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