1 /*
   2  * Copyright (c) 2002, 2014, 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_RUNTIME_REGISTERMAP_HPP
  26 #define SHARE_VM_RUNTIME_REGISTERMAP_HPP
  27 
  28 #include "code/vmreg.hpp"
  29 #include "utilities/globalDefinitions.hpp"
  30 
  31 class JavaThread;
  32 
  33 //
  34 // RegisterMap
  35 //
  36 // A companion structure used for stack traversal. The RegisterMap contains
  37 // misc. information needed in order to do correct stack traversal of stack
  38 // frames.  Hence, it must always be passed in as an argument to
  39 // frame::sender(RegisterMap*).
  40 //
  41 // In particular,
  42 //   1) It provides access to the thread for which the stack belongs.  The
  43 //      thread object is needed in order to get sender of a deoptimized frame.
  44 //
  45 //   2) It is used to pass information from a callee frame to its caller
  46 //      frame about how the frame should be traversed.  This is used to let
  47 //      the caller frame take care of calling oops-do of out-going
  48 //      arguments, when the callee frame is not instantiated yet.  This
  49 //      happens, e.g., when a compiled frame calls into
  50 //      resolve_virtual_call.  (Hence, it is critical that the same
  51 //      RegisterMap object is used for the entire stack walk.  Normally,
  52 //      this is hidden by using the StackFrameStream.)  This is used when
  53 //      doing follow_oops and oops_do.
  54 //
  55 //   3) The RegisterMap keeps track of the values of callee-saved registers
  56 //      from frame to frame (hence, the name).  For some stack traversal the
  57 //      values of the callee-saved registers does not matter, e.g., if you
  58 //      only need the static properties such as frame type, pc, and such.
  59 //      Updating of the RegisterMap can be turned off by instantiating the
  60 //      register map as: RegisterMap map(thread, false);
  61 
  62 class RegisterMap : public StackObj {
  63  public:
  64     typedef julong LocationValidType;
  65   enum {
  66     reg_count = ConcreteRegisterImpl::number_of_registers,
  67     location_valid_type_size = sizeof(LocationValidType)*8,
  68     location_valid_size = (reg_count+location_valid_type_size-1)/location_valid_type_size
  69   };
  70  private:
  71   intptr_t*    _location[reg_count];    // Location of registers (intptr_t* looks better than address in the debugger)
  72   LocationValidType _location_valid[location_valid_size];
  73   bool        _include_argument_oops;   // Should include argument_oop marked locations for compiler
  74   JavaThread* _thread;                  // Reference to current thread
  75   bool        _update_map;              // Tells if the register map need to be
  76                                         // updated when traversing the stack
  77 
  78 #ifdef ASSERT
  79   void check_location_valid();
  80 #else
  81   void check_location_valid() {}
  82 #endif
  83 
  84  public:
  85   debug_only(intptr_t* _update_for_id;) // Assert that RegisterMap is not updated twice for same frame
  86   RegisterMap(JavaThread *thread, bool update_map = true);
  87   RegisterMap(const RegisterMap* map);
  88 
  89   address location(VMReg reg) const {
  90     int index = reg->value() / location_valid_type_size;
  91     assert(0 <= reg->value() && reg->value() < reg_count, "range check");
  92     assert(0 <= index && index < location_valid_size, "range check");
  93     if (_location_valid[index] & ((LocationValidType)1 << (reg->value() % location_valid_type_size))) {
  94       return (address) _location[reg->value()];
  95     } else {
  96       return pd_location(reg);
  97     }
  98   }
  99 
 100   void set_location(VMReg reg, address loc) {
 101     int index = reg->value() / location_valid_type_size;
 102     assert(0 <= reg->value() && reg->value() < reg_count, "range check");
 103     assert(0 <= index && index < location_valid_size, "range check");
 104     assert(_update_map, "updating map that does not need updating");
 105     _location[reg->value()] = (intptr_t*) loc;
 106     _location_valid[index] |= ((LocationValidType)1 << (reg->value() % location_valid_type_size));
 107     check_location_valid();
 108   }
 109 
 110   // Called by an entry frame.
 111   void clear();
 112 
 113   bool include_argument_oops() const      { return _include_argument_oops; }
 114   void set_include_argument_oops(bool f)  { _include_argument_oops = f; }
 115 
 116   JavaThread *thread() const { return _thread; }
 117   bool update_map()    const { return _update_map; }
 118 
 119   void print_on(outputStream* st) const;
 120   void print() const;
 121 
 122   // the following contains the definition of pd_xxx methods
 123 #ifdef TARGET_ARCH_x86
 124 # include "registerMap_x86.hpp"
 125 #endif
 126 #ifdef TARGET_ARCH_sparc
 127 # include "registerMap_sparc.hpp"
 128 #endif
 129 #ifdef TARGET_ARCH_zero
 130 # include "registerMap_zero.hpp"
 131 #endif
 132 #ifdef TARGET_ARCH_arm
 133 # include "registerMap_arm.hpp"
 134 #endif
 135 #ifdef TARGET_ARCH_ppc
 136 # include "registerMap_ppc.hpp"
 137 #endif
 138 
 139 };
 140 
 141 #endif // SHARE_VM_RUNTIME_REGISTERMAP_HPP