CodePlan: Repository-level Coding using LLMs and Planning
Authors: name: Ramakrishna Bairi, name: Atharv Sonwane, name: Aditya Kanade, name: Vageesh D C, name: Arun Iyer, name: Suresh Parthasarathy, name: Sriram Rajamani, name: B. Ashok, name: Shashank Shet

Software engineering activities such as package migration, fixing errors
reports from static analysis or testing, and adding type annotations or other
specifications to a codebase, involve pervasively editing the entire repository
of code. We formulate these activities as repository-level coding tasks.
  Recent tools like GitHub Copilot, which are powered by Large Language Models
(LLMs), have succeeded in offering high-quality solutions to localized coding
problems. Repository-level coding tasks are more involved and cannot be solved
directly using LLMs, since code within a repository is inter-dependent and the
entire repository may be too large to fit into the prompt. We frame
repository-level coding as a planning problem and present a task-agnostic
framework, called CodePlan to solve it. CodePlan synthesizes a multi-step chain
of edits (plan), where each step results in a call to an LLM on a code location
with context derived from the entire repository, previous code changes and
task-specific instructions. CodePlan is based on a novel combination of an
incremental dependency analysis, a change may-impact analysis and an adaptive
planning algorithm.
  We evaluate the effectiveness of CodePlan on two repository-level tasks:
package migration (C#) and temporal code edits (Python). Each task is evaluated
on multiple code repositories, each of which requires inter-dependent changes
to many files (between 2-97 files). Coding tasks of this level of complexity
have not been automated using LLMs before. Our results show that CodePlan has
better match with the ground truth compared to baselines. CodePlan is able to
get 5/6 repositories to pass the validity checks (e.g., to build without errors
and make correct code edits) whereas the baselines (without planning but with
the same type of contextual information as CodePlan) cannot get any of the
repositories to pass them.