1 /*
   2  * Copyright (c) 1998, 2012, 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_CODE_DEBUGINFOREC_HPP
  26 #define SHARE_VM_CODE_DEBUGINFOREC_HPP
  27 
  28 #include "ci/ciClassList.hpp"
  29 #include "ci/ciInstanceKlass.hpp"
  30 #include "ci/ciMethod.hpp"
  31 #include "code/debugInfo.hpp"
  32 #include "code/location.hpp"
  33 #include "code/pcDesc.hpp"
  34 #include "compiler/oopMap.hpp"
  35 #include "oops/oop.hpp"
  36 #include "utilities/growableArray.hpp"
  37 
  38 //** The DebugInformationRecorder collects debugging information
  39 //   for a compiled method.
  40 //   Debugging information is used for:
  41 //   - garbage collecting compiled frames
  42 //   - stack tracing across compiled frames
  43 //   - deoptimizating compiled frames
  44 //
  45 //   The implementation requires the compiler to use the recorder
  46 //   in the following order:
  47 //   1) Describe debug information for safepoints at increasing addresses.
  48 //      a) Add safepoint entry (use add_safepoint or add_non_safepoint)
  49 //      b) Describe scopes for that safepoint
  50 //         - create locals if needed (use create_scope_values)
  51 //         - create expressions if needed (use create_scope_values)
  52 //         - create monitor stack if needed (use create_monitor_values)
  53 //         - describe scope (use describe_scope)
  54 //         "repeat last four steps for all scopes"
  55 //         "outer most scope first and inner most scope last"
  56 //         NB: nodes from create_scope_values and create_locations
  57 //             can be reused for simple sharing.
  58 //         - mark the end of the scopes (end_safepoint or end_non_safepoint)
  59 //   2) Use oop_size, metadata_size, data_size, pcs_size to create the nmethod
  60 //      and finally migrate the debugging information into the nmethod
  61 //      by calling copy_to.
  62 
  63 class DebugToken; // Opaque datatype for stored:
  64                   //  - GrowableArray<ScopeValue*>
  65                   //  - GrowableArray<MonitorValue*>
  66 
  67 // Alias for InvocationEntryBci.
  68 // Both constants are used for a pseudo-BCI which refers
  69 // to the state just _before_ a method is entered.
  70 // SynchronizationEntryBCI is used where the emphasis
  71 // is on the implicit monitorenter of a synchronized method.
  72 const int SynchronizationEntryBCI = InvocationEntryBci;
  73 
  74 class DIR_Chunk; // private class, a nugget of collected information
  75 
  76 class DebugInformationRecorder: public ResourceObj {
  77  public:
  78   // constructor
  79   DebugInformationRecorder(OopRecorder* oop_recorder);
  80 
  81   // adds an oopmap at a specific offset
  82   void add_oopmap(int pc_offset, OopMap* map);
  83 
  84   // adds a jvm mapping at pc-offset, for a safepoint only
  85   void add_safepoint(int pc_offset, OopMap* map);
  86 
  87   // adds a jvm mapping at pc-offset, for a non-safepoint (profile point)
  88   void add_non_safepoint(int pc_offset);
  89 
  90   // Describes debugging information for a scope at the given pc_offset.
  91   // Calls must be in non-decreasing order of pc_offset.
  92   // If there are several calls at a single pc_offset,
  93   // then they occur in the same order as they were performed by the JVM,
  94   // with the most recent (innermost) call being described last.
  95   // For a safepoint, the pc_offset must have been mentioned
  96   // previously by add_safepoint.
  97   // Otherwise, the pc_offset must have been mentioned previously
  98   // by add_non_safepoint, and the locals, expressions, and monitors
  99   // must all be null.
 100   void describe_scope(int         pc_offset,
 101                       ciMethod*   method,
 102                       int         bci,
 103                       bool        reexecute,
 104                       bool        is_method_handle_invoke = false,
 105                       bool        return_oop = false,
 106                       DebugToken* locals      = NULL,
 107                       DebugToken* expressions = NULL,
 108                       DebugToken* monitors    = NULL);
 109 
 110 
 111   void dump_object_pool(GrowableArray<ScopeValue*>* objects);
 112 
 113   // This call must follow every add_safepoint,
 114   // after any intervening describe_scope calls.
 115   void end_safepoint(int pc_offset)      { end_scopes(pc_offset, true); }
 116   void end_non_safepoint(int pc_offset)  { end_scopes(pc_offset, false); }
 117 
 118   // helper fuctions for describe_scope to enable sharing
 119   DebugToken* create_scope_values(GrowableArray<ScopeValue*>* values);
 120   DebugToken* create_monitor_values(GrowableArray<MonitorValue*>* monitors);
 121 
 122   // returns the size of the generated scopeDescs.
 123   int data_size();
 124   int pcs_size();
 125   int oop_size() { return oop_recorder()->oop_size(); }
 126   int metadata_size() { return oop_recorder()->metadata_size(); }
 127 
 128   // copy the generated debugging information to nmethod
 129   void copy_to(nmethod* nm);
 130 
 131   // verifies the debug information
 132   void verify(const nmethod* code);
 133 
 134   static void print_statistics() PRODUCT_RETURN;
 135 
 136   // Method for setting oopmaps to temporarily preserve old handling of oopmaps
 137   OopMapSet *_oopmaps;
 138   void set_oopmaps(OopMapSet *oopmaps) { _oopmaps = oopmaps; }
 139 
 140   OopRecorder* oop_recorder() { return _oop_recorder; }
 141 
 142   int last_pc_offset() { return last_pc()->pc_offset(); }
 143 
 144   bool recording_non_safepoints() { return _recording_non_safepoints; }
 145 
 146  private:
 147   friend class ScopeDesc;
 148   friend class vframeStreamCommon;
 149   friend class DIR_Chunk;
 150 
 151   // True if we are recording non-safepoint scopes.
 152   // This flag is set if DebugNonSafepoints is true, or if
 153   // JVMTI post_compiled_method_load events are enabled.
 154   const bool _recording_non_safepoints;
 155 
 156   DebugInfoWriteStream* _stream;
 157 
 158   DebugInfoWriteStream* stream() const { return _stream; }
 159 
 160   OopRecorder* _oop_recorder;
 161 
 162   // Scopes that have been described so far.
 163   GrowableArray<DIR_Chunk*>* _all_chunks;
 164   GrowableArray<DIR_Chunk*>* _shared_chunks;
 165   DIR_Chunk* _next_chunk;
 166   DIR_Chunk* _next_chunk_limit;
 167 
 168 #ifdef ASSERT
 169   enum { rs_null, rs_safepoint, rs_non_safepoint };
 170   int _recording_state;
 171 #endif
 172 
 173   PcDesc* _pcs;
 174   int     _pcs_size;
 175   int     _pcs_length;
 176   // Note:  Would use GrowableArray<PcDesc>, but structs are not supported.
 177 
 178   // PC of most recent real safepoint before the current one,
 179   // updated after end_scopes.
 180   int _prev_safepoint_pc;
 181 
 182   PcDesc* last_pc() {
 183     guarantee(_pcs_length > 0, "a safepoint must be declared already");
 184     return &_pcs[_pcs_length-1];
 185   }
 186   PcDesc* prev_pc() {
 187     guarantee(_pcs_length > 1, "a safepoint must be declared already");
 188     return &_pcs[_pcs_length-2];
 189   }
 190   void add_new_pc_offset(int pc_offset);
 191   void end_scopes(int pc_offset, bool is_safepoint);
 192 
 193   int  serialize_monitor_values(GrowableArray<MonitorValue*>* monitors);
 194   int  serialize_scope_values(GrowableArray<ScopeValue*>* values);
 195   int  find_sharable_decode_offset(int stream_offset);
 196 
 197 #ifndef PRODUCT
 198   bool recorders_frozen();
 199   void mark_recorders_frozen();
 200 #endif // PRODUCT
 201 
 202  public:
 203   enum { serialized_null = 0 };
 204 };
 205 
 206 #endif // SHARE_VM_CODE_DEBUGINFOREC_HPP