ScillaExecImpl.h

/*
 * Copyright (C) 2021 Zilliqa
 *
 * This program 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.
 *
 * This program 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 this program.  If not, see <https://www.gnu.org/licenses/>.
 */

#include <json/json.h>
#include <memory>

#include "ObjManager.h"
#include "ScillaRTL/ScillaExec.h"

namespace ScillaRTL {

class SharedObject;
class TransitionState;

class ScillaExecImpl {
private:
  void initContrParams(const Json::Value &CP, bool DoDynamicTypechecks);
  std::unique_ptr<ScillaTypes::TypParserPartialCache> TPPC;
  // Get the type descriptors table and its length.
  std::pair<const ScillaTypes::Typ **, int> getTypeDescrTable() const;
  const std::unique_ptr<SharedObject> SO;
  uint64_t *const GasRemPtr;
  friend bool dynamicTypecheck(const ScillaExecImpl *SJ,
                               const ScillaTypes::Typ *TargetT,
                               const ScillaTypes::Typ *ParsedT, const void *Val,
                               bool ChargeGas);

public:
  // @ContrBin is the path to a contract's shared object `foo.so`
  // generated by compiling `foo.scilla` with scilla-llvm into `foo.bc`
  // and compiling this LLVM bitcode with `clang -shared foo.bc -o foo.so`.
  ScillaExecImpl(const ScillaParams &SPs, const std::string &ContrBin);
  ~ScillaExecImpl();

  // Get address for @Symbol inside the compiled IR, ready to be used.
  void *getAddressFor(const std::string &Symbol) const;
  // Initialize gas-remaining field in the code and initialize libraries.
  void initGasAndLibs(uint64_t GasRem);
  // Execute a message.
  Json::Value execMsg(const std::string &Balance, uint64_t GasLimit,
                      const Json::Value &InitJ, const Json::Value &Msg);
  // Initialize the contract state to field initialization values in the source.
  // This is to be called only during deployment of the contract. Never again.
  Json::Value deploy(const Json::Value &InitJ, uint64_t GasLimit);
  // What's the gas remaining from previous execution (deploy / execMsg).
  // Useful if execution was interrupted due to an exception.
  // Use with care if you don't want to end up with a stale value.
  uint64_t getGasRem() const;
  // Parse a string into a Scilla type. Raises error on failure.
  const ScillaTypes::Typ *parseTypeString(const std::string &) const;
  // Raise an out-of-gas exception.
  static void outOfGasException(void);
  // Consume N units of gas. Raise an error if we're out of gas.
  void consumeGas(uint64_t N) const;

  // Scilla values dynamically allocated and owned by the JIT engine.
  ObjManager OM;
  // Scilla configuration parameters.
  const ScillaParams SPs;
  // The state of execution specific to a transition.
  std::unique_ptr<TransitionState> TS;
  // If the Scilla code wants to print something, that goes here.
  std::string ScillaStdout;
};

} // namespace ScillaRTL