayType->sizeOnStack() + 1) << Instruction::POP;
// stack: ... <end_of_mem''> <value...>
// copy data part
ArrayUtils(m_context).copyArrayToMemory(*arrayType, _padToWordBoundaries);
// stack: ... <end_of_mem'''>
}
thisDynPointer++;
}
stackPos += _givenTypes[i]->sizeOnStack();
}
// remove unneeded stack elements (and retain memory pointer)
m_context << swapInstruction(argSize + dynPointers + 1);
popStackSlots(argSize + dynPointers + 1);
}
void CompilerUtils::abiEncodeV2(
TypePointers const& _givenTypes,
TypePointers const& _targetTypes,
bool _encodeAsLibraryTypes,
bool _padToWordBoundaries
)
{
if (!_padToWordBoundaries)
solAssert(!_encodeAsLibraryTypes, "Library calls cannot be packed.");
// stack: <$value0> <$value1> ... <$value(n-1)> <$headStart>
string encoderName =
_padToWordBoundaries ?
m_context.abiFunctions().tupleEncoderReversed(_givenTypes, _targetTypes, _encodeAsLibraryTypes) :
m_context.abiFunctions().tupleEncoderPackedReversed(_givenTypes, _targetTypes);
m_context.callYulFunction(encoderName, sizeOnStack(_givenTypes) + 1, 1);
}
void CompilerUtils::abiDecodeV2(TypePointers const& _parameterTypes, bool _fromMemory)
{
// stack: <source_offset> <length> [stack top]
m_context << Instruction::DUP2 << Instruction::ADD;
m_context << Instruction::SWAP1;
// stack: <end> <start>
string decoderName = m_context.abiFunctions().tupleDecoder(_parameterTypes, _fromMemory);
m_context.callYulFunction(decoderName, 2, sizeOnStack(_parameterTypes));
}
void CompilerUtils::zeroInitialiseMemoryArray(ArrayType const& _type)
{
if (_type.baseType()->hasSimpleZeroValueInMemory())
{
solAssert(_type.baseType()->isValueType(), "");
Whiskers templ(R"({
let size := mul(length, <element_size>)
// cheap way of zero-initializing a memory range
calldatacopy(memptr, calldatasize(), size)
memptr := add(memptr, size)
})");
templ("element_size", to_string(_type.memoryStride()));
m_context.appendInlineAssembly(templ.render(), {"length", "memptr"});
}
else
{
auto repeat = m_context.newTag();
m_context << repeat;
pushZeroValue(*_type.baseType());
storeInMemoryDynamic(*_type.baseType());
m_context << Instruction::SWAP1 << u256(1) << Instruction::SWAP1;
m_context << Instruction::SUB << Instruction::SWAP1;
m_context << Instruction::DUP2;
m_context.appendConditionalJumpTo(repeat);
}
m_context << Instruction::SWAP1 << Instruction::POP;
}
void CompilerUtils::memoryCopy32()
{
// Stack here: size target source
m_context.appendInlineAssembly(R"(
{
for { let i := 0 } lt(i, len) { i := add(i, 32) } {
mstore(add(dst, i), mload(add(src, i)))
}
}
)",
{ "len", "dst", "src" }
);
m_context << Instruction::POP << Instruction::POP << Instruction::POP;
}
void CompilerUtils::memoryCopy()
{
// Stack here: size target source
m_context.appendInlineAssembly(R"(
{
// copy 32 bytes at once
for
{}
iszero(lt(len, 32))
{
dst := add(dst, 32)
src := add(src, 32)
len := sub(len, 32)
}
{ mstore(dst, mload(src)) }
// copy the remainder (0 < len < 32)
let mask := sub(exp(256, sub(32, len)), 1)
let srcpart := and(mload(src), not(mask))
let dstpart := and(mload(dst), mask)
mstore(dst, or(srcpart, dstpart))
}
)",
{ "len", "dst", "src" }
);
m_context << Instruction::POP << Instruction::POP << Instruction::POP;
}
void CompilerUtils::splitExternalFunctionType(bool _leftAligned)
{
// We have to split the left-aligned <address><function identifier> into two stack slots:
// address (right aligned), function identifier (right aligned)
if (_leftAligned)
{
m_context << Instruction::DUP1;
rightShiftNumberOnStack(64 + 32);
// <input> <address>
m_context << Instruction::SWAP1;
rightShiftNumberOnStack(64);
}
else
{
m_context << Instruction::DUP1;
rightShiftNumberOnStack(32);
m_context << ((u256(1) << 160) - 1) << Instruction::AND << Instruction::SWAP1;
}
m_context << u256(0xffffffffUL) << Instruction::AND;
}
void CompilerUtils::combineExternalFunctionType(bool _leftAligned)
{
// <address> <function_id>
m_context << u256(0xffffffffUL) << Instruction::AND << Instruction::SWAP1;
if (!_leftAligned)
m_context << ((u256(1) << 160) - 1) << Instruction::AND;
leftShiftNumberOnStack(32);
m_context << Instruction::OR;
if (_leftAligned)
leftShiftNumberOnStack(64);
}
void CompilerUtils::pushCombinedFunctionEntryLabel(Declaration const& _function, bool _runtimeOnly)
{
m_context << m_context.functionEntryLabel(_function).pushTag();
// If there is a runtime context, we have to merge both labels into the same
// stack slot in case we store it in storage.
if (CompilerContext* rtc = m_context.runtimeContext())
{
leftShiftNumberOnStack(32);
if (_runtimeOnly)
m_context <<
rtc->functionEntryLabel(_function).toSubAssemblyTag(m_context.runtimeSub()) <<
Instruction::OR;
}
}
void CompilerUtils::convertType(
Type const& _typeOnStack,
Type const& _targetType,
bool _cleanupNeeded,
bool _chopSignBits,
bool _asPartOfArgumentDecoding
)
{
// For a type extension, we need to remove all higher-order bits that we might have ignored in
// previous operations.
// @todo: store in the AST whether the operand might have "dirty" higher order bits
if (_typeOnStack == _targetType && !_cleanupNeeded)
return;
Type::Category stackTypeCategory = _typeOnStack.category();
Type::Category targetTypeCategory = _targetType.category();
if (auto contrType = dynamic_cast<ContractType const*>(&_typeOnStack))
solAssert(!contrType->isSuper(), "Cannot convert magic variable \"super\"");
bool enumOverflowCheckPending = (targetTypeCategory == Type::Category::Enum || stackTypeCategory == Type::Category::Enum);
bool chopSignBitsPending = _chopSignBits && targetTypeCategory == Type::Category::Integer;
if (chopSignBitsPending)
{
IntegerType const& targetIntegerType = dynamic_cast<IntegerType const&>(_targetType);
chopSignBitsPending = targetIntegerType.isSigned();
}
if (targetTypeCategory == Type::Category::FixedPoint)
solUnimplemented("Not yet implemented - FixedPointType.");
switch (stackTypeCategory)
{
case Type::Category::FixedBytes:
{
FixedBytesType const& typeOnStack = dynamic_cast<FixedBytesType const&>(_typeOnStack);
if (targetTypeCategory == Type::Category::Integer)
{
// conversion from bytes to integer. no need to clean the high bit
// only to shift right because of opposite alignment
IntegerType const& targetIntegerType = dynamic_cast<IntegerType const&>(_targetType);
rightShiftNumberOnStack(256 - typeOnStack.numBytes() * 8);
if (targetIntegerType.numBits() < typeOnStack.numBytes() * 8)
convertType(IntegerType(typeOnStack.numBytes() * 8), _targetType, _cleanupNeeded);
}
else if (targetTypeCategory == Type::Category::Address)
{
solAssert(typeOnStack.numBytes() * 8 == 160, "");
rightShiftNumberOnStack(256 - 160);
}
else
{
// clear for conversion to longer bytes
solAssert(targetTypeCategory == Type::Category::FixedBytes, "Invalid type conversion requested.");
FixedBytesType const& targetType = dynamic_cast<FixedBytesType const&>(_targetType);
if (typeOnStack.numBytes() == 0 || targetType.numBytes() == 0)
m_context << Instruction::POP << u256(0);
else if (targetType.numBytes() > typeOnStack.numBytes() || _cleanupNeeded)
{
unsigned bytes = min(typeOnStack.numBytes(), targetType.numBytes());
m_context << ((u256(1) << (256 - bytes * 8)) - 1);
m_context << Instruction::NOT << Instruction::AND;
}
}
break;
}
case Type::Category::Enum:
solAssert(_targetType == _typeOnStack || targetTypeCategory == Type::Category::Integer, "");
if (enumOverflowCheckPending)
{
EnumType const& enumType = dynamic_cast<decltype(enumType)>(_typeOnStack);
solAssert(enumType.numberOfMembers() > 0, "empty enum should have caused a parser error.");
m_context << u256(enumType.numberOfMembers() - 1) << Instruction::DUP2 << Instruction::GT;
if (_asPartOfArgumentDecoding)
m_context.appendConditionalRevert(false, "Enum out of range");
else
m_context.appendConditionalInvalid();
enumOverflowCheckPending = false;
}
break;
case Type::Category::FixedPoint:
solUnimplemented("Not yet implemented - FixedPointType.");
case Type::Category::Address:
case Type::Category::Integer:
case Type::Category::Contract:
case Type::Category::RationalNumber:
if (targetTypeCategory == Type::Category::FixedBytes)
{
solAssert(
stackTypeCategory == Type::Category::Address ||
stackTypeCategory == Type::Category::Integer ||
stackTypeCategory == Type::Category::RationalNumber,
"Invalid conversion to FixedBytesType requested."
);
// conversion from bytes to string. no need to clean the high bit
// only to shift left because of opposite alignment
FixedBytesType const& targetBytesType = dynamic_cast<FixedBytesType const&>(_targetType);
if (auto typeOnStack = dynamic_cast<IntegerType const*>(&_typeOnStack))
{
if (targetBytesType.numBytes() * 8 > typeOnStack->numBits())
cleanHigherOrderBits(*typeOnStack);
}
else if (stackTypeCategory == Type::Category::Address)
solAssert(targetBytesType.numBytes() * 8 == 160, "");
leftShiftNumberOnStack(256 - targetBytesType.numBytes() * 8);
}
else if (targetTypeCategory == Type::Category::Enum)
{
solAssert(stackTypeCategory != Type::Category::Address, "Invalid conversion to EnumType requested.");
solAssert(_typeOnStack.mobileType(), "");
// just clean
convertType(_typeOnStack, *_typeOnStack.mobileType(), true);
EnumType const& enumType = dynamic_cast<decltype(enumType)>(_targetType);
solAssert(enumType.numberOfMembers() > 0, "empty enum should have caused a parser error.");
m_context << u256(enumType.numberOfMembers() - 1) << Instruction::DUP2 << Instruction::GT;
m_context.appendConditionalInvalid();
enumOverflowCheckPending = false;
}
else if (targetTypeCategory == Type::Category::FixedPoint)
{
solAssert(
stackTypeCategory == Type::Category::Integer ||
stackTypeCategory == Type::Category::RationalNumber ||
stackTypeCategory == Type::Category::FixedPoint,
"Invalid conversion to FixedMxNType requested."
);
//shift all integer bits onto the left side of the fixed type
FixedPointType const& targetFixedPointType = dynamic_cast<FixedPointType const&>(_targetType);
if (auto typeOnStack = dynamic_cast<IntegerType const*>(&_typeOnStack))
if (targetFixedPointType.numBits() > typeOnStack->numBits())
cleanHigherOrderBits(*typeOnStack);
solUnimplemented("Not yet implemented - FixedPointType.");
}
else
{
solAssert(
targetTypeCategory == Type::Category::Integer ||
targetTypeCategory == Type::Category::Contract ||
targetTypeCategory == Type::Category::Address,
""
);
IntegerType addressType(160);
IntegerType const& targetType = targetTypeCategory == Type::Category::Integer
? dynamic_cast<IntegerType const&>(_targetType) : addressType;
if (stackTypeCategory == Type::Category::RationalNumber)
{
RationalNumberType const& constType = dynamic_cast<RationalNumberType const&>(_typeOnStack);
// We know that the stack is clean, we only have to clean for a narrowing conversion
// where cleanup is forced.
solUnimplementedAssert(!constType.isFractional(), "Not yet implemented - FixedPointType.");
if (targetType.numBits() < constType.integerType()->numBits() && _cleanupNeeded)
cleanHigherOrderBits(targetType);
}
else
{
IntegerType const& typeOnStack = stackTypeCategory == Type::Category::Integer
? dynamic_cast<IntegerType const&>(_typeOnStack) : addressType;
// Widening: clean up according to source type width
// Non-widening and force: clean up according to target type bits
if (targetType.numBits() > typeOnStack.numBits())
cleanHigherOrderBits(typeOnStack);
else if (_cleanupNeeded)
cleanHigherOrderBits(targetType);
if (chopSignBitsPending)
{
if (targetType.numBits() < 256)
m_context
<< ((u256(1) << targetType.numBits()) - 1)
<< Instruction::AND;
chopSignBitsPending = false;
}
}
}
break;
case Type::Category::StringLiteral:
{
auto const& literalType = dynamic_cast<StringLiteralType const&>(_typeOnStack);
string const& value = literalType.value();
bytesConstRef data(value);
if (targetTypeCategory == Type::Category::FixedBytes)
{
unsigned const numBytes = dynamic_cast<FixedBytesType const&>(_targetType).numBytes();
solAssert(data.size() <= 32, "");
m_context << (h256::Arith(h256(data, h256::AlignLeft)) & (~(u256(-1) >> (8 * numBytes))));
}
else if (targetTypeCategory == Type::Category::Array)
{
auto const& arrayType = dynamic_cast<ArrayType const&>(_targetType);
solAssert(arrayType.isByteArray(), "");
unsigned storageSize = 32 + ((data.size() + 31) / 32) * 32;
allocateMemory(storageSize);
// stack: mempos
m_context << Instruction::DUP1 << u256(data.size());
storeInMemoryDynamic(*TypeProvider::uint256());
// stack: mempos datapos
storeStringData(data);
}
else
solAssert(
false,
"Invalid conversion from string literal to " + _targetType.toString(false) + " requested."
);
break;
}
case Type::Category::Array:
{
solAssert(targetTypeCategory == stackTypeCategory, "");
ArrayType const& typeOnStack = dynamic_cast<ArrayType const&>(_typeOnStack);
ArrayType const& targetType = dynamic_cast<ArrayType const&>(_targetType);
switch (targetType.location())
{
case DataLocation::Storage:
// Other cases are done explicitly in LValue::storeValue, and only possible by assignment.
solAssert(
(targetType.isPointer() || (typeOnStack.isByteArray() && targetType.isByteArray())) &&
typeOnStack.location() == DataLocation::Storage,
"Invalid conversion to storage type."
);
break;
case DataLocation::Memory:
{
// Copy the array to a free position in memory, unless it is already in memory.
if (typeOnStack.location() != DataLocation::Memory)
{
// stack: <source ref> (variably sized)
unsigned stackSize = typeOnStack.sizeOnStack();
ArrayUtils(m_context).retrieveLength(typeOnStack);
// allocate memory
// stack: <source ref> (variably sized) <length>
m_context << Instruction::DUP1;
ArrayUtils(m_context).convertLengthToSize(targetType, true);
// stack: <source ref> (variably sized) <length> <size>
if (targetType.isDynamicallySized())
m_context << u256(0x20) << Instruction::ADD;
allocateMemory();
// stack: <source ref> (variably sized) <length> <mem start>
m_context << Instruction::DUP1;
moveIntoStack(2 + stackSize);
if (targetType.isDynamicallySized())
{
m_context << Instruction::DUP2;
storeInMemoryDynamic(*TypeProvider::uint256());
}
// stack: <mem start> <source ref> (variably sized) <length> <mem data pos>
if (targetType.baseType()->isValueType())
{
copyToStackTop(2 + stackSize, stackSize);
ArrayUtils(m_context).copyArrayToMemory(typeOnStack);
}
else
{
if (auto baseType = dynamic_cast<ArrayType const*>(typeOnStack.baseType()))
solUnimplementedAssert(
typeOnStack.location() != DataLocation::CallData ||
!typeOnStack.isDynamicallyEncoded() ||
!baseType->isDynamicallySized(),
"Copying nested dynamic calldata arrays to memory is not implemented in the old code generator."
);
m_context << u256(0) << Instruction::SWAP1;
// stack: <mem start> <source ref> (variably sized) <length> <counter> <mem data pos>
auto repeat = m_context.newTag();
m_context << repeat;
m_context << Instruction::DUP3 << Instruction::DUP3;