1 /*
2 * Copyright (c) 2000, 2013, 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_RUNTIME_VMSTRUCTS_HPP
26 #define SHARE_VM_RUNTIME_VMSTRUCTS_HPP
27
28 #include "utilities/debug.hpp"
29 #ifdef COMPILER1
30 #include "c1/c1_Runtime1.hpp"
31 #endif
32
33 // This table encapsulates the debugging information required by the
34 // serviceability agent in order to run. Specifically, we need to
35 // understand the layout of certain C data structures (offsets, in
36 // bytes, of their fields.)
37 //
38 // There are alternatives for the design of this mechanism, including
39 // parsing platform-specific debugging symbols from a debug build into
40 // a program database. While this current mechanism can be considered
41 // to be a workaround for the inability to debug arbitrary C and C++
42 // programs at the present time, it does have certain advantages.
43 // First, it is platform-independent, which will vastly simplify the
44 // initial bringup of the system both now and on future platforms.
45 // Second, it is embedded within the VM, as opposed to being in a
46 // separate program database; experience has shown that whenever
47 // portions of a system are decoupled, version skew is problematic.
48 // Third, generating a program database, for example for a product
49 // build, would probably require two builds to be done: the desired
50 // product build as well as an intermediary build with the PRODUCT
51 // flag turned on but also compiled with -g, leading to a doubling of
52 // the time required to get a serviceability agent-debuggable product
53 // build. Fourth, and very significantly, this table probably
54 // preserves more information about field types than stabs do; for
55 // example, it preserves the fact that a field is a "jlong" rather
56 // than transforming the type according to the typedef in jni_md.h,
57 // which allows the Java-side code to identify "Java-sized" fields in
58 // C++ data structures. If the symbol parsing mechanism was redone
59 // using stabs, it might still be necessary to have a table somewhere
60 // containing this information.
61 //
62 // Do not change the sizes or signedness of the integer values in
63 // these data structures; they are fixed over in the serviceability
64 // agent's Java code (for bootstrapping).
65
66 typedef struct {
67 const char* typeName; // The type name containing the given field (example: "Klass")
68 const char* fieldName; // The field name within the type (example: "_name")
69 const char* typeString; // Quoted name of the type of this field (example: "Symbol*";
70 // parsed in Java to ensure type correctness
71 int32_t isStatic; // Indicates whether following field is an offset or an address
72 uint64_t offset; // Offset of field within structure; only used for nonstatic fields
73 void* address; // Address of field; only used for static fields
74 // ("offset" can not be reused because of apparent SparcWorks compiler bug
75 // in generation of initializer data)
76 } VMStructEntry;
77
78 typedef struct {
79 const char* typeName; // Type name (example: "Method")
80 const char* superclassName; // Superclass name, or null if none (example: "oopDesc")
81 int32_t isOopType; // Does this type represent an oop typedef? (i.e., "Method*" or
82 // "Klass*", but NOT "Method")
83 int32_t isIntegerType; // Does this type represent an integer type (of arbitrary size)?
84 int32_t isUnsigned; // If so, is it unsigned?
85 uint64_t size; // Size, in bytes, of the type
86 } VMTypeEntry;
87
88 typedef struct {
89 const char* name; // Name of constant (example: "_thread_in_native")
90 int32_t value; // Value of constant
91 } VMIntConstantEntry;
92
93 typedef struct {
94 const char* name; // Name of constant (example: "_thread_in_native")
95 uint64_t value; // Value of constant
96 } VMLongConstantEntry;
97
98 typedef struct {
99 const char* name; // Name of address (example: "SharedRuntime::register_finalizer")
100 void* value; // Value of address
101 } VMAddressEntry;
102
103 // This class is a friend of most classes, to be able to access
104 // private fields
105 class VMStructs {
106 public:
107 // The last entry is identified over in the serviceability agent by
108 // the fact that it has a NULL fieldName
109 static VMStructEntry localHotSpotVMStructs[];
110
111 // The last entry is identified over in the serviceability agent by
112 // the fact that it has a NULL typeName
113 static VMTypeEntry localHotSpotVMTypes[];
114
115 // Table of integer constants required by the serviceability agent.
116 // The last entry is identified over in the serviceability agent by
117 // the fact that it has a NULL typeName
118 static VMIntConstantEntry localHotSpotVMIntConstants[];
119
120 // Table of long constants required by the serviceability agent.
121 // The last entry is identified over in the serviceability agent by
122 // the fact that it has a NULL typeName
123 static VMLongConstantEntry localHotSpotVMLongConstants[];
124
125 /**
126 * Table of addresses.
127 */
128 static VMAddressEntry localHotSpotVMAddresses[];
129
130 // This is used to run any checking code necessary for validation of
131 // the data structure (debug build only)
132 static void init();
133
134 #ifndef PRODUCT
135 // Execute unit tests
136 static void test();
137 #endif
138
139 private:
140 // Look up a type in localHotSpotVMTypes using strcmp() (debug build only).
141 // Returns 1 if found, 0 if not.
142 // debug_only(static int findType(const char* typeName);)
143 static int findType(const char* typeName);
144 };
145
146 #endif // SHARE_VM_RUNTIME_VMSTRUCTS_HPP