[GR-53454] Warn when @ReportPolymorphism is used incorrectly

* Remove duplicate .required() check.

compiler/src/jdk.graal.compiler.test/src/jdk/graal/compiler/truffle/test/NodeSplittingStrategyTest.java

@@ -24,6 +24,7 @@
  */
 package jdk.graal.compiler.truffle.test;
 
+import com.oracle.truffle.api.dsl.test.ExpectWarning;
 import org.graalvm.polyglot.Context;
 import org.junit.Assert;
 import org.junit.Before;
@@ -449,6 +450,7 @@ public void testTwoMegamorpicSpec2() {
  testMegamorphicHelper(callTarget, args);
  }
 
+ @ExpectWarning("This node uses @ReportPolymorphism on the class and @ReportPolymorphism.Megamorphic on some specializations, the latter annotation has no effect. Remove one of the annotations to resolve this.")
  @NodeChild
  abstract static class PolymorphicAndMegamorpic extends SplittingTestNode {
 

truffle/CHANGELOG.md

@@ -26,6 +26,7 @@ This changelog summarizes major changes between Truffle versions relevant to lan
 * GR-40931 Virtual threads with a polyglot context are now experimentally supported on HotSpot. Experimental because access to caller frames in write or materialize mode is not yet supported and maximum 65535 threads concurrently accessing the context.
 * GR-40931 Using virtual threads in a native-image will now emulate virtual threads using platform threads until Loom support for Truffle languages in native-image is implemented.
 * GR-40931 Added [`TruffleThreadBuilder#virtual()`](https://www.graalvm.org/truffle/javadoc/com/oracle/truffle/api/TruffleThreadBuilder.html#virtual(boolean)) for languages to create virtual threads.
+* GR-53454 Added warning in the annotation processor when `@ReportPolymorphism` is used incorrectly.
 
 ## Version 24.0.0
 

truffle/src/com.oracle.truffle.dsl.processor/src/com/oracle/truffle/dsl/processor/TruffleSuppressedWarnings.java

@@ -65,6 +65,7 @@ private TruffleSuppressedWarnings() {
  public static final String NEVERDEFAULT = "truffle-neverdefault";
  public static final String INLINING_RECOMMENDATION = "truffle-inlining";
  public static final String SHARING_RECOMMENDATION = "truffle-sharing";
+ public static final String SPLITTING = "truffle-splitting";
  public static final String ABSTRACT_LIBRARY_EXPORT = "truffle-abstract-export";
  public static final String ASSUMPTION = "truffle-assumption";
  public static final String GUARD = "truffle-guard";

truffle/src/com.oracle.truffle.dsl.processor/src/com/oracle/truffle/dsl/processor/generator/FlatNodeGenFactory.java

@@ -3018,9 +3018,7 @@ private CodeExecutableElement createExecuteAndSpecialize(boolean inlined) {
 
  if (reportPolymorphismAction.required()) {
  builder.end().startFinallyBlock();
- if (reportPolymorphismAction.required()) {
- generateCheckNewPolymorphismState(builder, frameState, reportPolymorphismAction);
- }
+ generateCheckNewPolymorphismState(builder, frameState, reportPolymorphismAction);
  builder.end();
  }
 

truffle/src/com.oracle.truffle.dsl.processor/src/com/oracle/truffle/dsl/processor/model/SpecializationData.java

@@ -366,6 +366,7 @@ public void setReachesFallback(boolean reachesFallback) {
  this.reachesFallback = reachesFallback;
  }
 
+ /** == [email protected]. */
  public boolean isReportPolymorphism() {
  return reportPolymorphism;
  }

truffle/src/com.oracle.truffle.dsl.processor/src/com/oracle/truffle/dsl/processor/parser/NodeParser.java

@@ -435,6 +435,7 @@ public NodeData parseNode(TypeElement originalTemplateType) {
  verifyConstructors(node);
  verifySpecializationThrows(node);
  verifyFrame(node);
+ verifyReportPolymorphism(node);
 
  if (isGenerateSlowPathOnly(node)) {
  removeFastPathSpecializations(node, node.getSharedCaches());
@@ -4429,6 +4430,26 @@ private static void verifyFrame(NodeData node) {
  }
  }
 
+ private static void verifyReportPolymorphism(NodeData node) {
+ if (node.isReportPolymorphism()) {
+ List<SpecializationData> reachableSpecializations = node.getReachableSpecializations();
+ if (reachableSpecializations.size() == 1 && reachableSpecializations.get(0).getMaximumNumberOfInstances() == 1) {
+ node.addSuppressableWarning(TruffleSuppressedWarnings.SPLITTING,
+ "This node uses @ReportPolymorphism but has a single specialization instance, so the annotation has no effect. Remove the annotation or move it to another node to resolve this.");
+ }
+
+ if (reachableSpecializations.stream().noneMatch(SpecializationData::isReportPolymorphism)) {
+ node.addSuppressableWarning(TruffleSuppressedWarnings.SPLITTING,
+ "This node uses @ReportPolymorphism but all specializations use @ReportPolymorphism.Exclude. Remove some excludes or do not use ReportPolymorphism at all for this node to resolve this.");
+ }
+
+ if (reachableSpecializations.stream().anyMatch(SpecializationData::isReportMegamorphism)) {
+ node.addSuppressableWarning(TruffleSuppressedWarnings.SPLITTING,
+ "This node uses @ReportPolymorphism on the class and @ReportPolymorphism.Megamorphic on some specializations, the latter annotation has no effect. Remove one of the annotations to resolve this.");
+ }
+ }
+ }
+
  private static String createMethodSignature(final ExecutableElement method) {
  final StringBuilder result = new StringBuilder();
  result.append(getSimpleName(method.getReturnType())).append(' ').append(getSimpleName((TypeElement) method.getEnclosingElement())).append("::").append(