solidity/libsolidity/codegen/ir/IRGenerator.cpp
2019-05-02 17:03:22 +02:00

264 lines
8.5 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/>.
*/
/**
* @author Alex Beregszaszi
* @date 2017
* Component that translates Solidity code into Yul.
*/
#include <libsolidity/codegen/ir/IRGenerator.h>
#include <libsolidity/codegen/ir/IRGeneratorForStatements.h>
#include <libsolidity/ast/AST.h>
#include <libsolidity/ast/ASTVisitor.h>
#include <libsolidity/codegen/ABIFunctions.h>
#include <libsolidity/codegen/CompilerUtils.h>
#include <libyul/AssemblyStack.h>
#include <libdevcore/CommonData.h>
#include <libdevcore/Whiskers.h>
#include <libdevcore/StringUtils.h>
#include <liblangutil/SourceReferenceFormatter.h>
#include <boost/algorithm/string/predicate.hpp>
using namespace std;
using namespace dev;
using namespace dev::solidity;
pair<string, string> IRGenerator::run(ContractDefinition const& _contract)
{
// TODO Would be nice to pretty-print this while retaining comments.
string ir = generate(_contract);
yul::AssemblyStack asmStack(m_evmVersion, yul::AssemblyStack::Language::StrictAssembly, m_optimiserSettings);
if (!asmStack.parseAndAnalyze("", ir))
{
string errorMessage;
for (auto const& error: asmStack.errors())
errorMessage += langutil::SourceReferenceFormatter::formatErrorInformation(*error);
solAssert(false, "Invalid IR generated:\n" + errorMessage + "\n" + ir);
}
asmStack.optimize();
string warning =
"/*******************************************************\n"
" * WARNING *\n"
" * Solidity to Yul compilation is still EXPERIMENTAL *\n"
" * It can result in LOSS OF FUNDS or worse *\n"
" * !USE AT YOUR OWN RISK! *\n"
" *******************************************************/\n\n";
return {warning + ir, warning + asmStack.print()};
}
string IRGenerator::generate(ContractDefinition const& _contract)
{
Whiskers t(R"(
object "<CreationObject>" {
code {
<memoryInit>
<constructor>
<deploy>
<functions>
}
object "<RuntimeObject>" {
code {
<memoryInit>
<dispatch>
<runtimeFunctions>
}
}
}
)");
resetContext(_contract);
t("CreationObject", creationObjectName(_contract));
t("memoryInit", memoryInit());
t("constructor", _contract.constructor() ? constructorCode(*_contract.constructor()) : "");
t("deploy", deployCode(_contract));
t("functions", m_context.functionCollector()->requestedFunctions());
resetContext(_contract);
m_context.setInheritanceHierarchy(_contract.annotation().linearizedBaseContracts);
t("RuntimeObject", runtimeObjectName(_contract));
t("dispatch", dispatchRoutine(_contract));
t("runtimeFunctions", m_context.functionCollector()->requestedFunctions());
return t.render();
}
string IRGenerator::generate(Block const& _block)
{
IRGeneratorForStatements generator(m_context, m_utils);
_block.accept(generator);
return generator.code();
}
string IRGenerator::generateFunction(FunctionDefinition const& _function)
{
string functionName = m_context.functionName(_function);
return m_context.functionCollector()->createFunction(functionName, [&]() {
Whiskers t(R"(
function <functionName>(<params>) <returns> {
for { let return_flag := 1 } return_flag {} {
<body>
break
}
}
)");
t("functionName", functionName);
string params;
for (auto const& varDecl: _function.parameters())
params += (params.empty() ? "" : ", ") + m_context.addLocalVariable(*varDecl);
t("params", params);
string retParams;
for (auto const& varDecl: _function.returnParameters())
retParams += (retParams.empty() ? "" : ", ") + m_context.addLocalVariable(*varDecl);
t("returns", retParams.empty() ? "" : " -> " + retParams);
t("body", generate(_function.body()));
return t.render();
});
}
string IRGenerator::constructorCode(FunctionDefinition const& _constructor)
{
string out;
if (!_constructor.isPayable())
out = callValueCheck();
solUnimplemented("Constructors are not yet implemented.");
return out;
}
string IRGenerator::deployCode(ContractDefinition const& _contract)
{
Whiskers t(R"X(
codecopy(0, dataoffset("<object>"), datasize("<object>"))
return(0, datasize("<object>"))
)X");
t("object", runtimeObjectName(_contract));
return t.render();
}
string IRGenerator::callValueCheck()
{
return "if callvalue() { revert(0, 0) }";
}
string IRGenerator::creationObjectName(ContractDefinition const& _contract)
{
return _contract.name() + "_" + to_string(_contract.id());
}
string IRGenerator::runtimeObjectName(ContractDefinition const& _contract)
{
return _contract.name() + "_" + to_string(_contract.id()) + "_deployed";
}
string IRGenerator::dispatchRoutine(ContractDefinition const& _contract)
{
Whiskers t(R"X(
if iszero(lt(calldatasize(), 4))
{
let selector := <shr224>(calldataload(0))
switch selector
<#cases>
case <functionSelector>
{
// <functionName>
<callValueCheck>
<assignToParams> <abiDecode>(4, calldatasize())
<assignToRetParams> <function>(<params>)
let memPos := <allocate>(0)
let memEnd := <abiEncode>(memPos <comma> <retParams>)
return(memPos, sub(memEnd, memPos))
}
</cases>
default {}
}
<fallback>
)X");
t("shr224", m_utils.shiftRightFunction(224));
vector<map<string, string>> functions;
for (auto const& function: _contract.interfaceFunctions())
{
functions.push_back({});
map<string, string>& templ = functions.back();
templ["functionSelector"] = "0x" + function.first.hex();
FunctionTypePointer const& type = function.second;
templ["functionName"] = type->externalSignature();
templ["callValueCheck"] = type->isPayable() ? "" : callValueCheck();
unsigned paramVars = make_shared<TupleType>(type->parameterTypes())->sizeOnStack();
unsigned retVars = make_shared<TupleType>(type->returnParameterTypes())->sizeOnStack();
templ["assignToParams"] = paramVars == 0 ? "" : "let " + m_utils.suffixedVariableNameList("param_", 0, paramVars) + " := ";
templ["assignToRetParams"] = retVars == 0 ? "" : "let " + m_utils.suffixedVariableNameList("ret_", 0, retVars) + " := ";
ABIFunctions abiFunctions(m_evmVersion, m_context.functionCollector());
templ["abiDecode"] = abiFunctions.tupleDecoder(type->parameterTypes());
templ["params"] = m_utils.suffixedVariableNameList("param_", 0, paramVars);
templ["retParams"] = m_utils.suffixedVariableNameList("ret_", retVars, 0);
templ["function"] = generateFunction(dynamic_cast<FunctionDefinition const&>(type->declaration()));
templ["allocate"] = m_utils.allocationFunction();
templ["abiEncode"] = abiFunctions.tupleEncoder(type->returnParameterTypes(), type->returnParameterTypes(), false);
templ["comma"] = retVars == 0 ? "" : ", ";
}
t("cases", functions);
if (FunctionDefinition const* fallback = _contract.fallbackFunction())
{
string fallbackCode;
if (!fallback->isPayable())
fallbackCode += callValueCheck();
fallbackCode += generateFunction(*fallback) + "() stop()";
t("fallback", fallbackCode);
}
else
t("fallback", "revert(0, 0)");
return t.render();
}
string IRGenerator::memoryInit()
{
// This function should be called at the beginning of the EVM call frame
// and thus can assume all memory to be zero, including the contents of
// the "zero memory area" (the position CompilerUtils::zeroPointer points to).
return
Whiskers{"mstore(<memPtr>, <generalPurposeStart>)"}
("memPtr", to_string(CompilerUtils::freeMemoryPointer))
("generalPurposeStart", to_string(CompilerUtils::generalPurposeMemoryStart))
.render();
}
void IRGenerator::resetContext(ContractDefinition const& _contract)
{
solAssert(
m_context.functionCollector()->requestedFunctions().empty(),
"Reset context while it still had functions."
);
m_context = IRGenerationContext(m_evmVersion, m_optimiserSettings);
m_utils = YulUtilFunctions(m_evmVersion, m_context.functionCollector());
m_context.setInheritanceHierarchy(_contract.annotation().linearizedBaseContracts);
for (auto const& var: ContractType(_contract).stateVariables())
m_context.addStateVariable(*get<0>(var), get<1>(var), get<2>(var));
}