Instructions for declaring, formatting, emitting, testing, and styling diagnostic messages (errors, warnings, and the labels that explain them) in the Carbon toolchain.
Instructions for working on Carbon's LSP language server, including its architecture, its file_test-based tests, and the VS Code extension.
Instructions for checking, building, debugging, and understanding the Carbon toolchain.
Instructions for authoring, structuring, and running toolchain tests using the file_test infrastructure.
Instructions for judging whether changes to file test output (`// CHECK:STDOUT:` and `// CHECK:STDERR:` lines) are correct, which changes are acceptable churn, and which are regressions in disguise.
Instructions for summarizing changes to Carbon testdata files (`toolchain/*/testdata`).
Instructions for code formatting and style guidelines in the Carbon toolchain.
Instructions for using Jujutsu (jj) for version control in the Carbon repository.