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src/jdk.compiler/share/classes/com/sun/tools/javac/jvm/PoolWriter.java

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 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 
 26 package com.sun.tools.javac.jvm;
 27 
 28 import com.sun.tools.javac.code.Kinds.Kind;
 29 import com.sun.tools.javac.code.Symbol;
 30 import com.sun.tools.javac.code.Symbol.ClassSymbol;
 31 import com.sun.tools.javac.code.Symbol.DynamicMethodSymbol;
 32 import com.sun.tools.javac.code.Symbol.MethodHandleSymbol;
 33 import com.sun.tools.javac.code.Symbol.ModuleSymbol;
 34 import com.sun.tools.javac.code.Symbol.PackageSymbol;
 35 import com.sun.tools.javac.code.Type;

 36 import com.sun.tools.javac.code.Types;
 37 import com.sun.tools.javac.jvm.ClassWriter.PoolOverflow;
 38 import com.sun.tools.javac.jvm.ClassWriter.StringOverflow;
 39 import com.sun.tools.javac.jvm.PoolConstant.LoadableConstant;
 40 import com.sun.tools.javac.jvm.PoolConstant.LoadableConstant.BasicConstant;
 41 import com.sun.tools.javac.jvm.PoolConstant.Dynamic;
 42 import com.sun.tools.javac.jvm.PoolConstant.Dynamic.BsmKey;
 43 import com.sun.tools.javac.jvm.PoolConstant.NameAndType;
 44 import com.sun.tools.javac.util.ByteBuffer;
 45 import com.sun.tools.javac.util.List;
 46 import com.sun.tools.javac.util.Name;
 47 import com.sun.tools.javac.util.Names;
 48 
 49 import java.io.IOException;
 50 import java.io.OutputStream;
 51 import java.util.ArrayDeque;
 52 import java.util.HashMap;

 53 import java.util.LinkedHashMap;
 54 import java.util.LinkedHashSet;
 55 import java.util.Map;

 56 
 57 import static com.sun.tools.javac.code.Kinds.Kind.TYP;
 58 import static com.sun.tools.javac.code.TypeTag.ARRAY;
 59 import static com.sun.tools.javac.code.TypeTag.CLASS;
 60 import static com.sun.tools.javac.jvm.ClassFile.CONSTANT_Class;
 61 import static com.sun.tools.javac.jvm.ClassFile.CONSTANT_MethodType;
 62 import static com.sun.tools.javac.jvm.ClassFile.externalize;
 63 
 64 /**
 65  * Pool interface towards {@code ClassWriter}. Exposes methods to encode and write javac entities
 66  * into the constant pool.
 67  *
 68  *  <p><b>This is NOT part of any supported API.
 69  *  If you write code that depends on this, you do so at your own risk.
 70  *  This code and its internal interfaces are subject to change or
 71  *  deletion without notice.</b>
 72  */
 73 public class PoolWriter {
 74 
 75     /** Max number of constant pool entries. */
 76     public static final int MAX_ENTRIES = 0xFFFF;
 77 
 78     /** Max number of char in a string constant. */
 79     public static final int MAX_STRING_LENGTH = 0xFFFF;
 80 
 81     private static final int POOL_BUF_SIZE = 0x7fff;
 82 
 83     private final Types types;
 84 
 85     private final Names names;
 86 
 87     /** Pool helper **/
 88     final WriteablePoolHelper pool;
 89 
 90     /** Sole signature generator */
 91     final SharedSignatureGenerator signatureGen;
 92 
 93     /** The inner classes to be written, as an ordered set (enclosing first). */
 94     LinkedHashSet<ClassSymbol> innerClasses = new LinkedHashSet<>();
 95 


 96     /** The list of entries in the BootstrapMethods attribute. */
 97     Map<BsmKey, Integer> bootstrapMethods = new LinkedHashMap<>();
 98 
 99     public PoolWriter(Types types, Names names) {
100         this.types = types;
101         this.names = names;
102         this.signatureGen = new SharedSignatureGenerator(types);
103         this.pool = new WriteablePoolHelper();
104     }
105 
106     /**
107      * Puts a class symbol into the pool and return its index.
108      */
109     int putClass(ClassSymbol csym) {
110         return putClass(csym.type);
111     }
112 
113     /**
114      * Puts a type into the pool and return its index. The type could be either a class, a type variable
115      * or an array type.
116      */
117     int putClass(Type t) {






118         return pool.writeIfNeeded(types.erasure(t));
119     }
120 








121     /**
122      * Puts a member reference into the constant pool. Valid members are either field or method symbols.
123      */
124     int putMember(Symbol s) {
125         return pool.writeIfNeeded(s);
126     }
127 
128     /**
129      * Puts a dynamic reference into the constant pool and return its index.
130      */
131     int putDynamic(Dynamic d) {
132         return pool.writeIfNeeded(d);
133     }
134 
135     /**
136      * Puts a field or method descriptor into the constant pool and return its index.
137      */
138     int putDescriptor(Type t) {
139         return putName(typeSig(types.erasure(t)));
140     }

203         return pool.writeIfNeeded(new NameAndType(s.name, descriptorType(s)));
204     }
205 
206     /**
207      * Puts a package entry into the pool and returns its index.
208      */
209     int putPackage(PackageSymbol pkg) {
210         return pool.writeIfNeeded(pkg);
211     }
212 
213     /**
214      * Puts a module entry into the pool and returns its index.
215      */
216     int putModule(ModuleSymbol mod) {
217         return pool.writeIfNeeded(mod);
218     }
219 
220     /**
221      * Enter an inner class into the `innerClasses' set.
222      */
223     void enterInner(ClassSymbol c) {
224         if (c.type.isCompound()) {
225             throw new AssertionError("Unexpected intersection type: " + c.type);
226         }
227         c.complete();
228         if (c.owner.enclClass() != null && !innerClasses.contains(c)) {
229             enterInner(c.owner.enclClass());
230             innerClasses.add(c);
231         }
232     }
233 










234     /**
235      * Create a new Utf8 entry representing a descriptor for given (member) symbol.
236      */
237     private Type descriptorType(Symbol s) {
238         return s.kind == Kind.MTH ? s.externalType(types) : s.erasure(types);
239     }
240 
241     private int makeBootstrapEntry(Dynamic dynamic) {
242         BsmKey bsmKey = dynamic.bsmKey(types);
243 
244         // Figure out the index for existing BSM; create a new BSM if no key
245         Integer index = bootstrapMethods.get(bsmKey);
246         if (index == null) {
247             index = bootstrapMethods.size();
248             bootstrapMethods.put(bsmKey, index);
249         }
250 
251         return index;
252     }
253 

299             }
300         }
301 
302         @Override
303         protected void append(char ch) {
304             sigbuf.appendByte(ch);
305         }
306 
307         @Override
308         protected void append(byte[] ba) {
309             sigbuf.appendBytes(ba);
310         }
311 
312         @Override
313         protected void append(Name name) {
314             sigbuf.appendName(name);
315         }
316 
317         @Override
318         protected void classReference(ClassSymbol c) {
319             enterInner(c);
320         }
321 
322         protected void reset() {
323             sigbuf.reset();
324         }
325 
326         protected Name toName() {
327             return sigbuf.toName(names);
328         }
329     }
330 
331     class WriteablePoolHelper {
332 
333         /** Pool entries. */
334         private final Map<Object, Integer> keysToPos = new HashMap<>(64);
335 
336         final ByteBuffer poolbuf = new ByteBuffer(POOL_BUF_SIZE);
337 
338         int currentIndex = 1;
339 

345             Object key = p.poolKey(types);
346             Integer index = keysToPos.get(key);
347             if (index == null) {
348                 keysToPos.put(key, index = currentIndex++);
349                 boolean first = todo.isEmpty();
350                 todo.addLast(p);
351                 if (first) {
352                     while (!todo.isEmpty()) {
353                         writeConstant(todo.peekFirst());
354                         todo.removeFirst();
355                     }
356                 }
357             }
358             return index;
359         }
360 
361         void writeConstant(PoolConstant c) {
362             int tag = c.poolTag();
363             switch (tag) {
364                 case ClassFile.CONSTANT_Class: {
365                     Type ct = (Type)c;
366                     Name name = ct.hasTag(ARRAY) ?
367                             typeSig(ct) :
368                             names.fromUtf(externalize(ct.tsym.flatName()));
369                     poolbuf.appendByte(tag);
370                     poolbuf.appendChar(putName(name));
371                     if (ct.hasTag(CLASS)) {
372                         enterInner((ClassSymbol)ct.tsym);
373                     }
374                     break;
375                 }
376                 case ClassFile.CONSTANT_Utf8: {
377                     Name name = (Name)c;
378                     poolbuf.appendByte(tag);
379                     byte[] bs = name.toUtf();
380                     poolbuf.appendChar(bs.length);
381                     poolbuf.appendBytes(bs, 0, bs.length);
382                     if (overflowString == null && bs.length > MAX_STRING_LENGTH) {
383                         //report error only once
384                         overflowString = new String(bs);
385                     }
386                     break;
387                 }
388                 case ClassFile.CONSTANT_InterfaceMethodref:
389                 case ClassFile.CONSTANT_Methodref:
390                 case ClassFile.CONSTANT_Fieldref: {
391                     Symbol sym = (Symbol)c;
392                     poolbuf.appendByte(tag);

485     }
486 
487     /**
488      * Return signature of given type
489      */
490     private Name typeSig(Type type) {
491         signatureGen.reset();
492         signatureGen.assembleSig(type);
493         return signatureGen.toName();
494     }
495 
496     private Name classSig(Type t) {
497         signatureGen.reset();
498         List<Type> typarams = t.getTypeArguments();
499         if (typarams.nonEmpty()) {
500             signatureGen.assembleParamsSig(typarams);
501         }
502         signatureGen.assembleSig(types.supertype(t));
503         for (Type i : types.interfaces(t))
504             signatureGen.assembleSig(i);

505         return signatureGen.toName();
506     }
507 
508     void reset() {
509         innerClasses.clear();

510         bootstrapMethods.clear();
511         pool.reset();
512     }
513 }

 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 
 26 package com.sun.tools.javac.jvm;
 27 
 28 import com.sun.tools.javac.code.Kinds.Kind;
 29 import com.sun.tools.javac.code.Symbol;
 30 import com.sun.tools.javac.code.Symbol.ClassSymbol;
 31 import com.sun.tools.javac.code.Symbol.DynamicMethodSymbol;
 32 import com.sun.tools.javac.code.Symbol.MethodHandleSymbol;
 33 import com.sun.tools.javac.code.Symbol.ModuleSymbol;
 34 import com.sun.tools.javac.code.Symbol.PackageSymbol;
 35 import com.sun.tools.javac.code.Type;
 36 import com.sun.tools.javac.code.Type.ConstantPoolQType;
 37 import com.sun.tools.javac.code.Types;
 38 import com.sun.tools.javac.jvm.ClassWriter.PoolOverflow;
 39 import com.sun.tools.javac.jvm.ClassWriter.StringOverflow;
 40 import com.sun.tools.javac.jvm.PoolConstant.LoadableConstant;
 41 import com.sun.tools.javac.jvm.PoolConstant.LoadableConstant.BasicConstant;
 42 import com.sun.tools.javac.jvm.PoolConstant.Dynamic;
 43 import com.sun.tools.javac.jvm.PoolConstant.Dynamic.BsmKey;
 44 import com.sun.tools.javac.jvm.PoolConstant.NameAndType;
 45 import com.sun.tools.javac.util.ByteBuffer;
 46 import com.sun.tools.javac.util.List;
 47 import com.sun.tools.javac.util.Name;
 48 import com.sun.tools.javac.util.Names;
 49 
 50 import java.io.IOException;
 51 import java.io.OutputStream;
 52 import java.util.ArrayDeque;
 53 import java.util.HashMap;
 54 import java.util.HashSet;
 55 import java.util.LinkedHashMap;
 56 import java.util.LinkedHashSet;
 57 import java.util.Map;
 58 import java.util.Set;
 59 
 60 import static com.sun.tools.javac.code.Kinds.Kind.TYP;
 61 import static com.sun.tools.javac.code.TypeTag.ARRAY;
 62 import static com.sun.tools.javac.code.TypeTag.CLASS;
 63 import static com.sun.tools.javac.jvm.ClassFile.CONSTANT_Class;
 64 import static com.sun.tools.javac.jvm.ClassFile.CONSTANT_MethodType;
 65 import static com.sun.tools.javac.jvm.ClassFile.externalize;
 66 
 67 /**
 68  * Pool interface towards {@code ClassWriter}. Exposes methods to encode and write javac entities
 69  * into the constant pool.
 70  *
 71  *  <p><b>This is NOT part of any supported API.
 72  *  If you write code that depends on this, you do so at your own risk.
 73  *  This code and its internal interfaces are subject to change or
 74  *  deletion without notice.</b>
 75  */
 76 public class PoolWriter {
 77 
 78     /** Max number of constant pool entries. */
 79     public static final int MAX_ENTRIES = 0xFFFF;
 80 
 81     /** Max number of char in a string constant. */
 82     public static final int MAX_STRING_LENGTH = 0xFFFF;
 83 
 84     private static final int POOL_BUF_SIZE = 0x7fff;
 85 
 86     private final Types types;
 87 
 88     private final Names names;
 89 
 90     /** Pool helper **/
 91     final WriteablePoolHelper pool;
 92 
 93     /** Sole signature generator */
 94     final SharedSignatureGenerator signatureGen;
 95 
 96     /** The inner classes to be written, as an ordered set (enclosing first). */
 97     LinkedHashSet<ClassSymbol> innerClasses = new LinkedHashSet<>();
 98 
 99     Set<ClassSymbol> preloadClasses = new HashSet<>();
100 
101     /** The list of entries in the BootstrapMethods attribute. */
102     Map<BsmKey, Integer> bootstrapMethods = new LinkedHashMap<>();
103 
104     public PoolWriter(Types types, Names names) {
105         this.types = types;
106         this.names = names;
107         this.signatureGen = new SharedSignatureGenerator(types);
108         this.pool = new WriteablePoolHelper();
109     }
110 
111     /**
112      * Puts a class symbol into the pool and return its index.
113      */
114     int putClass(ClassSymbol csym) {
115         return putClass(csym.type);
116     }
117 
118     /**
119      * Puts a type into the pool and return its index. The type could be either a class, a type variable
120      * or an array type.
121      */
122     int putClass(Type t) {
123         /* Their is nothing to be gained by having the pair of class types Foo.ref and Foo.val
124            result in two different CONSTANT_Class_info strucures in the pool. These are
125            indistinguishable at the class file level. Hence we coalesce them here.
126         */
127         if (t.isReferenceProjection())
128             t = t.valueProjection();
129         return pool.writeIfNeeded(types.erasure(t));
130     }
131 
132     /**
133      * Puts a type into the pool and return its index. The type could be either a class, a type variable
134      * or an array type.
135      */
136     int putClass(ConstantPoolQType t) {
137         return pool.writeIfNeeded(t);
138     }
139 
140     /**
141      * Puts a member reference into the constant pool. Valid members are either field or method symbols.
142      */
143     int putMember(Symbol s) {
144         return pool.writeIfNeeded(s);
145     }
146 
147     /**
148      * Puts a dynamic reference into the constant pool and return its index.
149      */
150     int putDynamic(Dynamic d) {
151         return pool.writeIfNeeded(d);
152     }
153 
154     /**
155      * Puts a field or method descriptor into the constant pool and return its index.
156      */
157     int putDescriptor(Type t) {
158         return putName(typeSig(types.erasure(t)));
159     }

222         return pool.writeIfNeeded(new NameAndType(s.name, descriptorType(s)));
223     }
224 
225     /**
226      * Puts a package entry into the pool and returns its index.
227      */
228     int putPackage(PackageSymbol pkg) {
229         return pool.writeIfNeeded(pkg);
230     }
231 
232     /**
233      * Puts a module entry into the pool and returns its index.
234      */
235     int putModule(ModuleSymbol mod) {
236         return pool.writeIfNeeded(mod);
237     }
238 
239     /**
240      * Enter an inner class into the `innerClasses' set.
241      */
242     void enterInnerClass(ClassSymbol c) {
243         if (c.type.isCompound()) {
244             throw new AssertionError("Unexpected intersection type: " + c.type);
245         }
246         c.complete();
247         if (c.owner.enclClass() != null && !innerClasses.contains(c)) {
248             enterInnerClass(c.owner.enclClass());
249             innerClasses.add(c);
250         }
251     }
252 
253     /** Enter a value class into the `preloadClasses' set.
254      */
255     void enterPreloadClass(ClassSymbol c) {
256         if (c.type.isCompound()) {
257             throw new AssertionError("Unexpected intersection type: " + c.type);
258         }
259         c.complete();
260         preloadClasses.add(c);
261     }
262 
263     /**
264      * Create a new Utf8 entry representing a descriptor for given (member) symbol.
265      */
266     private Type descriptorType(Symbol s) {
267         return s.kind == Kind.MTH ? s.externalType(types) : s.erasure(types);
268     }
269 
270     private int makeBootstrapEntry(Dynamic dynamic) {
271         BsmKey bsmKey = dynamic.bsmKey(types);
272 
273         // Figure out the index for existing BSM; create a new BSM if no key
274         Integer index = bootstrapMethods.get(bsmKey);
275         if (index == null) {
276             index = bootstrapMethods.size();
277             bootstrapMethods.put(bsmKey, index);
278         }
279 
280         return index;
281     }
282 

328             }
329         }
330 
331         @Override
332         protected void append(char ch) {
333             sigbuf.appendByte(ch);
334         }
335 
336         @Override
337         protected void append(byte[] ba) {
338             sigbuf.appendBytes(ba);
339         }
340 
341         @Override
342         protected void append(Name name) {
343             sigbuf.appendName(name);
344         }
345 
346         @Override
347         protected void classReference(ClassSymbol c) {
348             enterInnerClass(c);
349         }
350 
351         protected void reset() {
352             sigbuf.reset();
353         }
354 
355         protected Name toName() {
356             return sigbuf.toName(names);
357         }
358     }
359 
360     class WriteablePoolHelper {
361 
362         /** Pool entries. */
363         private final Map<Object, Integer> keysToPos = new HashMap<>(64);
364 
365         final ByteBuffer poolbuf = new ByteBuffer(POOL_BUF_SIZE);
366 
367         int currentIndex = 1;
368 

374             Object key = p.poolKey(types);
375             Integer index = keysToPos.get(key);
376             if (index == null) {
377                 keysToPos.put(key, index = currentIndex++);
378                 boolean first = todo.isEmpty();
379                 todo.addLast(p);
380                 if (first) {
381                     while (!todo.isEmpty()) {
382                         writeConstant(todo.peekFirst());
383                         todo.removeFirst();
384                     }
385                 }
386             }
387             return index;
388         }
389 
390         void writeConstant(PoolConstant c) {
391             int tag = c.poolTag();
392             switch (tag) {
393                 case ClassFile.CONSTANT_Class: {
394                     Type ct = c instanceof ConstantPoolQType ? ((ConstantPoolQType)c).type : (Type)c;
395                     Name name = ct.hasTag(ARRAY) ?
396                             typeSig(ct) :
397                             c instanceof ConstantPoolQType ? names.fromString("Q" + new String(externalize(ct.tsym.flatName())) + ";") : names.fromUtf(externalize(ct.tsym.flatName()));
398                     poolbuf.appendByte(tag);
399                     poolbuf.appendChar(putName(name));
400                     if (ct.hasTag(CLASS)) {
401                         enterInnerClass((ClassSymbol)ct.tsym);
402                     }
403                     break;
404                 }
405                 case ClassFile.CONSTANT_Utf8: {
406                     Name name = (Name)c;
407                     poolbuf.appendByte(tag);
408                     byte[] bs = name.toUtf();
409                     poolbuf.appendChar(bs.length);
410                     poolbuf.appendBytes(bs, 0, bs.length);
411                     if (overflowString == null && bs.length > MAX_STRING_LENGTH) {
412                         //report error only once
413                         overflowString = new String(bs);
414                     }
415                     break;
416                 }
417                 case ClassFile.CONSTANT_InterfaceMethodref:
418                 case ClassFile.CONSTANT_Methodref:
419                 case ClassFile.CONSTANT_Fieldref: {
420                     Symbol sym = (Symbol)c;
421                     poolbuf.appendByte(tag);

514     }
515 
516     /**
517      * Return signature of given type
518      */
519     private Name typeSig(Type type) {
520         signatureGen.reset();
521         signatureGen.assembleSig(type);
522         return signatureGen.toName();
523     }
524 
525     private Name classSig(Type t) {
526         signatureGen.reset();
527         List<Type> typarams = t.getTypeArguments();
528         if (typarams.nonEmpty()) {
529             signatureGen.assembleParamsSig(typarams);
530         }
531         signatureGen.assembleSig(types.supertype(t));
532         for (Type i : types.interfaces(t))
533             signatureGen.assembleSig(i);
534 
535         return signatureGen.toName();
536     }
537 
538     void reset() {
539         innerClasses.clear();
540         preloadClasses.clear();
541         bootstrapMethods.clear();
542         pool.reset();
543     }
544 }
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