1/*
2 * Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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5 * This code is free software; you can redistribute it and/or modify it
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7 * published by the Free Software Foundation.
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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).
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24
25#ifndef SHARE_RUNTIME_VMSTRUCTS_HPP
26#define SHARE_RUNTIME_VMSTRUCTS_HPP
27
28#include "utilities/debug.hpp"
29#include "utilities/globalDefinitions.hpp"
30#ifdef COMPILER1
31#include "c1/c1_Runtime1.hpp"
32#endif
33
34// This table encapsulates the debugging information required by the
35// serviceability agent in order to run. Specifically, we need to
36// understand the layout of certain C data structures (offsets, in
37// bytes, of their fields.)
38//
39// There are alternatives for the design of this mechanism, including
40// parsing platform-specific debugging symbols from a debug build into
41// a program database. While this current mechanism can be considered
42// to be a workaround for the inability to debug arbitrary C and C++
43// programs at the present time, it does have certain advantages.
44// First, it is platform-independent, which will vastly simplify the
45// initial bringup of the system both now and on future platforms.
46// Second, it is embedded within the VM, as opposed to being in a
47// separate program database; experience has shown that whenever
48// portions of a system are decoupled, version skew is problematic.
49// Third, generating a program database, for example for a product
50// build, would probably require two builds to be done: the desired
51// product build as well as an intermediary build with the PRODUCT
52// flag turned on but also compiled with -g, leading to a doubling of
53// the time required to get a serviceability agent-debuggable product
54// build. Fourth, and very significantly, this table probably
55// preserves more information about field types than stabs do; for
56// example, it preserves the fact that a field is a "jlong" rather
57// than transforming the type according to the typedef in jni_md.h,
58// which allows the Java-side code to identify "Java-sized" fields in
59// C++ data structures. If the symbol parsing mechanism was redone
60// using stabs, it might still be necessary to have a table somewhere
61// containing this information.
62//
63// Do not change the sizes or signedness of the integer values in
64// these data structures; they are fixed over in the serviceability
65// agent's Java code (for bootstrapping).
66
67typedef struct {
68 const char* typeName; // The type name containing the given field (example: "Klass")
69 const char* fieldName; // The field name within the type (example: "_name")
70 const char* typeString; // Quoted name of the type of this field (example: "Symbol*";
71 // parsed in Java to ensure type correctness
72 int32_t isStatic; // Indicates whether following field is an offset or an address
73 uint64_t offset; // Offset of field within structure; only used for nonstatic fields
74 void* address; // Address of field; only used for static fields
75 // ("offset" can not be reused because of apparent solstudio compiler bug
76 // in generation of initializer data)
77} VMStructEntry;
78
79typedef struct {
80 const char* typeName; // Type name (example: "Method")
81 const char* superclassName; // Superclass name, or null if none (example: "oopDesc")
82 int32_t isOopType; // Does this type represent an oop typedef? (i.e., "Method*" or
83 // "Klass*", but NOT "Method")
84 int32_t isIntegerType; // Does this type represent an integer type (of arbitrary size)?
85 int32_t isUnsigned; // If so, is it unsigned?
86 uint64_t size; // Size, in bytes, of the type
87} VMTypeEntry;
88
89typedef struct {
90 const char* name; // Name of constant (example: "_thread_in_native")
91 int32_t value; // Value of constant
92} VMIntConstantEntry;
93
94typedef struct {
95 const char* name; // Name of constant (example: "_thread_in_native")
96 uint64_t value; // Value of constant
97} VMLongConstantEntry;
98
99typedef struct {
100 const char* name; // Name of address (example: "SharedRuntime::register_finalizer")
101 void* value; // Value of address
102} VMAddressEntry;
103
104// This class is a friend of most classes, to be able to access
105// private fields
106class VMStructs {
107public:
108 // The last entry is identified over in the serviceability agent by
109 // the fact that it has a NULL fieldName
110 static VMStructEntry localHotSpotVMStructs[];
111 // The function to get localHotSpotVMStructs length
112 static size_t localHotSpotVMStructsLength();
113
114 // The last entry is identified over in the serviceability agent by
115 // the fact that it has a NULL typeName
116 static VMTypeEntry localHotSpotVMTypes[];
117 // The function to get localHotSpotVMTypes length
118 static size_t localHotSpotVMTypesLength();
119
120 // Table of integer 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 VMIntConstantEntry localHotSpotVMIntConstants[];
124 // The function to get localHotSpotVMIntConstants length
125 static size_t localHotSpotVMIntConstantsLength();
126
127 // Table of long constants required by the serviceability agent.
128 // The last entry is identified over in the serviceability agent by
129 // the fact that it has a NULL typeName
130 static VMLongConstantEntry localHotSpotVMLongConstants[];
131 // The function to get localHotSpotVMIntConstants length
132 static size_t localHotSpotVMLongConstantsLength();
133
134 /**
135 * Table of addresses.
136 */
137 static VMAddressEntry localHotSpotVMAddresses[];
138
139 // This is used to run any checking code necessary for validation of
140 // the data structure (debug build only)
141 static void init();
142
143#ifndef PRODUCT
144 // Execute unit tests
145 static void test();
146#endif
147
148private:
149 // Look up a type in localHotSpotVMTypes using strcmp() (debug build only).
150 // Returns 1 if found, 0 if not.
151 // debug_only(static int findType(const char* typeName);)
152 static int findType(const char* typeName);
153};
154
155// This utility macro quotes the passed string
156#define QUOTE(x) #x
157
158//--------------------------------------------------------------------------------
159// VMStructEntry macros
160//
161
162// This macro generates a VMStructEntry line for a nonstatic field
163#define GENERATE_NONSTATIC_VM_STRUCT_ENTRY(typeName, fieldName, type) \
164 { QUOTE(typeName), QUOTE(fieldName), QUOTE(type), 0, offset_of(typeName, fieldName), NULL },
165
166// This macro generates a VMStructEntry line for a static field
167#define GENERATE_STATIC_VM_STRUCT_ENTRY(typeName, fieldName, type) \
168 { QUOTE(typeName), QUOTE(fieldName), QUOTE(type), 1, 0, &typeName::fieldName },
169
170// This macro generates a VMStructEntry line for a static pointer volatile field,
171// e.g.: "static ObjectMonitor * volatile gBlockList;"
172#define GENERATE_STATIC_PTR_VOLATILE_VM_STRUCT_ENTRY(typeName, fieldName, type) \
173 { QUOTE(typeName), QUOTE(fieldName), QUOTE(type), 1, 0, (void *)&typeName::fieldName },
174
175// This macro generates a VMStructEntry line for an unchecked
176// nonstatic field, in which the size of the type is also specified.
177// The type string is given as NULL, indicating an "opaque" type.
178#define GENERATE_UNCHECKED_NONSTATIC_VM_STRUCT_ENTRY(typeName, fieldName, size) \
179 { QUOTE(typeName), QUOTE(fieldName), NULL, 0, offset_of(typeName, fieldName), NULL },
180
181// This macro generates a VMStructEntry line for an unchecked
182// static field, in which the size of the type is also specified.
183// The type string is given as NULL, indicating an "opaque" type.
184#define GENERATE_UNCHECKED_STATIC_VM_STRUCT_ENTRY(typeName, fieldName, size) \
185 { QUOTE(typeName), QUOTE(fieldName), NULL, 1, 0, (void*) &typeName::fieldName },
186
187// This macro generates the sentinel value indicating the end of the list
188#define GENERATE_VM_STRUCT_LAST_ENTRY() \
189 { NULL, NULL, NULL, 0, 0, NULL }
190
191// This macro checks the type of a VMStructEntry by comparing pointer types
192#define CHECK_NONSTATIC_VM_STRUCT_ENTRY(typeName, fieldName, type) \
193 {typeName *dummyObj = NULL; type* dummy = &dummyObj->fieldName; \
194 assert(offset_of(typeName, fieldName) < sizeof(typeName), "Illegal nonstatic struct entry, field offset too large"); }
195
196// This macro checks the type of a volatile VMStructEntry by comparing pointer types
197#define CHECK_VOLATILE_NONSTATIC_VM_STRUCT_ENTRY(typeName, fieldName, type) \
198 {typedef type dummyvtype; typeName *dummyObj = NULL; volatile dummyvtype* dummy = &dummyObj->fieldName; }
199
200// This macro checks the type of a static VMStructEntry by comparing pointer types
201#define CHECK_STATIC_VM_STRUCT_ENTRY(typeName, fieldName, type) \
202 {type* dummy = &typeName::fieldName; }
203
204// This macro checks the type of a static pointer volatile VMStructEntry by comparing pointer types,
205// e.g.: "static ObjectMonitor * volatile gBlockList;"
206#define CHECK_STATIC_PTR_VOLATILE_VM_STRUCT_ENTRY(typeName, fieldName, type) \
207 {type volatile * dummy = &typeName::fieldName; }
208
209// This macro ensures the type of a field and its containing type are
210// present in the type table. The assertion string is shorter than
211// preferable because (incredibly) of a bug in Solstice NFS client
212// which seems to prevent very long lines from compiling. This assertion
213// means that an entry in VMStructs::localHotSpotVMStructs[] was not
214// found in VMStructs::localHotSpotVMTypes[].
215#define ENSURE_FIELD_TYPE_PRESENT(typeName, fieldName, type) \
216 { assert(findType(QUOTE(typeName)) != 0, "type \"" QUOTE(typeName) "\" not found in type table"); \
217 assert(findType(QUOTE(type)) != 0, "type \"" QUOTE(type) "\" not found in type table"); }
218
219// This is a no-op macro for unchecked fields
220#define CHECK_NO_OP(a, b, c)
221
222
223//--------------------------------------------------------------------------------
224// VMTypeEntry macros
225//
226
227#define GENERATE_VM_TYPE_ENTRY(type, superclass) \
228 { QUOTE(type), QUOTE(superclass), 0, 0, 0, sizeof(type) },
229
230#define GENERATE_TOPLEVEL_VM_TYPE_ENTRY(type) \
231 { QUOTE(type), NULL, 0, 0, 0, sizeof(type) },
232
233#define GENERATE_OOP_VM_TYPE_ENTRY(type) \
234 { QUOTE(type), NULL, 1, 0, 0, sizeof(type) },
235
236#define GENERATE_INTEGER_VM_TYPE_ENTRY(type) \
237 { QUOTE(type), NULL, 0, 1, 0, sizeof(type) },
238
239#define GENERATE_UNSIGNED_INTEGER_VM_TYPE_ENTRY(type) \
240 { QUOTE(type), NULL, 0, 1, 1, sizeof(type) },
241
242#define GENERATE_VM_TYPE_LAST_ENTRY() \
243 { NULL, NULL, 0, 0, 0, 0 }
244
245#define CHECK_VM_TYPE_ENTRY(type, superclass) \
246 { type* dummyObj = NULL; superclass* dummySuperObj = dummyObj; }
247
248#define CHECK_VM_TYPE_NO_OP(a)
249#define CHECK_SINGLE_ARG_VM_TYPE_NO_OP(a)
250
251
252//--------------------------------------------------------------------------------
253// VMIntConstantEntry macros
254//
255
256#define GENERATE_VM_INT_CONSTANT_ENTRY(name) \
257 { QUOTE(name), (int32_t) name },
258
259#define GENERATE_VM_INT_CONSTANT_WITH_VALUE_ENTRY(name, value) \
260 { (name), (int32_t)(value) },
261
262#define GENERATE_PREPROCESSOR_VM_INT_CONSTANT_ENTRY(name, value) \
263 { name, (int32_t) value },
264
265// This macro generates the sentinel value indicating the end of the list
266#define GENERATE_VM_INT_CONSTANT_LAST_ENTRY() \
267 { NULL, 0 }
268
269
270//--------------------------------------------------------------------------------
271// VMLongConstantEntry macros
272//
273
274#define GENERATE_VM_LONG_CONSTANT_ENTRY(name) \
275 { QUOTE(name), name },
276
277#define GENERATE_PREPROCESSOR_VM_LONG_CONSTANT_ENTRY(name, value) \
278 { name, value },
279
280// This macro generates the sentinel value indicating the end of the list
281#define GENERATE_VM_LONG_CONSTANT_LAST_ENTRY() \
282 { NULL, 0 }
283
284
285//--------------------------------------------------------------------------------
286// VMAddressEntry macros
287//
288
289#define GENERATE_VM_ADDRESS_ENTRY(name) \
290 { QUOTE(name), (void*) (name) },
291
292#define GENERATE_PREPROCESSOR_VM_ADDRESS_ENTRY(name, value) \
293 { name, (void*) (value) },
294
295#define GENERATE_VM_FUNCTION_ENTRY(name) \
296 { QUOTE(name), CAST_FROM_FN_PTR(void*, &(name)) },
297
298// This macro generates the sentinel value indicating the end of the list
299#define GENERATE_VM_ADDRESS_LAST_ENTRY() \
300 { NULL, NULL }
301
302#endif // SHARE_RUNTIME_VMSTRUCTS_HPP
303