Remove uses of java_toolchain_alias

This seems necessary so that we can start using C++ toolchain resolution.

Without it, rules that are using both C++ and Java toolchain can resolve to a second platform (when there is no crosscompiler available on the first platform) and then JDK binaries for the first platform get executed on the second one.

It's only necessary to use the toolchain directly on rules that also have other toolchains, like java_binary.

However on rules, where only JDK toolchain is needed like java_library, the whole mechanism seems to work because a Java toolchain is always available on the first platform. If that wasn't the case - toolchain resolution in java_library would still select first platform due to the use of alias (and the alias would select second execution platform).

(1 execution platform is matched to each target, based on the toolchains required by the rule)

PiperOrigin-RevId: 472313976
Change-Id: I1905c25e5caa6fb5269f1a9b9ee12bf1b9c58ba9

src/main/java/com/google/devtools/build/lib/rules/java/BUILD

@@ -149,6 +149,7 @@ java_library(
         "//src/main/java/com/google/devtools/build/lib/analysis:config/fragment",
         "//src/main/java/com/google/devtools/build/lib/analysis:config/fragment_options",
         "//src/main/java/com/google/devtools/build/lib/analysis:config/invalid_configuration_exception",
+        "//src/main/java/com/google/devtools/build/lib/analysis:config/toolchain_type_requirement",
         "//src/main/java/com/google/devtools/build/lib/analysis:file_provider",
         "//src/main/java/com/google/devtools/build/lib/analysis:package_specification_provider",
         "//src/main/java/com/google/devtools/build/lib/analysis:platform_options",

src/main/java/com/google/devtools/build/lib/rules/java/JavaRuleClasses.java

@@ -17,9 +17,11 @@
 import static com.google.devtools.build.lib.packages.Attribute.attr;
 import static com.google.devtools.build.lib.packages.BuildType.LABEL;
 
+import com.google.common.annotations.VisibleForTesting;
 import com.google.common.collect.ImmutableList;
 import com.google.devtools.build.lib.analysis.RuleDefinition;
 import com.google.devtools.build.lib.analysis.RuleDefinitionEnvironment;
+import com.google.devtools.build.lib.analysis.config.ToolchainTypeRequirement;
 import com.google.devtools.build.lib.analysis.platform.ToolchainInfo;
 import com.google.devtools.build.lib.packages.RuleClass;
 import com.google.devtools.build.lib.packages.RuleClass.Builder.RuleClassType;
@@ -28,8 +30,28 @@
 /** Common rule class definitions for Java rules. */
 public class JavaRuleClasses {
 
-  public static final String JAVA_TOOLCHAIN_ATTRIBUTE_NAME = "$java_toolchain";
-  public static final String JAVA_RUNTIME_ATTRIBUTE_NAME = "$jvm";
+  private static final String JAVA_TOOLCHAIN_ATTRIBUTE_NAME = "$java_toolchain";
+  @VisibleForTesting public static final String JAVA_RUNTIME_ATTRIBUTE_NAME = "$jvm";
+
+  public static final String JAVA_TOOLCHAIN_TYPE_ATTRIBUTE_NAME = "$java_toolchain_type";
+  public static final String JAVA_RUNTIME_TOOLCHAIN_TYPE_ATTRIBUTE_NAME =
+      "$java_runtime_toolchain_type";
+  private static final String TOOLCHAIN_TYPE_LABEL = "//tools/jdk:toolchain_type";
+  private static final String RUNTIME_TOOLCHAIN_TYPE_LABEL = "//tools/jdk:runtime_toolchain_type";
+
+  public static ToolchainTypeRequirement javaToolchainTypeRequirement(
+      RuleDefinitionEnvironment env) {
+    return ToolchainTypeRequirement.builder(env.getToolsLabel(TOOLCHAIN_TYPE_LABEL))
+        .mandatory(true)
+        .build();
+  }
+
+  public static ToolchainTypeRequirement javaRuntimeToolchainTypeRequirement(
+      RuleDefinitionEnvironment env) {
+    return ToolchainTypeRequirement.builder(env.getToolsLabel(RUNTIME_TOOLCHAIN_TYPE_LABEL))
+        .mandatory(true)
+        .build();
+  }
 
   /** Common attributes for rules that depend on ijar. */
   public static final class IjarBaseRule implements RuleDefinition {
@@ -53,7 +75,11 @@ public static final class JavaToolchainBaseRule implements RuleDefinition {
     @Override
     public RuleClass build(RuleClass.Builder builder, RuleDefinitionEnvironment env) {
       return builder
+          .addToolchainTypes(javaToolchainTypeRequirement(env))
           .add(
+              attr(JAVA_TOOLCHAIN_TYPE_ATTRIBUTE_NAME, LABEL)
+                  .value(javaToolchainTypeRequirement(env).toolchainType()))
+          .add( // TODO(b/245144242): Used by IDE integration, remove when toolchains are used
               attr(JAVA_TOOLCHAIN_ATTRIBUTE_NAME, LABEL)
                   .useOutputLicenses()
                   .mandatoryProviders(ToolchainInfo.PROVIDER.id())
@@ -75,11 +101,10 @@ public static final class JavaRuntimeBaseRule implements RuleDefinition {
     @Override
     public RuleClass build(RuleClass.Builder builder, RuleDefinitionEnvironment env) {
       return builder
+          .addToolchainTypes(javaRuntimeToolchainTypeRequirement(env))
           .add(
-              attr(JAVA_RUNTIME_ATTRIBUTE_NAME, LABEL)
-                  .value(JavaSemantics.jvmAttribute(env))
-                  .mandatoryProviders(ToolchainInfo.PROVIDER.id())
-                  .useOutputLicenses())
+              attr(JAVA_RUNTIME_TOOLCHAIN_TYPE_ATTRIBUTE_NAME, LABEL)
+                  .value(javaRuntimeToolchainTypeRequirement(env).toolchainType()))
           .build();
     }
 

src/main/java/com/google/devtools/build/lib/rules/java/JavaRuntimeInfo.java

@@ -14,7 +14,7 @@
 
 package com.google.devtools.build.lib.rules.java;
 
-import static com.google.devtools.build.lib.rules.java.JavaRuleClasses.JAVA_RUNTIME_ATTRIBUTE_NAME;
+import static com.google.devtools.build.lib.packages.BuildType.LABEL;
 
 import com.google.common.collect.ImmutableList;
 import com.google.devtools.build.lib.actions.Artifact;
@@ -25,7 +25,6 @@
 import com.google.devtools.build.lib.collect.nestedset.NestedSet;
 import com.google.devtools.build.lib.collect.nestedset.NestedSetBuilder;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
-import com.google.devtools.build.lib.packages.BuildType;
 import com.google.devtools.build.lib.packages.BuiltinProvider;
 import com.google.devtools.build.lib.packages.NativeInfo;
 import com.google.devtools.build.lib.rules.cpp.CcInfo;
@@ -76,12 +75,19 @@ public static JavaRuntimeInfo forHost(RuleContext ruleContext) {
   }
 
   public static JavaRuntimeInfo from(RuleContext ruleContext) {
-    return from(ruleContext, JAVA_RUNTIME_ATTRIBUTE_NAME);
+    ToolchainInfo toolchainInfo =
+        ruleContext
+            .getToolchainContext()
+            .forToolchainType(
+                ruleContext
+                    .getPrerequisite(JavaRuleClasses.JAVA_RUNTIME_TOOLCHAIN_TYPE_ATTRIBUTE_NAME)
+                    .getLabel());
+    return from(ruleContext, toolchainInfo);
   }
 
   @Nullable
   public static JavaRuntimeInfo from(RuleContext ruleContext, String attributeName) {
-    if (!ruleContext.attributes().has(attributeName, BuildType.LABEL)) {
+    if (!ruleContext.attributes().has(attributeName, LABEL)) {
       return null;
     }
     TransitiveInfoCollection prerequisite = ruleContext.getPrerequisite(attributeName);
@@ -90,6 +96,11 @@ public static JavaRuntimeInfo from(RuleContext ruleContext, String attributeName
     }
 
     ToolchainInfo toolchainInfo = prerequisite.get(ToolchainInfo.PROVIDER);
+    return from(ruleContext, toolchainInfo);
+  }
+
+  @Nullable
+  private static JavaRuntimeInfo from(RuleContext ruleContext, ToolchainInfo toolchainInfo) {
     if (toolchainInfo != null) {
       try {
         JavaRuntimeInfo result = (JavaRuntimeInfo) toolchainInfo.getValue("java_runtime");

src/main/java/com/google/devtools/build/lib/rules/java/JavaSemantics.java

@@ -109,16 +109,6 @@ static Label javaToolchainAttribute(RuleDefinitionEnvironment environment) {
   String DIRECT_SOURCE_JARS_OUTPUT_GROUP =
       OutputGroupInfo.HIDDEN_OUTPUT_GROUP_PREFIX + "direct_source_jars";
 
-  /** Implementation for the :jvm attribute. */
-  static Label jvmAttribute(RuleDefinitionEnvironment env) {
-    return env.getToolsLabel("//tools/jdk:current_java_runtime");
-  }
-
-  /** Implementation for the :host_jdk attribute. */
-  static Label hostJdkAttribute(RuleDefinitionEnvironment env) {
-    return env.getToolsLabel("//tools/jdk:current_host_java_runtime");
-  }
-
   /**
    * Implementation for the :java_launcher attribute. Note that the Java launcher is disabled by
    * default, so it returns null for the configuration-independent default value.

src/main/java/com/google/devtools/build/lib/rules/java/JavaToolchainProvider.java

@@ -17,6 +17,7 @@
 import static com.google.devtools.build.lib.rules.java.JavaStarlarkCommon.checkPrivateAccess;
 
 import com.google.auto.value.AutoValue;
+import com.google.common.annotations.VisibleForTesting;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableListMultimap;
 import com.google.common.collect.ImmutableSet;
@@ -26,7 +27,6 @@
 import com.google.devtools.build.lib.analysis.ProviderCollection;
 import com.google.devtools.build.lib.analysis.RuleContext;
 import com.google.devtools.build.lib.analysis.RuleErrorConsumer;
-import com.google.devtools.build.lib.analysis.TransitiveInfoCollection;
 import com.google.devtools.build.lib.analysis.platform.ToolchainInfo;
 import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.collect.nestedset.Depset;
@@ -55,19 +55,25 @@ public final class JavaToolchainProvider extends NativeInfo
 
   /** Returns the Java Toolchain associated with the rule being analyzed or {@code null}. */
   public static JavaToolchainProvider from(RuleContext ruleContext) {
-    TransitiveInfoCollection prerequisite =
-        ruleContext.getPrerequisite(JavaRuleClasses.JAVA_TOOLCHAIN_ATTRIBUTE_NAME);
-    return from(prerequisite, ruleContext);
+    ToolchainInfo toolchainInfo =
+        ruleContext
+            .getToolchainContext()
+            .forToolchainType(
+                ruleContext
+                    .getPrerequisite(JavaRuleClasses.JAVA_TOOLCHAIN_TYPE_ATTRIBUTE_NAME)
+                    .getLabel());
+    return from(toolchainInfo, ruleContext);
   }
 
+  @VisibleForTesting
   public static JavaToolchainProvider from(ProviderCollection collection) {
-    return from(collection, null);
+    ToolchainInfo toolchainInfo = collection.get(ToolchainInfo.PROVIDER);
+    return from(toolchainInfo, null);
   }
 
   @Nullable
   private static JavaToolchainProvider from(
-      ProviderCollection collection, @Nullable RuleErrorConsumer errorConsumer) {
-    ToolchainInfo toolchainInfo = collection.get(ToolchainInfo.PROVIDER);
+      ToolchainInfo toolchainInfo, @Nullable RuleErrorConsumer errorConsumer) {
     if (toolchainInfo != null) {
       try {
         JavaToolchainProvider provider = (JavaToolchainProvider) toolchainInfo.getValue("java");

src/main/java/com/google/devtools/build/lib/rules/objc/BUILD

@@ -29,6 +29,7 @@ java_library(
         "//src/main/java/com/google/devtools/build/lib/analysis:config/execution_transition_factory",
         "//src/main/java/com/google/devtools/build/lib/analysis:config/fragment",
         "//src/main/java/com/google/devtools/build/lib/analysis:config/fragment_options",
+        "//src/main/java/com/google/devtools/build/lib/analysis:config/toolchain_type_requirement",
         "//src/main/java/com/google/devtools/build/lib/analysis:config/transitions/patch_transition",
         "//src/main/java/com/google/devtools/build/lib/analysis:config/transitions/split_transition",
         "//src/main/java/com/google/devtools/build/lib/analysis:config/transitions/starlark_exposed_rule_transition_factory",
@@ -48,7 +49,6 @@ java_library(
         "//src/main/java/com/google/devtools/build/lib/events",
         "//src/main/java/com/google/devtools/build/lib/packages",
         "//src/main/java/com/google/devtools/build/lib/rules/apple",
-        "//src/main/java/com/google/devtools/build/lib/rules/config",
         "//src/main/java/com/google/devtools/build/lib/rules/cpp",
         "//src/main/java/com/google/devtools/build/lib/rules/java:java-compilation",
         "//src/main/java/com/google/devtools/build/lib/rules/proto",

src/main/java/com/google/devtools/build/lib/rules/objc/J2ObjcAspect.java

@@ -17,7 +17,6 @@
 import static com.google.common.base.Preconditions.checkNotNull;
 import static com.google.devtools.build.lib.packages.Attribute.attr;
 import static com.google.devtools.build.lib.packages.BuildType.LABEL;
-import static com.google.devtools.build.lib.rules.java.JavaRuleClasses.JAVA_TOOLCHAIN_ATTRIBUTE_NAME;
 import static java.nio.charset.StandardCharsets.ISO_8859_1;
 import static java.util.stream.Collectors.toList;
 
@@ -39,7 +38,7 @@
 import com.google.devtools.build.lib.analysis.actions.SpawnAction;
 import com.google.devtools.build.lib.analysis.config.ConfigAwareAspectBuilder;
 import com.google.devtools.build.lib.analysis.config.ExecutionTransitionFactory;
-import com.google.devtools.build.lib.analysis.platform.ToolchainInfo;
+import com.google.devtools.build.lib.analysis.config.ToolchainTypeRequirement;
 import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.cmdline.RepositoryName;
 import com.google.devtools.build.lib.collect.nestedset.NestedSet;
@@ -68,6 +67,7 @@
 import com.google.devtools.build.lib.rules.java.JavaConfiguration;
 import com.google.devtools.build.lib.rules.java.JavaGenJarsProvider;
 import com.google.devtools.build.lib.rules.java.JavaInfo;
+import com.google.devtools.build.lib.rules.java.JavaRuleClasses;
 import com.google.devtools.build.lib.rules.java.JavaRuntimeInfo;
 import com.google.devtools.build.lib.rules.java.JavaSemantics;
 import com.google.devtools.build.lib.rules.objc.J2ObjcSource.SourceType;
@@ -118,13 +118,13 @@ private static LabelLateBoundDefault<ProtoConfiguration> getProtoToolchainLabel(
   private final RepositoryName toolsRepository;
   private final Label ccToolchainType;
   private final LabelLateBoundDefault<CppConfiguration> ccToolchain;
-  private final Label javaToolchain;
+  private final ToolchainTypeRequirement javaToolchainTypeRequirement;
 
   public J2ObjcAspect(RuleDefinitionEnvironment env, CppSemantics cppSemantics) {
     this.toolsRepository = checkNotNull(env.getToolsRepository());
     this.ccToolchainType = CppRuleClasses.ccToolchainTypeAttribute(env);
     this.ccToolchain = CppRuleClasses.ccToolchainAttribute(env);
-    this.javaToolchain = JavaSemantics.javaToolchainAttribute(env);
+    this.javaToolchainTypeRequirement = JavaRuleClasses.javaToolchainTypeRequirement(env);
   }
 
   /** Returns whether this aspect allows proto services to be generated from this proto rule */
@@ -149,7 +149,9 @@ public AspectDefinition getDefinition(AspectParameters aspectParameters) {
             J2ObjcConfiguration.class,
             ObjcConfiguration.class,
             ProtoConfiguration.class)
-        .addToolchainTypes(CppRuleClasses.ccToolchainTypeRequirement(ccToolchainType))
+        .addToolchainTypes(
+            CppRuleClasses.ccToolchainTypeRequirement(ccToolchainType),
+            javaToolchainTypeRequirement)
         .add(
             attr("$grep_includes", LABEL)
                 .cfg(ExecutionTransitionFactory.create())
@@ -222,10 +224,8 @@ public AspectDefinition getDefinition(AspectParameters aspectParameters) {
                         toolsRepository + "//tools/j2objc:j2objc_proto_toolchain")))
         .add(attr(":j2objc_cc_toolchain", LABEL).value(ccToolchain))
         .add(
-            attr(JAVA_TOOLCHAIN_ATTRIBUTE_NAME, LABEL)
-                .useOutputLicenses()
-                .mandatoryProviders(ToolchainInfo.PROVIDER.id())
-                .value(javaToolchain))
+            attr(JavaRuleClasses.JAVA_TOOLCHAIN_TYPE_ATTRIBUTE_NAME, LABEL)
+                .value(javaToolchainTypeRequirement.toolchainType()))
         .build();
   }
 

src/main/starlark/builtins_bzl/common/java/android_lint.bzl

@@ -52,7 +52,7 @@ def android_lint_action(ctx, source_files, source_jars, compilation_info):
     if not (source_files or source_jars):
         return None
 
-    toolchain = ctx.attr._java_toolchain[java_common.JavaToolchainInfo]
+    toolchain = semantics.find_java_toolchain(ctx)
     java_runtime = toolchain.java_runtime
     linter = toolchain.android_linter()
     if not linter:
@@ -129,10 +129,3 @@ def android_lint_action(ctx, source_files, source_jars, compilation_info):
         execution_requirements = {"supports-workers": "1"},
     )
     return android_lint_out
-
-ANDROID_LINT_IMPLICIT_ATTRS = {
-    "_java_toolchain": attr.label(
-        default = semantics.JAVA_TOOLCHAIN_LABEL,
-        providers = [java_common.JavaToolchainInfo],
-    ),
-}

src/main/starlark/builtins_bzl/common/java/compile_action.bzl

@@ -150,7 +150,7 @@ def compile_action(
         exported_plugins = exported_plugins,
         javac_opts = [ctx.expand_location(opt) for opt in javacopts],
         neverlink = neverlink,
-        java_toolchain = ctx.attr._java_toolchain[java_common.JavaToolchainInfo],
+        java_toolchain = semantics.find_java_toolchain(ctx),
         output = output_class_jar,
         output_source_jar = output_source_jar,
         strict_deps = _filter_strict_deps(strict_deps),
@@ -169,10 +169,3 @@ def compile_action(
     )
 
     return java_info, compilation_info
-
-COMPILE_ACTION_IMPLICIT_ATTRS = {
-    "_java_toolchain": attr.label(
-        default = semantics.JAVA_TOOLCHAIN_LABEL,
-        providers = [java_common.JavaToolchainInfo],
-    ),
-}

src/main/starlark/builtins_bzl/common/java/java_common.bzl

@@ -18,7 +18,7 @@ Common code for reuse across java_* rules
 
 load(":common/rule_util.bzl", "merge_attrs")
 load(":common/java/android_lint.bzl", "android_lint_action")
-load(":common/java/compile_action.bzl", "COMPILE_ACTION_IMPLICIT_ATTRS", "compile_action")
+load(":common/java/compile_action.bzl", "compile_action")
 load(":common/java/java_semantics.bzl", "semantics")
 load(":common/java/proguard_validation.bzl", "VALIDATE_PROGUARD_SPECS_IMPLICIT_ATTRS", "validate_proguard_specs")
 
@@ -261,12 +261,16 @@ def construct_defaultinfo(ctx, files_to_build, files, neverlink, *extra_attrs):
     return default_info
 
 BASIC_JAVA_LIBRARY_IMPLICIT_ATTRS = merge_attrs(
-    COMPILE_ACTION_IMPLICIT_ATTRS,
     {
         "_java_plugins": attr.label(
             default = semantics.JAVA_PLUGINS_FLAG_ALIAS_LABEL,
             providers = [JavaPluginInfo],
         ),
+        # TODO(b/245144242): Used by IDE integration, remove when toolchains are used
+        "_java_toolchain": attr.label(
+            default = semantics.JAVA_TOOLCHAIN_LABEL,
+            providers = [java_common.JavaToolchainInfo],
+        ),
     },
 )
 

src/main/starlark/builtins_bzl/common/java/java_library.bzl

@@ -164,6 +164,7 @@ JAVA_LIBRARY_ATTRS = merge_attrs(
         "add_exports": attr.string_list(),
         "add_opens": attr.string_list(),
         "licenses": attr.license() if hasattr(attr, "license") else attr.string_list(),
+        "_java_toolchain_type": attr.label(default = semantics.JAVA_TOOLCHAIN_TYPE),
     },
 )
 
@@ -177,4 +178,5 @@ java_library = rule(
     },
     fragments = ["java", "cpp"],
     compile_one_filetype = [".java"],
+    toolchains = [semantics.JAVA_TOOLCHAIN],
 )

src/main/starlark/builtins_bzl/common/java/java_plugin.bzl

@@ -19,6 +19,7 @@ Definition of java_plugin rule.
 load(":common/java/java_common.bzl", "basic_java_library", "construct_defaultinfo")
 load(":common/java/java_library.bzl", "JAVA_LIBRARY_ATTRS", "JAVA_LIBRARY_IMPLICIT_ATTRS")
 load(":common/rule_util.bzl", "merge_attrs")
+load(":common/java/java_semantics.bzl", "semantics")
 
 JavaPluginInfo = _builtins.toplevel.JavaPluginInfo
 
@@ -137,4 +138,5 @@ java_plugin = rule(
         "sourcejar": "lib%{name}-src.jar",
     },
     fragments = ["java", "cpp"],
+    toolchains = [semantics.JAVA_TOOLCHAIN],
 )

src/main/starlark/builtins_bzl/common/java/java_semantics.bzl

@@ -38,8 +38,20 @@ def _get_coverage_runner(ctx):
 def _add_constraints(java_info, constraints):
     return java_info
 
+def _find_java_toolchain(ctx):
+    return ctx.toolchains["@bazel_tools//tools/jdk:toolchain_type"].java
+
+def _find_java_runtime_toolchain(ctx):
+    return ctx.toolchains["@bazel_tools//tools/jdk:runtime_toolchain_type"].java_runtime
+
 semantics = struct(
     JAVA_TOOLCHAIN_LABEL = "@bazel_tools//tools/jdk:current_java_toolchain",
+    JAVA_TOOLCHAIN_TYPE = "@bazel_tools//tools/jdk:toolchain_type",
+    JAVA_TOOLCHAIN = _builtins.toplevel.config_common.toolchain_type("@bazel_tools//tools/jdk:toolchain_type", mandatory = True),
+    find_java_toolchain = _find_java_toolchain,
+    JAVA_RUNTIME_TOOLCHAIN_TYPE = "@bazel_tools//tools/jdk:runtime_toolchain_type",
+    JAVA_RUNTIME_TOOLCHAIN = _builtins.toplevel.config_common.toolchain_type("@bazel_tools//tools/jdk:runtime_toolchain_type", mandatory = True),
+    find_java_runtime_toolchain = _find_java_runtime_toolchain,
     JAVA_PLUGINS_FLAG_ALIAS_LABEL = "@bazel_tools//tools/jdk:java_plugins_flag_alias",
     PROGUARD_ALLOWLISTER_LABEL = "@bazel_tools//tools/jdk:proguard_whitelister",
     EXTRA_SRCS_TYPES = [],