1 /*
  2  * Copyright (c) 1997, 2022, 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.
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 23  */
 24 
 25 #ifndef SHARE_CODE_PCDESC_HPP
 26 #define SHARE_CODE_PCDESC_HPP
 27 
 28 
 29 // PcDescs map a physical PC (given as offset from start of nmethod) to
 30 // the corresponding source scope and byte code index.
 31 
 32 class CompiledMethod;
 33 
 34 class PcDesc {
 35   friend class VMStructs;
 36  private:
 37   int _pc_offset;           // offset from start of nmethod
 38   int _scope_decode_offset; // offset for scope in nmethod
 39   int _obj_decode_offset;
 40 
 41   enum {
 42     PCDESC_reexecute                 = 1 << 0,
 43     PCDESC_is_method_handle_invoke   = 1 << 1,
 44     PCDESC_return_oop                = 1 << 2,
 45     PCDESC_rethrow_exception         = 1 << 3,
 46     PCDESC_has_ea_local_in_scope     = 1 << 4,
 47     PCDESC_arg_escape                = 1 << 5
 48   };
 49 
 50   int _flags;
 51 
 52   void set_flag(int mask, bool z) {
 53     _flags = z ? (_flags | mask) : (_flags & ~mask);
 54   }
 55 
 56  public:
 57   int pc_offset() const           { return _pc_offset;   }
 58   int scope_decode_offset() const { return _scope_decode_offset; }
 59   int obj_decode_offset() const   { return _obj_decode_offset; }
 60 
 61   void set_pc_offset(int x)           { _pc_offset           = x; }
 62   void set_scope_decode_offset(int x) { _scope_decode_offset = x; }
 63   void set_obj_decode_offset(int x)   { _obj_decode_offset   = x; }
 64 
 65   // Constructor (only used for static in nmethod.cpp)
 66   // Also used by ScopeDesc::sender()]
 67   PcDesc(int pc_offset, int scope_decode_offset, int obj_decode_offset);
 68 
 69   enum {
 70     // upper and lower exclusive limits real offsets:
 71     lower_offset_limit = -1,
 72     upper_offset_limit = (unsigned int)-1 >> 1
 73   };
 74 
 75   // Flags
 76   bool     rethrow_exception()              const { return (_flags & PCDESC_rethrow_exception) != 0; }
 77   void set_rethrow_exception(bool z)              { set_flag(PCDESC_rethrow_exception, z); }
 78   bool     should_reexecute()              const { return (_flags & PCDESC_reexecute) != 0; }
 79   void set_should_reexecute(bool z)              { set_flag(PCDESC_reexecute, z); }
 80 
 81   // Does pd refer to the same information as pd?
 82   bool is_same_info(const PcDesc* pd) {
 83     return _scope_decode_offset == pd->_scope_decode_offset &&
 84       _obj_decode_offset == pd->_obj_decode_offset &&
 85       _flags == pd->_flags;
 86   }
 87 
 88   bool     is_method_handle_invoke()       const { return (_flags & PCDESC_is_method_handle_invoke) != 0;     }
 89   void set_is_method_handle_invoke(bool z)       { set_flag(PCDESC_is_method_handle_invoke, z); }
 90 
 91   bool     return_oop()                    const { return (_flags & PCDESC_return_oop) != 0;     }
 92   void set_return_oop(bool z)                    { set_flag(PCDESC_return_oop, z); }
 93 
 94   // Indicates if there are objects in scope that, based on escape analysis, are local to the
 95   // compiled method or local to the current thread, i.e. NoEscape or ArgEscape
 96   bool     has_ea_local_in_scope()         const { return (_flags & PCDESC_has_ea_local_in_scope) != 0; }
 97   void set_has_ea_local_in_scope(bool z)         { set_flag(PCDESC_has_ea_local_in_scope, z); }
 98 
 99   // Indicates if this pc descriptor is at a call site where objects that do not escape the
100   // current thread are passed as arguments.
101   bool     arg_escape()                    const { return (_flags & PCDESC_arg_escape) != 0; }
102   void set_arg_escape(bool z)                    { set_flag(PCDESC_arg_escape, z); }
103 
104   // Returns the real pc
105   address real_pc(const CompiledMethod* code) const;
106 
107   void print(CompiledMethod* code) { print_on(tty, code); }
108   void print_on(outputStream* st, CompiledMethod* code);
109   bool verify(CompiledMethod* code);
110 };
111 
112 #endif // SHARE_CODE_PCDESC_HPP