Fri, 24 Apr 2020 03:58:51 +0100
Merge
1 /*
2 * Copyright (c) 2013, 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.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
24 import java.io.*;
25 import com.sun.tools.classfile.*;
27 /**
28 * The {@code ClassFileVisitor} reads a class file using the
29 * {@code com.sun.tools.classfile} library. It iterates over the methods
30 * in a class, and checks MethodParameters attributes against JLS
31 * requirements, as well as assumptions about the javac implementations.
32 * <p>
33 * It enforces the following rules:
34 * <ul>
35 * <li>All non-synthetic methods with arguments must have the
36 * MethodParameters attribute. </li>
37 * <li>At most one MethodParameters attribute per method.</li>
38 * <li>An empty MethodParameters attribute is not allowed (i.e. no
39 * attribute for methods taking no parameters).</li>
40 * <li>The number of recorded parameter names much equal the number
41 * of parameters, including any implicit or synthetic parameters generated
42 * by the compiler.</li>
43 * <li>Although the spec allow recording parameters with no name, the javac
44 * implementation is assumed to record a name for all parameters. That is,
45 * the Methodparameters attribute must record a non-zero, valid constant
46 * pool index for each parameter.</li>
47 * <li>Check presence, expected names (e.g. this$N, $enum$name, ...) and flags
48 * (e.g. ACC_SYNTHETIC, ACC_MANDATED) for compiler generated parameters.</li>
49 * <li>Names of explicit parameters must reflect the names in the Java source.
50 * This is checked by assuming a design pattern where any name is permitted
51 * for the first explicit parameter. For subsequent parameters the following
52 * rule is checked: <i>param[n] == ++param[n-1].charAt(0) + param[n-1]</i>
53 * </ul>
54 */
55 class ClassFileVisitor extends Tester.Visitor {
57 Tester tester;
59 public String cname;
60 public boolean isEnum;
61 public boolean isInterface;
62 public boolean isInner;
63 public boolean isPublic;
64 public boolean isStatic;
65 public boolean isAnon;
66 public ClassFile classFile;
69 public ClassFileVisitor(Tester tester) {
70 super(tester);
71 }
73 public void error(String msg) {
74 super.error("classfile: " + msg);
75 }
77 public void warn(String msg) {
78 super.warn("classfile: " + msg);
79 }
81 /**
82 * Read the class and determine some key characteristics, like if it's
83 * an enum, or inner class, etc.
84 */
85 void visitClass(final String cname, final File cfile, final StringBuilder sb) throws Exception {
86 this.cname = cname;
87 classFile = ClassFile.read(cfile);
88 isEnum = classFile.access_flags.is(AccessFlags.ACC_ENUM);
89 isInterface = classFile.access_flags.is(AccessFlags.ACC_INTERFACE);
90 isPublic = classFile.access_flags.is(AccessFlags.ACC_PUBLIC);
91 isInner = false;
92 isStatic = false;
93 isAnon = false;
95 Attribute attr = classFile.getAttribute("InnerClasses");
96 if (attr != null) attr.accept(new InnerClassVisitor(), null);
97 isAnon = isInner & isAnon;
99 sb.append(isStatic ? "static " : "")
100 .append(isPublic ? "public " : "")
101 .append(isEnum ? "enum " : isInterface ? "interface " : "class ")
102 .append(cname).append(" -- ");
103 if (isInner) {
104 sb.append(isAnon ? "anon" : "inner");
105 }
106 sb.append("\n");
108 for (Method method : classFile.methods) {
109 new MethodVisitor().visitMethod(method, sb);
110 }
111 }
113 /**
114 * Used to visit InnerClasses_attribute of a class,
115 * to determne if this class is an local class, and anonymous
116 * inner class or a none-static member class. These types of
117 * classes all have an containing class instances field that
118 * requires an implicit or synthetic constructor argument.
119 */
120 class InnerClassVisitor extends AttributeVisitor<Void, Void> {
121 public Void visitInnerClasses(InnerClasses_attribute iattr, Void v) {
122 try{
123 for (InnerClasses_attribute.Info info : iattr.classes) {
124 if (info.getInnerClassInfo(classFile.constant_pool) == null) continue;
125 String in = info.getInnerClassInfo(classFile.constant_pool).getName();
126 if (in == null || !cname.equals(in)) continue;
127 isInner = true;
128 isAnon = null == info.getInnerName(classFile.constant_pool);
129 isStatic = info.inner_class_access_flags.is(AccessFlags.ACC_STATIC);
130 break;
131 }
132 } catch(Exception e) {
133 throw new IllegalStateException(e);
134 }
135 return null;
136 }
137 }
139 /**
140 * Check the MethodParameters attribute of a method.
141 */
142 class MethodVisitor extends AttributeVisitor<Void, StringBuilder> {
144 public String mName;
145 public Descriptor mDesc;
146 public int mParams;
147 public int mAttrs;
148 public int mNumParams;
149 public boolean mSynthetic;
150 public boolean mIsLambda;
151 public boolean mIsConstructor;
152 public boolean mIsClinit;
153 public boolean mIsBridge;
154 public boolean isFinal;
155 public String prefix;
157 void visitMethod(Method method, StringBuilder sb) throws Exception {
159 mName = method.getName(classFile.constant_pool);
160 mDesc = method.descriptor;
161 mParams = mDesc.getParameterCount(classFile.constant_pool);
162 mAttrs = method.attributes.attrs.length;
163 mNumParams = -1; // no MethodParameters attribute found
164 mSynthetic = method.access_flags.is(AccessFlags.ACC_SYNTHETIC);
165 mIsConstructor = mName.equals("<init>");
166 mIsClinit = mName.equals("<clinit>");
167 prefix = cname + "." + mName + "() - ";
168 mIsBridge = method.access_flags.is(AccessFlags.ACC_BRIDGE);
169 mIsLambda = mSynthetic && mName.startsWith("lambda$");
171 if (mIsClinit) {
172 sb = new StringBuilder(); // Discard output
173 }
174 sb.append(cname).append(".").append(mName).append("(");
176 for (Attribute a : method.attributes) {
177 a.accept(this, sb);
178 }
179 if (mNumParams == -1) {
180 if (mSynthetic) {
181 // We don't generate MethodParameters attribute for synthetic
182 // methods, so we are creating a parameter pattern to match
183 // ReflectionVisitor API output.
184 for (int i = 0; i < mParams; i++) {
185 if (i == 0)
186 sb.append("arg").append(i);
187 else
188 sb.append(", arg").append(i);
189 }
190 sb.append(")/*synthetic*/");
191 } else {
192 sb.append(")");
193 }
194 }
195 sb.append("\n");
197 // IMPL: methods with arguments must have a MethodParameters
198 // attribute, except possibly some synthetic methods.
199 if (mNumParams == -1 && mParams > 0 && ! mSynthetic) {
200 error(prefix + "missing MethodParameters attribute");
201 }
202 }
204 public Void visitMethodParameters(MethodParameters_attribute mp,
205 StringBuilder sb) {
207 // SPEC: At most one MethodParameters attribute allowed
208 if (mNumParams != -1) {
209 error(prefix + "Multiple MethodParameters attributes");
210 return null;
211 }
213 mNumParams = mp.method_parameter_table_length;
215 // SPEC: An empty attribute is not allowed!
216 if (mNumParams == 0) {
217 error(prefix + "0 length MethodParameters attribute");
218 return null;
219 }
221 // SPEC: one name per parameter.
222 if (mNumParams != mParams) {
223 error(prefix + "found " + mNumParams +
224 " parameters, expected " + mParams);
225 return null;
226 }
228 // IMPL: Whether MethodParameters attributes will be generated
229 // for some synthetics is unresolved. For now, assume no.
230 if (mSynthetic && !mIsLambda) {
231 warn(prefix + "synthetic has MethodParameter attribute");
232 }
234 String sep = "";
235 String userParam = null;
236 for (int x = 0; x < mNumParams; x++) {
237 isFinal = (mp.method_parameter_table[x].flags & AccessFlags.ACC_FINAL) != 0;
238 // IMPL: Assume all parameters are named, something.
239 int cpi = mp.method_parameter_table[x].name_index;
240 if (cpi == 0) {
241 error(prefix + "name expected, param[" + x + "]");
242 return null;
243 }
245 // SPEC: a non 0 index, must be valid!
246 String param = null;
247 try {
248 param = classFile.constant_pool.getUTF8Value(cpi);
249 if (isFinal)
250 param = "final " + param;
251 sb.append(sep).append(param);
252 sep = ", ";
253 } catch(ConstantPoolException e) {
254 error(prefix + "invalid index " + cpi + " for param["
255 + x + "]");
256 return null;
257 }
260 // Check availability, flags and special names
261 int check = checkParam(mp, param, x, sb, isFinal);
262 if (check < 0) {
263 return null;
264 }
266 // TEST: check test assumptions about parameter name.
267 // Expected names are calculated starting with the
268 // 2nd explicit (user given) parameter.
269 // param[n] == ++param[n-1].charAt(0) + param[n-1]
270 String expect = null;
271 if (userParam != null) {
272 char c = userParam.charAt(0);
273 expect = (++c) + userParam;
274 }
275 if(isFinal && expect != null)
276 expect = "final " + expect;
277 if (check > 0) {
278 if(isFinal) {
279 userParam = param.substring(6);
280 } else {
281 userParam = param;
282 }
283 }
284 if (expect != null && !param.equals(expect)) {
285 error(prefix + "param[" + x + "]='"
286 + param + "' expected '" + expect + "'");
287 return null;
288 }
289 }
290 if (mSynthetic) {
291 sb.append(")/*synthetic*/");
292 } else {
293 sb.append(")");
294 }
295 return null;
296 }
298 /*
299 * Check a parameter for conformity to JLS and javac specific
300 * assumptions.
301 * Return -1, if an error is detected. Otherwise, return 0, if
302 * the parameter is compiler generated, or 1 for an (presumably)
303 * explicitly declared parameter.
304 */
305 int checkParam(MethodParameters_attribute mp, String param, int index,
306 StringBuilder sb, boolean isFinal) {
308 boolean synthetic = (mp.method_parameter_table[index].flags
309 & AccessFlags.ACC_SYNTHETIC) != 0;
310 boolean mandated = (mp.method_parameter_table[index].flags
311 & AccessFlags.ACC_MANDATED) != 0;
313 // Setup expectations for flags and special names
314 String expect = null;
315 boolean allowMandated = false;
316 boolean allowSynthetic = false;
317 if (mSynthetic || synthetic) {
318 // not an implementation gurantee, but okay for now
319 expect = "arg" + index; // default
320 }
321 if (mIsConstructor) {
322 if (isEnum) {
323 if (index == 0) {
324 expect = "\\$enum\\$name";
325 allowSynthetic = true;
326 } else if(index == 1) {
327 expect = "\\$enum\\$ordinal";
328 allowSynthetic = true;
329 }
330 } else if (index == 0) {
331 if (isAnon) {
332 expect = "this\\$[0-9]+";
333 allowMandated = true;
334 if (isFinal) {
335 expect = "final this\\$[0-9]+";
336 }
337 } else if (isInner && !isStatic) {
338 expect = "this\\$[0-9]+";
339 allowMandated = true;
340 if (!isPublic) {
341 // some but not all non-public inner classes
342 // have synthetic argument. For now we give
343 // the test a bit of slack and allow either.
344 allowSynthetic = true;
345 }
346 if (isFinal) {
347 expect = "final this\\$[0-9]+";
348 }
349 }
350 }
351 } else if (isEnum && mNumParams == 1 && index == 0 && mName.equals("valueOf")) {
352 expect = "name";
353 allowMandated = true;
354 } else if (mIsBridge || mIsLambda) {
355 allowSynthetic = true;
356 /* you can't expect an special name for bridges' parameters.
357 * The name of the original parameters are now copied. Likewise
358 * for a method encoding the lambda expression, names are derived
359 * from source lambda's parameters and captured enclosing locals.
360 */
361 expect = null;
362 }
363 if (mandated) sb.append("/*implicit*/");
364 if (synthetic) sb.append("/*synthetic*/");
366 // IMPL: our rules a somewhat fuzzy, sometimes allowing both mandated
367 // and synthetic. However, a parameters cannot be both.
368 if (mandated && synthetic) {
369 error(prefix + "param[" + index + "] == \"" + param
370 + "\" ACC_SYNTHETIC and ACC_MANDATED");
371 return -1;
372 }
373 // ... but must be either, if both "allowed".
374 if (!(mandated || synthetic) && allowMandated && allowSynthetic) {
375 error(prefix + "param[" + index + "] == \"" + param
376 + "\" expected ACC_MANDATED or ACC_SYNTHETIC");
377 return -1;
378 }
380 // ... if only one is "allowed", we meant "required".
381 if (!mandated && allowMandated && !allowSynthetic) {
382 error(prefix + "param[" + index + "] == \"" + param
383 + "\" expected ACC_MANDATED");
384 return -1;
385 }
386 if (!synthetic && !allowMandated && allowSynthetic) {
387 error(prefix + "param[" + index + "] == \"" + param
388 + "\" expected ACC_SYNTHETIC");
389 return -1;
390 }
392 // ... and not "allowed", means prohibited.
393 if (mandated && !allowMandated) {
394 error(prefix + "param[" + index + "] == \"" + param
395 + "\" unexpected, is ACC_MANDATED");
396 return -1;
397 }
398 if (synthetic && !allowSynthetic) {
399 error(prefix + "param[" + index + "] == \"" + param
400 + "\" unexpected, is ACC_SYNTHETIC");
401 return -1;
402 }
404 // Test special name expectations
405 if (expect != null) {
406 if (param.matches(expect)) {
407 return 0;
408 }
409 error(prefix + "param[" + index + "]='" + param +
410 "' expected '" + expect + "'");
411 return -1;
412 }
414 // No further checking for synthetic methods.
415 if (mSynthetic) {
416 return 0;
417 }
419 // Otherwise, do check test parameter naming convention.
420 return 1;
421 }
422 }
423 }