/*
* Copyright 2000-2015 JetBrains s.r.o.
*
* 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 com.intellij.codeInspection.bytecodeAnalysis.asm;
import org.jetbrains.org.objectweb.asm.Type;
import org.jetbrains.org.objectweb.asm.tree.*;
import org.jetbrains.org.objectweb.asm.tree.analysis.*;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* Extended version of {@link org.jetbrains.org.objectweb.asm.tree.analysis.Analyzer}.
* It handles frames <b>and</b> additional data.
*
* @author lambdamix
*/
public class AnalyzerExt<V extends Value, Data, MyInterpreter extends Interpreter<V> & InterpreterExt<Data>> extends SubroutineFinder {
private final MyInterpreter interpreter;
private Frame<V>[] frames;
private boolean[] queued;
private int[] queue;
private int top;
public Data[] getData() {
return data;
}
private final Data[] data;
public AnalyzerExt(final MyInterpreter interpreter, Data[] data, Data startData) {
this.interpreter = interpreter;
this.data = data;
if (data.length > 0) {
data[0] = startData;
}
}
public Frame<V>[] analyze(final String owner, final MethodNode m) throws AnalyzerException {
if ((m.access & (ACC_ABSTRACT | ACC_NATIVE)) != 0) {
frames = (Frame<V>[]) new Frame<?>[0];
return frames;
}
final V refV = (V) BasicValue.REFERENCE_VALUE;
n = m.instructions.size();
insns = m.instructions;
handlers = (List<TryCatchBlockNode>[]) new List<?>[n];
frames = (Frame<V>[]) new Frame<?>[n];
subroutines = new Subroutine[n];
queued = new boolean[n];
queue = new int[n];
top = 0;
// computes exception handlers for each instruction
for (int i = 0; i < m.tryCatchBlocks.size(); ++i) {
TryCatchBlockNode tcb = m.tryCatchBlocks.get(i);
int begin = insns.indexOf(tcb.start);
int end = insns.indexOf(tcb.end);
for (int j = begin; j < end; ++j) {
List<TryCatchBlockNode> insnHandlers = handlers[j];
if (insnHandlers == null) {
insnHandlers = new ArrayList<>();
handlers[j] = insnHandlers;
}
insnHandlers.add(tcb);
}
}
// computes the subroutine for each instruction:
Subroutine main = new Subroutine(null, m.maxLocals, null);
List<AbstractInsnNode> subroutineCalls = new ArrayList<>();
Map<LabelNode, Subroutine> subroutineHeads = new HashMap<>();
findSubroutine(0, main, subroutineCalls);
while (!subroutineCalls.isEmpty()) {
JumpInsnNode jsr = (JumpInsnNode) subroutineCalls.remove(0);
Subroutine sub = subroutineHeads.get(jsr.label);
if (sub == null) {
sub = new Subroutine(jsr.label, m.maxLocals, jsr);
subroutineHeads.put(jsr.label, sub);
findSubroutine(insns.indexOf(jsr.label), sub, subroutineCalls);
} else {
sub.callers.add(jsr);
}
}
for (int i = 0; i < n; ++i) {
if (subroutines[i] != null && subroutines[i].start == null) {
subroutines[i] = null;
}
}
// initializes the data structures for the control flow analysis
Frame<V> current = newFrame(m.maxLocals, m.maxStack);
Frame<V> handler = newFrame(m.maxLocals, m.maxStack);
current.setReturn(interpreter.newValue(Type.getReturnType(m.desc)));
Type[] args = Type.getArgumentTypes(m.desc);
int local = 0;
if ((m.access & ACC_STATIC) == 0) {
Type ctype = Type.getObjectType(owner);
current.setLocal(local++, interpreter.newValue(ctype));
}
for (int i = 0; i < args.length; ++i) {
current.setLocal(local++, interpreter.newValue(args[i]));
if (args[i].getSize() == 2) {
current.setLocal(local++, interpreter.newValue(null));
}
}
while (local < m.maxLocals) {
current.setLocal(local++, interpreter.newValue(null));
}
interpreter.init(data[0]);
merge(0, current, null);
init(owner, m);
// control flow analysis
while (top > 0) {
int insn = queue[--top];
Frame<V> f = frames[insn];
Subroutine subroutine = subroutines[insn];
queued[insn] = false;
AbstractInsnNode insnNode = null;
try {
insnNode = m.instructions.get(insn);
int insnOpcode = insnNode.getOpcode();
int insnType = insnNode.getType();
if (insnType == AbstractInsnNode.LABEL
|| insnType == AbstractInsnNode.LINE
|| insnType == AbstractInsnNode.FRAME) {
interpreter.init(data[insn]);
merge(insn + 1, f, subroutine);
newControlFlowEdge(insn, insn + 1);
} else {
// delta
interpreter.init(data[insn]);
current.init(f).execute(insnNode, interpreter);
subroutine = subroutine == null ? null : subroutine.copy();
if (insnNode instanceof JumpInsnNode) {
JumpInsnNode j = (JumpInsnNode) insnNode;
if (insnOpcode != GOTO && insnOpcode != JSR) {
merge(insn + 1, current, subroutine);
newControlFlowEdge(insn, insn + 1);
}
int jump = insns.indexOf(j.label);
if (insnOpcode == JSR) {
merge(jump, current, new Subroutine(j.label,
m.maxLocals, j));
} else {
merge(jump, current, subroutine);
}
newControlFlowEdge(insn, jump);
} else if (insnNode instanceof LookupSwitchInsnNode) {
LookupSwitchInsnNode lsi = (LookupSwitchInsnNode) insnNode;
int jump = insns.indexOf(lsi.dflt);
merge(jump, current, subroutine);
newControlFlowEdge(insn, jump);
for (int j = 0; j < lsi.labels.size(); ++j) {
LabelNode label = lsi.labels.get(j);
jump = insns.indexOf(label);
merge(jump, current, subroutine);
newControlFlowEdge(insn, jump);
}
} else if (insnNode instanceof TableSwitchInsnNode) {
TableSwitchInsnNode tsi = (TableSwitchInsnNode) insnNode;
int jump = insns.indexOf(tsi.dflt);
merge(jump, current, subroutine);
newControlFlowEdge(insn, jump);
for (int j = 0; j < tsi.labels.size(); ++j) {
LabelNode label = tsi.labels.get(j);
jump = insns.indexOf(label);
merge(jump, current, subroutine);
newControlFlowEdge(insn, jump);
}
} else if (insnOpcode == RET) {
if (subroutine == null) {
throw new AnalyzerException(insnNode,
"RET instruction outside of a sub routine");
}
for (int i = 0; i < subroutine.callers.size(); ++i) {
JumpInsnNode caller = subroutine.callers.get(i);
int call = insns.indexOf(caller);
if (frames[call] != null) {
merge(call + 1, frames[call], current,
subroutines[call], subroutine.access);
newControlFlowEdge(insn, call + 1);
}
}
} else if (insnOpcode != ATHROW && (insnOpcode < IRETURN || insnOpcode > RETURN)) {
if (subroutine != null) {
if (insnNode instanceof VarInsnNode) {
int var = ((VarInsnNode) insnNode).var;
subroutine.access[var] = true;
if (insnOpcode == LLOAD || insnOpcode == DLOAD
|| insnOpcode == LSTORE
|| insnOpcode == DSTORE) {
subroutine.access[var + 1] = true;
}
} else if (insnNode instanceof IincInsnNode) {
int var = ((IincInsnNode) insnNode).var;
subroutine.access[var] = true;
}
}
merge(insn + 1, current, subroutine);
newControlFlowEdge(insn, insn + 1);
}
}
List<TryCatchBlockNode> insnHandlers = handlers[insn];
if (insnHandlers != null) {
for (int i = 0; i < insnHandlers.size(); ++i) {
TryCatchBlockNode tcb = insnHandlers.get(i);
int jump = insns.indexOf(tcb.handler);
if (newControlFlowExceptionEdge(insn, tcb)) {
handler.init(f);
handler.clearStack();
handler.push(refV);
merge(jump, handler, subroutine);
}
}
}
} catch (AnalyzerException e) {
throw new AnalyzerException(e.node, "Error at instruction "
+ insn + ": " + e.getMessage(), e);
} catch (Exception e) {
throw new AnalyzerException(insnNode, "Error at instruction "
+ insn + ": " + e.getMessage(), e);
}
}
return frames;
}
public Frame<V>[] getFrames() {
return frames;
}
public List<TryCatchBlockNode> getHandlers(final int insn) {
return handlers[insn];
}
protected void init(String owner, MethodNode m) throws AnalyzerException {
}
protected Frame<V> newFrame(final int nLocals, final int nStack) {
return new Frame<>(nLocals, nStack);
}
protected Frame<V> newFrame(final Frame<? extends V> src) {
return new Frame<>(src);
}
protected void newControlFlowEdge(final int insn, final int successor) {
}
protected boolean newControlFlowExceptionEdge(final int insn,
final int successor) {
return true;
}
protected boolean newControlFlowExceptionEdge(final int insn,
final TryCatchBlockNode tcb) {
return newControlFlowExceptionEdge(insn, insns.indexOf(tcb.handler));
}
// -------------------------------------------------------------------------
private void merge(final int insn, final Frame<V> frame,
final Subroutine subroutine) throws AnalyzerException {
Frame<V> oldFrame = frames[insn];
Subroutine oldSubroutine = subroutines[insn];
boolean changes;
if (oldFrame == null) {
frames[insn] = newFrame(frame);
changes = true;
} else {
changes = oldFrame.merge(frame, interpreter);
}
if (oldSubroutine == null) {
if (subroutine != null) {
subroutines[insn] = subroutine.copy();
changes = true;
}
} else {
if (subroutine != null) {
changes |= oldSubroutine.merge(subroutine);
}
}
if (changes && !queued[insn]) {
queued[insn] = true;
queue[top++] = insn;
}
// delta
mergeData(insn, interpreter);
}
private void merge(final int insn, final Frame<V> beforeJSR,
final Frame<V> afterRET, final Subroutine subroutineBeforeJSR,
final boolean[] access) throws AnalyzerException {
Frame<V> oldFrame = frames[insn];
Subroutine oldSubroutine = subroutines[insn];
boolean changes;
afterRET.merge(beforeJSR, access);
if (oldFrame == null) {
frames[insn] = newFrame(afterRET);
changes = true;
} else {
changes = oldFrame.merge(afterRET, interpreter);
}
if (oldSubroutine != null && subroutineBeforeJSR != null) {
changes |= oldSubroutine.merge(subroutineBeforeJSR);
}
if (changes && !queued[insn]) {
queued[insn] = true;
queue[top++] = insn;
}
// delta
mergeData(insn, interpreter);
}
private void mergeData(int insn, MyInterpreter interpreter) {
boolean changes = false;
Data oldData = data[insn];
Data newData = interpreter.getAfterData(insn);
if (oldData == null) {
data[insn] = newData;
changes = true;
} else if (newData != null) {
Data mergedData = interpreter.merge(oldData, newData);
data[insn] = mergedData;
changes = !oldData.equals(mergedData);
}
if (changes && !queued[insn]) {
queued[insn] = true;
queue[top++] = insn;
}
}
}