Added proper error when returning value from void function. Closes #400

src/main/java/dk/camelot64/kickc/passes/Pass0GenerateStatementSequence.java

@@ -1678,6 +1678,9 @@ public class Pass0GenerateStatementSequence extends KickCParserBaseVisitor<Objec
       KickCParser.CommaExprContext exprCtx = ctx.commaExpr();
       RValue rValue;
       if(exprCtx != null) {
+         if(SymbolType.VOID.equals(procedure.getReturnType())) {
+            throw new CompileError("Error! Return value from void function "+procedure.getFullName(), new StatementSource(ctx));
+         }
          PrePostModifierHandler.addPreModifiers(this, exprCtx, new StatementSource(ctx));
          rValue = (RValue) this.visit(exprCtx);
          Variable returnVar = procedure.getLocalVariable("return");

src/test/java/dk/camelot64/kickc/test/TestPrograms.java

@@ -3845,6 +3845,11 @@ public class TestPrograms {
       assertError("noreturn.c", "Method must end with a return statement", false);
    }
 
+   @Test
+   public void testReturnFromVoid() throws IOException, URISyntaxException {
+      assertError("returnfromvoid.c", "Error! Return value from void function");
+   }
+
    @Test
    public void testProcedureNotFound() throws IOException, URISyntaxException {
       assertError("procedurenotfound.c", "Called procedure not found");

src/test/kc/returnfromvoid.c

@@ -0,0 +1,9 @@
+// Return a value from a void function
+
+void main() {
+    print();
+}
+
+void print() {
+    return 2;
+}