---
title: generate overlay-changes
intro: |
  [Plumbing] Generate a file that can be used for the
versions: # DO NOT MANUALLY EDIT. CHANGES WILL BE OVERWRITTEN BY A 🤖
  fpt: '*'
  ghec: '*'
  ghes: '*'
topics:
  - Code Security
  - Code scanning
  - CodeQL
type: reference
product: '{% data reusables.gated-features.codeql %}'
autogenerated: codeql-cli
---

<!-- Content after this section is automatically generated -->

{% data reusables.codeql-cli.man-pages-version-note %}

## Synopsis

```shell copy
codeql generate overlay-changes [--source-root=<dir>] [--output=<file>] <options>... -- <database>
```

## Description

\[Plumbing] Generate a file that can be used for the
`--overlay-changes` option to
[codeql database create](/code-security/codeql-cli/codeql-cli-manual/database-create) when extracting an overlay database.

This command is intended to be used mostly for manual or automated
testing. It is not particularly efficient. For production use, consider
if the changes file can instead be derived from something like
`git diff --name-only`.

## Options

### Primary Options

#### `<database>`

\[Mandatory] Path to the _base_ database into which the overlay will be
extracted.

#### `-s, --source-root=<dir>`

The directory containing the source code to be extracted as an overlay.
If not given, the current working directory is used.

#### `-o, --output=<file>`

The changes file will be written to this location. If it is not
specified, the changes will be written to standard output.

### Common options

#### `-h, --help`

Show this help text.

#### `-J=<opt>`

\[Advanced] Give option to the JVM running the command.

(Beware that options containing spaces will not be handled correctly.)

#### `-v, --verbose`

Incrementally increase the number of progress messages printed.

#### `-q, --quiet`

Incrementally decrease the number of progress messages printed.

#### `--verbosity=<level>`

\[Advanced] Explicitly set the verbosity level to one of errors,
warnings, progress, progress+, progress++, progress+++. Overrides `-v`
and `-q`.

#### `--logdir=<dir>`

\[Advanced] Write detailed logs to one or more files in the given
directory, with generated names that include timestamps and the name of
the running subcommand.

(To write a log file with a name you have full control over, instead
give `--log-to-stderr` and redirect stderr as desired.)

#### `--common-caches=<dir>`

\[Advanced] Controls the location of cached data on disk that will
persist between several runs of the CLI, such as downloaded QL packs and
compiled query plans. If not set explicitly, this defaults to a
directory named `.codeql` in the user's home directory; it will be
created if it doesn't already exist.

Available since `v2.15.2`.