Enable access to file values in repository context

ctx.path now works with labels. When given a label, ctx.path()
will returns the path to the corresponding file if the label
point to a file, or error out if it does not point to file.

Also fix a small case with repository_ctx.symlink that wasn't
creating its directories.

This is needed to enable reading template files to create a
template function (see http://goo.gl/fD4ZsY) for issue #893
(step 4 of http://goo.gl/OZV3o0).

--
MOS_MIGRATED_REVID=115438400

3 files changed, 36 insertions, 2 deletions

diff --git a/src/test/java/com/google/devtools/build/lib/BUILD b/src/test/java/com/google/devtools/build/lib/BUILD
index 2951ca5e3c..7d2a2d0637 100644
--- a/src/test/java/com/google/devtools/build/lib/BUILD
+++ b/src/test/java/com/google/devtools/build/lib/BUILD
@@ -1053,6 +1053,7 @@ java_test(
         "//third_party:guava-testlib",
         "//third_party:jsr305",
         "//third_party:junit4",
+        "//third_party:mockito",
         "//third_party:truth",
     ],
 )
diff --git a/src/test/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkRepositoryContextTest.java b/src/test/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkRepositoryContextTest.java
index 22b185e603..7d7a81444e 100644
--- a/src/test/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkRepositoryContextTest.java
+++ b/src/test/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkRepositoryContextTest.java
@@ -35,11 +35,13 @@ import com.google.devtools.build.lib.syntax.Runtime;
 import com.google.devtools.build.lib.syntax.Type;
 import com.google.devtools.build.lib.testutil.Scratch;
 import com.google.devtools.build.lib.vfs.Path;
+import com.google.devtools.build.skyframe.SkyFunction;
 
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
+import org.mockito.Mockito;
 
 import java.io.IOException;
 import java.io.InputStreamReader;
@@ -87,7 +89,12 @@ public class SkylarkRepositoryContextTest {
             .externalPackageData()
             .createAndAddRepositoryRule(
                 packageBuilder, buildRuleClass(attributes), null, kwargs, ast);
-    context = new SkylarkRepositoryContext(rule, outputDirectory, ImmutableMap.of("FOO", "BAR"));
+    context =
+        new SkylarkRepositoryContext(
+            rule,
+            outputDirectory,
+            Mockito.mock(SkyFunction.Environment.class),
+            ImmutableMap.of("FOO", "BAR"));
   }
 
   protected void setUpContexForRule(String name) throws Exception {
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
index 86a2a485a5..aaca4d0edb 100644
--- 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
@@ -153,7 +153,7 @@ public class SkylarkRepositoryIntegrationTest extends BuildViewTestCase {
     scratch.file(
         "def.bzl",
         "def _impl(ctx):",
-        "  ctx.symlink(ctx.path(ctx.attr.path), ctx.path(''))",
+        "  ctx.symlink(ctx.attr.path, '')",
         "",
         "repo = repository_rule(",
         "    implementation=_impl,",
@@ -169,4 +169,30 @@ public class SkylarkRepositoryIntegrationTest extends BuildViewTestCase {
     Object path = target.getTarget().getAssociatedRule().getAttributeContainer().getAttr("path");
     assertThat(path).isEqualTo("foo");
   }
+
+  @Test
+  public void testSkylarkSymlinkFileFromRepository() throws Exception {
+    scratch.file("/repo2/bar.txt", "filegroup(name='bar', srcs=['foo.txt'], path='foo')");
+    scratch.file("/repo2/BUILD");
+    scratch.file("/repo2/WORKSPACE");
+    scratch.file(
+        "def.bzl",
+        "def _impl(ctx):",
+        "  ctx.symlink(Label('@repo2//:bar.txt'), 'BUILD')",
+        "  ctx.file('foo.txt', 'foo')",
+        "",
+        "repo = repository_rule(",
+        "    implementation=_impl,",
+        "    local=True)");
+    scratch.file(rootDirectory.getRelative("BUILD").getPathString());
+    scratch.overwriteFile(
+        rootDirectory.getRelative("WORKSPACE").getPathString(),
+        "local_repository(name='repo2', path='/repo2')",
+        "load('//:def.bzl', 'repo')",
+        "repo(name='foo')");
+    invalidatePackages();
+    ConfiguredTarget target = getConfiguredTarget("@foo//:bar");
+    Object path = target.getTarget().getAssociatedRule().getAttributeContainer().getAttr("path");
+    assertThat(path).isEqualTo("foo");
+  }
 }