Create warning when parsing targets too new Java versions

Fixes eclipse-jdt#3018

org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/core/compiler/IProblem.java

@@ -2226,6 +2226,8 @@ public interface IProblem {
 	int PreviewAPIUsed = Compliance + 1108;
 	/** @since 3.39*/
 	int JavaVersionNotSupported = Compliance + 1109;
+	/** @since 3.40*/
+	int JavaVersionTooRecent = Compliance + 1110;
 
 	/** @since 3.13 */
 	int UnlikelyCollectionMethodArgumentType = 1200;

org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/impl/CompilerOptions.java

@@ -432,6 +432,14 @@ public class CompilerOptions {
 	public long complianceLevel;
 	/** Java source level, refers to a JDK version, e.g. {@link ClassFileConstants#JDK1_4} */
 	public long sourceLevel;
+	/**
+	 * Initially requested source version, not necessarily consistent with {@link #sourceLevel} as
+	 * sourceLevel forcibly contain a version that is compatible with ECJ.
+	 * <p>Consumers are free to use {@code sourceLevel} or this
+	 * {@code requestedSourceVersion} value to decide of their behavior.</p>
+	 * <p>May be {@code null}.</p>
+	 */
+	public String requestedSourceVersion;
 	/** VM target level, refers to a JDK version, e.g. {@link ClassFileConstants#JDK1_4} */
 	public long targetJDK;
 	/** Source encoding format */
@@ -1764,7 +1772,7 @@ public void set(Map<String, String> optionsMap) {
 			long level = versionToJdkLevel(optionValue);
 			if (level != 0) this.complianceLevel = level;
 		}
-		if ((optionValue = optionsMap.get(OPTION_Source)) != null) {
+		if ((this.requestedSourceVersion = optionValue = optionsMap.get(OPTION_Source)) != null) {
 			long level = versionToJdkLevel(optionValue);
 			if (level != 0) this.sourceLevel = level;
 		}

org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/parser/Parser.java

@@ -37,6 +37,7 @@
 import java.io.FileWriter;
 import java.io.IOException;
 import java.io.InputStream;
+import java.lang.Runtime.Version;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
@@ -12844,6 +12845,21 @@ public CompilationUnitDeclaration parse(
 					compilationResult,
 					0);
 
+		var problemReporterContext = this.problemReporter.referenceContext;
+		this.problemReporter.referenceContext = this.referenceContext;
+		if (this.options.requestedSourceVersion != null) {
+			try {
+				var requestedVersion = Version.parse(this.options.requestedSourceVersion);
+				var latestVersion = Version.parse(CompilerOptions.getLatestVersion());
+				if (requestedVersion.compareTo(latestVersion) > 0) {
+					this.problemReporter.tooRecentJavaVersion(requestedVersion.toString(), latestVersion.toString());
+				}
+			} catch (Exception ex) {
+				this.problemReporter.abortDueToInternalError(ex.getMessage());
+			}
+		}
+		this.problemReporter.referenceContext = problemReporterContext;
+
 		/* scanners initialization */
 		char[] contents;
 		try {

org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/problem/ProblemReporter.java

@@ -923,6 +923,16 @@ public void abortDueToNotSupportedJavaVersion(String notSupportedVersion, String
 			0,
 			0);
 }
+public void tooRecentJavaVersion(String notSupportedVersion, String firstSupportedVersion) {
+	String[] args = new String[] {notSupportedVersion, firstSupportedVersion};
+	this.handle(
+			IProblem.JavaVersionTooRecent,
+			args,
+			args,
+			ProblemSeverities.Warning,
+			0,
+			0);
+}
 public void abstractMethodCannotBeOverridden(SourceTypeBinding type, MethodBinding concreteMethod) {
 
 	this.handle(

org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/problem/messages.properties

@@ -907,6 +907,7 @@
 1107 = The Java feature ''{0}'' is only available with source level {1} and above
 1108 = You are using an API that is part of a preview feature and may be removed in future
 1109 = Compiling for Java version ''{0}'' is no longer supported. Minimal supported version is ''{1}''
+1110 = Compiling for Java version ''{0}'' is not supported yet. Using ''{1}'' instead
 # more programming problems:
 1200 = Unlikely argument type {0} for {1} on a {2}
 1201 = Unlikely argument type for equals(): {0} seems to be unrelated to {2}

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

@@ -1249,6 +1249,7 @@ class ProblemAttributes {
 	    expectedProblemAttributes.put("FeatureNotSupported", new ProblemAttributes(CategorizedProblem.CAT_COMPLIANCE));
 	    expectedProblemAttributes.put("PreviewAPIUsed", new ProblemAttributes(CategorizedProblem.CAT_COMPLIANCE));
 	    expectedProblemAttributes.put("JavaVersionNotSupported", new ProblemAttributes(CategorizedProblem.CAT_COMPLIANCE));
+	    expectedProblemAttributes.put("JavaVersionTooRecent", new ProblemAttributes(CategorizedProblem.CAT_COMPLIANCE));
 	    expectedProblemAttributes.put("SwitchExpressionsYieldIncompatibleResultExpressionTypes", new ProblemAttributes(CategorizedProblem.CAT_TYPE));
 	    expectedProblemAttributes.put("SwitchExpressionsYieldEmptySwitchBlock", new ProblemAttributes(CategorizedProblem.CAT_SYNTAX));
 	    expectedProblemAttributes.put("SwitchExpressionsYieldNoResultExpression", new ProblemAttributes(CategorizedProblem.CAT_INTERNAL));
@@ -2382,6 +2383,7 @@ class ProblemAttributes {
 	    expectedProblemAttributes.put("FeatureNotSupported", SKIP);
 	    expectedProblemAttributes.put("PreviewAPIUsed", SKIP);
 	    expectedProblemAttributes.put("JavaVersionNotSupported", SKIP);
+	    expectedProblemAttributes.put("JavaVersionTooRecent", SKIP);
 	    expectedProblemAttributes.put("SwitchExpressionsYieldIncompatibleResultExpressionTypes", SKIP);
 	    expectedProblemAttributes.put("SwitchExpressionsYieldEmptySwitchBlock", SKIP);
 	    expectedProblemAttributes.put("SwitchExpressionsYieldNoResultExpression", SKIP);