1 /*
2 * Copyright (c) 2002, 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
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
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23 */
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 #include "utilities/macros.hpp"
31
32 class JavaThread;
33
34 //
35 // RegisterMap
36 //
37 // A companion structure used for stack traversal. The RegisterMap contains
38 // misc. information needed in order to do correct stack traversal of stack
39 // frames. Hence, it must always be passed in as an argument to
40 // frame::sender(RegisterMap*).
41 //
42 // In particular,
43 // 1) It provides access to the thread for which the stack belongs. The
44 // thread object is needed in order to get sender of a deoptimized frame.
45 //
46 // 2) It is used to pass information from a callee frame to its caller
47 // frame about how the frame should be traversed. This is used to let
48 // the caller frame take care of calling oops-do of out-going
49 // arguments, when the callee frame is not instantiated yet. This
50 // happens, e.g., when a compiled frame calls into
51 // resolve_virtual_call. (Hence, it is critical that the same
52 // RegisterMap object is used for the entire stack walk. Normally,
53 // this is hidden by using the StackFrameStream.) This is used when
54 // doing follow_oops and oops_do.
55 //
56 // 3) The RegisterMap keeps track of the values of callee-saved registers
57 // from frame to frame (hence, the name). For some stack traversal the
58 // values of the callee-saved registers does not matter, e.g., if you
59 // only need the static properties such as frame type, pc, and such.
60 // Updating of the RegisterMap can be turned off by instantiating the
61 // register map as: RegisterMap map(thread, false);
62
63 class RegisterMap : public StackObj {
64 public:
65 typedef julong LocationValidType;
66 enum {
67 reg_count = ConcreteRegisterImpl::number_of_registers,
68 location_valid_type_size = sizeof(LocationValidType)*8,
69 location_valid_size = (reg_count+location_valid_type_size-1)/location_valid_type_size
70 };
71 private:
72 intptr_t* _location[reg_count]; // Location of registers (intptr_t* looks better than address in the debugger)
73 LocationValidType _location_valid[location_valid_size];
74 bool _include_argument_oops; // Should include argument_oop marked locations for compiler
75 JavaThread* _thread; // Reference to current thread
76 bool _update_map; // Tells if the register map need to be
77 // updated when traversing the stack
78
79 #ifdef ASSERT
80 void check_location_valid();
81 #else
82 void check_location_valid() {}
83 #endif
84
85 public:
86 debug_only(intptr_t* _update_for_id;) // Assert that RegisterMap is not updated twice for same frame
87 RegisterMap(JavaThread *thread, bool update_map = true);
88 RegisterMap(const RegisterMap* map);
89
90 address location(VMReg reg) const {
91 int index = reg->value() / location_valid_type_size;
92 assert(0 <= reg->value() && reg->value() < reg_count, "range check");
93 assert(0 <= index && index < location_valid_size, "range check");
94 if (_location_valid[index] & ((LocationValidType)1 << (reg->value() % location_valid_type_size))) {
95 return (address) _location[reg->value()];
96 } else {
97 return pd_location(reg);
98 }
99 }
100
101 void set_location(VMReg reg, address loc) {
102 int index = reg->value() / location_valid_type_size;
103 assert(0 <= reg->value() && reg->value() < reg_count, "range check");
104 assert(0 <= index && index < location_valid_size, "range check");
105 assert(_update_map, "updating map that does not need updating");
106 _location[reg->value()] = (intptr_t*) loc;
107 _location_valid[index] |= ((LocationValidType)1 << (reg->value() % location_valid_type_size));
108 check_location_valid();
109 }
110
111 // Called by an entry frame.
112 void clear();
113
114 bool include_argument_oops() const { return _include_argument_oops; }
115 void set_include_argument_oops(bool f) { _include_argument_oops = f; }
116
117 JavaThread *thread() const { return _thread; }
118 bool update_map() const { return _update_map; }
119
120 void print_on(outputStream* st) const;
121 void print() const;
122
123 // the following contains the definition of pd_xxx methods
124 #include CPU_HEADER(registerMap)
125
126 };
127
128 #endif // SHARE_VM_RUNTIME_REGISTERMAP_HPP