fix: Fix compliance level support for old code (INRIA#4068)

Author: andre15silva

src/main/java/spoon/support/reflect/reference/CtReferenceImpl.java

@@ -31,7 +31,13 @@
 public abstract class CtReferenceImpl extends CtElementImpl implements CtReference, Serializable {
 
 	private static final long serialVersionUID = 1L;
-	private static Collection<String> keywords = fillWithKeywords();
+
+	// See isKeyword for more information on keywords
+	private static final Collection<String> baseKeywords = fillWithBaseKeywords();
+	private static final Collection<String> java2Keywords = Stream.of("strictfp").collect(Collectors.toCollection(HashSet::new));
+	private static final Collection<String> java4Keywords = Stream.of("assert").collect(Collectors.toCollection(HashSet::new));
+	private static final Collection<String> java5Keywords = Stream.of("enum").collect(Collectors.toCollection(HashSet::new));
+	private static final Collection<String> java9Keywords = Stream.of("_").collect(Collectors.toCollection(HashSet::new));
 
 	@MetamodelPropertyField(role = NAME)
 	protected String simplename = "";
@@ -109,9 +115,25 @@ private void checkIdentiferForJLSCorrectness(String simplename) {
 			}
 		}
 	}
+
+	/**
+	 * Keywords list and history selected according to:
+	 * https://docs.oracle.com/en/java/javase/15/docs/specs/sealed-classes-jls.html#jls-3.9
+	 * https://en.wikipedia.org/wiki/List_of_Java_keywords (contains history of revisions)
+	 * and https://docs.oracle.com/javase/tutorial/java/nutsandbolts/_keywords.html (history up to java 8)
+	 *
+	 * @param simplename
+	 * @return true if simplename is a keyword in the current setting (compliance level), false if not
+	 */
 	private boolean isKeyword(String simplename) {
-		return keywords.contains(simplename);
+		int complianceLevel = getFactory().getEnvironment().getComplianceLevel();
+		return (baseKeywords.contains(simplename)
+				|| (complianceLevel >= 2 && java2Keywords.contains(simplename))
+				|| (complianceLevel >= 4 && java4Keywords.contains(simplename))
+				|| (complianceLevel >= 5 && java5Keywords.contains(simplename))
+				|| (complianceLevel >= 9 && java9Keywords.contains(simplename)));
 	}
+
 	private boolean checkAllParts(String[] simplenameParts) {
 		for (String simpleName:simplenameParts) {
 			//because arrays use e.g. int[] and @Number is used for instances of an object e.g. foo@1
@@ -135,13 +157,14 @@ private boolean checkIdentifierChars(String simplename) {
 		);
 	}
 
-	private static Collection<String> fillWithKeywords() {
-		//removed types because needed as ref: "int","short", "char", "void", "byte","float", "true","false","boolean","double","long","class", "null"
-		return Stream.of("abstract", "continue", "for", "new", "switch", "assert", "default", "if", "package", "synchronized",  "do", "goto", "private",
-			"this", "break",  "implements", "protected", "throw", "else", "import", "public", "throws", "case", "enum", "instanceof", "return",
-			"transient", "catch", "extends", "try", "final", "interface", "static", "finally",  "strictfp", "volatile",
-			"const",  "native", "super", "while", "_")
-			.collect(Collectors.toCollection(HashSet::new));
+	private static Collection<String> fillWithBaseKeywords() {
+		// removed types because needed as ref: "int","short", "char", "void", "byte","float", "true","false","boolean","double","long","class", "null"
+		// in the method isKeyword, more keywords are added to the checks based on the compliance level
+		return Stream.of("abstract", "continue", "for", "new", "switch", "default", "if", "package", "synchronized",  "do", "goto", "private",
+				"this", "break",  "implements", "protected", "throw", "else", "import", "public", "throws", "case", "instanceof", "return",
+				"transient", "catch", "extends", "try", "final", "interface", "static", "finally", "volatile",
+				"const",  "native", "super", "while")
+				.collect(Collectors.toCollection(HashSet::new));
 	}
 
 	/**

src/test/java/spoon/test/ctType/CtTypeTest.java

@@ -37,16 +37,12 @@
 import spoon.reflect.visitor.filter.TypeFilter;
 import spoon.test.ctType.testclasses.X;
 
-import java.util.Arrays;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
+import java.util.*;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 import java.util.stream.Collectors;
 
-import static org.hamcrest.CoreMatchers.anyOf;
-import static org.hamcrest.CoreMatchers.equalTo;
+import static org.hamcrest.CoreMatchers.*;
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
@@ -296,4 +292,21 @@ public void testGetAllExecutablesOnTypeImplementingNestedInterface() {
 				equalTo(expectedNumExecutablesPostJDK8))
 		);	
 	}
+
+	/**
+	 * This test captures keyword constraint in CtReferenceImpl based on the compliance level, since the keyword
+	 * "enum" was only introduced in Java 5
+	 */
+	@Test
+	public void testEnumPackage() {
+		final Launcher launcher = new Launcher();
+		launcher.addInputResource("./src/test/resources/keywordCompliance/enum/Foo.java");
+		launcher.getEnvironment().setComplianceLevel(4);
+		launcher.run();
+
+		Collection<CtType<?>> types = launcher.getModel().getAllTypes();
+		assertThat(types.size(), is(1));
+		assertThat(types.stream().findFirst().get(), notNullValue());
+		assertThat(types.stream().findFirst().get().getQualifiedName(), is("keywordCompliance.enum.Foo"));
+	}
 }

src/test/resources/keywordCompliance/enum/Foo.java

@@ -0,0 +1,8 @@
+package keywordCompliance.enum;
+
+public class Foo {
+
+	public Foo() {
+
+	}
+}