bazel: abstract the build system in static serving.

Provide BazelBuild to stub out the Bazel build.

Tested:

Production use case:
1.) bazel build polygerrit && \
    $(bazel info output_base)/external/local_jdk/bin/java \
     -jar bazel-bin/polygerrit.war daemon -d ../test_site \
     --console-log --show-stack-trace

Development mode use cases:
2.) bazel build polygerrit \
      //polygerrit-ui:polygerrit_components.bower_components.zip &&
    $(bazel info output_base)/external/local_jdk/bin/java \
     -jar bazel-bin/polygerrit.war daemon \
     --polygerrit-dev -d ../gerrit_testsite --console-log --show-stack-trace

checked that updates under polygerrit-ui/app/index.html are served
live.

3.) Run tools/eclipse/project.py, started gwt_daemon launcher,
verified that it worked.

4.) Run tools/eclipse/project.py, started gerit_gwt_debug launcher,
verified that GWT SDM worked.

Change-Id: I9d105e00e953b63c78306e9e37d5152673627727

gerrit-httpd/src/main/java/com/google/gerrit/httpd/raw/BazelBuild.java

@@ -0,0 +1,57 @@
+// Copyright (C) 2016 The Android Open Source Project
+//
+// 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.gerrit.httpd.raw;
+
+import java.io.IOException;
+import java.nio.file.Path;
+
+public class BazelBuild implements BuildSystem {
+  private final Path sourceRoot;
+
+  public BazelBuild(Path sourceRoot) {
+    this.sourceRoot = sourceRoot;
+  }
+
+  @Override
+  public void build(Label l) throws IOException, BuildFailureException {
+    throw new BuildFailureException("not implemented yet.".getBytes());
+  }
+
+  @Override
+  public String buildCommand(Label l) {
+    return "bazel build " + l.toString();
+  }
+
+  @Override
+  public Path targetPath(Label l) {
+    return sourceRoot.resolve("bazel-bin").resolve(l.pkg).resolve(l.name);
+  }
+
+  @Override
+  public Label gwtZipLabel(String agent) {
+    return new Label("gerrit-gwtui", "ui_" + agent + ".zip");
+  }
+
+  @Override
+  public Label polygerritComponents() {
+    return new Label("polygerrit-ui",
+        "polygerrit_components.bower_components.zip");
+  }
+
+  @Override
+  public Label fontZipLabel() {
+    return new Label("polygerrit-ui", "fonts.zip");
+  }
+}

gerrit-httpd/src/main/java/com/google/gerrit/httpd/raw/BowerComponentsDevServlet.java

@@ -15,9 +15,11 @@
 package com.google.gerrit.httpd.raw;
 
 import com.google.common.cache.Cache;
+import com.google.gerrit.httpd.raw.BuildSystem.Label;
 import com.google.gerrit.launcher.GerritLauncher;
 
 import java.io.IOException;
+import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.Objects;
 
@@ -26,24 +28,33 @@ class BowerComponentsDevServlet extends ResourceServlet {
   private static final long serialVersionUID = 1L;
 
   private final Path bowerComponents;
+  private final String buildCommand;
+  private final Path zip;
 
-  BowerComponentsDevServlet(Cache<Path, Resource> cache, Path buckOut)
+  BowerComponentsDevServlet(Cache<Path, Resource> cache,
-      throws IOException {
+      BuildSystem builder) throws IOException {
     super(cache, true);
-    Objects.requireNonNull(buckOut);
 
-    Path zip = buckOut.resolve("gen")
+    Objects.requireNonNull(builder);
-        .resolve("polygerrit-ui")
+    Label pgLabel = builder.polygerritComponents();
-        .resolve("polygerrit_components")
+    buildCommand = builder.buildCommand(pgLabel);
-        .resolve("polygerrit_components.bower_components.zip");
 
-    bowerComponents = GerritLauncher
+    zip = builder.targetPath(pgLabel);
-        .newZipFileSystem(zip)
+    if (zip == null || !Files.exists(zip)) {
-        .getPath("/");
+      bowerComponents = null;
+    } else {
+      bowerComponents = GerritLauncher
+          .newZipFileSystem(zip)
+          .getPath("/");
+    }
   }
 
   @Override
   protected Path getResourcePath(String pathInfo) throws IOException {
+    if (bowerComponents == null) {
+      throw new IOException("No polymer components found: " + zip
+          + ". Run `" + buildCommand + "`?");
+    }
     return bowerComponents.resolve(pathInfo);
   }
 }

gerrit-httpd/src/main/java/com/google/gerrit/httpd/raw/BuckUtils.java

@@ -15,41 +15,39 @@
 package com.google.gerrit.httpd.raw;
 
 import static com.google.common.base.MoreObjects.firstNonNull;
-import static java.nio.charset.StandardCharsets.UTF_8;
 
-import com.google.common.escape.Escaper;
-import com.google.common.html.HtmlEscapers;
 import com.google.common.io.ByteStreams;
 import com.google.gerrit.common.TimeUtil;
-import com.google.gwtexpui.server.CacheHeaders;
 
-import org.eclipse.jgit.util.RawParseUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InterruptedIOException;
-import java.io.PrintWriter;
 import java.nio.file.Files;
 import java.nio.file.NoSuchFileException;
 import java.nio.file.Path;
-import java.nio.file.Paths;
 import java.util.Properties;
 
-import javax.servlet.http.HttpServletResponse;
+class BuckUtils implements BuildSystem {
-
-class BuckUtils {
   private static final Logger log =
       LoggerFactory.getLogger(BuckUtils.class);
+  private final Path sourceRoot;
 
-  static void build(Path root, Path gen, String target)
+  BuckUtils(Path sourceRoot) {
+    this.sourceRoot = sourceRoot;
+  }
+
+  @Override
+  public void build(Label label)
       throws IOException, BuildFailureException {
-    log.info("buck build " + target);
+    log.info("buck build " + label.fullName());
-    Properties properties = loadBuckProperties(gen);
+    Properties properties = loadBuckProperties(
+        sourceRoot.resolve("buck-out/gen/tools/buck/buck.properties"));
     String buck = firstNonNull(properties.getProperty("buck"), "buck");
-    ProcessBuilder proc = new ProcessBuilder(buck, "build", target)
+    ProcessBuilder proc = new ProcessBuilder(buck, "build", label.fullName())
-        .directory(root.toFile())
+        .directory(sourceRoot.toFile())
         .redirectErrorStream(true);
     if (properties.containsKey("PATH")) {
       proc.environment().put("PATH", properties.getProperty("PATH"));
@@ -74,13 +72,14 @@ class BuckUtils {
     }
 
     long time = TimeUtil.nowMs() - start;
-    log.info(String.format("UPDATED    %s in %.3fs", target, time / 1000.0));
+    log.info(String.format("UPDATED    %s in %.3fs", label.fullName(),
+        time / 1000.0));
   }
 
-  private static Properties loadBuckProperties(Path gen) throws IOException {
+  private static Properties loadBuckProperties(Path propPath)
+      throws IOException {
     Properties properties = new Properties();
-    Path p = gen.resolve(Paths.get("tools/buck/buck.properties"));
+    try (InputStream in = Files.newInputStream(propPath)) {
-    try (InputStream in = Files.newInputStream(p)) {
       properties.load(in);
     } catch (NoSuchFileException e) {
       // Ignore; will be run from PATH, with a descriptive error if it fails.
@@ -88,31 +87,38 @@ class BuckUtils {
     return properties;
   }
 
-  static void displayFailure(String rule, byte[] why, HttpServletResponse res)
+  @Override
-      throws IOException {
+  public Path targetPath(Label label) {
-    res.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
+    return sourceRoot.resolve("buck-out")
-    res.setContentType("text/html");
+        .resolve("gen").resolve(label.artifact);
-    res.setCharacterEncoding(UTF_8.name());
-    CacheHeaders.setNotCacheable(res);
-
-    Escaper html = HtmlEscapers.htmlEscaper();
-    try (PrintWriter w = res.getWriter()) {
-      w.write("<html><title>BUILD FAILED</title><body>");
-      w.format("<h1>%s FAILED</h1>", html.escape(rule));
-      w.write("<pre>");
-      w.write(html.escape(RawParseUtils.decode(why)));
-      w.write("</pre>");
-      w.write("</body></html>");
-    }
   }
 
-  static class BuildFailureException extends Exception {
+  @Override
-    private static final long serialVersionUID = 1L;
+  public String buildCommand(Label l) {
+    return "buck build " + l.toString();
+  }
 
-    final byte[] why;
+  @Override
+  public Label gwtZipLabel(String agent) {
+    // TODO(davido): instead of assuming specific Buck's internal
+    // target directory for gwt_binary() artifacts, ask Buck for
+    // the location of user agent permutation GWT zip, e. g.:
+    // $ buck targets --show_output //gerrit-gwtui:ui_safari \
+    //    | awk '{print $2}'
+    String t = "ui_" + agent;
+    return new BuildSystem.Label("gerrit-gwtui", t,
+        String.format("gerrit-gwtui/__gwt_binary_%s__/%s.zip", t, t));
+  }
 
-    BuildFailureException(byte[] why) {
+  @Override
-      this.why = why;
+  public Label polygerritComponents() {
-    }
+    return new Label("polygerrit-ui", "polygerrit_components",
+        "polygerrit-ui/polygerrit_components/" +
+        "polygerrit_components.bower_components.zip");
+  }
+
+  @Override
+  public Label fontZipLabel() {
+      return new Label("polygerrit-ui", "fonts", "polygerrit-ui/fonts/fonts.zip");
   }
 }

gerrit-httpd/src/main/java/com/google/gerrit/httpd/raw/BuildSystem.java

@@ -0,0 +1,114 @@
+// Copyright (C) 2016 The Android Open Source Project
+//
+// 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.gerrit.httpd.raw;
+
+import static java.nio.charset.StandardCharsets.UTF_8;
+
+import com.google.common.escape.Escaper;
+import com.google.common.html.HtmlEscapers;
+import com.google.gwtexpui.server.CacheHeaders;
+
+import org.eclipse.jgit.util.RawParseUtils;
+
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.nio.file.Path;
+
+import javax.servlet.http.HttpServletResponse;
+
+public interface BuildSystem {
+
+  // Represents a label in either buck or bazel.
+  class Label {
+    protected final String pkg;
+    protected final String name;
+
+    // Regrettably, buck confounds rule names and artifact names,
+    // and so we have to lug this along. Non-null only for Buck; in that case,
+    // holds the path relative to buck-out/gen/
+    protected final String artifact;
+
+    public String fullName() {
+      return  "//" + pkg + ":" + name;
+    }
+
+    @Override
+    public String toString() {
+      String s = fullName();
+      if (!name.equals(artifact)) {
+        s += "(" + artifact + ")";
+      }
+      return s;
+    }
+
+    // Label in Buck style.
+    Label(String pkg, String name, String artifact) {
+      this.name = name;
+      this.pkg = pkg;
+      this.artifact = artifact;
+    }
+
+    // Label in Bazel style.
+    Label(String pkg, String name) {
+      this(pkg, name, name);
+    }
+  }
+
+  class BuildFailureException extends Exception {
+    private static final long serialVersionUID = 1L;
+
+    final byte[] why;
+
+    BuildFailureException(byte[] why) {
+      this.why = why;
+    }
+
+    public void display(String rule, HttpServletResponse res)
+        throws IOException {
+      res.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
+      res.setContentType("text/html");
+      res.setCharacterEncoding(UTF_8.name());
+      CacheHeaders.setNotCacheable(res);
+
+      Escaper html = HtmlEscapers.htmlEscaper();
+      try (PrintWriter w = res.getWriter()) {
+        w.write("<html><title>BUILD FAILED</title><body>");
+        w.format("<h1>%s FAILED</h1>", html.escape(rule));
+        w.write("<pre>");
+        w.write(html.escape(RawParseUtils.decode(why)));
+        w.write("</pre>");
+        w.write("</body></html>");
+      }
+    }
+  }
+
+  /** returns the command to build given target */
+  String buildCommand(Label l);
+
+  /** builds the given label. */
+  void build(Label l) throws IOException, BuildFailureException;
+
+  /** returns the root relative path to the artifact for the given label */
+  Path targetPath(Label l);
+
+  /** Label for the agent specific GWT zip. */
+  Label gwtZipLabel(String agent);
+
+  /** Label for the polygerrit component zip. */
+  Label polygerritComponents();
+
+  /** Label for the fonts zip file. */
+  Label fontZipLabel();
+}

gerrit-httpd/src/main/java/com/google/gerrit/httpd/raw/FontsDevServlet.java

@@ -27,18 +27,15 @@ class FontsDevServlet extends ResourceServlet {
 
   private final Path fonts;
 
-  FontsDevServlet(Cache<Path, Resource> cache, Path buckOut)
+  FontsDevServlet(Cache<Path, Resource> cache, BuildSystem builder)
       throws IOException {
     super(cache, true);
-    Objects.requireNonNull(buckOut);
+    Objects.requireNonNull(builder);
 
-    Path zip = buckOut.resolve("gen")
+    Path zip = builder.targetPath(builder.fontZipLabel());
-        .resolve("polygerrit-ui")
+    Objects.requireNonNull(zip);
-        .resolve("fonts")
+
-        .resolve("fonts.zip");
+    fonts = GerritLauncher.newZipFileSystem(zip).getPath("/");
-    fonts = GerritLauncher
-        .newZipFileSystem(zip)
-        .getPath("/");
   }
 
   @Override

gerrit-httpd/src/main/java/com/google/gerrit/httpd/raw/RecompileGwtUiFilter.java

@@ -14,7 +14,7 @@
 
 package com.google.gerrit.httpd.raw;
 
-import com.google.gerrit.httpd.raw.BuckUtils.BuildFailureException;
+import com.google.gerrit.httpd.raw.BuildSystem.Label;
 import com.google.gwtexpui.linker.server.UserAgentRule;
 
 import java.io.File;
@@ -43,48 +43,40 @@ class RecompileGwtUiFilter implements Filter {
   private final UserAgentRule rule = new UserAgentRule();
   private final Set<String> uaInitialized = new HashSet<>();
   private final Path unpackedWar;
-  private final Path gen;
+  private final BuildSystem builder;
-  private final Path root;
 
-  private String lastTarget;
+  private String lastAgent;
   private long lastTime;
 
-  RecompileGwtUiFilter(Path buckOut, Path unpackedWar) {
+  RecompileGwtUiFilter(BuildSystem builder, Path unpackedWar) {
+    this.builder = builder;
     this.unpackedWar = unpackedWar;
-    gen = buckOut.resolve("gen");
-    root = buckOut.getParent();
   }
 
   @Override
   public void doFilter(ServletRequest request, ServletResponse res,
       FilterChain chain) throws IOException, ServletException {
-    String pkg = "gerrit-gwtui";
+    String agent = rule.select((HttpServletRequest) request);
-    String target = "ui_" + rule.select((HttpServletRequest) request);
+    if (unpackedWar != null
-    if (gwtuiRecompile || !uaInitialized.contains(target)) {
+        && (gwtuiRecompile || !uaInitialized.contains(agent))) {
-      String rule = "//" + pkg + ":" + target;
+      Label label = builder.gwtZipLabel(agent);
-      // TODO(davido): instead of assuming specific Buck's internal
+      File zip = builder.targetPath(label).toFile();
-      // target directory for gwt_binary() artifacts, ask Buck for
-      // the location of user agent permutation GWT zip, e. g.:
-      // $ buck targets --show_output //gerrit-gwtui:ui_safari \
-      //    | awk '{print $2}'
-      String child = String.format("%s/__gwt_binary_%s__", pkg, target);
-      File zip = gen.resolve(child).resolve(target + ".zip").toFile();
 
       synchronized (this) {
         try {
-          BuckUtils.build(root, gen, rule);
+          builder.build(label);
-        } catch (BuildFailureException e) {
+        } catch (BuildSystem.BuildFailureException e) {
-          BuckUtils.displayFailure(rule, e.why, (HttpServletResponse) res);
+          e.display(label.toString(), (HttpServletResponse) res);
           return;
         }
 
-        if (!target.equals(lastTarget) || lastTime != zip.lastModified()) {
+        if (!agent.equals(lastAgent) || lastTime != zip.lastModified()) {
-          lastTarget = target;
+          lastAgent = agent;
           lastTime = zip.lastModified();
           unpack(zip, unpackedWar.toFile());
         }
       }
-      uaInitialized.add(target);
+      uaInitialized.add(agent);
     }
     chain.doFilter(request, res);
   }

gerrit-httpd/src/main/java/com/google/gerrit/httpd/raw/StaticModule.java

@@ -221,8 +221,7 @@ public class StaticModule extends ServletModule {
       if (p.unpackedWar != null) {
         return p.unpackedWar.resolve(name);
       }
-      return p.buckOut.resolveSibling("gerrit-war").resolve("src")
+      return p.sourceRoot.resolve("gerrit-war/src/main/webapp/" + name);
-          .resolve("main").resolve("webapp").resolve(name);
     }
   }
 
@@ -233,7 +232,7 @@ public class StaticModule extends ServletModule {
           .with(Key.get(HttpServlet.class, Names.named(GWT_UI_SERVLET)));
       Paths p = getPaths();
       if (p.isDev()) {
-        filter("/").through(new RecompileGwtUiFilter(p.buckOut, p.unpackedWar));
+        filter("/").through(new RecompileGwtUiFilter(p.builder, p.unpackedWar));
       }
     }
 
@@ -286,7 +285,7 @@ public class StaticModule extends ServletModule {
     BowerComponentsDevServlet getBowerComponentsServlet(
         @Named(CACHE) Cache<Path, Resource> cache) throws IOException {
       return getPaths().isDev()
-          ? new BowerComponentsDevServlet(cache, getPaths().buckOut)
+          ? new BowerComponentsDevServlet(cache, getPaths().builder)
           : null;
     }
 
@@ -295,19 +294,19 @@ public class StaticModule extends ServletModule {
     FontsDevServlet getFontsServlet(
         @Named(CACHE) Cache<Path, Resource> cache) throws IOException {
       return getPaths().isDev()
-          ? new FontsDevServlet(cache, getPaths().buckOut)
+          ? new FontsDevServlet(cache, getPaths().builder)
           : null;
     }
 
     private Path polyGerritBasePath() {
       Paths p = getPaths();
       if (options.forcePolyGerritDev()) {
-        checkArgument(p.buckOut != null,
+        checkArgument(p.sourceRoot != null,
-            "no buck-out directory found for PolyGerrit developer mode");
+            "no source root directory found for PolyGerrit developer mode");
       }
 
       if (p.isDev()) {
-        return p.buckOut.getParent().resolve("polygerrit-ui").resolve("app");
+        return p.sourceRoot.resolve("polygerrit-ui").resolve("app");
       }
 
       return p.warFs != null
@@ -318,7 +317,8 @@ public class StaticModule extends ServletModule {
 
   private static class Paths {
     private final FileSystem warFs;
-    private final Path buckOut;
+    private final BuildSystem builder;
+    private final Path sourceRoot;
     private final Path unpackedWar;
     private final boolean development;
 
@@ -338,28 +338,42 @@ public class StaticModule extends ServletModule {
               .getParentFile()
               .getParentFile()
               .toURI());
-          buckOut = null;
+          sourceRoot = null;
           development = false;
+          builder = null;
           return;
         }
         warFs = getDistributionArchive(launcherLoadedFrom);
         if (warFs == null) {
-          buckOut = getDeveloperBuckOut();
           unpackedWar = makeWarTempDir();
           development = true;
         } else if (options.forcePolyGerritDev()) {
-          buckOut = getDeveloperBuckOut();
           unpackedWar = null;
           development = true;
         } else {
-          buckOut = null;
           unpackedWar = null;
           development = false;
+          sourceRoot = null;
+          builder = null;
+          return;
         }
       } catch (IOException e) {
         throw new ProvisionException(
             "Error initializing static content paths", e);
       }
+
+      sourceRoot = getSourseRootOrNull();
+      builder = GerritLauncher.isBazel()
+          ? new BazelBuild(sourceRoot)
+          : new BuckUtils(sourceRoot);
+    }
+
+    private static Path getSourseRootOrNull() {
+      try {
+        return GerritLauncher.resolveInSourceRoot(".");
+      } catch (FileNotFoundException e) {
+        return null;
+      }
     }
 
     private FileSystem getDistributionArchive(File war) throws IOException {
@@ -390,14 +404,6 @@ public class StaticModule extends ServletModule {
       return development;
     }
 
-    private Path getDeveloperBuckOut() {
-      try {
-        return GerritLauncher.getDeveloperBuckOut();
-      } catch (FileNotFoundException e) {
-        return null;
-      }
-    }
-
     private Path makeWarTempDir() {
       // Obtain our local temporary directory, but it comes back as a file
       // so we have to switch it to be a directory post creation.

gerrit-launcher/BUILD

@@ -3,5 +3,17 @@
 java_library(
   name = 'launcher',
   srcs = ['src/main/java/com/google/gerrit/launcher/GerritLauncher.java'],
+  resources = [':workspace-root.txt'],
+  visibility = ['//visibility:public'],
+)
+
+# The root of the workspace is non-hermetic, but we need it for
+# on-the-fly GWT recompiles and PolyGerrit updates.
+genrule(
+  name = 'gen_root',
+  stamp = 1,
+  cmd = ("cat bazel-out/stable-status.txt | " +
+    "grep STABLE_WORKSPACE_ROOT | cut -d ' ' -f 2 > $@"),
+  outs = ['workspace-root.txt'],
   visibility = ['//visibility:public'],
 )

gerrit-launcher/src/main/java/com/google/gerrit/launcher/GerritLauncher.java

@@ -16,6 +16,7 @@ package com.google.gerrit.launcher;
 
 import static java.util.concurrent.TimeUnit.DAYS;
 import static java.util.concurrent.TimeUnit.MILLISECONDS;
+import static java.nio.charset.StandardCharsets.UTF_8;
 
 import java.io.File;
 import java.io.FileNotFoundException;
@@ -42,6 +43,7 @@ import java.util.Enumeration;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Scanner;
 import java.util.SortedMap;
 import java.util.TreeMap;
 import java.util.jar.Attributes;
@@ -622,20 +624,47 @@ public final class GerritLauncher {
     return resolveInSourceRoot("eclipse-out");
   }
 
-  /**
+  static String SOURCE_ROOT_RESOURCE = "/gerrit-launcher/workspace-root.txt";
-   * Locate the path of the {@code buck-out} directory in a source tree.
+
-   *
+  /** returns whether we're running out of a bazel build. */
-   * @return local path of the {@code buck-out} directory in a source tree.
+  public static boolean isBazel() {
-   * @throws FileNotFoundException if the directory cannot be found.
+    Class<GerritLauncher> self = GerritLauncher.class;
-   */
+    URL rootURL = self.getResource(SOURCE_ROOT_RESOURCE);
-  public static Path getDeveloperBuckOut() throws FileNotFoundException {
+    return rootURL != null;
-    return resolveInSourceRoot("buck-out");
   }
 
-  private static Path resolveInSourceRoot(String name)
+  /**
+   * Locate a path in the source tree.
+   *
+   * @return local path of the {@code name} directory in a source tree.
+   * @throws FileNotFoundException if the directory cannot be found.
+   */
+  public static Path resolveInSourceRoot(String name)
       throws FileNotFoundException {
+
     // Find ourselves in the classpath, as a loose class file or jar.
     Class<GerritLauncher> self = GerritLauncher.class;
+
+    // If the build system provides us with a source root, use that.
+    try (InputStream stream = self.getResourceAsStream(SOURCE_ROOT_RESOURCE)) {
+      System.err.println("URL: " + stream);
+      if (stream != null) {
+        try (Scanner scan =
+            new Scanner(stream, UTF_8.name()).useDelimiter("\n")) {
+          if (scan.hasNext()) {
+            Path p = Paths.get(scan.next());
+            if (!Files.exists(p)) {
+              throw new FileNotFoundException(
+                  "source root not found: " + p);
+            }
+            return p;
+          }
+        }
+      }
+    } catch (IOException e) {
+      // not Bazel, then.
+    }
+
     URL u = self.getResource(self.getSimpleName() + ".class");
     if (u == null) {
       throw new FileNotFoundException("Cannot find class " + self.getName());
@@ -674,7 +703,7 @@ public final class GerritLauncher {
 
   private static ClassLoader useDevClasspath()
       throws MalformedURLException, FileNotFoundException {
-    Path out = getDeveloperEclipseOut();
+    Path out = resolveInSourceRoot("eclipse-out");
     List<URL> dirs = new ArrayList<>();
     dirs.add(out.resolve("classes").toUri().toURL());
     ClassLoader cl = GerritLauncher.class.getClassLoader();

polygerrit-ui/BUILD

@@ -6,7 +6,7 @@ load("//tools/bzl:js.bzl", "bower_component_bundle")
 load('//tools/bzl:genrule2.bzl', 'genrule2')
 
 bower_component_bundle(
-  name = "polygerrit_components",
+  name = "polygerrit_components.bower_components",
   deps = [
     '//lib/js:es6-promise',
     '//lib/js:fetch',

polygerrit-ui/app/BUILD

@@ -18,7 +18,7 @@ vulcanize(
     'test/**',
     '**/*_test.html',
     ]),
-  deps = [ "//polygerrit-ui:polygerrit_components"],
+  deps = [ "//polygerrit-ui:polygerrit_components.bower_components"],
 )
 
 filegroup(
@@ -65,7 +65,7 @@ bower_component_bundle(
   name = 'test_components',
   testonly = 1,
   deps = [
-    '//polygerrit-ui:polygerrit_components',
+    '//polygerrit-ui:polygerrit_components.bower_components',
     '//lib/js:iron-test-helpers',
     '//lib/js:test-fixture',
     '//lib/js:web-component-tester',

tools/workspace-status.sh

@@ -19,3 +19,4 @@ for p in plugins/* ; do
   test -d "$p" || continue
   echo STABLE_BUILD_$(echo $(basename $p)_LABEL|tr [a-z] [A-Z]) $(rev $p)
 done
+echo "STABLE_WORKSPACE_ROOT ${PWD}"