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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
#include <test/tools/ossfuzz/protoToYul.h>
#include <test/tools/ossfuzz/yulOptimizerFuzzDictionary.h>
#include <libyul/Exceptions.h>
#include <libsolutil/StringUtils.h>
#include <boost/algorithm/cxx11/all_of.hpp>
#include <boost/algorithm/string/classification.hpp>
#include <boost/algorithm/string/split.hpp>
#include <boost/range/algorithm_ext/erase.hpp>
using namespace std;
using namespace solidity::yul::test::yul_fuzzer;
using namespace solidity::yul::test;
using namespace solidity::langutil;
using namespace solidity::util;
using namespace solidity;
string ProtoConverter::dictionaryToken(HexPrefix _p)
{
std::string token;
// If dictionary constant is requested while converting
// for loop condition, then return zero so that we don't
// generate infinite for loops.
if (m_inForCond)
token = "0";
else
{
unsigned indexVar = m_inputSize * m_inputSize + counter();
token = hexDictionary[indexVar % hexDictionary.size()];
yulAssert(token.size() <= 64, "Proto Fuzzer: Dictionary token too large");
}
return _p == HexPrefix::Add ? "0x" + token : token;
}
string ProtoConverter::createHex(string const& _hexBytes)
{
string tmp{_hexBytes};
if (!tmp.empty())
{
boost::range::remove_erase_if(tmp, [=](char c) -> bool {
return !std::isxdigit(c);
});
tmp = tmp.substr(0, 64);
}
// We need this awkward if case because hex literals cannot be empty.
// Use a dictionary token.
if (tmp.empty())
tmp = dictionaryToken(HexPrefix::DontAdd);
// Hex literals must have even number of digits
if (tmp.size() % 2)
tmp.insert(0, "0");
yulAssert(tmp.size() <= 64, "Proto Fuzzer: Dictionary token too large");
return tmp;
}
string ProtoConverter::createAlphaNum(string const& _strBytes)
{
string tmp{_strBytes};
if (!tmp.empty())
{
boost::range::remove_erase_if(tmp, [=](char c) -> bool {
return !(std::isalpha(c) || std::isdigit(c));
});
tmp = tmp.substr(0, 32);
}
return tmp;
}
EVMVersion ProtoConverter::evmVersionMapping(Program_Version const& _ver)
{
switch (_ver)
{
case Program::HOMESTEAD:
return EVMVersion::homestead();
case Program::TANGERINE:
return EVMVersion::tangerineWhistle();
case Program::SPURIOUS:
return EVMVersion::spuriousDragon();
case Program::BYZANTIUM:
return EVMVersion::byzantium();
case Program::CONSTANTINOPLE:
return EVMVersion::constantinople();
case Program::PETERSBURG:
return EVMVersion::petersburg();
case Program::ISTANBUL:
return EVMVersion::istanbul();
case Program::BERLIN:
return EVMVersion::berlin();
}
}
string ProtoConverter::visit(Literal const& _x)
{
switch (_x.literal_oneof_case())
{
case Literal::kIntval:
return to_string(_x.intval());
case Literal::kHexval:
return "0x" + createHex(_x.hexval());
case Literal::kStrval:
return "\"" + createAlphaNum(_x.strval()) + "\"";
case Literal::kBoolval:
return _x.boolval() ? "true" : "false";
case Literal::LITERAL_ONEOF_NOT_SET:
return dictionaryToken();
}
}
void ProtoConverter::consolidateVarDeclsInFunctionDef()
{
m_currentFuncVars.clear();
yulAssert(!m_funcVars.empty(), "Proto fuzzer: Invalid operation");
auto const& scopes = m_funcVars.back();
for (auto const& s: scopes)
for (auto const& var: s)
m_currentFuncVars.push_back(&var);
yulAssert(!m_funcForLoopInitVars.empty(), "Proto fuzzer: Invalid operation");
auto const& forinitscopes = m_funcForLoopInitVars.back();
for (auto const& s: forinitscopes)
for (auto const& var: s)
m_currentFuncVars.push_back(&var);
}
void ProtoConverter::consolidateGlobalVarDecls()
{
m_currentGlobalVars.clear();
// Place pointers to all global variables that are in scope
// into a single vector
for (auto const& scope: m_globalVars)
for (auto const& var: scope)
m_currentGlobalVars.push_back(&var);
// Place pointers to all variables declared in for-init blocks
// that are still live into the same vector
for (auto const& init: m_globalForLoopInitVars)
for (auto const& var: init)
m_currentGlobalVars.push_back(&var);
}
bool ProtoConverter::varDeclAvailable()
{
if (m_inFunctionDef)
{
consolidateVarDeclsInFunctionDef();
return !m_currentFuncVars.empty();
}
else
{
consolidateGlobalVarDecls();
return !m_currentGlobalVars.empty();
}
}
bool ProtoConverter::functionCallNotPossible(FunctionCall_Returns _type)
{
return _type == FunctionCall::SINGLE ||
(_type == FunctionCall::MULTIASSIGN && !varDeclAvailable());
}
unsigned ProtoConverter::numVarsInScope()
{
if (m_inFunctionDef)
return static_cast<unsigned>(m_currentFuncVars.size());
else
return static_cast<unsigned>(m_currentGlobalVars.size());
}
void ProtoConverter::visit(VarRef const& _x)
{
if (m_inFunctionDef)
{
// Ensure that there is at least one variable declaration to reference in function scope.
yulAssert(!m_currentFuncVars.empty(), "Proto fuzzer: No variables to reference.");
m_output << *m_currentFuncVars[static_cast<size_t>(_x.varnum()) % m_currentFuncVars.size()];
}
else
{
// Ensure that there is at least one variable declaration to reference in nested scopes.
yulAssert(!m_currentGlobalVars.empty(), "Proto fuzzer: No global variables to reference.");
m_output << *m_currentGlobalVars[static_cast<size_t>(_x.varnum()) % m_currentGlobalVars.size()];
}
}
void ProtoConverter::visit(Expression const& _x)
{
switch (_x.expr_oneof_case())
{
case Expression::kVarref:
// If the expression requires a variable reference that we cannot provide
// (because there are no variables in scope), we silently output a literal
// expression from the optimizer dictionary.
if (!varDeclAvailable())
m_output << dictionaryToken();
else
visit(_x.varref());
break;
case Expression::kCons:
// If literal expression describes for-loop condition
// then force it to zero, so we don't generate infinite
// for loops
if (m_inForCond)
m_output << "0";
else
m_output << visit(_x.cons());
break;
case Expression::kBinop:
visit(_x.binop());
break;
case Expression::kUnop:
visit(_x.unop());
break;
case Expression::kTop:
visit(_x.top());
break;
case Expression::kNop:
visit(_x.nop());
break;
case Expression::kFuncExpr:
// FunctionCall must return a single value, otherwise
// we output a trivial expression "1".
if (_x.func_expr().ret() == FunctionCall::SINGLE)
visit(_x.func_expr());
else
m_output << dictionaryToken();
break;
case Expression::kLowcall:
visit(_x.lowcall());
break;
case Expression::kCreate:
// Create and create2 return address of created contract which
// may lead to state change via sstore of the returned address.
if (!m_filterStatefulInstructions)
visit(_x.create());
else
m_output << dictionaryToken();
break;
case Expression::kUnopdata:
// Filter datasize and dataoffset because these instructions may return
// a value that is a function of optimisation. Therefore, when run on
// an EVM client, the execution traces for unoptimised vs optimised
// programs may differ. This ends up as a false-positive bug report.
if (m_isObject && !m_filterStatefulInstructions)
visit(_x.unopdata());
else
m_output << dictionaryToken();
break;
case Expression::EXPR_ONEOF_NOT_SET:
m_output << dictionaryToken();
break;
}
}
void ProtoConverter::visit(BinaryOp const& _x)
{
BinaryOp_BOp op = _x.op();
if ((op == BinaryOp::SHL || op == BinaryOp::SHR || op == BinaryOp::SAR) &&
!m_evmVersion.hasBitwiseShifting())
{
m_output << dictionaryToken();
return;
}
switch (op)
{
case BinaryOp::ADD:
m_output << "add";
break;
case BinaryOp::SUB:
m_output << "sub";
break;
case BinaryOp::MUL:
m_output << "mul";
break;
case BinaryOp::DIV:
m_output << "div";
break;
case BinaryOp::MOD:
m_output << "mod";
break;
case BinaryOp::XOR:
m_output << "xor";
break;
case BinaryOp::AND:
m_output << "and";
break;
case BinaryOp::OR:
m_output << "or";
break;
case BinaryOp::EQ:
m_output << "eq";
break;
case BinaryOp::LT:
m_output << "lt";
break;
case BinaryOp::GT:
m_output << "gt";
break;
case BinaryOp::SHR:
yulAssert(m_evmVersion.hasBitwiseShifting(), "Proto fuzzer: Invalid evm version");
m_output << "shr";
break;
case BinaryOp::SHL:
yulAssert(m_evmVersion.hasBitwiseShifting(), "Proto fuzzer: Invalid evm version");
m_output << "shl";
break;
case BinaryOp::SAR:
yulAssert(m_evmVersion.hasBitwiseShifting(), "Proto fuzzer: Invalid evm version");
m_output << "sar";
break;
case BinaryOp::SDIV:
m_output << "sdiv";
break;
case BinaryOp::SMOD:
m_output << "smod";
break;
case BinaryOp::EXP:
m_output << "exp";
break;
case BinaryOp::SLT:
m_output << "slt";
break;
case BinaryOp::SGT:
m_output << "sgt";
break;
case BinaryOp::BYTE:
m_output << "byte";
break;
case BinaryOp::SI:
m_output << "signextend";
break;
case BinaryOp::KECCAK:
m_output << "keccak256";
break;
}
m_output << "(";
visit(_x.left());
m_output << ",";
visit(_x.right());
m_output << ")";
}
void ProtoConverter::scopeVariables(vector<string> const& _varNames)
{
// If we are inside a for-init block, there are two places
// where the visited vardecl may have been defined:
// - directly inside the for-init block
// - inside a block within the for-init block
// In the latter case, we don't scope extend. The flag
// m_forInitScopeExtEnabled (= true) indicates whether we are directly
// inside a for-init block e.g., for { let x } or (= false) inside a
// nested for-init block e.g., for { { let x } }
bool forInitScopeExtendVariable = m_inForInitScope && m_forInitScopeExtEnabled;
// There are four cases that are tackled here
// Case 1. We are inside a function definition and the variable declaration's
// scope needs to be extended.
// Case 2. We are inside a function definition but scope extension is disabled
// Case 3. We are inside global scope and scope extension is required
// Case 4. We are inside global scope but scope extension is disabled
if (m_inFunctionDef)
{
// Variables declared directly in for-init block
// are tracked separately because their scope
// extends beyond the block they are defined in
// to the rest of the for-loop statement.
// Case 1
if (forInitScopeExtendVariable)
{
yulAssert(
!m_funcForLoopInitVars.empty() && !m_funcForLoopInitVars.back().empty(),
"Proto fuzzer: Invalid operation"
);
for (auto const& varName: _varNames)
m_funcForLoopInitVars.back().back().push_back(varName);
}
// Case 2
else
{
yulAssert(
!m_funcVars.empty() && !m_funcVars.back().empty(),
"Proto fuzzer: Invalid operation"
);
for (auto const& varName: _varNames)
m_funcVars.back().back().push_back(varName);
}
}
// If m_inFunctionDef is false, we are in global scope
else
{
// Case 3
if (forInitScopeExtendVariable)
{
yulAssert(!m_globalForLoopInitVars.empty(), "Proto fuzzer: Invalid operation");
for (auto const& varName: _varNames)
m_globalForLoopInitVars.back().push_back(varName);
}
// Case 4
else
{
yulAssert(!m_globalVars.empty(), "Proto fuzzer: Invalid operation");
for (auto const& varName: _varNames)
m_globalVars.back().push_back(varName);
}
}
}
void ProtoConverter::visit(VarDecl const& _x)
{
string varName = newVarName();
m_output << "let " << varName << " := ";
visit(_x.expr());
m_output << "\n";
scopeVariables({varName});
}
void ProtoConverter::visit(MultiVarDecl const& _x)
{
m_output << "let ";
vector<string> varNames;
// We support up to 4 variables in a single
// declaration statement.
unsigned numVars = _x.num_vars() % 3 + 2;
string delimiter;
for (unsigned i = 0; i < numVars; i++)
{
string varName = newVarName();
varNames.push_back(varName);
m_output << delimiter << varName;
if (i == 0)
delimiter = ", ";
}
m_output << "\n";
scopeVariables(varNames);
}
void ProtoConverter::visit(TypedVarDecl const& _x)
{
string varName = newVarName();
m_output << "let " << varName;
switch (_x.type())
{
case TypedVarDecl::BOOL:
m_output << ": bool := ";
visit(_x.expr());
m_output << " : bool\n";
break;
case TypedVarDecl::S8:
m_output << ": s8 := ";
visit(_x.expr());
m_output << " : s8\n";
break;
case TypedVarDecl::S32:
m_output << ": s32 := ";
visit(_x.expr());
m_output << " : s32\n";
break;
case TypedVarDecl::S64:
m_output << ": s64 := ";
visit(_x.expr());
m_output << " : s64\n";
break;
case TypedVarDecl::S128:
m_output << ": s128 := ";
visit(_x.expr());
m_output << " : s128\n";
break;
case TypedVarDecl::S256:
m_output << ": s256 := ";
visit(_x.expr());
m_output << " : s256\n";
break;
case TypedVarDecl::U8:
m_output << ": u8 := ";
visit(_x.expr());
m_output << " : u8\n";
break;
case TypedVarDecl::U32:
m_output << ": u32 := ";
visit(_x.expr());
m_output << " : u32\n";
break;
case TypedVarDecl::U64:
m_output << ": u64 := ";
visit(_x.expr());
m_output << " : u64\n";
break;
case TypedVarDecl::U128:
m_output << ": u128 := ";
visit(_x.expr());
m_output << " : u128\n";
break;
case TypedVarDecl::U256:
m_output << ": u256 := ";
visit(_x.expr());
m_output << " : u256\n";
break;
}
// If we are inside a for-init block, there are two places
// where the visited vardecl may have been defined:
// - directly inside the for-init block
// - inside a block within the for-init block
// In the latter case, we don't scope extend.
if (m_inFunctionDef)
{
// Variables declared directly in for-init block
// are tracked separately because their scope
// extends beyond the block they are defined in
// to the rest of the for-loop statement.
if (m_inForInitScope && m_forInitScopeExtEnabled)
{
yulAssert(
!m_funcForLoopInitVars.empty() && !m_funcForLoopInitVars.back().empty(),
"Proto fuzzer: Invalid operation"
);
m_funcForLoopInitVars.back().back().push_back(varName);
}
else
{
yulAssert(
!m_funcVars.empty() && !m_funcVars.back().empty(),
"Proto fuzzer: Invalid operation"
);
m_funcVars.back().back().push_back(varName);
}
}
else
{
if (m_inForInitScope && m_forInitScopeExtEnabled)
{
yulAssert(
!m_globalForLoopInitVars.empty(),
"Proto fuzzer: Invalid operation"
);
m_globalForLoopInitVars.back().push_back(varName);
}
else
{
yulAssert(
!m_globalVars.empty(),
"Proto fuzzer: Invalid operation"
);
m_globalVars.back().push_back(varName);
}
}
}
void ProtoConverter::visit(UnaryOp const& _x)
{
UnaryOp_UOp op = _x.op();
// Replace calls to extcodehash on unsupported EVMs with a dictionary
// token.
if (op == UnaryOp::EXTCODEHASH && !m_evmVersion.hasExtCodeHash())
{
m_output << dictionaryToken();
return;
}
// The following instructions may lead to change of EVM state and are hence
// excluded to avoid false positives.
if (
m_filterStatefulInstructions &&
(
op == UnaryOp::EXTCODEHASH ||
op == UnaryOp::EXTCODESIZE ||
op == UnaryOp::BALANCE ||
op == UnaryOp::BLOCKHASH
)
)
{
m_output << dictionaryToken();
return;
}
switch (op)
{
case UnaryOp::NOT:
m_output << "not";
break;
case UnaryOp::MLOAD:
m_output << "mload";
break;
case UnaryOp::SLOAD:
m_output << "sload";
break;
case UnaryOp::ISZERO:
m_output << "iszero";
break;
case UnaryOp::CALLDATALOAD:
m_output << "calldataload";
break;
case UnaryOp::EXTCODESIZE:
m_output << "extcodesize";
break;
case UnaryOp::EXTCODEHASH:
m_output << "extcodehash";
break;
case UnaryOp::BALANCE:
m_output << "balance";
break;
case UnaryOp::BLOCKHASH:
m_output << "blockhash";
break;
}
m_output << "(";
visit(_x.operand());
m_output << ")";
}
void ProtoConverter::visit(TernaryOp const& _x)
{
switch (_x.op())
{
case TernaryOp::ADDM:
m_output << "addmod";
break;
case TernaryOp::MULM:
m_output << "mulmod";
break;
}
m_output << "(";
visit(_x.arg1());
m_output << ", ";
visit(_x.arg2());
m_output << ", ";
visit(_x.arg3());
m_output << ")";
}
void ProtoConverter::visit(NullaryOp const& _x)
{
auto op = _x.op();
// The following instructions may lead to a change in EVM state and are
// excluded to avoid false positive reports.
if (
m_filterStatefulInstructions &&
(
op == NullaryOp::GAS ||
op == NullaryOp::CODESIZE ||
op == NullaryOp::ADDRESS ||
op == NullaryOp::TIMESTAMP ||
op == NullaryOp::NUMBER ||
op == NullaryOp::DIFFICULTY
)
)
{
m_output << dictionaryToken();
return;
}
switch (op)
{
case NullaryOp::MSIZE:
m_output << "msize()";
break;
case NullaryOp::GAS:
m_output << "gas()";
break;
case NullaryOp::CALLDATASIZE:
m_output << "calldatasize()";
break;
case NullaryOp::CODESIZE:
m_output << "codesize()";
break;
case NullaryOp::RETURNDATASIZE:
// If evm supports returndatasize, we generate it. Otherwise,
// we output a dictionary token.
if (m_evmVersion.supportsReturndata())
m_output << "returndatasize()";
else
m_output << dictionaryToken();
break;
case NullaryOp::ADDRESS:
m_output << "address()";
break;
case NullaryOp::ORIGIN:
m_output << "origin()";
break;
case NullaryOp::CALLER:
m_output << "caller()";
break;
case NullaryOp::CALLVALUE:
m_output << "callvalue()";
break;
case NullaryOp::GASPRICE:
m_output << "gasprice()";
break;
case NullaryOp::COINBASE:
m_output << "coinbase()";
break;
case NullaryOp::TIMESTAMP:
m_output << "timestamp()";
break;
case NullaryOp::NUMBER:
m_output << "number()";
break;
case NullaryOp::DIFFICULTY:
m_output << "difficulty()";
break;
case NullaryOp::GASLIMIT:
m_output << "gaslimit()";
break;
case NullaryOp::SELFBALANCE:
// Replace calls to selfbalance() on unsupported EVMs with a dictionary
// token.
if (m_evmVersion.hasSelfBalance())
m_output << "selfbalance()";
else
m_output << dictionaryToken();
break;
case NullaryOp::CHAINID:
// Replace calls to chainid() on unsupported EVMs with a dictionary
// token.
if (m_evmVersion.hasChainID())
m_output << "chainid()";
else
m_output << dictionaryToken();
break;
}
}
void ProtoConverter::visit(CopyFunc const& _x)
{
CopyFunc_CopyType type = _x.ct();
// datacopy() is valid only if we are inside
// a Yul object.
if (type == CopyFunc::DATA && !m_isObject)
return;
// We don't generate code if the copy function is returndatacopy
// and the underlying evm does not support it.
if (type == CopyFunc::RETURNDATA && !m_evmVersion.supportsReturndata())
return;
// Code copy may change state if e.g., some byte of code
// is stored to storage via a sequence of mload and sstore.
if (m_filterStatefulInstructions && type == CopyFunc::CODE)
return;
switch (type)
{
case CopyFunc::CALLDATA:
m_output << "calldatacopy";
break;
case CopyFunc::CODE:
m_output << "codecopy";
break;
case CopyFunc::RETURNDATA:
yulAssert(m_evmVersion.supportsReturndata(), "Proto fuzzer: Invalid evm version");
m_output << "returndatacopy";
break;
case CopyFunc::DATA:
m_output << "datacopy";
break;
}
m_output << "(";
visit(_x.target());
m_output << ", ";
visit(_x.source());
m_output << ", ";
visit(_x.size());
m_output << ")\n";
}
void ProtoConverter::visit(ExtCodeCopy const& _x)
{
m_output << "extcodecopy";
m_output << "(";
visit(_x.addr());
m_output << ", ";
visit(_x.target());
m_output << ", ";
visit(_x.source());
m_output << ", ";
visit(_x.size());
m_output << ")\n";
}
void ProtoConverter::visit(LogFunc const& _x)
{
switch (_x.num_topics())
{
case LogFunc::ZERO:
m_output << "log0";
m_output << "(";
visit(_x.pos());
m_output << ", ";
visit(_x.size());
m_output << ")\n";
break;
case LogFunc::ONE:
m_output << "log1";
m_output << "(";
visit(_x.pos());
m_output << ", ";
visit(_x.size());
m_output << ", ";
visit(_x.t1());
m_output << ")\n";
break;
case LogFunc::TWO:
m_output << "log2";
m_output << "(";
visit(_x.pos());
m_output << ", ";
visit(_x.size());
m_output << ", ";
visit(_x.t1());
m_output << ", ";
visit(_x.t2());
m_output << ")\n";
break;
case LogFunc::THREE:
m_output << "log3";
m_output << "(";
visit(_x.pos());
m_output << ", ";
visit(_x.size());
m_output << ", ";
visit(_x.t1());
m_output << ", ";
visit(_x.t2());
m_output << ", ";
visit(_x.t3());
m_output << ")\n";
break;
case LogFunc::FOUR:
m_output << "log4";
m_output << "(";
visit(_x.pos());
m_output << ", ";
visit(_x.size());
m_output << ", ";
visit(_x.t1());
m_output << ", ";
visit(_x.t2());
m_output << ", ";
visit(_x.t3());
m_output << ", ";
visit(_x.t4());
m_output << ")\n";
break;
}
}
void ProtoConverter::visit(AssignmentStatement const& _x)
{
visit(_x.ref_id());
m_output << " := ";
visit(_x.expr());
m_output << "\n";
}
void ProtoConverter::visitFunctionInputParams(FunctionCall const& _x, unsigned _numInputParams)
{
// We reverse the order of function input visits since it helps keep this switch case concise.
switch (_numInputParams)
{
case 4:
visit(_x.in_param4());
m_output << ", ";
[[fallthrough]];
case 3:
visit(_x.in_param3());
m_output << ", ";
[[fallthrough]];
case 2:
visit(_x.in_param2());
m_output << ", ";
[[fallthrough]];
case 1:
visit(_x.in_param1());
[[fallthrough]];
case 0:
break;
default:
yulAssert(false, "Proto fuzzer: Function call with too many input parameters.");
break;
}
}
bool ProtoConverter::functionValid(FunctionCall_Returns _type, unsigned _numOutParams)
{
switch (_type)
{
case FunctionCall::ZERO:
return _numOutParams == 0;
case FunctionCall::SINGLE:
return _numOutParams == 1;
case FunctionCall::MULTIDECL:
case FunctionCall::MULTIASSIGN:
return _numOutParams > 1;
}
}
void ProtoConverter::convertFunctionCall(
FunctionCall const& _x,
string const& _name,
unsigned _numInParams,
bool _newLine
)
{
m_output << _name << "(";
visitFunctionInputParams(_x, _numInParams);
m_output << ")";
if (_newLine)
m_output << "\n";
}
vector<string> ProtoConverter::createVarDecls(unsigned _start, unsigned _end, bool _isAssignment)
{
m_output << "let ";
vector<string> varsVec = createVars(_start, _end);
if (_isAssignment)
m_output << " := ";
else
m_output << "\n";
return varsVec;
}
void ProtoConverter::visit(FunctionCall const& _x)
{
bool functionAvailable = m_functionSigMap.size() > 0;
unsigned numInParams, numOutParams;
string funcName;
FunctionCall_Returns funcType = _x.ret();
if (functionAvailable)
{
yulAssert(m_functions.size() > 0, "Proto fuzzer: No function in scope");
funcName = m_functions[_x.func_index() % m_functions.size()];
auto ret = m_functionSigMap.at(funcName);
numInParams = ret.first;
numOutParams = ret.second;
}
else
{
// If there are no functions available, calls to functions that
// return a single value may be replaced by a dictionary token.
if (funcType == FunctionCall::SINGLE)
m_output << dictionaryToken();
return;
}
// If function selected for function call does not meet interface
// requirements (num output values) for the function type
// specified, then we return early unless it is a function call
// that returns a single value (which may be replaced by a
// dictionary token.
if (!functionValid(funcType, numOutParams))
{
if (funcType == FunctionCall::SINGLE)
m_output << dictionaryToken();
return;
}
// If we are here, it means that we have at least one valid
// function for making the function call
switch (funcType)
{
case FunctionCall::ZERO:
convertFunctionCall(_x, funcName, numInParams);
break;
case FunctionCall::SINGLE:
// Since functions that return a single value are used as expressions
// we do not print a newline because it is done by the expression
// visitor.
convertFunctionCall(_x, funcName, numInParams, /*newLine=*/false);
break;
case FunctionCall::MULTIDECL:
{
// Ensure that the chosen function returns at most 4 values
yulAssert(
numOutParams <= 4,
"Proto fuzzer: Function call with too many output params encountered."
);
// Obtain variable name suffix
unsigned startIdx = counter();
vector<string> varsVec = createVarDecls(
startIdx,
startIdx + numOutParams,
/*isAssignment=*/true
);
// Create RHS of multi var decl
convertFunctionCall(_x, funcName, numInParams);
// Add newly minted vars in the multidecl statement to current scope
addVarsToScope(varsVec);
break;
}
case FunctionCall::MULTIASSIGN:
// Ensure that the chosen function returns at most 4 values
yulAssert(
numOutParams <= 4,
"Proto fuzzer: Function call with too many output params encountered."
);
// Return early if numOutParams > number of available variables
if (numOutParams > numVarsInScope())
return;
// Copy variables in scope in order to prevent repeated references
vector<string> variables;
if (m_inFunctionDef)
for (auto var: m_currentFuncVars)
variables.push_back(*var);
else
for (auto var: m_currentGlobalVars)
variables.push_back(*var);
auto refVar = [](vector<string>& _var, unsigned _rand, bool _comma = true) -> string
{
auto index = _rand % _var.size();
string ref = _var[index];
_var.erase(_var.begin() + index);
if (_comma)
ref += ", ";
return ref;
};
// Convert LHS of multi assignment
// We reverse the order of out param visits since the order does not matter.
// This helps reduce the size of this switch statement.
switch (numOutParams)
{
case 4:
m_output << refVar(variables, _x.out_param4().varnum());
[[fallthrough]];
case 3:
m_output << refVar(variables, _x.out_param3().varnum());
[[fallthrough]];
case 2:
m_output << refVar(variables, _x.out_param2().varnum());
m_output << refVar(variables, _x.out_param1().varnum(), false);
break;
default:
yulAssert(false, "Proto fuzzer: Function call with too many or too few input parameters.");
break;
}
m_output << " := ";
// Convert RHS of multi assignment
convertFunctionCall(_x, funcName, numInParams);
break;
}
}
void ProtoConverter::visit(LowLevelCall const& _x)
{
LowLevelCall_Type type = _x.callty();
// Generate staticcall if it is supported by the underlying evm
if (type == LowLevelCall::STATICCALL && !m_evmVersion.hasStaticCall())
{
// Since staticcall is supposed to return 0 on success and 1 on
// failure, we can use counter value to emulate it
m_output << ((counter() % 2) ? "0" : "1");
return;
}
switch (type)
{
case LowLevelCall::CALL:
m_output << "call(";
break;
case LowLevelCall::CALLCODE:
m_output << "callcode(";
break;
case LowLevelCall::DELEGATECALL:
m_output << "delegatecall(";
break;
case LowLevelCall::STATICCALL:
yulAssert(m_evmVersion.hasStaticCall(), "Proto fuzzer: Invalid evm version");
m_output << "staticcall(";
break;
}
visit(_x.gas());
m_output << ", ";
visit(_x.addr());
m_output << ", ";
if (type == LowLevelCall::CALL || type == LowLevelCall::CALLCODE)
{
visit(_x.wei());
m_output << ", ";
}
visit(_x.in());
m_output << ", ";
visit(_x.insize());
m_output << ", ";
visit(_x.out());
m_output << ", ";
visit(_x.outsize());
m_output << ")";
}
void ProtoConverter::visit(Create const& _x)
{
Create_Type type = _x.createty();
// Replace a call to create2 on unsupported EVMs with a dictionary
// token.
if (type == Create::CREATE2 && !m_evmVersion.hasCreate2())
{
m_output << dictionaryToken();
return;
}
switch (type)
{
case Create::CREATE:
m_output << "create(";
break;
case Create::CREATE2:
m_output << "create2(";
break;
}
visit(_x.wei());
m_output << ", ";
visit(_x.position());
m_output << ", ";
visit(_x.size());
if (type == Create::CREATE2)
{
m_output << ", ";
visit(_x.value());
}
m_output << ")";
}
void ProtoConverter::visit(IfStmt const& _x)
{
m_output << "if ";
visit(_x.cond());
m_output << " ";
visit(_x.if_body());
}
void ProtoConverter::visit(StoreFunc const& _x)
{
switch (_x.st())
{
case StoreFunc::MSTORE:
m_output << "mstore(";
break;
case StoreFunc::SSTORE:
m_output << "sstore(";
break;
case StoreFunc::MSTORE8:
m_output << "mstore8(";
break;
}
visit(_x.loc());
m_output << ", ";
visit(_x.val());
m_output << ")\n";
}
void ProtoConverter::visit(ForStmt const& _x)
{
if (++m_numForLoops > s_maxForLoops)
return;
bool wasInForBody = m_inForBodyScope;
bool wasInForInit = m_inForInitScope;
bool wasForInitScopeExtEnabled = m_forInitScopeExtEnabled;
m_inForBodyScope = false;
m_inForInitScope = true;
m_forInitScopeExtEnabled = true;
m_inForCond = false;
m_output << "for ";
visit(_x.for_init());
m_inForInitScope = false;
m_forInitScopeExtEnabled = wasForInitScopeExtEnabled;
m_inForCond = true;
visit(_x.for_cond());
m_inForCond = false;
visit(_x.for_post());
m_inForBodyScope = true;
visit(_x.for_body());
m_inForBodyScope = wasInForBody;
m_inForInitScope = wasInForInit;
if (m_inFunctionDef)
{
yulAssert(
!m_funcForLoopInitVars.empty() && !m_funcForLoopInitVars.back().empty(),
"Proto fuzzer: Invalid data structure"
);
// Remove variables in for-init
m_funcForLoopInitVars.back().pop_back();
}
else
{
yulAssert(!m_globalForLoopInitVars.empty(), "Proto fuzzer: Invalid data structure");
m_globalForLoopInitVars.pop_back();
}
}
void ProtoConverter::visit(BoundedForStmt const& _x)
{
if (++m_numForLoops > s_maxForLoops)
return;
// Boilerplate for loop that limits the number of iterations to a maximum of 4.
std::string loopVarName("i_" + std::to_string(m_numNestedForLoops++));
m_output << "for { let " << loopVarName << " := 0 } "
<< "lt(" << loopVarName << ", 0x60) "
<< "{ " << loopVarName << " := add(" << loopVarName << ", 0x20) } ";
// Store previous for body scope
bool wasInForBody = m_inForBodyScope;
bool wasInForInit = m_inForInitScope;
m_inForBodyScope = true;
m_inForInitScope = false;
visit(_x.for_body());
// Restore previous for body scope and init
m_inForBodyScope = wasInForBody;
m_inForInitScope = wasInForInit;
}
void ProtoConverter::visit(CaseStmt const& _x)
{
string literal = visit(_x.case_lit());
// u256 value of literal
u256 literalVal;
// Convert string to u256 before looking for duplicate case literals
if (_x.case_lit().has_strval())
{
// Since string literals returned by the Literal visitor are enclosed within
// double quotes (like this "\"<string>\""), their size is at least two in the worst case
// that <string> is empty. Here we assert this invariant.
yulAssert(literal.size() >= 2, "Proto fuzzer: String literal too short");
// This variable stores the <string> part i.e., literal minus the first and last
// double quote characters. This is used to compute the keccak256 hash of the
// string literal. The hashing is done to check whether we are about to create
// a case statement containing a case literal that has already been used in a
// previous case statement. If the hash (u256 value) matches a previous hash,
// then we simply don't create a new case statement.
string noDoubleQuoteStr;
if (literal.size() > 2)
{
// Ensure that all characters in the string literal except the first
// and the last (double quote characters) are alphanumeric.
yulAssert(
boost::algorithm::all_of(literal.begin() + 1, literal.end() - 2, [=](char c) -> bool {
return std::isalpha(c) || std::isdigit(c);
}),
"Proto fuzzer: Invalid string literal encountered"
);
// Make a copy because literal will need to be used later
noDoubleQuoteStr = literal.substr(1, literal.size() - 2);
}
// Hash the result to check for duplicate case literal strings
literalVal = u256(h256(noDoubleQuoteStr, h256::FromBinary, h256::AlignLeft));
// Make sure that an empty string literal evaluates to zero. This is to detect creation of
// duplicate case literals like so
// switch (x)
// {
// case "": { x := 0 }
// case 0: { x:= 1 } // Case statement with duplicate literal is invalid
// } // This snippet will not be parsed successfully.
if (noDoubleQuoteStr.empty())
yulAssert(literalVal == 0, "Proto fuzzer: Empty string does not evaluate to zero");
}
else if (_x.case_lit().has_boolval())
literalVal = _x.case_lit().boolval() ? u256(1) : u256(0);
else
literalVal = u256(literal);
// Check if set insertion fails (case literal present) or succeeds (case literal
// absent).
bool isUnique = m_switchLiteralSetPerScope.top().insert(literalVal).second;
// It is fine to bail out if we encounter a duplicate case literal because
// we can be assured that the switch statement is well-formed i.e., contains
// at least one case statement or a default block.
if (isUnique)
{
m_output << "case " << literal << " ";
visit(_x.case_block());
}
}
void ProtoConverter::visit(SwitchStmt const& _x)
{
if (_x.case_stmt_size() > 0 || _x.has_default_block())
{
std::set<u256> s;
m_switchLiteralSetPerScope.push(s);
m_output << "switch ";
visit(_x.switch_expr());
m_output << "\n";
for (auto const& caseStmt: _x.case_stmt())
visit(caseStmt);
m_switchLiteralSetPerScope.pop();
if (_x.has_default_block())
{
m_output << "default ";
visit(_x.default_block());
}
}
}
void ProtoConverter::visit(StopInvalidStmt const& _x)
{
switch (_x.stmt())
{
case StopInvalidStmt::STOP:
m_output << "stop()\n";
break;
case StopInvalidStmt::INVALID:
m_output << "invalid()\n";
break;
}
}
void ProtoConverter::visit(RetRevStmt const& _x)
{
switch (_x.stmt())
{
case RetRevStmt::RETURN:
m_output << "return";
break;
case RetRevStmt::REVERT:
m_output << "revert";
break;
}
m_output << "(";
visit(_x.pos());
m_output << ", ";
visit(_x.size());
m_output << ")\n";
}
void ProtoConverter::visit(SelfDestructStmt const& _x)
{
m_output << "selfdestruct";
m_output << "(";
visit(_x.addr());
m_output << ")\n";
}
void ProtoConverter::visit(TerminatingStmt const& _x)
{
switch (_x.term_oneof_case())
{
case TerminatingStmt::kStopInvalid:
visit(_x.stop_invalid());
break;
case TerminatingStmt::kRetRev:
visit(_x.ret_rev());
break;
case TerminatingStmt::kSelfDes:
visit(_x.self_des());
break;
case TerminatingStmt::TERM_ONEOF_NOT_SET:
break;
}
}
void ProtoConverter::visit(UnaryOpData const& _x)
{
switch (_x.op())
{
case UnaryOpData::SIZE:
m_output << Whiskers(R"(datasize("<id>"))")
("id", getObjectIdentifier(static_cast<unsigned>(_x.identifier())))
.render();
break;
case UnaryOpData::OFFSET:
m_output << Whiskers(R"(dataoffset("<id>"))")
("id", getObjectIdentifier(static_cast<unsigned>(_x.identifier())))
.render();
break;
}
}
void ProtoConverter::visit(Statement const& _x)
{
switch (_x.stmt_oneof_case())
{
case Statement::kDecl:
visit(_x.decl());
break;
case Statement::kAssignment:
// Create an assignment statement only if there is at least one variable
// declaration that is in scope.
if (varDeclAvailable())
visit(_x.assignment());
break;
case Statement::kIfstmt:
if (_x.ifstmt().if_body().statements_size() > 0)
visit(_x.ifstmt());
break;
case Statement::kStorageFunc:
visit(_x.storage_func());
break;
case Statement::kBlockstmt:
if (_x.blockstmt().statements_size() > 0)
visit(_x.blockstmt());
break;
case Statement::kForstmt:
if (_x.forstmt().for_body().statements_size() > 0 && !m_filterUnboundedLoops)
visit(_x.forstmt());
break;
case Statement::kBoundedforstmt:
if (_x.boundedforstmt().for_body().statements_size() > 0)
visit(_x.boundedforstmt());
break;
case Statement::kSwitchstmt:
visit(_x.switchstmt());
break;
case Statement::kBreakstmt:
if (m_inForBodyScope)
m_output << "break\n";
break;
case Statement::kContstmt:
if (m_inForBodyScope)
m_output << "continue\n";
break;
case Statement::kLogFunc:
visit(_x.log_func());
break;
case Statement::kCopyFunc:
visit(_x.copy_func());
break;
case Statement::kExtcodeCopy:
// Extcodecopy may change state if external code is copied via a
// sequence of mload/sstore.
if (!m_filterStatefulInstructions)
visit(_x.extcode_copy());
break;
case Statement::kTerminatestmt:
visit(_x.terminatestmt());
break;
case Statement::kFunctioncall:
// Return early if a function call cannot be created
if (functionCallNotPossible(_x.functioncall().ret()))
return;
visit(_x.functioncall());
break;
case Statement::kFuncdef:
if (_x.funcdef().block().statements_size() > 0)
if (!m_inForInitScope)
visit(_x.funcdef());
break;
case Statement::kPop:
visit(_x.pop());
break;
case Statement::kLeave:
if (m_inFunctionDef)
visit(_x.leave());
break;
case Statement::kMultidecl:
visit(_x.multidecl());
break;
case Statement::STMT_ONEOF_NOT_SET:
break;
}
}
void ProtoConverter::openBlockScope()
{
m_scopeFuncs.emplace_back(vector<string>{});
// Create new block scope inside current function scope
if (m_inFunctionDef)
{
yulAssert(
!m_funcVars.empty(),
"Proto fuzzer: Invalid data structure"
);
m_funcVars.back().push_back(vector<string>{});
if (m_inForInitScope && m_forInitScopeExtEnabled)
{
yulAssert(
!m_funcForLoopInitVars.empty(),
"Proto fuzzer: Invalid data structure"
);
m_funcForLoopInitVars.back().push_back(vector<string>{});
}
}
else
{
m_globalVars.emplace_back(vector<string>{});
if (m_inForInitScope && m_forInitScopeExtEnabled)
m_globalForLoopInitVars.emplace_back(vector<string>{});
}
}
void ProtoConverter::openFunctionScope(vector<string> const& _funcParams)
{
m_funcVars.push_back(vector<vector<string>>({_funcParams}));
m_funcForLoopInitVars.push_back(vector<vector<string>>({}));
}
void ProtoConverter::updateFunctionMaps(string const& _var)
{
size_t erased = m_functionSigMap.erase(_var);
for (auto const& i: m_functionDefMap)
if (i.second == _var)
{
erased += m_functionDefMap.erase(i.first);
break;
}
yulAssert(erased == 2, "Proto fuzzer: Function maps not updated");
}
void ProtoConverter::closeBlockScope()
{
// Remove functions declared in the block that is going
// out of scope from the global function map.
for (auto const& f: m_scopeFuncs.back())
{
size_t numFuncsRemoved = m_functions.size();
m_functions.erase(remove(m_functions.begin(), m_functions.end(), f), m_functions.end());
numFuncsRemoved -= m_functions.size();
yulAssert(
numFuncsRemoved == 1,
"Proto fuzzer: Nothing or too much went out of scope"
);
updateFunctionMaps(f);
}
// Pop back the vector of scoped functions.
if (!m_scopeFuncs.empty())
m_scopeFuncs.pop_back();
// If block belongs to function body, then remove
// local variables in function body that are going out of scope.
if (m_inFunctionDef)
{
yulAssert(!m_funcVars.empty(), "Proto fuzzer: Invalid data structure");
if (!m_funcVars.back().empty())
m_funcVars.back().pop_back();
}
// Remove variables declared in vanilla block from current
// global scope.
else
{
yulAssert(!m_globalVars.empty(), "Proto fuzzer: Invalid data structure");
m_globalVars.pop_back();
}
}
void ProtoConverter::closeFunctionScope()
{
yulAssert(!m_funcVars.empty(), "Proto fuzzer: Invalid data structure");
m_funcVars.pop_back();
yulAssert(!m_funcForLoopInitVars.empty(), "Proto fuzzer: Invalid data structure");
m_funcForLoopInitVars.pop_back();
}
void ProtoConverter::addVarsToScope(vector<string> const& _vars)
{
// If we are in function definition, add the new vars to current function scope
if (m_inFunctionDef)
{
// If we are directly in for-init block, add the newly created vars to the
// stack of for-init variables.
if (m_inForInitScope && m_forInitScopeExtEnabled)
{
yulAssert(
!m_funcForLoopInitVars.empty() && !m_funcForLoopInitVars.back().empty(),
"Proto fuzzer: Invalid data structure"
);
m_funcForLoopInitVars.back().back().insert(
m_funcForLoopInitVars.back().back().end(),
_vars.begin(),
_vars.end()
);
}
else
{
yulAssert(
!m_funcVars.empty() && !m_funcVars.back().empty(),
"Proto fuzzer: Invalid data structure"
);
m_funcVars.back().back().insert(
m_funcVars.back().back().end(),
_vars.begin(),
_vars.end()
);
}
}
// If we are in a vanilla block, add the new vars to current global scope
else
{
if (m_inForInitScope && m_forInitScopeExtEnabled)
{
yulAssert(
!m_globalForLoopInitVars.empty(),
"Proto fuzzer: Invalid data structure"
);
m_globalForLoopInitVars.back().insert(
m_globalForLoopInitVars.back().end(),
_vars.begin(),
_vars.end()
);
}
else
{
yulAssert(
!m_globalVars.empty(),
"Proto fuzzer: Invalid data structure"
);
m_globalVars.back().insert(
m_globalVars.back().end(),
_vars.begin(),
_vars.end()
);
}
}
}
void ProtoConverter::visit(Block const& _x)
{
openBlockScope();
// Register function declarations in this scope unless this
// scope belongs to for-init (in which function declarations
// are forbidden).
for (auto const& statement: _x.statements())
if (statement.has_funcdef() && statement.funcdef().block().statements_size() > 0 && !m_inForInitScope)
registerFunction(&statement.funcdef());
if (_x.statements_size() > 0)
{
m_output << "{\n";
bool wasForInitScopeExtEnabled = m_forInitScopeExtEnabled;
for (auto const& st: _x.statements())
{
// If statement is block or introduces one and we are in for-init block
// then temporarily disable scope extension if it is not already disabled.
if (
(st.has_blockstmt() || st.has_switchstmt() || st.has_ifstmt()) &&
m_inForInitScope &&
m_forInitScopeExtEnabled
)
m_forInitScopeExtEnabled = false;
visit(st);
m_forInitScopeExtEnabled = wasForInitScopeExtEnabled;
}
m_output << "}\n";
}
else
m_output << "{}\n";
closeBlockScope();
}
vector<string> ProtoConverter::createVars(unsigned _startIdx, unsigned _endIdx)
{
yulAssert(_endIdx > _startIdx, "Proto fuzzer: Variable indices not in range");
string varsStr = suffixedVariableNameList("x_", _startIdx, _endIdx);
m_output << varsStr;
vector<string> varsVec;
boost::split(
varsVec,
varsStr,
boost::algorithm::is_any_of(", "),
boost::algorithm::token_compress_on
);
yulAssert(
varsVec.size() == (_endIdx - _startIdx),
"Proto fuzzer: Variable count mismatch during function definition"
);
m_counter += varsVec.size();
return varsVec;
}
void ProtoConverter::registerFunction(FunctionDef const* _x)
{
unsigned numInParams = _x->num_input_params() % s_modInputParams;
unsigned numOutParams = _x->num_output_params() % s_modOutputParams;
NumFunctionReturns numReturns;
if (numOutParams == 0)
numReturns = NumFunctionReturns::None;
else if (numOutParams == 1)
numReturns = NumFunctionReturns::Single;
else
numReturns = NumFunctionReturns::Multiple;
// Generate function name
string funcName = functionName(numReturns);
// Register function
auto ret = m_functionSigMap.emplace(make_pair(funcName, make_pair(numInParams, numOutParams)));
yulAssert(ret.second, "Proto fuzzer: Function already exists.");
m_functions.push_back(funcName);
m_scopeFuncs.back().push_back(funcName);
m_functionDefMap.emplace(make_pair(_x, funcName));
}
void ProtoConverter::fillFunctionCallInput(unsigned _numInParams)
{
for (unsigned i = 0; i < _numInParams; i++)
{
// Throw a 4-sided dice to choose whether to populate function input
// argument from a pseudo-randomly chosen slot in one of the following
// locations: calldata, memory, storage, or Yul optimizer dictionary.
unsigned diceValue = counter() % 4;
// Pseudo-randomly choose one of the first ten 32-byte
// aligned slots.
string slot = to_string((counter() % 10) * 32);
switch (diceValue)
{
case 0:
m_output << "calldataload(" << slot << ")";
break;
case 1:
m_output << "mload(" << slot << ")";
break;
case 2:
m_output << "sload(" << slot << ")";
break;
default:
// Call to dictionaryToken() automatically picks a token
// at a pseudo-random location.
m_output << dictionaryToken();
break;
}
if (i < _numInParams - 1)
m_output << ",";
}
}
void ProtoConverter::saveFunctionCallOutput(vector<string> const& _varsVec)
{
for (auto const& var: _varsVec)
{
// Flip a dice to choose whether to save output values
// in storage or memory.
bool coinFlip = counter() % 2 == 0;
// Pseudo-randomly choose one of the first ten 32-byte
// aligned slots.
string slot = to_string((counter() % 10) * 32);
if (coinFlip)
m_output << "sstore(" << slot << ", " << var << ")\n";
else
m_output << "mstore(" << slot << ", " << var << ")\n";
}
}
void ProtoConverter::createFunctionCall(
string const& _funcName,
unsigned _numInParams,
unsigned _numOutParams
)
{
vector<string> varsVec{};
if (_numOutParams > 0)
{
unsigned startIdx = counter();
// Prints the following to output stream "let x_i,...,x_n := "
varsVec = createVarDecls(
startIdx,
startIdx + _numOutParams,
/*isAssignment=*/true
);
}
// Call the function with the correct number of input parameters
m_output << _funcName << "(";
if (_numInParams > 0)
fillFunctionCallInput(_numInParams);
m_output << ")\n";
if (!varsVec.empty())
{
// Save values returned by function so that they are reflected
// in the interpreter trace.
saveFunctionCallOutput(varsVec);
// Add newly minted vars to current scope
addVarsToScope(varsVec);
}
else
yulAssert(_numOutParams == 0, "Proto fuzzer: Function return value not saved");
}
void ProtoConverter::createFunctionDefAndCall(
FunctionDef const& _x,
unsigned _numInParams,
unsigned _numOutParams
)
{
yulAssert(
((_numInParams <= s_modInputParams - 1) && (_numOutParams <= s_modOutputParams - 1)),
"Proto fuzzer: Too many function I/O parameters requested."
);
// Obtain function name
yulAssert(m_functionDefMap.count(&_x), "Proto fuzzer: Unregistered function");
string funcName = m_functionDefMap.at(&_x);
vector<string> varsVec = {};
m_output << "function " << funcName << "(";
unsigned startIdx = counter();
if (_numInParams > 0)
varsVec = createVars(startIdx, startIdx + _numInParams);
m_output << ")";
vector<string> outVarsVec = {};
// This creates -> x_n+1,...,x_r
if (_numOutParams > 0)
{
m_output << " -> ";
if (varsVec.empty())
{
yulAssert(_numInParams == 0, "Proto fuzzer: Input parameters not processed correctly");
varsVec = createVars(startIdx, startIdx + _numOutParams);
}
else
{
outVarsVec = createVars(startIdx + _numInParams, startIdx + _numInParams + _numOutParams);
varsVec.insert(varsVec.end(), outVarsVec.begin(), outVarsVec.end());
}
}
yulAssert(varsVec.size() == _numInParams + _numOutParams, "Proto fuzzer: Function parameters not processed correctly");
m_output << "\n";
// If function definition is in for-loop body, update
bool wasInForBody = m_inForBodyScope;
m_inForBodyScope = false;
bool wasInFunctionDef = m_inFunctionDef;
m_inFunctionDef = true;
// Create new function scope and add function input and return
// parameters to it.
openFunctionScope(varsVec);
// Visit function body
visit(_x.block());
closeFunctionScope();
m_inForBodyScope = wasInForBody;
m_inFunctionDef = wasInFunctionDef;
yulAssert(
!m_inForInitScope,
"Proto fuzzer: Trying to create function call inside a for-init block"
);
if (_x.force_call())
createFunctionCall(funcName, _numInParams, _numOutParams);
}
void ProtoConverter::visit(FunctionDef const& _x)
{
unsigned numInParams = _x.num_input_params() % s_modInputParams;
unsigned numOutParams = _x.num_output_params() % s_modOutputParams;
createFunctionDefAndCall(_x, numInParams, numOutParams);
}
void ProtoConverter::visit(PopStmt const& _x)
{
m_output << "pop(";
visit(_x.expr());
m_output << ")\n";
}
void ProtoConverter::visit(LeaveStmt const&)
{
m_output << "leave\n";
}
string ProtoConverter::getObjectIdentifier(unsigned _x)
{
unsigned currentId = currentObjectId();
string currentObjName = "object" + to_string(currentId);
yulAssert(
m_objectScope.count(currentObjName) && !m_objectScope.at(currentObjName).empty(),
"Yul proto fuzzer: Error referencing object"
);
vector<string> objectIdsInScope = m_objectScope.at(currentObjName);
return objectIdsInScope[_x % objectIdsInScope.size()];
}
void ProtoConverter::visit(Code const& _x)
{
m_output << "code {\n";
visit(_x.block());
m_output << "}\n";
}
void ProtoConverter::visit(Data const& _x)
{
// TODO: Generate random data block identifier
m_output << "data \"" << s_dataIdentifier << "\" hex\"" << createHex(_x.hex()) << "\"\n";
}
void ProtoConverter::visit(Object const& _x)
{
// object "object<n>" {
// ...
// }
m_output << "object " << newObjectId() << " {\n";
visit(_x.code());
if (_x.has_data())
visit(_x.data());
for (auto const& subObj: _x.sub_obj())
visit(subObj);
m_output << "}\n";
}
void ProtoConverter::buildObjectScopeTree(Object const& _x)
{
// Identifies object being visited
string objectName = newObjectId(false);
vector<string> node{objectName};
if (_x.has_data())
node.emplace_back(s_dataIdentifier);
for (auto const& subObj: _x.sub_obj())
{
// Identifies sub object whose numeric suffix is
// m_objectId
unsigned subObjectId = m_objectId;
string subObjectName = "object" + to_string(subObjectId);
node.push_back(subObjectName);
buildObjectScopeTree(subObj);
// Add sub-object to object's ancestors
yulAssert(m_objectScope.count(subObjectName), "Yul proto fuzzer: Invalid object hierarchy");
for (string const& item: m_objectScope.at(subObjectName))
if (item != subObjectName)
node.emplace_back(subObjectName + "." + item);
}
m_objectScope.emplace(objectName, node);
}
void ProtoConverter::visit(Program const& _x)
{
// Initialize input size
m_inputSize = static_cast<unsigned>(_x.ByteSizeLong());
// Record EVM Version
m_evmVersion = evmVersionMapping(_x.ver());
// Program is either a Yul object or a block of
// statements.
switch (_x.program_oneof_case())
{
case Program::kBlock:
m_output << "{\n";
visit(_x.block());
m_output << "}\n";
break;
case Program::kObj:
m_isObject = true;
buildObjectScopeTree(_x.obj());
// Reset object id counter
m_objectId = 0;
visit(_x.obj());
break;
case Program::PROGRAM_ONEOF_NOT_SET:
// {} is a trivial Yul program
m_output << "{}";
break;
}
}
string ProtoConverter::programToString(Program const& _input)
{
visit(_input);
return m_output.str();
}
string ProtoConverter::functionTypeToString(NumFunctionReturns _type)
{
switch (_type)
{
case NumFunctionReturns::None:
return "n";
case NumFunctionReturns::Single:
return "s";
case NumFunctionReturns::Multiple:
return "m";
}
}