1 import java.io.*;
2
3 class InstallSDE {
4 static final boolean verbose = true;
5 static final String nameSDE = "SourceDebugExtension";
6
7 byte[] orig;
8 byte[] sdeAttr;
9 byte[] gen;
10
11 int origPos = 0;
12 int genPos = 0;
13
14 int sdeIndex;
15
16 public static void main(String[] args) throws IOException {
17 if (args.length == 2) {
18 install(new File(args[0]), new File(args[1]));
19 } else if (args.length == 3) {
20 install(new File(args[0]), new File(args[1]), new File(args[2]));
21 } else {
22 abort("Usage: <command> <input class file> " +
23 "<attribute file> <output class file name>\n" +
24 "<command> <input/output class file> <attribute file>");
25 }
26 }
27
28 static void install(File inClassFile, File attrFile, File outClassFile)
29 throws IOException {
30 new InstallSDE(inClassFile, attrFile, outClassFile);
31 }
32
33 static void install(File inOutClassFile, File attrFile) throws IOException {
34 File tmpFile = new File(inOutClassFile.getPath() + "tmp");
35 new InstallSDE(inOutClassFile, attrFile, tmpFile);
36 if (!inOutClassFile.delete()) {
37 throw new IOException("inOutClassFile.delete() failed");
38 }
39 if (!tmpFile.renameTo(inOutClassFile)) {
40 throw new IOException("tmpFile.renameTo(inOutClassFile) failed");
41 }
42 }
43
44 static void abort(String msg) {
45 System.err.println(msg);
46 System.exit(1);
47 }
48
49 InstallSDE(File inClassFile, File attrFile, File outClassFile) throws IOException {
50 if (!inClassFile.exists()) {
51 abort("no such file: " + inClassFile);
52 }
53 if (!attrFile.exists()) {
54 abort("no such file: " + attrFile);
55 }
56
57 // get the bytes
58 orig = readWhole(inClassFile);
59 sdeAttr = readWhole(attrFile);
60 gen = new byte[orig.length + sdeAttr.length + 100];
61
62 // do it
63 addSDE();
64
65 // write result
66 FileOutputStream outStream = new FileOutputStream(outClassFile);
67 outStream.write(gen, 0, genPos);
68 outStream.close();
69 }
70
71 byte[] readWhole(File input) throws IOException {
72 FileInputStream inStream = new FileInputStream(input);
73 int len = (int)input.length();
74 byte[] bytes = new byte[len];
75 if (inStream.read(bytes, 0, len) != len) {
76 abort("expected size: " + len);
77 }
78 inStream.close();
79 return bytes;
80 }
81
82 void addSDE() throws UnsupportedEncodingException {
83 int i;
84 copy(4 + 2 + 2); // magic min/maj version
85 int constantPoolCountPos = genPos;
86 int constantPoolCount = readU2();
87 writeU2(constantPoolCount);
88 // copy old constant pool return index of SDE symbol, if found
89 sdeIndex = copyConstantPool(constantPoolCount);
90 if (sdeIndex < 0) {
91 // if "SourceDebugExtension" symbol not there add it
92 writeUtf8ForSDE();
93
94 // increment the countantPoolCount
95 sdeIndex = constantPoolCount;
96 ++constantPoolCount;
97 randomAccessWriteU2(constantPoolCountPos, constantPoolCount);
98
99 if (verbose) {
100 System.out.println("SourceDebugExtension not found, installed at: " +
101 sdeIndex);
102 }
103 } else {
104 if (verbose) {
105 System.out.println("SourceDebugExtension found at: " +
106 sdeIndex);
107 }
108 }
109 copy(2 + 2 + 2); // access, this, super
110 int interfaceCount = readU2();
111 writeU2(interfaceCount);
112 if (verbose) {
113 System.out.println("interfaceCount: " + interfaceCount);
114 }
115 copy(interfaceCount * 2);
116 copyMembers(); // fields
117 copyMembers(); // methods
118 int attrCountPos = genPos;
119 int attrCount = readU2();
120 writeU2(attrCount);
121 if (verbose) {
122 System.out.println("class attrCount: " + attrCount);
123 }
124 // copy the class attributes, return true if SDE attr found (not copied)
125 if (!copyAttrs(attrCount)) {
126 // we will be adding SDE and it isn't already counted
127 ++attrCount;
128 randomAccessWriteU2(attrCountPos, attrCount);
129 if (verbose) {
130 System.out.println("class attrCount incremented");
131 }
132 }
133 writeAttrForSDE(sdeIndex);
134 }
135
136 void copyMembers() {
137 int count = readU2();
138 writeU2(count);
139 if (verbose) {
140 System.out.println("members count: " + count);
141 }
142 for (int i = 0; i < count; ++i) {
143 copy(6); // access, name, descriptor
144 int attrCount = readU2();
145 writeU2(attrCount);
146 if (verbose) {
147 System.out.println("member attr count: " + attrCount);
148 }
149 copyAttrs(attrCount);
150 }
151 }
152
153 boolean copyAttrs(int attrCount) {
154 boolean sdeFound = false;
155 for (int i = 0; i < attrCount; ++i) {
156 int nameIndex = readU2();
157 // don't write old SDE
158 if (nameIndex == sdeIndex) {
159 sdeFound = true;
160 if (verbose) {
161 System.out.println("SDE attr found");
162 }
163 } else {
164 writeU2(nameIndex); // name
165 int len = readU4();
166 writeU4(len);
167 copy(len);
168 if (verbose) {
169 System.out.println("attr len: " + len);
170 }
171 }
172 }
173 return sdeFound;
174 }
175
176 void writeAttrForSDE(int index) {
177 writeU2(index);
178 writeU4(sdeAttr.length);
179 for (int i = 0; i < sdeAttr.length; ++i) {
180 writeU1(sdeAttr[i]);
181 }
182 }
183
184 void randomAccessWriteU2(int pos, int val) {
185 int savePos = genPos;
186 genPos = pos;
187 writeU2(val);
188 genPos = savePos;
189 }
190
191 int readU1() {
192 return ((int)orig[origPos++]) & 0xFF;
193 }
194
195 int readU2() {
196 int res = readU1();
197 return (res << 8) + readU1();
198 }
199
200 int readU4() {
201 int res = readU2();
202 return (res << 16) + readU2();
203 }
204
205 void writeU1(int val) {
206 gen[genPos++] = (byte)val;
207 }
208
209 void writeU2(int val) {
210 writeU1(val >> 8);
211 writeU1(val & 0xFF);
212 }
213
214 void writeU4(int val) {
215 writeU2(val >> 16);
216 writeU2(val & 0xFFFF);
217 }
218
219 void copy(int count) {
220 for (int i = 0; i < count; ++i) {
221 gen[genPos++] = orig[origPos++];
222 }
223 }
224
225 byte[] readBytes(int count) {
226 byte[] bytes = new byte[count];
227 for (int i = 0; i < count; ++i) {
228 bytes[i] = orig[origPos++];
229 }
230 return bytes;
231 }
232
233 void writeBytes(byte[] bytes) {
234 for (int i = 0; i < bytes.length; ++i) {
235 gen[genPos++] = bytes[i];
236 }
237 }
238
239 int copyConstantPool(int constantPoolCount) throws UnsupportedEncodingException {
240 int sdeIndex = -1;
241 // copy const pool index zero not in class file
242 for (int i = 1; i < constantPoolCount; ++i) {
243 int tag = readU1();
244 writeU1(tag);
245 switch (tag) {
246 case 7: // Class
247 case 8: // String
248 copy(2);
249 break;
250 case 9: // Field
251 case 10: // Method
252 case 11: // InterfaceMethod
253 case 3: // Integer
254 case 4: // Float
255 case 12: // NameAndType
256 case 18: // InvokeDynamic
257 copy(4);
258 break;
259 case 5: // Long
260 case 6: // Double
261 copy(8);
262 break;
263 case 15: // MethodHandle
264 copy(3);
265 break;
266 case 1: // Utf8
267 int len = readU2();
268 writeU2(len);
269 byte[] utf8 = readBytes(len);
270 String str = new String(utf8, "UTF-8");
271 if (verbose) {
272 System.out.println(i + " read class attr -- '" + str + "'");
273 }
274 if (str.equals(nameSDE)) {
275 sdeIndex = i;
276 }
277 writeBytes(utf8);
278 break;
279 default:
280 abort("unexpected tag: " + tag);
281 break;
282 }
283 }
284 return sdeIndex;
285 }
286
287 void writeUtf8ForSDE() {
288 int len = nameSDE.length();
289 writeU1(1); // Utf8 tag
290 writeU2(len);
291 for (int i = 0; i < len; ++i) {
292 writeU1(nameSDE.charAt(i));
293 }
294 }
295 }