1 /*
2 * Copyright (c) 1998, 2009, 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 //** The DebugInformationRecorder collects debugging information
26 // for a compiled method.
27 // Debugging information is used for:
28 // - garbage collecting compiled frames
29 // - stack tracing across compiled frames
30 // - deoptimizating compiled frames
31 //
32 // The implementation requires the compiler to use the recorder
33 // in the following order:
34 // 1) Describe debug information for safepoints at increasing addresses.
35 // a) Add safepoint entry (use add_safepoint or add_non_safepoint)
36 // b) Describe scopes for that safepoint
37 // - create locals if needed (use create_scope_values)
38 // - create expressions if needed (use create_scope_values)
39 // - create monitor stack if needed (use create_monitor_values)
40 // - describe scope (use describe_scope)
41 // "repeat last four steps for all scopes"
42 // "outer most scope first and inner most scope last"
43 // NB: nodes from create_scope_values and create_locations
44 // can be reused for simple sharing.
45 // - mark the end of the scopes (end_safepoint or end_non_safepoint)
46 // 2) Use oop_size, data_size, pcs_size to create the nmethod and
47 // finally migrate the debugging information into the nmethod
48 // by calling copy_to.
49
50 class DebugToken; // Opaque datatype for stored:
51 // - GrowableArray<ScopeValue*>
52 // - GrowableArray<MonitorValue*>
53
54 // Alias for InvocationEntryBci.
55 // Both constants are used for a pseudo-BCI which refers
56 // to the state just _before_ a method is entered.
57 // SynchronizationEntryBCI is used where the emphasis
58 // is on the implicit monitorenter of a synchronized method.
59 const int SynchronizationEntryBCI = InvocationEntryBci;
60
61 class DIR_Chunk; // private class, a nugget of collected information
62
63 class DebugInformationRecorder: public ResourceObj {
64 public:
65 // constructor
66 DebugInformationRecorder(OopRecorder* oop_recorder);
67
68 // adds an oopmap at a specific offset
69 void add_oopmap(int pc_offset, OopMap* map);
70
71 // adds a jvm mapping at pc-offset, for a safepoint only
72 void add_safepoint(int pc_offset, OopMap* map);
73
74 // adds a jvm mapping at pc-offset, for a non-safepoint (profile point)
75 void add_non_safepoint(int pc_offset);
76
77 // Describes debugging information for a scope at the given pc_offset.
78 // Calls must be in non-decreasing order of pc_offset.
79 // If there are several calls at a single pc_offset,
80 // then they occur in the same order as they were performed by the JVM,
81 // with the most recent (innermost) call being described last.
82 // For a safepoint, the pc_offset must have been mentioned
83 // previously by add_safepoint.
84 // Otherwise, the pc_offset must have been mentioned previously
85 // by add_non_safepoint, and the locals, expressions, and monitors
86 // must all be null.
87 void describe_scope(int pc_offset,
88 ciMethod* method,
89 int bci,
90 bool reexecute,
91 bool is_method_handle_invoke = false,
92 bool return_oop = false,
93 DebugToken* locals = NULL,
94 DebugToken* expressions = NULL,
95 DebugToken* monitors = NULL);
96
97
98 void dump_object_pool(GrowableArray<ScopeValue*>* objects);
99
100 // This call must follow every add_safepoint,
101 // after any intervening describe_scope calls.
102 void end_safepoint(int pc_offset) { end_scopes(pc_offset, true); }
103 void end_non_safepoint(int pc_offset) { end_scopes(pc_offset, false); }
104
105 // helper fuctions for describe_scope to enable sharing
106 DebugToken* create_scope_values(GrowableArray<ScopeValue*>* values);
107 DebugToken* create_monitor_values(GrowableArray<MonitorValue*>* monitors);
108
109 // returns the size of the generated scopeDescs.
110 int data_size();
111 int pcs_size();
112 int oop_size() { return oop_recorder()->oop_size(); }
113
114 // copy the generated debugging information to nmethod
115 void copy_to(nmethod* nm);
116
117 // verifies the debug information
118 void verify(const nmethod* code);
119
120 static void print_statistics() PRODUCT_RETURN;
121
122 // Method for setting oopmaps to temporarily preserve old handling of oopmaps
123 OopMapSet *_oopmaps;
124 void set_oopmaps(OopMapSet *oopmaps) { _oopmaps = oopmaps; }
125
126 OopRecorder* oop_recorder() { return _oop_recorder; }
127
128 int last_pc_offset() { return last_pc()->pc_offset(); }
129
130 bool recording_non_safepoints() { return _recording_non_safepoints; }
131
132 private:
133 friend class ScopeDesc;
134 friend class vframeStreamCommon;
135 friend class DIR_Chunk;
136
137 // True if we are recording non-safepoint scopes.
138 // This flag is set if DebugNonSafepoints is true, or if
139 // JVMTI post_compiled_method_load events are enabled.
140 const bool _recording_non_safepoints;
141
142 DebugInfoWriteStream* _stream;
143
144 DebugInfoWriteStream* stream() const { return _stream; }
145
146 OopRecorder* _oop_recorder;
147
148 // Scopes that have been described so far.
149 GrowableArray<DIR_Chunk*>* _all_chunks;
150 GrowableArray<DIR_Chunk*>* _shared_chunks;
151 DIR_Chunk* _next_chunk;
152 DIR_Chunk* _next_chunk_limit;
153
154 #ifdef ASSERT
155 enum { rs_null, rs_safepoint, rs_non_safepoint };
156 int _recording_state;
157 #endif
158
159 PcDesc* _pcs;
160 int _pcs_size;
161 int _pcs_length;
162 // Note: Would use GrowableArray<PcDesc>, but structs are not supported.
163
164 // PC of most recent real safepoint before the current one,
165 // updated after end_scopes.
166 int _prev_safepoint_pc;
167
168 PcDesc* last_pc() {
169 guarantee(_pcs_length > 0, "a safepoint must be declared already");
170 return &_pcs[_pcs_length-1];
171 }
172 PcDesc* prev_pc() {
173 guarantee(_pcs_length > 1, "a safepoint must be declared already");
174 return &_pcs[_pcs_length-2];
175 }
176 void add_new_pc_offset(int pc_offset);
177 void end_scopes(int pc_offset, bool is_safepoint);
178
179 int serialize_monitor_values(GrowableArray<MonitorValue*>* monitors);
180 int serialize_scope_values(GrowableArray<ScopeValue*>* values);
181 int find_sharable_decode_offset(int stream_offset);
182
183 public:
184 enum { serialized_null = 0 };
185 };