solidity/libsolidity/codegen/ir/IRGenerator.cpp
2020-05-04 15:00:50 +02:00

562 lines
19 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 <libyul/Utilities.h>
#include <libsolutil/CommonData.h>
#include <libsolutil/Whiskers.h>
#include <libsolutil/StringUtils.h>
#include <liblangutil/SourceReferenceFormatter.h>
#include <boost/algorithm/string/predicate.hpp>
#include <boost/range/adaptor/reversed.hpp>
#include <sstream>
using namespace std;
using namespace solidity;
using namespace solidity::util;
using namespace solidity::frontend;
pair<string, string> IRGenerator::run(
ContractDefinition const& _contract,
map<ContractDefinition const*, string const> const& _otherYulSources
)
{
string const ir = yul::reindent(generate(_contract, _otherYulSources));
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, ir + "\n\nInvalid IR generated:\n" + errorMessage + "\n");
}
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,
map<ContractDefinition const*, string const> const& _otherYulSources
)
{
auto subObjectSources = [&_otherYulSources](std::set<ContractDefinition const*, ASTNode::CompareByID> const& subObjects) -> string
{
std::string subObjectsSources;
for (ContractDefinition const* subObject: subObjects)
subObjectsSources += _otherYulSources.at(subObject);
return subObjectsSources;
};
Whiskers t(R"(
object "<CreationObject>" {
code {
<memoryInit>
<callValueCheck>
<?notLibrary>
<?constructorHasParams> let <constructorParams> := <copyConstructorArguments>() </constructorHasParams>
<implicitConstructor>(<constructorParams>)
</notLibrary>
<deploy>
<functions>
}
object "<RuntimeObject>" {
code {
<memoryInit>
<dispatch>
<runtimeFunctions>
}
<runtimeSubObjects>
}
<subObjects>
}
)");
resetContext(_contract);
for (VariableDeclaration const* var: ContractType(_contract).immutableVariables())
m_context.registerImmutableVariable(*var);
t("CreationObject", m_context.creationObjectName(_contract));
t("memoryInit", memoryInit());
t("notLibrary", !_contract.isLibrary());
FunctionDefinition const* constructor = _contract.constructor();
t("callValueCheck", !constructor || !constructor->isPayable() ? callValueCheck() : "");
vector<string> constructorParams;
if (constructor && !constructor->parameters().empty())
{
for (size_t i = 0; i < constructor->parameters().size(); ++i)
constructorParams.emplace_back(m_context.newYulVariable());
t(
"copyConstructorArguments",
m_utils.copyConstructorArgumentsToMemoryFunction(_contract, m_context.creationObjectName(_contract))
);
}
t("constructorParams", joinHumanReadable(constructorParams));
t("constructorHasParams", !constructorParams.empty());
t("implicitConstructor", implicitConstructorName(_contract));
t("deploy", deployCode(_contract));
generateImplicitConstructors(_contract);
generateQueuedFunctions();
t("functions", m_context.functionCollector().requestedFunctions());
t("subObjects", subObjectSources(m_context.subObjectsCreated()));
resetContext(_contract);
// Do not register immutables to avoid assignment.
t("RuntimeObject", m_context.runtimeObjectName(_contract));
t("dispatch", dispatchRoutine(_contract));
generateQueuedFunctions();
t("runtimeFunctions", m_context.functionCollector().requestedFunctions());
t("runtimeSubObjects", subObjectSources(m_context.subObjectsCreated()));
return t.render();
}
string IRGenerator::generate(Block const& _block)
{
IRGeneratorForStatements generator(m_context, m_utils);
_block.accept(generator);
return generator.code();
}
void IRGenerator::generateQueuedFunctions()
{
while (!m_context.functionGenerationQueueEmpty())
// NOTE: generateFunction() may modify function generation queue
generateFunction(*m_context.dequeueFunctionForCodeGeneration());
}
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> {
<initReturnVariables>
<body>
}
)");
t("functionName", functionName);
string params;
for (auto const& varDecl: _function.parameters())
params += (params.empty() ? "" : ", ") + m_context.addLocalVariable(*varDecl).commaSeparatedList();
t("params", params);
string retParams;
string retInit;
for (auto const& varDecl: _function.returnParameters())
{
retParams += (retParams.empty() ? "" : ", ") + m_context.addLocalVariable(*varDecl).commaSeparatedList();
retInit += generateInitialAssignment(*varDecl);
}
t("returns", retParams.empty() ? "" : " -> " + retParams);
t("initReturnVariables", retInit);
t("body", generate(_function.body()));
return t.render();
});
}
string IRGenerator::generateGetter(VariableDeclaration const& _varDecl)
{
string functionName = m_context.functionName(_varDecl);
Type const* type = _varDecl.annotation().type;
solAssert(!_varDecl.isConstant(), "");
solAssert(_varDecl.isStateVariable(), "");
if (auto const* mappingType = dynamic_cast<MappingType const*>(type))
return m_context.functionCollector().createFunction(functionName, [&]() {
pair<u256, unsigned> slot_offset = m_context.storageLocationOfVariable(_varDecl);
solAssert(slot_offset.second == 0, "");
FunctionType funType(_varDecl);
solUnimplementedAssert(funType.returnParameterTypes().size() == 1, "");
TypePointer returnType = funType.returnParameterTypes().front();
unsigned num_keys = 0;
stringstream indexAccesses;
string slot = m_context.newYulVariable();
do
{
solUnimplementedAssert(
mappingType->keyType()->sizeOnStack() == 1,
"Multi-slot mapping key unimplemented - might not be a problem"
);
indexAccesses <<
slot <<
" := " <<
m_utils.mappingIndexAccessFunction(*mappingType, *mappingType->keyType()) <<
"(" <<
slot;
if (mappingType->keyType()->sizeOnStack() > 0)
indexAccesses <<
", " <<
suffixedVariableNameList("key", num_keys, num_keys + mappingType->keyType()->sizeOnStack());
indexAccesses << ")\n";
num_keys += mappingType->keyType()->sizeOnStack();
}
while ((mappingType = dynamic_cast<MappingType const*>(mappingType->valueType())));
return Whiskers(R"(
function <functionName>(<keys>) -> rval {
let <slot> := <base>
<indexAccesses>
rval := <readStorage>(<slot>)
}
)")
("functionName", functionName)
("keys", suffixedVariableNameList("key", 0, num_keys))
("readStorage", m_utils.readFromStorage(*returnType, 0, false))
("indexAccesses", indexAccesses.str())
("slot", slot)
("base", slot_offset.first.str())
.render();
});
else
{
solUnimplementedAssert(type->isValueType(), "");
return m_context.functionCollector().createFunction(functionName, [&]() {
if (_varDecl.immutable())
{
solUnimplementedAssert(type->sizeOnStack() == 1, "");
return Whiskers(R"(
function <functionName>() -> rval {
rval := loadimmutable("<id>")
}
)")
("functionName", functionName)
("id", to_string(_varDecl.id()))
.render();
}
else
{
pair<u256, unsigned> slot_offset = m_context.storageLocationOfVariable(_varDecl);
return Whiskers(R"(
function <functionName>() -> rval {
rval := <readStorage>(<slot>)
}
)")
("functionName", functionName)
("readStorage", m_utils.readFromStorage(*type, slot_offset.second, false))
("slot", slot_offset.first.str())
.render();
}
});
}
}
string IRGenerator::generateInitialAssignment(VariableDeclaration const& _varDecl)
{
IRGeneratorForStatements generator(m_context, m_utils);
generator.initializeLocalVar(_varDecl);
return generator.code();
}
pair<string, map<ContractDefinition const*, string>> IRGenerator::evaluateConstructorArguments(
ContractDefinition const& _contract
)
{
map<ContractDefinition const*, string> constructorParams;
vector<pair<ContractDefinition const*, std::vector<ASTPointer<Expression>>const *>> baseConstructorArguments;
for (ASTPointer<InheritanceSpecifier> const& base: _contract.baseContracts())
if (FunctionDefinition const* baseConstructor = dynamic_cast<ContractDefinition const*>(
base->name().annotation().referencedDeclaration
)->constructor(); baseConstructor && base->arguments())
baseConstructorArguments.emplace_back(
dynamic_cast<ContractDefinition const*>(baseConstructor->scope()),
base->arguments()
);
if (FunctionDefinition const* constructor = _contract.constructor())
for (auto const& modifier: constructor->modifiers())
if (FunctionDefinition const* baseConstructor = dynamic_cast<ContractDefinition const*>(
modifier->name()->annotation().referencedDeclaration
)->constructor(); baseConstructor && modifier->arguments())
baseConstructorArguments.emplace_back(
dynamic_cast<ContractDefinition const*>(baseConstructor->scope()),
modifier->arguments()
);
IRGeneratorForStatements generator{m_context, m_utils};
for (auto&& [baseContract, arguments]: baseConstructorArguments)
{
solAssert(baseContract && arguments, "");
if (baseContract->constructor() && !arguments->empty())
{
vector<string> params;
for (size_t i = 0; i < arguments->size(); ++i)
params.emplace_back(generator.evaluateExpression(
*(arguments->at(i)),
*(baseContract->constructor()->parameters()[i]->type())
).commaSeparatedList());
constructorParams[baseContract] = joinHumanReadable(params);
}
}
return {generator.code(), constructorParams};
}
string IRGenerator::initStateVariables(ContractDefinition const& _contract)
{
IRGeneratorForStatements generator{m_context, m_utils};
for (VariableDeclaration const* variable: _contract.stateVariables())
if (!variable->isConstant())
generator.initializeStateVar(*variable);
return generator.code();
}
void IRGenerator::generateImplicitConstructors(ContractDefinition const& _contract)
{
auto listAllParams = [&](
map<ContractDefinition const*, string> const& baseParams) -> string
{
vector<string> params;
for (ContractDefinition const* contract: _contract.annotation().linearizedBaseContracts)
if (baseParams.count(contract))
params.emplace_back(baseParams.at(contract));
return joinHumanReadable(params);
};
map<ContractDefinition const*, string> baseConstructorParams;
for (size_t i = 0; i < _contract.annotation().linearizedBaseContracts.size(); ++i)
{
ContractDefinition const* contract = _contract.annotation().linearizedBaseContracts[i];
baseConstructorParams.erase(contract);
m_context.functionCollector().createFunction(implicitConstructorName(*contract), [&]() {
Whiskers t(R"(
function <functionName>(<params><comma><baseParams>) {
<evalBaseArguments>
<?hasNextConstructor> <nextConstructor>(<nextParams>) </hasNextConstructor>
<initStateVariables>
<userDefinedConstructorBody>
}
)");
string params;
if (contract->constructor())
for (ASTPointer<VariableDeclaration> const& varDecl: contract->constructor()->parameters())
params += (params.empty() ? "" : ", ") + m_context.addLocalVariable(*varDecl).commaSeparatedList();
t("params", params);
string baseParamsString = listAllParams(baseConstructorParams);
t("baseParams", baseParamsString);
t("comma", !params.empty() && !baseParamsString.empty() ? ", " : "");
t("functionName", implicitConstructorName(*contract));
pair<string, map<ContractDefinition const*, string>> evaluatedArgs = evaluateConstructorArguments(*contract);
baseConstructorParams.insert(evaluatedArgs.second.begin(), evaluatedArgs.second.end());
t("evalBaseArguments", evaluatedArgs.first);
if (i < _contract.annotation().linearizedBaseContracts.size() - 1)
{
t("hasNextConstructor", true);
ContractDefinition const* nextContract = _contract.annotation().linearizedBaseContracts[i + 1];
t("nextConstructor", implicitConstructorName(*nextContract));
t("nextParams", listAllParams(baseConstructorParams));
}
else
t("hasNextConstructor", false);
t("initStateVariables", initStateVariables(*contract));
t("userDefinedConstructorBody", contract->constructor() ? generate(contract->constructor()->body()) : "");
return t.render();
});
}
}
string IRGenerator::deployCode(ContractDefinition const& _contract)
{
Whiskers t(R"X(
<#loadImmutables>
let <var> := mload(<memoryOffset>)
</loadImmutables>
codecopy(0, dataoffset("<object>"), datasize("<object>"))
<#storeImmutables>
setimmutable("<immutableName>", <var>)
</storeImmutables>
return(0, datasize("<object>"))
)X");
t("object", m_context.runtimeObjectName(_contract));
vector<map<string, string>> loadImmutables;
vector<map<string, string>> storeImmutables;
for (VariableDeclaration const* immutable: ContractType(_contract).immutableVariables())
{
solUnimplementedAssert(immutable->type()->isValueType(), "");
solUnimplementedAssert(immutable->type()->sizeOnStack() == 1, "");
string yulVar = m_context.newYulVariable();
loadImmutables.emplace_back(map<string, string>{
{"var"s, yulVar},
{"memoryOffset"s, to_string(m_context.immutableMemoryOffset(*immutable))}
});
storeImmutables.emplace_back(map<string, string>{
{"var"s, yulVar},
{"immutableName"s, to_string(immutable->id())}
});
}
t("loadImmutables", std::move(loadImmutables));
// reverse order to ease stack strain
reverse(storeImmutables.begin(), storeImmutables.end());
t("storeImmutables", std::move(storeImmutables));
return t.render();
}
string IRGenerator::callValueCheck()
{
return "if callvalue() { revert(0, 0) }";
}
string IRGenerator::implicitConstructorName(ContractDefinition const& _contract)
{
return "constructor_" + _contract.name() + "_" + to_string(_contract.id());
}
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 {}
}
if iszero(calldatasize()) { <receiveEther> }
<fallback>
)X");
t("shr224", m_utils.shiftRightFunction(224));
vector<map<string, string>> functions;
for (auto const& function: _contract.interfaceFunctions())
{
functions.emplace_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 " + suffixedVariableNameList("param_", 0, paramVars) + " := ";
templ["assignToRetParams"] = retVars == 0 ? "" : "let " + suffixedVariableNameList("ret_", 0, retVars) + " := ";
ABIFunctions abiFunctions(m_evmVersion, m_context.revertStrings(), m_context.functionCollector());
templ["abiDecode"] = abiFunctions.tupleDecoder(type->parameterTypes());
templ["params"] = suffixedVariableNameList("param_", 0, paramVars);
templ["retParams"] = suffixedVariableNameList("ret_", retVars, 0);
if (FunctionDefinition const* funDef = dynamic_cast<FunctionDefinition const*>(&type->declaration()))
templ["function"] = m_context.enqueueFunctionForCodeGeneration(*funDef);
else if (VariableDeclaration const* varDecl = dynamic_cast<VariableDeclaration const*>(&type->declaration()))
templ["function"] = generateGetter(*varDecl);
else
solAssert(false, "Unexpected declaration for function!");
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 += m_context.enqueueFunctionForCodeGeneration(*fallback) + "() stop()";
t("fallback", fallbackCode);
}
else
t("fallback", "revert(0, 0)");
if (FunctionDefinition const* etherReceiver = _contract.receiveFunction())
t("receiveEther", m_context.enqueueFunctionForCodeGeneration(*etherReceiver) + "() stop()");
else
t("receiveEther", "");
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>, <freeMemoryStart>)"}
("memPtr", to_string(CompilerUtils::freeMemoryPointer))
("freeMemoryStart", to_string(CompilerUtils::generalPurposeMemoryStart + m_context.reservedMemory()))
.render();
}
void IRGenerator::resetContext(ContractDefinition const& _contract)
{
solAssert(
m_context.functionGenerationQueueEmpty(),
"Reset function generation queue while it still had functions."
);
solAssert(
m_context.functionCollector().requestedFunctions().empty(),
"Reset context while it still had functions."
);
m_context = IRGenerationContext(m_evmVersion, m_context.revertStrings(), m_optimiserSettings);
m_context.setMostDerivedContract(_contract);
for (auto const& var: ContractType(_contract).stateVariables())
m_context.addStateVariable(*get<0>(var), get<1>(var), get<2>(var));
}