<< Remembering and restoring declarations >>

• Each front-end is responsible for:
  • remembering top-level declarations;
  • remembering / checking dependencies;
  • restoring declarations if re-use is ok.
• Hooks/conventions to make this relatively easy.
• Complication: Old tree nodes get modified with new information. E.g. C++ function overloading.
• Likely solution: Remember modifications in undo buffers. Before re-starting compilation, we must undo modifications to old trees.