Use java toolchains

The --javabase, and --java_toolchain options are removed in Bazel 5.0.
bazelbuild/bazel#7849

Also removed javacopt as the default java options includes "-g", which
generates all debugging information (source,lines,vars). See
https://cs.opensource.google/bazel/bazel/+/refs/tags/5.0.0:tools/jdk/default_java_toolchain.bzl;l=49

Two jdk11 toolchains are registered (in addition to the runtime
toolchain). *java8_definition and *java11_definition have different
values for source and target version compatibility. These toolchains can
be switched by using different values of --java_language_version.

Bug: 220902606
Test: presubmit passes
Change-Id: I3c59eb277279b40cc3371e3986c9a5980c370e3c

Author: Tom Renn

bazel/bazel.bzl

@@ -136,7 +136,6 @@ def _iml_module_jar_impl(
             deps = java_deps + kotlin_providers,
             javac_opts = java_common.default_javac_opts(java_toolchain = java_toolchain) + ctx.attr.javacopts,
             java_toolchain = java_toolchain,
-            host_javabase = find_java_runtime_toolchain(ctx, ctx.attr._host_javabase),
             sourcepath = sourcepath,
             # TODO(b/216385876) After updating to Bazel 5.0, use enable_compile_jar_action = use_ijar,
         )
@@ -371,7 +370,6 @@ _iml_module_ = rule(
         "data": attr.label_list(allow_files = True),
         "test_data": attr.label_list(allow_files = True),
         "_java_toolchain": attr.label(default = Label("@bazel_tools//tools/jdk:current_java_toolchain")),
-        "_host_javabase": attr.label(default = Label("@bazel_tools//tools/jdk:current_host_java_runtime")),
         "_zipper": attr.label(
             default = Label("@bazel_tools//tools/zip:zipper"),
             cfg = "host",

bazel/common.bazelrc

@@ -47,7 +47,6 @@ build:datasize_aspect --output_groups=+data_size
 
 build --incompatible_strict_action_env # Ensures actions don't pick up env changes
 build --sandbox_tmpfs_path=/tmp
-build --javacopt="-g:source,lines,vars"  # Keep debug info
 # TODO (b/141269926): this generates a warning on windows when building for host,
 # but is required when building for android.
 build --copt=-fvisibility=hidden
@@ -58,11 +57,10 @@ build --define=grpc_no_ares=true
 # finds make in the ndk-build script (see b/72179674).
 build --test_env=SHELL
 
-# Use prebuilt JDK when doing local bazel build/test
-build --host_javabase=//prebuilts/studio/jdk:jdk11_runtime
-build --javabase=//prebuilts/studio/jdk:jdk11_runtime
-build --host_java_toolchain=@bazel_tools//tools/jdk:legacy_toolchain
-build --java_toolchain=@bazel_tools//tools/jdk:legacy_toolchain
+# Bazel will find the matching java toolchain registered in WORKSPACE.
+build --java_language_version=8
+build --java_runtime_version=jdk11
+build --tool_java_runtime_version=jdk11
 
 # Use prebuilt native toolchain
 build --crosstool_top=@native_toolchain//:toolchain

bazel/kotlin.bzl

@@ -133,14 +133,13 @@ def kotlin_test(
     )
 
 # Creates actions to generate the sources jar
-def _sources(ctx, srcs, source_jars, jar, java_toolchain, host_javabase):
+def _sources(ctx, srcs, source_jars, jar, java_toolchain):
     java_common.pack_sources(
         ctx.actions,
         output_source_jar = jar,
         sources = srcs,
         source_jars = source_jars,
         java_toolchain = java_toolchain,
-        host_javabase = host_javabase,
     )
 
 # Creates actions to generate a resources_jar from the given resources.
@@ -297,7 +296,6 @@ def _kotlin_library_impl(ctx):
         jars += [resources_jar]
 
     java_toolchain = find_java_toolchain(ctx, ctx.attr._java_toolchain)
-    host_javabase = find_java_runtime_toolchain(ctx, ctx.attr._host_javabase)
 
     # Java
     if java_srcs or source_jars:
@@ -310,8 +308,7 @@ def _kotlin_library_impl(ctx):
             deps = deps + kotlin_providers,
             javac_opts = java_common.default_javac_opts(java_toolchain = java_toolchain) + ctx.attr.javacopts,
             java_toolchain = java_toolchain,
-            host_javabase = host_javabase,
-            plugins = [plugin[JavaInfo] for plugin in ctx.attr.plugins],
+            plugins = [plugin[JavaPluginInfo] for plugin in ctx.attr.plugins],
             # TODO(b/216385876) After updating to Bazel 5.0, use enable_compile_jar_action = use_ijar,
         )
 
@@ -337,7 +334,7 @@ def _kotlin_library_impl(ctx):
             allow_duplicates = True,
         )
 
-    _sources(ctx, java_srcs + kotlin_srcs, source_jars, ctx.outputs.source_jar, java_toolchain, host_javabase)
+    _sources(ctx, java_srcs + kotlin_srcs, source_jars, ctx.outputs.source_jar, java_toolchain)
 
     java_info = JavaInfo(
         output_jar = ctx.outputs.jar,
@@ -382,11 +379,10 @@ _kotlin_library = rule(
         "kotlin_use_ir": attr.bool(),
         "compress_resources": attr.bool(),
         "plugins": attr.label_list(
-            providers = [JavaInfo],
+            providers = [JavaPluginInfo],
         ),
         "stdlib": attr.label(),
         "_java_toolchain": attr.label(default = Label("@bazel_tools//tools/jdk:current_java_toolchain")),
-        "_host_javabase": attr.label(default = Label("@bazel_tools//tools/jdk:current_host_java_runtime")),
         "_bootclasspath": attr.label(
             # Use JDK 8 because AGP still needs to support it (b/166472930).
             default = Label("//prebuilts/studio/jdk:bootclasspath"),

bazel/toplevel.WORKSPACE

@@ -11,6 +11,9 @@ register_toolchains(
     "@native_toolchain//:cc-toolchain-x64_windows-clang-cl",
     "//tools/base/bazel/toolchains/darwin:python_toolchain",
     "//tools/base/bazel/toolchains/darwin:python_toolchain_10.13",
+    "//prebuilts/studio/jdk:runtime_toolchain_definition",
+    "//prebuilts/studio/jdk:jdk11_toolchain_java8_definition",
+    "//prebuilts/studio/jdk:jdk11_toolchain_java11_definition",
 )
 
 local_repository(