using classpath shrinker plugin to warn about indirect dependency usage

Author: natansil

WORKSPACE

@@ -29,3 +29,7 @@ maven_jar(
   sha1 = "e5b3e2753d0817b622c32aedcb888bcf39e275b4")
 
 
+http_jar(
+    name = "classpath_shrinker",
+    url = "file:///Users/natans/work/classpath-shrinker/plugin/target/scala-2.11/classpath-shrinker_2.11-0.1.1.jar",
+)

scala/scala.bzl

@@ -149,7 +149,7 @@ def _collect_plugin_paths(plugins):
     return paths
 
 
-def _compile(ctx, cjars, dep_srcjars, buildijar):
+def _compile(ctx, cjars, dep_srcjars, buildijar, rjars=[], labels = {}):
     ijar_output_path = ""
     ijar_cmd_path = ""
     if buildijar:
@@ -164,7 +164,11 @@ def _compile(ctx, cjars, dep_srcjars, buildijar):
     plugins = _collect_plugin_paths(ctx.attr.plugins)
     plugin_arg = ",".join(list(plugins))
 
-    compiler_classpath = ":".join([j.path for j in cjars])
+    all_jars = cjars + rjars
+    compiler_classpath = ":".join([j.path for j in all_jars])
+    direct_jars = ":".join([j.path for j in cjars])
+    indirect_jars = ":".join([j.path for j in rjars])
+    indirect_targets = ":".join([labels[j.path] for j in rjars])
 
     scalac_args = """
 Classpath: {cp}
@@ -186,6 +190,9 @@ ResourceSrcs: {resource_src}
 ResourceStripPrefix: {resource_strip_prefix}
 ScalacOpts: {scala_opts}
 SourceJars: {srcjars}
+DirectJars: {direct_jars}
+IndirectJars: {indirect_jars}
+IndirectTargets: {indirect_targets}
 """.format(
         out=ctx.outputs.jar.path,
         manifest=ctx.outputs.manifest.path,
@@ -209,6 +216,9 @@ SourceJars: {srcjars}
           ),
         resource_strip_prefix=ctx.attr.resource_strip_prefix,
         resource_jars=",".join([f.path for f in ctx.files.resource_jars]),
+        direct_jars=direct_jars,
+        indirect_jars=indirect_jars,
+        indirect_targets=indirect_targets
         )
     argfile = ctx.new_file(
       ctx.outputs.jar,
@@ -222,7 +232,7 @@ SourceJars: {srcjars}
     # _jdk added manually since _java doesn't currently setup runfiles
     # _scalac, as a java_binary, should already have it in its runfiles; however,
     # adding does ensure _java not orphaned if _scalac ever was not a java_binary
-    ins = (list(cjars) +
+    ins = (list(all_jars) +
            list(dep_srcjars) +
            list(srcjars) +
            list(sources) +
@@ -256,14 +266,14 @@ SourceJars: {srcjars}
       )
 
 
-def _compile_or_empty(ctx, jars, srcjars, buildijar):
+def _compile_or_empty(ctx, jars, srcjars, buildijar, transitive_jars, jars2labels):
     # We assume that if a srcjar is present, it is not empty
     if len(ctx.files.srcs) + len(srcjars) == 0:
         _build_nosrc_jar(ctx, buildijar)
         #  no need to build ijar when empty
         return struct(ijar=ctx.outputs.jar, class_jar=ctx.outputs.jar)
     else:
-        _compile(ctx, jars, srcjars, buildijar)
+        _compile(ctx, jars, srcjars, buildijar, transitive_jars, jars2labels)
         ijar = None
         if buildijar:
             ijar = ctx.outputs.ijar
@@ -357,18 +367,21 @@ def _collect_jars(targets):
     """Compute the runtime and compile-time dependencies from the given targets"""  # noqa
     compile_jars = depset()
     runtime_jars = depset()
+    jars2labels = {}
     for target in targets:
         if java_common.provider in target:
             java_provider = target[java_common.provider]
             compile_jars += java_provider.compile_jars
             runtime_jars += java_provider.transitive_runtime_jars
+            jars2labels.update(dict([(jar.path, target.label)
+              for jar in (java_provider.compile_jars + java_provider.transitive_runtime_jars)]))
         else:
             # support http_file pointed at a jar. http_jar uses ijar,
             # which breaks scala macros
             compile_jars += target.files
             runtime_jars += target.files
 
-    return struct(compile_jars = compile_jars, transitive_runtime_jars = runtime_jars)
+    return struct(compile_jars = compile_jars, transitive_runtime_jars = runtime_jars, jars2labels=jars2labels)
 
 # Extract very common code out from dependency analysis into single place
 # automatically adds dependency on scala-library and scala-reflect
@@ -377,10 +390,13 @@ def _collect_jars_from_common_ctx(ctx, extra_deps = [], extra_runtime_deps = [])
     # Get jars from deps
     auto_deps = [ctx.attr._scalalib, ctx.attr._scalareflect]
     deps_jars = _collect_jars(ctx.attr.deps + auto_deps + extra_deps)
-    (cjars, transitive_rjars) = (deps_jars.compile_jars, deps_jars.transitive_runtime_jars)
-    transitive_rjars += _collect_jars(
-        ctx.attr.runtime_deps + extra_runtime_deps).transitive_runtime_jars
-    return struct(compile_jars = cjars, transitive_runtime_jars = transitive_rjars)
+    (cjars, transitive_rjars, jars2labels) = (deps_jars.compile_jars, deps_jars.transitive_runtime_jars, deps_jars.jars2labels)
+
+    runtime_dep_jars =  _collect_jars(ctx.attr.runtime_deps + extra_runtime_deps)
+    transitive_rjars += runtime_dep_jars.transitive_runtime_jars
+
+    jars2labels.update(runtime_dep_jars.jars2labels)
+    return struct(compile_jars = cjars, transitive_runtime_jars = transitive_rjars, jars2labels=jars2labels)
 
 def _lib(ctx, non_macro_lib):
     # Build up information from dependency-like attributes
@@ -392,7 +408,7 @@ def _lib(ctx, non_macro_lib):
     (cjars, transitive_rjars) = (jars.compile_jars, jars.transitive_runtime_jars)
 
     write_manifest(ctx)
-    outputs = _compile_or_empty(ctx, cjars, srcjars, non_macro_lib)
+    outputs = _compile_or_empty(ctx, cjars, srcjars, non_macro_lib, transitive_rjars, jars.jars2labels)
 
     transitive_rjars += [ctx.outputs.jar]
 

src/java/io/bazel/rulesscala/scalac/CompileOptions.java

@@ -23,6 +23,9 @@ public class CompileOptions {
   final public Map<String, String> resourceFiles;
   final public String resourceStripPrefix;
   final public String[] resourceJars;
+  final public String[] directJars;
+  final public String[] indirectJars;
+  final public String[] indirectTargets;
 
   public CompileOptions(List<String> args) {
     Map<String, String> argMap = buildArgMap(args);
@@ -54,6 +57,10 @@ public CompileOptions(List<String> args) {
     resourceFiles = getResources(argMap);
     resourceStripPrefix = getOrEmpty(argMap, "ResourceStripPrefix");
     resourceJars = getCommaList(argMap, "ResourceJars");
+
+    directJars = getCommaList(argMap, "DirectJars");
+    indirectJars = getCommaList(argMap, "IndirectJars");
+    indirectTargets = getCommaList(argMap, "IndirectTargets");
   }
 
   private static Map<String, String> getResources(Map<String, String> args) {

src/java/io/bazel/rulesscala/scalac/ScalacProcessor.java

@@ -192,7 +192,10 @@ private static void compileScalaSources(CompileOptions ops, String[] scalaSource
       "-classpath",
       ops.classpath,
       "-d",
-      tmpPath.toString()
+      tmpPath.toString(),
+            "-P:classpath-shrinker:direct-jars:" + String.join(":", ops.directJars),
+            "-P:classpath-shrinker:indirect-jars:" + String.join(":", ops.indirectJars),
+            "-P:classpath-shrinker:indirect-targets:" + String.join(":", ops.indirectTargets),
     };
 
     String[] compilerArgs = GenericWorker.merge(

test_expect_logs/missing_direct_deps/A.scala

@@ -0,0 +1,8 @@
+package test_expect_logs.missing_direct_deps
+
+object A {
+	def foo = {
+		B.foo
+		C.foo
+	}
+}

test_expect_logs/missing_direct_deps/B.scala

@@ -0,0 +1,7 @@
+package test_expect_logs.missing_direct_deps
+
+object B {
+	def foo = {
+		C.foo
+	}
+}

test_expect_logs/missing_direct_deps/BUILD

@@ -0,0 +1,30 @@
+package(default_visibility = ["//visibility:public"])
+load("//scala:scala.bzl", "scala_library", "scala_test")
+
+scala_library(
+    name="transitive_dependency_user",
+    srcs=[
+        "A.scala",
+        ],
+    deps = ["direct_dependency"],
+    plugins = ["@classpath_shrinker//jar"],
+)
+
+scala_library(
+    name="direct_dependency",
+    srcs=[
+        "B.scala",
+        ],
+    deps = ["transitive_dependency"],
+        plugins = ["@classpath_shrinker//jar"],
+
+)
+
+scala_library(
+    name="transitive_dependency",
+    srcs=[
+        "C.scala",
+        ],
+            plugins = ["@classpath_shrinker//jar"],
+
+)

test_expect_logs/missing_direct_deps/C.scala

@@ -0,0 +1,7 @@
+package test_expect_logs.missing_direct_deps
+
+object C {
+	def foo = {
+		println("in C")
+	}
+}

test_run.sh

@@ -71,6 +71,19 @@ test_scala_library_suite() {
   exit 0
 }
 
+test_scala_library_expect_warning_on_missing_direct_deps() {
+  expected_message="target 'transitive_dependency' should be added to deps"
+  command='bazel build test_expect_logs/missing_direct_deps:transitive_dependency_user'
+  output=$($command 2>&1)
+  echo "$output"
+  echo $output | grep "$expected_message"
+  if [ $? -ne 0 ]; then
+    echo "'bazel build test_expect_logs/missing_direct_deps:transitive_dependency_user' should have logged \"$expected_message\"."
+    exit 1
+  fi
+  exit 0
+}
+
 test_scala_junit_test_can_fail() {
   set +e
 
@@ -339,34 +352,35 @@ else
   runner="run_test_ci"
 fi
 
-$runner bazel build test/...
-$runner bazel test test/...
-$runner bazel run test/src/main/scala/scala/test/twitter_scrooge:justscrooges
-$runner bazel run test:JavaBinary
-$runner bazel run test:JavaBinary2
-$runner bazel run test:MixJavaScalaLibBinary
-$runner bazel run test:MixJavaScalaSrcjarLibBinary
-$runner bazel run test:ScalaBinary
-$runner bazel run test:ScalaLibBinary
-$runner test_disappearing_class
-$runner find -L ./bazel-testlogs -iname "*.xml"
-$runner xmllint_test
-$runner test_build_is_identical
-$runner test_transitive_deps
-$runner test_scala_library_suite
-$runner test_repl
-$runner bazel run test:JavaOnlySources
-$runner test_benchmark_jmh
-$runner multiple_junit_suffixes
-$runner multiple_junit_prefixes
-$runner test_scala_junit_test_can_fail
-$runner junit_generates_xml_logs
-$runner scala_library_jar_without_srcs_must_fail_on_mismatching_resource_strip_prefix
-$runner multiple_junit_patterns
-$runner test_junit_test_must_have_prefix_or_suffix
-$runner test_junit_test_errors_when_no_tests_found
-$runner scala_library_jar_without_srcs_must_include_direct_file_resources
-$runner scala_library_jar_without_srcs_must_include_filegroup_resources
-$runner bazel run test/src/main/scala/scala/test/large_classpath:largeClasspath
-$runner scala_test_test_filters
-$runner scala_junit_test_test_filter
+$runner test_scala_library_expect_warning_on_missing_direct_deps
+#$runner bazel build test/...
+#$runner bazel test test/...
+#$runner bazel run test/src/main/scala/scala/test/twitter_scrooge:justscrooges
+#$runner bazel run test:JavaBinary
+#$runner bazel run test:JavaBinary2
+#$runner bazel run test:MixJavaScalaLibBinary
+#$runner bazel run test:MixJavaScalaSrcjarLibBinary
+#$runner bazel run test:ScalaBinary
+#$runner bazel run test:ScalaLibBinary
+#$runner test_disappearing_class
+#$runner find -L ./bazel-testlogs -iname "*.xml"
+#$runner xmllint_test
+#$runner test_build_is_identical
+#$runner test_transitive_deps
+#$runner test_scala_library_suite
+#$runner test_repl
+#$runner bazel run test:JavaOnlySources
+#$runner test_benchmark_jmh
+#$runner multiple_junit_suffixes
+#$runner multiple_junit_prefixes
+#$runner test_scala_junit_test_can_fail
+#$runner junit_generates_xml_logs
+#$runner scala_library_jar_without_srcs_must_fail_on_mismatching_resource_strip_prefix
+#$runner multiple_junit_patterns
+#$runner test_junit_test_must_have_prefix_or_suffix
+#$runner test_junit_test_errors_when_no_tests_found
+#$runner scala_library_jar_without_srcs_must_include_direct_file_resources
+#$runner scala_library_jar_without_srcs_must_include_filegroup_resources
+#$runner bazel run test/src/main/scala/scala/test/large_classpath:largeClasspath
+#$runner scala_test_test_filters
+#$runner scala_junit_test_test_filter