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Merged
fglock merged 1 commit into from
Feb 4, 2026
Merged

cleanup - stack tracking is no longer used #160

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1 change: 0 additions & 1 deletion src/main/java/org/perlonjava/codegen/EmitBlock.java
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Original file line number Diff line number Diff line change
Expand Up @@ -144,7 +144,6 @@ public static void emitBlock(EmitterVisitor emitterVisitor, BlockNode node) {
nextLabel,
redoLabel,
nextLabel,
emitterVisitor.ctx.javaClassInfo.stackLevelManager.getStackLevel(),
emitterVisitor.ctx.contextType,
isBareBlock,
isBareBlock);
Expand Down
22 changes: 2 additions & 20 deletions src/main/java/org/perlonjava/codegen/EmitControlFlow.java
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Expand Up @@ -107,12 +107,6 @@ static void handleNextOperator(EmitterContext ctx, OperatorNode node) {
return;
}

// Local control flow: use fast GOTO (existing code)
ctx.logDebug("visit(next): asmStackLevel: " + ctx.javaClassInfo.stackLevelManager.getStackLevel());

// Clean up the stack before jumping by popping values up to the loop's stack level
ctx.javaClassInfo.resetStackLevel();

// Handle return values based on context
if (loopLabels.context != RuntimeContextType.VOID) {
if (operator.equals("next") || operator.equals("last")) {
Expand Down Expand Up @@ -167,9 +161,6 @@ static void handleReturnOperator(EmitterVisitor emitterVisitor, OperatorNode nod
}
}

// Clean up tracked stack before return
ctx.javaClassInfo.resetStackLevel();

boolean hasOperand = !(node.operand == null || (node.operand instanceof ListNode list && list.elements.isEmpty()));

if (!hasOperand) {
Expand Down Expand Up @@ -204,9 +195,6 @@ static void handleGotoSubroutine(EmitterVisitor emitterVisitor, OperatorNode sub

ctx.logDebug("visit(goto &sub): Emitting TAILCALL marker");

// Clean up tracked stack before creating the marker
ctx.javaClassInfo.resetStackLevel();

subNode.accept(emitterVisitor.with(RuntimeContextType.SCALAR));
int codeRefSlot = ctx.javaClassInfo.acquireSpillSlot();
boolean pooledCodeRef = codeRefSlot >= 0;
Expand Down Expand Up @@ -332,8 +320,6 @@ static void handleGotoLabel(EmitterVisitor emitterVisitor, OperatorNode node) {
"(Lorg/perlonjava/runtime/RuntimeScalar;Lorg/perlonjava/runtime/RuntimeArray;Ljava/lang/String;I)V",
false);

ctx.javaClassInfo.resetStackLevel(); // Clean up stack before jumping

if (pooledTarget) {
ctx.javaClassInfo.releaseSpillSlot();
}
Expand Down Expand Up @@ -388,8 +374,7 @@ static void handleGotoLabel(EmitterVisitor emitterVisitor, OperatorNode node) {
}
ctx.mv.visitVarInsn(Opcodes.ASTORE, markerSlot);

// Clean stack and jump to returnLabel with the marker on stack.
ctx.javaClassInfo.resetStackLevel();
// Jump to returnLabel with the marker on stack.
ctx.mv.visitVarInsn(Opcodes.ALOAD, markerSlot);
if (pooledMarker) {
ctx.javaClassInfo.releaseSpillSlot();
Expand Down Expand Up @@ -437,8 +422,7 @@ static void handleGotoLabel(EmitterVisitor emitterVisitor, OperatorNode node) {
}
ctx.mv.visitVarInsn(Opcodes.ASTORE, markerSlot);

// Clean stack and jump to returnLabel with the marker on stack.
ctx.javaClassInfo.resetStackLevel();
// Jump to returnLabel with the marker on stack.
ctx.mv.visitVarInsn(Opcodes.ALOAD, markerSlot);
if (pooledMarker) {
ctx.javaClassInfo.releaseSpillSlot();
Expand All @@ -449,8 +433,6 @@ static void handleGotoLabel(EmitterVisitor emitterVisitor, OperatorNode node) {
}

// Local goto: use fast GOTO (existing code)
// Clean up stack before jumping to maintain stack consistency
ctx.javaClassInfo.resetStackLevel();

// Emit the goto instruction
ctx.mv.visitJumpInsn(Opcodes.GOTO, targetLabel.gotoLabel);
Expand Down
1 change: 0 additions & 1 deletion src/main/java/org/perlonjava/codegen/EmitForeach.java
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Expand Up @@ -302,7 +302,6 @@ public static void emitFor1(EmitterVisitor emitterVisitor, For1Node node) {
continueLabel,
redoLabel,
loopEnd,
emitterVisitor.ctx.javaClassInfo.stackLevelManager.getStackLevel(),
RuntimeContextType.VOID);
currentLoopLabels.controlFlowHandler = controlFlowHandler;

Expand Down
7 changes: 0 additions & 7 deletions src/main/java/org/perlonjava/codegen/EmitLogicalOperator.java
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Expand Up @@ -281,17 +281,10 @@ private static void emitLogicalOperatorSimple(EmitterVisitor emitterVisitor, Bin
mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "org/perlonjava/runtime/RuntimeBase", getBoolean, "()Z", false);
mv.visitJumpInsn(compareOpcode, endLabel);

// The condition value has been consumed by getBoolean() and the conditional jump.
// Keep StackLevelManager in sync with the actual operand stack (empty) so that
// downstream non-local control flow (return/last/next/redo/goto) doesn't emit POPs
// based on stale stack accounting.
emitterVisitor.ctx.javaClassInfo.resetStackLevel();

node.right.accept(emitterVisitor.with(RuntimeContextType.SCALAR));
mv.visitInsn(Opcodes.POP);

mv.visitLabel(endLabel);
emitterVisitor.ctx.javaClassInfo.resetStackLevel();
return;
}

Expand Down
3 changes: 0 additions & 3 deletions src/main/java/org/perlonjava/codegen/EmitStatement.java
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Expand Up @@ -164,7 +164,6 @@ public static void emitFor3(EmitterVisitor emitterVisitor, For3Node node) {
continueLabel,
redoLabel,
endLabel,
emitterVisitor.ctx.javaClassInfo.stackLevelManager.getStackLevel(),
RuntimeContextType.VOID,
true,
isUnlabeledTarget);
Expand Down Expand Up @@ -245,7 +244,6 @@ static void emitDoWhile(EmitterVisitor emitterVisitor, For3Node node) {
continueLabel,
redoLabel,
endLabel,
emitterVisitor.ctx.javaClassInfo.stackLevelManager.getStackLevel(),
RuntimeContextType.VOID,
false); // isTrueLoop = false (do-while is not a true loop)

Expand All @@ -266,7 +264,6 @@ static void emitDoWhile(EmitterVisitor emitterVisitor, For3Node node) {
continueLabel,
redoLabel,
endLabel,
emitterVisitor.ctx.javaClassInfo.stackLevelManager.getStackLevel(),
RuntimeContextType.VOID,
false);
emitRegistryCheck(mv, loopLabels, redoLabel, continueLabel, endLabel);
Expand Down
11 changes: 1 addition & 10 deletions src/main/java/org/perlonjava/codegen/EmitSubroutine.java
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Expand Up @@ -379,8 +379,7 @@ static void handleApplyOperator(EmitterVisitor emitterVisitor, BinaryOperatorNod
// If RuntimeCode.apply() returned a RuntimeControlFlowList marker, handle it here.
if (ENABLE_CONTROL_FLOW_CHECKS
&& emitterVisitor.ctx.javaClassInfo.returnLabel != null
&& emitterVisitor.ctx.javaClassInfo.controlFlowTempSlot >= 0
&& emitterVisitor.ctx.javaClassInfo.stackLevelManager.getStackLevel() <= 1) {
&& emitterVisitor.ctx.javaClassInfo.controlFlowTempSlot >= 0) {

Label notControlFlow = new Label();
Label propagateToCaller = new Label();
Expand All @@ -399,11 +398,6 @@ static void handleApplyOperator(EmitterVisitor emitterVisitor, BinaryOperatorNod
emitterVisitor.ctx.javaClassInfo.storeSpillRef(mv, baseSpills[i]);
}

// We just removed the entire base stack from the JVM operand stack via ASTORE.
// Keep StackLevelManager in sync; otherwise later emitPopInstructions() may POP the wrong values
// (including control-flow markers), producing invalid stackmap frames.
emitterVisitor.ctx.javaClassInfo.resetStackLevel();

// Load and check if it's a control flow marker
mv.visitVarInsn(Opcodes.ALOAD, emitterVisitor.ctx.javaClassInfo.controlFlowTempSlot);
mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL,
Expand Down Expand Up @@ -463,7 +457,6 @@ static void handleApplyOperator(EmitterVisitor emitterVisitor, BinaryOperatorNod
if (loopLabels.lastLabel == emitterVisitor.ctx.javaClassInfo.returnLabel) {
mv.visitJumpInsn(Opcodes.GOTO, propagateToCaller);
} else {
emitterVisitor.ctx.javaClassInfo.stackLevelManager.emitPopInstructions(mv, loopLabels.asmStackLevel);
if (loopLabels.context != RuntimeContextType.VOID) {
EmitOperator.emitUndef(mv);
}
Expand All @@ -478,7 +471,6 @@ static void handleApplyOperator(EmitterVisitor emitterVisitor, BinaryOperatorNod
if (loopLabels.nextLabel == emitterVisitor.ctx.javaClassInfo.returnLabel) {
mv.visitJumpInsn(Opcodes.GOTO, propagateToCaller);
} else {
emitterVisitor.ctx.javaClassInfo.stackLevelManager.emitPopInstructions(mv, loopLabels.asmStackLevel);
if (loopLabels.context != RuntimeContextType.VOID) {
EmitOperator.emitUndef(mv);
}
Expand All @@ -490,7 +482,6 @@ static void handleApplyOperator(EmitterVisitor emitterVisitor, BinaryOperatorNod
if (loopLabels.redoLabel == emitterVisitor.ctx.javaClassInfo.returnLabel) {
mv.visitJumpInsn(Opcodes.GOTO, propagateToCaller);
} else {
emitterVisitor.ctx.javaClassInfo.stackLevelManager.emitPopInstructions(mv, loopLabels.asmStackLevel);
mv.visitJumpInsn(Opcodes.GOTO, loopLabels.redoLabel);
}

Expand Down
10 changes: 1 addition & 9 deletions src/main/java/org/perlonjava/codegen/GotoLabels.java
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Expand Up @@ -17,22 +17,15 @@ public class GotoLabels {
*/
public Label gotoLabel;

/**
* The stack level at the point where this label is defined
*/
public int asmStackLevel;

/**
* Creates a new GotoLabels instance.
*
* @param labelName The name of the label in source code
* @param gotoLabel The ASM Label object for bytecode generation
* @param asmStackLevel The stack level at label definition
*/
public GotoLabels(String labelName, Label gotoLabel, int asmStackLevel) {
public GotoLabels(String labelName, Label gotoLabel) {
this.labelName = labelName;
this.gotoLabel = gotoLabel;
this.asmStackLevel = asmStackLevel;
}

/**
Expand All @@ -46,7 +39,6 @@ public String toString() {
return "GotoLabels{" +
"labelName='" + labelName + '\'' +
", gotoLabel=" + gotoLabel +
", asmStackLevel=" + asmStackLevel +
'}';
}
}
27 changes: 6 additions & 21 deletions src/main/java/org/perlonjava/codegen/JavaClassInfo.java
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Expand Up @@ -64,11 +64,6 @@ public SpillRef(int slot, boolean pooled) {
}
}

/**
* Manages the stack level for the class.
*/
public StackLevelManager stackLevelManager;

/**
* A stack of loop labels for managing nested loops.
*/
Expand All @@ -84,7 +79,6 @@ public JavaClassInfo() {
this.javaClassName = EmitterMethodCreator.generateClassName();
this.returnLabel = null;
this.returnValueSlot = -1;
this.stackLevelManager = new StackLevelManager();
this.loopLabelStack = new ArrayDeque<>();
this.gotoLabelStack = new ArrayDeque<>();
this.spillSlots = new int[0];
Expand Down Expand Up @@ -143,7 +137,7 @@ public void releaseSpillRef(SpillRef ref) {
* @param lastLabel the label for exiting the loop
*/
public void pushLoopLabels(String labelName, Label nextLabel, Label redoLabel, Label lastLabel, int context) {
loopLabelStack.push(new LoopLabels(labelName, nextLabel, redoLabel, lastLabel, stackLevelManager.getStackLevel(), context));
loopLabelStack.push(new LoopLabels(labelName, nextLabel, redoLabel, lastLabel, context));
}

/**
Expand All @@ -153,16 +147,15 @@ public void pushLoopLabels(String labelName, Label nextLabel, Label redoLabel, L
* @param nextLabel the label for the next iteration
* @param redoLabel the label for redoing the current iteration
* @param lastLabel the label for exiting the loop
* @param stackLevel the current stack level
* @param context the context type
* @param isTrueLoop whether this is a true loop (for/while/until) or pseudo-loop (do-while/bare)
*/
public void pushLoopLabels(String labelName, Label nextLabel, Label redoLabel, Label lastLabel, int stackLevel, int context, boolean isTrueLoop) {
loopLabelStack.push(new LoopLabels(labelName, nextLabel, redoLabel, lastLabel, stackLevel, context, isTrueLoop));
public void pushLoopLabels(String labelName, Label nextLabel, Label redoLabel, Label lastLabel, int context, boolean isTrueLoop) {
loopLabelStack.push(new LoopLabels(labelName, nextLabel, redoLabel, lastLabel, context, isTrueLoop));
}

public void pushLoopLabels(String labelName, Label nextLabel, Label redoLabel, Label lastLabel, int stackLevel, int context, boolean isTrueLoop, boolean isUnlabeledControlFlowTarget) {
loopLabelStack.push(new LoopLabels(labelName, nextLabel, redoLabel, lastLabel, stackLevel, context, isTrueLoop, isUnlabeledControlFlowTarget));
public void pushLoopLabels(String labelName, Label nextLabel, Label redoLabel, Label lastLabel, int context, boolean isTrueLoop, boolean isUnlabeledControlFlowTarget) {
loopLabelStack.push(new LoopLabels(labelName, nextLabel, redoLabel, lastLabel, context, isTrueLoop, isUnlabeledControlFlowTarget));
}

/**
Expand Down Expand Up @@ -242,7 +235,7 @@ public LoopLabels findInnermostTrueLoopLabels() {
}

public void pushGotoLabels(String labelName, Label gotoLabel) {
gotoLabelStack.push(new GotoLabels(labelName, gotoLabel, stackLevelManager.getStackLevel()));
gotoLabelStack.push(new GotoLabels(labelName, gotoLabel));
}

public GotoLabels findGotoLabelsByName(String labelName) {
Expand All @@ -258,13 +251,6 @@ public void popGotoLabels() {
gotoLabelStack.pop();
}

/**
* Resets the stack level to its initial state.
*/
public void resetStackLevel() {
stackLevelManager.reset();
}

/**
* Returns a string representation of the JavaClassInfo object.
*
Expand All @@ -275,7 +261,6 @@ public String toString() {
return "JavaClassInfo{\n" +
" javaClassName='" + javaClassName + "',\n" +
" returnLabel=" + (returnLabel != null ? returnLabel.toString() : "null") + ",\n" +
" asmStackLevel=" + stackLevelManager.getStackLevel() + ",\n" +
" loopLabelStack=" + loopLabelStack + "\n" +
" gotoLabelStack=" + gotoLabelStack + "\n" +
"}";
Expand Down
19 changes: 5 additions & 14 deletions src/main/java/org/perlonjava/codegen/LoopLabels.java
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Expand Up @@ -40,11 +40,6 @@ public class LoopLabels {
*/
public int context;

/**
* The stack level at the point where these loop labels are defined
*/
public int asmStackLevel;

/**
* Whether this is a "true" loop (for/while/until) vs a pseudo-loop (do-while/bare block).
* True loops allow last/next/redo. Pseudo-loops cause compile errors.
Expand All @@ -70,11 +65,10 @@ public class LoopLabels {
* @param nextLabel The ASM Label for 'next' operations
* @param redoLabel The ASM Label for 'redo' operations
* @param lastLabel The ASM Label for 'last' operations
* @param asmStackLevel The stack level at label definition
* @param context The context type for this loop
*/
public LoopLabels(String labelName, Label nextLabel, Label redoLabel, Label lastLabel, int asmStackLevel, int context) {
this(labelName, nextLabel, redoLabel, lastLabel, asmStackLevel, context, true, true);
public LoopLabels(String labelName, Label nextLabel, Label redoLabel, Label lastLabel, int context) {
this(labelName, nextLabel, redoLabel, lastLabel, context, true, true);
}

/**
Expand All @@ -84,20 +78,18 @@ public LoopLabels(String labelName, Label nextLabel, Label redoLabel, Label last
* @param nextLabel The ASM Label for 'next' operations
* @param redoLabel The ASM Label for 'redo' operations
* @param lastLabel The ASM Label for 'last' operations
* @param asmStackLevel The stack level at label definition
* @param context The context type for this loop
* @param isTrueLoop Whether this is a true loop (for/while/until) or pseudo-loop (do-while/bare)
*/
public LoopLabels(String labelName, Label nextLabel, Label redoLabel, Label lastLabel, int asmStackLevel, int context, boolean isTrueLoop) {
this(labelName, nextLabel, redoLabel, lastLabel, asmStackLevel, context, isTrueLoop, true);
public LoopLabels(String labelName, Label nextLabel, Label redoLabel, Label lastLabel, int context, boolean isTrueLoop) {
this(labelName, nextLabel, redoLabel, lastLabel, context, isTrueLoop, true);
}

public LoopLabels(String labelName, Label nextLabel, Label redoLabel, Label lastLabel, int asmStackLevel, int context, boolean isTrueLoop, boolean isUnlabeledControlFlowTarget) {
public LoopLabels(String labelName, Label nextLabel, Label redoLabel, Label lastLabel, int context, boolean isTrueLoop, boolean isUnlabeledControlFlowTarget) {
this.labelName = labelName;
this.nextLabel = nextLabel;
this.redoLabel = redoLabel;
this.lastLabel = lastLabel;
this.asmStackLevel = asmStackLevel;
this.context = context;
this.isTrueLoop = isTrueLoop;
this.isUnlabeledControlFlowTarget = isUnlabeledControlFlowTarget;
Expand All @@ -116,7 +108,6 @@ public String toString() {
", nextLabel=" + nextLabel +
", redoLabel=" + redoLabel +
", lastLabel=" + lastLabel +
", asmStackLevel=" + asmStackLevel +
", context=" + context +
'}';
}
Expand Down
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