soot.coffi.TypeStack Maven / Gradle / Ivy
package soot.coffi;
/*-
* #%L
* Soot - a J*va Optimization Framework
* %%
* Copyright (C) 1997 Clark Verbrugge
* %%
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation, either version 2.1 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Lesser Public License for more details.
*
* You should have received a copy of the GNU General Lesser Public
* License along with this program. If not, see
* .
* #L%
*/
import java.io.PrintStream;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import soot.ArrayType;
import soot.RefType;
import soot.Type;
/*
* A less resource hungry implementation of the TypeStack would just have pointers to
* 'sub-stacks' instead of copying the entire array around.
*/
class TypeStack {
private static final Logger logger = LoggerFactory.getLogger(TypeStack.class);
private Type[] types;
private TypeStack() {
// no constructor
}
public Object clone() {
TypeStack newTypeStack = new TypeStack();
newTypeStack.types = types.clone();
return newTypeStack;
}
/**
* Returns an empty stack.
*/
public static TypeStack v() {
TypeStack typeStack = new TypeStack();
typeStack.types = new Type[0];
return typeStack;
}
public TypeStack pop() {
TypeStack newStack = new TypeStack();
newStack.types = new Type[types.length - 1];
System.arraycopy(types, 0, newStack.types, 0, types.length - 1);
return newStack;
}
public TypeStack push(Type type) {
TypeStack newStack = new TypeStack();
newStack.types = new Type[types.length + 1];
System.arraycopy(types, 0, newStack.types, 0, types.length);
newStack.types[types.length] = type;
return newStack;
}
public Type get(int index) {
return types[index];
}
public int topIndex() {
return types.length - 1;
}
public Type top() {
if (types.length == 0) {
throw new RuntimeException("TypeStack is empty");
} else {
return types[types.length - 1];
}
}
public boolean equals(Object object) {
if (object instanceof TypeStack) {
TypeStack otherStack = (TypeStack) object;
if (otherStack.types.length != types.length) {
return false;
}
for (Type element : types) {
if (!element.equals(element)) {
return false;
}
}
return true;
} else {
return false;
}
}
public TypeStack merge(TypeStack other) {
if (types.length != other.types.length) {
throw new RuntimeException(
"TypeStack merging failed; unequal " + "stack lengths: " + types.length + " and " + other.types.length);
}
TypeStack newStack = new TypeStack();
newStack.types = new Type[other.types.length];
for (int i = 0; i < types.length; i++) {
if (types[i].equals(other.types[i])) {
newStack.types[i] = types[i];
} else {
if ((!(types[i] instanceof ArrayType) && !(types[i] instanceof RefType))
|| (!(other.types[i] instanceof RefType) && !(other.types[i] instanceof ArrayType))) {
throw new RuntimeException("TypeStack merging failed; incompatible types " + types[i] + " and " + other.types[i]);
}
// logger.debug("Merging: " + types[i] + " with " + other.types[i]);
newStack.types[i] = RefType.v("java.lang.Object");
}
}
return newStack;
}
public void print(PrintStream out) {
for (int i = types.length - 1; i >= 0; i--) {
out.println(i + ": " + types[i].toString());
}
if (types.length == 0) {
out.println("");
}
}
}