Turn back on ijars for Scala 3

rules/private/phases/phase_javainfo.bzl

@@ -28,15 +28,6 @@ def phase_javainfo(ctx, g):
     if len(ctx.attr.srcs) == 0 and len(ctx.attr.resources) == 0:
         java_info = java_common.merge([g.classpaths.sdeps, sexports, sruntime_deps])
     else:
-        # TODO: why do ijars break Scala 3?
-        # For some yet unknown reason ijars break Scala 3.
-        # Bazel now handles .tasty files, but the Scala 3 test fails to pass
-        # when this ijar is used as the compile jar. My guess is that the
-        # classfile format changed somehow for Scala 3 and Bazel does not yet
-        # handle that.
-        #
-        # In the meantime, we've added a use_ijar Scala configuration value and
-        # only use ijars for Scala 2 targets.
         compile_jar = ctx.outputs.jar
         if (ctx.attr.scala[_ScalaConfiguration].use_ijar):
             compile_jar = java_common.run_ijar(

rules/scala.bzl

@@ -501,7 +501,7 @@ configure_bootstrap_scala = rule(
             doc = "Scalac options that will always be enabled.",
         ),
         "use_ijar": attr.bool(
-            doc = "Whether to use ijars for this compiler. Scala 3 currently cannot use ijars.",
+            doc = "Whether to use ijars for this compiler.",
             default = True,
         ),
     },
@@ -535,7 +535,7 @@ _configure_zinc_scala = rule(
             default = "warn",
         ),
         "use_ijar": attr.bool(
-            doc = "Whether to use ijars for this compiler. Scala 3 currently cannot use ijars.",
+            doc = "Whether to use ijars for this compiler.",
             default = True,
         ),
         "deps_direct": attr.string(default = "error"),

src/main/scala/BUILD

@@ -96,7 +96,7 @@ configure_bootstrap_scala(
     compiler_classpath = compiler_classpath_3,
     global_scalacopts = shared_global_scalacopts,
     runtime_classpath = runtime_classpath_3,
-    use_ijar = False,
+    use_ijar = True,
     version = scala_3_version,
     visibility = ["//visibility:public"],
 )
@@ -107,7 +107,7 @@ configure_zinc_scala(
     compiler_classpath = compiler_classpath_3,
     global_scalacopts = shared_global_scalacopts,
     runtime_classpath = runtime_classpath_3,
-    use_ijar = False,
+    use_ijar = True,
     version = scala_3_version,
     visibility = ["//visibility:public"],
 )

tests/plugins/macros/test

@@ -1,9 +1,6 @@
 #!/bin/bash -e
 . "$(dirname "$0")"/../../common.sh
 
-# TODO: Re-enable this test once Scala 3 works with ijars
-# macro = True makes you use full jars, and we're doing that
-# all the time now because Scala 3 +ijar breaks. So this always passes
-#bazel build :bad_compile 2>&1 | grep 'You may be missing a `macro = True` attribute.'
+bazel build :bad_compile 2>&1 | grep 'You may be missing a `macro = True` attribute.'
 [ "$(bazel run :test_macro)" = "hello world!" ]
 [ "$(bazel run :test_macro_only)" = $'hello world!\nworld hello!' ]

tests/scala/BUILD

@@ -110,7 +110,7 @@ configure_bootstrap_scala(
     name = "bootstrap_3",
     compiler_classpath = compiler_classpath_3,
     runtime_classpath = runtime_classpath_3,
-    use_ijar = False,
+    use_ijar = True,
     version = scala_3_version,
     visibility = ["//visibility:public"],
 )
@@ -120,7 +120,7 @@ configure_zinc_scala(
     compiler_bridge = "@annex//:org_scala_lang_scala3_sbt_bridge",
     compiler_classpath = compiler_classpath_3,
     runtime_classpath = runtime_classpath_3,
-    use_ijar = False,
+    use_ijar = True,
     version = scala_3_version,
     visibility = ["//visibility:public"],
 )