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Merged
Frotty merged 3 commits into from
Dec 1, 2025
Merged

Implement capturing outer this in closures #1115

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52d895e
Implement capturing outer this in closures
Frotty Dec 1, 2025
57aeb2d
fix and test for inherited fields
Frotty Dec 1, 2025
6d2d9c5
Update EvaluateExpr.java
Frotty Dec 1, 2025
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19 changes: 16 additions & 3 deletions ...tscript/src/main/java/de/peeeq/wurstscript/intermediatelang/interpreter/EvaluateExpr.java
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Original file line number Diff line number Diff line change
Expand Up @@ -401,20 +401,33 @@ public ILconst get() {

public static ILaddress evaluateLvalue(ImMemberAccess va, ProgramState globalState, LocalState localState) {
ImVar v = va.getVar();
ILconstObject receiver = globalState.toObject(va.getReceiver().evaluate(globalState, localState));
ILconst receiverVal = va.getReceiver().evaluate(globalState, localState);
ILconstObject receiver = globalState.toObject(receiverVal);
if (receiver == null && receiverVal instanceof ILconstInt && va.getReceiver().attrTyp() instanceof ImClassType) {
int objectId = ((ILconstInt) receiverVal).getVal();
if (objectId != 0) {
receiver = globalState.ensureObject((ImClassType) va.getReceiver().attrTyp(),
objectId, va.attrTrace());
}
}
if (receiver == null) {
throw new InterpreterException(va.attrTrace(), "Null pointer dereference");
}
ILconstObject receiverFinal = receiver;
List<Integer> indexes =
va.getIndexes().stream()
.map(ie -> ((ILconstInt) ie.evaluate(globalState, localState)).getVal())
.collect(Collectors.toList());
List<Integer> indexesFinal = indexes;
return new ILaddress() {
@Override
public void set(ILconst value) {
receiver.set(v, indexes, value);
receiverFinal.set(v, indexesFinal, value);
}

@Override
public ILconst get() {
return receiver.get(v, indexes)
return receiverFinal.get(v, indexesFinal)
.orElseGet(() -> va.attrTyp().defaultValue());
}
};
Expand Down
10 changes: 10 additions & 0 deletions ...tscript/src/main/java/de/peeeq/wurstscript/intermediatelang/interpreter/ProgramState.java
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Original file line number Diff line number Diff line change
Expand Up @@ -342,6 +342,16 @@ public ILconst getHandleByIndex(int val) {
return handleMap.get(val);
}

public ILconstObject ensureObject(ImClassType clazz, int objectId, Element trace) {
ILconstObject existing = indexToObject.get(objectId);
if (existing != null) {
return existing;
}
ILconstObject res = new ILconstObject(clazz, objectId, trace);
indexToObject.put(objectId, res);
return res;
}

public ILconstObject toObject(ILconst val) {
if (val instanceof ILconstObject) {
return (ILconstObject) val;
Expand Down
69 changes: 69 additions & 0 deletions ...cript/src/main/java/de/peeeq/wurstscript/translation/imtranslation/ClosureTranslator.java
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Original file line number Diff line number Diff line change
Expand Up @@ -30,6 +30,7 @@ public class ClosureTranslator {
private Map<ImTypeVar, ImTypeVar> typeVars;
private ImFunction impl;
private ImClass c;
private ImVar capturedThisField;

public ClosureTranslator(ExprClosure e, ImTranslator tr, ImFunction f) {
super();
Expand Down Expand Up @@ -167,6 +168,7 @@ private ImClass createClass() {
} else {
impl.getBody().add(JassIm.ImReturn(e, translated));
}
captureEnclosingThis();
transformTranslated(translated);

typeVars = rewriteTypeVars(c);
Expand Down Expand Up @@ -245,6 +247,9 @@ public ImType case_ImTypeVarRef(ImTypeVarRef t) {
*/
private void transformTranslated(ImExpr t) {
final List<ImVarAccess> vas = Lists.newArrayList();
final List<ImMemberAccess> receiversToRewrite = Lists.newArrayList();
ImVar closureThisVar = tr.getThisVar(e);

t.accept(new ImExpr.DefaultVisitor() {
@Override
public void visit(ImVarAccess va) {
Expand All @@ -254,13 +259,77 @@ public void visit(ImVarAccess va) {
}
}

@Override
public void visit(ImMemberAccess ma) {
super.visit(ma);
if (capturedThisField != null && ma.getReceiver() instanceof ImVarAccess) {
ImVar recvVar = ((ImVarAccess) ma.getReceiver()).getVar();
if (recvVar == closureThisVar && capturesFromEnclosingThis(owningClass(ma.getVar()))) {
receiversToRewrite.add(ma);
}
}
}

});

for (ImVarAccess va : vas) {
ImVar v = getClosureVarFor(va.getVar());
va.replaceBy(JassIm.ImMemberAccess(e, closureThis(), JassIm.ImTypeArguments(), v, JassIm.ImExprs()));
}

for (ImMemberAccess ma : receiversToRewrite) {
ma.setReceiver(JassIm.ImMemberAccess(e, closureThis(), JassIm.ImTypeArguments(), capturedThisField, JassIm.ImExprs()));
}
}

private void captureEnclosingThis() {
ImVar outerThis = getEnclosingThisVar();
if (outerThis != null) {
capturedThisField = getClosureVarFor(outerThis);
}
}

private ImVar getEnclosingThisVar() {
if (f != null && !f.getParameters().isEmpty()) {
ImVar param = f.getParameters().get(0);
if ("this".equals(param.getName()) && param.getType() instanceof ImClassType) {
return param;
}
}
return null;
}

private ImClass owningClass(ImVar var) {
if (var.getParent() != null && var.getParent().getParent() instanceof ImClass) {
return (ImClass) var.getParent().getParent();
}
return null;
}

private boolean capturesFromEnclosingThis(ImClass owner) {
if (owner == null || capturedThisField == null) {
return false;
}
if (!(capturedThisField.getType() instanceof ImClassType)) {
return false;
}

ImClass capturedClass = ((ImClassType) capturedThisField.getType()).getClassDef();
return capturedClass == owner || capturedClass.isSubclassOf(owner);
}

private ImVar findOuterThisVar(ImClass owner) {
// in instance methods, the first parameter is typically "this"
for (ImVar p : f.getParameters()) {
ImType t = p.getType();
if (t instanceof ImClassType) {
ImClassType ct = (ImClassType) t;
if (ct.getClassDef() == owner) {
return p;
}
}
}
return null;
}

private ImVarAccess closureThis() {
Expand Down
83 changes: 83 additions & 0 deletions de.peeeq.wurstscript/src/test/java/tests/wurstscript/tests/GenericsWithTypeclassesTests.java
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Original file line number Diff line number Diff line change
Expand Up @@ -1531,5 +1531,88 @@ public void mixingLegacyOwner_newType_insideGenericClassMethod() {
);
}

@Test
public void arrayListCapacity_lazyClosure_repro() {
testAssertOkLines(true,
"package test",
"",
"native testSuccess()",
"",
"constant int JASS_MAX_ARRAY_SIZE = 8190",
"",
"public function lazy<T:>(Lazy<T> l) returns Lazy<T>",
" return l",
"",
"public abstract class Lazy<T:>",
" T val = null",
" boolean wasRetrieved = false",
"",
" abstract function retrieve() returns T",
"",
" function get() returns T",
" if not wasRetrieved",
" val = retrieve()",
" wasRetrieved = true",
" return val",
"",
"public class ArrayList<T:>",
"",
"public class CFBuilding",
" ArrayList<CFBuilding> upgrades = null",
" Lazy<boolean> hasAAUpgrade = lazy<boolean>(() -> begin",
" var result = false",
" if upgrades != null",
" result = true",
" return result",
" end)",
"",
"",
"init",
" let a = new CFBuilding()",
" let b = new CFBuilding()",
" // ensure upgrades is non-null so closure does some work",
" b.upgrades = new ArrayList<CFBuilding>()",
" // invoke lazy attribute so its closure is actually referenced",
" if b.hasAAUpgrade.get() and not a.hasAAUpgrade.get()",
" testSuccess()"
);
}

@Test
public void inheritedField_lazyClosure_uses_enclosing_receiver() {
testAssertOkLines(true,
"package test",
"",
"native testSuccess()",
"",
"public abstract class Lazy<T:>",
" T val = null",
" boolean wasRetrieved = false",
"",
" abstract function retrieve() returns T",
"",
" function get() returns T",
" if not wasRetrieved",
" val = retrieve()",
" wasRetrieved = true",
" return val",
"",
"public function lazy<T:>(Lazy<T> l) returns Lazy<T>",
" return l",
"",
"public class BaseBuilding",
" boolean hasDetector = true",
"",
"public class AdvancedBuilding extends BaseBuilding",
" Lazy<boolean> detectorAvailable = lazy<boolean>(() -> hasDetector)",
"",
"init",
" let b = new AdvancedBuilding()",
" b.hasDetector = true",
" if b.detectorAvailable.get()",
" testSuccess()"
);
}


}
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