BlockDumper.java revision ccf5cff3faefcf1d44d0ebc141a1f7e7dcee3c62 
1/*
2 * Copyright (C) 2007 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.android.dx.command.dump;
18
19import com.android.dx.cf.attrib.AttCode;
20import com.android.dx.cf.code.BasicBlocker;
21import com.android.dx.cf.code.ByteBlock;
22import com.android.dx.cf.code.ByteBlockList;
23import com.android.dx.cf.code.ByteCatchList;
24import com.android.dx.cf.code.BytecodeArray;
25import com.android.dx.cf.code.ConcreteMethod;
26import com.android.dx.cf.code.Ropper;
27import com.android.dx.cf.direct.CodeObserver;
28import com.android.dx.cf.direct.DirectClassFile;
29import com.android.dx.cf.direct.StdAttributeFactory;
30import com.android.dx.cf.iface.Member;
31import com.android.dx.cf.iface.Method;
32import com.android.dx.rop.code.BasicBlock;
33import com.android.dx.rop.code.BasicBlockList;
34import com.android.dx.rop.code.Insn;
35import com.android.dx.rop.code.InsnList;
36import com.android.dx.rop.code.RopMethod;
37import com.android.dx.rop.code.DexTranslationAdvice;
38import com.android.dx.rop.code.TranslationAdvice;
39import com.android.dx.rop.code.AccessFlags;
40import com.android.dx.rop.cst.CstType;
41import com.android.dx.ssa.Optimizer;
42import com.android.dx.util.ByteArray;
43import com.android.dx.util.Hex;
44import com.android.dx.util.IntList;
45
46import java.io.PrintStream;
47
48/**
49 * Utility to dump basic block info from methods in a human-friendly form.
50 */
51public class BlockDumper
52        extends BaseDumper {
53    /** whether or not to registerize (make rop blocks) */
54    private boolean rop;
55
56    /**
57     * {@code null-ok;} the class file object being constructed;
58     * becomes non-null during {@link #dump}
59     */
60    protected DirectClassFile classFile;
61
62    /** whether or not to suppress dumping */
63    protected boolean suppressDump;
64
65    /** whether this is the first method being dumped */
66    private boolean first;
67
68    /** whether or not to run the ssa optimziations */
69    private boolean optimize;
70
71    /**
72     * Dumps the given array, interpreting it as a class file and dumping
73     * methods with indications of block-level stuff.
74     *
75     * @param bytes {@code non-null;} bytes of the (alleged) class file
76     * @param out {@code non-null;} where to dump to
77     * @param filePath the file path for the class, excluding any base
78     * directory specification
79     * @param rop whether or not to registerize (make rop blocks)
80     * @param args commandline parsedArgs
81     */
82    public static void dump(byte[] bytes, PrintStream out,
83            String filePath, boolean rop, Args args) {
84        BlockDumper bd = new BlockDumper(bytes, out, filePath,
85                rop, args);
86        bd.dump();
87    }
88
89    /**
90     * Constructs an instance. This class is not publicly instantiable.
91     * Use {@link #dump}.
92     */
93    BlockDumper(byte[] bytes, PrintStream out, String filePath,
94            boolean rop, Args args) {
95        super(bytes, out, filePath, args);
96
97        this.rop = rop;
98        this.classFile = null;
99        this.suppressDump = true;
100        this.first = true;
101        this.optimize = args.optimize;
102    }
103
104    /**
105     * Does the dumping.
106     */
107    public void dump() {
108        byte[] bytes = getBytes();
109        ByteArray ba = new ByteArray(bytes);
110
111        /*
112         * First, parse the file completely, so we can safely refer to
113         * attributes, etc.
114         */
115        classFile = new DirectClassFile(ba, getFilePath(), getStrictParse());
116        classFile.setAttributeFactory(StdAttributeFactory.THE_ONE);
117        classFile.getMagic(); // Force parsing to happen.
118
119        // Next, reparse it and observe the process.
120        DirectClassFile liveCf =
121            new DirectClassFile(ba, getFilePath(), getStrictParse());
122        liveCf.setAttributeFactory(StdAttributeFactory.THE_ONE);
123        liveCf.setObserver(this);
124        liveCf.getMagic(); // Force parsing to happen.
125    }
126
127    /** {@inheritDoc} */
128    @Override
129    public void changeIndent(int indentDelta) {
130        if (!suppressDump) {
131            super.changeIndent(indentDelta);
132        }
133    }
134
135    /** {@inheritDoc} */
136    @Override
137    public void parsed(ByteArray bytes, int offset, int len, String human) {
138        if (!suppressDump) {
139            super.parsed(bytes, offset, len, human);
140        }
141    }
142
143    /**
144     * @param name method name
145     * @return true if this method should be dumped
146     */
147    protected boolean shouldDumpMethod(String name) {
148        return args.method == null || args.method.equals(name);
149    }
150
151    /** {@inheritDoc} */
152    @Override
153    public void startParsingMember(ByteArray bytes, int offset, String name,
154            String descriptor) {
155        if (descriptor.indexOf('(') < 0) {
156            // It's a field, not a method
157            return;
158        }
159
160        if (!shouldDumpMethod(name)) {
161            return;
162        }
163
164        // Reset the dump cursor to the start of the method.
165        setAt(bytes, offset);
166
167        suppressDump = false;
168
169        if (first) {
170            first = false;
171        } else {
172            parsed(bytes, offset, 0, "\n");
173        }
174
175        parsed(bytes, offset, 0, "method " + name + " " + descriptor);
176        suppressDump = true;
177    }
178
179    /** {@inheritDoc} */
180    @Override
181    public void endParsingMember(ByteArray bytes, int offset, String name,
182            String descriptor, Member member) {
183        if (!(member instanceof Method)) {
184            return;
185        }
186
187        if (!shouldDumpMethod(name)) {
188            return;
189        }
190
191        ConcreteMethod meth =
192            new ConcreteMethod((Method) member, classFile, true, true);
193
194        if (rop) {
195            ropDump(meth);
196        } else {
197            regularDump(meth);
198        }
199    }
200
201    /**
202     * Does a regular basic block dump.
203     *
204     * @param meth {@code non-null;} method data to dump
205     */
206    private void regularDump(ConcreteMethod meth) {
207        BytecodeArray code = meth.getCode();
208        ByteArray bytes = code.getBytes();
209        ByteBlockList list = BasicBlocker.identifyBlocks(meth);
210        int sz = list.size();
211        CodeObserver codeObserver = new CodeObserver(bytes, BlockDumper.this);
212
213        // Reset the dump cursor to the start of the bytecode.
214        setAt(bytes, 0);
215
216        suppressDump = false;
217
218        int byteAt = 0;
219        for (int i = 0; i < sz; i++) {
220            ByteBlock bb = list.get(i);
221            int start = bb.getStart();
222            int end = bb.getEnd();
223
224            if (byteAt < start) {
225                parsed(bytes, byteAt, start - byteAt,
226                       "dead code " + Hex.u2(byteAt) + ".." + Hex.u2(start));
227            }
228
229            parsed(bytes, start, 0,
230                    "block " + Hex.u2(bb.getLabel()) + ": " +
231                    Hex.u2(start) + ".." + Hex.u2(end));
232            changeIndent(1);
233
234            int len;
235            for (int j = start; j < end; j += len) {
236                len = code.parseInstruction(j, codeObserver);
237                codeObserver.setPreviousOffset(j);
238            }
239
240            IntList successors = bb.getSuccessors();
241            int ssz = successors.size();
242            if (ssz == 0) {
243                parsed(bytes, end, 0, "returns");
244            } else {
245                for (int j = 0; j < ssz; j++) {
246                    int succ = successors.get(j);
247                    parsed(bytes, end, 0, "next " + Hex.u2(succ));
248                }
249            }
250
251            ByteCatchList catches = bb.getCatches();
252            int csz = catches.size();
253            for (int j = 0; j < csz; j++) {
254                ByteCatchList.Item one = catches.get(j);
255                CstType exceptionClass = one.getExceptionClass();
256                parsed(bytes, end, 0,
257                       "catch " +
258                       ((exceptionClass == CstType.OBJECT) ? "<any>" :
259                        exceptionClass.toHuman()) + " -> " +
260                       Hex.u2(one.getHandlerPc()));
261            }
262
263            changeIndent(-1);
264            byteAt = end;
265        }
266
267        int end = bytes.size();
268        if (byteAt < end) {
269            parsed(bytes, byteAt, end - byteAt,
270                    "dead code " + Hex.u2(byteAt) + ".." + Hex.u2(end));
271        }
272
273        suppressDump = true;
274    }
275
276    /**
277     * Does a registerizing dump.
278     *
279     * @param meth {@code non-null;} method data to dump
280     */
281    private void ropDump(ConcreteMethod meth) {
282        TranslationAdvice advice = DexTranslationAdvice.THE_ONE;
283        BytecodeArray code = meth.getCode();
284        ByteArray bytes = code.getBytes();
285        RopMethod rmeth = Ropper.convert(meth, advice);
286        StringBuffer sb = new StringBuffer(2000);
287
288        if (optimize) {
289            boolean isStatic = AccessFlags.isStatic(meth.getAccessFlags());
290            int paramWidth = computeParamWidth(meth, isStatic);
291            rmeth =
292                Optimizer.optimize(rmeth, paramWidth, isStatic, true, advice);
293        }
294
295        BasicBlockList blocks = rmeth.getBlocks();
296        int[] order = blocks.getLabelsInOrder();
297
298        sb.append("first " + Hex.u2(rmeth.getFirstLabel()) + "\n");
299
300        for (int label : order) {
301            BasicBlock bb = blocks.get(blocks.indexOfLabel(label));
302            sb.append("block ");
303            sb.append(Hex.u2(label));
304            sb.append("\n");
305
306            IntList preds = rmeth.labelToPredecessors(label);
307            int psz = preds.size();
308            for (int i = 0; i < psz; i++) {
309                sb.append("  pred ");
310                sb.append(Hex.u2(preds.get(i)));
311                sb.append("\n");
312            }
313
314            InsnList il = bb.getInsns();
315            int ilsz = il.size();
316            for (int i = 0; i < ilsz; i++) {
317                Insn one = il.get(i);
318                sb.append("  ");
319                sb.append(il.get(i).toHuman());
320                sb.append("\n");
321            }
322
323            IntList successors = bb.getSuccessors();
324            int ssz = successors.size();
325            if (ssz == 0) {
326                sb.append("  returns\n");
327            } else {
328                int primary = bb.getPrimarySuccessor();
329                for (int i = 0; i < ssz; i++) {
330                    int succ = successors.get(i);
331                    sb.append("  next ");
332                    sb.append(Hex.u2(succ));
333
334                    if ((ssz != 1) && (succ == primary)) {
335                        sb.append(" *");
336                    }
337
338                    sb.append("\n");
339                }
340            }
341        }
342
343        suppressDump = false;
344        setAt(bytes, 0);
345        parsed(bytes, 0, bytes.size(), sb.toString());
346        suppressDump = true;
347    }
348}
349