Mercurial > hg > Members > kono > jpf-core
view src/main/gov/nasa/jpf/jvm/bytecode/SwitchInstruction.java @ 27:8aded593a50f
fixed the missing class init status update for native clinits. Since we moved
that to the clinit RETURN in r24, it has to be duplicated in NATIVERETURN for native
clinits. Factoring out to DIRECTCALLRETURN is not an option since there is no
good way to determine if the direct call included a clinit (we would have to
look at the code, which is suboptimal performance- and change resilience-wise).
Thanks to Franz Weitl for the report
author | Peter Mehlitz <pcmehlitz@gmail.com> |
---|---|
date | Mon, 11 May 2015 12:17:18 -0700 |
parents | 61d41facf527 |
children |
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/* * Copyright (C) 2014, United States Government, as represented by the * Administrator of the National Aeronautics and Space Administration. * All rights reserved. * * The Java Pathfinder core (jpf-core) platform is 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. */ package gov.nasa.jpf.jvm.bytecode; import gov.nasa.jpf.vm.Instruction; import gov.nasa.jpf.vm.KernelState; import gov.nasa.jpf.vm.StackFrame; import gov.nasa.jpf.vm.SystemState; import gov.nasa.jpf.vm.ThreadInfo; import gov.nasa.jpf.vm.choice.IntIntervalGenerator; /** * common root class for LOOKUPSWITCH and TABLESWITCH insns * * <2do> this is inefficient. First, we should store targets as instruction indexes * to avoid execution() looping. Second, there are no matches for a TABLESWITCH */ public abstract class SwitchInstruction extends Instruction implements JVMInstruction { public static final int DEFAULT = -1; protected int target; // default branch protected int[] targets; // explicit value branches protected int[] matches; // branch consts protected int lastIdx; protected SwitchInstruction (int defaultTarget, int numberOfTargets){ target = defaultTarget; targets = new int[numberOfTargets]; matches = new int[numberOfTargets]; } public int getNumberOfEntries() { return targets.length; } protected Instruction executeConditional (ThreadInfo ti){ StackFrame frame = ti.getModifiableTopFrame(); int value = frame.pop(); lastIdx = DEFAULT; for (int i = 0, l = matches.length; i < l; i++) { if (value == matches[i]) { lastIdx = i; return mi.getInstructionAt(targets[i]); } } return mi.getInstructionAt(target); } @Override public Instruction execute (ThreadInfo ti) { // this can be overridden by subclasses, so we have to delegate the conditional execution // to avoid getting recursive in executeAllBranches() return executeConditional(ti); } /** useful for symbolic execution modes */ public Instruction executeAllBranches (SystemState ss, KernelState ks, ThreadInfo ti) { if (!ti.isFirstStepInsn()) { IntIntervalGenerator cg = new IntIntervalGenerator("switchAll", 0,matches.length); if (ss.setNextChoiceGenerator(cg)){ return this; } else { // listener did override CG, fall back to conditional execution return executeConditional(ti); } } else { IntIntervalGenerator cg = ss.getCurrentChoiceGenerator("switchAll", IntIntervalGenerator.class); assert (cg != null) : "no IntIntervalGenerator"; StackFrame frame = ti.getModifiableTopFrame(); int idx = frame.pop(); // but we are not using it idx = cg.getNextChoice(); if (idx == matches.length){ // default branch lastIdx = DEFAULT; return mi.getInstructionAt(target); } else { lastIdx = idx; return mi.getInstructionAt(targets[idx]); } } } //--- a little inspection, but only post exec yet public int getLastTargetIndex () { return lastIdx; } public int getNumberOfTargets () { return matches.length; } public int getMatchConst (int idx){ return matches[idx]; } @Override public void accept(JVMInstructionVisitor insVisitor) { insVisitor.visit(this); } public int getTarget() { return target; } public int[] getTargets() { return targets; } public int[] getMatches() { return matches; } }