Add check for missing interface methods, fixes #423

resources/bytecode/javFiles/Bug421.jav

@@ -1,3 +0,0 @@
-public class Bug421 {
-    public m() { return 1 } // Missing semicolon
-}

resources/bytecode/javFiles/Bug423.jav

@@ -0,0 +1,5 @@
+import java.lang.Integer;
+
+interface Bug423I { Integer f(); }
+
+public class Bug423 implements Bug423I { }

resources/bytecode/javFiles/Interfaces.jav

@@ -15,6 +15,7 @@ interface C {
 }
 
 class ClassX implements A {
+    void method1() {}
 }
 
 record ClassY(Integer myInt) implements C {}

src/main/java/de/dhbwstuttgart/bytecode/Codegen.java

@@ -1846,6 +1846,35 @@ public class Codegen {
         clazz.constructors().forEach(this::generateConstructor);
         clazz.methods().forEach(this::generateMethod);
 
+        // Check if non abstract class implements all interface methods
+        if ((access & ACC_ABSTRACT) == 0) {
+            for (var intf : clazz.implementingInterfaces()) {
+                var intfClass = compiler.getClass(new JavaClassName(intf.name()));
+                for (var method : intfClass.getMethods()) {
+                    if ((method.modifier & ACC_ABSTRACT) != 0) {
+                        // Check if the method is implemented in the current class
+                        // TODO This is duplicate code, we should probably refactor instances of this pattern
+                        var foundMethods = clazz.methods().stream().filter(m -> {
+                            if (!m.name().equals(method.name)) return false;
+                            if (m.signature().parameters().size() != method.getParameterList().getFormalparalist().size())
+                                return false;
+                            for (var i = 0; i < m.signature().parameters().size(); i++) {
+                                var param1 = m.signature().parameters().get(i).pattern().type();
+                                var param2 = converter.convert(
+                                    method.getParameterList().getParameterAt(i).getType(),
+                                    ASTToTargetAST.Generics.nullGenerics(compiler).javaGenerics());
+                                if (!param1.equals(param2)) return false;
+                            }
+                            return true;
+                        }).toList();
+                        if (foundMethods.size() != 1) {
+                            throw new CodeGenException("Class " + clazz.qualifiedName() + " does not implement method " + method.name + " from interface " + intfClass.getClassName());
+                        }
+                    }
+                }
+            }
+        }
+
         if (clazz.staticConstructor() != null)
             generateStaticConstructor(clazz.staticConstructor());
 

src/main/java/de/dhbwstuttgart/exceptions/ParserError.java

@@ -2,8 +2,9 @@ package de.dhbwstuttgart.exceptions;
 
 import org.antlr.v4.runtime.Token;
 
-public class ParserError extends RuntimeException{
-	public ParserError(String message) {
-		super(message);
+public class ParserError extends TypeinferenceException{
+
+	public ParserError(Token offset){
+		super("Fehler beim Parsen", offset);
 	}
 }

src/main/java/de/dhbwstuttgart/parser/JavaTXParser.java

@@ -1,7 +1,6 @@
 package de.dhbwstuttgart.parser;
 
 import de.dhbwstuttgart.environment.CompilationEnvironment;
-import de.dhbwstuttgart.exceptions.ParserError;
 import de.dhbwstuttgart.parser.SyntaxTreeGenerator.SyntaxTreeGenerator;
 import de.dhbwstuttgart.parser.antlr.Java17Lexer;
 import de.dhbwstuttgart.parser.antlr.Java17Parser;
@@ -9,7 +8,9 @@ import de.dhbwstuttgart.parser.scope.JavaClassRegistry;
 import de.dhbwstuttgart.syntaxtree.SourceFile;
 
 import de.dhbwstuttgart.util.Logger;
-import org.antlr.v4.runtime.*;
+import org.antlr.v4.runtime.CharStream;
+import org.antlr.v4.runtime.CharStreams;
+import org.antlr.v4.runtime.CommonTokenStream;
 
 import java.io.*;
 import java.nio.charset.StandardCharsets;
@@ -20,25 +21,13 @@ public class JavaTXParser {
 
     public static Logger logger = new Logger("Parser");
 
-    public static class ThrowingErrorListener extends BaseErrorListener {
-
-        @Override
-        public void syntaxError(Recognizer<?, ?> recognizer, Object offendingSymbol,
-                                int line, int charPositionInLine, String msg, RecognitionException e) {
-            throw new ParserError("Syntax error at line " + line +  ":" + charPositionInLine + " - " + msg);
-        }
-    }
-
     public static Java17Parser.SourceFileContext parse(File source) throws IOException, java.lang.ClassNotFoundException {
         InputStream stream = new FileInputStream(source);
         // DEPRECATED: ANTLRInputStream input = new ANTLRInputStream(stream);
-        var errorListener = new ThrowingErrorListener();
         CharStream input = CharStreams.fromStream(stream);
         Java17Lexer lexer = new Java17Lexer(input);
-        lexer.addErrorListener(errorListener);
         CommonTokenStream tokens = new CommonTokenStream(lexer);
         Java17Parser parser = new Java17Parser(tokens);
-        parser.addErrorListener(errorListener);
         return parser.sourceFile();
         /*
          * SyntaxTreeGenerator generator = new SyntaxTreeGenerator(environment.getRegistry(source)); return generator.convert(tree);

src/test/java/TestComplete.java

@@ -1,7 +1,6 @@
 
 import de.dhbwstuttgart.bytecode.CodeGenException;
 import de.dhbwstuttgart.core.ConsoleInterface;
-import de.dhbwstuttgart.exceptions.ParserError;
 import de.dhbwstuttgart.exceptions.WarningsException;
 import de.dhbwstuttgart.util.Logger;
 import de.dhbwstuttgart.util.Logger.LogLevel;
@@ -1707,12 +1706,12 @@ public class TestComplete {
     }
 
     @Test
-    public void testBug421() throws Exception {
+    public void testBug423() throws Exception {
         try {
-            var classFiles = generateClassFiles(createClassLoader(), "Bug421.jav");
-            fail("Shouldn't compile!");
-        } catch (ParserError e) {
-            assertEquals("Syntax error at line 2:26 - no viable alternative at input 'm() { return 1 }'", e.getMessage());
+            var classFiles = generateClassFiles(createClassLoader(), "Bug423.jav");
+            fail("No exception thrown!");
+        } catch (CodeGenException e) {
+            assertEquals("Class Bug423 does not implement method f from interface Bug423I", e.getMessage());
         }
     }
 }