Fixed NPE if ranged loop-variable is not declared. Closes #333

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

@@ -1207,6 +1207,9 @@ public class Pass0GenerateStatementSequence extends KickCParserBaseVisitor<Objec
          addDirectives(lValue, varType, varDirectives, statementSource);
       } else {
          lValue = getCurrentScope().getVariable(varName);
+         if(lValue==null) {
+            throw new CompileError("Error! Loop variable not declared "+varName, statementSource);
+         }
       }
       exitDeclTypes();
       KickCParser.StmtForContext stmtForCtx = (KickCParser.StmtForContext) ctx.getParent();

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

@@ -2410,6 +2410,11 @@ public class TestPrograms {
       compileAndCompare("double-assignment");
    }
 
+   @Test
+   public void testLoopNpe() throws IOException, URISyntaxException {
+      assertError("loop-npe", "Error! Loop variable not declared");
+   }
+
    @Test
    public void testConstWordPointer() throws IOException, URISyntaxException {
       compileAndCompare("const-word-pointer");

src/test/kc/loop-npe.kc

@@ -0,0 +1,13 @@
+// Illustrated compiler NPE when doing ranged loop without declaring the loop variable.
+
+
+void main() {
+    byte* SCREEN = 0x0400;
+    clear_line(SCREEN);
+}
+
+
+void clear_line(byte *line) {
+    for (i: 0..39)
+        line[i] = 0;
+}