Initial check-in of skydoc rewrite.

This skydoc rewrite uses an actual skylark interpreter with a faked build API (implementing the actual build API that Bazel uses).

There's a lot left to do here, this is a barebones start.
For example, this does not yet handle:
  - load() statements
  - non-global build API elements (e.g. apple_common)
  - output of any rule information other than attribute names
  - markdown output format

RELNOTES: None.
PiperOrigin-RevId: 202187207

1 files changed, 58 insertions, 0 deletions

diff --git a/src/main/java/com/google/devtools/build/skydoc/rendering/RuleInfo.java b/src/main/java/com/google/devtools/build/skydoc/rendering/RuleInfo.java
new file mode 100644
index 0000000000..0d8a150dfc
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/skydoc/rendering/RuleInfo.java
@@ -0,0 +1,58 @@
+// Copyright 2018 The Bazel Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.devtools.build.skydoc.rendering;
+
+import com.google.common.base.Joiner;
+import com.google.common.base.Strings;
+import com.google.devtools.build.lib.events.Location;
+import java.util.Collection;
+
+/**
+ * Stores information about a skylark rule definition.
+ */
+public class RuleInfo {
+
+  private final Location location;
+  private final String docString;
+  private final Collection<String> attrNames;
+
+  public RuleInfo(Location location, String docString, Collection<String> attrNames) {
+    this.location = location;
+    this.docString = docString;
+    this.attrNames = attrNames;
+  }
+
+  public Location getLocation() {
+    return location;
+  }
+
+  public String getDocString() {
+    return docString;
+  }
+
+  public Collection<String> getAttrNames() {
+    return attrNames;
+  }
+
+  public String getDescription() {
+    StringBuilder stringBuilder = new StringBuilder();
+    if (!Strings.isNullOrEmpty(docString)) {
+      stringBuilder.append(docString);
+      stringBuilder.append("\n");
+    }
+    Joiner.on(",").appendTo(stringBuilder, attrNames);
+    return stringBuilder.toString();
+  }
+}