sootup.java.bytecode.interceptors.EmptySwitchEliminator Maven / Gradle / Ivy
package sootup.java.bytecode.interceptors;
/*-
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* Soot - a J*va Optimization Framework
* %%
* Copyright (C) 1997-2020 Raja Vallée-Rai, Christian Brüggemann
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* 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
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*
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* GNU General Lesser Public License for more details.
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*/
import javax.annotation.Nonnull;
import sootup.core.jimple.Jimple;
import sootup.core.jimple.basic.StmtPositionInfo;
import sootup.core.jimple.common.stmt.JGotoStmt;
import sootup.core.jimple.common.stmt.Stmt;
import sootup.core.jimple.javabytecode.stmt.JSwitchStmt;
import sootup.core.model.Body;
import sootup.core.transform.BodyInterceptor;
import sootup.core.views.View;
/**
* Removes empty switch statements which always take the default action from a method body, i.e.
* blocks of the form switch(x) { default: ... }. Such blocks are replaced by the code of the
* default block.
*
* @author Steven Arzt, Zun Wang
*/
public class EmptySwitchEliminator implements BodyInterceptor {
@Override
public void interceptBody(@Nonnull Body.BodyBuilder builder, @Nonnull View view) {
// Iterate all stmts in the body
for (Stmt stmt : builder.getStmtGraph()) {
// If the observed stmt an instance of JSwitchStmt
if (stmt instanceof JSwitchStmt) {
JSwitchStmt sw = (JSwitchStmt) stmt;
// if there's only default case
if (sw.getValueCount() == 1) {
StmtPositionInfo positionInfo = sw.getPositionInfo();
JGotoStmt gotoStmt = Jimple.newGotoStmt(positionInfo);
builder.replaceStmt(sw, gotoStmt);
}
}
}
}
}