1 /*
  2  * Copyright (c) 2009, 2022, 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  */
 23 package jdk.vm.ci.meta;
 24 
 25 import java.lang.annotation.Annotation;
 26 import java.lang.reflect.AnnotatedElement;
 27 import java.lang.reflect.Array;
 28 import java.lang.reflect.Method;
 29 import java.lang.reflect.Modifier;
 30 import java.lang.reflect.Type;
 31 import java.util.BitSet;
 32 
 33 /**
 34  * Represents a resolved Java method. Methods, like fields and types, are resolved through
 35  * {@link ConstantPool constant pools}.
 36  */
 37 public interface ResolvedJavaMethod extends JavaMethod, InvokeTarget, ModifiersProvider, AnnotatedElement, Annotated {
 38 
 39     /**
 40      * Returns the method's bytecode. The returned bytecode does not contain breakpoints or non-Java
 41      * bytecodes. This will return {@code null} if {@link #getCodeSize()} returns {@code <= 0} or if
 42      * {@link #hasBytecodes()} returns {@code false}.
 43      *
 44      * The contained constant pool indexes may not be the ones found in the original class file but
 45      * they can be used with the JVMCI API (e.g. methods in {@link ConstantPool}).
 46      *
 47      * @return {@code null} if {@code getLinkedCodeSize() <= 0} otherwise the bytecode of the method
 48      *         whose length is guaranteed to be {@code > 0}
 49      */
 50     byte[] getCode();
 51 
 52     /**
 53      * Returns the size of the method's bytecode. If this method returns a value {@code > 0} then
 54      * {@link #getCode()} will not return {@code null}.
 55      *
 56      * @return 0 if the method has no bytecode, {@code -1} if the method does have bytecode but its
 57      *         {@linkplain #getDeclaringClass() declaring class} is not
 58      *         {@linkplain ResolvedJavaType#isLinked() linked} otherwise the size of the bytecode in
 59      *         bytes (guaranteed to be {@code > 0})
 60      */
 61     int getCodeSize();
 62 
 63     /**
 64      * Returns the {@link ResolvedJavaType} object representing the class or interface that declares
 65      * this method.
 66      */
 67     @Override
 68     ResolvedJavaType getDeclaringClass();
 69 
 70     /**
 71      * Returns the maximum number of locals used in this method's bytecodes.
 72      */
 73     int getMaxLocals();
 74 
 75     /**
 76      * Returns the maximum number of stack slots used in this method's bytecodes.
 77      */
 78     int getMaxStackSize();
 79 
 80     default boolean isFinal() {
 81         return ModifiersProvider.super.isFinalFlagSet();
 82     }
 83 
 84     /**
 85      * Determines if this method is a synthetic method as defined by the Java Language
 86      * Specification.
 87      */
 88     boolean isSynthetic();
 89 
 90     /**
 91      * Checks if the method is a varargs method.
 92      *
 93      * @return whether the method is a varargs method
 94      * @jvms 4.6
 95      */
 96     boolean isVarArgs();
 97 
 98     /**
 99      * Checks if the method is a bridge method.
100      *
101      * @return whether the method is a bridge method
102      * @jvms 4.6
103      */
104     boolean isBridge();
105 
106     /**
107      * Returns {@code true} if this method is a default method; returns {@code false} otherwise.
108      *
109      * A default method is a public non-abstract instance method, that is, a non-static method with
110      * a body, declared in an interface type.
111      *
112      * @return true if and only if this method is a default method as defined by the Java Language
113      *         Specification.
114      */
115     boolean isDefault();
116 
117     /**
118      * Checks whether this method is a class initializer.
119      *
120      * @return {@code true} if the method is a class initializer
121      */
122     boolean isClassInitializer();
123 
124     /**
125      * Checks whether this method is a constructor.
126      *
127      * @return {@code true} if the method is a constructor
128      */
129     boolean isConstructor();
130 
131     /**
132      * Checks whether this method can be statically bound (usually, that means it is final or
133      * private or static, but not abstract, or the declaring class is final).
134      *
135      * @return {@code true} if this method can be statically bound
136      */
137     boolean canBeStaticallyBound();
138 
139     /**
140      * Returns the list of exception handlers for this method.
141      */
142     ExceptionHandler[] getExceptionHandlers();
143 
144     /**
145      * Returns a stack trace element for this method and a given bytecode index.
146      */
147     StackTraceElement asStackTraceElement(int bci);
148 
149     /**
150      * Returns an object that provides access to the profiling information recorded for this method.
151      */
152     default ProfilingInfo getProfilingInfo() {
153         return getProfilingInfo(true, true);
154     }
155 
156     /**
157      * Returns an object that provides access to the profiling information recorded for this method.
158      *
159      * @param includeNormal if true,
160      *            {@linkplain ProfilingInfo#getDeoptimizationCount(DeoptimizationReason)
161      *            deoptimization counts} will include deoptimization that happened during execution
162      *            of standard non-osr methods.
163      * @param includeOSR if true,
164      *            {@linkplain ProfilingInfo#getDeoptimizationCount(DeoptimizationReason)
165      *            deoptimization counts} will include deoptimization that happened during execution
166      *            of on-stack-replacement methods.
167      */
168     ProfilingInfo getProfilingInfo(boolean includeNormal, boolean includeOSR);
169 
170     /**
171      * Invalidates the profiling information and restarts profiling upon the next invocation.
172      */
173     void reprofile();
174 
175     /**
176      * Returns the constant pool of this method.
177      */
178     ConstantPool getConstantPool();
179 
180     /**
181      * A {@code Parameter} provides information about method parameters.
182      */
183     class Parameter implements AnnotatedElement {
184         private final String name;
185         private final ResolvedJavaMethod method;
186         private final int modifiers;
187         private final int index;
188 
189         /**
190          * Constructor for {@code Parameter}.
191          *
192          * @param name the name of the parameter or {@code null} if there is no
193          *            {@literal MethodParameters} class file attribute providing a non-empty name
194          *            for the parameter
195          * @param modifiers the modifier flags for the parameter
196          * @param method the method which defines this parameter
197          * @param index the index of the parameter
198          */
199         public Parameter(String name,
200                         int modifiers,
201                         ResolvedJavaMethod method,
202                         int index) {
203             assert name == null || !name.isEmpty();
204             this.name = name;
205             this.modifiers = modifiers;
206             this.method = method;
207             this.index = index;
208         }
209 
210         /**
211          * Gets the name of the parameter. If the parameter's name is {@linkplain #isNamePresent()
212          * present}, then this method returns the name provided by the class file. Otherwise, this
213          * method synthesizes a name of the form argN, where N is the index of the parameter in the
214          * descriptor of the method which declares the parameter.
215          *
216          * @return the name of the parameter, either provided by the class file or synthesized if
217          *         the class file does not provide a name
218          */
219         public String getName() {
220             if (name == null) {
221                 return "arg" + index;
222             } else {
223                 return name;
224             }
225         }
226 
227         /**
228          * Gets the method declaring the parameter.
229          */
230         public ResolvedJavaMethod getDeclaringMethod() {
231             return method;
232         }
233 
234         /**
235          * Get the modifier flags for the parameter.
236          */
237         public int getModifiers() {
238             return modifiers;
239         }
240 
241         /**
242          * Gets the kind of the parameter.
243          */
244         public JavaKind getKind() {
245             return method.getSignature().getParameterKind(index);
246         }
247 
248         /**
249          * Gets the formal type of the parameter.
250          */
251         public Type getParameterizedType() {
252             return method.getGenericParameterTypes()[index];
253         }
254 
255         /**
256          * Gets the type of the parameter.
257          */
258         public JavaType getType() {
259             return method.getSignature().getParameterType(index, method.getDeclaringClass());
260         }
261 
262         /**
263          * Determines if the parameter has a name according to a {@literal MethodParameters} class
264          * file attribute.
265          *
266          * @return true if and only if the parameter has a name according to the class file.
267          */
268         public boolean isNamePresent() {
269             return name != null;
270         }
271 
272         /**
273          * Determines if the parameter represents a variable argument list.
274          */
275         public boolean isVarArgs() {
276             return method.isVarArgs() && index == method.getSignature().getParameterCount(false) - 1;
277         }
278 
279         @Override
280         public <T extends Annotation> T getAnnotation(Class<T> annotationClass) {
281             return method.getParameterAnnotations(annotationClass)[index];
282         }
283 
284         @Override
285         public Annotation[] getAnnotations() {
286             return method.getParameterAnnotations()[index];
287         }
288 
289         @Override
290         public Annotation[] getDeclaredAnnotations() {
291             return getAnnotations();
292         }
293 
294         @Override
295         public String toString() {
296             Type type = getParameterizedType();
297             String typename = type.getTypeName();
298             if (isVarArgs()) {
299                 typename = typename.replaceFirst("\\[\\]$", "...");
300             }
301 
302             final StringBuilder sb = new StringBuilder(Modifier.toString(getModifiers()));
303             if (sb.length() != 0) {
304                 sb.append(' ');
305             }
306             return sb.append(typename).append(' ').append(getName()).toString();
307         }
308 
309         @Override
310         public boolean equals(Object obj) {
311             if (obj instanceof Parameter) {
312                 Parameter other = (Parameter) obj;
313                 return (other.method.equals(method) && other.index == index);
314             }
315             return false;
316         }
317 
318         @Override
319         public int hashCode() {
320             return method.hashCode() ^ index;
321         }
322     }
323 
324     /**
325      * Returns an array of {@code Parameter} objects that represent all the parameters to this
326      * method. Returns an array of length 0 if this method has no parameters. Returns {@code null}
327      * if the parameter information is unavailable.
328      */
329     default Parameter[] getParameters() {
330         return null;
331     }
332 
333     /**
334      * Returns an array of arrays that represent the annotations on the formal parameters, in
335      * declaration order, of this method.
336      *
337      * @see Method#getParameterAnnotations()
338      */
339     Annotation[][] getParameterAnnotations();
340 
341     /**
342      * Returns an array of {@link Type} objects that represent the formal parameter types, in
343      * declaration order, of this method.
344      *
345      * @see Method#getGenericParameterTypes()
346      */
347     Type[] getGenericParameterTypes();
348 
349     /**
350      * Returns {@code true} if this method is not excluded from inlining and has associated Java
351      * bytecodes (@see {@link ResolvedJavaMethod#hasBytecodes()}).
352      */
353     boolean canBeInlined();
354 
355     /**
356      * Determines if this method is targeted by a VM directive (e.g.,
357      * {@code -XX:CompileCommand=dontinline,<pattern>}) or VM recognized annotation (e.g.,
358      * {@code jdk.internal.vm.annotation.DontInline}) that specifies it should not be inlined.
359      */
360     boolean hasNeverInlineDirective();
361 
362     /**
363      * Returns {@code true} if the inlining of this method should be forced.
364      */
365     boolean shouldBeInlined();
366 
367     /**
368      * Returns the LineNumberTable of this method or null if this method does not have a line
369      * numbers table.
370      */
371     LineNumberTable getLineNumberTable();
372 
373     /**
374      * Returns the local variable table of this method or null if this method does not have a local
375      * variable table.
376      */
377     LocalVariableTable getLocalVariableTable();
378 
379     /**
380      * Gets the encoding of (that is, a constant representing the value of) this method.
381      *
382      * @return a constant representing a reference to this method
383      */
384     Constant getEncoding();
385 
386     /**
387      * Checks if this method is present in the virtual table for subtypes of the specified
388      * {@linkplain ResolvedJavaType type}.
389      *
390      * @return true is this method is present in the virtual table for subtypes of this type.
391      */
392     boolean isInVirtualMethodTable(ResolvedJavaType resolved);
393 
394     /**
395      * Gets the annotation of a particular type for a formal parameter of this method.
396      *
397      * @param annotationClass the Class object corresponding to the annotation type
398      * @param parameterIndex the index of a formal parameter of {@code method}
399      * @return the annotation of type {@code annotationClass} for the formal parameter present, else
400      *         null
401      * @throws IndexOutOfBoundsException if {@code parameterIndex} does not denote a formal
402      *             parameter
403      */
404     default <T extends Annotation> T getParameterAnnotation(Class<T> annotationClass, int parameterIndex) {
405         if (parameterIndex >= 0) {
406             Annotation[][] parameterAnnotations = getParameterAnnotations();
407             for (Annotation a : parameterAnnotations[parameterIndex]) {
408                 if (a.annotationType() == annotationClass) {
409                     return annotationClass.cast(a);
410                 }
411             }
412         }
413         return null;
414     }
415 
416     default JavaType[] toParameterTypes() {
417         JavaType receiver = isStatic() || isConstructor() ? null : getDeclaringClass();
418         return getSignature().toParameterTypes(receiver);
419     }
420 
421     /**
422      * Gets the annotations of a particular type for the formal parameters of this method.
423      *
424      * @param annotationClass the Class object corresponding to the annotation type
425      * @return the annotation of type {@code annotationClass} (if any) for each formal parameter
426      *         present
427      */
428     @SuppressWarnings("unchecked")
429     default <T extends Annotation> T[] getParameterAnnotations(Class<T> annotationClass) {
430         Annotation[][] parameterAnnotations = getParameterAnnotations();
431         T[] result = (T[]) Array.newInstance(annotationClass, parameterAnnotations.length);
432         for (int i = 0; i < parameterAnnotations.length; i++) {
433             for (Annotation a : parameterAnnotations[i]) {
434                 if (a.annotationType() == annotationClass) {
435                     result[i] = annotationClass.cast(a);
436                 }
437             }
438         }
439         return result;
440     }
441 
442     /**
443      * @see #getCodeSize()
444      * @return {@code getCodeSize() > 0}
445      */
446     default boolean hasBytecodes() {
447         return getCodeSize() > 0;
448     }
449 
450     /**
451      * Checks whether the method has a receiver parameter - i.e., whether it is not static.
452      *
453      * @return whether the method has a receiver parameter
454      */
455     default boolean hasReceiver() {
456         return !isStatic();
457     }
458 
459     /**
460      * Determines if this method is {@link java.lang.Object#Object()}.
461      */
462     default boolean isJavaLangObjectInit() {
463         return getDeclaringClass().isJavaLangObject() && (getName().equals("<init>") || getName().equals("<vnew>"));
464     }
465 
466     /**
467      * Gets a speculation log that can be used when compiling this method to make new speculations
468      * and query previously failed speculations. The implementation may return a new
469      * {@link SpeculationLog} object each time this method is called so its the caller's
470      * responsibility to ensure the same speculation log is used throughout a compilation.
471      */
472     SpeculationLog getSpeculationLog();
473 }