Use a provider for jars2labels (#534)

* Use a provider for jars2labels

* use http to download scala, is safe with a hash

* minor clean ups

* fix tests

scala/jars_to_labels.bzl

@@ -0,0 +1,3 @@
+JarsToLabelsInfo = provider(fields = [
+    "jars_to_labels",  # dict of path of a jar to a label
+])

scala/private/common.bzl

@@ -1,3 +1,7 @@
+load("@io_bazel_rules_scala//scala:jars_to_labels.bzl", "JarsToLabelsInfo")
+
+_empty_jars2labels = JarsToLabelsInfo(jars_to_labels = {})
+
 def write_manifest(ctx):
   main_class = getattr(ctx.attr, "main_class", None)
   write_manifest_file(ctx.actions, ctx.outputs.manifest, main_class)
@@ -42,7 +46,7 @@ def _collect_jars_when_dependency_analyzer_is_off(dep_targets):
   return struct(
       compile_jars = depset(transitive = compile_jars),
       transitive_runtime_jars = depset(transitive = runtime_jars),
-      jars2labels = {},
+      jars2labels = _empty_jars2labels,
       transitive_compile_jars = depset())
 
 def _collect_jars_when_dependency_analyzer_is_on(dep_targets):
@@ -62,6 +66,7 @@ def _collect_jars_when_dependency_analyzer_is_on(dep_targets):
 
       compile_jars.append(current_dep_compile_jars)
       transitive_compile_jars.append(current_dep_transitive_compile_jars)
+
       add_labels_of_jars_to(jars2labels, dep_target,
                             current_dep_transitive_compile_jars.to_list(),
                             current_dep_compile_jars.to_list())
@@ -71,7 +76,7 @@ def _collect_jars_when_dependency_analyzer_is_on(dep_targets):
   return struct(
       compile_jars = depset(transitive = compile_jars),
       transitive_runtime_jars = depset(transitive = runtime_jars),
-      jars2labels = jars2labels,
+      jars2labels = JarsToLabelsInfo(jars_to_labels = jars2labels),
       transitive_compile_jars = depset(transitive = transitive_compile_jars))
 
 # When import mavan_jar's for scala macros we have to use the jar:file requirement
@@ -91,33 +96,23 @@ def filter_not_sources(deps):
 
 def add_labels_of_jars_to(jars2labels, dependency, all_jars, direct_jars):
   for jar in direct_jars:
-    _add_label_of_direct_jar_to(jars2labels, dependency, jar)
+    jars2labels[jar.path] = dependency.label
   for jar in all_jars:
-    _add_label_of_indirect_jar_to(jars2labels, dependency, jar)
-
-def _add_label_of_direct_jar_to(jars2labels, dependency, jar):
-  jars2labels[jar.path] = dependency.label
-
-def _add_label_of_indirect_jar_to(jars2labels, dependency, jar):
-  if _label_already_exists(jars2labels, jar):
-    return
-
-  # skylark exposes only labels of direct dependencies.
-  # to get labels of indirect dependencies we collect them from the providers transitively
-  if _provider_of_dependency_contains_label_of(dependency, jar):
-    jars2labels[jar.path] = dependency.jars_to_labels[jar.path]
+    path = jar.path
+    if path not in jars2labels:
+      # skylark exposes only labels of direct dependencies.
+      # to get labels of indirect dependencies we collect them from the providers transitively
+      label = _provider_of_dependency_label_of(dependency, path)
+      if label == None:
+        label = "Unknown label of file {jar_path} which came from {dependency_label}".format(
+            jar_path = path, dependency_label = dependency.label)
+      jars2labels[path] = label
+
+def _provider_of_dependency_label_of(dependency, path):
+  if JarsToLabelsInfo in dependency:
+    return dependency[JarsToLabelsInfo].jars_to_labels.get(path)
   else:
-    jars2labels[
-        jar.
-        path] = "Unknown label of file {jar_path} which came from {dependency_label}".format(
-            jar_path = jar.path, dependency_label = dependency.label)
-
-def _label_already_exists(jars2labels, jar):
-  return jar.path in jars2labels
-
-def _provider_of_dependency_contains_label_of(dependency, jar):
-  return hasattr(dependency,
-                 "jars_to_labels") and jar.path in dependency.jars_to_labels
+    return None
 
 # TODO this seems to have limited value now that JavaInfo has everything
 def create_java_provider(scalaattr, transitive_compile_time_jars):

scala/private/rule_impls.bzl

@@ -24,6 +24,7 @@ load(
     "not_sources_jar",
     "write_manifest",
 )
+load("@io_bazel_rules_scala//scala:jars_to_labels.bzl", "JarsToLabelsInfo")
 
 _java_extension = ".java"
 _scala_extension = ".scala"
@@ -509,7 +510,7 @@ def _lib(ctx, non_macro_lib):
   write_manifest(ctx)
   outputs = _compile_or_empty(ctx, ctx.outputs.manifest, cjars, srcjars,
                               non_macro_lib, jars.transitive_compile_jars,
-                              jars.jars2labels, [])
+                              jars.jars2labels.jars_to_labels, [])
 
   transitive_rjars = depset(outputs.full_jars, transitive = [transitive_rjars])
 
@@ -543,7 +544,7 @@ def _lib(ctx, non_macro_lib):
   return struct(
       files = depset([ctx.outputs.jar]),  # Here is the default output
       scala = scalaattr,
-      providers = [java_provider],
+      providers = [java_provider, jars.jars2labels],
       runfiles = runfiles,
       jars_to_labels = jars.jars2labels,
     )
@@ -564,7 +565,8 @@ def _scala_binary_common(ctx,
                          implicit_junit_deps_needed_for_java_compilation = []):
   write_manifest(ctx)
   outputs = _compile_or_empty(ctx, ctx.outputs.manifest, cjars, depset(), False,
-                              transitive_compile_time_jars, jars2labels,
+                              transitive_compile_time_jars,
+                              jars2labels.jars_to_labels,
                               implicit_junit_deps_needed_for_java_compilation
                              )  # no need to build an ijar for an executable
   rjars = depset(outputs.full_jars, transitive = [rjars])
@@ -590,11 +592,10 @@ def _scala_binary_common(ctx,
 
   return struct(
       files = depset([ctx.outputs.executable, ctx.outputs.jar]),
-      providers = [java_provider],
+      providers = [java_provider, jars2labels],
       scala = scalaattr,
       transitive_rjars =
       rjars,  #calling rules need this for the classpath in the launcher
-      jars_to_labels = jars2labels,
       runfiles = runfiles)
 
 def scala_binary_impl(ctx):
@@ -683,8 +684,10 @@ def scala_test_impl(ctx):
     transitive_compile_jars = depset(
         transitive = [scalatest_jars, transitive_compile_jars])
     scalatest_jars_list = scalatest_jars.to_list()
-    add_labels_of_jars_to(jars_to_labels, ctx.attr._scalatest,
-                          scalatest_jars_list, scalatest_jars_list)
+    j2l = jars_to_labels.jars_to_labels
+    add_labels_of_jars_to(j2l, ctx.attr._scalatest, scalatest_jars_list,
+                          scalatest_jars_list)
+    jars_to_labels = JarsToLabelsInfo(jars_to_labels = j2l)
 
   args = " ".join([
       "-R \"{path}\"".format(path = ctx.outputs.jar.short_path),

scala/scala_import.bzl

@@ -1,3 +1,5 @@
+load("@io_bazel_rules_scala//scala:jars_to_labels.bzl", "JarsToLabelsInfo")
+
 #intellij part is tested manually, tread lightly when changing there
 #if you change make sure to manually re-import an intellij project and see imports
 #are resolved (not red) and clickable
@@ -20,12 +22,12 @@ def _scala_import_impl(ctx):
   return struct(
       scala = struct(outputs = struct(jars = intellij_metadata),
                     ),
-      jars_to_labels = jars2labels,
       providers = [
           _create_provider(current_jars, transitive_runtime_jars, jars, exports,
                            ctx.attr.neverlink),
           DefaultInfo(files = current_jars,
                      ),
+          JarsToLabelsInfo(jars_to_labels = jars2labels),
       ],
   )
 
@@ -96,15 +98,12 @@ def _collect(deps):
 
 def _collect_labels(deps, jars2labels):
   for dep_target in deps:
+    if JarsToLabelsInfo in dep_target:
+      jars2labels.update(dep_target[JarsToLabelsInfo].jars_to_labels)
+    #scala_library doesn't add labels to the direct dependency itself
     java_provider = dep_target[JavaInfo]
-    _transitively_accumulate_labels(dep_target, java_provider, jars2labels)
-
-def _transitively_accumulate_labels(dep_target, java_provider, jars2labels):
-  if hasattr(dep_target, "jars_to_labels"):
-    jars2labels.update(dep_target.jars_to_labels)
-  #scala_library doesn't add labels to the direct dependency itself
-  for jar in java_provider.compile_jars.to_list():
-    jars2labels[jar.path] = dep_target.label
+    for jar in java_provider.compile_jars.to_list():
+      jars2labels[jar.path] = dep_target.label
 
 def _collect_runtime(runtime_deps):
   jar_deps = []