Method getModuleImpl

src/lib/Bitcode/Reader/BitcodeReader.cpp:5856–5895

Get a lazy one-at-time loading module from bitcode. This isn't always used in a lazy context. In particular, it's also used by \a parseModule(). If this is truly lazy, then we need to eagerly pull in forward-referenced functions from block address references. \param[in] MaterializeAll Set to \c true if we should materialize everything.

/// \param[in] MaterializeAll Set to \c true if we should materialize
/// everything.
Expected<std::unique_ptr<Module>>
BitcodeModule::getModuleImpl(LLVMContext &Context, bool MaterializeAll,
                             bool ShouldLazyLoadMetadata, bool IsImporting) {
  BitstreamCursor Stream(Buffer);

  std::string ProducerIdentification;
  if (IdentificationBit != -1ull) {
    Stream.JumpToBit(IdentificationBit);
    Expected<std::string> ProducerIdentificationOrErr =
        readIdentificationBlock(Stream);
    if (!ProducerIdentificationOrErr)
      return ProducerIdentificationOrErr.takeError();

    ProducerIdentification = *ProducerIdentificationOrErr;
  }

  Stream.JumpToBit(ModuleBit);
  auto *R = new BitcodeReader(std::move(Stream), Strtab, ProducerIdentification,
                              Context);

  std::unique_ptr<Module> M =
      llvm::make_unique<Module>(ModuleIdentifier, Context);
  M->setMaterializer(R);

  // Delay parsing Metadata if ShouldLazyLoadMetadata is true.
  if (Error Err =
          R->parseBitcodeInto(M.get(), ShouldLazyLoadMetadata, IsImporting))
    return std::move(Err);

  if (MaterializeAll) {
    // Read in the entire module, and destroy the BitcodeReader.
    if (Error Err = M->materializeAll())
      return std::move(Err);
  } else {
    // Resolve forward references from blockaddresses.
    if (Error Err = R->materializeForwardReferencedFunctions())
      return std::move(Err);
  }
  return std::move(M);
}

Expected<std::unique_ptr<Module>>
BitcodeModule::getLazyModule(LLVMContext &Context, bool ShouldLazyLoadMetadata,