1 /*
  2  * Copyright (c) 2000, 2025, 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  */
 24 
 25 package sun.jvm.hotspot.oops;
 26 
 27 import java.io.PrintStream;
 28 import sun.jvm.hotspot.utilities.Observable;
 29 import sun.jvm.hotspot.utilities.Observer;
 30 import sun.jvm.hotspot.utilities.U1Array;
 31 
 32 import sun.jvm.hotspot.code.NMethod;
 33 import sun.jvm.hotspot.debugger.Address;
 34 import sun.jvm.hotspot.interpreter.OopMapCacheEntry;
 35 import sun.jvm.hotspot.runtime.SignatureConverter;
 36 import sun.jvm.hotspot.runtime.VM;
 37 import sun.jvm.hotspot.runtime.VMObjectFactory;
 38 import sun.jvm.hotspot.types.AddressField;
 39 import sun.jvm.hotspot.types.Type;
 40 import sun.jvm.hotspot.types.TypeDataBase;
 41 import sun.jvm.hotspot.types.WrongTypeException;
 42 import sun.jvm.hotspot.utilities.Assert;
 43 import sun.jvm.hotspot.utilities.U1Array;
 44 
 45 // A Method represents a Java method
 46 
 47 public class Method extends Metadata {
 48   static {
 49     VM.registerVMInitializedObserver(new Observer() {
 50         public void update(Observable o, Object data) {
 51           initialize(VM.getVM().getTypeDataBase());
 52         }
 53       });
 54   }
 55 
 56   private static synchronized void initialize(TypeDataBase db) throws WrongTypeException {
 57     type                       = db.lookupType("Method");
 58     constMethod                = type.getAddressField("_constMethod");
 59     methodData                 = type.getAddressField("_method_data");
 60     methodCounters             = type.getAddressField("_method_counters");
 61     accessFlags                = new CIntField(type.getCIntegerField("_access_flags"), 0);
 62     code                       = type.getAddressField("_code");
 63     vtableIndex                = new CIntField(type.getCIntegerField("_vtable_index"), 0);
 64 
 65     /*
 66     fromCompiledCodeEntryPoint = type.getAddressField("_from_compiled_code_entry_point");
 67     interpreterEntry           = type.getAddressField("_from_interpreted_entry");
 68     */
 69 
 70     objectInitializerName = null;
 71     classInitializerName = null;
 72   }
 73 
 74   public Method(Address addr) {
 75     super(addr);
 76   }
 77 
 78   public boolean isMethod()            { return true; }
 79 
 80   // Not a Method field, used to keep type.
 81   private static Type type;
 82 
 83   // Fields
 84   private static AddressField  constMethod;
 85   private static AddressField  methodData;
 86   private static AddressField  methodCounters;
 87   private static CIntField accessFlags;
 88   private static CIntField vtableIndex;
 89 
 90   private static AddressField       code;
 91   /*
 92   private static AddressCField      fromCompiledCodeEntryPoint;
 93   private static AddressField       interpreterEntry;
 94   */
 95 
 96 
 97   // constant method names - <init>, <clinit>
 98   // Initialized lazily to avoid initialization ordering dependencies between ArrayKlass and String
 99   private static String objectInitializerName;
100   private static String classInitializerName;
101   private static String objectInitializerName() {
102     if (objectInitializerName == null) {
103       objectInitializerName = "<init>";
104     }
105     return objectInitializerName;
106   }
107 
108   private static String classInitializerName() {
109     if (classInitializerName == null) {
110       classInitializerName = "<clinit>";
111     }
112     return classInitializerName;
113   }
114 
115 
116   // Accessors for declared fields
117   public ConstMethod  getConstMethod()                {
118     Address addr = constMethod.getValue(getAddress());
119     return VMObjectFactory.newObject(ConstMethod.class, addr);
120   }
121   public ConstantPool getConstants()                  {
122     return getConstMethod().getConstants();
123   }
124   public boolean      hasStackMapTable()              {
125     return getConstMethod().hasStackMapTable();
126   }
127   public U1Array      getStackMapData()               {
128     return getConstMethod().getStackMapData();
129   }
130   public MethodData   getMethodData()                 {
131     Address addr = methodData.getValue(getAddress());
132     return VMObjectFactory.newObject(MethodData.class, addr);
133   }
134   public MethodCounters getMethodCounters()           {
135     Address addr = methodCounters.getValue(getAddress());
136     return VMObjectFactory.newObject(MethodCounters.class, addr);
137   }
138   /** WARNING: this is in words, not useful in this system; use getObjectSize() instead */
139   public long         getMaxStack()                   { return                getConstMethod().getMaxStack();   }
140   public long         getMaxLocals()                  { return                getConstMethod().getMaxLocals();         }
141   public long         getSizeOfParameters()           { return                getConstMethod().getSizeOfParameters();  }
142   public long         getNameIndex()                  { return                getConstMethod().getNameIndex();  }
143   public long         getSignatureIndex()             { return            getConstMethod().getSignatureIndex(); }
144   public long         getGenericSignatureIndex()      { return     getConstMethod().getGenericSignatureIndex(); }
145   public long         getAccessFlags()                { return                accessFlags.getValue(this);       }
146   public long         getCodeSize()                   { return                getConstMethod().getCodeSize();   }
147   public long         getVtableIndex()                { return                vtableIndex.getValue(this);       }
148   public long         getInvocationCount()          {
149     MethodCounters mc = getMethodCounters();
150     return mc == null ? 0 : mc.getInvocationCounter();
151   }
152   public long         getBackedgeCount()          {
153     MethodCounters mc = getMethodCounters();
154     return mc == null ? 0 : mc.getBackedgeCounter();
155   }
156 
157   // get associated compiled native method, if available, else return null.
158   public NMethod getNativeMethod() {
159     Address addr = code.getValue(getAddress());
160     return VMObjectFactory.newObject(NMethod.class, addr);
161   }
162 
163   // Convenience routine
164   public AccessFlags getAccessFlagsObj() {
165     return new AccessFlags(getAccessFlags());
166   }
167 
168   /** Get a bytecode or breakpoint at the given bci */
169   public int getBytecodeOrBPAt(int bci) {
170     return getConstMethod().getBytecodeOrBPAt(bci);
171   }
172 
173   /** Fetch the original non-breakpoint bytecode at the specified
174       bci. It is required that there is currently a bytecode at this
175       bci. */
176   public int getOrigBytecodeAt(int bci) {
177     BreakpointInfo bp = getMethodHolder().getBreakpoints();
178     for (; bp != null; bp = bp.getNext()) {
179       if (bp.match(this, bci)) {
180         return bp.getOrigBytecode();
181       }
182     }
183     System.err.println("Requested bci " + bci);
184     for (; bp != null; bp = bp.getNext()) {
185       System.err.println("Breakpoint at bci " + bp.getBCI() + ", bytecode " +
186                          bp.getOrigBytecode());
187     }
188     Assert.that(false, "Should not reach here");
189     return -1; // not reached
190   }
191 
192   public byte getBytecodeByteArg(int bci) {
193     return getConstMethod().getBytecodeByteArg(bci);
194   }
195 
196   /** Fetches a 16-bit big-endian ("Java ordered") value from the
197       bytecode stream */
198   public short getBytecodeShortArg(int bci) {
199     return getConstMethod().getBytecodeShortArg(bci);
200   }
201 
202   /** Fetches a 16-bit native ordered value from the
203       bytecode stream */
204   public short getNativeShortArg(int bci) {
205     return getConstMethod().getNativeShortArg(bci);
206   }
207 
208   /** Fetches a 32-bit big-endian ("Java ordered") value from the
209       bytecode stream */
210   public int getBytecodeIntArg(int bci) {
211     return getConstMethod().getBytecodeIntArg(bci);
212   }
213 
214   /** Fetches a 32-bit native ordered value from the
215       bytecode stream */
216   public int getNativeIntArg(int bci) {
217     return getConstMethod().getNativeIntArg(bci);
218   }
219 
220   public byte[] getByteCode() {
221     return getConstMethod().getByteCode();
222   }
223 
224   /*
225   public Address      getCode()                       { return codeField.getValue(this); }
226   public Address      getInterpreterEntry()           { return interpreterEntryField.getValue(this); }
227   public Address      getFromCompiledCodeEntryPoint() { return fromCompiledCodeEntryPointField.getValue(this); }
228   */
229   // Accessors
230   public Symbol  getName()          { return getConstants().getSymbolAt(getNameIndex());         }
231   public Symbol  getSignature()     { return getConstants().getSymbolAt(getSignatureIndex());    }
232   public Symbol  getGenericSignature() {
233      long index = getGenericSignatureIndex();
234      return (index != 0L) ? getConstants().getSymbolAt(index) : null;
235   }
236 
237   // Method holder (the Klass holding this method)
238   public InstanceKlass   getMethodHolder()  { return getConstants().getPoolHolder();                   }
239 
240   // Access flags
241   public boolean isPublic()         { return getAccessFlagsObj().isPublic();                           }
242   public boolean isPrivate()        { return getAccessFlagsObj().isPrivate();                          }
243   public boolean isProtected()      { return getAccessFlagsObj().isProtected();                        }
244   public boolean isPackagePrivate() { AccessFlags af = getAccessFlagsObj();
245                                       return (!af.isPublic() && !af.isPrivate() && !af.isProtected()); }
246   public boolean isStatic()         { return getAccessFlagsObj().isStatic();                           }
247   public boolean isFinal()          { return getAccessFlagsObj().isFinal();                            }
248   public boolean isSynchronized()   { return getAccessFlagsObj().isSynchronized();                     }
249   public boolean isBridge()         { return getAccessFlagsObj().isBridge();                           }
250   public boolean isVarArgs()        { return getAccessFlagsObj().isVarArgs();                          }
251   public boolean isNative()         { return getAccessFlagsObj().isNative();                           }
252   public boolean isAbstract()       { return getAccessFlagsObj().isAbstract();                         }
253   public boolean isStrict()         { return getAccessFlagsObj().isStrict();                           }
254   public boolean isSynthetic()      { return getAccessFlagsObj().isSynthetic();                        }
255 
256   public boolean isConstructor() {
257      return (!isStatic()) && getName().equals(objectInitializerName());
258   }
259 
260   public boolean isStaticInitializer() {
261      return isStatic() && getName().equals(classInitializerName());
262   }
263 
264   public OopMapCacheEntry getMaskFor(int bci) {
265     OopMapCacheEntry entry = new OopMapCacheEntry();
266     entry.fill(this, bci);
267     return entry;
268   }
269 
270   public long getSize() {
271     return type.getSize() + (isNative() ? 2: 0);
272   }
273 
274   public void printValueOn(PrintStream tty) {
275       tty.print("Method " + getMethodHolder().getName().asString() + "." +
276                 getName().asString() + getSignature().asString() + "@" + getAddress());
277   }
278 
279   public void iterateFields(MetadataVisitor visitor) {
280       visitor.doCInt(accessFlags, true);
281     }
282 
283   public boolean hasLineNumberTable() {
284     return getConstMethod().hasLineNumberTable();
285   }
286 
287   public int getLineNumberFromBCI(int bci) {
288     return getConstMethod().getLineNumberFromBCI(bci);
289   }
290 
291   public LineNumberTableElement[] getLineNumberTable() {
292     return getConstMethod().getLineNumberTable();
293   }
294 
295   public boolean hasLocalVariableTable() {
296     return getConstMethod().hasLocalVariableTable();
297   }
298 
299   /** Should only be called if table is present */
300   public LocalVariableTableElement[] getLocalVariableTable() {
301     return getConstMethod().getLocalVariableTable();
302   }
303 
304   public Symbol getLocalVariableName(int bci, int slot) {
305     if (! hasLocalVariableTable()) {
306        return null;
307     }
308 
309     LocalVariableTableElement[] locals = getLocalVariableTable();
310     for (int l = 0; l < locals.length; l++) {
311        LocalVariableTableElement local = locals[l];
312        if ((bci >= local.getStartBCI()) &&
313           (bci < (local.getStartBCI() + local.getLength())) &&
314           slot == local.getSlot()) {
315           return getConstants().getSymbolAt(local.getNameCPIndex());
316        }
317     }
318 
319     return null;
320   }
321 
322   public boolean hasExceptionTable() {
323     return getConstMethod().hasExceptionTable();
324   }
325 
326   public ExceptionTableElement[] getExceptionTable() {
327     return getConstMethod().getExceptionTable();
328   }
329 
330   public boolean hasCheckedExceptions() {
331     return getConstMethod().hasCheckedExceptions();
332   }
333 
334   /** Should only be called if table is present */
335   public CheckedExceptionElement[] getCheckedExceptions() {
336     return getConstMethod().getCheckedExceptions();
337   }
338 
339   /** Returns name and signature in external form for debugging
340       purposes */
341   public String externalNameAndSignature() {
342     final StringBuffer buf = new StringBuffer();
343     buf.append(getMethodHolder().getName().asString());
344     buf.append(".");
345     buf.append(getName().asString());
346     buf.append("(");
347     new SignatureConverter(getSignature(), buf).iterateParameters();
348     buf.append(")");
349     return buf.toString().replace('/', '.');
350   }
351 
352   public int interpreterThrowoutCount() {
353     return getMethodCounters().interpreterThrowoutCount();
354   }
355 
356   public long interpreterInvocationCount() {
357     return getInvocationCount();
358   }
359 
360   public String nameAsAscii() {
361     return getMethodHolder().getName().asString() + " " +
362       OopUtilities.escapeString(getName().asString()) + " " +
363       getSignature().asString();
364   }
365 
366   public U1Array getAnnotations() {
367     return getConstMethod().getMethodAnnotations();
368   }
369 
370   public U1Array getParameterAnnotations() {
371     return getConstMethod().getParameterAnnotations();
372   }
373 
374   public U1Array getTypeAnnotations() {
375     return getConstMethod().getTypeAnnotations();
376   }
377 
378   public U1Array getAnnotationDefault() {
379     return getConstMethod().getDefaultAnnotations();
380   }
381 }