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     _bci              = buffer.read_bci();
  43   }
  44 
  45   methodOop method() { return _method; }
  46   int bci() { return _bci; }
  47 };
  48 
  49 // ScopeDescs contain the information that makes source-level debugging of
  50 // nmethods possible; each scopeDesc describes a method activation
  51 
  52 class ScopeDesc : public ResourceObj {
  53  public:
  54   // Constructor
  55   ScopeDesc(const nmethod* code, int decode_offset, int obj_decode_offset);
  56 
  57   // Calls above, giving default value of "serialized_null" to the
  58   // "obj_decode_offset" argument.  (We don't use a default argument to
  59   // avoid a .hpp-.hpp dependency.)
  60   ScopeDesc(const nmethod* code, int decode_offset);
  61 
  62   // JVM state
  63   methodHandle method() const { return _method; }
  64   int          bci()    const { return _bci;    }
  65 
  66   GrowableArray<ScopeValue*>*   locals();
  67   GrowableArray<ScopeValue*>*   expressions();
  68   GrowableArray<MonitorValue*>* monitors();
  69   GrowableArray<ScopeValue*>*   objects();
  70 
  71   // Stack walking, returns NULL if this is the outer most scope.
  72   ScopeDesc* sender() const;
  73 
  74   // Returns where the scope was decoded
  75   int decode_offset() const { return _decode_offset; }
  76 
  77   // Tells whether sender() returns NULL
  78   bool is_top() const;
  79   // Tells whether sd is equal to this
  80   bool is_equal(ScopeDesc* sd) const;
  81 
  82  private:
  83   // Alternative constructor
  84   ScopeDesc(const ScopeDesc* parent);
  85 
  86   // JVM state
  87   methodHandle  _method;
  88   int           _bci;
  89 
  90   // Decoding offsets
  91   int _decode_offset;
  92   int _sender_decode_offset;
  93   int _locals_decode_offset;
  94   int _expressions_decode_offset;
  95   int _monitors_decode_offset;
  96 
  97   // Object pool
  98   GrowableArray<ScopeValue*>* _objects;
  99 
 100   // Nmethod information
 101   const nmethod* _code;
 102 
 103   // Decoding operations
 104   void decode_body();
 105   GrowableArray<ScopeValue*>* decode_scope_values(int decode_offset);
 106   GrowableArray<MonitorValue*>* decode_monitor_values(int decode_offset);
 107   GrowableArray<ScopeValue*>* decode_object_values(int decode_offset);
 108 
 109   DebugInfoReadStream* stream_at(int decode_offset) const;
 110 
 111 
 112  public:
 113   // Verification
 114   void verify();
 115 
 116 #ifndef PRODUCT
 117  public:
 118   // Printing support
 119   void print_on(outputStream* st) const;
 120   void print_on(outputStream* st, PcDesc* pd) const;
 121   void print_value_on(outputStream* st) const;
 122 #endif
 123 };