1 /* 2 * Copyright 1998-2005 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, 20 * CA 95054 USA or visit www.sun.com if you need additional information or 21 * have any questions. 22 * 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 DebugToken* locals = NULL, 91 DebugToken* expressions = NULL, 92 DebugToken* monitors = NULL); 93 94 95 void dump_object_pool(GrowableArray<ScopeValue*>* objects); 96 97 // This call must follow every add_safepoint, 98 // after any intervening describe_scope calls. 99 void end_safepoint(int pc_offset) { end_scopes(pc_offset, true); } 100 void end_non_safepoint(int pc_offset) { end_scopes(pc_offset, false); } 101 102 // helper fuctions for describe_scope to enable sharing 103 DebugToken* create_scope_values(GrowableArray<ScopeValue*>* values); 104 DebugToken* create_monitor_values(GrowableArray<MonitorValue*>* monitors); 105 106 // returns the size of the generated scopeDescs. 107 int data_size(); 108 int pcs_size(); 109 int oop_size() { return oop_recorder()->oop_size(); } 110 111 // copy the generated debugging information to nmethod 112 void copy_to(nmethod* nm); 113 114 // verifies the debug information 115 void verify(const nmethod* code); 116 117 static void print_statistics() PRODUCT_RETURN; 118 119 // Method for setting oopmaps to temporarily preserve old handling of oopmaps 120 OopMapSet *_oopmaps; 121 void set_oopmaps(OopMapSet *oopmaps) { _oopmaps = oopmaps; } 122 123 OopRecorder* oop_recorder() { return _oop_recorder; } 124 125 int last_pc_offset() { return last_pc()->pc_offset(); } 126 127 bool recording_non_safepoints() { return _recording_non_safepoints; } 128 129 private: 130 friend class ScopeDesc; 131 friend class vframeStreamCommon; 132 friend class DIR_Chunk; 133 134 // True if we are recording non-safepoint scopes. 135 // This flag is set if DebugNonSafepoints is true, or if 136 // JVMTI post_compiled_method_load events are enabled. 137 const bool _recording_non_safepoints; 138 139 DebugInfoWriteStream* _stream; 140 141 DebugInfoWriteStream* stream() const { return _stream; } 142 143 OopRecorder* _oop_recorder; 144 145 // Scopes that have been described so far. 146 GrowableArray<DIR_Chunk*>* _all_chunks; 147 GrowableArray<DIR_Chunk*>* _shared_chunks; 148 DIR_Chunk* _next_chunk; 149 DIR_Chunk* _next_chunk_limit; 150 151 #ifdef ASSERT 152 enum { rs_null, rs_safepoint, rs_non_safepoint }; 153 int _recording_state; 154 #endif 155 156 PcDesc* _pcs; 157 int _pcs_size; 158 int _pcs_length; 159 // Note: Would use GrowableArray<PcDesc>, but structs are not supported. 160 161 // PC of most recent real safepoint before the current one, 162 // updated after end_scopes. 163 int _prev_safepoint_pc; 164 165 PcDesc* last_pc() { 166 guarantee(_pcs_length > 0, "a safepoint must be declared already"); 167 return &_pcs[_pcs_length-1]; 168 } 169 PcDesc* prev_pc() { 170 guarantee(_pcs_length > 1, "a safepoint must be declared already"); 171 return &_pcs[_pcs_length-2]; 172 } 173 void add_new_pc_offset(int pc_offset); 174 void end_scopes(int pc_offset, bool is_safepoint); 175 176 int serialize_monitor_values(GrowableArray<MonitorValue*>* monitors); 177 int serialize_scope_values(GrowableArray<ScopeValue*>* values); 178 int find_sharable_decode_offset(int stream_offset); 179 180 public: 181 enum { serialized_null = 0 }; 182 };