1 /*
   2  * Copyright (c) 1998, 2016, 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_CODEBLOB_HPP
  26 #define SHARE_VM_CODE_CODEBLOB_HPP
  27 
  28 #include "asm/codeBuffer.hpp"
  29 #include "compiler/oopMap.hpp"
  30 #include "runtime/frame.hpp"
  31 #include "runtime/handles.hpp"
  32 
  33 // CodeBlob Types
  34 // Used in the CodeCache to assign CodeBlobs to different CodeHeaps
  35 struct CodeBlobType {
  36   enum {
  37     MethodNonProfiled   = 0,    // Execution level 1 and 4 (non-profiled) nmethods (including native nmethods)
  38     MethodProfiled      = 1,    // Execution level 2 and 3 (profiled) nmethods
  39     NonNMethod          = 2,    // Non-nmethods like Buffers, Adapters and Runtime Stubs
  40     All                 = 3,    // All types (No code cache segmentation)
  41     Pregenerated        = 4,    // Special blobs, managed by CodeCacheExtensions
  42     NumTypes            = 5     // Number of CodeBlobTypes
  43   };
  44 };
  45 
  46 // CodeBlob - superclass for all entries in the CodeCache.
  47 //
  48 // Subtypes are:
  49 //   CompiledMethod       : Compiled Java methods (include method that calls to native code)
  50 //     nmethod            : JIT Compiled Java methods
  51 //   RuntimeBlob          : Non-compiled method code; generated glue code
  52 //     RuntimeStub        : Call to VM runtime methods
  53 //     DeoptimizationBlob : Used for deoptimization
  54 //     ExceptionBlob      : Used for stack unrolling
  55 //     SafepointBlob      : Used to handle illegal instruction exceptions
  56 //
  57 //
  58 // Layout:
  59 //   - header
  60 //   - relocation
  61 //   - content space
  62 //     - instruction space
  63 //   - data space
  64 
  65 
  66 class CodeBlobLayout;
  67 
  68 class CodeBlob VALUE_OBJ_CLASS_SPEC {
  69   friend class VMStructs;
  70   friend class JVMCIVMStructs;
  71   friend class CodeCacheDumper;
  72 
  73 protected:
  74   const char* _name;
  75   int        _size;                              // total size of CodeBlob in bytes
  76   int        _header_size;                       // size of header (depends on subclass)
  77   int        _frame_complete_offset;             // instruction offsets in [0.._frame_complete_offset) have
  78                                                  // not finished setting up their frame. Beware of pc's in
  79                                                  // that range. There is a similar range(s) on returns
  80                                                  // which we don't detect.
  81   int        _data_offset;                       // offset to where data region begins
  82   int        _frame_size;                        // size of stack frame
  83 
  84   address    _code_begin;
  85   address    _code_end;
  86   address    _content_begin;                     // address to where content region begins (this includes consts, insts, stubs)
  87                                                  // address    _content_end - not required, for all CodeBlobs _code_end == _content_end for now
  88   address    _data_end;
  89   address    _relocation_begin;
  90   address    _relocation_end;
  91 
  92   ImmutableOopMapSet* _oop_maps;                 // OopMap for this CodeBlob
  93   bool                _caller_must_gc_arguments;
  94   CodeStrings         _strings;
  95 
  96   CodeBlob(const char* name, const CodeBlobLayout& layout, int frame_complete_offset, int frame_size, ImmutableOopMapSet* oop_maps, bool caller_must_gc_arguments);
  97   CodeBlob(const char* name, const CodeBlobLayout& layout, CodeBuffer* cb, int frame_complete_offset, int frame_size, OopMapSet* oop_maps, bool caller_must_gc_arguments);
  98 public:
  99   // Returns the space needed for CodeBlob
 100   static unsigned int allocation_size(CodeBuffer* cb, int header_size);
 101   static unsigned int align_code_offset(int offset);
 102 
 103   // Deletion
 104   virtual void flush();
 105 
 106   // Typing
 107   virtual bool is_buffer_blob() const                 { return false; }
 108   virtual bool is_nmethod() const                     { return false; }
 109   virtual bool is_runtime_stub() const                { return false; }
 110   virtual bool is_deoptimization_stub() const         { return false; }
 111   virtual bool is_uncommon_trap_stub() const          { return false; }
 112   virtual bool is_exception_stub() const              { return false; }
 113   virtual bool is_safepoint_stub() const              { return false; }
 114   virtual bool is_adapter_blob() const                { return false; }
 115   virtual bool is_method_handles_adapter_blob() const { return false; }
 116   virtual bool is_compiled() const                    { return false; }
 117 
 118   virtual bool is_compiled_by_c2() const         { return false; }
 119   virtual bool is_compiled_by_c1() const         { return false; }
 120   virtual bool is_compiled_by_jvmci() const      { return false; }
 121 
 122   // Casting
 123   nmethod* as_nmethod_or_null()                { return is_nmethod() ? (nmethod*) this : NULL; }
 124   nmethod* as_nmethod()                        { assert(is_nmethod(), "must be nmethod"); return (nmethod*) this; }
 125   CompiledMethod* as_compiled_method_or_null() { return is_compiled() ? (CompiledMethod*) this : NULL; }
 126   CompiledMethod* as_compiled_method()         { assert(is_compiled(), "must be compiled"); return (CompiledMethod*) this; }
 127 
 128   // Boundaries
 129   address header_begin() const        { return (address) this; }
 130   relocInfo* relocation_begin() const { return (relocInfo*) _relocation_begin; };
 131   relocInfo* relocation_end() const   { return (relocInfo*) _relocation_end; }
 132   address content_begin() const       { return _content_begin; }
 133   address content_end() const         { return _code_end; } // _code_end == _content_end is true for all types of blobs for now, it is also checked in the constructor
 134   address code_begin() const          { return _code_begin;    }
 135   address code_end() const            { return _code_end; }
 136   address data_end() const            { return _data_end;      }
 137 
 138   // Sizes
 139   int size() const                               { return _size; }
 140   int header_size() const                        { return _header_size; }
 141   int relocation_size() const                    { return (address) relocation_end() - (address) relocation_begin(); }
 142   int content_size() const                       { return           content_end()    -           content_begin();    }
 143   int code_size() const                          { return           code_end()       -           code_begin();       }
 144 
 145   // Containment
 146   bool blob_contains(address addr) const         { return header_begin()       <= addr && addr < data_end();       }
 147   bool code_contains(address addr) const         { return code_begin()         <= addr && addr < code_end();       }
 148   bool contains(address addr) const              { return content_begin()      <= addr && addr < content_end();    }
 149   bool is_frame_complete_at(address addr) const  { return code_contains(addr) && addr >= code_begin() + _frame_complete_offset; }
 150 
 151   // CodeCache support: really only used by the nmethods, but in order to get
 152   // asserts and certain bookkeeping to work in the CodeCache they are defined
 153   // virtual here.
 154   virtual bool is_zombie() const                 { return false; }
 155   virtual bool is_locked_by_vm() const           { return false; }
 156 
 157   virtual bool is_unloaded() const               { return false; }
 158   virtual bool is_not_entrant() const            { return false; }
 159 
 160   // GC support
 161   virtual bool is_alive() const                  = 0;
 162 
 163   // OopMap for frame
 164   ImmutableOopMapSet* oop_maps() const           { return _oop_maps; }
 165   void set_oop_maps(OopMapSet* p);
 166   const ImmutableOopMap* oop_map_for_return_address(address return_address);
 167   virtual void preserve_callee_argument_oops(frame fr, const RegisterMap* reg_map, OopClosure* f) = 0;
 168 
 169   // Frame support
 170   int  frame_size() const                        { return _frame_size; }
 171   void set_frame_size(int size)                  { _frame_size = size; }
 172 
 173   // Returns true, if the next frame is responsible for GC'ing oops passed as arguments
 174   bool caller_must_gc_arguments(JavaThread* thread) const { return _caller_must_gc_arguments; }
 175 
 176   // Naming
 177   const char* name() const                       { return _name; }
 178   void set_name(const char* name)                { _name = name; }
 179 
 180   // Debugging
 181   virtual void verify() = 0;
 182   virtual void print() const                     { print_on(tty); };
 183   virtual void print_on(outputStream* st) const;
 184   virtual void print_value_on(outputStream* st) const;
 185   void print_code();
 186 
 187   // Print the comment associated with offset on stream, if there is one
 188   virtual void print_block_comment(outputStream* stream, address block_begin) const {
 189     intptr_t offset = (intptr_t)(block_begin - code_begin());
 190     _strings.print_block_comment(stream, offset);
 191   }
 192 
 193   // Transfer ownership of comments to this CodeBlob
 194   void set_strings(CodeStrings& strings) {
 195     _strings.assign(strings);
 196   }
 197 
 198   static ByteSize name_field_offset() {
 199     return byte_offset_of(CodeBlob, _name);
 200   }
 201 
 202   static ByteSize oop_maps_field_offset() {
 203     return byte_offset_of(CodeBlob, _oop_maps);
 204   }
 205 };
 206 
 207 class CodeBlobLayout : public StackObj {
 208 private:
 209   int _size;
 210   int _header_size;
 211   int _relocation_size;
 212   int _content_offset;
 213   int _code_offset;
 214   int _data_offset;
 215   address _code_begin;
 216   address _code_end;
 217   address _content_begin;
 218   address _content_end;
 219   address _data_end;
 220   address _relocation_begin;
 221   address _relocation_end;
 222 
 223 public:
 224   CodeBlobLayout(address code_begin, address code_end, address content_begin, address content_end, address data_end, address relocation_begin, address relocation_end) :
 225     _size(0),
 226     _header_size(0),
 227     _relocation_size(0),
 228     _content_offset(0),
 229     _code_offset(0),
 230     _data_offset(0),
 231     _content_begin(content_begin),
 232     _content_end(content_end),
 233     _code_begin(code_begin),
 234     _code_end(code_end),
 235     _data_end(data_end),
 236     _relocation_begin(relocation_begin),
 237     _relocation_end(relocation_end)
 238   {
 239   }
 240 
 241   CodeBlobLayout(const address start, int size, int header_size, int relocation_size, int data_offset) :
 242     _size(size),
 243     _header_size(header_size),
 244     _relocation_size(relocation_size),
 245     _content_offset(CodeBlob::align_code_offset(_header_size + _relocation_size)),
 246     _code_offset(_content_offset),
 247     _data_offset(data_offset)
 248   {
 249     assert(_relocation_size == round_to(_relocation_size, oopSize), "unaligned size");
 250 
 251     _code_begin = (address) start + _code_offset;
 252     _code_end = (address) start + _data_offset;
 253 
 254     _content_begin = (address) start + _content_offset;
 255     _content_end = (address) start + _data_offset;
 256 
 257     _data_end = (address) start + _size;
 258     _relocation_begin = (address) start + _header_size;
 259     _relocation_end = _relocation_begin + _relocation_size;
 260   }
 261 
 262   CodeBlobLayout(const address start, int size, int header_size, const CodeBuffer* cb) :
 263     _size(size),
 264     _header_size(header_size),
 265     _relocation_size(round_to(cb->total_relocation_size(), oopSize)),
 266     _content_offset(CodeBlob::align_code_offset(_header_size + _relocation_size)),
 267     _code_offset(_content_offset + cb->total_offset_of(cb->insts())),
 268     _data_offset(_content_offset + round_to(cb->total_content_size(), oopSize))
 269   {
 270     assert(_relocation_size == round_to(_relocation_size, oopSize), "unaligned size");
 271 
 272     _code_begin = (address) start + _code_offset;
 273     _code_end = (address) start + _data_offset;
 274 
 275     _content_begin = (address) start + _content_offset;
 276     _content_end = (address) start + _data_offset;
 277 
 278     _data_end = (address) start + _size;
 279     _relocation_begin = (address) start + _header_size;
 280     _relocation_end = _relocation_begin + _relocation_size;
 281   }
 282 
 283   int size() const { return _size; }
 284   int header_size() const { return _header_size; }
 285   int relocation_size() const { return _relocation_size; }
 286   int content_offset() const { return _content_offset; }
 287   int code_offset() const { return _code_offset; }
 288   int data_offset() const { return _data_offset; }
 289   address code_begin() const { return _code_begin; }
 290   address code_end() const { return _code_end; }
 291   address data_end() const { return _data_end; }
 292   address relocation_begin() const { return _relocation_begin; }
 293   address relocation_end() const { return _relocation_end; }
 294   address content_begin() const { return _content_begin; }
 295   address content_end() const { return _content_end; }
 296 };
 297 
 298 
 299 class RuntimeBlob : public CodeBlob {
 300   friend class VMStructs;
 301  public:
 302 
 303   // Creation
 304   // a) simple CodeBlob
 305   // frame_complete is the offset from the beginning of the instructions
 306   // to where the frame setup (from stackwalk viewpoint) is complete.
 307   RuntimeBlob(const char* name, int header_size, int size, int frame_complete, int locs_size);
 308 
 309   // b) full CodeBlob
 310   RuntimeBlob(
 311     const char* name,
 312     CodeBuffer* cb,
 313     int         header_size,
 314     int         size,
 315     int         frame_complete,
 316     int         frame_size,
 317     OopMapSet*  oop_maps,
 318     bool        caller_must_gc_arguments = false
 319   );
 320 
 321   // GC support
 322   virtual bool is_alive() const                  = 0;
 323 
 324   void verify();
 325 
 326   // OopMap for frame
 327   virtual void preserve_callee_argument_oops(frame fr, const RegisterMap* reg_map, OopClosure* f)  { ShouldNotReachHere(); }
 328 
 329   // Debugging
 330   void print() const                             { print_on(tty); }
 331   virtual void print_on(outputStream* st) const { CodeBlob::print_on(st); }
 332   virtual void print_value_on(outputStream* st) const { CodeBlob::print_value_on(st); }
 333 
 334   // Deal with Disassembler, VTune, Forte, JvmtiExport, MemoryService.
 335   static void trace_new_stub(RuntimeBlob* blob, const char* name1, const char* name2 = "");
 336 };
 337 
 338 class WhiteBox;
 339 //----------------------------------------------------------------------------------------------------
 340 // BufferBlob: used to hold non-relocatable machine code such as the interpreter, stubroutines, etc.
 341 
 342 class BufferBlob: public RuntimeBlob {
 343   friend class VMStructs;
 344   friend class AdapterBlob;
 345   friend class MethodHandlesAdapterBlob;
 346   friend class WhiteBox;
 347 
 348  private:
 349   // Creation support
 350   BufferBlob(const char* name, int size);
 351   BufferBlob(const char* name, int size, CodeBuffer* cb);
 352 
 353   void* operator new(size_t s, unsigned size) throw();
 354 
 355  public:
 356   // Creation
 357   static BufferBlob* create(const char* name, int buffer_size);
 358   static BufferBlob* create(const char* name, CodeBuffer* cb);
 359 
 360   static void free(BufferBlob* buf);
 361 
 362   // Typing
 363   virtual bool is_buffer_blob() const            { return true; }
 364 
 365   // GC/Verification support
 366   void preserve_callee_argument_oops(frame fr, const RegisterMap* reg_map, OopClosure* f)  { /* nothing to do */ }
 367   bool is_alive() const                          { return true; }
 368 
 369   void verify();
 370   void print_on(outputStream* st) const;
 371   void print_value_on(outputStream* st) const;
 372 };
 373 
 374 
 375 //----------------------------------------------------------------------------------------------------
 376 // AdapterBlob: used to hold C2I/I2C adapters
 377 
 378 class AdapterBlob: public BufferBlob {
 379 private:
 380   AdapterBlob(int size, CodeBuffer* cb);
 381 
 382 public:
 383   // Creation
 384   static AdapterBlob* create(CodeBuffer* cb);
 385 
 386   // Typing
 387   virtual bool is_adapter_blob() const { return true; }
 388 };
 389 
 390 
 391 //----------------------------------------------------------------------------------------------------
 392 // MethodHandlesAdapterBlob: used to hold MethodHandles adapters
 393 
 394 class MethodHandlesAdapterBlob: public BufferBlob {
 395 private:
 396   MethodHandlesAdapterBlob(int size)                 : BufferBlob("MethodHandles adapters", size) {}
 397 
 398 public:
 399   // Creation
 400   static MethodHandlesAdapterBlob* create(int buffer_size);
 401 
 402   // Typing
 403   virtual bool is_method_handles_adapter_blob() const { return true; }
 404 };
 405 
 406 
 407 //----------------------------------------------------------------------------------------------------
 408 // RuntimeStub: describes stubs used by compiled code to call a (static) C++ runtime routine
 409 
 410 class RuntimeStub: public RuntimeBlob {
 411   friend class VMStructs;
 412  private:
 413   // Creation support
 414   RuntimeStub(
 415     const char* name,
 416     CodeBuffer* cb,
 417     int         size,
 418     int         frame_complete,
 419     int         frame_size,
 420     OopMapSet*  oop_maps,
 421     bool        caller_must_gc_arguments
 422   );
 423 
 424   void* operator new(size_t s, unsigned size) throw();
 425 
 426  public:
 427   // Creation
 428   static RuntimeStub* new_runtime_stub(
 429     const char* stub_name,
 430     CodeBuffer* cb,
 431     int         frame_complete,
 432     int         frame_size,
 433     OopMapSet*  oop_maps,
 434     bool        caller_must_gc_arguments
 435   );
 436 
 437   // Typing
 438   bool is_runtime_stub() const                   { return true; }
 439 
 440   address entry_point() const                    { return code_begin(); }
 441 
 442   // GC/Verification support
 443   void preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map, OopClosure* f)  { /* nothing to do */ }
 444   bool is_alive() const                          { return true; }
 445 
 446   void verify();
 447   void print_on(outputStream* st) const;
 448   void print_value_on(outputStream* st) const;
 449 };
 450 
 451 
 452 //----------------------------------------------------------------------------------------------------
 453 // Super-class for all blobs that exist in only one instance. Implements default behaviour.
 454 
 455 class SingletonBlob: public RuntimeBlob {
 456   friend class VMStructs;
 457 
 458  protected:
 459   void* operator new(size_t s, unsigned size) throw();
 460 
 461  public:
 462    SingletonBlob(
 463      const char* name,
 464      CodeBuffer* cb,
 465      int         header_size,
 466      int         size,
 467      int         frame_size,
 468      OopMapSet*  oop_maps
 469    )
 470    : RuntimeBlob(name, cb, header_size, size, CodeOffsets::frame_never_safe, frame_size, oop_maps)
 471   {};
 472 
 473   address entry_point()                          { return code_begin(); }
 474 
 475   bool is_alive() const                          { return true; }
 476 
 477   // GC/Verification support
 478   void preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map, OopClosure* f)  { /* nothing to do */ }
 479   void verify(); // does nothing
 480   void print_on(outputStream* st) const;
 481   void print_value_on(outputStream* st) const;
 482 };
 483 
 484 
 485 //----------------------------------------------------------------------------------------------------
 486 // DeoptimizationBlob
 487 
 488 class DeoptimizationBlob: public SingletonBlob {
 489   friend class VMStructs;
 490   friend class JVMCIVMStructs;
 491  private:
 492   int _unpack_offset;
 493   int _unpack_with_exception;
 494   int _unpack_with_reexecution;
 495 
 496   int _unpack_with_exception_in_tls;
 497 
 498 #if INCLUDE_JVMCI
 499   // Offsets when JVMCI calls uncommon_trap.
 500   int _uncommon_trap_offset;
 501   int _implicit_exception_uncommon_trap_offset;
 502 #endif
 503 
 504   // Creation support
 505   DeoptimizationBlob(
 506     CodeBuffer* cb,
 507     int         size,
 508     OopMapSet*  oop_maps,
 509     int         unpack_offset,
 510     int         unpack_with_exception_offset,
 511     int         unpack_with_reexecution_offset,
 512     int         frame_size
 513   );
 514 
 515  public:
 516   // Creation
 517   static DeoptimizationBlob* create(
 518     CodeBuffer* cb,
 519     OopMapSet*  oop_maps,
 520     int         unpack_offset,
 521     int         unpack_with_exception_offset,
 522     int         unpack_with_reexecution_offset,
 523     int         frame_size
 524   );
 525 
 526   // Typing
 527   bool is_deoptimization_stub() const { return true; }
 528   bool exception_address_is_unpack_entry(address pc) const {
 529     address unpack_pc = unpack();
 530     return (pc == unpack_pc || (pc + frame::pc_return_offset) == unpack_pc);
 531   }
 532 
 533   // GC for args
 534   void preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map, OopClosure* f) { /* Nothing to do */ }
 535 
 536   // Printing
 537   void print_value_on(outputStream* st) const;
 538 
 539   address unpack() const                         { return code_begin() + _unpack_offset;           }
 540   address unpack_with_exception() const          { return code_begin() + _unpack_with_exception;   }
 541   address unpack_with_reexecution() const        { return code_begin() + _unpack_with_reexecution; }
 542 
 543   // Alternate entry point for C1 where the exception and issuing pc
 544   // are in JavaThread::_exception_oop and JavaThread::_exception_pc
 545   // instead of being in registers.  This is needed because C1 doesn't
 546   // model exception paths in a way that keeps these registers free so
 547   // there may be live values in those registers during deopt.
 548   void set_unpack_with_exception_in_tls_offset(int offset) {
 549     _unpack_with_exception_in_tls = offset;
 550     assert(code_contains(code_begin() + _unpack_with_exception_in_tls), "must be PC inside codeblob");
 551   }
 552   address unpack_with_exception_in_tls() const   { return code_begin() + _unpack_with_exception_in_tls; }
 553 
 554 #if INCLUDE_JVMCI
 555   // Offsets when JVMCI calls uncommon_trap.
 556   void set_uncommon_trap_offset(int offset) {
 557     _uncommon_trap_offset = offset;
 558     assert(contains(code_begin() + _uncommon_trap_offset), "must be PC inside codeblob");
 559   }
 560   address uncommon_trap() const                  { return code_begin() + _uncommon_trap_offset; }
 561 
 562   void set_implicit_exception_uncommon_trap_offset(int offset) {
 563     _implicit_exception_uncommon_trap_offset = offset;
 564     assert(contains(code_begin() + _implicit_exception_uncommon_trap_offset), "must be PC inside codeblob");
 565   }
 566   address implicit_exception_uncommon_trap() const { return code_begin() + _implicit_exception_uncommon_trap_offset; }
 567 #endif // INCLUDE_JVMCI
 568 };
 569 
 570 
 571 //----------------------------------------------------------------------------------------------------
 572 // UncommonTrapBlob (currently only used by Compiler 2)
 573 
 574 #ifdef COMPILER2
 575 
 576 class UncommonTrapBlob: public SingletonBlob {
 577   friend class VMStructs;
 578  private:
 579   // Creation support
 580   UncommonTrapBlob(
 581     CodeBuffer* cb,
 582     int         size,
 583     OopMapSet*  oop_maps,
 584     int         frame_size
 585   );
 586 
 587  public:
 588   // Creation
 589   static UncommonTrapBlob* create(
 590     CodeBuffer* cb,
 591     OopMapSet*  oop_maps,
 592     int         frame_size
 593   );
 594 
 595   // GC for args
 596   void preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map, OopClosure* f)  { /* nothing to do */ }
 597 
 598   // Typing
 599   bool is_uncommon_trap_stub() const             { return true; }
 600 };
 601 
 602 
 603 //----------------------------------------------------------------------------------------------------
 604 // ExceptionBlob: used for exception unwinding in compiled code (currently only used by Compiler 2)
 605 
 606 class ExceptionBlob: public SingletonBlob {
 607   friend class VMStructs;
 608  private:
 609   // Creation support
 610   ExceptionBlob(
 611     CodeBuffer* cb,
 612     int         size,
 613     OopMapSet*  oop_maps,
 614     int         frame_size
 615   );
 616 
 617  public:
 618   // Creation
 619   static ExceptionBlob* create(
 620     CodeBuffer* cb,
 621     OopMapSet*  oop_maps,
 622     int         frame_size
 623   );
 624 
 625   // GC for args
 626   void preserve_callee_argument_oops(frame fr, const RegisterMap* reg_map, OopClosure* f)  { /* nothing to do */ }
 627 
 628   // Typing
 629   bool is_exception_stub() const                 { return true; }
 630 };
 631 #endif // COMPILER2
 632 
 633 
 634 //----------------------------------------------------------------------------------------------------
 635 // SafepointBlob: handles illegal_instruction exceptions during a safepoint
 636 
 637 class SafepointBlob: public SingletonBlob {
 638   friend class VMStructs;
 639  private:
 640   // Creation support
 641   SafepointBlob(
 642     CodeBuffer* cb,
 643     int         size,
 644     OopMapSet*  oop_maps,
 645     int         frame_size
 646   );
 647 
 648  public:
 649   // Creation
 650   static SafepointBlob* create(
 651     CodeBuffer* cb,
 652     OopMapSet*  oop_maps,
 653     int         frame_size
 654   );
 655 
 656   // GC for args
 657   void preserve_callee_argument_oops(frame fr, const RegisterMap* reg_map, OopClosure* f)  { /* nothing to do */ }
 658 
 659   // Typing
 660   bool is_safepoint_stub() const                 { return true; }
 661 };
 662 
 663 #endif // SHARE_VM_CODE_CODEBLOB_HPP