Function resolveChildInstanceType

lib/validator/component_validator.cpp:165–207

Resolve a type index in `Comp`'s own type index space to an InstanceType. Returns nullptr when the index does not refer to an inline InstanceType definition — callers treat nullptr as "no required shape" and fall back to inferred exports. TypeBound imports and outer-alias type imports currently fall through to nullptr; a more complete resolver would walk the alias chain to recover the underlying I

// currently fall through to nullptr; a more complete resolver would walk
// the alias chain to recover the underlying InstanceType.
const AST::Component::InstanceType *
resolveChildInstanceType(const AST::Component::Component &Comp,
                         uint32_t TypeIdx) {
  uint32_t CurrentIdx = 0;
  for (const auto &Sec : Comp.getSections()) {
    if (std::holds_alternative<AST::Component::TypeSection>(Sec)) {
      const auto &TSec = std::get<AST::Component::TypeSection>(Sec);
      for (const auto &DT : TSec.getContent()) {
        if (CurrentIdx == TypeIdx) {
          if (DT.isInstanceType()) {
            return &DT.getInstanceType();
          }
          return nullptr;
        }
        CurrentIdx++;
      }
    } else if (std::holds_alternative<AST::Component::ImportSection>(Sec)) {
      const auto &ISec = std::get<AST::Component::ImportSection>(Sec);
      for (const auto &Import : ISec.getContent()) {
        if (Import.getDesc().getDescType() ==
            AST::Component::ExternDesc::DescType::TypeBound) {
          if (CurrentIdx == TypeIdx) {
            return nullptr;
          }
          CurrentIdx++;
        }
      }
    } else if (std::holds_alternative<AST::Component::AliasSection>(Sec)) {
      const auto &ASec = std::get<AST::Component::AliasSection>(Sec);
      for (const auto &Alias : ASec.getContent()) {
        if (!Alias.getSort().isCore() &&
            Alias.getSort().getSortType() ==
                AST::Component::Sort::SortType::Type) {
          if (CurrentIdx == TypeIdx) {
            return nullptr;
          }
          CurrentIdx++;
        }
      }
    }
  }
  return nullptr;
}

// Validate that a name may appear at an export position: reject the
// `relative-url=` prefix (not part of the extern-name grammar) and any