Method initMemory

lib/executor/instantiate/data.cpp:60–96

Initialize memory with Data section. See "include/executor/executor.h".

// Initialize memory with Data section. See "include/executor/executor.h".
Expect<void> Executor::initMemory(Runtime::StackManager &StackMgr,
                                  const AST::DataSection &DataSec) {
  // Initialize memory.
  uint32_t Idx = 0;
  for (const auto &DataSeg : DataSec.getContent()) {
    // Initialize memory if data mode is active.
    if (DataSeg.getMode() == AST::DataSegment::DataMode::Active) {
      // Memory and data indices are checked in the validation phase.
      auto *MemInst = getMemInstByIdx(StackMgr, DataSeg.getIdx());
      assuming(MemInst);
      auto *DataInst = getDataInstByIdx(StackMgr, Idx);
      assuming(DataInst);
      const uint64_t Off = DataInst->getOffset();

      // Replace mem[Off : Off + n] with data[0 : n].
      EXPECTED_TRY(MemInst
                       ->setBytes(DataInst->getData(), Off, 0,
                                  DataInst->getData().size())
                       .map_error([](auto E) {
                         spdlog::error(ErrInfo::InfoAST(ASTNodeAttr::Seg_Data));
                         return E;
                       }));

      // Drop the data instance.
      DataInst->clear();

      // Operation above is equal to the following instruction sequence:
      //   expr(init) -> i32.const off
      //   i32.const 0
      //   i32.const n
      //   memory.init idx
      //   data.drop idx
    }
    Idx++;
  }
  return {};
}

} // namespace Executor
} // namespace WasmEdge