1 /*
   2  * Copyright (c) 1997, 2014, 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_ASM_CODEBUFFER_HPP
  26 #define SHARE_VM_ASM_CODEBUFFER_HPP
  27 
  28 #include "code/oopRecorder.hpp"
  29 #include "code/relocInfo.hpp"
  30 #include "utilities/debug.hpp"
  31 
  32 class CodeStrings;
  33 class PhaseCFG;
  34 class Compile;
  35 class BufferBlob;
  36 class CodeBuffer;
  37 class Label;
  38 
  39 class CodeOffsets: public StackObj {
  40 public:
  41   enum Entries { Entry,
  42                  Verified_Entry,
  43                  Frame_Complete, // Offset in the code where the frame setup is (for forte stackwalks) is complete
  44                  OSR_Entry,
  45                  Dtrace_trap = OSR_Entry,  // dtrace probes can never have an OSR entry so reuse it
  46                  Exceptions,     // Offset where exception handler lives
  47                  Deopt,          // Offset where deopt handler lives
  48                  DeoptMH,        // Offset where MethodHandle deopt handler lives
  49                  UnwindHandler,  // Offset to default unwind handler
  50                  max_Entries };
  51 
  52   // special value to note codeBlobs where profile (forte) stack walking is
  53   // always dangerous and suspect.
  54 
  55   enum { frame_never_safe = -1 };
  56 
  57 private:
  58   int _values[max_Entries];
  59 
  60 public:
  61   CodeOffsets() {
  62     _values[Entry         ] = 0;
  63     _values[Verified_Entry] = 0;
  64     _values[Frame_Complete] = frame_never_safe;
  65     _values[OSR_Entry     ] = 0;
  66     _values[Exceptions    ] = -1;
  67     _values[Deopt         ] = -1;
  68     _values[DeoptMH       ] = -1;
  69     _values[UnwindHandler ] = -1;
  70   }
  71 
  72   int value(Entries e) { return _values[e]; }
  73   void set_value(Entries e, int val) { _values[e] = val; }
  74 };
  75 
  76 // This class represents a stream of code and associated relocations.
  77 // There are a few in each CodeBuffer.
  78 // They are filled concurrently, and concatenated at the end.
  79 class CodeSection VALUE_OBJ_CLASS_SPEC {
  80   friend class CodeBuffer;
  81  public:
  82   typedef int csize_t;  // code size type; would be size_t except for history
  83 
  84  private:
  85   address     _start;           // first byte of contents (instructions)
  86   address     _mark;            // user mark, usually an instruction beginning
  87   address     _end;             // current end address
  88   address     _limit;           // last possible (allocated) end address
  89   relocInfo*  _locs_start;      // first byte of relocation information
  90   relocInfo*  _locs_end;        // first byte after relocation information
  91   relocInfo*  _locs_limit;      // first byte after relocation information buf
  92   address     _locs_point;      // last relocated position (grows upward)
  93   bool        _locs_own;        // did I allocate the locs myself?
  94   bool        _frozen;          // no more expansion of this section
  95   char        _index;           // my section number (SECT_INST, etc.)
  96   CodeBuffer* _outer;           // enclosing CodeBuffer
  97 
  98   // (Note:  _locs_point used to be called _last_reloc_offset.)
  99 
 100   CodeSection() {
 101     _start         = NULL;
 102     _mark          = NULL;
 103     _end           = NULL;
 104     _limit         = NULL;
 105     _locs_start    = NULL;
 106     _locs_end      = NULL;
 107     _locs_limit    = NULL;
 108     _locs_point    = NULL;
 109     _locs_own      = false;
 110     _frozen        = false;
 111     debug_only(_index = (char)-1);
 112     debug_only(_outer = (CodeBuffer*)badAddress);
 113   }
 114 
 115   void initialize_outer(CodeBuffer* outer, int index) {
 116     _outer = outer;
 117     _index = index;
 118   }
 119 
 120   void initialize(address start, csize_t size = 0) {
 121     assert(_start == NULL, "only one init step, please");
 122     _start         = start;
 123     _mark          = NULL;
 124     _end           = start;
 125 
 126     _limit         = start + size;
 127     _locs_point    = start;
 128   }
 129 
 130   void initialize_locs(int locs_capacity);
 131   void expand_locs(int new_capacity);
 132   void initialize_locs_from(const CodeSection* source_cs);
 133 
 134   // helper for CodeBuffer::expand()
 135   void take_over_code_from(CodeSection* cs) {
 136     _start      = cs->_start;
 137     _mark       = cs->_mark;
 138     _end        = cs->_end;
 139     _limit      = cs->_limit;
 140     _locs_point = cs->_locs_point;
 141   }
 142 
 143  public:
 144   address     start() const         { return _start; }
 145   address     mark() const          { return _mark; }
 146   address     end() const           { return _end; }
 147   address     limit() const         { return _limit; }
 148   csize_t     size() const          { return (csize_t)(_end - _start); }
 149   csize_t     mark_off() const      { assert(_mark != NULL, "not an offset");
 150                                       return (csize_t)(_mark - _start); }
 151   csize_t     capacity() const      { return (csize_t)(_limit - _start); }
 152   csize_t     remaining() const     { return (csize_t)(_limit - _end); }
 153 
 154   relocInfo*  locs_start() const    { return _locs_start; }
 155   relocInfo*  locs_end() const      { return _locs_end; }
 156   int         locs_count() const    { return (int)(_locs_end - _locs_start); }
 157   relocInfo*  locs_limit() const    { return _locs_limit; }
 158   address     locs_point() const    { return _locs_point; }
 159   csize_t     locs_point_off() const{ return (csize_t)(_locs_point - _start); }
 160   csize_t     locs_capacity() const { return (csize_t)(_locs_limit - _locs_start); }
 161   csize_t     locs_remaining()const { return (csize_t)(_locs_limit - _locs_end); }
 162 
 163   int         index() const         { return _index; }
 164   bool        is_allocated() const  { return _start != NULL; }
 165   bool        is_empty() const      { return _start == _end; }
 166   bool        is_frozen() const     { return _frozen; }
 167   bool        has_locs() const      { return _locs_end != NULL; }
 168 
 169   CodeBuffer* outer() const         { return _outer; }
 170 
 171   // is a given address in this section?  (2nd version is end-inclusive)
 172   bool contains(address pc) const   { return pc >= _start && pc <  _end; }
 173   bool contains2(address pc) const  { return pc >= _start && pc <= _end; }
 174   bool allocates(address pc) const  { return pc >= _start && pc <  _limit; }
 175   bool allocates2(address pc) const { return pc >= _start && pc <= _limit; }
 176 
 177   void    set_end(address pc)       { assert(allocates2(pc), err_msg("not in CodeBuffer memory: " INTPTR_FORMAT " <= " INTPTR_FORMAT " <= " INTPTR_FORMAT, p2i(_start), p2i(pc), p2i(_limit))); _end = pc; }
 178   void    set_mark(address pc)      { assert(contains2(pc), "not in codeBuffer");
 179                                       _mark = pc; }
 180   void    set_mark_off(int offset)  { assert(contains2(offset+_start),"not in codeBuffer");
 181                                       _mark = offset + _start; }
 182   void    set_mark()                { _mark = _end; }
 183   void    clear_mark()              { _mark = NULL; }
 184 
 185   void    set_locs_end(relocInfo* p) {
 186     assert(p <= locs_limit(), "locs data fits in allocated buffer");
 187     _locs_end = p;
 188   }
 189   void    set_locs_point(address pc) {
 190     assert(pc >= locs_point(), "relocation addr may not decrease");
 191     assert(allocates2(pc),     "relocation addr must be in this section");
 192     _locs_point = pc;
 193   }
 194 
 195   // Code emission
 196   void emit_int8 ( int8_t  x)  { *((int8_t*)  end()) = x; set_end(end() + sizeof(int8_t)); }
 197   void emit_int16( int16_t x)  { *((int16_t*) end()) = x; set_end(end() + sizeof(int16_t)); }
 198   void emit_int32( int32_t x)  { *((int32_t*) end()) = x; set_end(end() + sizeof(int32_t)); }
 199   void emit_int64( int64_t x)  { *((int64_t*) end()) = x; set_end(end() + sizeof(int64_t)); }
 200 
 201   void emit_float( jfloat  x)  { *((jfloat*)  end()) = x; set_end(end() + sizeof(jfloat)); }
 202   void emit_double(jdouble x)  { *((jdouble*) end()) = x; set_end(end() + sizeof(jdouble)); }
 203   void emit_address(address x) { *((address*) end()) = x; set_end(end() + sizeof(address)); }
 204 
 205   // Share a scratch buffer for relocinfo.  (Hacky; saves a resource allocation.)
 206   void initialize_shared_locs(relocInfo* buf, int length);
 207 
 208   // Manage labels and their addresses.
 209   address target(Label& L, address branch_pc);
 210 
 211   // Emit a relocation.
 212   void relocate(address at, RelocationHolder const& rspec, int format = 0);
 213   void relocate(address at,    relocInfo::relocType rtype, int format = 0) {
 214     if (rtype != relocInfo::none)
 215       relocate(at, Relocation::spec_simple(rtype), format);
 216   }
 217 
 218   // alignment requirement for starting offset
 219   // Requirements are that the instruction area and the
 220   // stubs area must start on CodeEntryAlignment, and
 221   // the ctable on sizeof(jdouble)
 222   int alignment() const             { return MAX2((int)sizeof(jdouble), (int)CodeEntryAlignment); }
 223 
 224   // Slop between sections, used only when allocating temporary BufferBlob buffers.
 225   static csize_t end_slop()         { return MAX2((int)sizeof(jdouble), (int)CodeEntryAlignment); }
 226 
 227   csize_t align_at_start(csize_t off) const { return (csize_t) align_size_up(off, alignment()); }
 228 
 229   // Mark a section frozen.  Assign its remaining space to
 230   // the following section.  It will never expand after this point.
 231   inline void freeze();         //  { _outer->freeze_section(this); }
 232 
 233   // Ensure there's enough space left in the current section.
 234   // Return true if there was an expansion.
 235   bool maybe_expand_to_ensure_remaining(csize_t amount);
 236 
 237 #ifndef PRODUCT
 238   void decode();
 239   void dump();
 240   void print(const char* name);
 241 #endif //PRODUCT
 242 };
 243 
 244 class CodeString;
 245 class CodeStrings VALUE_OBJ_CLASS_SPEC {
 246 private:
 247 #ifndef PRODUCT
 248   CodeString* _strings;
 249   // Becomes true after copy-out, forbids further use.
 250   bool _defunct; // Zero bit pattern is "valid", see memset call in decode_env::decode_env
 251 #endif
 252 
 253   CodeString* find(intptr_t offset) const;
 254   CodeString* find_last(intptr_t offset) const;
 255 
 256   void set_null_and_invalidate() {
 257 #ifdef ASSERT
 258     _strings = NULL;
 259     _defunct = true;
 260 #endif
 261   }
 262 
 263 public:
 264   CodeStrings() {
 265 #ifndef PRODUCT
 266     _strings = NULL;
 267     _defunct = false;
 268 #endif
 269   }
 270 
 271   bool isNull() {
 272 #ifdef ASSERT
 273     return _strings == NULL;
 274 #else
 275     return true;
 276 #endif
 277   }
 278 
 279   const char* add_string(const char * string) PRODUCT_RETURN_(return NULL;);
 280 
 281   void add_comment(intptr_t offset, const char * comment) PRODUCT_RETURN;
 282   void print_block_comment(outputStream* stream, intptr_t offset) const PRODUCT_RETURN;
 283   // MOVE strings from other to this; invalidate other.
 284   void assign(CodeStrings& other)  PRODUCT_RETURN;
 285   // COPY strings from other to this; leave other valid.
 286   void copy(CodeStrings& other)  PRODUCT_RETURN;
 287   void free() PRODUCT_RETURN;
 288   // Guarantee that _strings are used at most once; assign invalidates a buffer.
 289   inline void check_valid() const {
 290 #ifdef ASSERT
 291     assert(!_defunct, "Use of invalid CodeStrings");
 292 #endif
 293   }
 294 };
 295 
 296 // A CodeBuffer describes a memory space into which assembly
 297 // code is generated.  This memory space usually occupies the
 298 // interior of a single BufferBlob, but in some cases it may be
 299 // an arbitrary span of memory, even outside the code cache.
 300 //
 301 // A code buffer comes in two variants:
 302 //
 303 // (1) A CodeBuffer referring to an already allocated piece of memory:
 304 //     This is used to direct 'static' code generation (e.g. for interpreter
 305 //     or stubroutine generation, etc.).  This code comes with NO relocation
 306 //     information.
 307 //
 308 // (2) A CodeBuffer referring to a piece of memory allocated when the
 309 //     CodeBuffer is allocated.  This is used for nmethod generation.
 310 //
 311 // The memory can be divided up into several parts called sections.
 312 // Each section independently accumulates code (or data) an relocations.
 313 // Sections can grow (at the expense of a reallocation of the BufferBlob
 314 // and recopying of all active sections).  When the buffered code is finally
 315 // written to an nmethod (or other CodeBlob), the contents (code, data,
 316 // and relocations) of the sections are padded to an alignment and concatenated.
 317 // Instructions and data in one section can contain relocatable references to
 318 // addresses in a sibling section.
 319 
 320 class CodeBuffer: public StackObj {
 321   friend class CodeSection;
 322 
 323  private:
 324   // CodeBuffers must be allocated on the stack except for a single
 325   // special case during expansion which is handled internally.  This
 326   // is done to guarantee proper cleanup of resources.
 327   void* operator new(size_t size) throw() { return ResourceObj::operator new(size); }
 328   void  operator delete(void* p)          { ShouldNotCallThis(); }
 329 
 330  public:
 331   typedef int csize_t;  // code size type; would be size_t except for history
 332   enum {
 333     // Here is the list of all possible sections.  The order reflects
 334     // the final layout.
 335     SECT_FIRST = 0,
 336     SECT_CONSTS = SECT_FIRST, // Non-instruction data:  Floats, jump tables, etc.
 337     SECT_INSTS,               // Executable instructions.
 338     SECT_STUBS,               // Outbound trampolines for supporting call sites.
 339     SECT_LIMIT, SECT_NONE = -1
 340   };
 341 
 342  private:
 343   enum {
 344     sect_bits = 2,      // assert (SECT_LIMIT <= (1<<sect_bits))
 345     sect_mask = (1<<sect_bits)-1
 346   };
 347 
 348   const char*  _name;
 349 
 350   CodeSection  _consts;             // constants, jump tables
 351   CodeSection  _insts;              // instructions (the main section)
 352   CodeSection  _stubs;              // stubs (call site support), deopt, exception handling
 353 
 354   CodeBuffer*  _before_expand;  // dead buffer, from before the last expansion
 355 
 356   BufferBlob*  _blob;           // optional buffer in CodeCache for generated code
 357   address      _total_start;    // first address of combined memory buffer
 358   csize_t      _total_size;     // size in bytes of combined memory buffer
 359 
 360   OopRecorder* _oop_recorder;
 361   CodeStrings  _strings;
 362   OopRecorder  _default_oop_recorder;  // override with initialize_oop_recorder
 363   Arena*       _overflow_arena;
 364 
 365   address      _decode_begin;   // start address for decode
 366   address      decode_begin();
 367 
 368   void initialize_misc(const char * name) {
 369     // all pointers other than code_start/end and those inside the sections
 370     assert(name != NULL, "must have a name");
 371     _name            = name;
 372     _before_expand   = NULL;
 373     _blob            = NULL;
 374     _oop_recorder    = NULL;
 375     _decode_begin    = NULL;
 376     _overflow_arena  = NULL;
 377   }
 378 
 379   void initialize(address code_start, csize_t code_size) {
 380     _consts.initialize_outer(this,  SECT_CONSTS);
 381     _insts.initialize_outer(this,   SECT_INSTS);
 382     _stubs.initialize_outer(this,   SECT_STUBS);
 383     _total_start = code_start;
 384     _total_size  = code_size;
 385     // Initialize the main section:
 386     _insts.initialize(code_start, code_size);
 387     assert(!_stubs.is_allocated(),  "no garbage here");
 388     assert(!_consts.is_allocated(), "no garbage here");
 389     _oop_recorder = &_default_oop_recorder;
 390   }
 391 
 392   void initialize_section_size(CodeSection* cs, csize_t size);
 393 
 394   void freeze_section(CodeSection* cs);
 395 
 396   // helper for CodeBuffer::expand()
 397   void take_over_code_from(CodeBuffer* cs);
 398 
 399   // ensure sections are disjoint, ordered, and contained in the blob
 400   void verify_section_allocation();
 401 
 402   // copies combined relocations to the blob, returns bytes copied
 403   // (if target is null, it is a dry run only, just for sizing)
 404   csize_t copy_relocations_to(CodeBlob* blob) const;
 405 
 406   // copies combined code to the blob (assumes relocs are already in there)
 407   void copy_code_to(CodeBlob* blob);
 408 
 409   // moves code sections to new buffer (assumes relocs are already in there)
 410   void relocate_code_to(CodeBuffer* cb) const;
 411 
 412   // set up a model of the final layout of my contents
 413   void compute_final_layout(CodeBuffer* dest) const;
 414 
 415   // Expand the given section so at least 'amount' is remaining.
 416   // Creates a new, larger BufferBlob, and rewrites the code & relocs.
 417   void expand(CodeSection* which_cs, csize_t amount);
 418 
 419   // Helper for expand.
 420   csize_t figure_expanded_capacities(CodeSection* which_cs, csize_t amount, csize_t* new_capacity);
 421 
 422  public:
 423   // (1) code buffer referring to pre-allocated instruction memory
 424   CodeBuffer(address code_start, csize_t code_size) {
 425     assert(code_start != NULL, "sanity");
 426     initialize_misc("static buffer");
 427     initialize(code_start, code_size);
 428     verify_section_allocation();
 429   }
 430 
 431   // (2) CodeBuffer referring to pre-allocated CodeBlob.
 432   CodeBuffer(CodeBlob* blob);
 433 
 434   // (3) code buffer allocating codeBlob memory for code & relocation
 435   // info but with lazy initialization.  The name must be something
 436   // informative.
 437   CodeBuffer(const char* name) {
 438     initialize_misc(name);
 439   }
 440 
 441 
 442   // (4) code buffer allocating codeBlob memory for code & relocation
 443   // info.  The name must be something informative and code_size must
 444   // include both code and stubs sizes.
 445   CodeBuffer(const char* name, csize_t code_size, csize_t locs_size) {
 446     initialize_misc(name);
 447     initialize(code_size, locs_size);
 448   }
 449 
 450   ~CodeBuffer();
 451 
 452   // Initialize a CodeBuffer constructed using constructor 3.  Using
 453   // constructor 4 is equivalent to calling constructor 3 and then
 454   // calling this method.  It's been factored out for convenience of
 455   // construction.
 456   void initialize(csize_t code_size, csize_t locs_size);
 457 
 458   CodeSection* consts()            { return &_consts; }
 459   CodeSection* insts()             { return &_insts; }
 460   CodeSection* stubs()             { return &_stubs; }
 461 
 462   // present sections in order; return NULL at end; consts is #0, etc.
 463   CodeSection* code_section(int n) {
 464     // This makes the slightly questionable but portable assumption
 465     // that the various members (_consts, _insts, _stubs, etc.) are
 466     // adjacent in the layout of CodeBuffer.
 467     CodeSection* cs = &_consts + n;
 468     assert(cs->index() == n || !cs->is_allocated(), "sanity");
 469     return cs;
 470   }
 471   const CodeSection* code_section(int n) const {  // yucky const stuff
 472     return ((CodeBuffer*)this)->code_section(n);
 473   }
 474   static const char* code_section_name(int n);
 475   int section_index_of(address addr) const;
 476   bool contains(address addr) const {
 477     // handy for debugging
 478     return section_index_of(addr) > SECT_NONE;
 479   }
 480 
 481   // A stable mapping between 'locators' (small ints) and addresses.
 482   static int locator_pos(int locator)   { return locator >> sect_bits; }
 483   static int locator_sect(int locator)  { return locator &  sect_mask; }
 484   static int locator(int pos, int sect) { return (pos << sect_bits) | sect; }
 485   int        locator(address addr) const;
 486   address    locator_address(int locator) const;
 487 
 488   // Heuristic for pre-packing the taken/not-taken bit of a predicted branch.
 489   bool is_backward_branch(Label& L);
 490 
 491   // Properties
 492   const char* name() const                  { return _name; }
 493   CodeBuffer* before_expand() const         { return _before_expand; }
 494   BufferBlob* blob() const                  { return _blob; }
 495   void    set_blob(BufferBlob* blob);
 496   void   free_blob();                       // Free the blob, if we own one.
 497 
 498   // Properties relative to the insts section:
 499   address       insts_begin() const      { return _insts.start();      }
 500   address       insts_end() const        { return _insts.end();        }
 501   void      set_insts_end(address end)   {        _insts.set_end(end); }
 502   address       insts_limit() const      { return _insts.limit();      }
 503   address       insts_mark() const       { return _insts.mark();       }
 504   void      set_insts_mark()             {        _insts.set_mark();   }
 505   void    clear_insts_mark()             {        _insts.clear_mark(); }
 506 
 507   // is there anything in the buffer other than the current section?
 508   bool    is_pure() const                { return insts_size() == total_content_size(); }
 509 
 510   // size in bytes of output so far in the insts sections
 511   csize_t insts_size() const             { return _insts.size(); }
 512 
 513   // same as insts_size(), except that it asserts there is no non-code here
 514   csize_t pure_insts_size() const        { assert(is_pure(), "no non-code");
 515                                            return insts_size(); }
 516   // capacity in bytes of the insts sections
 517   csize_t insts_capacity() const         { return _insts.capacity(); }
 518 
 519   // number of bytes remaining in the insts section
 520   csize_t insts_remaining() const        { return _insts.remaining(); }
 521 
 522   // is a given address in the insts section?  (2nd version is end-inclusive)
 523   bool insts_contains(address pc) const  { return _insts.contains(pc); }
 524   bool insts_contains2(address pc) const { return _insts.contains2(pc); }
 525 
 526   // Record any extra oops required to keep embedded metadata alive
 527   void finalize_oop_references(methodHandle method);
 528 
 529   // Allocated size in all sections, when aligned and concatenated
 530   // (this is the eventual state of the content in its final
 531   // CodeBlob).
 532   csize_t total_content_size() const;
 533 
 534   // Combined offset (relative to start of first section) of given
 535   // section, as eventually found in the final CodeBlob.
 536   csize_t total_offset_of(CodeSection* cs) const;
 537 
 538   // allocated size of all relocation data, including index, rounded up
 539   csize_t total_relocation_size() const;
 540 
 541   // allocated size of any and all recorded oops
 542   csize_t total_oop_size() const {
 543     OopRecorder* recorder = oop_recorder();
 544     return (recorder == NULL)? 0: recorder->oop_size();
 545   }
 546 
 547   // allocated size of any and all recorded metadata
 548   csize_t total_metadata_size() const {
 549     OopRecorder* recorder = oop_recorder();
 550     return (recorder == NULL)? 0: recorder->metadata_size();
 551   }
 552 
 553   // Configuration functions, called immediately after the CB is constructed.
 554   // The section sizes are subtracted from the original insts section.
 555   // Note:  Call them in reverse section order, because each steals from insts.
 556   void initialize_consts_size(csize_t size)            { initialize_section_size(&_consts,  size); }
 557   void initialize_stubs_size(csize_t size)             { initialize_section_size(&_stubs,   size); }
 558   // Override default oop recorder.
 559   void initialize_oop_recorder(OopRecorder* r);
 560 
 561   OopRecorder* oop_recorder() const   { return _oop_recorder; }
 562   CodeStrings& strings()              { return _strings; }
 563 
 564   void free_strings() {
 565     if (!_strings.isNull()) {
 566       _strings.free(); // sets _strings Null as a side-effect.
 567     }
 568   }
 569 
 570   // Code generation
 571   void relocate(address at, RelocationHolder const& rspec, int format = 0) {
 572     _insts.relocate(at, rspec, format);
 573   }
 574   void relocate(address at,    relocInfo::relocType rtype, int format = 0) {
 575     _insts.relocate(at, rtype, format);
 576   }
 577 
 578   // Management of overflow storage for binding of Labels.
 579   GrowableArray<int>* create_patch_overflow();
 580 
 581   // NMethod generation
 582   void copy_code_and_locs_to(CodeBlob* blob) {
 583     assert(blob != NULL, "sane");
 584     copy_relocations_to(blob);
 585     copy_code_to(blob);
 586   }
 587   void copy_values_to(nmethod* nm) {
 588     if (!oop_recorder()->is_unused()) {
 589       oop_recorder()->copy_values_to(nm);
 590     }
 591   }
 592 
 593   // Transform an address from the code in this code buffer to a specified code buffer
 594   address transform_address(const CodeBuffer &cb, address addr) const;
 595 
 596   void block_comment(intptr_t offset, const char * comment) PRODUCT_RETURN;
 597   const char* code_string(const char* str) PRODUCT_RETURN_(return NULL;);
 598 
 599   // Log a little info about section usage in the CodeBuffer
 600   void log_section_sizes(const char* name);
 601 
 602 #ifndef PRODUCT
 603  public:
 604   // Printing / Decoding
 605   // decodes from decode_begin() to code_end() and sets decode_begin to end
 606   void    decode();
 607   void    decode_all();         // decodes all the code
 608   void    skip_decode();        // sets decode_begin to code_end();
 609   void    print();
 610 #endif
 611 
 612 
 613   // The following header contains architecture-specific implementations
 614 #ifdef TARGET_ARCH_x86
 615 # include "codeBuffer_x86.hpp"
 616 #endif
 617 #ifdef TARGET_ARCH_sparc
 618 # include "codeBuffer_sparc.hpp"
 619 #endif
 620 #ifdef TARGET_ARCH_zero
 621 # include "codeBuffer_zero.hpp"
 622 #endif
 623 #ifdef TARGET_ARCH_arm
 624 # include "codeBuffer_arm.hpp"
 625 #endif
 626 #ifdef TARGET_ARCH_ppc
 627 # include "codeBuffer_ppc.hpp"
 628 #endif
 629 
 630 };
 631 
 632 
 633 inline void CodeSection::freeze() {
 634   _outer->freeze_section(this);
 635 }
 636 
 637 inline bool CodeSection::maybe_expand_to_ensure_remaining(csize_t amount) {
 638   if (remaining() < amount) { _outer->expand(this, amount); return true; }
 639   return false;
 640 }
 641 
 642 #endif // SHARE_VM_ASM_CODEBUFFER_HPP