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+# CodeQL CLI changelog
+
+## Release 2.2.3 (2020-06-15)
+
+CodeQL CLI 2.2.3 is the same as version 2.2.2, but re-released with a new
+version number because the `v2.2.2` folder on the download site
+originally contained the 2.2.0 binaries instead of the correct 2.2.2
+ones.
+
+If you have downloaded release 2.2.2, and `codeql --version` correctly
+identifies itself as being that version, you don't need to upgrade to
+2.2.3.
+
+## Release 2.2.2 (2020-06-12)
+
+-   The bundled extractors are updated to match the versions currently
+    used on LGTM.com. These are newer than the last release (1.24) of
+    LGTM Enterprise. If you plan to upload databases to an LGTM
+    Enterprise 1.24 instance, you need to create them with release
+    2.1.4.
+
+### Improvements
+
+-   Query evaluations that time out due to a `--timeout` option are no
+    longer silently discarded. Instead `codeql` will terminate with exit
+    code 33. Commands that evaluate multiple queries will produce as
+    much output as they can even if one of the queries times out.
+
+## Release 2.2.1
+
+There is no CodeQL CLI version 2.2.1. This version number was used
+internally to work around restrictions in the CodeQL for VS Code
+extension.
+
+## Release 2.2.0 (2020-05-29)
+
+-   The bundled extractors are updated to match the versions currently
+    used on LGTM.com. These are newer than the last release (1.24) of
+    LGTM Enterprise. If you plan to upload databases to an LGTM
+    Enterprise 1.24 instance, you need to create them with release
+    2.1.4.
+-   Starting with this release, the CodeQL CLI can be downloaded either
+    as a single `codeql.zip` file containing the CLI for all supported
+    platforms, or as a `codeql-PLATFORM.zip` that contains the files for
+    just one platform. The single-platform zips are faster to download.
+
+### QL language improvement
+
+-   QL now supports the definition of new types as type unions. This
+    feature currently allows unions of branches from an already existing
+    algebraic data type and unions of database types.
+
+## Release 2.1.4 (2020-05-26)
+
+This release corresponds to release 1.24.x of LGTM Enterprise, and
+should be used when creating databases that will be uploaded to it.
+Future CLI releases (numbered 2.2.x) may produce databases that are not
+backwards compatible with this version of LGTM Enterprise.
+
+For all purposes other than creating databases for LGTM Enterprise we
+recommend that you continue upgrading to newer CLI releases as they
+become available.
+
+### Features added
+
+-   A new `codeql query format` command exposes the QL autoformatter for
+    use on the command line.
+
+### Bugs fixed
+
+-   `-J` command-line options that contain spaces now ought to work on
+    Windows. They still do not work reliably on Linux or MacOS, though.
+
+## Release 2.1.3 (2020-05-13)
+
+### Bugs fixed 
+
+-   Fixes a bug in `codeql execute cli-server` (a helper used by the VS
+    Code extension) which would sometimes cause query compilation to
+    fail until the extension was restarted.
+-   Fixes a bug in `codeql database upgrade` which could lead to
+    performance losses if the upgraded database was subsequently used
+    with LGTM or the legacy Semmle Core product.
+-   Fixes a bug in the QL evaluator that would sometimes lead to crashes
+    for queries that use the new `unique` aggregate added in release
+    2.1.0.
+-   The value of the `--compilation-cache-size` option is now correctly
+    interpreted as a number of megabytes rather than a number of bytes.
+
+## Release 2.1.2 (2020-05-06)
+
+-   Updated license terms to allow CI use with GitHub Actions for
+    open-source software.
+
+### Potentially breaking changes
+
+-   In [query suite definitions](https://help.semmle.com/codeql/codeql-cli/procedures/query-suites.html), filter
+    instructions that filter on the `query path` pseudo-tag will now
+    always see the relative path to the query expressed with `/` as a
+    directory separator, independently of the platform. Previously they
+    erroneously used the platform's directory separator, meaning that
+    query suites developed on Windows would not work correctly on Unix
+    systems (and vice versa) if they used `query path`. Existing suite
+    definitions developed on Windows may need to be updated to match the
+    new behavior.
+
+### Features added
+
+-   A new `codeql test accept` subcommand helps automate updating the
+    expected output for unit tests after a desired change in query
+    behavior. This can also be done by the new `--learn` option for
+    `codeql test run`.
+
+### Bugs fixed
+
+-   `codeql database create` will now report an explicit error if given
+    a `--command` argument that specifies an empty string. Previously
+    this would be accepted initially, leading to confusing failures
+    later.
+
+## Release 2.1.1 (2020-04-20)
+
+-   The bundled extractors are updated to match the versions currently
+    used on LGTM.com.
+
+### Features added
+
+-   `codeql resolve queries` accepts a `--format=bylanguage` option.
+    This is used to help automated workflows determine which languages
+    to create databases for, from the queries that are available to run.
+-   It is now possible to attempt to execute `.ql` files that are not in
+    a QL pack. This is used by a few specialized internal workflows.
+    However, standalone queries cannot import any of the dependencies
+    that you would usually declare in a `qlpack.yml` file, so will not
+    be useful in most cases.
+
+## Release 2.1.0 (2020-03-27)
+
+-   The bundled extractors are updated to match the versions currently
+    used on LGTM.com. These are newer than the last release (1.23) of
+    LGTM Enterprise. If you plan to upload databases to an LGTM
+    Enterprise 1.23 instance, you need to create them with release
+    2.0.1. For more information, see [Preparing CodeQL databases to
+    upload to
+    LGTM](https://help.semmle.com/lgtm-enterprise/admin/help/prepare-database-upload.html)
+    in the LGTM admin help.
+
+### Potentially breaking changes
+
+-   If you pass a directory name as a command-line argument to
+    `codeql test run`, it will now consider all `.ql` or `.qlref` files
+    found under that directory to be test queries, even if they have no
+    accompanying `.expected` file. Tests that lack an `.expected` file
+    will fail, but will generate an `.actual` file that you can rename
+    to `.expected` if you want to use the results.
+
+    The goal of this change is to support existing workflows of
+    experienced CodeQL users, and also to provide clear error
+    indications if an `.expected` file is accidentally lost, renamed, or
+    misspelled.
+
+    However, if you invoke `codeql test run` on a directory tree that
+    contains both tests and non-test queries, you will now encounter
+    errors if any of the `.ql` files can't be processed as test queries.
+    If you're affected by this change, you can suppress these errors by:
+
+    -   Adding a `tests` property to this QL pack to define specify
+        which directories contain only test queries and associated test
+        code. For more information, see
+        [About QL packs](https://help.semmle.com/codeql/codeql-cli/reference/qlpack-overview.html).
+    -   Running `codeql test run` with a new `--strict-test-discovery`
+        option.
+
+    In the longer term, we recommend that you reorganize the queries so
+    that test queries are stored in a directory tree that's separate
+    from actual queries.
+
+-   `codeql database create` and `codeql database finalize` will no
+    longer recognize a `--no-duplicate-code` option. This option has
+    never had any effect, and its positive variant `--duplicate-code`
+    previously led to a fatal error.
+
+### Features added
+
+-   A new XML extractor is included. It is not intended to be used as a
+    stand-alone extractor, but rather to augment the data produced by
+    other extractors. In particular, the C\# and Java extractors invoke
+    it during database creation to include information relevant to the
+    analysis of those languages, much like LGTM.com does.
+-   Two new plumbing commands `codeql database index-files` and
+    `codeql resolve files` have been added for support of invoking the
+    XML extractor support. These commands are generally only of interest
+    for extractor authors.
+-   Two new plumbing commands have been added to `codeql dataset`. The
+    `measure` subcommand can be used to collect size information from a
+    dataset, and the `check` subcommand can scan a dataset for database
+    inconsistencies. These commands are useful when developing a new
+    CodeQL extractor.
+-   The QL evaluator contains a number of features in support of an
+    internal experiment with using machine-learning techniques to
+    identify functions in unknown codebases as sources or sinks of
+    taint. This includes new command-line options `--ml-model-path` and
+    `--native-library-path` to several subcommands. As the new features
+    are not yet ready for general use, these new options should be
+    ignored by external CodeQL users.
+
+### Bugs fixed
+
+-   Fixes a bug that could result in empty databases for C/C++.
+    Previously, extraction would mistakenly be skipped for source files
+    compiled with the Clang compiler, if the `-fintegrated-cc1` option
+    was specified.
+-   `codeql database create` and `codeql database init` will now, as
+    they have always been documented, refuse to create a database whose
+    parent directory doesn't already exist.
+-   `codeql test run` will no longer leave `.actual` files from previous
+    runs in the file system after a test passes.
+
+### QL language improvements
+
+-   QL now supports set literals, and the QL extractor can identify them
+    with the `SetLiteral` class. For more information, see [Set literal
+    expressions](https://help.semmle.com/QL/ql-handbook/expressions.html#set-literal-expressions)
+    in the QL language reference.
+-   QL now supports a uniqueness aggregate. This can express constraints
+    that there is precisely one value. The syntax is taken from previous
+    aggregates such as `min` and `max`.
+
+    ``` {.sourceCode .ql}
+    unique(int x | x = 4 or x = 2 * 2 | x)
+    ```
+
+## Release 2.0.6 (2020-03-16)
+
+### Bugs fixed
+
+-   Fixes a problem preventing `codeql database create` from working
+    with Python 3 on macOS.
+-   Fixes a problem preventing `codeql database create` from finding
+    locally installed Python packages.
+
+## Release 2.0.5 (2020-03-13)
+
+-   The bundled extractors (which are responsible for converting source
+    code to databases for each supported language) are updated to match
+    the versions currently used on LGTM.com. These are newer than the
+    last release of LGTM Enterprise, so this release should not be used
+    if you plan to upload databases to an LGTM Enterprise instance. For
+    more information, see [Preparing CodeQL databases to upload to
+    LGTM](https://help.semmle.com/lgtm-enterprise/admin/help/prepare-database-upload.html)
+    in the LGTM admin help.
+
+### Features added
+
+-   `codeql test run` has a new `--slice` option that can be used to
+    parallelize tests over more machines.
+
+## Release 2.0.4 (2020-02-21)
+
+-   The bundled extractors (which are responsible for converting source
+    code to databases for each supported language) are updated to match
+    the versions currently used on LGTM.com. These are newer than the
+    last release of LGTM Enterprise, so this release should not be used
+    if you plan to upload databases to an LGTM Enterprise instance. For
+    more information, see [Preparing CodeQL databases to upload to
+    LGTM](https://help.semmle.com/lgtm-enterprise/admin/help/prepare-database-upload.html)
+    in the LGTM admin help.
+
+### Features added
+
+-   Subcommands that execute queries (such as `codeql database analyze`)
+    now have a `--timeout` option that can be used to set a timeout to
+    automatically cancel query evaluations that appear to diverge.
+-   A new plumbing command `codeql query decompile` can display the DIL
+    intermediate representations that is included in the output of
+    `codeql query compile --dump-qlo --include-dil-in-qlo`. This is
+    useful mainly for certain internal workflows; the information
+    produced is the same as what `codeql query compile --dump-dil`
+    already outputs.
+
+### Bugs fixed
+
+-   The `--debug` and `--tuple-counting` options to
+    `codeql test run` erroneously had no effect. Now they ought to work.
+
+## Release 2.0.3 (2020-02-12)
+
+### Bugs fixed
+
+-   Fixes a bug where `codeql test run` would fail with the
+    message
+    `CatastrophicError: There should be a --library-path option for com.semmle.cli2.LibraryPathOptions.libraryPath but we didn't find it`
+    when running tests against the `master` branch of the CodeQL
+    libraries for certain languages.
+-   Otherwise identical to release 2.0.2.
+
+## Release 2.0.2 (2020-02-05)
+
+-   The bundled extractors (which are responsible for converting source
+    code to databases for each supported language) are updated to match
+    the versions currently used on LGTM.com. These are newer than the
+    last release of LGTM Enterprise, so this release should not be used
+    if you plan to upload databases to an LGTM Enterprise instance. For
+    more information, see [Preparing CodeQL databases to upload to
+    LGTM](https://help.semmle.com/lgtm-enterprise/admin/help/prepare-database-upload.html)
+    in the LGTM admin help.
+-   The parent and sibling directories of the unpacked CLI are no longer
+    searched recursively for QL packs. QL packs will only be found if
+    there's a `qlpack.yml` or `.codeqlmanifest.json` directly in a
+    parent or sibling directory. This should eliminate the very long
+    disk-scanning delays experienced by users who unpacked earlier
+    versions of the CLI in their home directory.
+-   Parent and sibling directories of the unpacked CLI will now be
+    searched for QL packs as a last resort, even if you give an explicit
+    `--search-path` option. This means, for example, that you can define
+    a search path in the [per-user configuration file](https://help.semmle.com/codeql/codeql-cli/reference/configuration-overview.html) without it depending on
+    where the CLI is unpacked. In particular, the setting can now be
+    meaningfully used by users who let the CodeQL for VS Code extension
+    manage the downloading and unpacking of the CLI.
+
+### Security updates
+
+-   The `codeql database create` command and its relatives will no
+    longer attempt to find extractors located in the parent and sibling
+    directories of the unpacked CLI. This closes a security risk for
+    users who unpacked the CodeQL CLI in their home directory. This
+    could've resulted in arbitrary code execution if the user unpacked a
+    file archive containing a malicious extractor anywhere in the home
+    directory. Extractors will now only be found within the unpacked CLI
+    itself, or in directories explicitly listed in the `--search-path`.
+    It is expected that users will only point `--search-path` to
+    locations they trust at least as much as the CLI download itself.
+
+### Features added
+
+-   This release supports executing query regression tests using the
+    `codeql test` command. For further information, see
+    [Testing custom queries](https://help.semmle.com/codeql/codeql-cli/procedures/test-queries.html).
+-   The error message if you try executing a query against a database
+    that needs to be upgraded (which can happen routinely if you're
+    using a fresh `master` checkout of the CodeQL libraries with the
+    bundled extractors) will now explicitly suggest a
+    `codeql database update` command to run. The database is not
+    automatically upgraded, as this may make it irreversibly
+    incompatible with older versions of the CodeQL libraries. This
+    allows users who want to compare behavior of different versions of
+    the libraries against the same database to make a copy before they
+    upgrade it.
+
+## Release 2.0.1 (2019-12-17)
+
+-   Corresponds to LGTM Enterprise release 1.23.
+-   The bundled extractors (which are responsible for converting source
+    code to databases for each supported language) are updated to match
+    the extractor versions used in LGTM Enterprise.
+-   No other changes to the core CLI.
+
+## Release 2.0.0 (2019-11-14)
+
+-   First public release.
+