1 /*
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  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.
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 23  */
 24 
 25 package sun.jvm.hotspot.runtime;
 26 
 27 import java.util.*;
 28 import sun.jvm.hotspot.code.*;
 29 import sun.jvm.hotspot.debugger.*;
 30 import sun.jvm.hotspot.oops.*;
 31 import sun.jvm.hotspot.utilities.*;
 32 
 33 /** FIXME: missing many accessors; all we have right now is the method
 34     and BCI. NOTE that this has been modified from the VM's version to
 35     handle NULL ScopeDescs for the debugging case. This simplifies
 36     using code a great deal. */
 37 
 38 public class CompiledVFrame extends JavaVFrame {
 39   private ScopeDesc scope;
 40   private boolean mayBeImprecise;
 41 
 42   public CompiledVFrame(Frame fr, RegisterMap regMap, JavaThread thread, ScopeDesc scope, boolean mayBeImprecise) {
 43     super(fr, regMap, thread);
 44     this.scope = scope;
 45     this.mayBeImprecise = mayBeImprecise;
 46     if (!VM.getVM().isDebugging()) {
 47       Assert.that(scope != null, "scope must be present");
 48     }
 49   }
 50 
 51   public boolean isTop() {
 52     if (VM.getVM().isDebugging()) {
 53       return (getScope() == null || getScope().isTop());
 54     } else {
 55       return getScope().isTop();
 56     }
 57   }
 58 
 59   public boolean isCompiledFrame() {
 60     return true;
 61   }
 62 
 63   public boolean isDeoptimized() {
 64     return fr.isDeoptimized();
 65   }
 66 
 67   public boolean mayBeImpreciseDbg() {
 68     return mayBeImprecise;
 69   }
 70 
 71   /** Returns the active method */
 72   public NMethod getCode() {
 73     return VM.getVM().getCodeCache().findNMethod(fr.getPC());
 74   }
 75 
 76   /** Returns the active method. Does not perform a guarantee
 77       regarding unloaded methods -- more suitable for debugging
 78       system. */
 79   public NMethod getCodeUnsafe() {
 80     return VM.getVM().getCodeCache().findNMethodUnsafe(fr.getPC());
 81   }
 82 
 83   /** Returns the ScopeDesc */
 84   public ScopeDesc getScope() {
 85     return scope;
 86   }
 87 
 88   public Method getMethod() {
 89     if (VM.getVM().isDebugging() && getScope() == null) {
 90       return getCodeUnsafe().getMethod();
 91     }
 92     return getScope().getMethod();
 93   }
 94 
 95   public StackValueCollection getLocals() {
 96     if (getScope() == null)
 97       return new StackValueCollection();
 98     List<ScopeValue> scvList = getScope().getLocals();
 99     if (scvList == null)
100       return new StackValueCollection();
101 
102     // scvList is the list of ScopeValues describing the JVM stack state.
103     // There is one scv_list entry for every JVM stack state in use.
104     int length = scvList.size();
105     StackValueCollection result = new StackValueCollection(length);
106     for( int i = 0; i < length; i++ )
107       result.add( createStackValue(scvList.get(i)) );
108 
109     return result;
110   }
111 
112   public StackValueCollection getExpressions() {
113     if (getScope() == null)
114       return new StackValueCollection();
115     List<ScopeValue> scvList = getScope().getExpressions();
116     if (scvList == null)
117       return new StackValueCollection();
118 
119     // scvList is the list of ScopeValues describing the JVM stack state.
120     // There is one scv_list entry for every JVM stack state in use.
121     int length = scvList.size();
122     StackValueCollection result = new StackValueCollection(length);
123     for( int i = 0; i < length; i++ )
124       result.add( createStackValue(scvList.get(i)) );
125 
126     return result;
127   }
128 
129   public List<MonitorInfo> getMonitors() {
130     if (getScope() == null) {
131       return new ArrayList<>();
132     }
133     List<MonitorValue> monitors = getScope().getMonitors();
134     if (monitors == null) {
135       return new ArrayList<>();
136     }
137     List<MonitorInfo> result = new ArrayList<>(monitors.size());
138     for (int i = 0; i < monitors.size(); i++) {
139       MonitorValue mv = monitors.get(i);
140       ScopeValue ov = mv.owner();
141       StackValue ownerSV = createStackValue(ov); // it is an oop
142       if (ov.isObject()) { // The owner object was scalar replaced
143         Assert.that(mv.eliminated() && ownerSV.objIsScalarReplaced(), "monitor should be eliminated for scalar replaced object");
144         // Put klass for scalar replaced object.
145         ScopeValue kv = ((ObjectValue)ov).getKlass();
146         Assert.that(kv.isConstantOop(), "klass should be oop constant for scalar replaced object");
147         OopHandle k = ((ConstantOopReadValue)kv).getValue();
148         result.add(new MonitorInfo(k, resolveMonitorLock(mv.basicLock()), mv.eliminated(), true));
149       } else {
150         result.add(new MonitorInfo(ownerSV.getObject(), resolveMonitorLock(mv.basicLock()), mv.eliminated(), false));
151       }
152     }
153     return result;
154   }
155 
156   public int getBCI() {
157     int raw = getRawBCI();
158     return ((raw == DebugInformationRecorder.SYNCHRONIZATION_ENTRY_BCI) ? 0 : raw);
159   }
160 
161   /** Returns SynchronizationEntryBCI or bci() (used for synchronization) */
162   public int getRawBCI() {
163     if (VM.getVM().isDebugging() && getScope() == null) {
164       return 0; // No debugging information!
165     }
166     return getScope().getBCI();
167   }
168 
169   /** Returns the sender vframe */
170   public VFrame sender() {
171     if (Assert.ASSERTS_ENABLED) {
172       Assert.that(isTop(), "just checking");
173     }
174     return sender(false);
175   }
176 
177   public VFrame sender(boolean mayBeImprecise) {
178     if (!VM.getVM().isDebugging()) {
179       if (Assert.ASSERTS_ENABLED) {
180         Assert.that(scope != null, "When new stub generator is in place, then scope can never be NULL");
181       }
182     }
183     Frame f = (Frame) getFrame().clone();
184     return (isTop()
185               ? super.sender(false)
186               : new CompiledVFrame(f, getRegisterMap(), getThread(), getScope().sender(), mayBeImprecise));
187   }
188 
189   private StackValue createStackValue(ScopeValue sv) {
190     // FIXME: this code appears to be out-of-date with respect to the VM especially in 64-bit mode
191     if (sv.isLocation()) {
192       // Stack or register value
193       Location loc = ((LocationValue) sv).getLocation();
194 
195       if (loc.isIllegal()) return new StackValue();
196 
197       // First find address of value
198       Address valueAddr = loc.isRegister()
199         // Value was in a callee-save register
200         ? getRegisterMap().getLocation(new VMReg(loc.getRegisterNumber()))
201         // Else value was directly saved on the stack. The frame's original stack pointer,
202         // before any extension by its callee (due to Compiler1 linkage on SPARC), must be used.
203         : fr.getUnextendedSP().addOffsetTo(loc.getStackOffset());
204 
205       // Then package it right depending on type
206       if (loc.holdsFloat()) {    // Holds a float in a double register?
207         // The callee has no clue whether the register holds a float,
208         // double or is unused.  He always saves a double.  Here we know
209         // a double was saved, but we only want a float back.  Narrow the
210         // saved double to the float that the JVM wants.
211         if (Assert.ASSERTS_ENABLED) {
212           Assert.that( loc.isRegister(), "floats always saved to stack in 1 word" );
213         }
214         float value = (float) valueAddr.getJDoubleAt(0);
215         return new StackValue(Float.floatToIntBits(value) & 0xFFFFFFFF); // 64-bit high half is stack junk
216       } else if (loc.holdsInt()) {  // Holds an int in a long register?
217         // The callee has no clue whether the register holds an int,
218         // long or is unused.  He always saves a long.  Here we know
219         // a long was saved, but we only want an int back.  Narrow the
220         // saved long to the int that the JVM wants.
221         if (Assert.ASSERTS_ENABLED) {
222           Assert.that( loc.isRegister(), "ints always saved to stack in 1 word" );
223         }
224         return new StackValue(valueAddr.getJLongAt(0) & 0xFFFFFFFF);
225       } else if (loc.holdsNarrowOop()) {  // Holds an narrow oop?
226         if (loc.isRegister() && VM.getVM().isBigEndian()) {
227           // The callee has no clue whether the register holds an narrow oop,
228           // long or is unused.  He always saves a long.  Here we know
229           // a long was saved, but we only want an narrow oop back.  Narrow the
230           // saved long to the narrow oop that the JVM wants.
231           return new StackValue(valueAddr.getCompOopHandleAt(VM.getVM().getIntSize()), 0);
232         } else {
233           return new StackValue(valueAddr.getCompOopHandleAt(0), 0);
234         }
235       } else if( loc.holdsOop() ) {  // Holds an oop?
236         return new StackValue(valueAddr.getOopHandleAt(0), 0);
237       } else if( loc.holdsDouble() ) {
238         // Double value in a single stack slot
239         return new StackValue(valueAddr.getJIntAt(0) & 0xFFFFFFFF);
240       } else if(loc.holdsAddr()) {
241         if (Assert.ASSERTS_ENABLED) {
242           Assert.that(!VM.getVM().isServerCompiler(), "No address type for locations with C2 (jsr-s are inlined)");
243         }
244         // FIXME: not yet implemented (no access to safepoint state yet)
245         return new StackValue(0);
246         //      intptr_t return_addr_tmp = *(intptr_t *)value_addr;
247         //      int bci = -1;
248         //      // Get the bci of the jsr that generated this returnAddress value.
249         //      // If the destination of a jsr is a block that ends with a return or throw, then
250         //      // the GraphBuilder converts the jsr into a direct goto.  This has the side effect that
251         //      // the return address for the jsr gets emitted as a bci instead of as a real pc
252         //      if (code()->contains((address)return_addr_tmp)) {
253         //        ScopeDesc* scope = code()->scope_desc_at((address)(return_addr_tmp - jsr_call_offset), false);
254         //        bci = scope->bci();
255         //      } else {
256         //        bci = (int)return_addr_tmp;
257         //      }
258         //      // no need to lock method as this happens at Safepoint
259         //      assert (SafepointSynchronize::is_at_safepoint(), "must be at safepoint, otherwise lock method()");
260         //      // make sure bci points to jsr
261         //      Bytecode* bytecode = Bytecode_at(method()->bcp_from(bci));
262         //      Bytecodes::Code bc = bytecode->code();
263         //      assert (bc == Bytecodes::_jsr || bc == Bytecodes::_jsr_w, "must be jsr");
264         //
265         //      // the real returnAddress is the bytecode following the jsr
266         //      return new StackValue((intptr_t)(bci + Bytecodes::length_for(bc)));
267       } else if (VM.getVM().isLP64() && loc.holdsLong()) {
268         if ( loc.isRegister() ) {
269           // Long value in two registers, high half in the first, low in the second
270           return new StackValue(((valueAddr.getJLongAt(0) & 0xFFFFFFFF) << 32) |
271                                 ((valueAddr.getJLongAt(8) & 0xFFFFFFFF)));
272         } else {
273           // Long value in a single stack slot
274           return new StackValue(valueAddr.getJLongAt(0));
275         }
276       } else if( loc.isRegister() ) {
277         // At the moment, all non-oop values in registers are 4 bytes,
278         // including double and long halves (see Compile::FillLocArray() in
279         // opto/output.cpp).  Haul them out as such and return a StackValue
280         // containing an image of the value as it appears in a stack slot.
281         // If this is a double or long half, the interpreter _must_ deal
282         // with doubles and longs as entities split across two stack slots.
283         // To change this so doubles and/or longs can live in one stack slot,
284         // a StackValue will have to understand that it can contain an
285         // undivided double or long, implying that a Location (and the debug
286         // info mechanism) and FillLocArray() will also have to understand it.
287         return new StackValue(valueAddr.getJIntAt(0) & 0xFFFFFFFF);
288       } else {
289         return new StackValue(valueAddr.getJIntAt(0) & 0xFFFFFFFF);
290       }
291     } else if (sv.isConstantInt()) {
292       // Constant int: treat same as register int.
293       return new StackValue(((ConstantIntValue) sv).getValue() & 0xFFFFFFFF);
294     } else if (sv.isConstantOop()) {
295       // constant oop
296       return new StackValue(((ConstantOopReadValue) sv).getValue(), 0);
297     } else if (sv.isConstantDouble()) {
298       // Constant double in a single stack slot
299       double d = ((ConstantDoubleValue) sv).getValue();
300       return new StackValue(Double.doubleToLongBits(d) & 0xFFFFFFFF);
301     } else if (VM.getVM().isLP64() && sv.isConstantLong()) {
302       // Constant long in a single stack slot
303       return new StackValue(((ConstantLongValue) sv).getValue() & 0xFFFFFFFF);
304     } else if (sv.isObject()) {
305       // Scalar replaced object in compiled frame
306       return new StackValue(((ObjectValue)sv).getValue(), 1);
307     }
308 
309     // Unknown ScopeValue type
310     Assert.that(false, "Should not reach here");
311     return new StackValue(0);   // dummy
312   }
313 
314   private BasicLock resolveMonitorLock(Location location) {
315     if (Assert.ASSERTS_ENABLED) {
316       Assert.that(location.isStack(), "for now we only look at the stack");
317     }
318     int byteOffset = location.getStackOffset();
319     // (stack picture)
320     // high: [     ]  byte_offset + wordSize
321     // low   [     ]  byte_offset
322     //
323     // sp->  [     ]  0
324     // the byte_offset is the distance from the stack pointer to the lowest address
325     // The frame's original stack pointer, before any extension by its callee
326     // (due to Compiler1 linkage on SPARC), must be used.
327     return new BasicLock(getFrame().getUnextendedSP().addOffsetTo(byteOffset));
328   }
329 }