bool WasmBase::load()

in plugins/experimental/wasm/lib/src/wasm.cc [248:324]
60 lines of code
15 McCabe index (conditional complexity)

bool WasmBase::load(const std::string &code, bool allow_precompiled) {
  assert(!started_from_.has_value());

  if (!wasm_vm_) {
    return false;
  }

  if (wasm_vm_->getEngineName() == "null") {
    auto ok = wasm_vm_->load(code, {}, {});
    if (!ok) {
      fail(FailState::UnableToInitializeCode, "Failed to load NullVM plugin");
      return false;
    }
    abi_version_ = AbiVersion::ProxyWasm_0_2_1;
    return true;
  }

  // Verify signature.
  std::string message;
  if (!SignatureUtil::verifySignature(code, message)) {
    fail(FailState::UnableToInitializeCode, message);
    return false;
  }
  if (!message.empty()) {
    wasm_vm_->integration()->trace(message);
  }

  // Get ABI version from the module.
  if (!BytecodeUtil::getAbiVersion(code, abi_version_)) {
    fail(FailState::UnableToInitializeCode, "Failed to parse corrupted Wasm module");
    return false;
  }
  if (abi_version_ == AbiVersion::Unknown) {
    fail(FailState::UnableToInitializeCode, "Missing or unknown Proxy-Wasm ABI version");
    return false;
  }

  // Get function names from the module.
  if (!BytecodeUtil::getFunctionNameIndex(code, function_names_)) {
    fail(FailState::UnableToInitializeCode, "Failed to parse corrupted Wasm module");
    return false;
  }

  std::string_view precompiled = {};

  if (allow_precompiled) {
    // Check if precompiled module exists.
    const auto section_name = wasm_vm_->getPrecompiledSectionName();
    if (!section_name.empty()) {
      if (!BytecodeUtil::getCustomSection(code, section_name, precompiled)) {
        fail(FailState::UnableToInitializeCode, "Failed to parse corrupted Wasm module");
        return false;
      }
    }
  }

  // Get original bytecode (possibly stripped).
  std::string stripped;
  if (!BytecodeUtil::getStrippedSource(code, stripped)) {
    fail(FailState::UnableToInitializeCode, "Failed to parse corrupted Wasm module");
    return false;
  }

  auto ok = wasm_vm_->load(stripped, precompiled, function_names_);
  if (!ok) {
    fail(FailState::UnableToInitializeCode, "Failed to load Wasm bytecode");
    return false;
  }

  // Store for future use in non-cloneable Wasm engines.
  if (wasm_vm_->cloneable() == Cloneable::NotCloneable) {
    module_bytecode_ = stripped;
    module_precompiled_ = precompiled;
  }

  return true;
}