From e3548384916e8a8e0d5013034b844c63afcd8d4b Mon Sep 17 00:00:00 2001
From: Daniel Holle <dholle@hb.dhbw-stuttgart.de>
Date: Thu, 14 Mar 2024 10:23:19 +0100
Subject: [PATCH] Use wildcard constraint in foreach, fixes #291 and hopefully
 doesn't break anything

---
 resources/bytecode/javFiles/ForEach.jav                | 10 +++++++++-
 src/main/java/de/dhbwstuttgart/bytecode/Codegen.java   |  1 +
 .../syntaxtree/visual/OutputGenerator.java             | 10 +++++++++-
 .../dhbwstuttgart/typeinference/typeAlgo/TYPEStmt.java |  2 +-
 4 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/resources/bytecode/javFiles/ForEach.jav b/resources/bytecode/javFiles/ForEach.jav
index 32b1eb8d..301066ad 100644
--- a/resources/bytecode/javFiles/ForEach.jav
+++ b/resources/bytecode/javFiles/ForEach.jav
@@ -1,8 +1,9 @@
 import java.util.ArrayList;
 import java.lang.Integer;
+import java.lang.Number;
 
 public class ForEach {
-    m() {
+    public m() {
         var list = new ArrayList<>();
         list.add(1); list.add(2); list.add(3);
 
@@ -12,4 +13,11 @@ public class ForEach {
         }
         return sum;
     }
+
+    public m2() {
+        var list = new ArrayList<? extends Number>();
+
+        for (Number n : list) {
+        }
+    }
 }
\ No newline at end of file
diff --git a/src/main/java/de/dhbwstuttgart/bytecode/Codegen.java b/src/main/java/de/dhbwstuttgart/bytecode/Codegen.java
index b28fe67d..6ea6e616 100644
--- a/src/main/java/de/dhbwstuttgart/bytecode/Codegen.java
+++ b/src/main/java/de/dhbwstuttgart/bytecode/Codegen.java
@@ -1073,6 +1073,7 @@ public class Codegen {
         mv.visitJumpInsn(IFEQ, end);
         mv.visitInsn(DUP);
         mv.visitMethodInsn(INVOKEINTERFACE, "java/util/Iterator", "next", "()Ljava/lang/Object;", true);
+        mv.visitTypeInsn(CHECKCAST, localVar.type().getInternalName());
         mv.visitVarInsn(ASTORE, localVar.index);
 
         generate(state, forEach.body());
diff --git a/src/main/java/de/dhbwstuttgart/syntaxtree/visual/OutputGenerator.java b/src/main/java/de/dhbwstuttgart/syntaxtree/visual/OutputGenerator.java
index e68adda6..638d13d6 100644
--- a/src/main/java/de/dhbwstuttgart/syntaxtree/visual/OutputGenerator.java
+++ b/src/main/java/de/dhbwstuttgart/syntaxtree/visual/OutputGenerator.java
@@ -246,7 +246,15 @@ public class OutputGenerator implements ASTVisitor {
 
     @Override
     public void visit(ForEachStmt forEachStmt) {
-
+        out.append("for(");
+        forEachStmt.statement.accept(this);
+        out.append(" : ");
+        forEachStmt.expression.accept(this);
+        out.append(")\n");
+        tab();
+        out.append(tabs);
+        forEachStmt.block.accept(this);
+        untab();
     }
 
     @Override
diff --git a/src/main/java/de/dhbwstuttgart/typeinference/typeAlgo/TYPEStmt.java b/src/main/java/de/dhbwstuttgart/typeinference/typeAlgo/TYPEStmt.java
index 929b3726..3811c59c 100644
--- a/src/main/java/de/dhbwstuttgart/typeinference/typeAlgo/TYPEStmt.java
+++ b/src/main/java/de/dhbwstuttgart/typeinference/typeAlgo/TYPEStmt.java
@@ -138,7 +138,7 @@ public class TYPEStmt implements StatementVisitor {
 
     @Override
     public void visit(ForEachStmt forEachStmt) {
-        var iterableType = new RefType(ASTFactory.createClass(java.lang.Iterable.class).getClassName(), Arrays.asList(forEachStmt.statement.getType()), new NullToken());
+        var iterableType = new RefType(ASTFactory.createClass(java.lang.Iterable.class).getClassName(), Arrays.asList(new ExtendsWildcardType(forEachStmt.statement.getType(), new NullToken())), new NullToken());
         constraintsSet.addUndConstraint(new Pair(forEachStmt.expression.getType(), iterableType, PairOperator.SMALLERDOT, loc(forEachStmt.getOffset())));
         forEachStmt.statement.accept(this);
         forEachStmt.expression.accept(this);