|  | --- | 
|  | layout: documentation | 
|  | title: Query Language | 
|  | --- | 
|  | <h1>The Bazel Query Reference</h1> | 
|  |  | 
|  | <p> | 
|  | When you use <code>bazel query</code> to analyze build | 
|  | dependencies, you use a little language, the <em>Bazel Query | 
|  | Language</em>.  This document is the reference manual for that | 
|  | language.  This document also describes the output | 
|  | formats <code>bazel query</code> supports. | 
|  | </p> | 
|  |  | 
|  | <h2>Examples</h2> | 
|  |  | 
|  | <p> | 
|  | How do people use <code>bazel query</code>?  Here are typical examples: | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | Why does the <code>//foo</code> tree depend on <code>//bar/baz</code>? | 
|  | Show a path:</p> | 
|  | <pre>somepath(foo/..., //bar/baz:all)</pre> | 
|  |  | 
|  |  | 
|  | <p> | 
|  | What C++ libraries do all the <code>foo</code> tests depend on that | 
|  | the <code>foo_bin</code> target does not?</p> | 
|  | <pre>kind("cc_library", deps(kind(".*test rule", foo/...)) except deps(//foo:foo_bin))</pre> | 
|  |  | 
|  |  | 
|  | <h2>Tokens: the lexical syntax</h2> | 
|  |  | 
|  | <p> | 
|  | Expressions in the query language are composed of the following | 
|  | tokens:</p> | 
|  | <ul> | 
|  | <li> | 
|  | <p> | 
|  | <b>Keywords</b>, such as <code>somepath</code> or | 
|  | <code>let</code>.  Keywords are the reserved words of the | 
|  | language, and each of them is described below.  The complete set | 
|  | of keywords is: | 
|  | </p> | 
|  |  | 
|  | <code><!-- keep this alphabetically sorted --> | 
|  | <a href="#path-operators">allpaths</a><br/> | 
|  | <a href="#attr">attr</a><br/> | 
|  |  | 
|  | <a href="#buildfiles">buildfiles</a><br/> | 
|  |  | 
|  | <a href="#deps">deps</a><br/> | 
|  | <a href="#set-operations">except</a><br/> | 
|  | <a href="#filter">filter</a><br/> | 
|  | <a href="#variables">in</a><br/> | 
|  | <a href="#set-operations">intersect</a><br/> | 
|  | <a href="#kind">kind</a><br/> | 
|  | <a href="#labels">labels</a><br/> | 
|  | <a href="#variables">let</a><br/> | 
|  | <a href="#loadfiles">loadfiles</a><br/> | 
|  | <a href="#rdeps">rdeps</a><br/> | 
|  | <a href="#set">set</a><br/> | 
|  | <a href="#some">some</a><br/> | 
|  | <a href="#path-operators">somepath</a><br/> | 
|  | <a href="#tests">tests</a><br/> | 
|  | <a href="#set-operations">union</a><br/> | 
|  | </code> | 
|  | </li> | 
|  |  | 
|  | <li> | 
|  | <p> | 
|  | <b>Words</b>, such as <code>foo/...</code> or | 
|  | <code>".*test rule"</code> or | 
|  | <code>//bar/baz:all</code>. | 
|  | If a character sequence is "quoted" (begins and ends with a | 
|  | single-quote <code>'</code>, or begins and ends with a | 
|  | double-quote <code>"</code>), it is a word. | 
|  | If a character sequence is not quoted, it may still be parsed as a word. | 
|  | Unquoted words are sequences of characters drawn from | 
|  | the set of alphabet characters, numerals, slash <code>/</code>, | 
|  | hyphen <code>-</code>, underscore <code>_</code>, star <code>*</code>, and | 
|  | period <code>.</code>. Unquoted words may not start with a | 
|  | hyphen or period. | 
|  | </p> | 
|  |  | 
|  | <p>We chose this syntax so that quote marks aren't needed in most cases. | 
|  | The (unusual) <code>".*test rule"</code> example needs quotes: it | 
|  | starts with a period and contains a space. | 
|  | Quoting <code>"cc_library"</code> is unnecessary but harmless. | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | Quoting <em>is</em> necessary when writing scripts that | 
|  | construct Bazel query expressions from user-supplied values. | 
|  |  | 
|  | </p> | 
|  | <pre> | 
|  | //foo:bar+wiz    # WRONG: scanned as //foo:bar + wiz. | 
|  | //foo:bar=wiz    # WRONG: scanned as //foo:bar = wiz. | 
|  | "//foo:bar+wiz"  # ok. | 
|  | "//foo:bar=wiz"  # ok. | 
|  | </pre> | 
|  | <p> | 
|  | Note that this quoting is in addition to any quoting that may | 
|  | be required by your shell. e.g. | 
|  | </p> | 
|  | <pre>% bazel query ' "//foo:bar=wiz" '     # single-quotes for shell, double-quotes for Bazel.</pre> | 
|  |  | 
|  | <p> | 
|  | Keywords, when quoted, are treated as ordinary words, thus | 
|  | <code>some</code> is a keyword but <code>"some"</code> is a word. | 
|  | Both <code>foo</code> and <code>"foo"</code> are words. | 
|  | </p> | 
|  |  | 
|  | <li><b>Punctuation</b>, such as parens <code>()</code>, period | 
|  | <code>.</code> and comma <code>,</code>, etc.  Words containing | 
|  | punctuation (other than the exceptions listed above) must be quoted. | 
|  | </ul> | 
|  |  | 
|  | <p> | 
|  | Whitespace characters outside of a quoted word are ignored. | 
|  | </p> | 
|  |  | 
|  | <h2 id='concepts'>Bazel Query Language Concepts</h2> | 
|  | <p> | 
|  | The Bazel query language is a language of expressions.  Every | 
|  | expression evaluates to a <b>partially-ordered set</b> of targets, | 
|  | or equivalently, a <b>graph</b> (DAG) of targets.  This is the only | 
|  | datatype. | 
|  | </p> | 
|  | <p> | 
|  | In some expressions, the partial order of the graph is | 
|  | not interesting; In this case, we call the values | 
|  | "sets". In cases where the partial order of elements | 
|  | is significant, we call values "graphs".  Note | 
|  | that both terms refer to the same datatype, but merely emphasize | 
|  | different aspects of it. | 
|  | </p> | 
|  |  | 
|  | <h3>Cycles in the dependency graph</h3> | 
|  | <p> | 
|  | Build dependency graphs should be acyclic. | 
|  |  | 
|  | The algorithms used by the query language are intended for use in | 
|  | acyclic graphs, but are robust against cycles.  The details of how | 
|  | cycles are treated are not specified and should not be relied upon. | 
|  | </p> | 
|  |  | 
|  | <h3 id='implicit_deps'>Implicit dependencies</h3> | 
|  |  | 
|  | <p> | 
|  | In addition to build dependencies that are defined explicitly in BUILD files, | 
|  | Bazel adds additional <em>implicit</em> dependencies to rules. For example | 
|  | every Java rule implicitly depends on the JavaBuilder. Implicit dependencies | 
|  | are established using attributes that start with <code>$</code> and they | 
|  | cannot be overridden in BUILD files. | 
|  |  | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | Per default <code>bazel query</code> takes implicit dependencies into account | 
|  | when computing the query result. This behavior can be changed with | 
|  | the <code>--[no]implicit_deps</code> option. | 
|  | </p> | 
|  |  | 
|  | <h3 id='soundness'>Soundness</h3> | 
|  |  | 
|  | <p> | 
|  | Bazel query language expressions operate over the build | 
|  | dependency graph, which is the graph implicitly defined by all | 
|  | rule declarations in all BUILD files.  It is important to understand | 
|  | that this graph is somewhat abstract, and does not constitute a | 
|  | complete description of how to perform all the steps of a build.  In | 
|  | order to perform a build, a <em>configuration</em> is required too; | 
|  | see the <a href='bazel-user-manual.html#configurations'>configurations</a> | 
|  | section of the User's Guide for more detail. | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | The result of evaluating an expression in the Bazel query language | 
|  | is true <em>for all configurations</em>, which means that it may be | 
|  | a conservative over-approximation, and not exactly precise.  If you | 
|  | use the query tool to compute the set of all source files needed | 
|  | during a build, it may report more than are actually necessary | 
|  | because, for example, the query tool will include all the files | 
|  | needed to support message translation, even though you don't intend | 
|  | to use that feature in your build. | 
|  | </p> | 
|  |  | 
|  | <h3 id='graph-order'>On the preservation of graph order</h3> | 
|  |  | 
|  | <p> | 
|  | Operations preserve any ordering | 
|  | constraints inherited from their subexpressions.  You can think of | 
|  | this as "the law of conservation of partial order".  Consider an | 
|  | example: if you issue a query to determine the transitive closure of | 
|  | dependencies of a particular target, the resulting set is ordered | 
|  | according to the dependency graph.  If you filter that set to | 
|  | include only the targets of <code>file</code> kind, the same | 
|  | <em>transitive</em> partial ordering relation holds between every | 
|  | pair of targets in the resulting subset—even though none of | 
|  | these pairs is actually directly connected in the original graph. | 
|  | (There are no file–file edges in the build dependency graph). | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | However, while all operators <em>preserve</em> order, some | 
|  | operations, such as the <a href='#set-operations'>set operations</a> | 
|  | don't <em>introduce</em> any ordering constraints of their own. | 
|  | Consider this expression: | 
|  | </p> | 
|  |  | 
|  | <pre>deps(x) union y</pre> | 
|  |  | 
|  | <p> | 
|  | The order of the final result set is guaranteed to preserve all the | 
|  | ordering constraints of its subexpressions, namely, that all the | 
|  | transitive dependencies of <code>x</code> are correctly ordered with | 
|  | respect to each other.  However, the query guarantees nothing about | 
|  | the ordering of the targets in <code>y</code>, nor about the | 
|  | ordering of the targets in <code>deps(x)</code> relative to those in | 
|  | <code>y</code> (except for those targets in | 
|  | <code>y</code> that also happen to be in <code>deps(x)</code>). | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | Operators that introduce ordering constraints include: | 
|  | <code>allpaths</code>, | 
|  | <code>deps</code>, | 
|  | <code>rdeps</code>, | 
|  | <code>somepath</code>, | 
|  | and the target pattern wildcards | 
|  | <code>package:*</code>, | 
|  | <code>dir/...</code>, etc. | 
|  | </p> | 
|  |  | 
|  | <h2>Expressions: syntax and semantics of the grammar</h2> | 
|  |  | 
|  | <p> | 
|  | This is the grammar of the Bazel query language, expressed in EBNF | 
|  | notation: | 
|  | </p> | 
|  |  | 
|  |  | 
|  | <pre>expr ::= <var>word</var> | 
|  | | let <var>name</var> = <var>expr</var> in <var>expr</var> | 
|  | | (<var>expr</var>) | 
|  | | <var>expr</var> intersect <var>expr</var> | 
|  | | <var>expr</var> ^ <var>expr</var> | 
|  | | <var>expr</var> union <var>expr</var> | 
|  | | <var>expr</var> + <var>expr</var> | 
|  | | <var>expr</var> except <var>expr</var> | 
|  | | <var>expr</var> - <var>expr</var> | 
|  | | deps(<var>expr</var>) | 
|  | | deps(<var>expr</var>, <var>depth</var>) | 
|  | | rdeps(<var>expr</var>, <var>expr</var>) | 
|  | | rdeps(<var>expr</var>, <var>expr</var>, <var>depth</var>) | 
|  | | some(<var>expr</var>) | 
|  | | somepath(<var>expr</var>, <var>expr</var>) | 
|  | | allpaths(<var>expr</var>, <var>expr</var>) | 
|  | | kind(<var>word</var>, <var>expr</var>) | 
|  | | labels(<var>word</var>, <var>expr</var>) | 
|  | | filter(<var>word</var>, <var>expr</var>) | 
|  | | set(<var>word</var> *) | 
|  | | attr(<var>word</var>, <var>word</var>, <var>expr</var>) | 
|  | </pre> | 
|  |  | 
|  | <p> | 
|  | We will examine each of the productions of this grammar in order. | 
|  | </p> | 
|  |  | 
|  | <h3 id="target-patterns">Target patterns</h3> | 
|  | <pre>expr ::= <var>word</var></pre> | 
|  | <p> | 
|  | Syntactically, a <em>target pattern</em> is just a word. It | 
|  | is interpreted as an (unordered) set of targets.  The simplest | 
|  | target pattern is a label, | 
|  | which identifies a single target (file or rule).  For example, the | 
|  | target pattern <code>//foo:bar</code> evaluates to a set | 
|  | containing one element, the target, the <code>bar</code> | 
|  | rule. | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | Target patterns generalize labels to include wildcards over packages | 
|  | and targets.  For example, <code>foo/...:all</code> (or | 
|  | just <code>foo/...</code>) is a target pattern that evaluates to a | 
|  | set containing all <em>rules</em> in every package recursively | 
|  | beneath the <code>foo</code> directory; | 
|  | <code>bar/baz:all</code> is a target pattern that | 
|  | evaluates to a set containing all the rules in the | 
|  | <code>bar/baz</code> package, but not its subpackages. | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | Similarly, <code>foo/...:*</code> is a target pattern that evaluates | 
|  | to a set containing all <em>targets</em> (rules <em>and</em> files) in | 
|  | every package recursively beneath the <code>foo</code> directory; | 
|  | <code>bar/baz:*</code> evaluates to a set containing | 
|  | all the targets in the | 
|  | <code>bar/baz</code> package, but not its subpackages. | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | Because the <code>:*</code> wildcard matches files as well as rules, | 
|  | it is often more useful than <code>:all</code> for queries. | 
|  | Conversely, the <code>:all</code> wildcard (implicit in target | 
|  | patterns like <code>foo/...</code>) is typically more useful for | 
|  | builds. | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | <code>bazel query</code> target patterns work the same as | 
|  | <code>bazel build</code> build targets do; | 
|  | refer to <a href='bazel-user-manual.html#target-patterns'>Target Patterns</a> | 
|  | in the Bazel User Manual for further details, or type <code>bazel | 
|  | help target-syntax</code>. | 
|  |  | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | Target patterns may evaluate to a singleton set (in the case of a | 
|  | label), to a set containing many elements (as in the case of | 
|  | <code>foo/...</code>, which has thousands of elements) or to the | 
|  | empty set, if the target pattern matches no targets. | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | All nodes in the result of a target pattern expression are correctly | 
|  | ordered relative to each other according to the dependency relation. | 
|  | So, the result of <code>foo:*</code> is not just the set of targets | 
|  | in package <code>foo</code>, it is also the <em>graph</em> over | 
|  | those targets.  (No guarantees are made about the relative ordering | 
|  | of the result nodes against other nodes.)  See the section | 
|  | on <a href='#graph-order'>graph order</a> for more details. | 
|  | </p> | 
|  |  | 
|  | <h3 id="variables">Variables</h3> | 
|  | <pre>expr ::= let <var>name</var> = <var>expr</var><sub>1</sub> in <var>expr</var><sub>2</sub> | 
|  | | <var>$name</var></pre> | 
|  | <p> | 
|  | The Bazel query language allows definitions of and references to | 
|  | variables.  The | 
|  | result of evaluation of a <code>let</code> expression is the same as | 
|  | that of <var>expr</var><sub>2</sub>, with all free occurrences of | 
|  | variable <var>name</var> replaced by the value of | 
|  | <var>expr</var><sub>1</sub>. | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | For example, <code>let v = foo/... in allpaths($v, //common) | 
|  | intersect $v</code> is equivalent to the <code>allpaths(foo/..., | 
|  | //common) intersect foo/...</code>. | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | An occurrence of a variable reference <code>name</code> other than in | 
|  | an enclosing <code>let <var>name</var> = ...</code> expression is an | 
|  | error.  In other words, toplevel query expressions cannot have free | 
|  | variables. | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | In the above grammar productions, <code>name</code> is like | 
|  | <em>word</em>, but with the additional constraint that it be a legal | 
|  | identifier in the C programming language. References to the variable | 
|  | must be prepended with the "$" character. | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | Each <code>let</code> expression defines only a single variable, | 
|  | but you can nest them. | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | (Both <a | 
|  | href='#target-patterns'>target patterns</a> and variable references | 
|  | consist of just a single token, a word, creating a syntactic | 
|  | ambiguity.  However, there is no semantic ambiguity, because the | 
|  | subset of words that are legal variable names is disjoint from the | 
|  | subset of words that are legal target patterns.) | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | (Technically speaking, <code>let</code> expressions do not increase | 
|  | the expressiveness of the query language: any query expressible in | 
|  | the language can also be expressed without them.  However, they | 
|  | improve the conciseness of many queries, and may also lead to more | 
|  | efficient query evaluation.) | 
|  | </p> | 
|  |  | 
|  | <h3 id="parentheses">Parenthesized expressions</h3> | 
|  | <pre>expr ::= (<var>expr</var>)</pre> | 
|  |  | 
|  | <p> | 
|  | Parentheses associate subexpressions to force an | 
|  | order of evaluation. | 
|  | A parenthesized expression evaluates | 
|  | to the value of its argument. | 
|  | </p> | 
|  |  | 
|  | <h3 id="set-operations">Algebraic set operations: | 
|  | intersection, union, set difference</h3> | 
|  |  | 
|  | <pre>expr ::= <var>expr</var> intersect <var>expr</var> | 
|  | | <var>expr</var> ^ <var>expr</var> | 
|  | | <var>expr</var> union <var>expr</var> | 
|  | | <var>expr</var> + <var>expr</var> | 
|  | | <var>expr</var> except <var>expr</var> | 
|  | | <var>expr</var> - <var>expr</var> | 
|  | </pre> | 
|  |  | 
|  | <p> | 
|  | These three operators compute the usual set operations over their | 
|  | arguments.  Each operator has two forms, a nominal form such | 
|  | as <code>intersect</code> and a symbolic form such | 
|  | as <code>^</code>.  Both forms are equivalent; | 
|  | the symbolic forms are quicker to type.  (For clarity, the rest of | 
|  | this manual uses the nominal forms.)  For example, | 
|  | </p> | 
|  |  | 
|  | <pre>foo/... except foo/bar/...</pre> | 
|  |  | 
|  | evaluates to the set of targets that match | 
|  | <code>foo/...</code> but not | 
|  | <code>foo/bar/...</code> .  Equivalently: | 
|  |  | 
|  | <pre>foo/... - foo/bar/...</pre> | 
|  |  | 
|  | The <code>intersect</code> (<code>^</code>) | 
|  | and <code>union</code> (<code>+</code>) operations are commutative | 
|  | (symmetric); <code>except</code> (<code>-</code>) is | 
|  | asymmetric.  The parser treats all three operators as | 
|  | left-associative and of equal precedence, so you might want parentheses. | 
|  | For example, the first two of these expressions are | 
|  | equivalent, but the third is not: | 
|  |  | 
|  | <pre>x intersect y union z | 
|  | (x intersect y) union z | 
|  | x intersect (y union z)</pre> | 
|  |  | 
|  | <p> | 
|  | (We strongly recommend that you use parentheses where there is | 
|  | any danger of ambiguity in reading a query expression.) | 
|  | </p> | 
|  |  | 
|  | <h3 id="set">Read targets from an external source: set</h3> | 
|  | <pre>expr ::= set(<var>word</var> *) </pre> | 
|  | <p> | 
|  | The <code>set(<var>a</var> <var>b</var> <var>c</var> ...)</code> | 
|  | operator computes the union of a set of zero or | 
|  | more <a href='#target-patterns'>target patterns</a>, separated by | 
|  | whitespace (no commas). | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | In conjunction with the Bourne shell's <code>$(...)</code> | 
|  | feature, <code>set()</code> provides a means of saving the results | 
|  | of one query in a regular text file, manipulating that text file | 
|  | using other programs (e.g. standard UNIX shell tools), and then | 
|  | introducing the result back into the query tool as a value for | 
|  | further processing.  For example: | 
|  | </p> | 
|  | <pre> | 
|  | % bazel query deps(//my:target) --output=label | grep ... | sed ... | awk ... > foo | 
|  | % bazel query "kind(cc_binary, set($(<foo)))" | 
|  | </pre> | 
|  | <p> | 
|  | In the next example, <code>kind(cc_library, | 
|  | deps(//some_dir/foo:main, 5))</code> is effectively computed | 
|  | by filtering on the <code>maxrank</code> values using | 
|  | an <code>awk</code> program. | 
|  | </p> | 
|  | <pre> | 
|  | % bazel query 'deps(//some_dir/foo:main)' --output maxrank | | 
|  | awk '($1 < 5) { print $2;} ' > foo | 
|  | % bazel query "kind(cc_library, set($(<foo)))" | 
|  | </pre> | 
|  | <p> | 
|  | In these examples, <code>$(<foo)</code> is a shorthand | 
|  | for <code>$(cat foo)</code>, but shell commands other | 
|  | than <code>cat</code> may be used too—such as | 
|  | the previous <code>awk</code> command. | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | Note, <code>set()</code> introduces no graph ordering constraints, | 
|  | so path information may be lost when saving and reloading sets of | 
|  | nodes using it.  See the <a href='#graph-order'>graph order</a> | 
|  | section below for more detail. | 
|  | </p> | 
|  |  | 
|  | <h3 id="deps">Transitive closure of dependencies: deps</h3> | 
|  | <pre>expr ::= deps(<var>expr</var>) | 
|  | | deps(<var>expr</var>, <var>depth</var>)</pre> | 
|  | <p> | 
|  | The <code>deps(<var>x</var>)</code> operator evaluates to the graph | 
|  | formed by the transitive closure of dependencies of its argument set | 
|  | <var>x</var>. For example, the value of <code>deps(//foo)</code> is | 
|  | the dependency graph rooted at the single node <code>foo</code>, | 
|  | including all its dependencies. The value of | 
|  | <code>deps(foo/...)</code> is the dependency graphs whose roots are | 
|  | all rules in every package beneath the <code>foo</code> directory. | 
|  | Please note that 'dependencies' means only rule and file targets | 
|  | in this context, therefore the BUILD, | 
|  |  | 
|  | and Skylark files needed to | 
|  | create these targets are not included here. For that you should use the | 
|  | <a href="#buildfiles"><code>buildfiles</code></a> operator. | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | The resulting graph is ordered according to the dependency relation. | 
|  | See the section on <a href='#graph-order'>graph order</a> for more | 
|  | details. | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | The <code>deps</code> operator accepts an optional second argument, | 
|  | which is an integer literal specifying an upper bound on the depth | 
|  | of the search.  So <code>deps(foo:*, 1)</code> evaluates to all the | 
|  | direct prerequisites of any target in the <code>foo</code> package, | 
|  | and <code>deps(foo:*, 2)</code> further includes the nodes directly | 
|  | reachable from the nodes in <code>deps(foo:*, 1)</code>, and so on. | 
|  | (These numbers correspond to the ranks shown in | 
|  | the <a href='#output-ranked'><code>minrank</code></a> output | 
|  | format.)  If the <var>depth</var> parameter is omitted, the search | 
|  | is unbounded, i.e. it computes the reflexive transitive closure of | 
|  | prerequsites. | 
|  | </p> | 
|  |  | 
|  | <h3 id="rdeps">Transitive closure of reverse dependencies: rdeps</h3> | 
|  | <pre>expr ::= rdeps(<var>expr</var>, <var>expr</var>) | 
|  | | rdeps(<var>expr</var>, <var>expr</var>, <var>depth</var>)</pre> | 
|  | <p> | 
|  | The <code>rdeps(<var>u</var>, <var>x</var>)</code> operator evaluates | 
|  | to the reverse dependencies of the argument set <var>x</var> within the | 
|  | transitive closure of the universe set <var>u</var>. | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | The resulting graph is ordered according to the dependency relation.  See the | 
|  | section on <a href='#graph-order'>graph order</a> for more details. | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | The <code>rdeps</code> operator accepts an optional third argument, | 
|  | which is an integer literal specifying an upper bound on the depth of the | 
|  | search.  The resulting graph will only include nodes within a distance of the | 
|  | specified depth from any node in the argument set.  So | 
|  | <code>rdeps(//foo, //common, 1)</code> evaluates to all nodes in the | 
|  | transitive closure of <code>//foo</code> that directly depend on | 
|  | <code>//common</code>.  (These numbers correspond to the ranks shown in the | 
|  | <a href='#output-ranked'><code>minrank</code></a> output format.)  If the | 
|  | <var>depth</var> parameter is omitted, the search is unbounded. | 
|  | </p> | 
|  |  | 
|  | <h3 id="some">Arbitrary choice: some</h3> | 
|  | <pre>expr ::= some(<var>expr</var>)</pre> | 
|  | <p> | 
|  | The <code>some(<var>x</var>)</code> operator selects one target | 
|  | arbitrarily from its argument set <var>x</var>, and evaluates to a | 
|  | singleton set containing only that target.  For example, the | 
|  | expression <code>some(//foo:main union //bar:baz)</code> | 
|  | evaluates to a set containing either <code>//foo:main</code> or | 
|  | <code>//bar:baz</code>—though which one is not defined. | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | If the argument is a singleton, then <code>some</code> | 
|  | computes the identity function: <code>some(//foo:main)</code> is | 
|  | equivalent to <code>//foo:main</code>. | 
|  |  | 
|  | It is an error if the specified argument set is empty, as in the | 
|  | expression <code>some(//foo:main intersect //bar:baz)</code>. | 
|  | </p> | 
|  |  | 
|  | <h3 id="path-operators">Path operators: somepath, allpaths</h3> | 
|  | <pre>expr ::= somepath(<var>expr</var>, <var>expr</var>) | 
|  | | allpaths(<var>expr</var>, <var>expr</var>)</pre> | 
|  | <p> | 
|  | The <code>somepath(<var>S</var>, <var>E</var>)</code> and | 
|  | <code>allpaths(<var>S</var>, <var>E</var>)</code> operators compute | 
|  | paths between two sets of targets.  Both queries accept two | 
|  | arguments, a set <var>S</var> of starting points and a set | 
|  | <var>E</var> of ending points.  <code>somepath</code> returns the | 
|  | graph of nodes on <em>some</em> arbitrary path from a target in | 
|  | <var>S</var> to a target in <var>E</var>; <code>allpaths</code> | 
|  | returns the graph of nodes on <em>all</em> paths from any target in | 
|  | <var>S</var> to any target in <var>E</var>. | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | The resulting graphs are ordered according to the dependency relation. | 
|  | See the section on <a href='#graph-order'>graph order</a> for more | 
|  | details. | 
|  | </p> | 
|  |  | 
|  | <table style='margin: auto'><tr> | 
|  | <td style='text-align: center'> | 
|  | <svg width="153pt" height="288pt" | 
|  | viewBox="0.00 0.00 153.40 288.00" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"> | 
|  | <g id="graph0" class="graph" transform="scale(0.839179 0.839179) rotate(0) translate(4 339.193)"> | 
|  | <title>somepath1</title> | 
|  | <polygon fill="white" stroke="transparent" points="-4,4 -4,-339.193 178.798,-339.193 178.798,4 -4,4"/> | 
|  | <!-- n1 --> | 
|  | <g id="node1" class="node"> | 
|  | <title>n1</title> | 
|  | <ellipse fill="none" stroke="black" cx="40" cy="-314.394" rx="18" ry="18"/> | 
|  | </g> | 
|  | <!-- n2 --> | 
|  | <g id="node2" class="node"> | 
|  | <title>n2</title> | 
|  | <ellipse fill="pink" stroke="black" cx="41" cy="-236.798" rx="18" ry="18"/> | 
|  | </g> | 
|  | <!-- n1->n2 --> | 
|  | <g id="edge1" class="edge"> | 
|  | <title>n1->n2</title> | 
|  | <path fill="none" stroke="black" d="M40.2269,-296.24C40.3484,-287.058 40.5009,-275.531 40.6382,-265.147"/> | 
|  | <polygon fill="black" stroke="black" points="44.1413,-264.93 40.774,-254.884 37.1419,-264.837 44.1413,-264.93"/> | 
|  | </g> | 
|  | <!-- n3 --> | 
|  | <g id="node3" class="node"> | 
|  | <title>n3</title> | 
|  | <ellipse fill="pink" stroke="black" cx="18" cy="-162" rx="18" ry="18"/> | 
|  | </g> | 
|  | <!-- n2->n3 --> | 
|  | <g id="edge2" class="edge"> | 
|  | <title>n2->n3</title> | 
|  | <path fill="none" stroke="black" d="M35.7809,-219.279C32.9579,-210.344 29.4064,-199.103 26.2211,-189.021"/> | 
|  | <polygon fill="black" stroke="black" points="29.5485,-187.935 23.1984,-179.454 22.8737,-190.044 29.5485,-187.935"/> | 
|  | </g> | 
|  | <!-- n10 --> | 
|  | <g id="node10" class="node"> | 
|  | <title>n10</title> | 
|  | <ellipse fill="pink" stroke="black" cx="37" cy="-90" rx="18" ry="18"/> | 
|  | </g> | 
|  | <!-- n2->n10 --> | 
|  | <g id="edge9" class="edge"> | 
|  | <title>n2->n10</title> | 
|  | <path fill="none" stroke="black" d="M42.9371,-218.86C44.7656,-200.425 46.9578,-170.088 45,-144 44.3634,-135.518 43.1616,-126.336 41.8792,-118.036"/> | 
|  | <polygon fill="black" stroke="black" points="45.3237,-117.412 40.2483,-108.112 38.4164,-118.547 45.3237,-117.412"/> | 
|  | </g> | 
|  | <!-- n3->n10 --> | 
|  | <g id="edge10" class="edge"> | 
|  | <title>n3->n10</title> | 
|  | <path fill="none" stroke="black" d="M22.5027,-144.411C24.7033,-136.304 27.404,-126.354 29.8755,-117.248"/> | 
|  | <polygon fill="black" stroke="black" points="33.2878,-118.038 32.5296,-107.47 26.5322,-116.204 33.2878,-118.038"/> | 
|  | </g> | 
|  | <!-- n4 --> | 
|  | <g id="node4" class="node"> | 
|  | <title>n4</title> | 
|  | <ellipse fill="pink" stroke="black" cx="87" cy="-18" rx="18" ry="18"/> | 
|  | <text text-anchor="middle" x="87" y="-14.3" font-family="arial" font-size="14.00">E</text> | 
|  | </g> | 
|  | <!-- n5 --> | 
|  | <g id="node5" class="node"> | 
|  | <title>n5</title> | 
|  | <ellipse fill="none" stroke="black" cx="97" cy="-236.798" rx="18" ry="18"/> | 
|  | </g> | 
|  | <!-- n6 --> | 
|  | <g id="node6" class="node"> | 
|  | <title>n6</title> | 
|  | <ellipse fill="none" stroke="black" cx="121" cy="-162" rx="18" ry="18"/> | 
|  | </g> | 
|  | <!-- n5->n6 --> | 
|  | <g id="edge5" class="edge"> | 
|  | <title>n5->n6</title> | 
|  | <path fill="none" stroke="black" d="M102.446,-219.279C105.413,-210.281 109.15,-198.944 112.492,-188.808"/> | 
|  | <polygon fill="black" stroke="black" points="115.851,-189.796 115.658,-179.203 109.203,-187.604 115.851,-189.796"/> | 
|  | </g> | 
|  | <!-- n6->n4 --> | 
|  | <g id="edge6" class="edge"> | 
|  | <title>n6->n4</title> | 
|  | <path fill="none" stroke="black" d="M115.99,-144.365C112.931,-133.96 109.038,-120.252 106,-108 100.867,-87.3 95.8646,-63.6851 92.2822,-45.9844"/> | 
|  | <polygon fill="black" stroke="black" points="95.6398,-44.9258 90.2466,-35.8064 88.7758,-46.2987 95.6398,-44.9258"/> | 
|  | </g> | 
|  | <!-- n9 --> | 
|  | <g id="node9" class="node"> | 
|  | <title>n9</title> | 
|  | <ellipse fill="none" stroke="black" cx="133" cy="-90" rx="18" ry="18"/> | 
|  | </g> | 
|  | <!-- n6->n9 --> | 
|  | <g id="edge8" class="edge"> | 
|  | <title>n6->n9</title> | 
|  | <path fill="none" stroke="black" d="M123.905,-144.055C125.261,-136.145 126.907,-126.54 128.425,-117.688"/> | 
|  | <polygon fill="black" stroke="black" points="131.882,-118.237 130.122,-107.789 124.982,-117.054 131.882,-118.237"/> | 
|  | </g> | 
|  | <!-- n7 --> | 
|  | <g id="node7" class="node"> | 
|  | <title>n7</title> | 
|  | <ellipse fill="pink" stroke="black" cx="97" cy="-314.394" rx="20.5982" ry="20.5982"/> | 
|  | <text text-anchor="middle" x="97" y="-310.694" font-family="arial" font-size="14.00">S1</text> | 
|  | </g> | 
|  | <!-- n7->n2 --> | 
|  | <g id="edge4" class="edge"> | 
|  | <title>n7->n2</title> | 
|  | <path fill="none" stroke="black" d="M84.8488,-296.991C76.7726,-286.089 66.0734,-271.646 57.2656,-259.756"/> | 
|  | <polygon fill="black" stroke="black" points="60.0158,-257.588 51.2509,-251.636 54.391,-261.755 60.0158,-257.588"/> | 
|  | </g> | 
|  | <!-- n7->n5 --> | 
|  | <g id="edge3" class="edge"> | 
|  | <title>n7->n5</title> | 
|  | <path fill="none" stroke="black" d="M97,-293.532C97,-284.887 97,-274.612 97,-265.254"/> | 
|  | <polygon fill="black" stroke="black" points="100.5,-265.213 97,-255.213 93.5001,-265.213 100.5,-265.213"/> | 
|  | </g> | 
|  | <!-- n8 --> | 
|  | <g id="node8" class="node"> | 
|  | <title>n8</title> | 
|  | <ellipse fill="none" stroke="black" cx="154" cy="-236.798" rx="20.5982" ry="20.5982"/> | 
|  | <text text-anchor="middle" x="154" y="-233.098" font-family="arial" font-size="14.00">S2</text> | 
|  | </g> | 
|  | <!-- n8->n6 --> | 
|  | <g id="edge7" class="edge"> | 
|  | <title>n8->n6</title> | 
|  | <path fill="none" stroke="black" d="M145.673,-217.428C141.606,-208.456 136.653,-197.53 132.254,-187.827"/> | 
|  | <polygon fill="black" stroke="black" points="135.411,-186.313 128.095,-178.651 129.036,-189.204 135.411,-186.313"/> | 
|  | </g> | 
|  | <!-- n10->n4 --> | 
|  | <g id="edge11" class="edge"> | 
|  | <title>n10->n4</title> | 
|  | <path fill="none" stroke="black" d="M47.1182,-74.8345C53.9632,-65.2515 63.1483,-52.3924 70.9784,-41.4303"/> | 
|  | <polygon fill="black" stroke="black" points="73.9325,-43.3162 76.8968,-33.1445 68.2363,-39.2475 73.9325,-43.3162"/> | 
|  | </g> | 
|  | <!-- n11 --> | 
|  | <g id="node11" class="node"> | 
|  | <title>n11</title> | 
|  | <ellipse fill="none" stroke="black" cx="33" cy="-18" rx="18" ry="18"/> | 
|  | </g> | 
|  | <!-- n10->n11 --> | 
|  | <g id="edge12" class="edge"> | 
|  | <title>n10->n11</title> | 
|  | <path fill="none" stroke="black" d="M36.0112,-71.6966C35.5704,-63.9827 35.0407,-54.7125 34.5493,-46.1124"/> | 
|  | <polygon fill="black" stroke="black" points="38.0423,-45.8883 33.9774,-36.1043 31.0537,-46.2878 38.0423,-45.8883"/> | 
|  | </g> | 
|  | </g> | 
|  | </svg> | 
|  | <p><code>somepath(S1 + S2, E)</code>,<br/>one possible result.</p> | 
|  | </td> | 
|  | <td style='padding: 40px; text-align: center'> | 
|  | <svg width="153pt" height="288pt" | 
|  | viewBox="0.00 0.00 153.40 288.00" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"> | 
|  | <g id="graph0" class="graph" transform="scale(0.839179 0.839179) rotate(0) translate(4 339.193)"> | 
|  | <title>somepath2</title> | 
|  | <polygon fill="white" stroke="transparent" points="-4,4 -4,-339.193 178.798,-339.193 178.798,4 -4,4"/> | 
|  | <!-- n1 --> | 
|  | <g id="node1" class="node"> | 
|  | <title>n1</title> | 
|  | <ellipse fill="none" stroke="black" cx="40" cy="-314.394" rx="18" ry="18"/> | 
|  | </g> | 
|  | <!-- n2 --> | 
|  | <g id="node2" class="node"> | 
|  | <title>n2</title> | 
|  | <ellipse fill="none" stroke="black" cx="41" cy="-236.798" rx="18" ry="18"/> | 
|  | </g> | 
|  | <!-- n1->n2 --> | 
|  | <g id="edge1" class="edge"> | 
|  | <title>n1->n2</title> | 
|  | <path fill="none" stroke="black" d="M40.2269,-296.24C40.3484,-287.058 40.5009,-275.531 40.6382,-265.147"/> | 
|  | <polygon fill="black" stroke="black" points="44.1413,-264.93 40.774,-254.884 37.1419,-264.837 44.1413,-264.93"/> | 
|  | </g> | 
|  | <!-- n3 --> | 
|  | <g id="node3" class="node"> | 
|  | <title>n3</title> | 
|  | <ellipse fill="none" stroke="black" cx="18" cy="-162" rx="18" ry="18"/> | 
|  | </g> | 
|  | <!-- n2->n3 --> | 
|  | <g id="edge2" class="edge"> | 
|  | <title>n2->n3</title> | 
|  | <path fill="none" stroke="black" d="M35.7809,-219.279C32.9579,-210.344 29.4064,-199.103 26.2211,-189.021"/> | 
|  | <polygon fill="black" stroke="black" points="29.5485,-187.935 23.1984,-179.454 22.8737,-190.044 29.5485,-187.935"/> | 
|  | </g> | 
|  | <!-- n10 --> | 
|  | <g id="node10" class="node"> | 
|  | <title>n10</title> | 
|  | <ellipse fill="none" stroke="black" cx="37" cy="-90" rx="18" ry="18"/> | 
|  | </g> | 
|  | <!-- n2->n10 --> | 
|  | <g id="edge9" class="edge"> | 
|  | <title>n2->n10</title> | 
|  | <path fill="none" stroke="black" d="M42.9371,-218.86C44.7656,-200.425 46.9578,-170.088 45,-144 44.3634,-135.518 43.1616,-126.336 41.8792,-118.036"/> | 
|  | <polygon fill="black" stroke="black" points="45.3237,-117.412 40.2483,-108.112 38.4164,-118.547 45.3237,-117.412"/> | 
|  | </g> | 
|  | <!-- n3->n10 --> | 
|  | <g id="edge10" class="edge"> | 
|  | <title>n3->n10</title> | 
|  | <path fill="none" stroke="black" d="M22.5027,-144.411C24.7033,-136.304 27.404,-126.354 29.8755,-117.248"/> | 
|  | <polygon fill="black" stroke="black" points="33.2878,-118.038 32.5296,-107.47 26.5322,-116.204 33.2878,-118.038"/> | 
|  | </g> | 
|  | <!-- n4 --> | 
|  | <g id="node4" class="node"> | 
|  | <title>n4</title> | 
|  | <ellipse fill="pink" stroke="black" cx="87" cy="-18" rx="18" ry="18"/> | 
|  | <text text-anchor="middle" x="87" y="-14.3" font-family="arial" font-size="14.00">E</text> | 
|  | </g> | 
|  | <!-- n5 --> | 
|  | <g id="node5" class="node"> | 
|  | <title>n5</title> | 
|  | <ellipse fill="none" stroke="black" cx="97" cy="-236.798" rx="18" ry="18"/> | 
|  | </g> | 
|  | <!-- n6 --> | 
|  | <g id="node6" class="node"> | 
|  | <title>n6</title> | 
|  | <ellipse fill="pink" stroke="black" cx="121" cy="-162" rx="18" ry="18"/> | 
|  | </g> | 
|  | <!-- n5->n6 --> | 
|  | <g id="edge5" class="edge"> | 
|  | <title>n5->n6</title> | 
|  | <path fill="none" stroke="black" d="M102.446,-219.279C105.413,-210.281 109.15,-198.944 112.492,-188.808"/> | 
|  | <polygon fill="black" stroke="black" points="115.851,-189.796 115.658,-179.203 109.203,-187.604 115.851,-189.796"/> | 
|  | </g> | 
|  | <!-- n6->n4 --> | 
|  | <g id="edge6" class="edge"> | 
|  | <title>n6->n4</title> | 
|  | <path fill="none" stroke="black" d="M115.99,-144.365C112.931,-133.96 109.038,-120.252 106,-108 100.867,-87.3 95.8646,-63.6851 92.2822,-45.9844"/> | 
|  | <polygon fill="black" stroke="black" points="95.6398,-44.9258 90.2466,-35.8064 88.7758,-46.2987 95.6398,-44.9258"/> | 
|  | </g> | 
|  | <!-- n9 --> | 
|  | <g id="node9" class="node"> | 
|  | <title>n9</title> | 
|  | <ellipse fill="none" stroke="black" cx="133" cy="-90" rx="18" ry="18"/> | 
|  | </g> | 
|  | <!-- n6->n9 --> | 
|  | <g id="edge8" class="edge"> | 
|  | <title>n6->n9</title> | 
|  | <path fill="none" stroke="black" d="M123.905,-144.055C125.261,-136.145 126.907,-126.54 128.425,-117.688"/> | 
|  | <polygon fill="black" stroke="black" points="131.882,-118.237 130.122,-107.789 124.982,-117.054 131.882,-118.237"/> | 
|  | </g> | 
|  | <!-- n7 --> | 
|  | <g id="node7" class="node"> | 
|  | <title>n7</title> | 
|  | <ellipse fill="none" stroke="black" cx="97" cy="-314.394" rx="20.5982" ry="20.5982"/> | 
|  | <text text-anchor="middle" x="97" y="-310.694" font-family="arial" font-size="14.00">S1</text> | 
|  | </g> | 
|  | <!-- n7->n2 --> | 
|  | <g id="edge4" class="edge"> | 
|  | <title>n7->n2</title> | 
|  | <path fill="none" stroke="black" d="M84.8488,-296.991C76.7726,-286.089 66.0734,-271.646 57.2656,-259.756"/> | 
|  | <polygon fill="black" stroke="black" points="60.0158,-257.588 51.2509,-251.636 54.391,-261.755 60.0158,-257.588"/> | 
|  | </g> | 
|  | <!-- n7->n5 --> | 
|  | <g id="edge3" class="edge"> | 
|  | <title>n7->n5</title> | 
|  | <path fill="none" stroke="black" d="M97,-293.532C97,-284.887 97,-274.612 97,-265.254"/> | 
|  | <polygon fill="black" stroke="black" points="100.5,-265.213 97,-255.213 93.5001,-265.213 100.5,-265.213"/> | 
|  | </g> | 
|  | <!-- n8 --> | 
|  | <g id="node8" class="node"> | 
|  | <title>n8</title> | 
|  | <ellipse fill="pink" stroke="black" cx="154" cy="-236.798" rx="20.5982" ry="20.5982"/> | 
|  | <text text-anchor="middle" x="154" y="-233.098" font-family="arial" font-size="14.00">S2</text> | 
|  | </g> | 
|  | <!-- n8->n6 --> | 
|  | <g id="edge7" class="edge"> | 
|  | <title>n8->n6</title> | 
|  | <path fill="none" stroke="black" d="M145.673,-217.428C141.606,-208.456 136.653,-197.53 132.254,-187.827"/> | 
|  | <polygon fill="black" stroke="black" points="135.411,-186.313 128.095,-178.651 129.036,-189.204 135.411,-186.313"/> | 
|  | </g> | 
|  | <!-- n10->n4 --> | 
|  | <g id="edge11" class="edge"> | 
|  | <title>n10->n4</title> | 
|  | <path fill="none" stroke="black" d="M47.1182,-74.8345C53.9632,-65.2515 63.1483,-52.3924 70.9784,-41.4303"/> | 
|  | <polygon fill="black" stroke="black" points="73.9325,-43.3162 76.8968,-33.1445 68.2363,-39.2475 73.9325,-43.3162"/> | 
|  | </g> | 
|  | <!-- n11 --> | 
|  | <g id="node11" class="node"> | 
|  | <title>n11</title> | 
|  | <ellipse fill="none" stroke="black" cx="33" cy="-18" rx="18" ry="18"/> | 
|  | </g> | 
|  | <!-- n10->n11 --> | 
|  | <g id="edge12" class="edge"> | 
|  | <title>n10->n11</title> | 
|  | <path fill="none" stroke="black" d="M36.0112,-71.6966C35.5704,-63.9827 35.0407,-54.7125 34.5493,-46.1124"/> | 
|  | <polygon fill="black" stroke="black" points="38.0423,-45.8883 33.9774,-36.1043 31.0537,-46.2878 38.0423,-45.8883"/> | 
|  | </g> | 
|  | </g> | 
|  | </svg> | 
|  | <p><code>somepath(S1 + S2, E)</code>,<br/>another possible result.</p> | 
|  | </td> | 
|  | <td style='text-align: center'> | 
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|  | <title>n1</title> | 
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|  | <title>n2</title> | 
|  | <ellipse fill="pink" stroke="black" cx="41" cy="-236.798" rx="18" ry="18"/> | 
|  | </g> | 
|  | <!-- n1->n2 --> | 
|  | <g id="edge1" class="edge"> | 
|  | <title>n1->n2</title> | 
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|  | <g id="node3" class="node"> | 
|  | <title>n3</title> | 
|  | <ellipse fill="pink" stroke="black" cx="18" cy="-162" rx="18" ry="18"/> | 
|  | </g> | 
|  | <!-- n2->n3 --> | 
|  | <g id="edge2" class="edge"> | 
|  | <title>n2->n3</title> | 
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|  | </g> | 
|  | <!-- n10 --> | 
|  | <g id="node10" class="node"> | 
|  | <title>n10</title> | 
|  | <ellipse fill="pink" stroke="black" cx="37" cy="-90" rx="18" ry="18"/> | 
|  | </g> | 
|  | <!-- n2->n10 --> | 
|  | <g id="edge9" class="edge"> | 
|  | <title>n2->n10</title> | 
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|  | <title>n3->n10</title> | 
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|  | <!-- n4 --> | 
|  | <g id="node4" class="node"> | 
|  | <title>n4</title> | 
|  | <ellipse fill="pink" stroke="black" cx="87" cy="-18" rx="18" ry="18"/> | 
|  | <text text-anchor="middle" x="87" y="-14.3" font-family="arial" font-size="14.00">E</text> | 
|  | </g> | 
|  | <!-- n5 --> | 
|  | <g id="node5" class="node"> | 
|  | <title>n5</title> | 
|  | <ellipse fill="pink" stroke="black" cx="97" cy="-236.798" rx="18" ry="18"/> | 
|  | </g> | 
|  | <!-- n6 --> | 
|  | <g id="node6" class="node"> | 
|  | <title>n6</title> | 
|  | <ellipse fill="pink" stroke="black" cx="121" cy="-162" rx="18" ry="18"/> | 
|  | </g> | 
|  | <!-- n5->n6 --> | 
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|  | <title>n5->n6</title> | 
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|  | <title>n6->n4</title> | 
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|  | <g id="node9" class="node"> | 
|  | <title>n9</title> | 
|  | <ellipse fill="none" stroke="black" cx="133" cy="-90" rx="18" ry="18"/> | 
|  | </g> | 
|  | <!-- n6->n9 --> | 
|  | <g id="edge8" class="edge"> | 
|  | <title>n6->n9</title> | 
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|  | <title>n7</title> | 
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|  | </g> | 
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|  | <title>n7->n2</title> | 
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|  | <title>n8</title> | 
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|  | </g> | 
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|  | <g id="edge7" class="edge"> | 
|  | <title>n8->n6</title> | 
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|  | <title>n10->n4</title> | 
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|  | <title>n11</title> | 
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|  | </g> | 
|  | <!-- n10->n11 --> | 
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|  | <title>n10->n11</title> | 
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|  | </g> | 
|  | </svg> | 
|  | <p><code>allpaths(S1 + S2, E)</code>.</p> | 
|  | </td> | 
|  | </tr></table> | 
|  |  | 
|  | <h3 id="kind">Target kind filtering: kind</h3> | 
|  | <pre>expr ::= kind(<var>word</var>, <var>expr</var>) </pre> | 
|  | <p> | 
|  | The <code>kind(<var>pattern</var>, <var>input</var>)</code> operator | 
|  | applies a filter to a set of targets, and discards those targets | 
|  | that are not of the expected kind. The <var>pattern</var> parameter specifies | 
|  | what kind of target to match. | 
|  | </p> | 
|  | <ul> | 
|  | <li><b>file</b> patterns can be one of: | 
|  | <ul> | 
|  | <li><code>source file</code> | 
|  | <li><code>generated file</code> | 
|  | </ul> | 
|  | <li><b>rule</b> patterns can be one of: | 
|  | <ul> | 
|  | <li><code><var>ruletype</var> rule</code> | 
|  | <li><code><var>ruletype</var></code><br> | 
|  | Where <var>ruletype</var> is a build rule.  The difference between these | 
|  | forms is that including "rule" causes the regular expression match for | 
|  | <var>ruletype</var> to be anchored. | 
|  | </ul> | 
|  | <li><b>package group</b> patterns should simply be: | 
|  | <ul> | 
|  | <li><code>package group</code> | 
|  | </ul> | 
|  | </ul> | 
|  | <p> | 
|  | For example, the kinds for the four targets defined by the BUILD file | 
|  | (for package <code>p</code>) shown below are illustrated in the | 
|  | table: | 
|  | </p> | 
|  |  | 
|  | <table style='margin: auto'><tr><td style='padding-right:10px'> | 
|  | <pre style='margin-left: 0em;'> | 
|  | genrule( | 
|  | name = "a", | 
|  | srcs = ["a.in"], | 
|  | outs = ["a.out"], | 
|  | cmd = "...", | 
|  | ) | 
|  | </pre> | 
|  | </td><td> | 
|  | <table class="grid"> | 
|  | <tr><th>Target</th><th>Kind</th></tr> | 
|  | <tr class='tt'><td>//p:a</td><td>genrule rule</td></tr> | 
|  | <tr class='tt'><td>//p:a.in</td><td>source file</td></tr> | 
|  | <tr class='tt'><td>//p:a.out</td><td>generated file</td></tr> | 
|  | <tr class='tt'><td>//p:BUILD</td><td>source file</td></tr> | 
|  | </table> | 
|  | </td></tr></table> | 
|  |  | 
|  | <p> | 
|  | Thus, <code>kind("cc_.* rule", foo/...)</code> evaluates to the set | 
|  | of all <code>cc_library</code>, <code>cc_binary</code>, etc, | 
|  | rule targets beneath | 
|  | <code>foo</code>, and <code>kind("source file", deps(//foo))</code> | 
|  | evaluates to the set of all source files in the transitive closure | 
|  | of dependencies of the <code>//foo</code> target. | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | Quotation of the <var>pattern</var> argument is often required | 
|  | because without it, many regular expressions, such as <code>source | 
|  | file</code> and <code>.*_test</code>, are not considered words by | 
|  | the parser. | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | When matching for <code>package group</code>, targets ending in | 
|  | <code>:all</code> may not yield any results. | 
|  | Use <code>:all-targets</code> instead. | 
|  | </p> | 
|  |  | 
|  | <h3 id="filter">Target name filtering: filter</h3> | 
|  | <pre>expr ::= filter(<var>word</var>, <var>expr</var>) </pre> | 
|  | <p> | 
|  | The <code>filter(<var>pattern</var>, <var>input</var>)</code> operator | 
|  | applies a filter to a set of targets, and discards targets whose | 
|  | labels (in absolute form) do not match the pattern; it | 
|  | evaluates to a subset of its input. | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | The first argument, <var>pattern</var> is a word containing a | 
|  | regular expression over target names.  A <code>filter</code> expression | 
|  | evaluates to the set containing all targets <var>x</var> such that | 
|  | <var>x</var> is a member of the set <var>input</var> and the | 
|  | label (in absolute form, e.g. <code>//foo:bar</code>) | 
|  | of <var>x</var> contains an (unanchored) match | 
|  | for the regular expression <var>pattern</var>.  Since all | 
|  | target names start with <code>//</code>, it may be used as an alternative | 
|  | to the <code>^</code> regular expression anchor. | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | This operator often provides a much faster and more robust alternative to the | 
|  | <code>intersect</code> operator. For example, in order to see all | 
|  | <code>bar</code> dependencies of the <code>//foo:foo</code> target, one could | 
|  | evaluate | 
|  | </p> | 
|  | <pre>deps(//foo) intersect //bar/...</pre> | 
|  | <p> | 
|  | This statement, however, will require parsing of all BUILD files in the | 
|  | <code>bar</code> tree, which will be slow and prone to errors in | 
|  | irrelevant BUILD files. An alternative would be: | 
|  | </p> | 
|  | <pre>filter(//bar, deps(//foo))</pre> | 
|  | <p> | 
|  | which would first calculate the set of <code>//foo</code> dependencies and | 
|  | then would filter only targets matching the provided pattern—in other | 
|  | words, targets with names containing <code>//bar</code> as a | 
|  | substring. | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | Another common use of the <code>filter(<var>pattern</var>, | 
|  | <var>expr</var>)</code> operator is to filter specific files by their | 
|  | name or extension. For example, | 
|  | </p> | 
|  | <pre>filter("\.cc$", deps(//foo))</pre> | 
|  | <p> | 
|  | will provide a list of all <code>.cc</code> files used to build | 
|  | <code>//foo</code>. | 
|  | </p> | 
|  |  | 
|  | <h3 id="attr">Rule attribute filtering: attr</h3> | 
|  | <pre>expr ::= attr(<var>word</var>, <var>word</var>, <var>expr</var>) </pre> | 
|  | <p> | 
|  | The <code>attr(<var>name</var>, <var>pattern</var>, <var>input</var>)</code> | 
|  | operator applies a filter to a set of targets, and discards targets that | 
|  | are not rules, rule targets that do not have attribute <var>name</var> | 
|  | defined or rule targets where the attribute value does not match the provided | 
|  | regular expression <var>pattern</var>; it evaluates to a subset of its input. | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | The first argument, <var>name</var> is the name of the rule attribute that | 
|  | should be matched against the provided regular expression pattern. The second | 
|  | argument, <var>pattern</var> is a regular expression over the attribute | 
|  | values. An <code>attr</code> expression evaluates to the set containing all | 
|  | targets <var>x</var> such that  <var>x</var> is a member of the set | 
|  | <var>input</var>, is a rule with the defined attribute <var>name</var> and | 
|  | the attribute value contains an (unanchored) match for the regular expression | 
|  | <var>pattern</var>. Please note, that if <var>name</var> is an optional | 
|  | attribute and rule does not specify it explicitly then default attribute | 
|  | value will be used for comparison. For example, | 
|  | </p> | 
|  | <pre>attr(linkshared, 0, deps(//foo))</pre> | 
|  | <p> | 
|  | will select all <code>//foo</code> dependencies that are allowed to have a | 
|  | linkshared attribute (e.g., <code>cc_binary</code> rule) and have it either | 
|  | explicitly set to 0 or do not set it at all but default value is 0 (e.g. for | 
|  | <code>cc_binary</code> rules). | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | List-type attributes (such as <code>srcs</code>, <code>data</code>, etc) are | 
|  | converted to strings of the form <code>[value<sub>1</sub>, ..., value<sub>n</sub>]</code>, | 
|  | starting with a <code>[</code> bracket, ending with a <code>]</code> bracket | 
|  | and using "<code>, </code>" (comma, space) to delimit multiple values. | 
|  | Labels are converted to strings by using the absolute form of the | 
|  | label.  For example, an attribute <code>deps=[":foo", | 
|  | "//otherpkg:bar", "wiz"]</code> would be converted to the | 
|  | string <code>[//thispkg:foo, //otherpkg:bar, //thispkg:wiz]</code>. | 
|  | Brackets | 
|  | are always present, so the empty list would use string value <code>[]</code> | 
|  | for matching purposes. For example, | 
|  | </p> | 
|  | <pre>attr("srcs", "\[\]", deps(//foo))</pre> | 
|  | <p> | 
|  | will select all rules among <code>//foo</code> dependencies that have an | 
|  | empty <code>srcs</code> attribute, while | 
|  | </p> | 
|  | <pre>attr("data", ".{3,}", deps(//foo))</pre> | 
|  | <p> | 
|  | will select all rules among <code>//foo</code> dependencies that specify at | 
|  | least one value in the <code>data</code> attribute (every label is at least | 
|  | 3 characters long due to the <code>//</code> and <code>:</code>). | 
|  | </p> | 
|  |  | 
|  | <h3 id="visible">Rule visibility filtering: visible</h3> | 
|  | <pre>expr ::= visible(<var>expr</var>, <var>expr</var>) </pre> | 
|  | <p> | 
|  | The <code>visible(<var>predicate</var>, <var>input</var>)</code> operator | 
|  | applies a filter to a set of targets, and discards targets without the | 
|  | required visibility. | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | The first argument, <var>predicate</var>, is a set of targets that all targets | 
|  | in the output must be visible to. A <var>visible</var> expression | 
|  | evaluates to the set containing all targets <var>x</var> such that <var>x</var> | 
|  | is a member of the set <var>input</var>, and for all targets <var>y</var> in | 
|  | <var>predicate</var> <var>x</var> is visible to <var>y</var>. For example: | 
|  | </p> | 
|  | <pre>visible(//foo, //bar:*)</pre> | 
|  | <p> | 
|  | will select all targets in the package <code>//bar</code> that <code>//foo</code> | 
|  | can depend on without violating visibility restrictions. | 
|  | </p> | 
|  |  | 
|  | <h3 id="labels">Evaluation of rule attributes of type label: labels</h3> | 
|  | <pre>expr ::= labels(<var>word</var>, <var>expr</var>) </pre> | 
|  | <p> | 
|  | The <code>labels(<var>attr_name</var>, <var>inputs</var>)</code> | 
|  | operator returns the set of targets specified in the | 
|  | attribute <var>attr_name</var> of type "label" or "list of label" in | 
|  | some rule in set <var>inputs</var>. | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | For example, <code>labels(srcs, //foo)</code> returns the set of | 
|  | targets appearing in the <code>srcs</code> attribute of | 
|  | the <code>//foo</code> rule.  If there are multiple rules | 
|  | with <code>srcs</code> attributes in the <var>inputs</var> set, the | 
|  | union of their <code>srcs</code> is returned. | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | Please note, <code>deps</code> is a reserved word in the query | 
|  | language, so you must quote it if you wish to query the rule | 
|  | attribute of that name in a <code>labels</code> expression: | 
|  | <code>labels("deps", //foo)</code>. | 
|  | </p> | 
|  |  | 
|  | <h3 id="tests">Expand and filter test_suites: tests</h3> | 
|  | <pre>expr ::= tests(<var>expr</var>)</pre> | 
|  | <p> | 
|  | The <code>tests(<var>x</var>)</code> operator returns the set of all test | 
|  | rules in set <var>x</var>, expanding any <code>test_suite</code> rules into | 
|  | the set of individual tests that they refer to, and applying filtering by | 
|  | <code>tag</code> and <code>size</code>. | 
|  |  | 
|  | By default, query evaluation | 
|  | ignores any non-test targets in all <code>test_suite</code> rules. This can be | 
|  | changed to errors with the <code>--strict_test_suite</code> option. | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | For example, the query <code>kind(test, foo:*)</code> lists all | 
|  | the <code>*_test</code> and <code>test_suite</code> rules | 
|  | in the <code>foo</code> package.  All the results are (by | 
|  | definition) members of the <code>foo</code> package.  In contrast, | 
|  | the query <code>tests(foo:*)</code> will return all of the | 
|  | individual tests that would be executed by <code>bazel test | 
|  | foo:*</code>: this may include tests belonging to other packages, | 
|  | that are referenced directly or indirectly | 
|  | via <code>test_suite</code> rules. | 
|  | </p> | 
|  |  | 
|  |  | 
|  | <h3 id="buildfiles">Package definition files: buildfiles</h3> | 
|  | <pre>expr ::= buildfiles(<var>expr</var>)</pre> | 
|  | <p> | 
|  | The <code>buildfiles(<var>x</var>)</code> operator returns the set | 
|  | of files that define the packages of each target in | 
|  | set <var>x</var>; in other words, for each package, its BUILD file, | 
|  | plus any files it references | 
|  |  | 
|  | via <code>load</code>.  Note that this also returns the BUILD files of the | 
|  | packages containing these <code>load</code>ed files. | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | This operator is typically used when determining what files or | 
|  | packages are required to build a specified target, often in conjunction with | 
|  | the <a href='#output-package'><code>--output package</code></a> | 
|  | option, below).  For example, | 
|  | </p> | 
|  | <pre>bazel query 'buildfiles(deps(//foo))' --output package</pre> | 
|  | <p> | 
|  | returns the set of all packages on which <code>//foo</code> transitively | 
|  | depends. | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | (Note: a naive attempt at the above query would omit | 
|  | the <code>buildfiles</code> operator and use only <code>deps</code>, | 
|  | but this yields an incorrect result: while the result contains the | 
|  | majority of needed packages, those packages that contain only files | 
|  | that are <code>load()</code>'ed | 
|  |  | 
|  | will be missing. | 
|  | </p> | 
|  |  | 
|  | <h3 id="loadfiles">Package definition files: loadfiles</h3> | 
|  | <pre>expr ::= loadfiles(<var>expr</var>)</pre> | 
|  | <p> | 
|  | The <code>loadfiles(<var>x</var>)</code> operator returns the set of | 
|  | Skylark files that are needed to load the packages of each target in | 
|  | set <var>x</var>. In other words, for each package, it returns the | 
|  | .bzl files that are referenced from its BUILD files. | 
|  | </p> | 
|  |  | 
|  | <h2>Output formats</h2> | 
|  |  | 
|  | <p> | 
|  | <code>bazel query</code> generates a graph. | 
|  | You specify the content, format, and ordering by which | 
|  | <code>bazel query</code> presents this graph | 
|  | by means of the <code>--output</code> | 
|  | command-line option. | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | Some of the output formats accept additional options.  The name of | 
|  | each output option is prefixed with the output format to which it | 
|  | applies, so <code>--graph:factored</code> applies only | 
|  | when <code>--output=graph</code> is being used; it has no effect if | 
|  | an output format other than <code>graph</code> is used. Similarly, | 
|  | <code>--xml:line_numbers</code> applies only when <code>--output=xml</code> | 
|  | is being used. | 
|  | </p> | 
|  |  | 
|  | <h3 id='result-order'>On the ordering of results</h3> | 
|  |  | 
|  | <p> | 
|  | Although query expressions always follow the "<a href='#graph-order'>law of | 
|  | conservation of graph order</a>", <i>presenting</i> the results may be done | 
|  | in either a dependency-ordered or unordered manner. This does <b>not</b> | 
|  | influence the targets in the result set or how the query is computed. It only | 
|  | affects how the results are printed to stdout. Moreover, nodes that are | 
|  | equivalent in the dependency order may or may not be ordered alphabetically. | 
|  | The <code>--order_output</code> flag can be used to control this behavior. | 
|  | (The <code>--[no]order_results</code> flag has a subset of the functionality | 
|  | of the <code>--order_output</code> flag and is deprecated.) | 
|  | </p> | 
|  | <p> | 
|  | The default value of this flag is <code>auto</code>, which is equivalent to | 
|  | <code>full</code> for every output format except for <code>proto</code>, | 
|  | <code>graph</code>, <code>minrank</code>, and <code>maxrank</code>, for which | 
|  | it is equivalent to <code>deps</code>. | 
|  | </p> | 
|  | <p> | 
|  | When this flag is <code>no</code> and <code>--output</code> is one of | 
|  | <code>build</code>, <code>label</code>, <code>label_kind</code>, | 
|  | <code>location</code>, <code>package</code>, <code>proto</code>, | 
|  | <code>record</code> or <code>xml</code>, the outputs will be printed in | 
|  | arbitrary order. <b>This is generally the fastest option</b>. It is not | 
|  | supported though when <code>--output</code> is one of <code>graph</code>, | 
|  | <code>min_rank</code> or <code>max_rank</code>: with these formats, bazel will | 
|  | always print results ordered by the dependency order or rank. | 
|  | </p> | 
|  | <p> | 
|  | When this flag is <code>deps</code>, bazel will print results ordered by the | 
|  | dependency order. However, nodes that are unordered by the dependency order | 
|  | (because there is no path from either one to the other) may be printed in any | 
|  | order. | 
|  | </p> | 
|  | <p> | 
|  | When this flag is <code>full</code>, bazel will print results ordered by the | 
|  | dependency order, with unordered nodes ordered alphabetically or reverse | 
|  | alphabetically, depending on the output format. This may be slower than the | 
|  | other options, and so should only be used when deterministic results are | 
|  | important — it is guaranteed with this option that running the same query | 
|  | multiple times will always produce the same output. | 
|  | </p> | 
|  |  | 
|  | <h3 id="output-build">Print the source form of targets as they would appear in BUILD</h3> | 
|  | <pre>--output build</pre> | 
|  | <p> | 
|  | With this option, the representation of each target is as if it were | 
|  | hand-written in the BUILD language. All variables and function calls | 
|  | (e.g. glob, macros) are expanded, which is useful for seeing the effect | 
|  | of Skylark macros. Additionally, each effective rule is annotated with | 
|  | the name of the macro (if any, see <code>generator_name</code> and | 
|  | <code>generator_function</code>) that produced it. | 
|  | </p> | 
|  | <p> | 
|  | Although the output uses the same syntax as BUILD files, it is not | 
|  | guaranteed to produce a valid BUILD file. | 
|  | </p> | 
|  |  | 
|  | <h3 id="output-label">Print the label of each target</h3> | 
|  | <pre>--output label</pre> | 
|  | <p> | 
|  | With this option, the set of names (or <em>labels</em>) of each target | 
|  | in the resulting graph is printed, one label per line, in | 
|  | topological order (unless <code>--noorder_results</code> is specified, see | 
|  | <a href='#result-order'>notes on the ordering of results</a>). | 
|  | (A topological ordering is one in which a graph | 
|  | node appears earlier than all of its successors.)  Of course there | 
|  | are many possible topological orderings of a graph (<em>reverse | 
|  | postorder</em> is just one); which one is chosen is not specified. | 
|  |  | 
|  | When printing the output of a <code>somepath</code> query, the order | 
|  | in which the nodes are printed is the order of the path. | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | Caveat: in some corner cases, there may be two distinct targets with | 
|  | the same label; for example, a <code>sh_binary</code> rule and its | 
|  | sole (implicit) <code>srcs</code> file may both be called | 
|  | <code>foo.sh</code>.  If the result of a query contains both of | 
|  | these targets, the output (in <code>label</code> format) will appear | 
|  | to contain a duplicate.  When using the <code>label_kind</code> (see | 
|  | below) format, the distinction becomes clear: the two targets have | 
|  | the same name, but one has kind <code>sh_binary rule</code> and the | 
|  | other kind <code>source file</code>. | 
|  | </p> | 
|  |  | 
|  | <h3 id="output-label_kind">Print the label and kind of each target</h3> | 
|  | <pre>--output label_kind</pre> | 
|  | <p> | 
|  | Like <code>label</code>, this output format prints the labels of | 
|  | each target in the resulting graph, in topological order, but it | 
|  | additionally precedes the label by | 
|  | the <a href='#kind'><em>kind</em></a> of the target. | 
|  | </p> | 
|  |  | 
|  | <h3 id="output-ranked">Print the label of each target, in rank order</h3> | 
|  | <pre>--output minrank | 
|  | --output maxrank</pre> | 
|  | <p> | 
|  | Like <code>label</code>, the <code>minrank</code> | 
|  | and <code>maxrank</code> output formats print the labels of each | 
|  | target in the resulting graph, but instead of appearing in | 
|  | topological order, they appear in rank order, preceded by their | 
|  | rank number. These are unaffected by the result ordering | 
|  | <code>--[no]order_results</code> flag (see <a href='#result-order'>notes on | 
|  | the ordering of results</a>). | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | There are two variants of this format: <code>minrank</code> ranks | 
|  | each node by the length of the shortest path from a root node to it. | 
|  | "Root" nodes (those which have no incoming edges) are of rank 0, | 
|  | their successors are of rank 1, etc.  (As always, edges point from a | 
|  | target to its prerequisites: the targets it depends upon.) | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | <code>maxrank</code> ranks each node by the length of the longest | 
|  | path from a root node to it.  Again, "roots" have rank 0, all other | 
|  | nodes have a rank which is one greater than the maximum rank of all | 
|  | their predecessors. | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | All nodes in a cycle are considered of equal rank.  (Most graphs are | 
|  | acyclic, but cycles do occur | 
|  | simply because BUILD files contain erroneous cycles.) | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | These output formats are useful for discovering how deep a graph is. | 
|  | If used for the result of a <code>deps(x)</code>, <code>rdeps(x)</code>, | 
|  | or <code>allpaths</code> query, then the rank number is equal to the | 
|  | length of the shortest (with <code>minrank</code>) or longest | 
|  | (with <code>maxrank</code>) path from <code>x</code> to a node in | 
|  | that rank.  <code>maxrank</code> can be used to determine the | 
|  | longest sequence of build steps required to build a target. | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | Please note, the ranked output of a <code>somepath</code> query is | 
|  | basically meaningless because <code>somepath</code> doesn't | 
|  | guarantee to return either a shortest or a longest path, and it may | 
|  | include "transitive" edges from one path node to another that are | 
|  | not direct edges in original graph. | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | For example, the graph on the left yields the outputs on the right | 
|  | when <code>--output minrank</code> and <code>--output maxrank</code> | 
|  | are specified, respectively. | 
|  | </p> | 
|  |  | 
|  | <table style='margin: auto'><tr><td> | 
|  | <svg width="169pt" height="260pt" | 
|  | viewBox="0.00 0.00 169.00 260.00" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"> | 
|  | <g id="graph0" class="graph" transform="scale(1 1) rotate(0) translate(4 256)"> | 
|  | <title>mygraph</title> | 
|  | <polygon fill="white" stroke="transparent" points="-4,4 -4,-256 165,-256 165,4 -4,4"/> | 
|  | <!-- //a:a --> | 
|  | <g id="node1" class="node"> | 
|  | <title>//a:a</title> | 
|  | <polygon fill="none" stroke="black" points="65.5,-108 11.5,-108 11.5,-72 65.5,-72 65.5,-108"/> | 
|  | <text text-anchor="middle" x="38.5" y="-86.3" font-family="arial" font-size="14.00">//a:a</text> | 
|  | </g> | 
|  | <!-- //a:a.cc --> | 
|  | <g id="node2" class="node"> | 
|  | <title>//a:a.cc</title> | 
|  | <polygon fill="none" stroke="black" points="77,-36 0,-36 0,-0 77,-0 77,-36"/> | 
|  | <text text-anchor="middle" x="38.5" y="-14.3" font-family="arial" font-size="14.00">//a:a.cc</text> | 
|  | </g> | 
|  | <!-- //a:a->//a:a.cc --> | 
|  | <g id="edge1" class="edge"> | 
|  | <title>//a:a->//a:a.cc</title> | 
|  | <path fill="none" stroke="black" d="M38.5,-71.6966C38.5,-63.9827 38.5,-54.7125 38.5,-46.1124"/> | 
|  | <polygon fill="black" stroke="black" points="42.0001,-46.1043 38.5,-36.1043 35.0001,-46.1044 42.0001,-46.1043"/> | 
|  | </g> | 
|  | <!-- //b:b --> | 
|  | <g id="node3" class="node"> | 
|  | <title>//b:b</title> | 
|  | <polygon fill="none" stroke="black" points="120.5,-180 66.5,-180 66.5,-144 120.5,-144 120.5,-180"/> | 
|  | <text text-anchor="middle" x="93.5" y="-158.3" font-family="arial" font-size="14.00">//b:b</text> | 
|  | </g> | 
|  | <!-- //b:b->//a:a --> | 
|  | <g id="edge2" class="edge"> | 
|  | <title>//b:b->//a:a</title> | 
|  | <path fill="none" stroke="black" d="M79.9045,-143.697C73.3773,-135.389 65.432,-125.277 58.2534,-116.141"/> | 
|  | <polygon fill="black" stroke="black" points="60.8695,-113.805 51.9391,-108.104 55.3653,-118.13 60.8695,-113.805"/> | 
|  | </g> | 
|  | <!-- //b:b.cc --> | 
|  | <g id="node4" class="node"> | 
|  | <title>//b:b.cc</title> | 
|  | <polygon fill="none" stroke="black" points="161,-108 84,-108 84,-72 161,-72 161,-108"/> | 
|  | <text text-anchor="middle" x="122.5" y="-86.3" font-family="arial" font-size="14.00">//b:b.cc</text> | 
|  | </g> | 
|  | <!-- //b:b->//b:b.cc --> | 
|  | <g id="edge3" class="edge"> | 
|  | <title>//b:b->//b:b.cc</title> | 
|  | <path fill="none" stroke="black" d="M100.669,-143.697C103.935,-135.813 107.874,-126.304 111.502,-117.546"/> | 
|  | <polygon fill="black" stroke="black" points="114.82,-118.683 115.414,-108.104 108.353,-116.003 114.82,-118.683"/> | 
|  | </g> | 
|  | <!-- //c:c --> | 
|  | <g id="node5" class="node"> | 
|  | <title>//c:c</title> | 
|  | <polygon fill="none" stroke="black" points="92.5,-252 38.5,-252 38.5,-216 92.5,-216 92.5,-252"/> | 
|  | <text text-anchor="middle" x="65.5" y="-230.3" font-family="arial" font-size="14.00">//c:c</text> | 
|  | </g> | 
|  | <!-- //c:c->//a:a --> | 
|  | <g id="edge5" class="edge"> | 
|  | <title>//c:c->//a:a</title> | 
|  | <path fill="none" stroke="black" d="M62.2432,-215.871C57.6415,-191.67 49.188,-147.211 43.7086,-118.393"/> | 
|  | <polygon fill="black" stroke="black" points="47.0748,-117.359 41.7684,-108.189 40.198,-118.667 47.0748,-117.359"/> | 
|  | </g> | 
|  | <!-- //c:c->//b:b --> | 
|  | <g id="edge4" class="edge"> | 
|  | <title>//c:c->//b:b</title> | 
|  | <path fill="none" stroke="black" d="M72.4214,-215.697C75.5747,-207.813 79.3783,-198.304 82.8814,-189.546"/> | 
|  | <polygon fill="black" stroke="black" points="86.194,-190.689 86.6583,-180.104 79.6946,-188.089 86.194,-190.689"/> | 
|  | </g> | 
|  | </g> | 
|  | </svg> | 
|  | </td><td> | 
|  | <pre> | 
|  | minrank | 
|  |  | 
|  | 0 //c:c | 
|  | 1 //b:b | 
|  | 1 //a:a | 
|  | 2 //b:b.cc | 
|  | 2 //a:a.cc | 
|  | </pre> | 
|  | </td><td> | 
|  | <pre> | 
|  | maxrank | 
|  |  | 
|  | 0 //c:c | 
|  | 1 //b:b | 
|  | 2 //a:a | 
|  | 2 //b:b.cc | 
|  | 3 //a:a.cc | 
|  | </pre> | 
|  | </td></tr></table> | 
|  |  | 
|  | <h3 id="output-location">Print the location of each target</h3> | 
|  | <pre>--output location</pre> | 
|  | <p> | 
|  | Like <code>label_kind</code>, this option prints out, for each | 
|  | target in the result, the target's kind and label, but it is | 
|  | prefixed by a string describing the location of that target, as a | 
|  | filename and line number.  The format resembles the output of | 
|  | <code>grep</code>. Thus, tools that can parse the latter (such as Emacs | 
|  | or vi) can also use the query output to step through a series of | 
|  | matches, allowing the Bazel query tool to be used as a | 
|  | dependency-graph-aware "grep for BUILD files". | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | The location information varies by target kind (see the <a | 
|  | href='#kind'>kind</a> operator).  For rules, the | 
|  | location of the rule's declaration within the BUILD file is printed. | 
|  | For source files, the location of line 1 of the actual file is | 
|  | printed.  For a generated file, the location of the rule that | 
|  | generates it is printed.  (The query tool does not have sufficient | 
|  | information to find the actual location of the generated file, and | 
|  | in any case, it might not exist if a build has not yet been | 
|  | performed.) | 
|  | </p> | 
|  |  | 
|  | <h3 id="output-package">Print the set of packages</h3> | 
|  | <pre>--output package</pre> | 
|  | <p> | 
|  | This option prints the name of all packages to which | 
|  | some target in the result set belongs.  The names are printed in | 
|  | lexicographical order; duplicates are excluded.  Formally, this | 
|  | is a <em>projection</em> from the set of labels (package, target) onto | 
|  | packages. | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | In conjunction with the <code>deps(...)</code> query, this output | 
|  | option can be used to find the set of packages that must be checked | 
|  | out in order to build a given set of targets. | 
|  | </p> | 
|  |  | 
|  | <h3 id="output-graph">Display a graph of the result</h3> | 
|  | <pre>--output graph</pre> | 
|  | <p> | 
|  | This option causes the query result to be printed as a directed | 
|  | graph in the popular AT&T GraphViz format.  Typically the | 
|  | result is saved to a file, such as <code>.png</code> or <code>.svg</code>. | 
|  | (If the <code>dot</code> program is not installed on your workstation, you | 
|  | can install it using the command <code>sudo apt-get install graphviz</code>.) | 
|  | See the example section below for a sample invocation. | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | This output format is particularly useful for <code>allpath</code>, | 
|  | <code>deps</code>, or <code>rdeps</code> queries, where the result | 
|  | includes a <em>set of paths</em> that cannot be easily visualized when | 
|  | rendered in a linear form, such as with <code>--output label</code>. | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | By default, the graph is rendered in a <em>factored</em> form.  That is, | 
|  | topologically-equivalent nodes are merged together into a single | 
|  | node with multiple labels.  This makes the graph more compact | 
|  | and readable, because typical result graphs contain highly | 
|  | repetitive patterns.  For example, a <code>java_library</code> rule | 
|  | may depend on hundreds of Java source files all generated by the | 
|  | same <code>genrule</code>; in the factored graph, all these files | 
|  | are represented by a single node.  This behavior may be disabled | 
|  | with the <code>--nograph:factored</code> option. | 
|  | </p> | 
|  |  | 
|  | <h4><code>--graph:node_limit <var>n</var></code></h4> | 
|  | <p> | 
|  | The option specifies the maximum length of the label string for a | 
|  | graph node in the output.  Longer labels will be truncated; -1 | 
|  | disables truncation.  Due to the factored form in which graphs are | 
|  | usually printed, the node labels may be very long.  GraphViz cannot | 
|  | handle labels exceeding 1024 characters, which is the default value | 
|  | of this option.  This option has no effect unless | 
|  | <code>--output=graph</code> is being used. | 
|  | </p> | 
|  |  | 
|  | <h4><code>--[no]graph:factored</code></h4> | 
|  | <p> | 
|  | By default, graphs are displayed in factored form, as explained | 
|  | <a href='#output-graph'>above</a>. | 
|  | When <code>--nograph:factored</code> is specified, graphs are | 
|  | printed without factoring.  This makes visualization using GraphViz | 
|  | impractical, but the simpler format may ease processing by other | 
|  | tools (e.g. grep).  This option has no effect | 
|  | unless <code>--output=graph</code> is being used. | 
|  | </p> | 
|  |  | 
|  | <h3 id="output-xml">XML</h3> | 
|  | <pre>--output xml</pre> | 
|  | <p> | 
|  | This option causes the resulting targets to be printed in an XML | 
|  | form.  The output starts with an XML header such as this | 
|  | </p> | 
|  | <pre> | 
|  | <?xml version="1.0" encoding="UTF-8"?> | 
|  | <query version="2"> | 
|  | </pre> | 
|  | <!-- The docs should continue to document version 2 into perpetuity, | 
|  | even if we add new formats, to handle clients synced to old CLs. --> | 
|  | <p> | 
|  | and then continues with an XML element for each target | 
|  | in the result graph, in topological order (unless | 
|  | <a href='#result-order'>unordered results</a> are requested), | 
|  | and then finishes with a terminating | 
|  | </p> | 
|  | <pre> | 
|  | </query> | 
|  | </pre> | 
|  | <p> | 
|  | Simple entries are emitted for targets of <code>file</code> | 
|  | kind: | 
|  | </p> | 
|  | <pre> | 
|  | <source-file name='//foo:foo_main.cc' .../> | 
|  | <generated-file name='//foo:libfoo.so' .../> | 
|  | </pre> | 
|  | <p> | 
|  | But for rules, the XML is structured and contains definitions of all | 
|  | the attributes of the rule, including those whose value was not | 
|  | explicitly specified in the rule's BUILD file. | 
|  | </p> | 
|  | <p> | 
|  | Additionally, the result includes <code>rule-input</code> and | 
|  | <code>rule-output</code> elements so that the topology of the | 
|  | dependency graph can be reconstructed without having to know that, | 
|  | for example, the elements of the <code>srcs</code> attribute are | 
|  | forward dependencies (prerequisites) and the contents of the | 
|  | <code>outs</code> attribute are backward dependencies (consumers). | 
|  |  | 
|  | <code>rule-input</code> elements for <a | 
|  | href='#implicit_deps'>implicit dependencies</a> are suppressed if | 
|  | <code>--noimplicit_deps</code> is specified. | 
|  | </p> | 
|  | <pre> | 
|  | <rule class='cc_binary rule' name='//foo:foo' ...> | 
|  | <list name='srcs'> | 
|  | <label value='//foo:foo_main.cc'/> | 
|  | <label value='//foo:bar.cc'/> | 
|  | ... | 
|  | </list> | 
|  | <list name='deps'> | 
|  | <label value='//common:common'/> | 
|  | <label value='//collections:collections'/> | 
|  | ... | 
|  | </list> | 
|  | <list name='data'> | 
|  | ... | 
|  | </list> | 
|  | <int name='linkstatic' value='0'/> | 
|  | <int name='linkshared' value='0'/> | 
|  | <list name='licenses'/> | 
|  | <list name='distribs'> | 
|  | <distribution value="INTERNAL" /> | 
|  | </list> | 
|  | <rule-input name="//common:common" /> | 
|  | <rule-input name="//collections:collections" /> | 
|  | <rule-input name="//foo:foo_main.cc" /> | 
|  | <rule-input name="//foo:bar.cc" /> | 
|  | ... | 
|  | </rule> | 
|  | </pre> | 
|  |  | 
|  | <p> | 
|  | Every XML element for a target contains a <code>name</code> | 
|  | attribute, whose value is the target's label, and | 
|  | a <code>location</code> attribute, whose value is the target's | 
|  | location as printed by the <a href='output-location'><code>--output | 
|  | location</code></a>. | 
|  | </p> | 
|  |  | 
|  | <h4><code>--[no]xml:line_numbers</code></h4> | 
|  | <p> | 
|  | By default, the locations displayed in the XML output contain line numbers. | 
|  | When <code>--noxml:line_numbers</code> is specified, line numbers are not | 
|  | printed. | 
|  | </p> | 
|  |  | 
|  | <h4><code>--[no]xml:default_values</code></h4> | 
|  | <p> | 
|  | By default, XML output does not include rule attribute whose value | 
|  | is the default value for that kind of attribute (e.g. because it | 
|  | were not specified in the BUILD file, or the default value was | 
|  | provided explicitly).  This option causes such attribute values to | 
|  | be included in the XML output. | 
|  | </p> | 
|  |  | 
|  |  | 
|  | <h3 id="external-repos">Querying with external repositories</h3> | 
|  |  | 
|  | <p> | 
|  | If the build depends on rules from external repositories (defined in the | 
|  | WORKSPACE file) then query results will include these dependencies. For | 
|  | example, if <code>//foo:bar</code> depends on <code>//external:some-lib</code> | 
|  | and <code>//external:some-lib</code> is bound to | 
|  | <code>@other-repo//baz:lib</code>, then | 
|  | <code>bazel query 'deps(//foo:bar)'</code> | 
|  | will list both <code>@other-repo//baz:lib</code> and | 
|  | <code>//external:some-lib</code> as dependencies. | 
|  | </p> | 
|  |  | 
|  | <p> | 
|  | External repositories themselves are not dependencies of a build. That is, in | 
|  | the example above, <code>//external:other-repo</code> is not a dependency. It | 
|  | can be queried for as a member of the <code>//external</code> package, though, | 
|  | for example: | 
|  | <p> | 
|  |  | 
|  | <pre> | 
|  | $ # Querying over all members of //external returns the repository. | 
|  | $ bazel query 'kind(maven_jar, //external:*)' | 
|  | //external:other-repo | 
|  |  | 
|  | $ # ...but the repository is not a dependency. | 
|  | $ bazel query 'kind(maven_jar, deps(//foo:bar))' | 
|  | INFO: Empty results | 
|  | </pre> |