ConstantWriter.java revision 2942:08092deced3f 
1/*
2 * Copyright (c) 2007, 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.  Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26package com.sun.tools.javap;
27
28import com.sun.tools.classfile.ClassFile;
29import com.sun.tools.classfile.ConstantPool;
30import com.sun.tools.classfile.ConstantPoolException;
31
32import static com.sun.tools.classfile.ConstantPool.*;
33
34/*
35 *  Write a constant pool entry.
36 *
37 *  <p><b>This is NOT part of any supported API.
38 *  If you write code that depends on this, you do so at your own risk.
39 *  This code and its internal interfaces are subject to change or
40 *  deletion without notice.</b>
41 */
42public class ConstantWriter extends BasicWriter {
43    public static ConstantWriter instance(Context context) {
44        ConstantWriter instance = context.get(ConstantWriter.class);
45        if (instance == null)
46            instance = new ConstantWriter(context);
47        return instance;
48    }
49
50    protected ConstantWriter(Context context) {
51        super(context);
52        context.put(ConstantWriter.class, this);
53        classWriter = ClassWriter.instance(context);
54        options = Options.instance(context);
55    }
56
57    protected void writeConstantPool() {
58        ConstantPool constant_pool = classWriter.getClassFile().constant_pool;
59        writeConstantPool(constant_pool);
60    }
61
62    protected void writeConstantPool(ConstantPool constant_pool) {
63        ConstantPool.Visitor<Integer, Void> v = new ConstantPool.Visitor<Integer,Void>() {
64            public Integer visitClass(CONSTANT_Class_info info, Void p) {
65                print("#" + info.name_index);
66                tab();
67                println("// " + stringValue(info));
68                return 1;
69            }
70
71            public Integer visitDouble(CONSTANT_Double_info info, Void p) {
72                println(stringValue(info));
73                return 2;
74            }
75
76            public Integer visitFieldref(CONSTANT_Fieldref_info info, Void p) {
77                print("#" + info.class_index + ".#" + info.name_and_type_index);
78                tab();
79                println("// " + stringValue(info));
80                return 1;
81            }
82
83            public Integer visitFloat(CONSTANT_Float_info info, Void p) {
84                println(stringValue(info));
85                return 1;
86            }
87
88            public Integer visitInteger(CONSTANT_Integer_info info, Void p) {
89                println(stringValue(info));
90                return 1;
91            }
92
93            public Integer visitInterfaceMethodref(CONSTANT_InterfaceMethodref_info info, Void p) {
94                print("#" + info.class_index + ".#" + info.name_and_type_index);
95                tab();
96                println("// " + stringValue(info));
97                return 1;
98            }
99
100            public Integer visitInvokeDynamic(CONSTANT_InvokeDynamic_info info, Void p) {
101                print("#" + info.bootstrap_method_attr_index + ":#" + info.name_and_type_index);
102                tab();
103                println("// " + stringValue(info));
104                return 1;
105            }
106
107            public Integer visitLong(CONSTANT_Long_info info, Void p) {
108                println(stringValue(info));
109                return 2;
110            }
111
112            public Integer visitNameAndType(CONSTANT_NameAndType_info info, Void p) {
113                print("#" + info.name_index + ":#" + info.type_index);
114                tab();
115                println("// " + stringValue(info));
116                return 1;
117            }
118
119            public Integer visitMethodref(CONSTANT_Methodref_info info, Void p) {
120                print("#" + info.class_index + ".#" + info.name_and_type_index);
121                tab();
122                println("// " + stringValue(info));
123                return 1;
124            }
125
126            public Integer visitMethodHandle(CONSTANT_MethodHandle_info info, Void p) {
127                print("#" + info.reference_kind.tag + ":#" + info.reference_index);
128                tab();
129                println("// " + stringValue(info));
130                return 1;
131            }
132
133            public Integer visitMethodType(CONSTANT_MethodType_info info, Void p) {
134                print("#" + info.descriptor_index);
135                tab();
136                println("//  " + stringValue(info));
137                return 1;
138            }
139
140            public Integer visitString(CONSTANT_String_info info, Void p) {
141                print("#" + info.string_index);
142                tab();
143                println("// " + stringValue(info));
144                return 1;
145            }
146
147            public Integer visitUtf8(CONSTANT_Utf8_info info, Void p) {
148                println(stringValue(info));
149                return 1;
150            }
151
152        };
153        println("Constant pool:");
154        indent(+1);
155        int width = String.valueOf(constant_pool.size()).length() + 1;
156        int cpx = 1;
157        while (cpx < constant_pool.size()) {
158            print(String.format("%" + width + "s", ("#" + cpx)));
159            try {
160                CPInfo cpInfo = constant_pool.get(cpx);
161                print(String.format(" = %-18s ", cpTagName(cpInfo)));
162                cpx += cpInfo.accept(v, null);
163            } catch (ConstantPool.InvalidIndex ex) {
164                // should not happen
165            }
166        }
167        indent(-1);
168    }
169
170    protected void write(int cpx) {
171        ClassFile classFile = classWriter.getClassFile();
172        if (cpx == 0) {
173            print("#0");
174            return;
175        }
176
177        CPInfo cpInfo;
178        try {
179            cpInfo = classFile.constant_pool.get(cpx);
180        } catch (ConstantPoolException e) {
181            print("#" + cpx);
182            return;
183        }
184
185        int tag = cpInfo.getTag();
186        switch (tag) {
187            case CONSTANT_Methodref:
188            case CONSTANT_InterfaceMethodref:
189            case CONSTANT_Fieldref:
190                // simplify references within this class
191                CPRefInfo ref = (CPRefInfo) cpInfo;
192                try {
193                    if (ref.class_index == classFile.this_class)
194                         cpInfo = classFile.constant_pool.get(ref.name_and_type_index);
195                } catch (ConstantPool.InvalidIndex e) {
196                    // ignore, for now
197                }
198        }
199        print(tagName(tag) + " " + stringValue(cpInfo));
200    }
201
202    String cpTagName(CPInfo cpInfo) {
203        String n = cpInfo.getClass().getSimpleName();
204        return n.replace("CONSTANT_", "").replace("_info", "");
205    }
206
207    String tagName(int tag) {
208        switch (tag) {
209            case CONSTANT_Utf8:
210                return "Utf8";
211            case CONSTANT_Integer:
212                return "int";
213            case CONSTANT_Float:
214                return "float";
215            case CONSTANT_Long:
216                return "long";
217            case CONSTANT_Double:
218                return "double";
219            case CONSTANT_Class:
220                return "class";
221            case CONSTANT_String:
222                return "String";
223            case CONSTANT_Fieldref:
224                return "Field";
225            case CONSTANT_MethodHandle:
226                return "MethodHandle";
227            case CONSTANT_MethodType:
228                return "MethodType";
229            case CONSTANT_Methodref:
230                return "Method";
231            case CONSTANT_InterfaceMethodref:
232                return "InterfaceMethod";
233            case CONSTANT_InvokeDynamic:
234                return "InvokeDynamic";
235            case CONSTANT_NameAndType:
236                return "NameAndType";
237            default:
238                return "(unknown tag " + tag + ")";
239        }
240    }
241
242    String stringValue(int constant_pool_index) {
243        ClassFile classFile = classWriter.getClassFile();
244        try {
245            return stringValue(classFile.constant_pool.get(constant_pool_index));
246        } catch (ConstantPool.InvalidIndex e) {
247            return report(e);
248        }
249    }
250
251    String stringValue(CPInfo cpInfo) {
252        return stringValueVisitor.visit(cpInfo);
253    }
254
255    StringValueVisitor stringValueVisitor = new StringValueVisitor();
256
257    private class StringValueVisitor implements ConstantPool.Visitor<String, Void> {
258        public String visit(CPInfo info) {
259            return info.accept(this, null);
260        }
261
262        public String visitClass(CONSTANT_Class_info info, Void p) {
263            return getCheckedName(info);
264        }
265
266        String getCheckedName(CONSTANT_Class_info info) {
267            try {
268                return checkName(info.getName());
269            } catch (ConstantPoolException e) {
270                return report(e);
271            }
272        }
273
274        public String visitDouble(CONSTANT_Double_info info, Void p) {
275            return info.value + "d";
276        }
277
278        public String visitFieldref(CONSTANT_Fieldref_info info, Void p) {
279            return visitRef(info, p);
280        }
281
282        public String visitFloat(CONSTANT_Float_info info, Void p) {
283            return info.value + "f";
284        }
285
286        public String visitInteger(CONSTANT_Integer_info info, Void p) {
287            return String.valueOf(info.value);
288        }
289
290        public String visitInterfaceMethodref(CONSTANT_InterfaceMethodref_info info, Void p) {
291            return visitRef(info, p);
292        }
293
294        public String visitInvokeDynamic(CONSTANT_InvokeDynamic_info info, Void p) {
295            try {
296                String callee = stringValue(info.getNameAndTypeInfo());
297                return "#" + info.bootstrap_method_attr_index + ":" + callee;
298            } catch (ConstantPoolException e) {
299                return report(e);
300            }
301        }
302
303        public String visitLong(CONSTANT_Long_info info, Void p) {
304            return info.value + "l";
305        }
306
307        public String visitNameAndType(CONSTANT_NameAndType_info info, Void p) {
308            return getCheckedName(info) + ":" + getType(info);
309        }
310
311        String getCheckedName(CONSTANT_NameAndType_info info) {
312            try {
313                return checkName(info.getName());
314            } catch (ConstantPoolException e) {
315                return report(e);
316            }
317        }
318
319        String getType(CONSTANT_NameAndType_info info) {
320            try {
321                return info.getType();
322            } catch (ConstantPoolException e) {
323                return report(e);
324            }
325        }
326
327        public String visitMethodHandle(CONSTANT_MethodHandle_info info, Void p) {
328            try {
329                return info.reference_kind.name + " " + stringValue(info.getCPRefInfo());
330            } catch (ConstantPoolException e) {
331                return report(e);
332            }
333        }
334
335        public String visitMethodType(CONSTANT_MethodType_info info, Void p) {
336            try {
337                return info.getType();
338            } catch (ConstantPoolException e) {
339                return report(e);
340            }
341        }
342
343        public String visitMethodref(CONSTANT_Methodref_info info, Void p) {
344            return visitRef(info, p);
345        }
346
347        public String visitString(CONSTANT_String_info info, Void p) {
348            try {
349                ClassFile classFile = classWriter.getClassFile();
350                int string_index = info.string_index;
351                return stringValue(classFile.constant_pool.getUTF8Info(string_index));
352            } catch (ConstantPoolException e) {
353                return report(e);
354            }
355        }
356
357        public String visitUtf8(CONSTANT_Utf8_info info, Void p) {
358            String s = info.value;
359            StringBuilder sb = new StringBuilder();
360            for (int i = 0; i < s.length(); i++) {
361                char c = s.charAt(i);
362                switch (c) {
363                    case '\t':
364                        sb.append('\\').append('t');
365                        break;
366                    case '\n':
367                        sb.append('\\').append('n');
368                        break;
369                    case '\r':
370                        sb.append('\\').append('r');
371                        break;
372                    case '\b':
373                        sb.append('\\').append('b');
374                        break;
375                    case '\f':
376                        sb.append('\\').append('f');
377                        break;
378                    case '\"':
379                        sb.append('\\').append('\"');
380                        break;
381                    case '\'':
382                        sb.append('\\').append('\'');
383                        break;
384                    case '\\':
385                        sb.append('\\').append('\\');
386                        break;
387                    default:
388                        sb.append(c);
389                }
390            }
391            return sb.toString();
392        }
393
394        String visitRef(CPRefInfo info, Void p) {
395            String cn = getCheckedClassName(info);
396            String nat;
397            try {
398                nat = stringValue(info.getNameAndTypeInfo());
399            } catch (ConstantPoolException e) {
400                nat = report(e);
401            }
402            return cn + "." + nat;
403        }
404
405        String getCheckedClassName(CPRefInfo info) {
406            try {
407                return checkName(info.getClassName());
408            } catch (ConstantPoolException e) {
409                return report(e);
410            }
411        }
412    }
413
414    /* If name is a valid binary name, return it; otherwise quote it. */
415    private static String checkName(String name) {
416        if (name == null)
417            return "null";
418
419        int len = name.length();
420        if (len == 0)
421            return "\"\"";
422
423        int cc = '/';
424        int cp;
425        for (int k = 0; k < len; k += Character.charCount(cp)) {
426            cp = name.codePointAt(k);
427            if ((cc == '/' && !Character.isJavaIdentifierStart(cp))
428                    || (cp != '/' && !Character.isJavaIdentifierPart(cp))) {
429                return "\"" + addEscapes(name) + "\"";
430            }
431            cc = cp;
432        }
433
434        return name;
435    }
436
437    /* If name requires escapes, put them in, so it can be a string body. */
438    private static String addEscapes(String name) {
439        String esc = "\\\"\n\t";
440        String rep = "\\\"nt";
441        StringBuilder buf = null;
442        int nextk = 0;
443        int len = name.length();
444        for (int k = 0; k < len; k++) {
445            char cp = name.charAt(k);
446            int n = esc.indexOf(cp);
447            if (n >= 0) {
448                if (buf == null)
449                    buf = new StringBuilder(len * 2);
450                if (nextk < k)
451                    buf.append(name, nextk, k);
452                buf.append('\\');
453                buf.append(rep.charAt(n));
454                nextk = k+1;
455            }
456        }
457        if (buf == null)
458            return name;
459        if (nextk < len)
460            buf.append(name, nextk, len);
461        return buf.toString();
462    }
463
464    private ClassWriter classWriter;
465    private Options options;
466}
467