15936a5f8d
Previously, apply_rules_inner snapshotted a node's fields by cloning the BTreeMap into a Vec<(FieldId, Vec<Id>)>, then built a fresh BTreeMap of new_fields for the rewritten Ids. For a node with N fields, this allocated 2N+1 things per visit (the snapshot Vec, N cloned children Vecs, the new BTreeMap entries) — even when nothing in the subtree was rewritten. Use std::mem::take to swap the parent's fields out by ownership: the recursion can mutate the AST (including pushing new nodes from rule firings) without any conflict, since we hold the owned BTreeMap locally. Iterate values_mut() and only allocate a fresh children Vec on the first divergence (lazy alloc): unchanged children stay in the existing slot. When done, swap the fields back. For a subtree with no rewrites, this is now zero allocations per node (modulo the recursion itself). For nodes with rewrites, it's one Vec allocation per field that contains a rewritten child, instead of two plus the BTreeMap rebuild.
CodeQL
This open source repository contains the standard CodeQL libraries and queries that power GitHub Advanced Security and the other application security products that GitHub makes available to its customers worldwide.
How do I learn CodeQL and run queries?
There is extensive documentation about the CodeQL language, writing CodeQL using the CodeQL extension for Visual Studio Code and using the CodeQL CLI.
Contributing
We welcome contributions to our standard library and standard checks. Do you have an idea for a new check, or how to improve an existing query? Then please go ahead and open a pull request! Before you do, though, please take the time to read our contributing guidelines. You can also consult our style guides to learn how to format your code for consistency and clarity, how to write query metadata, and how to write query help documentation for your query.
For information on contributing to CodeQL documentation, see the "contributing guide" for docs.
License
The code in this repository is licensed under the MIT License by GitHub.
The CodeQL CLI (including the CodeQL engine) is hosted in a different repository and is licensed separately. If you'd like to use the CodeQL CLI to analyze closed-source code, you will need a separate commercial license; please contact us for further help.
Visual Studio Code integration
If you use Visual Studio Code to work in this repository, there are a few integration features to make development easier.
CodeQL for Visual Studio Code
You can install the CodeQL for Visual Studio Code extension to get syntax highlighting, IntelliSense, and code navigation for the QL language, as well as unit test support for testing CodeQL libraries and queries.
Tasks
The .vscode/tasks.json file defines custom tasks specific to working in this repository. To invoke one of these tasks, select the Terminal | Run Task... menu option, and then select the desired task from the dropdown. You can also invoke the Tasks: Run Task command from the command palette.