solidity/libyul/backends/evm/EVMDialect.cpp
2020-09-17 22:13:27 +02:00

424 lines
14 KiB
C++

/*
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
/**
* Yul dialects for EVM.
*/
#include <libyul/backends/evm/EVMDialect.h>
#include <libyul/AsmAnalysisInfo.h>
#include <libyul/AsmData.h>
#include <libyul/Object.h>
#include <libyul/Exceptions.h>
#include <libyul/AsmParser.h>
#include <libyul/backends/evm/AbstractAssembly.h>
#include <libevmasm/SemanticInformation.h>
#include <libevmasm/Instruction.h>
#include <liblangutil/Exceptions.h>
#include <boost/range/adaptor/reversed.hpp>
using namespace std;
using namespace solidity;
using namespace solidity::yul;
using namespace solidity::util;
namespace
{
void visitArguments(
AbstractAssembly& _assembly,
FunctionCall const& _call,
function<void(Expression const&)> _visitExpression
)
{
for (auto const& arg: _call.arguments | boost::adaptors::reversed)
_visitExpression(arg);
_assembly.setSourceLocation(_call.location);
}
pair<YulString, BuiltinFunctionForEVM> createEVMFunction(
string const& _name,
evmasm::Instruction _instruction
)
{
evmasm::InstructionInfo info = evmasm::instructionInfo(_instruction);
BuiltinFunctionForEVM f;
f.name = YulString{_name};
f.parameters.resize(static_cast<size_t>(info.args));
f.returns.resize(static_cast<size_t>(info.ret));
f.sideEffects = EVMDialect::sideEffectsOfInstruction(_instruction);
f.controlFlowSideEffects.terminates = evmasm::SemanticInformation::terminatesControlFlow(_instruction);
f.controlFlowSideEffects.reverts = evmasm::SemanticInformation::reverts(_instruction);
f.isMSize = _instruction == evmasm::Instruction::MSIZE;
f.literalArguments.clear();
f.instruction = _instruction;
f.generateCode = [_instruction](
FunctionCall const& _call,
AbstractAssembly& _assembly,
BuiltinContext&,
std::function<void(Expression const&)> _visitExpression
) {
visitArguments(_assembly, _call, _visitExpression);
_assembly.appendInstruction(_instruction);
};
return {f.name, move(f)};
}
pair<YulString, BuiltinFunctionForEVM> createFunction(
string _name,
size_t _params,
size_t _returns,
SideEffects _sideEffects,
vector<optional<LiteralKind>> _literalArguments,
std::function<void(FunctionCall const&, AbstractAssembly&, BuiltinContext&, std::function<void(Expression const&)>)> _generateCode
)
{
yulAssert(_literalArguments.size() == _params || _literalArguments.empty(), "");
YulString name{std::move(_name)};
BuiltinFunctionForEVM f;
f.name = name;
f.parameters.resize(_params);
f.returns.resize(_returns);
f.sideEffects = std::move(_sideEffects);
f.literalArguments = std::move(_literalArguments);
f.isMSize = false;
f.instruction = {};
f.generateCode = std::move(_generateCode);
return {name, f};
}
map<YulString, BuiltinFunctionForEVM> createBuiltins(langutil::EVMVersion _evmVersion, bool _objectAccess)
{
map<YulString, BuiltinFunctionForEVM> builtins;
for (auto const& instr: evmasm::c_instructions)
{
string name = instr.first;
transform(name.begin(), name.end(), name.begin(), [](unsigned char _c) { return tolower(_c); });
auto const opcode = instr.second;
if (
!evmasm::isDupInstruction(opcode) &&
!evmasm::isSwapInstruction(opcode) &&
!evmasm::isPushInstruction(opcode) &&
opcode != evmasm::Instruction::JUMP &&
opcode != evmasm::Instruction::JUMPI &&
opcode != evmasm::Instruction::JUMPDEST &&
_evmVersion.hasOpcode(opcode)
)
builtins.emplace(createEVMFunction(name, opcode));
}
if (_objectAccess)
{
builtins.emplace(createFunction("linkersymbol", 1, 1, SideEffects{}, {LiteralKind::String}, [](
FunctionCall const& _call,
AbstractAssembly& _assembly,
BuiltinContext&,
function<void(Expression const&)>
) {
yulAssert(_call.arguments.size() == 1, "");
Expression const& arg = _call.arguments.front();
_assembly.appendLinkerSymbol(std::get<Literal>(arg).value.str());
}));
builtins.emplace(createFunction(
"memoryguard",
1,
1,
SideEffects{},
{LiteralKind::Number},
[](
FunctionCall const& _call,
AbstractAssembly& _assembly,
BuiltinContext&,
function<void(Expression const&)> _visitExpression
) {
visitArguments(_assembly, _call, _visitExpression);
})
);
builtins.emplace(createFunction("datasize", 1, 1, SideEffects{}, {LiteralKind::String}, [](
FunctionCall const& _call,
AbstractAssembly& _assembly,
BuiltinContext& _context,
std::function<void(Expression const&)> const&
) {
yulAssert(_context.currentObject, "No object available.");
yulAssert(_call.arguments.size() == 1, "");
Expression const& arg = _call.arguments.front();
YulString dataName = std::get<Literal>(arg).value;
if (_context.currentObject->name == dataName)
_assembly.appendAssemblySize();
else
{
vector<size_t> subIdPath =
_context.subIDs.count(dataName) == 0 ?
_context.currentObject->pathToSubObject(dataName) :
vector<size_t>{_context.subIDs.at(dataName)};
yulAssert(!subIdPath.empty(), "Could not find assembly object <" + dataName.str() + ">.");
_assembly.appendDataSize(subIdPath);
}
}));
builtins.emplace(createFunction("dataoffset", 1, 1, SideEffects{}, {LiteralKind::String}, [](
FunctionCall const& _call,
AbstractAssembly& _assembly,
BuiltinContext& _context,
std::function<void(Expression const&)> const&
) {
yulAssert(_context.currentObject, "No object available.");
yulAssert(_call.arguments.size() == 1, "");
Expression const& arg = _call.arguments.front();
YulString dataName = std::get<Literal>(arg).value;
if (_context.currentObject->name == dataName)
_assembly.appendConstant(0);
else
{
vector<size_t> subIdPath =
_context.subIDs.count(dataName) == 0 ?
_context.currentObject->pathToSubObject(dataName) :
vector<size_t>{_context.subIDs.at(dataName)};
yulAssert(!subIdPath.empty(), "Could not find assembly object <" + dataName.str() + ">.");
_assembly.appendDataOffset(subIdPath);
}
}));
builtins.emplace(createFunction(
"datacopy",
3,
0,
SideEffects{false, true, false, false, true, SideEffects::None, SideEffects::None, SideEffects::Write},
{},
[](
FunctionCall const& _call,
AbstractAssembly& _assembly,
BuiltinContext&,
std::function<void(Expression const&)> _visitExpression
) {
visitArguments(_assembly, _call, _visitExpression);
_assembly.appendInstruction(evmasm::Instruction::CODECOPY);
}
));
builtins.emplace(createFunction(
"setimmutable",
2,
0,
SideEffects{false, false, false, false, true, SideEffects::None, SideEffects::None, SideEffects::Write},
{LiteralKind::String, std::nullopt},
[](
FunctionCall const& _call,
AbstractAssembly& _assembly,
BuiltinContext&,
std::function<void(Expression const&)> _visitExpression
) {
yulAssert(_call.arguments.size() == 2, "");
_visitExpression(_call.arguments[1]);
_assembly.setSourceLocation(_call.location);
YulString identifier = std::get<Literal>(_call.arguments.front()).value;
_assembly.appendImmutableAssignment(identifier.str());
}
));
builtins.emplace(createFunction(
"loadimmutable",
1,
1,
SideEffects{},
{LiteralKind::String},
[](
FunctionCall const& _call,
AbstractAssembly& _assembly,
BuiltinContext&,
std::function<void(Expression const&)>
) {
yulAssert(_call.arguments.size() == 1, "");
_assembly.appendImmutable(std::get<Literal>(_call.arguments.front()).value.str());
}
));
}
return builtins;
}
}
EVMDialect::EVMDialect(langutil::EVMVersion _evmVersion, bool _objectAccess):
m_objectAccess(_objectAccess),
m_evmVersion(_evmVersion),
m_functions(createBuiltins(_evmVersion, _objectAccess))
{
}
BuiltinFunctionForEVM const* EVMDialect::builtin(YulString _name) const
{
auto it = m_functions.find(_name);
if (it != m_functions.end())
return &it->second;
else
return nullptr;
}
EVMDialect const& EVMDialect::strictAssemblyForEVM(langutil::EVMVersion _version)
{
static map<langutil::EVMVersion, unique_ptr<EVMDialect const>> dialects;
static YulStringRepository::ResetCallback callback{[&] { dialects.clear(); }};
if (!dialects[_version])
dialects[_version] = make_unique<EVMDialect>(_version, false);
return *dialects[_version];
}
EVMDialect const& EVMDialect::strictAssemblyForEVMObjects(langutil::EVMVersion _version)
{
static map<langutil::EVMVersion, unique_ptr<EVMDialect const>> dialects;
static YulStringRepository::ResetCallback callback{[&] { dialects.clear(); }};
if (!dialects[_version])
dialects[_version] = make_unique<EVMDialect>(_version, true);
return *dialects[_version];
}
SideEffects EVMDialect::sideEffectsOfInstruction(evmasm::Instruction _instruction)
{
auto translate = [](evmasm::SemanticInformation::Effect _e) -> SideEffects::Effect
{
return static_cast<SideEffects::Effect>(_e);
};
return SideEffects{
evmasm::SemanticInformation::movable(_instruction),
evmasm::SemanticInformation::movableApartFromEffects(_instruction),
evmasm::SemanticInformation::canBeRemoved(_instruction),
evmasm::SemanticInformation::canBeRemovedIfNoMSize(_instruction),
true, // cannotLoop
translate(evmasm::SemanticInformation::otherState(_instruction)),
translate(evmasm::SemanticInformation::storage(_instruction)),
translate(evmasm::SemanticInformation::memory(_instruction)),
};
}
EVMDialectTyped::EVMDialectTyped(langutil::EVMVersion _evmVersion, bool _objectAccess):
EVMDialect(_evmVersion, _objectAccess)
{
defaultType = "u256"_yulstring;
boolType = "bool"_yulstring;
types = {defaultType, boolType};
// Set all types to ``defaultType``
for (auto& fun: m_functions)
{
for (auto& p: fun.second.parameters)
p = defaultType;
for (auto& r: fun.second.returns)
r = defaultType;
}
m_functions["lt"_yulstring].returns = {"bool"_yulstring};
m_functions["gt"_yulstring].returns = {"bool"_yulstring};
m_functions["slt"_yulstring].returns = {"bool"_yulstring};
m_functions["sgt"_yulstring].returns = {"bool"_yulstring};
m_functions["eq"_yulstring].returns = {"bool"_yulstring};
// "not" and "bitnot" replace "iszero" and "not"
m_functions["bitnot"_yulstring] = m_functions["not"_yulstring];
m_functions["bitnot"_yulstring].name = "bitnot"_yulstring;
m_functions["not"_yulstring] = m_functions["iszero"_yulstring];
m_functions["not"_yulstring].name = "not"_yulstring;
m_functions["not"_yulstring].returns = {"bool"_yulstring};
m_functions["not"_yulstring].parameters = {"bool"_yulstring};
m_functions.erase("iszero"_yulstring);
m_functions["bitand"_yulstring] = m_functions["and"_yulstring];
m_functions["bitand"_yulstring].name = "bitand"_yulstring;
m_functions["bitor"_yulstring] = m_functions["or"_yulstring];
m_functions["bitor"_yulstring].name = "bitor"_yulstring;
m_functions["bitxor"_yulstring] = m_functions["xor"_yulstring];
m_functions["bitxor"_yulstring].name = "bitxor"_yulstring;
m_functions["and"_yulstring].parameters = {"bool"_yulstring, "bool"_yulstring};
m_functions["and"_yulstring].returns = {"bool"_yulstring};
m_functions["or"_yulstring].parameters = {"bool"_yulstring, "bool"_yulstring};
m_functions["or"_yulstring].returns = {"bool"_yulstring};
m_functions["xor"_yulstring].parameters = {"bool"_yulstring, "bool"_yulstring};
m_functions["xor"_yulstring].returns = {"bool"_yulstring};
m_functions["popbool"_yulstring] = m_functions["pop"_yulstring];
m_functions["popbool"_yulstring].name = "popbool"_yulstring;
m_functions["popbool"_yulstring].parameters = {"bool"_yulstring};
m_functions.insert(createFunction("bool_to_u256", 1, 1, {}, {}, [](
FunctionCall const& _call,
AbstractAssembly& _assembly,
BuiltinContext&,
std::function<void(Expression const&)> _visitExpression
) {
visitArguments(_assembly, _call, _visitExpression);
}));
m_functions["bool_to_u256"_yulstring].parameters = {"bool"_yulstring};
m_functions["bool_to_u256"_yulstring].returns = {"u256"_yulstring};
m_functions.insert(createFunction("u256_to_bool", 1, 1, {}, {}, [](
FunctionCall const& _call,
AbstractAssembly& _assembly,
BuiltinContext&,
std::function<void(Expression const&)> _visitExpression
) {
// A value larger than 1 causes an invalid instruction.
visitArguments(_assembly, _call, _visitExpression);
_assembly.appendConstant(2);
_assembly.appendInstruction(evmasm::Instruction::DUP2);
_assembly.appendInstruction(evmasm::Instruction::LT);
AbstractAssembly::LabelID inRange = _assembly.newLabelId();
_assembly.appendJumpToIf(inRange);
_assembly.appendInstruction(evmasm::Instruction::INVALID);
_assembly.appendLabel(inRange);
}));
m_functions["u256_to_bool"_yulstring].parameters = {"u256"_yulstring};
m_functions["u256_to_bool"_yulstring].returns = {"bool"_yulstring};
}
BuiltinFunctionForEVM const* EVMDialectTyped::discardFunction(YulString _type) const
{
if (_type == "bool"_yulstring)
return builtin("popbool"_yulstring);
else
{
yulAssert(_type == defaultType, "");
return builtin("pop"_yulstring);
}
}
BuiltinFunctionForEVM const* EVMDialectTyped::equalityFunction(YulString _type) const
{
if (_type == "bool"_yulstring)
return nullptr;
else
{
yulAssert(_type == defaultType, "");
return builtin("eq"_yulstring);
}
}
EVMDialectTyped const& EVMDialectTyped::instance(langutil::EVMVersion _version)
{
static map<langutil::EVMVersion, unique_ptr<EVMDialectTyped const>> dialects;
static YulStringRepository::ResetCallback callback{[&] { dialects.clear(); }};
if (!dialects[_version])
dialects[_version] = make_unique<EVMDialectTyped>(_version, true);
return *dialects[_version];
}