diff --git a/evm/src/main/java/org/hyperledger/besu/evm/EVM.java b/evm/src/main/java/org/hyperledger/besu/evm/EVM.java
index f31cec13f09..a77b4ac93a7 100644
--- a/evm/src/main/java/org/hyperledger/besu/evm/EVM.java
+++ b/evm/src/main/java/org/hyperledger/besu/evm/EVM.java
@@ -25,8 +25,8 @@
import org.hyperledger.besu.evm.gascalculator.GasCalculator;
import org.hyperledger.besu.evm.internal.CodeCache;
import org.hyperledger.besu.evm.internal.EvmConfiguration;
-import org.hyperledger.besu.evm.internal.FixedStack.OverflowException;
-import org.hyperledger.besu.evm.internal.FixedStack.UnderflowException;
+import org.hyperledger.besu.evm.internal.OverflowException;
+import org.hyperledger.besu.evm.internal.UnderflowException;
import org.hyperledger.besu.evm.operation.AddModOperation;
import org.hyperledger.besu.evm.operation.AddOperation;
import org.hyperledger.besu.evm.operation.AndOperation;
diff --git a/evm/src/main/java/org/hyperledger/besu/evm/frame/MessageFrame.java b/evm/src/main/java/org/hyperledger/besu/evm/frame/MessageFrame.java
index 64c865dfd41..9eca8d88429 100644
--- a/evm/src/main/java/org/hyperledger/besu/evm/frame/MessageFrame.java
+++ b/evm/src/main/java/org/hyperledger/besu/evm/frame/MessageFrame.java
@@ -26,11 +26,11 @@
import org.hyperledger.besu.datatypes.Wei;
import org.hyperledger.besu.evm.Code;
import org.hyperledger.besu.evm.code.CodeSection;
-import org.hyperledger.besu.evm.internal.FixedStack.UnderflowException;
import org.hyperledger.besu.evm.internal.MemoryEntry;
import org.hyperledger.besu.evm.internal.OperandStack;
import org.hyperledger.besu.evm.internal.ReturnStack;
import org.hyperledger.besu.evm.internal.StorageEntry;
+import org.hyperledger.besu.evm.internal.UnderflowException;
import org.hyperledger.besu.evm.log.Log;
import org.hyperledger.besu.evm.operation.Operation;
import org.hyperledger.besu.evm.worldstate.WorldUpdater;
diff --git a/evm/src/main/java/org/hyperledger/besu/evm/internal/FixedStack.java b/evm/src/main/java/org/hyperledger/besu/evm/internal/FixedStack.java
index c18ee0aeda1..21b913f363c 100644
--- a/evm/src/main/java/org/hyperledger/besu/evm/internal/FixedStack.java
+++ b/evm/src/main/java/org/hyperledger/besu/evm/internal/FixedStack.java
@@ -20,7 +20,8 @@
import java.util.Arrays;
/**
- * An operand stack for the Ethereum Virtual machine (EVM).
+ * An operand stack for the Ethereum Virtual machine (EVM). This stack allocates the entire stack at
+ * initialization time.
*
*
The operand stack is responsible for storing the current operands that the EVM can execute. It
* is assumed to have a fixed size.
@@ -35,30 +36,6 @@ public class FixedStack {
private int top;
- /** The Underflow exception. */
- public static class UnderflowException extends RuntimeException {
- // Don't create a stack trace since these are not "errors" per say but are using exceptions to
- // throw rare control flow conditions (EVM stack overflow) that are expected to be seen in
- // normal
- // operations.
- @Override
- public synchronized Throwable fillInStackTrace() {
- return this;
- }
- }
-
- /** The Overflow exception. */
- public static class OverflowException extends RuntimeException {
- // Don't create a stack trace since these are not "errors" per say but are using exceptions to
- // throw rare control flow conditions (EVM stack overflow) that are expected to be seen in
- // normal
- // operations.
- @Override
- public synchronized Throwable fillInStackTrace() {
- return this;
- }
- }
-
/**
* Instantiates a new Fixed stack.
*
diff --git a/evm/src/main/java/org/hyperledger/besu/evm/internal/FlexStack.java b/evm/src/main/java/org/hyperledger/besu/evm/internal/FlexStack.java
new file mode 100644
index 00000000000..861cfbce8f9
--- /dev/null
+++ b/evm/src/main/java/org/hyperledger/besu/evm/internal/FlexStack.java
@@ -0,0 +1,253 @@
+/*
+ * Copyright contributors to Hyperledger Besu
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+package org.hyperledger.besu.evm.internal;
+
+import static com.google.common.base.Preconditions.checkArgument;
+
+import java.lang.reflect.Array;
+import java.util.Arrays;
+import java.util.Objects;
+
+/**
+ * An operand stack for the Ethereum Virtual machine (EVM). The stack grows 32 entries at a time if
+ * it expands past the top of the allocated stack, up to maxSize.
+ *
+ * The operand stack is responsible for storing the current operands that the EVM can execute. It
+ * is assumed to have a fixed maximum size but may have a smaller memory footprint.
+ *
+ * @param the type parameter
+ */
+public class FlexStack {
+
+ private static final int INCREMENT = 32;
+
+ private T[] entries;
+
+ private final int maxSize;
+ private int currentCapacity;
+
+ private int top;
+
+ /**
+ * Instantiates a new Flex stack.
+ *
+ * @param maxSize the max size
+ * @param klass the klass
+ */
+ @SuppressWarnings("unchecked")
+ public FlexStack(final int maxSize, final Class klass) {
+ checkArgument(maxSize > 0, "max size must be positive");
+
+ this.currentCapacity = Math.min(INCREMENT, maxSize);
+ this.entries = (T[]) Array.newInstance(klass, currentCapacity);
+ this.maxSize = maxSize;
+ this.top = -1;
+ }
+
+ /**
+ * Get operand.
+ *
+ * @param offset the offset
+ * @return the operand
+ */
+ public T get(final int offset) {
+ if (offset < 0 || offset >= size()) {
+ throw new UnderflowException();
+ }
+
+ return entries[top - offset];
+ }
+
+ /**
+ * Pop operand.
+ *
+ * @return the operand
+ */
+ public T pop() {
+ if (top < 0) {
+ throw new UnderflowException();
+ }
+
+ final T removed = entries[top];
+ entries[top--] = null;
+ return removed;
+ }
+
+ /**
+ * Peek and return type T.
+ *
+ * @return the T entry
+ */
+ public T peek() {
+ if (top < 0) {
+ return null;
+ } else {
+ return entries[top];
+ }
+ }
+
+ /**
+ * Pops the specified number of operands from the stack.
+ *
+ * @param items the number of operands to pop off the stack
+ * @throws IllegalArgumentException if the items to pop is negative.
+ * @throws UnderflowException when the items to pop is greater than {@link #size()}
+ */
+ public void bulkPop(final int items) {
+ checkArgument(items > 0, "number of items to pop must be greater than 0");
+ if (items > size()) {
+ throw new UnderflowException();
+ }
+
+ Arrays.fill(entries, top - items + 1, top + 1, null);
+ top -= items;
+ }
+
+ /**
+ * Trims the "middle" section of items out of the stack. Items below the cutpoint remains, and of
+ * the items above only the itemsToKeep items remain. All items in the middle are removed.
+ *
+ * @param cutPoint Point at which to start removing items
+ * @param itemsToKeep itemsToKeep Number of items on top to place at the cutPoint
+ * @throws IllegalArgumentException if the cutPoint or items to keep is negative.
+ * @throws UnderflowException If there are less than itemsToKeep above the cutPoint
+ */
+ public void preserveTop(final int cutPoint, final int itemsToKeep) {
+ checkArgument(cutPoint >= 0, "cutPoint must be positive");
+ checkArgument(itemsToKeep >= 0, "itemsToKeep must be positive");
+ if (itemsToKeep == 0) {
+ if (cutPoint < size()) {
+ bulkPop(top - cutPoint);
+ }
+ } else {
+ int targetSize = cutPoint + itemsToKeep;
+ int currentSize = size();
+ if (targetSize > currentSize) {
+ throw new UnderflowException();
+ } else if (targetSize < currentSize) {
+ System.arraycopy(entries, currentSize - itemsToKeep, entries, cutPoint, itemsToKeep);
+ Arrays.fill(entries, targetSize, currentSize, null);
+ top = targetSize - 1;
+ }
+ }
+ }
+
+ @SuppressWarnings("unchecked")
+ private void expandEntries(final int nextSize) {
+ var nextEntries = (T[]) Array.newInstance(entries.getClass().getComponentType(), nextSize);
+ System.arraycopy(entries, 0, nextEntries, 0, currentCapacity);
+ entries = nextEntries;
+ currentCapacity = nextSize;
+ }
+
+ /**
+ * Push operand.
+ *
+ * @param operand the operand
+ */
+ public void push(final T operand) {
+ final int nextTop = top + 1;
+ if (nextTop >= maxSize) {
+ throw new OverflowException();
+ }
+ if (nextTop >= currentCapacity) {
+ expandEntries(Math.min(currentCapacity + INCREMENT, maxSize));
+ }
+ entries[nextTop] = operand;
+ top = nextTop;
+ }
+
+ /**
+ * Set operand.
+ *
+ * @param offset the offset
+ * @param operand the operand
+ */
+ public void set(final int offset, final T operand) {
+ if (offset < 0) {
+ throw new UnderflowException();
+ } else if (offset > top) {
+ throw new OverflowException();
+ }
+
+ entries[top - offset] = operand;
+ }
+
+ /**
+ * Size of entries.
+ *
+ * @return the size
+ */
+ public int size() {
+ return top + 1;
+ }
+
+ @Override
+ public String toString() {
+ final StringBuilder builder = new StringBuilder();
+ for (int i = 0; i < top; ++i) {
+ builder.append(String.format("%n0x%04X ", i)).append(entries[i]);
+ }
+ return builder.toString();
+ }
+
+ @Override
+ public int hashCode() {
+ int result = 1;
+
+ for (int i = 0; i < currentCapacity; i++) {
+ result = 31 * result + (entries[i] == null ? 0 : entries[i].hashCode());
+ }
+
+ return result;
+ }
+
+ @SuppressWarnings("unchecked")
+ @Override
+ public boolean equals(final Object other) {
+ if (!(other instanceof FlexStack)) {
+ return false;
+ }
+
+ final FlexStack that = (FlexStack) other;
+ if (this.currentCapacity != that.currentCapacity) {
+ return false;
+ }
+ for (int i = 0; i < currentCapacity; i++) {
+ if (!Objects.deepEquals(this.entries[i], that.entries[i])) {
+ return false;
+ }
+ }
+ return true;
+ }
+
+ /**
+ * Is stack full.
+ *
+ * @return the boolean
+ */
+ public boolean isFull() {
+ return top + 1 >= maxSize;
+ }
+
+ /**
+ * Is stack empty.
+ *
+ * @return the boolean
+ */
+ public boolean isEmpty() {
+ return top < 0;
+ }
+}
diff --git a/evm/src/main/java/org/hyperledger/besu/evm/internal/OperandStack.java b/evm/src/main/java/org/hyperledger/besu/evm/internal/OperandStack.java
index 60da0a98343..df27579a297 100644
--- a/evm/src/main/java/org/hyperledger/besu/evm/internal/OperandStack.java
+++ b/evm/src/main/java/org/hyperledger/besu/evm/internal/OperandStack.java
@@ -19,7 +19,7 @@
import org.apache.tuweni.bytes.Bytes;
/** The Operand stack. */
-public class OperandStack extends FixedStack {
+public class OperandStack extends FlexStack {
/**
* Instantiates a new Operand stack.
diff --git a/evm/src/main/java/org/hyperledger/besu/evm/internal/OverflowException.java b/evm/src/main/java/org/hyperledger/besu/evm/internal/OverflowException.java
new file mode 100644
index 00000000000..f2e4efba353
--- /dev/null
+++ b/evm/src/main/java/org/hyperledger/besu/evm/internal/OverflowException.java
@@ -0,0 +1,34 @@
+/*
+ * Copyright contributors to Hyperledger Besu
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+package org.hyperledger.besu.evm.internal;
+
+/**
+ * Overflow exception for {@link FixedStack} and {@link FlexStack}. The main need for a separate
+ * class is to remove the stack trace generation as the exception is not used to signal a debuggable
+ * failure but instead an expected edge case the EVM should handle.
+ */
+public class OverflowException extends RuntimeException {
+
+ /**
+ * Overload the stack trace fill in so no stack is filled in. This is done for performance reasons
+ * as this exception signals an expected corner case not a debuggable failure.
+ *
+ * @return the exception, with no stack trace filled in.
+ */
+ @Override
+ public synchronized Throwable fillInStackTrace() {
+ return this;
+ }
+}
diff --git a/evm/src/main/java/org/hyperledger/besu/evm/internal/ReturnStack.java b/evm/src/main/java/org/hyperledger/besu/evm/internal/ReturnStack.java
index 1482aa704ab..565f9c8cdcf 100644
--- a/evm/src/main/java/org/hyperledger/besu/evm/internal/ReturnStack.java
+++ b/evm/src/main/java/org/hyperledger/besu/evm/internal/ReturnStack.java
@@ -17,7 +17,7 @@
import java.util.Objects;
/** The type Return stack. */
-public class ReturnStack extends FixedStack {
+public class ReturnStack extends FlexStack {
/** The type Return stack item. */
// Java17 convert to record
diff --git a/evm/src/main/java/org/hyperledger/besu/evm/internal/UnderflowException.java b/evm/src/main/java/org/hyperledger/besu/evm/internal/UnderflowException.java
new file mode 100644
index 00000000000..5b794faa6c9
--- /dev/null
+++ b/evm/src/main/java/org/hyperledger/besu/evm/internal/UnderflowException.java
@@ -0,0 +1,34 @@
+/*
+ * Copyright contributors to Hyperledger Besu
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+package org.hyperledger.besu.evm.internal;
+
+/**
+ * Underflow exception for {@link FixedStack} and {@link FlexStack}. The main need for a separate
+ * class is to remove the stack trace generation as the exception is not used to signal a debuggable
+ * failure but instead an expected edge case the EVM should handle.
+ */
+public class UnderflowException extends RuntimeException {
+
+ /**
+ * Overload the stack trace fill in so no stack is filled in. This is done for performance reasons
+ * as this exception signals an expected corner case not a debuggable failure.
+ *
+ * @return the exception, with no stack trace filled in.
+ */
+ @Override
+ public synchronized Throwable fillInStackTrace() {
+ return this;
+ }
+}
diff --git a/evm/src/main/java/org/hyperledger/besu/evm/operation/AbstractFixedCostOperation.java b/evm/src/main/java/org/hyperledger/besu/evm/operation/AbstractFixedCostOperation.java
index afccdb20eb2..30a7b79305e 100644
--- a/evm/src/main/java/org/hyperledger/besu/evm/operation/AbstractFixedCostOperation.java
+++ b/evm/src/main/java/org/hyperledger/besu/evm/operation/AbstractFixedCostOperation.java
@@ -20,8 +20,8 @@
import org.hyperledger.besu.evm.frame.ExceptionalHaltReason;
import org.hyperledger.besu.evm.frame.MessageFrame;
import org.hyperledger.besu.evm.gascalculator.GasCalculator;
-import org.hyperledger.besu.evm.internal.FixedStack.OverflowException;
-import org.hyperledger.besu.evm.internal.FixedStack.UnderflowException;
+import org.hyperledger.besu.evm.internal.OverflowException;
+import org.hyperledger.besu.evm.internal.UnderflowException;
/** The Abstract fixed cost operation. */
abstract class AbstractFixedCostOperation extends AbstractOperation {
diff --git a/evm/src/main/java/org/hyperledger/besu/evm/operation/BalanceOperation.java b/evm/src/main/java/org/hyperledger/besu/evm/operation/BalanceOperation.java
index 3b822d4f887..18538413355 100644
--- a/evm/src/main/java/org/hyperledger/besu/evm/operation/BalanceOperation.java
+++ b/evm/src/main/java/org/hyperledger/besu/evm/operation/BalanceOperation.java
@@ -20,8 +20,8 @@
import org.hyperledger.besu.evm.frame.ExceptionalHaltReason;
import org.hyperledger.besu.evm.frame.MessageFrame;
import org.hyperledger.besu.evm.gascalculator.GasCalculator;
-import org.hyperledger.besu.evm.internal.FixedStack.OverflowException;
-import org.hyperledger.besu.evm.internal.FixedStack.UnderflowException;
+import org.hyperledger.besu.evm.internal.OverflowException;
+import org.hyperledger.besu.evm.internal.UnderflowException;
import org.hyperledger.besu.evm.internal.Words;
import org.apache.tuweni.bytes.Bytes;
diff --git a/evm/src/main/java/org/hyperledger/besu/evm/operation/ExtCodeHashOperation.java b/evm/src/main/java/org/hyperledger/besu/evm/operation/ExtCodeHashOperation.java
index 5ab9216903f..ba6cd22d9df 100644
--- a/evm/src/main/java/org/hyperledger/besu/evm/operation/ExtCodeHashOperation.java
+++ b/evm/src/main/java/org/hyperledger/besu/evm/operation/ExtCodeHashOperation.java
@@ -20,8 +20,8 @@
import org.hyperledger.besu.evm.frame.ExceptionalHaltReason;
import org.hyperledger.besu.evm.frame.MessageFrame;
import org.hyperledger.besu.evm.gascalculator.GasCalculator;
-import org.hyperledger.besu.evm.internal.FixedStack.OverflowException;
-import org.hyperledger.besu.evm.internal.FixedStack.UnderflowException;
+import org.hyperledger.besu.evm.internal.OverflowException;
+import org.hyperledger.besu.evm.internal.UnderflowException;
import org.hyperledger.besu.evm.internal.Words;
import org.apache.tuweni.bytes.Bytes;
diff --git a/evm/src/main/java/org/hyperledger/besu/evm/operation/ExtCodeSizeOperation.java b/evm/src/main/java/org/hyperledger/besu/evm/operation/ExtCodeSizeOperation.java
index 6ab0f799dc7..9d891f7d37e 100644
--- a/evm/src/main/java/org/hyperledger/besu/evm/operation/ExtCodeSizeOperation.java
+++ b/evm/src/main/java/org/hyperledger/besu/evm/operation/ExtCodeSizeOperation.java
@@ -20,8 +20,8 @@
import org.hyperledger.besu.evm.frame.ExceptionalHaltReason;
import org.hyperledger.besu.evm.frame.MessageFrame;
import org.hyperledger.besu.evm.gascalculator.GasCalculator;
-import org.hyperledger.besu.evm.internal.FixedStack.OverflowException;
-import org.hyperledger.besu.evm.internal.FixedStack.UnderflowException;
+import org.hyperledger.besu.evm.internal.OverflowException;
+import org.hyperledger.besu.evm.internal.UnderflowException;
import org.hyperledger.besu.evm.internal.Words;
import org.apache.tuweni.bytes.Bytes;
diff --git a/evm/src/main/java/org/hyperledger/besu/evm/operation/SLoadOperation.java b/evm/src/main/java/org/hyperledger/besu/evm/operation/SLoadOperation.java
index 087d18ab0ee..f97917a9935 100644
--- a/evm/src/main/java/org/hyperledger/besu/evm/operation/SLoadOperation.java
+++ b/evm/src/main/java/org/hyperledger/besu/evm/operation/SLoadOperation.java
@@ -20,8 +20,8 @@
import org.hyperledger.besu.evm.frame.ExceptionalHaltReason;
import org.hyperledger.besu.evm.frame.MessageFrame;
import org.hyperledger.besu.evm.gascalculator.GasCalculator;
-import org.hyperledger.besu.evm.internal.FixedStack.OverflowException;
-import org.hyperledger.besu.evm.internal.FixedStack.UnderflowException;
+import org.hyperledger.besu.evm.internal.OverflowException;
+import org.hyperledger.besu.evm.internal.UnderflowException;
import org.apache.tuweni.bytes.Bytes32;
import org.apache.tuweni.units.bigints.UInt256;
diff --git a/evm/src/main/java/org/hyperledger/besu/evm/operation/TLoadOperation.java b/evm/src/main/java/org/hyperledger/besu/evm/operation/TLoadOperation.java
index e813e72e1a9..7187e5d12b1 100644
--- a/evm/src/main/java/org/hyperledger/besu/evm/operation/TLoadOperation.java
+++ b/evm/src/main/java/org/hyperledger/besu/evm/operation/TLoadOperation.java
@@ -18,8 +18,8 @@
import org.hyperledger.besu.evm.frame.ExceptionalHaltReason;
import org.hyperledger.besu.evm.frame.MessageFrame;
import org.hyperledger.besu.evm.gascalculator.GasCalculator;
-import org.hyperledger.besu.evm.internal.FixedStack.OverflowException;
-import org.hyperledger.besu.evm.internal.FixedStack.UnderflowException;
+import org.hyperledger.besu.evm.internal.OverflowException;
+import org.hyperledger.besu.evm.internal.UnderflowException;
import org.apache.tuweni.bytes.Bytes32;
import org.apache.tuweni.units.bigints.UInt256;
diff --git a/evm/src/test/java/org/hyperledger/besu/evm/internal/OperandStackTest.java b/evm/src/test/java/org/hyperledger/besu/evm/internal/OperandStackTest.java
index 63afa470584..9a3e21f134e 100644
--- a/evm/src/test/java/org/hyperledger/besu/evm/internal/OperandStackTest.java
+++ b/evm/src/test/java/org/hyperledger/besu/evm/internal/OperandStackTest.java
@@ -17,12 +17,11 @@
import static org.assertj.core.api.Assertions.assertThat;
import static org.assertj.core.api.Assertions.assertThatThrownBy;
-import org.hyperledger.besu.evm.internal.FixedStack.OverflowException;
-import org.hyperledger.besu.evm.internal.FixedStack.UnderflowException;
-
import org.apache.tuweni.bytes.Bytes32;
import org.apache.tuweni.units.bigints.UInt256;
import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
class OperandStackTest {
@@ -99,6 +98,14 @@ void set_IndexGreaterThanSize() {
assertThatThrownBy(() -> stack.set(2, operand)).isInstanceOf(OverflowException.class);
}
+ @Test
+ void set_IndexGreaterThanCurrentSize() {
+ final OperandStack stack = new OperandStack(1024);
+ stack.push(UInt256.fromHexString("0x01"));
+ final Bytes32 operand = Bytes32.fromHexString("0x01");
+ assertThatThrownBy(() -> stack.set(2, operand)).isInstanceOf(OverflowException.class);
+ }
+
@Test
void set() {
final OperandStack stack = new OperandStack(3);
@@ -165,4 +172,14 @@ void preserveTop() {
assertThatThrownBy(() -> stack.preserveTop(5, 1)).isInstanceOf(UnderflowException.class);
assertThatThrownBy(() -> stack.preserveTop(1, 5)).isInstanceOf(UnderflowException.class);
}
+
+ @ParameterizedTest
+ @ValueSource(ints = {5, 31, 32, 33, 1023, 1024, 1025})
+ void largeOverflows(final int n) {
+ final OperandStack stack = new OperandStack(n);
+ for (int i = 0; i < n; i++) {
+ stack.push(UInt256.ONE);
+ }
+ assertThatThrownBy(() -> stack.push(UInt256.ONE)).isInstanceOf(OverflowException.class);
+ }
}