Introduce SkylarkRepositoryModule

The SkylarkRepositoryModule declare the `repository_rule` function
to Skylark to define new remote repository types (http://goo.gl/OZV3o0).
The work is delagated to the `SkylarkRepositoryFunction` by the
`RepositoryDelegatorFunction`. `SkylarkRepositoryContext` defines the
`ctx` object passed to the `repository_rule` implementation function.

This change also introduce a `SkylarkPath` and the necessary methods
in `SkylarkRepositoryContext` to showcase the creation of a
`local_repository` like repository.

Issue #893: step 3 of the roadmap http://goo.gl/OZV3o0.

--
MOS_MIGRATED_REVID=114895003

5 files changed, 212 insertions, 3 deletions

diff --git a/src/test/java/com/google/devtools/build/lib/BUILD b/src/test/java/com/google/devtools/build/lib/BUILD
index 366fd6bd40..9a9f8caac7 100644
--- a/src/test/java/com/google/devtools/build/lib/BUILD
+++ b/src/test/java/com/google/devtools/build/lib/BUILD
@@ -1028,12 +1028,14 @@ java_test(
 java_test(
     name = "repository_test",
     srcs = glob([
-        "bazel/repository/*.java",
+        "bazel/repository/**/*.java",
     ]),
     tags = ["rules"],
     test_class = "com.google.devtools.build.lib.AllTests",
     deps = [
+        ":analysis_testutil",
         ":foundations_testutil",
+        ":packages_testutil",
         ":test_runner",
         ":testutil",
         "//src/main/java/com/google/devtools/build/lib:bazel-main",
@@ -1042,6 +1044,7 @@ java_test(
         "//src/main/java/com/google/devtools/build/lib:collect",
         "//src/main/java/com/google/devtools/build/lib:inmemoryfs",
         "//src/main/java/com/google/devtools/build/lib:vfs",
+        "//src/main/java/com/google/devtools/build/skyframe",
         "//third_party:guava",
         "//third_party:guava-testlib",
         "//third_party:jsr305",
diff --git a/src/test/java/com/google/devtools/build/lib/analysis/util/AnalysisMock.java b/src/test/java/com/google/devtools/build/lib/analysis/util/AnalysisMock.java
index f75272e4d6..cfa5572506 100644
--- a/src/test/java/com/google/devtools/build/lib/analysis/util/AnalysisMock.java
+++ b/src/test/java/com/google/devtools/build/lib/analysis/util/AnalysisMock.java
@@ -88,7 +88,8 @@ public abstract class AnalysisMock {
 
     return ImmutableMap.of(
         SkyFunctions.REPOSITORY_DIRECTORY,
-        new RepositoryDelegatorFunction(directories, repositoryHandlers, new AtomicBoolean(true)),
+        new RepositoryDelegatorFunction(
+            directories, repositoryHandlers, null, new AtomicBoolean(true)),
         SkyFunctions.REPOSITORY,
         new RepositoryLoaderFunction());
   }
diff --git a/src/test/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkRepositoryIntegrationTest.java b/src/test/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkRepositoryIntegrationTest.java
new file mode 100644
index 0000000000..36746adf28
--- /dev/null
+++ b/src/test/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkRepositoryIntegrationTest.java
@@ -0,0 +1,172 @@
+// Copyright 2016 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.lib.bazel.repository.skylark;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import com.google.common.collect.ImmutableMap;
+import com.google.devtools.build.lib.analysis.BlazeDirectories;
+import com.google.devtools.build.lib.analysis.ConfigurationCollectionFactory;
+import com.google.devtools.build.lib.analysis.ConfiguredRuleClassProvider;
+import com.google.devtools.build.lib.analysis.ConfiguredTarget;
+import com.google.devtools.build.lib.analysis.config.ConfigurationFactory;
+import com.google.devtools.build.lib.analysis.util.AnalysisMock;
+import com.google.devtools.build.lib.analysis.util.BuildViewTestCase;
+import com.google.devtools.build.lib.packages.util.MockCcSupport;
+import com.google.devtools.build.lib.packages.util.MockToolsConfig;
+import com.google.devtools.build.lib.rules.repository.LocalRepositoryFunction;
+import com.google.devtools.build.lib.rules.repository.LocalRepositoryRule;
+import com.google.devtools.build.lib.rules.repository.RepositoryDelegatorFunction;
+import com.google.devtools.build.lib.rules.repository.RepositoryFunction;
+import com.google.devtools.build.lib.rules.repository.RepositoryLoaderFunction;
+import com.google.devtools.build.lib.skyframe.SkyFunctions;
+import com.google.devtools.build.lib.testutil.TestRuleClassProvider;
+import com.google.devtools.build.lib.vfs.Path;
+import com.google.devtools.build.skyframe.SkyFunction;
+import com.google.devtools.build.skyframe.SkyFunctionName;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+import java.io.IOException;
+import java.util.Collection;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+/**
+ * Integration test for skylark repository not as heavyweight than shell integration tests.
+ */
+@RunWith(JUnit4.class)
+public class SkylarkRepositoryIntegrationTest extends BuildViewTestCase {
+
+  // The RuleClassProvider loaded with the SkylarkRepositoryModule
+  private ConfiguredRuleClassProvider ruleProvider = null;
+  // The Analysis mock injected with the SkylarkRepositoryFunction
+  private AnalysisMock analysisMock = null;
+
+  /**
+   * Proxy to the real analysis mock to overwrite {@code #getSkyFunctions(BlazeDirectories)} to
+   * inject the SkylarkRepositoryFunction in the list of SkyFunctions. In Bazel, this function is
+   * injected by the corresponding @{code BlazeModule}.
+   */
+  private static class CustomAnalysisMock extends AnalysisMock {
+
+    private final AnalysisMock proxied;
+
+    CustomAnalysisMock(AnalysisMock proxied) {
+      this.proxied = proxied;
+    }
+
+    @Override
+    public ImmutableMap<SkyFunctionName, SkyFunction> getSkyFunctions(
+        BlazeDirectories directories) {
+      // Add both the local repository and the skylark repository functions
+      RepositoryFunction localRepositoryFunction = new LocalRepositoryFunction();
+      localRepositoryFunction.setDirectories(directories);
+      RepositoryFunction skylarkRepositoryFunction = new SkylarkRepositoryFunction();
+      skylarkRepositoryFunction.setDirectories(directories);
+      ImmutableMap<String, RepositoryFunction> repositoryHandlers =
+          ImmutableMap.of(LocalRepositoryRule.NAME, localRepositoryFunction);
+
+      return ImmutableMap.of(
+          SkyFunctions.REPOSITORY_DIRECTORY,
+          new RepositoryDelegatorFunction(
+              directories, repositoryHandlers, skylarkRepositoryFunction, new AtomicBoolean(true)),
+          SkyFunctions.REPOSITORY,
+          new RepositoryLoaderFunction());
+    }
+
+    @Override
+    public void setupMockClient(MockToolsConfig mockToolsConfig) throws IOException {
+      proxied.setupMockClient(mockToolsConfig);
+    }
+
+    @Override
+    public void setupMockWorkspaceFiles(Path embeddedBinariesRoot) throws IOException {
+      proxied.setupMockWorkspaceFiles(embeddedBinariesRoot);
+    }
+
+    @Override
+    public ConfigurationFactory createConfigurationFactory() {
+      return proxied.createConfigurationFactory();
+    }
+
+    @Override
+    public ConfigurationFactory createFullConfigurationFactory() {
+      return proxied.createFullConfigurationFactory();
+    }
+
+    @Override
+    public ConfigurationCollectionFactory createConfigurationCollectionFactory() {
+      return proxied.createConfigurationCollectionFactory();
+    }
+
+    @Override
+    public Collection<String> getOptionOverrides() {
+      return proxied.getOptionOverrides();
+    }
+
+    @Override
+    public MockCcSupport ccSupport() {
+      return proxied.ccSupport();
+    }
+  }
+
+  @Override
+  protected AnalysisMock getAnalysisMock() {
+    if (analysisMock == null) {
+      analysisMock = new CustomAnalysisMock(super.getAnalysisMock());
+    }
+    return analysisMock;
+  }
+
+  @Override
+  protected ConfiguredRuleClassProvider getRuleClassProvider() {
+    // We inject the repository module in our test rule class provider.
+    if (ruleProvider == null) {
+      ConfiguredRuleClassProvider.Builder builder = new ConfiguredRuleClassProvider.Builder();
+      TestRuleClassProvider.addStandardRules(builder);
+      builder.addSkylarkModule(SkylarkRepositoryModule.class);
+      ruleProvider = builder.build();
+    }
+    return ruleProvider;
+  }
+
+  @Test
+  public void testSkylarkLocalRepository() throws Exception {
+    // A simple test that recreates local_repository with Skylark.
+    scratch.file("/repo2/WORKSPACE");
+    scratch.file("/repo2/bar.txt");
+    scratch.file("/repo2/BUILD", "filegroup(name='bar', srcs=['bar.txt'], path='foo')");
+    scratch.file(
+        "def.bzl",
+        "def _impl(ctx):",
+        "  ctx.symlink(ctx.path(ctx.attr.path), ctx.path(''))",
+        "",
+        "repo = repository_rule(",
+        "    implementation=_impl,",
+        "    local=True,",
+        "    attrs={'path': attr.string(mandatory=True)})");
+    scratch.file(rootDirectory.getRelative("BUILD").getPathString());
+    scratch.overwriteFile(
+        rootDirectory.getRelative("WORKSPACE").getPathString(),
+        "load('//:def.bzl', 'repo')",
+        "repo(name='foo', path='/repo2')");
+    invalidatePackages();
+    ConfiguredTarget target = getConfiguredTarget("@foo//:bar");
+    Object path = target.getTarget().getAssociatedRule().getAttributeContainer().getAttr("path");
+    assertThat(path).isEqualTo("foo");
+  }
+}
diff --git a/src/test/java/com/google/devtools/build/lib/rules/repository/RepositoryFunctionTest.java b/src/test/java/com/google/devtools/build/lib/rules/repository/RepositoryFunctionTest.java
index 84a17b2794..1b7cb5f68e 100644
--- a/src/test/java/com/google/devtools/build/lib/rules/repository/RepositoryFunctionTest.java
+++ b/src/test/java/com/google/devtools/build/lib/rules/repository/RepositoryFunctionTest.java
@@ -53,7 +53,7 @@ public class RepositoryFunctionTest extends BuildViewTestCase {
     }
 
     @Override
-    protected boolean isLocal() {
+    protected boolean isLocal(Rule rule) {
       return false;
     }
 
diff --git a/src/test/shell/bazel/skylark_repository_test.sh b/src/test/shell/bazel/skylark_repository_test.sh
index 7b8d6338ea..c84baf42a6 100755
--- a/src/test/shell/bazel/skylark_repository_test.sh
+++ b/src/test/shell/bazel/skylark_repository_test.sh
@@ -216,6 +216,39 @@ EOF
   expect_log "Tra-la!"
 }
 
+function test_skylark_local_repository() {
+  create_new_workspace
+  repo2=$new_workspace_dir
+
+  cat > BUILD <<'EOF'
+genrule(name='bar', cmd='echo foo | tee $@', outs=['bar.txt'])
+EOF
+
+  cd ${WORKSPACE_DIR}
+  cat > WORKSPACE <<EOF
+load('/test', 'repo')
+repo(name='foo', path='$repo2')
+EOF
+
+  # Our custom repository rule
+  cat >test.bzl <<EOF
+def _impl(ctx):
+  ctx.symlink(ctx.path(ctx.attr.path), ctx.path(""))
+
+repo = repository_rule(
+    implementation=_impl,
+    local=True,
+    attrs={"path": attr.string(mandatory=True)})
+EOF
+  # Need to be in a package
+  cat > BUILD
+
+  bazel build @foo//:bar >& $TEST_log || fail "Failed to build"
+  expect_log "foo"
+  cat bazel-genfiles/external/foo/bar.txt >$TEST_log
+  expect_log "foo"
+}
+
 function tear_down() {
   true
 }