1 /*
   2  * Copyright (c) 1997, 2010, 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 #ifndef SHARE_VM_CODE_PCDESC_HPP
  26 #define SHARE_VM_CODE_PCDESC_HPP
  27 
  28 #include "memory/allocation.hpp"
  29 
  30 // PcDescs map a physical PC (given as offset from start of nmethod) to
  31 // the corresponding source scope and byte code index.
  32 
  33 class nmethod;
  34 
  35 class PcDesc VALUE_OBJ_CLASS_SPEC {
  36   friend class VMStructs;
  37  private:
  38   int _pc_offset;           // offset from start of nmethod
  39   int _scope_decode_offset; // offset for scope in nmethod
  40   int _obj_decode_offset;
  41 
  42   enum {
  43     PCDESC_reexecute               = 1 << 0,
  44     PCDESC_is_method_handle_invoke = 1 << 1,
  45     PCDESC_return_oop              = 1 << 2
  46   };
  47 
  48   int _flags;
  49 
  50   void set_flag(int mask, bool z) {
  51     _flags = z ? (_flags | mask) : (_flags & ~mask);
  52   }
  53 
  54  public:
  55   int pc_offset() const           { return _pc_offset;   }
  56   int scope_decode_offset() const { return _scope_decode_offset; }
  57   int obj_decode_offset() const   { return _obj_decode_offset; }
  58 
  59   void set_pc_offset(int x)           { _pc_offset           = x; }
  60   void set_scope_decode_offset(int x) { _scope_decode_offset = x; }
  61   void set_obj_decode_offset(int x)   { _obj_decode_offset   = x; }
  62 
  63   // Constructor (only used for static in nmethod.cpp)
  64   // Also used by ScopeDesc::sender()]
  65   PcDesc(int pc_offset, int scope_decode_offset, int obj_decode_offset);
  66 
  67   enum {
  68     // upper and lower exclusive limits real offsets:
  69     lower_offset_limit = -1,
  70     upper_offset_limit = (unsigned int)-1 >> 1
  71   };
  72 
  73   // Flags
  74   bool     should_reexecute()              const { return (_flags & PCDESC_reexecute) != 0; }
  75   void set_should_reexecute(bool z)              { set_flag(PCDESC_reexecute, z); }
  76 
  77   // Does pd refer to the same information as pd?
  78   bool is_same_info(const PcDesc* pd) {
  79     return _scope_decode_offset == pd->_scope_decode_offset &&
  80       _obj_decode_offset == pd->_obj_decode_offset &&
  81       _flags == pd->_flags;
  82   }
  83 
  84   bool     is_method_handle_invoke()       const { return (_flags & PCDESC_is_method_handle_invoke) != 0;     }
  85   void set_is_method_handle_invoke(bool z)       { set_flag(PCDESC_is_method_handle_invoke, z); }
  86 
  87   bool     return_oop()                    const { return (_flags & PCDESC_return_oop) != 0;     }
  88   void set_return_oop(bool z)                    { set_flag(PCDESC_return_oop, z); }
  89 
  90   // Returns the real pc
  91   address real_pc(const nmethod* code) const;
  92 
  93   void print(nmethod* code);
  94   bool verify(nmethod* code);
  95 };
  96 
  97 #endif // SHARE_VM_CODE_PCDESC_HPP