Method initTable

lib/executor/instantiate/elem.cpp:73–113

Initialize table with Element section. See "include/executor/executor.h".

// Initialize table with Element section. See "include/executor/executor.h".
Expect<void> Executor::initTable(Runtime::StackManager &StackMgr,
                                 const AST::ElementSection &ElemSec) {
  // Initialize tables.
  uint32_t Idx = 0;
  for (const auto &ElemSeg : ElemSec.getContent()) {
    // Element index is checked in validation phase.
    auto *ElemInst = getElemInstByIdx(StackMgr, Idx);
    assuming(ElemInst);
    if (ElemSeg.getMode() == AST::ElementSegment::ElemMode::Active) {
      // Table index is checked in validation phase.
      auto *TabInst = getTabInstByIdx(StackMgr, ElemSeg.getIdx());
      assuming(TabInst);
      const uint64_t Off = ElemInst->getOffset();

      // Replace table[Off : Off + n] with elem[0 : n].
      EXPECTED_TRY(
          TabInst
              ->setRefs(ElemInst->getRefs(), Off, 0, ElemInst->getRefs().size())
              .map_error([](auto E) {
                spdlog::error(ErrInfo::InfoAST(ASTNodeAttr::Seg_Element));
                return E;
              }));

      // Drop the element instance.
      ElemInst->clear();

      // Operation above is equal to the following instruction sequence:
      //   expr(init) -> i32.const off
      //   i32.const 0
      //   i32.const n
      //   table.init idx
      //   elem.drop idx
    } else if (ElemSeg.getMode() ==
               AST::ElementSegment::ElemMode::Declarative) {
      // Drop the element instance.
      ElemInst->clear();
    }
    Idx++;
  }
  return {};
}

} // namespace Executor
} // namespace WasmEdge