Set Java toolchain source and target version from target Java runtime.

This functionality will enable Bazel to automatically produce target code for detected version of local JDK. PiperOrigin-RevId: 347577778
ptarjan · Dec 15, 2020 · b1e9884 · b1e9884
1 parent 909bec5
commit b1e9884
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Showing 6 changed files with 45 additions and 1 deletion.
diff --git a/src/main/java/com/google/devtools/build/lib/rules/java/JavaRuntime.java b/src/main/java/com/google/devtools/build/lib/rules/java/JavaRuntime.java
@@ -33,6 +33,7 @@
 import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.collect.nestedset.NestedSet;
 import com.google.devtools.build.lib.collect.nestedset.NestedSetBuilder;
+import com.google.devtools.build.lib.packages.Type;
 import com.google.devtools.build.lib.util.OsUtils;
 import com.google.devtools.build.lib.vfs.PathFragment;
 
@@ -102,6 +103,7 @@ public ConfiguredTarget create(RuleContext ruleContext)
 
     JavaRuntimeInfo javaRuntime =
         JavaRuntimeInfo.create(
+            ruleContext.attributes().get("version", Type.STRING),
             filesToBuild,
             middleman,
             javaHome,

diff --git a/src/main/java/com/google/devtools/build/lib/rules/java/JavaRuntimeInfo.java b/src/main/java/com/google/devtools/build/lib/rules/java/JavaRuntimeInfo.java
@@ -38,13 +38,15 @@
 public final class JavaRuntimeInfo extends ToolchainInfo implements JavaRuntimeInfoApi {
 
   public static JavaRuntimeInfo create(
+      String version,
       NestedSet<Artifact> javaBaseInputs,
       NestedSet<Artifact> javaBaseInputsMiddleman,
       PathFragment javaHome,
       PathFragment javaBinaryExecPath,
       PathFragment javaHomeRunfilesPath,
       PathFragment javaBinaryRunfilesPath) {
     return new JavaRuntimeInfo(
+        version,
         javaBaseInputs,
         javaBaseInputsMiddleman,
         javaHome,
@@ -81,6 +83,7 @@ private static JavaRuntimeInfo from(RuleContext ruleContext, String attributeNam
     return (JavaRuntimeInfo) prerequisite.get(ToolchainInfo.PROVIDER);
   }
 
+  private final String version;
   private final NestedSet<Artifact> javaBaseInputs;
   private final NestedSet<Artifact> javaBaseInputsMiddleman;
   private final PathFragment javaHome;
@@ -91,13 +94,15 @@ private static JavaRuntimeInfo from(RuleContext ruleContext, String attributeNam
   @AutoCodec.Instantiator
   @VisibleForSerialization
   JavaRuntimeInfo(
+      String version,
       NestedSet<Artifact> javaBaseInputs,
       NestedSet<Artifact> javaBaseInputsMiddleman,
       PathFragment javaHome,
       PathFragment javaBinaryExecPath,
       PathFragment javaHomeRunfilesPath,
       PathFragment javaBinaryRunfilesPath) {
     super(ImmutableMap.of(), Location.BUILTIN);
+    this.version = version;
     this.javaBaseInputs = javaBaseInputs;
     this.javaBaseInputsMiddleman = javaBaseInputsMiddleman;
     this.javaHome = javaHome;
@@ -106,6 +111,11 @@ private static JavaRuntimeInfo from(RuleContext ruleContext, String attributeNam
     this.javaBinaryRunfilesPath = javaBinaryRunfilesPath;
   }
 
+  /** Release version of the Java runtiem. */
+  public String version() {
+    return version;
+  }
+
   /** All input artifacts in the javabase. */
   public NestedSet<Artifact> javaBaseInputs() {
     return javaBaseInputs;

diff --git a/src/main/java/com/google/devtools/build/lib/rules/java/JavaRuntimeRule.java b/src/main/java/com/google/devtools/build/lib/rules/java/JavaRuntimeRule.java
@@ -52,6 +52,10 @@ public RuleClass build(RuleClass.Builder builder, RuleDefinitionEnvironment env)
         path. In that case, the <code>srcs</code> and <code>java</code> attributes must be empty.
         <!-- #END_BLAZE_RULE.ATTRIBUTE --> */
         .add(attr("java_home", STRING))
+        /* <!-- #BLAZE_RULE(java_runtime).ATTRIBUTE(version) -->
+        The release version of JDK, this is for example 8 for JDK 1.8.0, and 11 for JDK 11.
+        <!-- #END_BLAZE_RULE.ATTRIBUTE --> */
+        .add(attr("version", STRING))
         .add(attr("output_licenses", LICENSE))
         .build();
   }

diff --git a/src/main/java/com/google/devtools/build/lib/rules/java/JavaToolchain.java b/src/main/java/com/google/devtools/build/lib/rules/java/JavaToolchain.java
@@ -149,10 +149,18 @@ public ConfiguredTarget create(RuleContext ruleContext)
   private ImmutableList<String> getJavacOpts(RuleContext ruleContext) {
     ImmutableList.Builder<String> javacopts = ImmutableList.builder();
     String source = ruleContext.attributes().get("source_version", Type.STRING);
+    String target = ruleContext.attributes().get("target_version", Type.STRING);
+    if (!ruleContext.attributes().isAttributeValueExplicitlySpecified("source_version")
+        && !ruleContext.attributes().isAttributeValueExplicitlySpecified("target_version")) {
+      JavaRuntimeInfo targetJavaRuntime =
+          (JavaRuntimeInfo)
+              ruleContext.getPrerequisite("$target_java_runtime", JavaRuntimeInfo.PROVIDER);
+      source = targetJavaRuntime.version();
+      target = source;
+    }
     if (!isNullOrEmpty(source)) {
       javacopts.add("-source").add(source);
     }
-    String target = ruleContext.attributes().get("target_version", Type.STRING);
     if (!isNullOrEmpty(target)) {
       javacopts.add("-target").add(target);
     }

diff --git a/src/main/java/com/google/devtools/build/lib/rules/java/JavaToolchainRule.java b/src/main/java/com/google/devtools/build/lib/rules/java/JavaToolchainRule.java
@@ -30,6 +30,8 @@
 import com.google.devtools.build.lib.analysis.config.ExecutionTransitionFactory;
 import com.google.devtools.build.lib.analysis.config.transitions.NoTransition;
 import com.google.devtools.build.lib.analysis.platform.ToolchainInfo;
+import com.google.devtools.build.lib.packages.Attribute;
+import com.google.devtools.build.lib.packages.AttributeMap;
 import com.google.devtools.build.lib.packages.RuleClass;
 import com.google.devtools.build.lib.util.FileTypeSet;
 import java.util.List;
@@ -295,6 +297,22 @@ The Java target version (e.g., '6' or '7'). It specifies for which Java runtime
                 .mandatoryProviders(ToolchainInfo.PROVIDER.id())
                 .allowedFileTypes(FileTypeSet.ANY_FILE)
                 .useOutputLicenses())
+        .add(
+            attr("$target_java_runtime", LABEL)
+                .value(
+                    new Attribute.ComputedDefault("source_version", "target_version") {
+                      @Override
+                      public Object getDefault(AttributeMap rule) {
+                        if (!rule.isAttributeValueExplicitlySpecified("source_version")
+                            && !rule.isAttributeValueExplicitlySpecified("target_version")) {
+                          return JavaSemantics.jvmAttribute(env);
+                        }
+                        return null;
+                      }
+                    })
+                .mandatoryProviders(ToolchainInfo.PROVIDER.id())
+                .allowedFileTypes(FileTypeSet.ANY_FILE)
+                .useOutputLicenses())
         /* <!-- #BLAZE_RULE(java_toolchain).ATTRIBUTE(android_lint_runner) -->
         Label of the Android Lint runner, if any.
         <!-- #END_BLAZE_RULE.ATTRIBUTE --> */

diff --git a/src/test/java/com/google/devtools/build/lib/rules/java/JavaRuntimeInfoTest.java b/src/test/java/com/google/devtools/build/lib/rules/java/JavaRuntimeInfoTest.java
@@ -29,6 +29,7 @@ public class JavaRuntimeInfoTest {
   public void equalityIsObjectIdentity() {
     JavaRuntimeInfo a =
         JavaRuntimeInfo.create(
+            /* version = */ "",
             NestedSetBuilder.emptySet(Order.STABLE_ORDER),
             NestedSetBuilder.emptySet(Order.STABLE_ORDER),
             PathFragment.create(""),
@@ -37,6 +38,7 @@ public void equalityIsObjectIdentity() {
             PathFragment.create(""));
     JavaRuntimeInfo b =
         JavaRuntimeInfo.create(
+            /* version = */ "",
             NestedSetBuilder.emptySet(Order.STABLE_ORDER),
             NestedSetBuilder.emptySet(Order.STABLE_ORDER),
             PathFragment.create(""),