Make PackageOutputFormatter use PackageIdentifier instead of package name.

Fixes bazelbuild#3122.

RELNOTES: bazel query --output package now displays packages from external repository with the format "@reponame//package". Packages in the main repository continue to have the format "package".
PiperOrigin-RevId: 158327492

Author: aj-michael

site/docs/query.html

@@ -1231,63 +1231,10 @@ <h3 id="output-package">Print the set of packages</h3>
 </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.
+  Packages in external repositories are formatted as
+  <code>@repo//foo/bar</code> while packages in the main repository are
+  formatted as <code>foo/bar</code>.
 </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&amp;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>

src/main/java/com/google/devtools/build/lib/query2/output/OutputFormatter.java

@@ -331,7 +331,7 @@ public OutputFormatterCallback<Target> createPostFactoStreamCallback(
         public void processOutput(Iterable<Target> partialResult) {
 
           for (Target target : partialResult) {
-            packageNames.add(target.getLabel().getPackageName());
+            packageNames.add(target.getPackage().getPackageIdentifier().toString());
           }
         }
 

src/test/shell/bazel/local_repository_test.sh

@@ -427,6 +427,17 @@ EOF
   expect_log "//external:my_repo"
 }
 
+function test_repository_package_query() {
+  mkdir a b b/b
+  echo "local_repository(name='b', path='b')" > WORKSPACE
+  echo "sh_library(name='a', deps=['@b//b'])" > a/BUILD
+  touch b/WORKSPACE
+  echo "sh_library(name='b')" > b/b/BUILD
+  bazel query --output package "deps(//a)" >& $TEST_log || fail "query failed"
+  expect_log "a"
+  expect_log "@b//b"
+}
+
 function test_warning() {
   local bar=$TEST_TMPDIR/bar
   rm -rf "$bar"