Target pattern syntax

The BUILD file label syntax is used to specify a single target. Target patterns generalize this syntax to sets of targets, and also support working-directory-relative forms, recursion, subtraction and filtering.

Examples

Specifying a single target:

//foo/bar:wiz The single target '//foo/bar:wiz'.

foo/bar/wiz Equivalent to:

• //foo/bar/wiz:wiz if foo/bar/wiz is a package (there is a BUILD file in the wiz folder),
• //foo/bar:wiz if foo/bar is a package,
• //foo:bar/wiz otherwise.

//foo/bar Equivalent to '//foo/bar:bar'.

Specifying all rules in a package:

//foo/bar:all Matches all rules in package 'foo/bar'.

Specifying all rules recursively beneath a package:

//foo/...:all Matches all rules in all packages beneath directory 'foo'. //foo/... (ditto)

By default, directory symlinks are followed when performing this recursive traversal, except those that point to under the output base (for example, the convenience symlinks that are created in the root directory of the workspace) But we understand that your workspace may intentionally contain directories with weird symlink structures that you don't want consumed. As such, if a directory has a file named 'DONT_FOLLOW_SYMLINKS_WHEN_TRAVERSING_THIS_DIRECTORY_VIA_A_RECURSIVE_TARGET_PATTERN' then symlinks in that directory won't be followed when evaluating recursive target patterns.

Working-directory relative forms

(assume cwd = 'workspace/foo')

Target patterns which do not begin with '//' are taken relative to the working directory. Patterns which begin with '//' are always absolute.

...:all Equivalent to '//foo/...:all'. ... (ditto)

bar/...:all Equivalent to '//foo/bar/...:all'. bar/... (ditto)

bar:wiz Equivalent to '//foo/bar:wiz'. :foo Equivalent to '//foo:foo'.

bar Equivalent to '//foo/bar:bar'. foo/bar Equivalent to '//foo/foo/bar:bar'.

bar:all Equivalent to '//foo/bar:all'. :all Equivalent to '//foo:all'.

Summary of target wildcards

• :all Match all rules in the specified packages.
• :* or :all-targets Match all targets (rules and files) in the specified packages including .par and _deploy.jar files.

Subtractive patterns

Target patterns may be preceded by '-', meaning they should be subtracted from the set of targets accumulated by preceding patterns. (Note that this means order matters.) For example:

% bazel build -- foo/... -foo/contrib/...

builds everything in foo, except contrib. In case a target not under contrib depends on something under contrib though, in order to build the former bazel has to build the latter too. As usual, the -- is required to prevent -f from being interpreted as an option.

When running the test command, test suite expansion is applied to each target pattern in sequence as the set of targets is evaluated. This means that individual tests from a test suite can be excluded by a later target pattern. It also means that an exclusion target pattern which matches a test suite will exclude all tests which that test suite references. (Targets that would be matched by the list of target patterns without any test suite expansion are also built unless --build_tests_only is set.)