1 /*
  2  * Copyright (c) 1998, 2018, 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/compilerDefinitions.hpp"
 30 #include "compiler/oopMap.hpp"
 31 #include "runtime/frame.hpp"
 32 #include "runtime/handles.hpp"
 33 #include "utilities/align.hpp"
 34 #include "utilities/macros.hpp"
 35 
 36 // CodeBlob Types
 37 // Used in the CodeCache to assign CodeBlobs to different CodeHeaps
 38 struct CodeBlobType {
 39   enum {
 40     MethodNonProfiled   = 0,    // Execution level 1 and 4 (non-profiled) nmethods (including native nmethods)
 41     MethodProfiled      = 1,    // Execution level 2 and 3 (profiled) nmethods
 42     NonNMethod          = 2,    // Non-nmethods like Buffers, Adapters and Runtime Stubs
 43     All                 = 3,    // All types (No code cache segmentation)
 44     AOT                 = 4,    // AOT methods
 45     NumTypes            = 5     // Number of CodeBlobTypes
 46   };
 47 };
 48 
 49 // CodeBlob - superclass for all entries in the CodeCache.
 50 //
 51 // Subtypes are:
 52 //  CompiledMethod       : Compiled Java methods (include method that calls to native code)
 53 //   nmethod             : JIT Compiled Java methods
 54 //   AOTCompiledMethod   : AOT Compiled Java methods - Not in the CodeCache!
 55 //                         AOTCompiledMethod objects are allocated in the C-Heap, the code they
 56 //                         point to is allocated in the AOTCodeHeap which is in the C-Heap as
 57 //                         well (i.e. it's the memory where the shared library was loaded to)
 58 //  RuntimeBlob          : Non-compiled method code; generated glue code
 59 //   BufferBlob          : Used for non-relocatable code such as interpreter, stubroutines, etc.
 60 //    AdapterBlob        : Used to hold C2I/I2C adapters
 61 //    VtableBlob         : Used for holding vtable chunks
 62 //    MethodHandlesAdapterBlob : Used to hold MethodHandles adapters
 63 //   RuntimeStub         : Call to VM runtime methods
 64 //   SingletonBlob       : Super-class for all blobs that exist in only one instance
 65 //    DeoptimizationBlob : Used for deoptimization
 66 //    ExceptionBlob      : Used for stack unrolling
 67 //    SafepointBlob      : Used to handle illegal instruction exceptions
 68 //    UncommonTrapBlob   : Used to handle uncommon traps
 69 //
 70 //
 71 // Layout (all except AOTCompiledMethod) : continuous in the CodeCache
 72 //   - header
 73 //   - relocation
 74 //   - content space
 75 //     - instruction space
 76 //   - data space
 77 //
 78 // Layout (AOTCompiledMethod) : in the C-Heap
 79 //   - header -\
 80 //     ...     |
 81 //   - code  <-/
 82 
 83 
 84 class CodeBlobLayout;
 85 
 86 class CodeBlob {
 87   friend class VMStructs;
 88   friend class JVMCIVMStructs;
 89   friend class CodeCacheDumper;
 90 
 91 protected:
 92 
 93   const CompilerType _type;                      // CompilerType
 94   int        _size;                              // total size of CodeBlob in bytes
 95   int        _header_size;                       // size of header (depends on subclass)
 96   int        _frame_complete_offset;             // instruction offsets in [0.._frame_complete_offset) have
 97                                                  // not finished setting up their frame. Beware of pc's in
 98                                                  // that range. There is a similar range(s) on returns
 99                                                  // which we don't detect.
100   int        _data_offset;                       // offset to where data region begins
101   int        _frame_size;                        // size of stack frame
102 
103   address    _code_begin;
104   address    _code_end;
105   address    _content_begin;                     // address to where content region begins (this includes consts, insts, stubs)
106                                                  // address    _content_end - not required, for all CodeBlobs _code_end == _content_end for now
107   address    _data_end;
108   address    _relocation_begin;
109   address    _relocation_end;
110 
111   ImmutableOopMapSet* _oop_maps;                 // OopMap for this CodeBlob
112   bool                _caller_must_gc_arguments;
113   CodeStrings         _strings;
114   const char*         _name;
115   S390_ONLY(int       _ctable_offset;)
116 
117   CodeBlob(const char* name, CompilerType type, const CodeBlobLayout& layout, int frame_complete_offset, int frame_size, ImmutableOopMapSet* oop_maps, bool caller_must_gc_arguments);
118   CodeBlob(const char* name, CompilerType type, const CodeBlobLayout& layout, CodeBuffer* cb, int frame_complete_offset, int frame_size, OopMapSet* oop_maps, bool caller_must_gc_arguments);
119 
120 public:
121   // Only used by unit test.
122   CodeBlob()
123     : _type(compiler_none) {}
124 
125   // Returns the space needed for CodeBlob
126   static unsigned int allocation_size(CodeBuffer* cb, int header_size);
127   static unsigned int align_code_offset(int offset);
128 
129   // Deletion
130   virtual void flush();
131 
132   // Typing
133   virtual bool is_buffer_blob() const                 { return false; }
134   virtual bool is_nmethod() const                     { return false; }
135   virtual bool is_runtime_stub() const                { return false; }
136   virtual bool is_deoptimization_stub() const         { return false; }
137   virtual bool is_uncommon_trap_stub() const          { return false; }
138   virtual bool is_exception_stub() const              { return false; }
139   virtual bool is_safepoint_stub() const              { return false; }
140   virtual bool is_adapter_blob() const                { return false; }
141   virtual bool is_vtable_blob() const                 { return false; }
142   virtual bool is_method_handles_adapter_blob() const { return false; }
143   virtual bool is_aot() const                         { return false; }
144   virtual bool is_compiled() const                    { return false; }
145 
146   inline bool is_compiled_by_c1() const    { return _type == compiler_c1; };
147   inline bool is_compiled_by_c2() const    { return _type == compiler_c2; };
148   inline bool is_compiled_by_jvmci() const { return _type == compiler_jvmci; };
149   const char* compiler_name() const;
150 
151   // Casting
152   nmethod* as_nmethod_or_null()                { return is_nmethod() ? (nmethod*) this : NULL; }
153   nmethod* as_nmethod()                        { assert(is_nmethod(), "must be nmethod"); return (nmethod*) this; }
154   CompiledMethod* as_compiled_method_or_null() { return is_compiled() ? (CompiledMethod*) this : NULL; }
155   CompiledMethod* as_compiled_method()         { assert(is_compiled(), "must be compiled"); return (CompiledMethod*) this; }
156   CodeBlob* as_codeblob_or_null() const        { return (CodeBlob*) this; }
157 
158   // Boundaries
159   address header_begin() const        { return (address) this; }
160   relocInfo* relocation_begin() const { return (relocInfo*) _relocation_begin; };
161   relocInfo* relocation_end() const   { return (relocInfo*) _relocation_end; }
162   address content_begin() const       { return _content_begin; }
163   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
164   address code_begin() const          { return _code_begin;    }
165   address code_end() const            { return _code_end; }
166   address data_end() const            { return _data_end;      }
167 
168   // This field holds the beginning of the const section in the old code buffer.
169   // It is needed to fix relocations of pc-relative loads when resizing the
170   // the constant pool or moving it.
171   S390_ONLY(address ctable_begin() const { return header_begin() + _ctable_offset; })
172   void set_ctable_begin(address ctable) { S390_ONLY(_ctable_offset = ctable - header_begin();) }
173 
174   // Sizes
175   int size() const                               { return _size; }
176   int header_size() const                        { return _header_size; }
177   int relocation_size() const                    { return (address) relocation_end() - (address) relocation_begin(); }
178   int content_size() const                       { return           content_end()    -           content_begin();    }
179   int code_size() const                          { return           code_end()       -           code_begin();       }
180   // Only used from CodeCache::free_unused_tail() after the Interpreter blob was trimmed
181   void adjust_size(size_t used) {
182     _size = (int)used;
183     _data_offset = (int)used;
184     _code_end = (address)this + used;
185     _data_end = (address)this + used;
186   }
187 
188   // Containment
189   bool blob_contains(address addr) const         { return header_begin()       <= addr && addr < data_end();       }
190   bool code_contains(address addr) const         { return code_begin()         <= addr && addr < code_end();       }
191   bool contains(address addr) const              { return content_begin()      <= addr && addr < content_end();    }
192   bool is_frame_complete_at(address addr) const  { return _frame_complete_offset != CodeOffsets::frame_never_safe &&
193                                                           code_contains(addr) && addr >= code_begin() + _frame_complete_offset; }
194   int frame_complete_offset() const              { return _frame_complete_offset; }
195 
196   // CodeCache support: really only used by the nmethods, but in order to get
197   // asserts and certain bookkeeping to work in the CodeCache they are defined
198   // virtual here.
199   virtual bool is_zombie() const                 { return false; }
200   virtual bool is_locked_by_vm() const           { return false; }
201 
202   virtual bool is_unloaded() const               { return false; }
203   virtual bool is_not_entrant() const            { return false; }
204 
205   // GC support
206   virtual bool is_alive() const                  = 0;
207 
208   // OopMap for frame
209   ImmutableOopMapSet* oop_maps() const           { return _oop_maps; }
210   void set_oop_maps(OopMapSet* p);
211   const ImmutableOopMap* oop_map_for_return_address(address return_address);
212   virtual void preserve_callee_argument_oops(frame fr, const RegisterMap* reg_map, OopClosure* f) = 0;
213 
214   // Frame support
215   int  frame_size() const                        { return _frame_size; }
216   void set_frame_size(int size)                  { _frame_size = size; }
217 
218   // Returns true, if the next frame is responsible for GC'ing oops passed as arguments
219   bool caller_must_gc_arguments(JavaThread* thread) const { return _caller_must_gc_arguments; }
220 
221   // Naming
222   const char* name() const                       { return _name; }
223   void set_name(const char* name)                { _name = name; }
224 
225   // Debugging
226   virtual void verify() = 0;
227   virtual void print() const                     { print_on(tty); };
228   virtual void print_on(outputStream* st) const;
229   virtual void print_value_on(outputStream* st) const;
230   void dump_for_addr(address addr, outputStream* st, bool verbose) const;
231   void print_code();
232 
233   // Print the comment associated with offset on stream, if there is one
234   virtual void print_block_comment(outputStream* stream, address block_begin) const {
235     intptr_t offset = (intptr_t)(block_begin - code_begin());
236     _strings.print_block_comment(stream, offset);
237   }
238 
239   // Transfer ownership of comments to this CodeBlob
240   void set_strings(CodeStrings& strings) {
241     assert(!is_aot(), "invalid on aot");
242     _strings.assign(strings);
243   }
244 
245   static ByteSize name_field_offset() {
246     return byte_offset_of(CodeBlob, _name);
247   }
248 
249   static ByteSize oop_maps_field_offset() {
250     return byte_offset_of(CodeBlob, _oop_maps);
251   }
252 };
253 
254 class CodeBlobLayout : public StackObj {
255 private:
256   int _size;
257   int _header_size;
258   int _relocation_size;
259   int _content_offset;
260   int _code_offset;
261   int _data_offset;
262   address _code_begin;
263   address _code_end;
264   address _content_begin;
265   address _content_end;
266   address _data_end;
267   address _relocation_begin;
268   address _relocation_end;
269 
270 public:
271   CodeBlobLayout(address code_begin, address code_end, address content_begin, address content_end, address data_end, address relocation_begin, address relocation_end) :
272     _size(0),
273     _header_size(0),
274     _relocation_size(0),
275     _content_offset(0),
276     _code_offset(0),
277     _data_offset(0),
278     _code_begin(code_begin),
279     _code_end(code_end),
280     _content_begin(content_begin),
281     _content_end(content_end),
282     _data_end(data_end),
283     _relocation_begin(relocation_begin),
284     _relocation_end(relocation_end)
285   {
286   }
287 
288   CodeBlobLayout(const address start, int size, int header_size, int relocation_size, int data_offset) :
289     _size(size),
290     _header_size(header_size),
291     _relocation_size(relocation_size),
292     _content_offset(CodeBlob::align_code_offset(_header_size + _relocation_size)),
293     _code_offset(_content_offset),
294     _data_offset(data_offset)
295   {
296     assert(is_aligned(_relocation_size, oopSize), "unaligned size");
297 
298     _code_begin = (address) start + _code_offset;
299     _code_end = (address) start + _data_offset;
300 
301     _content_begin = (address) start + _content_offset;
302     _content_end = (address) start + _data_offset;
303 
304     _data_end = (address) start + _size;
305     _relocation_begin = (address) start + _header_size;
306     _relocation_end = _relocation_begin + _relocation_size;
307   }
308 
309   CodeBlobLayout(const address start, int size, int header_size, const CodeBuffer* cb) :
310     _size(size),
311     _header_size(header_size),
312     _relocation_size(align_up(cb->total_relocation_size(), oopSize)),
313     _content_offset(CodeBlob::align_code_offset(_header_size + _relocation_size)),
314     _code_offset(_content_offset + cb->total_offset_of(cb->insts())),
315     _data_offset(_content_offset + align_up(cb->total_content_size(), oopSize))
316   {
317     assert(is_aligned(_relocation_size, oopSize), "unaligned size");
318 
319     _code_begin = (address) start + _code_offset;
320     _code_end = (address) start + _data_offset;
321 
322     _content_begin = (address) start + _content_offset;
323     _content_end = (address) start + _data_offset;
324 
325     _data_end = (address) start + _size;
326     _relocation_begin = (address) start + _header_size;
327     _relocation_end = _relocation_begin + _relocation_size;
328   }
329 
330   int size() const { return _size; }
331   int header_size() const { return _header_size; }
332   int relocation_size() const { return _relocation_size; }
333   int content_offset() const { return _content_offset; }
334   int code_offset() const { return _code_offset; }
335   int data_offset() const { return _data_offset; }
336   address code_begin() const { return _code_begin; }
337   address code_end() const { return _code_end; }
338   address data_end() const { return _data_end; }
339   address relocation_begin() const { return _relocation_begin; }
340   address relocation_end() const { return _relocation_end; }
341   address content_begin() const { return _content_begin; }
342   address content_end() const { return _content_end; }
343 };
344 
345 
346 class RuntimeBlob : public CodeBlob {
347   friend class VMStructs;
348  public:
349 
350   // Creation
351   // a) simple CodeBlob
352   // frame_complete is the offset from the beginning of the instructions
353   // to where the frame setup (from stackwalk viewpoint) is complete.
354   RuntimeBlob(const char* name, int header_size, int size, int frame_complete, int locs_size);
355 
356   // b) full CodeBlob
357   RuntimeBlob(
358     const char* name,
359     CodeBuffer* cb,
360     int         header_size,
361     int         size,
362     int         frame_complete,
363     int         frame_size,
364     OopMapSet*  oop_maps,
365     bool        caller_must_gc_arguments = false
366   );
367 
368   // GC support
369   virtual bool is_alive() const                  = 0;
370 
371   void verify();
372 
373   // OopMap for frame
374   virtual void preserve_callee_argument_oops(frame fr, const RegisterMap* reg_map, OopClosure* f)  { ShouldNotReachHere(); }
375 
376   // Debugging
377   void print() const                             { print_on(tty); }
378   virtual void print_on(outputStream* st) const { CodeBlob::print_on(st); }
379   virtual void print_value_on(outputStream* st) const { CodeBlob::print_value_on(st); }
380 
381   // Deal with Disassembler, VTune, Forte, JvmtiExport, MemoryService.
382   static void trace_new_stub(RuntimeBlob* blob, const char* name1, const char* name2 = "");
383 };
384 
385 class WhiteBox;
386 //----------------------------------------------------------------------------------------------------
387 // BufferBlob: used to hold non-relocatable machine code such as the interpreter, stubroutines, etc.
388 
389 class BufferBlob: public RuntimeBlob {
390   friend class VMStructs;
391   friend class AdapterBlob;
392   friend class VtableBlob;
393   friend class MethodHandlesAdapterBlob;
394   friend class WhiteBox;
395 
396  private:
397   // Creation support
398   BufferBlob(const char* name, int size);
399   BufferBlob(const char* name, int size, CodeBuffer* cb);
400 
401   // This ordinary operator delete is needed even though not used, so the
402   // below two-argument operator delete will be treated as a placement
403   // delete rather than an ordinary sized delete; see C++14 3.7.4.2/p2.
404   void operator delete(void* p);
405   void* operator new(size_t s, unsigned size) throw();
406 
407  public:
408   // Creation
409   static BufferBlob* create(const char* name, int buffer_size);
410   static BufferBlob* create(const char* name, CodeBuffer* cb);
411 
412   static void free(BufferBlob* buf);
413 
414   // Typing
415   virtual bool is_buffer_blob() const            { return true; }
416 
417   // GC/Verification support
418   void preserve_callee_argument_oops(frame fr, const RegisterMap* reg_map, OopClosure* f)  { /* nothing to do */ }
419   bool is_alive() const                          { return true; }
420 
421   void verify();
422   void print_on(outputStream* st) const;
423   void print_value_on(outputStream* st) const;
424 };
425 
426 
427 //----------------------------------------------------------------------------------------------------
428 // AdapterBlob: used to hold C2I/I2C adapters
429 
430 class AdapterBlob: public BufferBlob {
431 private:
432   AdapterBlob(int size, CodeBuffer* cb);
433 
434 public:
435   // Creation
436   static AdapterBlob* create(CodeBuffer* cb);
437 
438   // Typing
439   virtual bool is_adapter_blob() const { return true; }
440 };
441 
442 //---------------------------------------------------------------------------------------------------
443 class VtableBlob: public BufferBlob {
444 private:
445   VtableBlob(const char*, int);
446 
447 public:
448   // Creation
449   static VtableBlob* create(const char* name, int buffer_size);
450 
451   // Typing
452   virtual bool is_vtable_blob() const { return true; }
453 };
454 
455 //----------------------------------------------------------------------------------------------------
456 // MethodHandlesAdapterBlob: used to hold MethodHandles adapters
457 
458 class MethodHandlesAdapterBlob: public BufferBlob {
459 private:
460   MethodHandlesAdapterBlob(int size)                 : BufferBlob("MethodHandles adapters", size) {}
461 
462 public:
463   // Creation
464   static MethodHandlesAdapterBlob* create(int buffer_size);
465 
466   // Typing
467   virtual bool is_method_handles_adapter_blob() const { return true; }
468 };
469 
470 
471 //----------------------------------------------------------------------------------------------------
472 // RuntimeStub: describes stubs used by compiled code to call a (static) C++ runtime routine
473 
474 class RuntimeStub: public RuntimeBlob {
475   friend class VMStructs;
476  private:
477   // Creation support
478   RuntimeStub(
479     const char* name,
480     CodeBuffer* cb,
481     int         size,
482     int         frame_complete,
483     int         frame_size,
484     OopMapSet*  oop_maps,
485     bool        caller_must_gc_arguments
486   );
487 
488   // This ordinary operator delete is needed even though not used, so the
489   // below two-argument operator delete will be treated as a placement
490   // delete rather than an ordinary sized delete; see C++14 3.7.4.2/p2.
491   void operator delete(void* p);
492   void* operator new(size_t s, unsigned size) throw();
493 
494  public:
495   // Creation
496   static RuntimeStub* new_runtime_stub(
497     const char* stub_name,
498     CodeBuffer* cb,
499     int         frame_complete,
500     int         frame_size,
501     OopMapSet*  oop_maps,
502     bool        caller_must_gc_arguments
503   );
504 
505   // Typing
506   bool is_runtime_stub() const                   { return true; }
507 
508   address entry_point() const                    { return code_begin(); }
509 
510   // GC/Verification support
511   void preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map, OopClosure* f)  { /* nothing to do */ }
512   bool is_alive() const                          { return true; }
513 
514   void verify();
515   void print_on(outputStream* st) const;
516   void print_value_on(outputStream* st) const;
517 };
518 
519 
520 //----------------------------------------------------------------------------------------------------
521 // Super-class for all blobs that exist in only one instance. Implements default behaviour.
522 
523 class SingletonBlob: public RuntimeBlob {
524   friend class VMStructs;
525 
526  protected:
527   // This ordinary operator delete is needed even though not used, so the
528   // below two-argument operator delete will be treated as a placement
529   // delete rather than an ordinary sized delete; see C++14 3.7.4.2/p2.
530   void operator delete(void* p);
531   void* operator new(size_t s, unsigned size) throw();
532 
533  public:
534    SingletonBlob(
535      const char* name,
536      CodeBuffer* cb,
537      int         header_size,
538      int         size,
539      int         frame_size,
540      OopMapSet*  oop_maps
541    )
542    : RuntimeBlob(name, cb, header_size, size, CodeOffsets::frame_never_safe, frame_size, oop_maps)
543   {};
544 
545   address entry_point()                          { return code_begin(); }
546 
547   bool is_alive() const                          { return true; }
548 
549   // GC/Verification support
550   void preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map, OopClosure* f)  { /* nothing to do */ }
551   void verify(); // does nothing
552   void print_on(outputStream* st) const;
553   void print_value_on(outputStream* st) const;
554 };
555 
556 
557 //----------------------------------------------------------------------------------------------------
558 // DeoptimizationBlob
559 
560 class DeoptimizationBlob: public SingletonBlob {
561   friend class VMStructs;
562   friend class JVMCIVMStructs;
563  private:
564   int _unpack_offset;
565   int _unpack_with_exception;
566   int _unpack_with_reexecution;
567 
568   int _unpack_with_exception_in_tls;
569 
570 #if INCLUDE_JVMCI
571   // Offsets when JVMCI calls uncommon_trap.
572   int _uncommon_trap_offset;
573   int _implicit_exception_uncommon_trap_offset;
574 #endif
575 
576   // Creation support
577   DeoptimizationBlob(
578     CodeBuffer* cb,
579     int         size,
580     OopMapSet*  oop_maps,
581     int         unpack_offset,
582     int         unpack_with_exception_offset,
583     int         unpack_with_reexecution_offset,
584     int         frame_size
585   );
586 
587  public:
588   // Creation
589   static DeoptimizationBlob* create(
590     CodeBuffer* cb,
591     OopMapSet*  oop_maps,
592     int         unpack_offset,
593     int         unpack_with_exception_offset,
594     int         unpack_with_reexecution_offset,
595     int         frame_size
596   );
597 
598   // Typing
599   bool is_deoptimization_stub() const { return true; }
600   bool exception_address_is_unpack_entry(address pc) const {
601     address unpack_pc = unpack();
602     return (pc == unpack_pc || (pc + frame::pc_return_offset) == unpack_pc);
603   }
604 
605   // GC for args
606   void preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map, OopClosure* f) { /* Nothing to do */ }
607 
608   // Printing
609   void print_value_on(outputStream* st) const;
610 
611   address unpack() const                         { return code_begin() + _unpack_offset;           }
612   address unpack_with_exception() const          { return code_begin() + _unpack_with_exception;   }
613   address unpack_with_reexecution() const        { return code_begin() + _unpack_with_reexecution; }
614 
615   // Alternate entry point for C1 where the exception and issuing pc
616   // are in JavaThread::_exception_oop and JavaThread::_exception_pc
617   // instead of being in registers.  This is needed because C1 doesn't
618   // model exception paths in a way that keeps these registers free so
619   // there may be live values in those registers during deopt.
620   void set_unpack_with_exception_in_tls_offset(int offset) {
621     _unpack_with_exception_in_tls = offset;
622     assert(code_contains(code_begin() + _unpack_with_exception_in_tls), "must be PC inside codeblob");
623   }
624   address unpack_with_exception_in_tls() const   { return code_begin() + _unpack_with_exception_in_tls; }
625 
626 #if INCLUDE_JVMCI
627   // Offsets when JVMCI calls uncommon_trap.
628   void set_uncommon_trap_offset(int offset) {
629     _uncommon_trap_offset = offset;
630     assert(contains(code_begin() + _uncommon_trap_offset), "must be PC inside codeblob");
631   }
632   address uncommon_trap() const                  { return code_begin() + _uncommon_trap_offset; }
633 
634   void set_implicit_exception_uncommon_trap_offset(int offset) {
635     _implicit_exception_uncommon_trap_offset = offset;
636     assert(contains(code_begin() + _implicit_exception_uncommon_trap_offset), "must be PC inside codeblob");
637   }
638   address implicit_exception_uncommon_trap() const { return code_begin() + _implicit_exception_uncommon_trap_offset; }
639 #endif // INCLUDE_JVMCI
640 };
641 
642 
643 //----------------------------------------------------------------------------------------------------
644 // UncommonTrapBlob (currently only used by Compiler 2)
645 
646 #ifdef COMPILER2
647 
648 class UncommonTrapBlob: public SingletonBlob {
649   friend class VMStructs;
650  private:
651   // Creation support
652   UncommonTrapBlob(
653     CodeBuffer* cb,
654     int         size,
655     OopMapSet*  oop_maps,
656     int         frame_size
657   );
658 
659  public:
660   // Creation
661   static UncommonTrapBlob* create(
662     CodeBuffer* cb,
663     OopMapSet*  oop_maps,
664     int         frame_size
665   );
666 
667   // GC for args
668   void preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map, OopClosure* f)  { /* nothing to do */ }
669 
670   // Typing
671   bool is_uncommon_trap_stub() const             { return true; }
672 };
673 
674 
675 //----------------------------------------------------------------------------------------------------
676 // ExceptionBlob: used for exception unwinding in compiled code (currently only used by Compiler 2)
677 
678 class ExceptionBlob: public SingletonBlob {
679   friend class VMStructs;
680  private:
681   // Creation support
682   ExceptionBlob(
683     CodeBuffer* cb,
684     int         size,
685     OopMapSet*  oop_maps,
686     int         frame_size
687   );
688 
689  public:
690   // Creation
691   static ExceptionBlob* create(
692     CodeBuffer* cb,
693     OopMapSet*  oop_maps,
694     int         frame_size
695   );
696 
697   // GC for args
698   void preserve_callee_argument_oops(frame fr, const RegisterMap* reg_map, OopClosure* f)  { /* nothing to do */ }
699 
700   // Typing
701   bool is_exception_stub() const                 { return true; }
702 };
703 #endif // COMPILER2
704 
705 
706 //----------------------------------------------------------------------------------------------------
707 // SafepointBlob: handles illegal_instruction exceptions during a safepoint
708 
709 class SafepointBlob: public SingletonBlob {
710   friend class VMStructs;
711  private:
712   // Creation support
713   SafepointBlob(
714     CodeBuffer* cb,
715     int         size,
716     OopMapSet*  oop_maps,
717     int         frame_size
718   );
719 
720  public:
721   // Creation
722   static SafepointBlob* create(
723     CodeBuffer* cb,
724     OopMapSet*  oop_maps,
725     int         frame_size
726   );
727 
728   // GC for args
729   void preserve_callee_argument_oops(frame fr, const RegisterMap* reg_map, OopClosure* f)  { /* nothing to do */ }
730 
731   // Typing
732   bool is_safepoint_stub() const                 { return true; }
733 };
734 
735 #endif // SHARE_VM_CODE_CODEBLOB_HPP