Bug 545605 - Adjust ecj to change in JVMS 4.7.18./19. (eclipse-jdt#2628)

Accept class files with mismatching parameter count vis-a-vis parameter annotations (which is legal since Java 9).

Also introduces system property jdt.reject.parameterAnnotations.countMismatch to get back the previous error reporting.

fixes eclipse-jdt#2625

org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/classfmt/MethodInfoWithParameterAnnotations.java

@@ -26,25 +26,29 @@ class MethodInfoWithParameterAnnotations extends MethodInfoWithAnnotations {
 }
 @Override
 public IBinaryAnnotation[] getParameterAnnotations(int index, char[] classFileName) {
-	try {
-		return this.parameterAnnotations == null ? null : this.parameterAnnotations[index];
-	} catch (ArrayIndexOutOfBoundsException aioobe) {
-		// detailed reporting to track down https://bugs.eclipse.org/474081
-		StringBuilder message = new StringBuilder("Mismatching number of parameter annotations, "); //$NON-NLS-1$
-		message.append(index);
-		message.append('>');
-		message.append(this.parameterAnnotations.length-1);
-		message.append(" in "); //$NON-NLS-1$
-		message.append(getSelector());
-		char[] desc = getGenericSignature();
-		if (desc != null)
-			message.append(desc);
-		else
-			message.append(getMethodDescriptor());
-		if (classFileName != null)
-			message.append(" in ").append(classFileName); //$NON-NLS-1$
-		throw new IllegalStateException(message.toString(), aioobe);
+	if (this.parameterAnnotations != null) {
+		if (index < this.parameterAnnotations.length) {
+			return this.parameterAnnotations[index];
+		}
+		if (Boolean.getBoolean("jdt.reject.parameterAnnotations.countMismatch")) { //$NON-NLS-1$
+			// detailed reporting to track down https://bugs.eclipse.org/474081
+			StringBuilder message = new StringBuilder("Mismatching number of parameter annotations, "); //$NON-NLS-1$
+			message.append(index);
+			message.append('>');
+			message.append(this.parameterAnnotations.length-1);
+			message.append(" in "); //$NON-NLS-1$
+			message.append(getSelector());
+			char[] desc = getGenericSignature();
+			if (desc != null)
+				message.append(desc);
+			else
+				message.append(getMethodDescriptor());
+			if (classFileName != null)
+				message.append(" in ").append(classFileName); //$NON-NLS-1$
+			throw new IllegalStateException(message.toString());
+		}
 	}
+	return null;
 }
 @Override
 public int getAnnotatedParametersCount() {

org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/ClassFileReaderTest_1_8.java

@@ -31,6 +31,7 @@
 @SuppressWarnings({ "rawtypes" })
 public class ClassFileReaderTest_1_8 extends AbstractRegressionTest {
 	static {
+//		TESTS_NAMES = new String[] { "testGH2625" };
 	}
 
 	public static Test suite() {
@@ -470,6 +471,33 @@ public void testBug548596() {
 		);
 	}
 
+	public void testGH2625() {
+		String[] libs = getDefaultClassPaths();
+		int len = libs.length;
+		System.arraycopy(libs, 0, libs = new String[len+1], 0, len);
+		// in this jar the num_parameters field of RuntimeInvisibleParameterAnnotations has been manually set to 2
+		// (annotations on the 3-arg method a(Function,Object,long)):
+		libs[libs.length-1] = this.getCompilerTestsPluginDirectoryPath() + File.separator + "workspace" + File.separator + "TestGH2625.jar";
+
+		runConformTest(
+			new String[] {
+				"Test.java",
+				"""
+				import a.A;
+				public class Test {
+					void test(A a) {
+						a.m(null, null, 0L);
+					}
+				}
+				"""
+			},
+			"",
+			libs,
+			false,
+			null
+		);
+	}
+
 	/**
 	 * Produce a nicely formatted type annotation for testing. Exercises the API for type annotations.
 	 * Output examples:<br>