1 /*
  2  * Copyright (c) 1997, 2024, 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_ASM_CODEBUFFER_HPP
 26 #define SHARE_ASM_CODEBUFFER_HPP
 27 
 28 #include "code/oopRecorder.hpp"
 29 #include "code/relocInfo.hpp"
 30 #include "compiler/compiler_globals.hpp"
 31 #include "utilities/align.hpp"
 32 #include "utilities/debug.hpp"
 33 #include "utilities/growableArray.hpp"
 34 #include "utilities/linkedlist.hpp"
 35 #include "utilities/resizeableResourceHash.hpp"
 36 #include "utilities/macros.hpp"
 37 
 38 template <typename T>
 39 static inline void put_native(address p, T x) {
 40     memcpy((void*)p, &x, sizeof x);
 41 }
 42 
 43 class PhaseCFG;
 44 class Compile;
 45 class BufferBlob;
 46 class CodeBuffer;
 47 class Label;
 48 class ciMethod;
 49 class SharedStubToInterpRequest;
 50 
 51 class CodeOffsets: public StackObj {
 52 public:
 53   enum Entries { Entry,
 54                  Verified_Entry,
 55                  Inline_Entry,
 56                  Verified_Inline_Entry,
 57                  Verified_Inline_Entry_RO,
 58                  Frame_Complete, // Offset in the code where the frame setup is (for forte stackwalks) is complete
 59                  OSR_Entry,
 60                  Exceptions,     // Offset where exception handler lives
 61                  Deopt,          // Offset where deopt handler lives
 62                  DeoptMH,        // Offset where MethodHandle deopt handler lives
 63                  UnwindHandler,  // Offset to default unwind handler
 64                  max_Entries };
 65 
 66   // special value to note codeBlobs where profile (forte) stack walking is
 67   // always dangerous and suspect.
 68 
 69   enum { frame_never_safe = -1 };
 70 
 71 private:
 72   int _values[max_Entries];
 73   void check(int e) const { assert(0 <= e && e < max_Entries, "must be"); }
 74 
 75 public:
 76   CodeOffsets() {
 77     _values[Entry         ] = 0;
 78     _values[Verified_Entry] = 0;
 79     _values[Inline_Entry  ] = 0;
 80     _values[Verified_Inline_Entry] = -1;
 81     _values[Verified_Inline_Entry_RO] = -1;
 82     _values[Frame_Complete] = frame_never_safe;
 83     _values[OSR_Entry     ] = 0;
 84     _values[Exceptions    ] = -1;
 85     _values[Deopt         ] = -1;
 86     _values[DeoptMH       ] = -1;
 87     _values[UnwindHandler ] = -1;
 88   }
 89 
 90   int value(Entries e) const { check(e); return _values[e]; }
 91   void set_value(Entries e, int val) { check(e); _values[e] = val; }
 92 };
 93 
 94 // This class represents a stream of code and associated relocations.
 95 // There are a few in each CodeBuffer.
 96 // They are filled concurrently, and concatenated at the end.
 97 class CodeSection {
 98   friend class CodeBuffer;
 99  public:
100   typedef int csize_t;  // code size type; would be size_t except for history
101 
102  private:
103   address     _start;           // first byte of contents (instructions)
104   address     _mark;            // user mark, usually an instruction beginning
105   address     _end;             // current end address
106   address     _limit;           // last possible (allocated) end address
107   relocInfo*  _locs_start;      // first byte of relocation information
108   relocInfo*  _locs_end;        // first byte after relocation information
109   relocInfo*  _locs_limit;      // first byte after relocation information buf
110   address     _locs_point;      // last relocated position (grows upward)
111   bool        _locs_own;        // did I allocate the locs myself?
112   bool        _scratch_emit;    // Buffer is used for scratch emit, don't relocate.
113   int         _skipped_instructions_size;
114   int8_t      _index;           // my section number (SECT_INST, etc.)
115   CodeBuffer* _outer;           // enclosing CodeBuffer
116 
117   // (Note:  _locs_point used to be called _last_reloc_offset.)
118 
119   CodeSection() {
120     _start         = nullptr;
121     _mark          = nullptr;
122     _end           = nullptr;
123     _limit         = nullptr;
124     _locs_start    = nullptr;
125     _locs_end      = nullptr;
126     _locs_limit    = nullptr;
127     _locs_point    = nullptr;
128     _locs_own      = false;
129     _scratch_emit  = false;
130     _skipped_instructions_size = 0;
131     debug_only(_index = -1);
132     debug_only(_outer = (CodeBuffer*)badAddress);
133   }
134 
135   void initialize_outer(CodeBuffer* outer, int8_t index) {
136     _outer = outer;
137     _index = index;
138   }
139 
140   void initialize(address start, csize_t size = 0) {
141     assert(_start == nullptr, "only one init step, please");
142     _start         = start;
143     _mark          = nullptr;
144     _end           = start;
145 
146     _limit         = start + size;
147     _locs_point    = start;
148   }
149 
150   void initialize_locs(int locs_capacity);
151   void expand_locs(int new_capacity);
152   void initialize_locs_from(const CodeSection* source_cs);
153 
154   // helper for CodeBuffer::expand()
155   void take_over_code_from(CodeSection* cs) {
156     _start      = cs->_start;
157     _mark       = cs->_mark;
158     _end        = cs->_end;
159     _limit      = cs->_limit;
160     _locs_point = cs->_locs_point;
161     _skipped_instructions_size = cs->_skipped_instructions_size;
162   }
163 
164  public:
165   address     start() const         { return _start; }
166   address     mark() const          { return _mark; }
167   address     end() const           { return _end; }
168   address     limit() const         { return _limit; }
169   csize_t     size() const          { return (csize_t)(_end - _start); }
170   csize_t     mark_off() const      { assert(_mark != nullptr, "not an offset");
171                                       return (csize_t)(_mark - _start); }
172   csize_t     capacity() const      { return (csize_t)(_limit - _start); }
173   csize_t     remaining() const     { return (csize_t)(_limit - _end); }
174 
175   relocInfo*  locs_start() const    { return _locs_start; }
176   relocInfo*  locs_end() const      { return _locs_end; }
177   int         locs_count() const    { return (int)(_locs_end - _locs_start); }
178   relocInfo*  locs_limit() const    { return _locs_limit; }
179   address     locs_point() const    { return _locs_point; }
180   csize_t     locs_point_off() const{ return (csize_t)(_locs_point - _start); }
181   csize_t     locs_capacity() const { return (csize_t)(_locs_limit - _locs_start); }
182 
183   int8_t      index() const         { return _index; }
184   bool        is_allocated() const  { return _start != nullptr; }
185   bool        is_empty() const      { return _start == _end; }
186   bool        has_locs() const      { return _locs_end != nullptr; }
187 
188   // Mark scratch buffer.
189   void        set_scratch_emit()    { _scratch_emit = true; }
190   void        clear_scratch_emit()  { _scratch_emit = false; }
191   bool        scratch_emit()        { return _scratch_emit; }
192 
193   CodeBuffer* outer() const         { return _outer; }
194 
195   // is a given address in this section?  (2nd version is end-inclusive)
196   bool contains(address pc) const   { return pc >= _start && pc <  _end; }
197   bool contains2(address pc) const  { return pc >= _start && pc <= _end; }
198   bool allocates(address pc) const  { return pc >= _start && pc <  _limit; }
199   bool allocates2(address pc) const { return pc >= _start && pc <= _limit; }
200 
201   // checks if two CodeSections are disjoint
202   //
203   // limit is an exclusive address and can be the start of another
204   // section.
205   bool disjoint(CodeSection* cs) const { return cs->_limit <= _start || cs->_start >= _limit; }
206 
207   void    set_end(address pc)       { assert(allocates2(pc), "not in CodeBuffer memory: " INTPTR_FORMAT " <= " INTPTR_FORMAT " <= " INTPTR_FORMAT, p2i(_start), p2i(pc), p2i(_limit)); _end = pc; }
208   void    set_mark(address pc)      { assert(contains2(pc), "not in codeBuffer");
209                                       _mark = pc; }
210   void    set_mark()                { _mark = _end; }
211   void    clear_mark()              { _mark = nullptr; }
212 
213   void    set_locs_end(relocInfo* p) {
214     assert(p <= locs_limit(), "locs data fits in allocated buffer");
215     _locs_end = p;
216   }
217   void    set_locs_point(address pc) {
218     assert(pc >= locs_point(), "relocation addr may not decrease");
219     assert(allocates2(pc),     "relocation addr " INTPTR_FORMAT " must be in this section from " INTPTR_FORMAT " to " INTPTR_FORMAT, p2i(pc), p2i(_start), p2i(_limit));
220     _locs_point = pc;
221   }
222 
223   void register_skipped(int size) {
224     _skipped_instructions_size += size;
225   }
226 
227   // Code emission
228   void emit_int8(uint8_t x1) {
229     address curr = end();
230     *((uint8_t*)  curr++) = x1;
231     set_end(curr);
232   }
233 
234   template <typename T>
235   void emit_native(T x) { put_native(end(), x); set_end(end() + sizeof x); }
236 
237   void emit_int16(uint16_t x) { emit_native(x); }
238   void emit_int16(uint8_t x1, uint8_t x2) {
239     address curr = end();
240     *((uint8_t*)  curr++) = x1;
241     *((uint8_t*)  curr++) = x2;
242     set_end(curr);
243   }
244 
245   void emit_int24(uint8_t x1, uint8_t x2, uint8_t x3)  {
246     address curr = end();
247     *((uint8_t*)  curr++) = x1;
248     *((uint8_t*)  curr++) = x2;
249     *((uint8_t*)  curr++) = x3;
250     set_end(curr);
251   }
252 
253   void emit_int32(uint32_t x) { emit_native(x); }
254   void emit_int32(uint8_t x1, uint8_t x2, uint8_t x3, uint8_t x4)  {
255     address curr = end();
256     *((uint8_t*)  curr++) = x1;
257     *((uint8_t*)  curr++) = x2;
258     *((uint8_t*)  curr++) = x3;
259     *((uint8_t*)  curr++) = x4;
260     set_end(curr);
261   }
262 
263   void emit_int64(uint64_t x)  { emit_native(x); }
264   void emit_float(jfloat  x)   { emit_native(x); }
265   void emit_double(jdouble x)  { emit_native(x); }
266   void emit_address(address x) { emit_native(x); }
267 
268   // Share a scratch buffer for relocinfo.  (Hacky; saves a resource allocation.)
269   void initialize_shared_locs(relocInfo* buf, int length);
270 
271   // Manage labels and their addresses.
272   address target(Label& L, address branch_pc);
273 
274   // Emit a relocation.
275   void relocate(address at, RelocationHolder const& rspec, int format = 0);
276   void relocate(address at,    relocInfo::relocType rtype, int format = 0, jint method_index = 0);
277 
278   int alignment() const;
279 
280   // Slop between sections, used only when allocating temporary BufferBlob buffers.
281   static csize_t end_slop()         { return MAX2((int)sizeof(jdouble), (int)CodeEntryAlignment); }
282 
283   csize_t align_at_start(csize_t off) const {
284     return (csize_t) align_up(off, alignment());
285   }
286 
287   // Ensure there's enough space left in the current section.
288   // Return true if there was an expansion.
289   bool maybe_expand_to_ensure_remaining(csize_t amount);
290 
291 #ifndef PRODUCT
292   void decode();
293   void print(const char* name);
294 #endif //PRODUCT
295 };
296 
297 
298 #ifndef PRODUCT
299 
300 class AsmRemarkCollection;
301 class DbgStringCollection;
302 
303 // The assumption made here is that most code remarks (or comments) added to
304 // the generated assembly code are unique, i.e. there is very little gain in
305 // trying to share the strings between the different offsets tracked in a
306 // buffer (or blob).
307 
308 class AsmRemarks {
309  public:
310   AsmRemarks();
311  ~AsmRemarks();
312 
313   const char* insert(uint offset, const char* remstr);
314 
315   bool is_empty() const;
316 
317   void share(const AsmRemarks &src);
318   void clear();
319   uint print(uint offset, outputStream* strm = tty) const;
320 
321   // For testing purposes only.
322   const AsmRemarkCollection* ref() const { return _remarks; }
323 
324 private:
325   AsmRemarkCollection* _remarks;
326 };
327 
328 // The assumption made here is that the number of debug strings (with a fixed
329 // address requirement) is a rather small set per compilation unit.
330 
331 class DbgStrings {
332  public:
333   DbgStrings();
334  ~DbgStrings();
335 
336   const char* insert(const char* dbgstr);
337 
338   bool is_empty() const;
339 
340   void share(const DbgStrings &src);
341   void clear();
342 
343   // For testing purposes only.
344   const DbgStringCollection* ref() const { return _strings; }
345 
346 private:
347   DbgStringCollection* _strings;
348 };
349 #endif // not PRODUCT
350 
351 
352 #ifdef ASSERT
353 #include "utilities/copy.hpp"
354 
355 class Scrubber {
356  public:
357   Scrubber(void* addr, size_t size) : _addr(addr), _size(size) {}
358  ~Scrubber() {
359     Copy::fill_to_bytes(_addr, _size, badResourceValue);
360   }
361  private:
362   void*  _addr;
363   size_t _size;
364 };
365 #endif // ASSERT
366 
367 typedef GrowableArray<SharedStubToInterpRequest> SharedStubToInterpRequests;
368 
369 // A CodeBuffer describes a memory space into which assembly
370 // code is generated.  This memory space usually occupies the
371 // interior of a single BufferBlob, but in some cases it may be
372 // an arbitrary span of memory, even outside the code cache.
373 //
374 // A code buffer comes in two variants:
375 //
376 // (1) A CodeBuffer referring to an already allocated piece of memory:
377 //     This is used to direct 'static' code generation (e.g. for interpreter
378 //     or stubroutine generation, etc.).  This code comes with NO relocation
379 //     information.
380 //
381 // (2) A CodeBuffer referring to a piece of memory allocated when the
382 //     CodeBuffer is allocated.  This is used for nmethod generation.
383 //
384 // The memory can be divided up into several parts called sections.
385 // Each section independently accumulates code (or data) an relocations.
386 // Sections can grow (at the expense of a reallocation of the BufferBlob
387 // and recopying of all active sections).  When the buffered code is finally
388 // written to an nmethod (or other CodeBlob), the contents (code, data,
389 // and relocations) of the sections are padded to an alignment and concatenated.
390 // Instructions and data in one section can contain relocatable references to
391 // addresses in a sibling section.
392 
393 class CodeBuffer: public StackObj DEBUG_ONLY(COMMA private Scrubber) {
394   friend class CodeSection;
395   friend class StubCodeGenerator;
396 
397  private:
398   // CodeBuffers must be allocated on the stack except for a single
399   // special case during expansion which is handled internally.  This
400   // is done to guarantee proper cleanup of resources.
401   void* operator new(size_t size) throw() { return resource_allocate_bytes(size); }
402   void  operator delete(void* p)          { ShouldNotCallThis(); }
403 
404  public:
405   typedef int csize_t;  // code size type; would be size_t except for history
406   enum : int8_t {
407     // Here is the list of all possible sections.  The order reflects
408     // the final layout.
409     SECT_FIRST = 0,
410     SECT_CONSTS = SECT_FIRST, // Non-instruction data:  Floats, jump tables, etc.
411     SECT_INSTS,               // Executable instructions.
412     SECT_STUBS,               // Outbound trampolines for supporting call sites.
413     SECT_LIMIT, SECT_NONE = -1
414   };
415 
416   typedef LinkedListImpl<int> Offsets;
417   typedef ResizeableResourceHashtable<address, Offsets, AnyObj::C_HEAP, mtCompiler> SharedTrampolineRequests;
418 
419  private:
420   enum {
421     sect_bits = 2,      // assert (SECT_LIMIT <= (1<<sect_bits))
422     sect_mask = (1<<sect_bits)-1
423   };
424 
425   const char*  _name;
426 
427   CodeSection  _consts;             // constants, jump tables
428   CodeSection  _insts;              // instructions (the main section)
429   CodeSection  _stubs;              // stubs (call site support), deopt, exception handling
430 
431   CodeBuffer*  _before_expand;  // dead buffer, from before the last expansion
432 
433   BufferBlob*  _blob;           // optional buffer in CodeCache for generated code
434   address      _total_start;    // first address of combined memory buffer
435   csize_t      _total_size;     // size in bytes of combined memory buffer
436 
437   OopRecorder* _oop_recorder;
438 
439   OopRecorder  _default_oop_recorder;  // override with initialize_oop_recorder
440   Arena*       _overflow_arena;
441 
442   address      _last_insn;      // used to merge consecutive memory barriers, loads or stores.
443   address      _last_label;     // record last bind label address, it's also the start of current bb.
444 
445   SharedStubToInterpRequests* _shared_stub_to_interp_requests; // used to collect requests for shared iterpreter stubs
446   SharedTrampolineRequests*   _shared_trampoline_requests;     // used to collect requests for shared trampolines
447   bool         _finalize_stubs; // Indicate if we need to finalize stubs to make CodeBuffer final.
448 
449   int          _const_section_alignment;
450 
451 #ifndef PRODUCT
452   AsmRemarks   _asm_remarks;
453   DbgStrings   _dbg_strings;
454   bool         _collect_comments; // Indicate if we need to collect block comments at all.
455   address      _decode_begin;     // start address for decode
456   address      decode_begin();
457 #endif
458 
459   void initialize_misc(const char * name) {
460     // all pointers other than code_start/end and those inside the sections
461     assert(name != nullptr, "must have a name");
462     _name            = name;
463     _before_expand   = nullptr;
464     _blob            = nullptr;
465     _oop_recorder    = nullptr;
466     _overflow_arena  = nullptr;
467     _last_insn       = nullptr;
468     _last_label      = nullptr;
469     _finalize_stubs  = false;
470     _shared_stub_to_interp_requests = nullptr;
471     _shared_trampoline_requests = nullptr;
472 
473     _consts.initialize_outer(this, SECT_CONSTS);
474     _insts.initialize_outer(this,  SECT_INSTS);
475     _stubs.initialize_outer(this,  SECT_STUBS);
476 
477     // Default is to align on 8 bytes. A compiler can change this
478     // if larger alignment (e.g., 32-byte vector masks) is required.
479     _const_section_alignment = (int) sizeof(jdouble);
480 
481 #ifndef PRODUCT
482     _decode_begin    = nullptr;
483     // Collect block comments, but restrict collection to cases where a disassembly is output.
484     _collect_comments = ( PrintAssembly
485                        || PrintStubCode
486                        || PrintMethodHandleStubs
487                        || PrintInterpreter
488                        || PrintSignatureHandlers
489                        || UnlockDiagnosticVMOptions
490                         );
491 #endif
492   }
493 
494   void initialize(address code_start, csize_t code_size) {
495     _total_start = code_start;
496     _total_size  = code_size;
497     // Initialize the main section:
498     _insts.initialize(code_start, code_size);
499     assert(!_stubs.is_allocated(),  "no garbage here");
500     assert(!_consts.is_allocated(), "no garbage here");
501     _oop_recorder = &_default_oop_recorder;
502   }
503 
504   void initialize_section_size(CodeSection* cs, csize_t size);
505 
506   // helper for CodeBuffer::expand()
507   void take_over_code_from(CodeBuffer* cs);
508 
509   // ensure sections are disjoint, ordered, and contained in the blob
510   void verify_section_allocation();
511 
512   // copies combined relocations to the blob, returns bytes copied
513   // (if target is null, it is a dry run only, just for sizing)
514   csize_t copy_relocations_to(CodeBlob* blob) const;
515 
516   // copies combined code to the blob (assumes relocs are already in there)
517   void copy_code_to(CodeBlob* blob);
518 
519   // moves code sections to new buffer (assumes relocs are already in there)
520   void relocate_code_to(CodeBuffer* cb) const;
521 
522   // adjust some internal address during expand
523   void adjust_internal_address(address from, address to);
524 
525   // set up a model of the final layout of my contents
526   void compute_final_layout(CodeBuffer* dest) const;
527 
528   // Expand the given section so at least 'amount' is remaining.
529   // Creates a new, larger BufferBlob, and rewrites the code & relocs.
530   void expand(CodeSection* which_cs, csize_t amount);
531 
532   // Helper for expand.
533   csize_t figure_expanded_capacities(CodeSection* which_cs, csize_t amount, csize_t* new_capacity);
534 
535  public:
536   // (1) code buffer referring to pre-allocated instruction memory
537   CodeBuffer(address code_start, csize_t code_size)
538     DEBUG_ONLY(: Scrubber(this, sizeof(*this)))
539   {
540     assert(code_start != nullptr, "sanity");
541     initialize_misc("static buffer");
542     initialize(code_start, code_size);
543     debug_only(verify_section_allocation();)
544   }
545 
546   // (2) CodeBuffer referring to pre-allocated CodeBlob.
547   CodeBuffer(CodeBlob* blob);
548 
549   // (3) code buffer allocating codeBlob memory for code & relocation
550   // info but with lazy initialization.  The name must be something
551   // informative.
552   CodeBuffer(const char* name)
553     DEBUG_ONLY(: Scrubber(this, sizeof(*this)))
554   {
555     initialize_misc(name);
556   }
557 
558   // (4) code buffer allocating codeBlob memory for code & relocation
559   // info.  The name must be something informative and code_size must
560   // include both code and stubs sizes.
561   CodeBuffer(const char* name, csize_t code_size, csize_t locs_size)
562     DEBUG_ONLY(: Scrubber(this, sizeof(*this)))
563   {
564     initialize_misc(name);
565     initialize(code_size, locs_size);
566   }
567 
568   ~CodeBuffer();
569 
570   // Initialize a CodeBuffer constructed using constructor 3.  Using
571   // constructor 4 is equivalent to calling constructor 3 and then
572   // calling this method.  It's been factored out for convenience of
573   // construction.
574   void initialize(csize_t code_size, csize_t locs_size);
575 
576   CodeSection* consts() { return &_consts; }
577   CodeSection* insts() { return &_insts; }
578   CodeSection* stubs() { return &_stubs; }
579 
580   const CodeSection* insts() const { return &_insts; }
581 
582   // present sections in order; return null at end; consts is #0, etc.
583   CodeSection* code_section(int n) {
584     // This makes the slightly questionable but portable assumption
585     // that the various members (_consts, _insts, _stubs, etc.) are
586     // adjacent in the layout of CodeBuffer.
587     CodeSection* cs = &_consts + n;
588     assert(cs->index() == n || !cs->is_allocated(), "sanity");
589     return cs;
590   }
591   const CodeSection* code_section(int n) const {  // yucky const stuff
592     return ((CodeBuffer*)this)->code_section(n);
593   }
594   static const char* code_section_name(int n);
595   int section_index_of(address addr) const;
596   bool contains(address addr) const {
597     // handy for debugging
598     return section_index_of(addr) > SECT_NONE;
599   }
600 
601   // A stable mapping between 'locators' (small ints) and addresses.
602   static int locator_pos(int locator)   { return locator >> sect_bits; }
603   static int locator_sect(int locator)  { return locator &  sect_mask; }
604   static int locator(int pos, int sect) { return (pos << sect_bits) | sect; }
605   int        locator(address addr) const;
606   address    locator_address(int locator) const {
607     if (locator < 0)  return nullptr;
608     address start = code_section(locator_sect(locator))->start();
609     return start + locator_pos(locator);
610   }
611 
612   // Heuristic for pre-packing the taken/not-taken bit of a predicted branch.
613   bool is_backward_branch(Label& L);
614 
615   // Properties
616   const char* name() const                  { return _name; }
617   void set_name(const char* name)           { _name = name; }
618   CodeBuffer* before_expand() const         { return _before_expand; }
619   BufferBlob* blob() const                  { return _blob; }
620   void    set_blob(BufferBlob* blob);
621   void   free_blob();                       // Free the blob, if we own one.
622 
623   // Properties relative to the insts section:
624   address       insts_begin() const      { return _insts.start();      }
625   address       insts_end() const        { return _insts.end();        }
626   void      set_insts_end(address end)   {        _insts.set_end(end); }
627   address       insts_mark() const       { return _insts.mark();       }
628   void      set_insts_mark()             {        _insts.set_mark();   }
629 
630   // is there anything in the buffer other than the current section?
631   bool    is_pure() const                { return insts_size() == total_content_size(); }
632 
633   // size in bytes of output so far in the insts sections
634   csize_t insts_size() const             { return _insts.size(); }
635 
636   // same as insts_size(), except that it asserts there is no non-code here
637   csize_t pure_insts_size() const        { assert(is_pure(), "no non-code");
638                                            return insts_size(); }
639   // capacity in bytes of the insts sections
640   csize_t insts_capacity() const         { return _insts.capacity(); }
641 
642   // number of bytes remaining in the insts section
643   csize_t insts_remaining() const        { return _insts.remaining(); }
644 
645   // is a given address in the insts section?  (2nd version is end-inclusive)
646   bool insts_contains(address pc) const  { return _insts.contains(pc); }
647   bool insts_contains2(address pc) const { return _insts.contains2(pc); }
648 
649   // Record any extra oops required to keep embedded metadata alive
650   void finalize_oop_references(const methodHandle& method);
651 
652   // Allocated size in all sections, when aligned and concatenated
653   // (this is the eventual state of the content in its final
654   // CodeBlob).
655   csize_t total_content_size() const;
656 
657   // Combined offset (relative to start of first section) of given
658   // section, as eventually found in the final CodeBlob.
659   csize_t total_offset_of(const CodeSection* cs) const;
660 
661   // allocated size of all relocation data, including index, rounded up
662   csize_t total_relocation_size() const;
663 
664   int total_skipped_instructions_size() const;
665 
666   csize_t copy_relocations_to(address buf, csize_t buf_limit, bool only_inst) const;
667 
668   // allocated size of any and all recorded oops
669   csize_t total_oop_size() const {
670     OopRecorder* recorder = oop_recorder();
671     return (recorder == nullptr)? 0: recorder->oop_size();
672   }
673 
674   // allocated size of any and all recorded metadata
675   csize_t total_metadata_size() const {
676     OopRecorder* recorder = oop_recorder();
677     return (recorder == nullptr)? 0: recorder->metadata_size();
678   }
679 
680   // Configuration functions, called immediately after the CB is constructed.
681   // The section sizes are subtracted from the original insts section.
682   // Note:  Call them in reverse section order, because each steals from insts.
683   void initialize_consts_size(csize_t size)            { initialize_section_size(&_consts,  size); }
684   void initialize_stubs_size(csize_t size)             { initialize_section_size(&_stubs,   size); }
685   // Override default oop recorder.
686   void initialize_oop_recorder(OopRecorder* r);
687 
688   OopRecorder* oop_recorder() const { return _oop_recorder; }
689 
690   address last_insn() const { return _last_insn; }
691   void set_last_insn(address a) { _last_insn = a; }
692   void clear_last_insn() { set_last_insn(nullptr); }
693 
694   address last_label() const { return _last_label; }
695   void set_last_label(address a) { _last_label = a; }
696 
697 #ifndef PRODUCT
698   AsmRemarks &asm_remarks() { return _asm_remarks; }
699   DbgStrings &dbg_strings() { return _dbg_strings; }
700 
701   void clear_strings() {
702     _asm_remarks.clear();
703     _dbg_strings.clear();
704   }
705 #endif
706 
707   // Code generation
708   void relocate(address at, RelocationHolder const& rspec, int format = 0) {
709     _insts.relocate(at, rspec, format);
710   }
711   void relocate(address at,    relocInfo::relocType rtype, int format = 0) {
712     _insts.relocate(at, rtype, format);
713   }
714 
715   // Management of overflow storage for binding of Labels.
716   GrowableArray<int>* create_patch_overflow();
717 
718   // NMethod generation
719   void copy_code_and_locs_to(CodeBlob* blob) {
720     assert(blob != nullptr, "sane");
721     copy_relocations_to(blob);
722     copy_code_to(blob);
723   }
724   void copy_values_to(nmethod* nm) {
725     if (!oop_recorder()->is_unused()) {
726       oop_recorder()->copy_values_to(nm);
727     }
728   }
729 
730   void block_comment(ptrdiff_t offset, const char* comment) PRODUCT_RETURN;
731   const char* code_string(const char* str) PRODUCT_RETURN_(return nullptr;);
732 
733   // Log a little info about section usage in the CodeBuffer
734   void log_section_sizes(const char* name);
735 
736   // Make a set of stubs final. It can create/optimize stubs.
737   bool finalize_stubs();
738 
739   // Request for a shared stub to the interpreter
740   void shared_stub_to_interp_for(ciMethod* callee, csize_t call_offset);
741 
742   void set_const_section_alignment(int align) {
743     _const_section_alignment = align_up(align, HeapWordSize);
744   }
745 
746 #ifndef PRODUCT
747  public:
748   // Printing / Decoding
749   // decodes from decode_begin() to code_end() and sets decode_begin to end
750   void    decode();
751   void    print();
752 #endif
753   // Directly disassemble code buffer.
754   void    decode(address start, address end);
755 
756   // The following header contains architecture-specific implementations
757 #include CPU_HEADER(codeBuffer)
758 
759 };
760 
761 // A Java method can have calls of Java methods which can be statically bound.
762 // Calls of Java methods need stubs to the interpreter. Calls sharing the same Java method
763 // can share a stub to the interpreter.
764 // A SharedStubToInterpRequest is a request for a shared stub to the interpreter.
765 class SharedStubToInterpRequest : public ResourceObj {
766  private:
767   ciMethod* _shared_method;
768   CodeBuffer::csize_t _call_offset; // The offset of the call in CodeBuffer
769 
770  public:
771   SharedStubToInterpRequest(ciMethod* method = nullptr, CodeBuffer::csize_t call_offset = -1) : _shared_method(method),
772       _call_offset(call_offset) {}
773 
774   ciMethod* shared_method() const { return _shared_method; }
775   CodeBuffer::csize_t call_offset() const { return _call_offset; }
776 };
777 
778 inline bool CodeSection::maybe_expand_to_ensure_remaining(csize_t amount) {
779   if (remaining() < amount) { _outer->expand(this, amount); return true; }
780   return false;
781 }
782 
783 #endif // SHARE_ASM_CODEBUFFER_HPP