1 /*
   2  * Copyright (c) 1997, 2016, 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
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  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
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  24 
  25 #ifndef SHARE_VM_CODE_SCOPEDESC_HPP
  26 #define SHARE_VM_CODE_SCOPEDESC_HPP
  27 
  28 #include "code/debugInfo.hpp"
  29 #include "code/pcDesc.hpp"
  30 #include "oops/method.hpp"
  31 #include "utilities/growableArray.hpp"
  32 
  33 // SimpleScopeDesc is used when all you need to extract from
  34 // a given pc,nmethod pair is a Method* and a bci. This is
  35 // quite a bit faster than allocating a full ScopeDesc, but
  36 // very limited in abilities.
  37 
  38 class SimpleScopeDesc : public StackObj {
  39  private:
  40   Method* _method;
  41   int _bci;
  42 
  43  public:
  44   SimpleScopeDesc(CompiledMethod* code, address pc) {
  45     PcDesc* pc_desc = code->pc_desc_at(pc);
  46     assert(pc_desc != NULL, "Must be able to find matching PcDesc");
  47     DebugInfoReadStream buffer(code, pc_desc->scope_decode_offset());
  48     int ignore_sender = buffer.read_int();
  49     _method           = buffer.read_method();
  50     _bci              = buffer.read_bci();
  51   }
  52 
  53   Method* method() { return _method; }
  54   int bci() { return _bci; }
  55 };
  56 
  57 // ScopeDescs contain the information that makes source-level debugging of
  58 // nmethods possible; each scopeDesc describes a method activation
  59 
  60 class ScopeDesc : public ResourceObj {
  61  public:
  62   // Constructor
  63   ScopeDesc(const CompiledMethod* code, int decode_offset, int obj_decode_offset, bool reexecute, bool rethrow_exception, bool return_oop);
  64 
  65   // Calls above, giving default value of "serialized_null" to the
  66   // "obj_decode_offset" argument.  (We don't use a default argument to
  67   // avoid a .hpp-.hpp dependency.)
  68   ScopeDesc(const CompiledMethod* code, int decode_offset, bool reexecute, bool rethrow_exception, bool return_oop);
  69 
  70   // Direct access to scope
  71   ScopeDesc* at_offset(int decode_offset) { return new ScopeDesc(this, decode_offset); }
  72 
  73   // JVM state
  74   Method* method()      const { return _method; }
  75   int          bci()      const { return _bci;    }
  76   bool should_reexecute() const { return _reexecute; }
  77   bool rethrow_exception() const { return _rethrow_exception; }
  78   bool return_oop()       const { return _return_oop; }
  79 
  80   GrowableArray<ScopeValue*>*   locals();
  81   GrowableArray<ScopeValue*>*   expressions();
  82   GrowableArray<MonitorValue*>* monitors();
  83   GrowableArray<ScopeValue*>*   objects();
  84 
  85   // Stack walking, returns NULL if this is the outer most scope.
  86   ScopeDesc* sender() const;
  87 
  88   // Returns where the scope was decoded
  89   int decode_offset() const { return _decode_offset; }
  90 
  91   int sender_decode_offset() const { return _sender_decode_offset; }
  92 
  93   // Tells whether sender() returns NULL
  94   bool is_top() const;
  95 
  96  private:
  97   void initialize(const ScopeDesc* parent, int decode_offset);
  98   // Alternative constructors
  99   ScopeDesc(const ScopeDesc* parent);
 100   ScopeDesc(const ScopeDesc* parent, int decode_offset);
 101 
 102   // JVM state
 103   Method*       _method;
 104   int           _bci;
 105   bool          _reexecute;
 106   bool          _rethrow_exception;
 107   bool          _return_oop;
 108 
 109   // Decoding offsets
 110   int _decode_offset;
 111   int _sender_decode_offset;
 112   int _locals_decode_offset;
 113   int _expressions_decode_offset;
 114   int _monitors_decode_offset;
 115 
 116   // Object pool
 117   GrowableArray<ScopeValue*>* _objects;
 118 
 119   // Nmethod information
 120   const CompiledMethod* _code;
 121 
 122   // Decoding operations
 123   void decode_body();
 124   GrowableArray<ScopeValue*>* decode_scope_values(int decode_offset);
 125   GrowableArray<MonitorValue*>* decode_monitor_values(int decode_offset);
 126   GrowableArray<ScopeValue*>* decode_object_values(int decode_offset);
 127 
 128   DebugInfoReadStream* stream_at(int decode_offset) const;
 129 
 130 
 131  public:
 132   // Verification
 133   void verify();
 134 
 135 #ifndef PRODUCT
 136  public:
 137   // Printing support
 138   void print_on(outputStream* st) const;
 139   void print_on(outputStream* st, PcDesc* pd) const;
 140   void print_value_on(outputStream* st) const;
 141 #endif
 142 };
 143 
 144 #endif // SHARE_VM_CODE_SCOPEDESC_HPP