1 /*
   2  * Copyright 1997-2006 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  20  * CA 95054 USA or visit www.sun.com if you need additional information or
  21  * have any questions.
  22  *
  23  */
  24 
  25 // SimpleScopeDesc is used when all you need to extract from
  26 // a given pc,nmethod pair is a methodOop and a bci. This is
  27 // quite a bit faster than allocating a full ScopeDesc, but
  28 // very limited in abilities.
  29 
  30 class SimpleScopeDesc : public StackObj {
  31  private:
  32   methodOop _method;
  33   int _bci;
  34 
  35  public:
  36   SimpleScopeDesc(nmethod* code,address pc) {
  37     PcDesc* pc_desc = code->pc_desc_at(pc);
  38     assert(pc_desc != NULL, "Must be able to find matching PcDesc");
  39     DebugInfoReadStream buffer(code, pc_desc->scope_decode_offset());
  40     int ignore_sender = buffer.read_int();
  41     _method           = methodOop(buffer.read_oop());
  42     bool dummy_reexecute; //only methodOop and bci are needed!
  43     _bci              = buffer.read_bci_and_reexecute(dummy_reexecute);
  44   }
  45 
  46   methodOop method() { return _method; }
  47   int bci() { return _bci; }
  48 };
  49 
  50 // ScopeDescs contain the information that makes source-level debugging of
  51 // nmethods possible; each scopeDesc describes a method activation
  52 
  53 class ScopeDesc : public ResourceObj {
  54  public:
  55   // Constructor
  56   ScopeDesc(const nmethod* code, int decode_offset, int obj_decode_offset);
  57 
  58   // Calls above, giving default value of "serialized_null" to the
  59   // "obj_decode_offset" argument.  (We don't use a default argument to
  60   // avoid a .hpp-.hpp dependency.)
  61   ScopeDesc(const nmethod* code, int decode_offset);
  62 
  63   // JVM state
  64   methodHandle method()   const { return _method; }
  65   int          bci()      const { return _bci;    }
  66   bool should_reexecute() const { return _reexecute; }
  67 
  68   GrowableArray<ScopeValue*>*   locals();
  69   GrowableArray<ScopeValue*>*   expressions();
  70   GrowableArray<MonitorValue*>* monitors();
  71   GrowableArray<ScopeValue*>*   objects();
  72 
  73   // Stack walking, returns NULL if this is the outer most scope.
  74   ScopeDesc* sender() const;
  75 
  76   // Returns where the scope was decoded
  77   int decode_offset() const { return _decode_offset; }
  78 
  79   // Tells whether sender() returns NULL
  80   bool is_top() const;
  81   // Tells whether sd is equal to this
  82   bool is_equal(ScopeDesc* sd) const;
  83 
  84  private:
  85   // Alternative constructor
  86   ScopeDesc(const ScopeDesc* parent);
  87 
  88   // JVM state
  89   methodHandle  _method;
  90   int           _bci;
  91   bool          _reexecute;
  92 
  93   // Decoding offsets
  94   int _decode_offset;
  95   int _sender_decode_offset;
  96   int _locals_decode_offset;
  97   int _expressions_decode_offset;
  98   int _monitors_decode_offset;
  99 
 100   // Object pool
 101   GrowableArray<ScopeValue*>* _objects;
 102 
 103   // Nmethod information
 104   const nmethod* _code;
 105 
 106   // Decoding operations
 107   void decode_body();
 108   GrowableArray<ScopeValue*>* decode_scope_values(int decode_offset);
 109   GrowableArray<MonitorValue*>* decode_monitor_values(int decode_offset);
 110   GrowableArray<ScopeValue*>* decode_object_values(int decode_offset);
 111 
 112   DebugInfoReadStream* stream_at(int decode_offset) const;
 113 
 114 
 115  public:
 116   // Verification
 117   void verify();
 118 
 119 #ifndef PRODUCT
 120  public:
 121   // Printing support
 122   void print_on(outputStream* st) const;
 123   void print_on(outputStream* st, PcDesc* pd) const;
 124   void print_value_on(outputStream* st) const;
 125 #endif
 126 };