/*
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 Christian <c@ethdev.com>
* @date 2014
* Utilities for the solidity compiler.
*/
#include <libsolidity/codegen/CompilerContext.h>
#include <libsolidity/ast/AST.h>
#include <libsolidity/codegen/AsmCodeGen.h>
#include <libsolidity/codegen/Compiler.h>
#include <libsolidity/codegen/CompilerUtils.h>
#include <libsolidity/interface/Version.h>
#include <libyul/AsmParser.h>
#include <libyul/AsmAnalysis.h>
#include <libyul/AsmAnalysisInfo.h>
#include <libyul/backends/evm/EVMDialect.h>
#include <libyul/YulString.h>
#include <liblangutil/ErrorReporter.h>
#include <liblangutil/Scanner.h>
#include <liblangutil/SourceReferenceFormatter.h>
#include <boost/algorithm/string/replace.hpp>
#include <utility>
#include <numeric>
// Change to "define" to output all intermediate code
#undef SOL_OUTPUT_ASM
#ifdef SOL_OUTPUT_ASM
#include <libyul/AsmPrinter.h>
#endif
using namespace std;
using namespace langutil;
namespace dev
{
namespace solidity
{
void CompilerContext::addStateVariable(
VariableDeclaration const& _declaration,
u256 const& _storageOffset,
unsigned _byteOffset
)
{
m_stateVariables[&_declaration] = make_pair(_storageOffset, _byteOffset);
}
void CompilerContext::startFunction(Declaration const& _function)
{
m_functionCompilationQueue.startFunction(_function);
*this << functionEntryLabel(_function);
}
void CompilerContext::callLowLevelFunction(
string const& _name,
unsigned _inArgs,
unsigned _outArgs,
function<void(CompilerContext&)> const& _generator
)
{
eth::AssemblyItem retTag = pushNewTag();
CompilerUtils(*this).moveIntoStack(_inArgs);
*this << lowLevelFunctionTag(_name, _inArgs, _outArgs, _generator);
appendJump(eth::AssemblyItem::JumpType::IntoFunction);
adjustStackOffset(int(_outArgs) - 1 - _inArgs);
*this << retTag.tag();
}
eth::AssemblyItem CompilerContext::lowLevelFunctionTag(
string const& _name,
unsigned _inArgs,
unsigned _outArgs,
function<void(CompilerContext&)> const& _generator
)
{
auto it = m_lowLevelFunctions.find(_name);
if (it == m_lowLevelFunctions.end())
{
eth::AssemblyItem tag = newTag().pushTag();
m_lowLevelFunctions.insert(make_pair(_name, tag));
m_lowLevelFunctionGenerationQueue.push(make_tuple(_name, _inArgs, _outArgs, _generator));
return tag;
}
else
return it->second;
}
void CompilerContext::appendMissingLowLevelFunctions()
{
while (!m_lowLevelFunctionGenerationQueue.empty())
{
string name;
unsigned inArgs;
unsigned outArgs;
function<void(CompilerContext&)> generator;
tie(name, inArgs, outArgs, generator) = m_lowLevelFunctionGenerationQueue.front();
m_lowLevelFunctionGenerationQueue.pop();
setStackOffset(inArgs + 1);
*this << m_lowLevelFunctions.at(name).tag();
generator(*this);
CompilerUtils(*this).moveToStackTop(outArgs);
appendJump(eth::AssemblyItem::JumpType::OutOfFunction);
solAssert(stackHeight() == outArgs, "Invalid stack height in low-level function " + name + ".");
}
}
void CompilerContext::addVariable(VariableDeclaration const& _declaration,
unsigned _offsetToCurrent)
{
solAssert(m_asm->deposit() >= 0 && unsigned(m_asm->deposit()) >= _offsetToCurrent, "");
unsigned sizeOnStack = _declaration.annotation().type->sizeOnStack();
// Variables should not have stack size other than [1, 2],
// but that might change when new types are introduced.
solAssert(sizeOnStack == 1 || sizeOnStack == 2, "");
m_localVariables[&_declaration].push_back(unsigned(m_asm->deposit()) - _offsetToCurrent);
}
void CompilerContext::removeVariable(Declaration const& _declaration)
{
solAssert(m_localVariables.count(&_declaration) && !m_localVariables[&_declaration].empty(), "");
m_localVariables[&_declaration].pop_back();
if (m_localVariables[&_declaration].empty())
m_localVariables.erase(&_declaration);
}
void CompilerContext::removeVariablesAboveStackHeight(unsigned _stackHeight)
{
vector<Declaration const*> toRemove;
for (auto _var: m_localVariables)
{
solAssert(!_var.second.empty(), "");
solAssert(_var.second.back() <= stackHeight(), "");
if (_var.second.back() >= _stackHeight)
toRemove.push_back(_var.first);
}
for (auto _var: toRemove)
removeVariable(*_var);
}
unsigned CompilerContext::numberOfLocalVariables() const
{
return m_localVariables.size();
}
eth::Assembly const& CompilerContext::compiledContract(const ContractDefinition& _contract) const
{
auto ret = m_compiledContracts.find(&_contract);
solAssert(ret != m_compiledContracts.end(), "Compiled contract not found.");
return *ret->second;
}
bool CompilerContext::isLocalVariable(Declaration const* _declaration) const
{
return !!m_localVariables.count(_declaration);
}
eth::AssemblyItem CompilerContext::functionEntryLabel(Declaration const& _declaration)
{
return m_functionCompilationQueue.entryLabel(_declaration, *this);
}
eth::AssemblyItem CompilerContext::functionEntryLabelIfExists(Declaration const& _declaration) const
{
return m_functionCompilationQueue.entryLabelIfExists(_declaration);
}
FunctionDefinition const& CompilerContext::resolveVirtualFunction(FunctionDefinition const& _function)
{
// Libraries do not allow inheritance and their functions can be inlined, so we should not
// search the inheritance hierarchy (which will be the wrong one in case the function
// is inlined).
if (auto scope = dynamic_cast<ContractDefinition const*>(_function.scope()))
if (scope->isLibrary())
return _function;
solAssert(!m_inheritanceHierarchy.empty(), "No inheritance hierarchy set.");
return resolveVirtualFunction(_function, m_inheritanceHierarchy.begin());
}
FunctionDefinition const& CompilerContext::superFunction(FunctionDefinition const& _function, ContractDefinition const& _base)
{
solAssert(!m_inheritanceHierarchy.empty(), "No inheritance hierarchy set.");
return resolveVirtualFunction(_function, superContract(_base));
}
FunctionDefinition const* CompilerContext::nextConstructor(ContractDefinition const& _contract) const
{
vector<ContractDefinition const*>::const_iterator it = superContract(_contract);
for (; it != m_inheritanceHierarchy.end(); ++it)
if ((*it)->constructor())
return (*it)->constructor();
return nullptr;
}
Declaration const* CompilerContext::nextFunctionToCompile() const
{
return m_functionCompilationQueue.nextFunctionToCompile();
}
ModifierDefinition const& CompilerContext::resolveVirtualFunctionModifier(
ModifierDefinition const& _modifier
) const
{
// Libraries do not allow inheritance and their functions can be inlined, so we should not
// search the inheritance hierarchy (which will be the wrong one in case the function
// is inlined).
if (auto scope = dynamic_cast<ContractDefinition const*>(_modifier.scope()))
if (scope->isLibrary())
return _modifier;
solAssert(!m_inheritanceHierarchy.empty(), "No inheritance hierarchy set.");
for (ContractDefinition const* contract: m_inheritanceHierarchy)
for (ModifierDefinition const* modifier: contract->functionModifiers())
if (modifier->name() == _modifier.name())
return *modifier;
solAssert(false, "Function modifier " + _modifier.name() + " not found in inheritance hierarchy.");
}
unsigned CompilerContext::baseStackOffsetOfVariable(Declaration const& _declaration) const
{
auto res = m_localVariables.find(&_declaration);
solAssert(res != m_localVariables.end(), "Variable not found on stack.");
solAssert(!res->second.empty(), "");
return res->second.back();
}
unsigned CompilerContext::baseToCurrentStackOffset(unsigned _baseOffset) const
{
return m_asm->deposit() - _baseOffset - 1;
}
unsigned CompilerContext::currentToBaseStackOffset(unsigned _offset) const
{
return m_asm->deposit() - _offset - 1;
}
pair<u256, unsigned> CompilerContext::storageLocationOfVariable(const Declaration& _declaration) const
{
auto it = m_stateVariables.find(&_declaration);
solAssert(it != m_stateVariables.end(), "Variable not found in storage.");
return it->second;
}
CompilerContext& CompilerContext::appendJump(eth::AssemblyItem::JumpType _jumpType)
{
eth::AssemblyItem item(Instruction::JUMP);
item.setJumpType(_jumpType);
return *this << item;
}
CompilerContext& CompilerContext::appendInvalid()
{
return *this << Instruction::INVALID;
}
CompilerContext& CompilerContext::appendConditionalInvalid()
{
*this << Instruction::ISZERO;
eth::AssemblyItem afterTag = appendConditionalJump();
*this << Instruction::INVALID;
*this << afterTag;
return *this;
}
CompilerContext& CompilerContext::appendRevert()
{
return *this << u256(0) << u256(0) << Instruction::REVERT;
}
CompilerContext& CompilerContext::appendConditionalRevert(bool _forwardReturnData)
{
if (_forwardReturnData && m_evmVersion.supportsReturndata())
appendInlineAssembly(R"({
if condition {
returndatacopy(0, 0, returndatasize())
revert(0, returndatasize())
}
})", {"condition"});
else
appendInlineAssembly(R"({
if condition { revert(0, 0) }
})", {"condition"});
*this << Instruction::POP;
return *this;
}
void CompilerContext::resetVisitedNodes(ASTNode const* _node)
{
stack<ASTNode const*> newStack;
newStack.push(_node);
std::swap(m_visitedNodes, newStack);
updateSourceLocation();
}
void CompilerContext::appendInlineAssembly(
string const& _assembly,
vector<string> const& _localVariables,
set<string> const&,
bool _system
)
{
int startStackHeight = stackHeight();
yul::ExternalIdentifierAccess identifierAccess;
identifierAccess.resolve = [&](
yul::Identifier const& _identifier,
yul::IdentifierContext,
bool
)
{
auto it = std::find(_localVariables.begin(), _localVariables.end(), _identifier.name.str());
return it == _localVariables.end() ? size_t(-1) : 1;
};
identifierAccess.generateCode = [&](
yul::Identifier const& _identifier,
yul::IdentifierContext _context,
yul::AbstractAssembly& _assembly
)
{
auto it = std::find(_localVariables.begin(), _localVariables.end(), _identifier.name.str());
solAssert(it != _localVariables.end(), "");
int stackDepth = _localVariables.end() - it;
int stackDiff = _assembly.stackHeight() - startStackHeight + stackDepth;
if (_context == yul::IdentifierContext::LValue)
stackDiff -= 1;
if (stackDiff < 1 || stackDiff > 16)
BOOST_THROW_EXCEPTION(
CompilerError() <<
errinfo_sourceLocation(_identifier.location) <<
errinfo_comment("Stack too deep (" + to_string(stackDiff) + "), try removing local variables.")
);
if (_context == yul::IdentifierContext::RValue)
_assembly.appendInstruction(dupInstruction(stackDiff));
else
{
_assembly.appendInstruction(swapInstruction(stackDiff));
_assembly.appendInstruction(Instruction::POP);
}
};
ErrorList errors;
ErrorReporter errorReporter(errors);
auto scanner = make_shared<langutil::Scanner>(langutil::CharStream(_assembly, "--CODEGEN--"));
auto parserResult = yul::Parser(errorReporter, yul::EVMDialect::strictAssemblyForEVM()).parse(scanner, false);
#ifdef SOL_OUTPUT_ASM
cout << yul::AsmPrinter()(*parserResult) << endl;
#endif
yul::AsmAnalysisInfo analysisInfo;
bool analyzerResult = false;
if (parserResult)
analyzerResult = yul::AsmAnalyzer(
analysisInfo,
errorReporter,
m_evmVersion,
boost::none,
yul::EVMDialect::strictAssemblyForEVM(),
identifierAccess.resolve
).analyze(*parserResult);
if (!parserResult || !errorReporter.errors().empty() || !analyzerResult)
{
string message =
"Error parsing/analyzing inline assembly block:\n"
"------------------ Input: -----------------\n" +
_assembly + "\n"
"------------------ Errors: ----------------\n";
for (auto const& error: errorReporter.errors())
message += SourceReferenceFormatter::formatExceptionInformation(
*error,
(error->type() == Error::Type::Warning) ? "Warning" : "Error"
);
message += "-------------------------------------------\n";
solAssert(false, message);
}
solAssert(errorReporter.errors().empty(), "Failed to analyze inline assembly block.");
CodeGenerator::assemble(*parserResult, analysisInfo, *m_asm, identifierAccess, _system);
// Reset the source location to the one of the node (instead of the CODEGEN source location)
updateSourceLocation();
}
FunctionDefinition const& CompilerContext::resolveVirtualFunction(
FunctionDefinition const& _function,
vector<ContractDefinition const*>::const_iterator _searchStart
)
{
string name = _function.name();
FunctionType functionType(_function);
auto it = _searchStart;
for (; it != m_inheritanceHierarchy.end(); ++it)
for (FunctionDefinition const* function: (*it)->definedFunctions())
if (
function->name() == name &&
!function->isConstructor() &&
FunctionType(*function).asCallableFunction(false)->hasEqualParameterTypes(functionType)
)
return *function;
solAssert(false, "Super function " + name + " not found.");
return _function; // not reached
}
vector<ContractDefinition const*>::const_iterator CompilerContext::superContract(ContractDefinition const& _contract) const
{
solAssert(!m_inheritanceHierarchy.empty(), "No inheritance hierarchy set.");
auto it = find(m_inheritanceHierarchy.begin(), m_inheritanceHierarchy.end(), &_contract);
solAssert(it != m_inheritanceHierarchy.end(), "Base not found in inheritance hierarchy.");
return ++it;
}
void CompilerContext::updateSourceLocation()
{
m_asm->setSourceLocation(m_visitedNodes.empty() ? SourceLocation() : m_visitedNodes.top()->location());
}
eth::AssemblyItem CompilerContext::FunctionCompilationQueue::entryLabel(
Declaration const& _declaration,
CompilerContext& _context
)
{
auto res = m_entryLabels.find(&_declaration);
if (res == m_entryLabels.end())
{
eth::AssemblyItem tag(_context.newTag());
m_entryLabels.insert(make_pair(&_declaration, tag));
m_functionsToCompile.push(&_declaration);
return tag.tag();
}
else
return res->second.tag();
}
eth::AssemblyItem CompilerContext::FunctionCompilationQueue::entryLabelIfExists(Declaration const& _declaration) const
{
auto res = m_entryLabels.find(&_declaration);
return res == m_entryLabels.end() ? eth::AssemblyItem(eth::UndefinedItem) : res->second.tag();
}
Declaration const* CompilerContext::FunctionCompilationQueue::nextFunctionToCompile() const
{
while (!m_functionsToCompile.empty())
{
if (m_alreadyCompiledFunctions.count(m_functionsToCompile.front()))
m_functionsToCompile.pop();
else
return m_functionsToCompile.front();
}
return nullptr;
}
void CompilerContext::FunctionCompilationQueue::startFunction(Declaration const& _function)
{
if (!m_functionsToCompile.empty() && m_functionsToCompile.front() == &_function)
m_functionsToCompile.pop();
m_alreadyCompiledFunctions.insert(&_function);
}
}
}