rev 11647 : 8161258: Simplify including platform files.
Summary: Include patform files with macros cpu_header() etc. Do various cleanups of macro usages. Remove _64/_32 from adlc generated files and platform .hpp files. Merge stubRoutines_x86*.hpp. Remove empty mutex_<os>* files.
Reviewed-by: dholmes, coleenp, kbarrett

   1 /*
   2  * Copyright (c) 1997, 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_RELOCINFO_HPP
  26 #define SHARE_VM_CODE_RELOCINFO_HPP
  27 
  28 #include "memory/allocation.hpp"
  29 #include "runtime/os.hpp"

  30 
  31 class nmethod;
  32 class CompiledMethod;
  33 class Metadata;
  34 class NativeMovConstReg;
  35 
  36 // Types in this file:
  37 //    relocInfo
  38 //      One element of an array of halfwords encoding compressed relocations.
  39 //      Also, the source of relocation types (relocInfo::oop_type, ...).
  40 //    Relocation
  41 //      A flyweight object representing a single relocation.
  42 //      It is fully unpacked from the compressed relocation array.
  43 //    metadata_Relocation, ... (subclasses of Relocation)
  44 //      The location of some type-specific operations (metadata_addr, ...).
  45 //      Also, the source of relocation specs (metadata_Relocation::spec, ...).
  46 //    oop_Relocation, ... (subclasses of Relocation)
  47 //      oops in the code stream (strings, class loaders)
  48 //      Also, the source of relocation specs (oop_Relocation::spec, ...).
  49 //    RelocationHolder
  50 //      A ValueObj type which acts as a union holding a Relocation object.
  51 //      Represents a relocation spec passed into a CodeBuffer during assembly.
  52 //    RelocIterator
  53 //      A StackObj which iterates over the relocations associated with
  54 //      a range of code addresses.  Can be used to operate a copy of code.
  55 //    BoundRelocation
  56 //      An _internal_ type shared by packers and unpackers of relocations.
  57 //      It pastes together a RelocationHolder with some pointers into
  58 //      code and relocInfo streams.
  59 
  60 
  61 // Notes on relocType:
  62 //
  63 // These hold enough information to read or write a value embedded in
  64 // the instructions of an CodeBlob.  They're used to update:
  65 //
  66 //   1) embedded oops     (isOop()          == true)
  67 //   2) inline caches     (isIC()           == true)
  68 //   3) runtime calls     (isRuntimeCall()  == true)
  69 //   4) internal word ref (isInternalWord() == true)
  70 //   5) external word ref (isExternalWord() == true)
  71 //
  72 // when objects move (GC) or if code moves (compacting the code heap).
  73 // They are also used to patch the code (if a call site must change)
  74 //
  75 // A relocInfo is represented in 16 bits:
  76 //   4 bits indicating the relocation type
  77 //  12 bits indicating the offset from the previous relocInfo address
  78 //
  79 // The offsets accumulate along the relocInfo stream to encode the
  80 // address within the CodeBlob, which is named RelocIterator::addr().
  81 // The address of a particular relocInfo always points to the first
  82 // byte of the relevant instruction (and not to any of its subfields
  83 // or embedded immediate constants).
  84 //
  85 // The offset value is scaled appropriately for the target machine.
  86 // (See relocInfo_<arch>.hpp for the offset scaling.)
  87 //
  88 // On some machines, there may also be a "format" field which may provide
  89 // additional information about the format of the instruction stream
  90 // at the corresponding code address.  The format value is usually zero.
  91 // Any machine (such as Intel) whose instructions can sometimes contain
  92 // more than one relocatable constant needs format codes to distinguish
  93 // which operand goes with a given relocation.
  94 //
  95 // If the target machine needs N format bits, the offset has 12-N bits,
  96 // the format is encoded between the offset and the type, and the
  97 // relocInfo_<arch>.hpp file has manifest constants for the format codes.
  98 //
  99 // If the type is "data_prefix_tag" then the offset bits are further encoded,
 100 // and in fact represent not a code-stream offset but some inline data.
 101 // The data takes the form of a counted sequence of halfwords, which
 102 // precedes the actual relocation record.  (Clients never see it directly.)
 103 // The interpetation of this extra data depends on the relocation type.
 104 //
 105 // On machines that have 32-bit immediate fields, there is usually
 106 // little need for relocation "prefix" data, because the instruction stream
 107 // is a perfectly reasonable place to store the value.  On machines in
 108 // which 32-bit values must be "split" across instructions, the relocation
 109 // data is the "true" specification of the value, which is then applied
 110 // to some field of the instruction (22 or 13 bits, on SPARC).
 111 //
 112 // Whenever the location of the CodeBlob changes, any PC-relative
 113 // relocations, and any internal_word_type relocations, must be reapplied.
 114 // After the GC runs, oop_type relocations must be reapplied.
 115 //
 116 //
 117 // Here are meanings of the types:
 118 //
 119 // relocInfo::none -- a filler record
 120 //   Value:  none
 121 //   Instruction: The corresponding code address is ignored
 122 //   Data:  Any data prefix and format code are ignored
 123 //   (This means that any relocInfo can be disabled by setting
 124 //   its type to none.  See relocInfo::remove.)
 125 //
 126 // relocInfo::oop_type, relocInfo::metadata_type -- a reference to an oop or meta data
 127 //   Value:  an oop, or else the address (handle) of an oop
 128 //   Instruction types: memory (load), set (load address)
 129 //   Data:  []       an oop stored in 4 bytes of instruction
 130 //          [n]      n is the index of an oop in the CodeBlob's oop pool
 131 //          [[N]n l] and l is a byte offset to be applied to the oop
 132 //          [Nn Ll]  both index and offset may be 32 bits if necessary
 133 //   Here is a special hack, used only by the old compiler:
 134 //          [[N]n 00] the value is the __address__ of the nth oop in the pool
 135 //   (Note that the offset allows optimal references to class variables.)
 136 //
 137 // relocInfo::internal_word_type -- an address within the same CodeBlob
 138 // relocInfo::section_word_type -- same, but can refer to another section
 139 //   Value:  an address in the CodeBlob's code or constants section
 140 //   Instruction types: memory (load), set (load address)
 141 //   Data:  []     stored in 4 bytes of instruction
 142 //          [[L]l] a relative offset (see [About Offsets] below)
 143 //   In the case of section_word_type, the offset is relative to a section
 144 //   base address, and the section number (e.g., SECT_INSTS) is encoded
 145 //   into the low two bits of the offset L.
 146 //
 147 // relocInfo::external_word_type -- a fixed address in the runtime system
 148 //   Value:  an address
 149 //   Instruction types: memory (load), set (load address)
 150 //   Data:  []   stored in 4 bytes of instruction
 151 //          [n]  the index of a "well-known" stub (usual case on RISC)
 152 //          [Ll] a 32-bit address
 153 //
 154 // relocInfo::runtime_call_type -- a fixed subroutine in the runtime system
 155 //   Value:  an address
 156 //   Instruction types: PC-relative call (or a PC-relative branch)
 157 //   Data:  []   stored in 4 bytes of instruction
 158 //
 159 // relocInfo::static_call_type -- a static call
 160 //   Value:  an CodeBlob, a stub, or a fixup routine
 161 //   Instruction types: a call
 162 //   Data:  []
 163 //   The identity of the callee is extracted from debugging information.
 164 //   //%note reloc_3
 165 //
 166 // relocInfo::virtual_call_type -- a virtual call site (which includes an inline
 167 //                                 cache)
 168 //   Value:  an CodeBlob, a stub, the interpreter, or a fixup routine
 169 //   Instruction types: a call, plus some associated set-oop instructions
 170 //   Data:  []       the associated set-oops are adjacent to the call
 171 //          [n]      n is a relative offset to the first set-oop
 172 //          [[N]n l] and l is a limit within which the set-oops occur
 173 //          [Nn Ll]  both n and l may be 32 bits if necessary
 174 //   The identity of the callee is extracted from debugging information.
 175 //
 176 // relocInfo::opt_virtual_call_type -- a virtual call site that is statically bound
 177 //
 178 //    Same info as a static_call_type. We use a special type, so the handling of
 179 //    virtuals and statics are separated.
 180 //
 181 //
 182 //   The offset n points to the first set-oop.  (See [About Offsets] below.)
 183 //   In turn, the set-oop instruction specifies or contains an oop cell devoted
 184 //   exclusively to the IC call, which can be patched along with the call.
 185 //
 186 //   The locations of any other set-oops are found by searching the relocation
 187 //   information starting at the first set-oop, and continuing until all
 188 //   relocations up through l have been inspected.  The value l is another
 189 //   relative offset.  (Both n and l are relative to the call's first byte.)
 190 //
 191 //   The limit l of the search is exclusive.  However, if it points within
 192 //   the call (e.g., offset zero), it is adjusted to point after the call and
 193 //   any associated machine-specific delay slot.
 194 //
 195 //   Since the offsets could be as wide as 32-bits, these conventions
 196 //   put no restrictions whatever upon code reorganization.
 197 //
 198 //   The compiler is responsible for ensuring that transition from a clean
 199 //   state to a monomorphic compiled state is MP-safe.  This implies that
 200 //   the system must respond well to intermediate states where a random
 201 //   subset of the set-oops has been correctly from the clean state
 202 //   upon entry to the VEP of the compiled method.  In the case of a
 203 //   machine (Intel) with a single set-oop instruction, the 32-bit
 204 //   immediate field must not straddle a unit of memory coherence.
 205 //   //%note reloc_3
 206 //
 207 // relocInfo::static_stub_type -- an extra stub for each static_call_type
 208 //   Value:  none
 209 //   Instruction types: a virtual call:  { set_oop; jump; }
 210 //   Data:  [[N]n]  the offset of the associated static_call reloc
 211 //   This stub becomes the target of a static call which must be upgraded
 212 //   to a virtual call (because the callee is interpreted).
 213 //   See [About Offsets] below.
 214 //   //%note reloc_2
 215 //
 216 // relocInfo::poll_[return_]type -- a safepoint poll
 217 //   Value:  none
 218 //   Instruction types: memory load or test
 219 //   Data:  none
 220 //
 221 // For example:
 222 //
 223 //   INSTRUCTIONS                        RELOC: TYPE    PREFIX DATA
 224 //   ------------                               ----    -----------
 225 // sethi      %hi(myObject),  R               oop_type [n(myObject)]
 226 // ld      [R+%lo(myObject)+fldOffset], R2    oop_type [n(myObject) fldOffset]
 227 // add R2, 1, R2
 228 // st  R2, [R+%lo(myObject)+fldOffset]        oop_type [n(myObject) fldOffset]
 229 //%note reloc_1
 230 //
 231 // This uses 4 instruction words, 8 relocation halfwords,
 232 // and an entry (which is sharable) in the CodeBlob's oop pool,
 233 // for a total of 36 bytes.
 234 //
 235 // Note that the compiler is responsible for ensuring the "fldOffset" when
 236 // added to "%lo(myObject)" does not overflow the immediate fields of the
 237 // memory instructions.
 238 //
 239 //
 240 // [About Offsets] Relative offsets are supplied to this module as
 241 // positive byte offsets, but they may be internally stored scaled
 242 // and/or negated, depending on what is most compact for the target
 243 // system.  Since the object pointed to by the offset typically
 244 // precedes the relocation address, it is profitable to store
 245 // these negative offsets as positive numbers, but this decision
 246 // is internal to the relocation information abstractions.
 247 //
 248 
 249 class Relocation;
 250 class CodeBuffer;
 251 class CodeSection;
 252 class RelocIterator;
 253 
 254 class relocInfo VALUE_OBJ_CLASS_SPEC {
 255   friend class RelocIterator;
 256  public:
 257   enum relocType {
 258     none                    =  0, // Used when no relocation should be generated
 259     oop_type                =  1, // embedded oop
 260     virtual_call_type       =  2, // a standard inline cache call for a virtual send
 261     opt_virtual_call_type   =  3, // a virtual call that has been statically bound (i.e., no IC cache)
 262     static_call_type        =  4, // a static send
 263     static_stub_type        =  5, // stub-entry for static send  (takes care of interpreter case)
 264     runtime_call_type       =  6, // call to fixed external routine
 265     external_word_type      =  7, // reference to fixed external address
 266     internal_word_type      =  8, // reference within the current code blob
 267     section_word_type       =  9, // internal, but a cross-section reference
 268     poll_type               = 10, // polling instruction for safepoints
 269     poll_return_type        = 11, // polling instruction for safepoints at return
 270     metadata_type           = 12, // metadata that used to be oops
 271     trampoline_stub_type    = 13, // stub-entry for trampoline
 272     yet_unused_type_1       = 14, // Still unused
 273     data_prefix_tag         = 15, // tag for a prefix (carries data arguments)
 274     type_mask               = 15  // A mask which selects only the above values
 275   };
 276 
 277  protected:
 278   unsigned short _value;
 279 
 280   enum RawBitsToken { RAW_BITS };
 281   relocInfo(relocType type, RawBitsToken ignore, int bits)
 282     : _value((type << nontype_width) + bits) { }
 283 
 284   relocInfo(relocType type, RawBitsToken ignore, int off, int f)
 285     : _value((type << nontype_width) + (off / (unsigned)offset_unit) + (f << offset_width)) { }
 286 
 287  public:
 288   // constructor
 289   relocInfo(relocType type, int offset, int format = 0)
 290 #ifndef ASSERT
 291   {
 292     (*this) = relocInfo(type, RAW_BITS, offset, format);
 293   }
 294 #else
 295   // Put a bunch of assertions out-of-line.
 296   ;
 297 #endif
 298 
 299   #define APPLY_TO_RELOCATIONS(visitor) \
 300     visitor(oop) \
 301     visitor(metadata) \
 302     visitor(virtual_call) \
 303     visitor(opt_virtual_call) \
 304     visitor(static_call) \
 305     visitor(static_stub) \
 306     visitor(runtime_call) \
 307     visitor(external_word) \
 308     visitor(internal_word) \
 309     visitor(poll) \
 310     visitor(poll_return) \
 311     visitor(section_word) \
 312     visitor(trampoline_stub) \
 313 
 314 
 315  public:
 316   enum {
 317     value_width             = sizeof(unsigned short) * BitsPerByte,
 318     type_width              = 4,   // == log2(type_mask+1)
 319     nontype_width           = value_width - type_width,
 320     datalen_width           = nontype_width-1,
 321     datalen_tag             = 1 << datalen_width,  // or-ed into _value
 322     datalen_limit           = 1 << datalen_width,
 323     datalen_mask            = (1 << datalen_width)-1
 324   };
 325 
 326   // accessors
 327  public:
 328   relocType  type()       const { return (relocType)((unsigned)_value >> nontype_width); }
 329   int  format()           const { return format_mask==0? 0: format_mask &
 330                                          ((unsigned)_value >> offset_width); }
 331   int  addr_offset()      const { assert(!is_prefix(), "must have offset");
 332                                   return (_value & offset_mask)*offset_unit; }
 333 
 334  protected:
 335   const short* data()     const { assert(is_datalen(), "must have data");
 336                                   return (const short*)(this + 1); }
 337   int          datalen()  const { assert(is_datalen(), "must have data");
 338                                   return (_value & datalen_mask); }
 339   int         immediate() const { assert(is_immediate(), "must have immed");
 340                                   return (_value & datalen_mask); }
 341  public:
 342   static int addr_unit()        { return offset_unit; }
 343   static int offset_limit()     { return (1 << offset_width) * offset_unit; }
 344 
 345   void set_type(relocType type);
 346   void set_format(int format);
 347 
 348   void remove() { set_type(none); }
 349 
 350  protected:
 351   bool is_none()                const { return type() == none; }
 352   bool is_prefix()              const { return type() == data_prefix_tag; }
 353   bool is_datalen()             const { assert(is_prefix(), "must be prefix");
 354                                         return (_value & datalen_tag) != 0; }
 355   bool is_immediate()           const { assert(is_prefix(), "must be prefix");
 356                                         return (_value & datalen_tag) == 0; }
 357 
 358  public:
 359   // Occasionally records of type relocInfo::none will appear in the stream.
 360   // We do not bother to filter these out, but clients should ignore them.
 361   // These records serve as "filler" in three ways:
 362   //  - to skip large spans of unrelocated code (this is rare)
 363   //  - to pad out the relocInfo array to the required oop alignment
 364   //  - to disable old relocation information which is no longer applicable
 365 
 366   inline friend relocInfo filler_relocInfo();
 367 
 368   // Every non-prefix relocation may be preceded by at most one prefix,
 369   // which supplies 1 or more halfwords of associated data.  Conventionally,
 370   // an int is represented by 0, 1, or 2 halfwords, depending on how
 371   // many bits are required to represent the value.  (In addition,
 372   // if the sole halfword is a 10-bit unsigned number, it is made
 373   // "immediate" in the prefix header word itself.  This optimization
 374   // is invisible outside this module.)
 375 
 376   inline friend relocInfo prefix_relocInfo(int datalen);
 377 
 378  protected:
 379   // an immediate relocInfo optimizes a prefix with one 10-bit unsigned value
 380   static relocInfo immediate_relocInfo(int data0) {
 381     assert(fits_into_immediate(data0), "data0 in limits");
 382     return relocInfo(relocInfo::data_prefix_tag, RAW_BITS, data0);
 383   }
 384   static bool fits_into_immediate(int data0) {
 385     return (data0 >= 0 && data0 < datalen_limit);
 386   }
 387 
 388  public:
 389   // Support routines for compilers.
 390 
 391   // This routine takes an infant relocInfo (unprefixed) and
 392   // edits in its prefix, if any.  It also updates dest.locs_end.
 393   void initialize(CodeSection* dest, Relocation* reloc);
 394 
 395   // This routine updates a prefix and returns the limit pointer.
 396   // It tries to compress the prefix from 32 to 16 bits, and if
 397   // successful returns a reduced "prefix_limit" pointer.
 398   relocInfo* finish_prefix(short* prefix_limit);
 399 
 400   // bit-packers for the data array:
 401 
 402   // As it happens, the bytes within the shorts are ordered natively,
 403   // but the shorts within the word are ordered big-endian.
 404   // This is an arbitrary choice, made this way mainly to ease debugging.
 405   static int data0_from_int(jint x)         { return x >> value_width; }
 406   static int data1_from_int(jint x)         { return (short)x; }
 407   static jint jint_from_data(short* data) {
 408     return (data[0] << value_width) + (unsigned short)data[1];
 409   }
 410 
 411   static jint short_data_at(int n, short* data, int datalen) {
 412     return datalen > n ? data[n] : 0;
 413   }
 414 
 415   static jint jint_data_at(int n, short* data, int datalen) {
 416     return datalen > n+1 ? jint_from_data(&data[n]) : short_data_at(n, data, datalen);
 417   }
 418 
 419   // Update methods for relocation information
 420   // (since code is dynamically patched, we also need to dynamically update the relocation info)
 421   // Both methods takes old_type, so it is able to performe sanity checks on the information removed.
 422   static void change_reloc_info_for_address(RelocIterator *itr, address pc, relocType old_type, relocType new_type);
 423   static void remove_reloc_info_for_address(RelocIterator *itr, address pc, relocType old_type);
 424 
 425   // Machine dependent stuff
 426 #ifdef TARGET_ARCH_x86
 427 # include "relocInfo_x86.hpp"
 428 #endif
 429 #ifdef TARGET_ARCH_sparc
 430 # include "relocInfo_sparc.hpp"
 431 #endif
 432 #ifdef TARGET_ARCH_zero
 433 # include "relocInfo_zero.hpp"
 434 #endif
 435 #ifdef TARGET_ARCH_arm
 436 # include "relocInfo_arm.hpp"
 437 #endif
 438 #ifdef TARGET_ARCH_ppc
 439 # include "relocInfo_ppc.hpp"
 440 #endif
 441 #ifdef TARGET_ARCH_aarch64
 442 # include "relocInfo_aarch64.hpp"
 443 #endif
 444 
 445  protected:
 446   // Derived constant, based on format_width which is PD:
 447   enum {
 448     offset_width       = nontype_width - format_width,
 449     offset_mask        = (1<<offset_width) - 1,
 450     format_mask        = (1<<format_width) - 1
 451   };
 452  public:
 453   enum {
 454 #ifdef _LP64
 455     // for use in format
 456     // format_width must be at least 1 on _LP64
 457     narrow_oop_in_const = 1,
 458 #endif
 459     // Conservatively large estimate of maximum length (in shorts)
 460     // of any relocation record.
 461     // Extended format is length prefix, data words, and tag/offset suffix.
 462     length_limit       = 1 + 1 + (3*BytesPerWord/BytesPerShort) + 1,
 463     have_format        = format_width > 0
 464   };
 465 };
 466 
 467 #define FORWARD_DECLARE_EACH_CLASS(name)              \
 468 class name##_Relocation;
 469 APPLY_TO_RELOCATIONS(FORWARD_DECLARE_EACH_CLASS)
 470 #undef FORWARD_DECLARE_EACH_CLASS
 471 
 472 
 473 
 474 inline relocInfo filler_relocInfo() {
 475   return relocInfo(relocInfo::none, relocInfo::offset_limit() - relocInfo::offset_unit);
 476 }
 477 
 478 inline relocInfo prefix_relocInfo(int datalen = 0) {
 479   assert(relocInfo::fits_into_immediate(datalen), "datalen in limits");
 480   return relocInfo(relocInfo::data_prefix_tag, relocInfo::RAW_BITS, relocInfo::datalen_tag | datalen);
 481 }
 482 
 483 
 484 // Holder for flyweight relocation objects.
 485 // Although the flyweight subclasses are of varying sizes,
 486 // the holder is "one size fits all".
 487 class RelocationHolder VALUE_OBJ_CLASS_SPEC {
 488   friend class Relocation;
 489   friend class CodeSection;
 490 
 491  private:
 492   // this preallocated memory must accommodate all subclasses of Relocation
 493   // (this number is assertion-checked in Relocation::operator new)
 494   enum { _relocbuf_size = 5 };
 495   void* _relocbuf[ _relocbuf_size ];
 496 
 497  public:
 498   Relocation* reloc() const { return (Relocation*) &_relocbuf[0]; }
 499   inline relocInfo::relocType type() const;
 500 
 501   // Add a constant offset to a relocation.  Helper for class Address.
 502   RelocationHolder plus(int offset) const;
 503 
 504   inline RelocationHolder();                // initializes type to none
 505 
 506   inline RelocationHolder(Relocation* r);   // make a copy
 507 
 508   static const RelocationHolder none;
 509 };
 510 
 511 // A RelocIterator iterates through the relocation information of a CodeBlob.
 512 // It is a variable BoundRelocation which is able to take on successive
 513 // values as it is advanced through a code stream.
 514 // Usage:
 515 //   RelocIterator iter(nm);
 516 //   while (iter.next()) {
 517 //     iter.reloc()->some_operation();
 518 //   }
 519 // or:
 520 //   RelocIterator iter(nm);
 521 //   while (iter.next()) {
 522 //     switch (iter.type()) {
 523 //      case relocInfo::oop_type          :
 524 //      case relocInfo::ic_type           :
 525 //      case relocInfo::prim_type         :
 526 //      case relocInfo::uncommon_type     :
 527 //      case relocInfo::runtime_call_type :
 528 //      case relocInfo::internal_word_type:
 529 //      case relocInfo::external_word_type:
 530 //      ...
 531 //     }
 532 //   }
 533 
 534 class RelocIterator : public StackObj {
 535   enum { SECT_LIMIT = 3 };  // must be equal to CodeBuffer::SECT_LIMIT, checked in ctor
 536   friend class Relocation;
 537   friend class relocInfo;       // for change_reloc_info_for_address only
 538   typedef relocInfo::relocType relocType;
 539 
 540  private:
 541   address         _limit;   // stop producing relocations after this _addr
 542   relocInfo*      _current; // the current relocation information
 543   relocInfo*      _end;     // end marker; we're done iterating when _current == _end
 544   CompiledMethod* _code;    // compiled method containing _addr
 545   address         _addr;    // instruction to which the relocation applies
 546   short           _databuf; // spare buffer for compressed data
 547   short*          _data;    // pointer to the relocation's data
 548   short           _datalen; // number of halfwords in _data
 549   char            _format;  // position within the instruction
 550 
 551   // Base addresses needed to compute targets of section_word_type relocs.
 552   address _section_start[SECT_LIMIT];
 553   address _section_end  [SECT_LIMIT];
 554 
 555   void set_has_current(bool b) {
 556     _datalen = !b ? -1 : 0;
 557     debug_only(_data = NULL);
 558   }
 559   void set_current(relocInfo& ri) {
 560     _current = &ri;
 561     set_has_current(true);
 562   }
 563 
 564   RelocationHolder _rh; // where the current relocation is allocated
 565 
 566   relocInfo* current() const { assert(has_current(), "must have current");
 567                                return _current; }
 568 
 569   void set_limits(address begin, address limit);
 570 
 571   void advance_over_prefix();    // helper method
 572 
 573   void initialize_misc();
 574 
 575   void initialize(CompiledMethod* nm, address begin, address limit);
 576 
 577   RelocIterator() { initialize_misc(); }
 578 
 579  public:
 580   // constructor
 581   RelocIterator(CompiledMethod* nm, address begin = NULL, address limit = NULL);
 582   RelocIterator(CodeSection* cb, address begin = NULL, address limit = NULL);
 583 
 584   // get next reloc info, return !eos
 585   bool next() {
 586     _current++;
 587     assert(_current <= _end, "must not overrun relocInfo");
 588     if (_current == _end) {
 589       set_has_current(false);
 590       return false;
 591     }
 592     set_has_current(true);
 593 
 594     if (_current->is_prefix()) {
 595       advance_over_prefix();
 596       assert(!current()->is_prefix(), "only one prefix at a time");
 597     }
 598 
 599     _addr += _current->addr_offset();
 600 
 601     if (_limit != NULL && _addr >= _limit) {
 602       set_has_current(false);
 603       return false;
 604     }
 605 
 606     if (relocInfo::have_format)  _format = current()->format();
 607     return true;
 608   }
 609 
 610   // accessors
 611   address      limit()        const { return _limit; }
 612   void     set_limit(address x);
 613   relocType    type()         const { return current()->type(); }
 614   int          format()       const { return (relocInfo::have_format) ? current()->format() : 0; }
 615   address      addr()         const { return _addr; }
 616   CompiledMethod*     code()  const { return _code; }
 617   nmethod*     code_as_nmethod() const;
 618   short*       data()         const { return _data; }
 619   int          datalen()      const { return _datalen; }
 620   bool     has_current()      const { return _datalen >= 0; }
 621 
 622   void       set_addr(address addr) { _addr = addr; }
 623   bool   addr_in_const()      const;
 624 
 625   address section_start(int n) const {
 626     assert(_section_start[n], "must be initialized");
 627     return _section_start[n];
 628   }
 629   address section_end(int n) const {
 630     assert(_section_end[n], "must be initialized");
 631     return _section_end[n];
 632   }
 633 
 634   // The address points to the affected displacement part of the instruction.
 635   // For RISC, this is just the whole instruction.
 636   // For Intel, this is an unaligned 32-bit word.
 637 
 638   // type-specific relocation accessors:  oop_Relocation* oop_reloc(), etc.
 639   #define EACH_TYPE(name)                               \
 640   inline name##_Relocation* name##_reloc();
 641   APPLY_TO_RELOCATIONS(EACH_TYPE)
 642   #undef EACH_TYPE
 643   // generic relocation accessor; switches on type to call the above
 644   Relocation* reloc();
 645 
 646   // CodeBlob's have relocation indexes for faster random access:
 647   static int locs_and_index_size(int code_size, int locs_size);
 648   // Store an index into [dest_start+dest_count..dest_end).
 649   // At dest_start[0..dest_count] is the actual relocation information.
 650   // Everything else up to dest_end is free space for the index.
 651   static void create_index(relocInfo* dest_begin, int dest_count, relocInfo* dest_end);
 652 
 653 #ifndef PRODUCT
 654  public:
 655   void print();
 656   void print_current();
 657 #endif
 658 };
 659 
 660 
 661 // A Relocation is a flyweight object allocated within a RelocationHolder.
 662 // It represents the relocation data of relocation record.
 663 // So, the RelocIterator unpacks relocInfos into Relocations.
 664 
 665 class Relocation VALUE_OBJ_CLASS_SPEC {
 666   friend class RelocationHolder;
 667   friend class RelocIterator;
 668 
 669  private:
 670   static void guarantee_size();
 671 
 672   // When a relocation has been created by a RelocIterator,
 673   // this field is non-null.  It allows the relocation to know
 674   // its context, such as the address to which it applies.
 675   RelocIterator* _binding;
 676 
 677  protected:
 678   RelocIterator* binding() const {
 679     assert(_binding != NULL, "must be bound");
 680     return _binding;
 681   }
 682   void set_binding(RelocIterator* b) {
 683     assert(_binding == NULL, "must be unbound");
 684     _binding = b;
 685     assert(_binding != NULL, "must now be bound");
 686   }
 687 
 688   Relocation() {
 689     _binding = NULL;
 690   }
 691 
 692   static RelocationHolder newHolder() {
 693     return RelocationHolder();
 694   }
 695 
 696  public:
 697   void* operator new(size_t size, const RelocationHolder& holder) throw() {
 698     if (size > sizeof(holder._relocbuf)) guarantee_size();
 699     assert((void* const *)holder.reloc() == &holder._relocbuf[0], "ptrs must agree");
 700     return holder.reloc();
 701   }
 702 
 703   // make a generic relocation for a given type (if possible)
 704   static RelocationHolder spec_simple(relocInfo::relocType rtype);
 705 
 706   // here is the type-specific hook which writes relocation data:
 707   virtual void pack_data_to(CodeSection* dest) { }
 708 
 709   // here is the type-specific hook which reads (unpacks) relocation data:
 710   virtual void unpack_data() {
 711     assert(datalen()==0 || type()==relocInfo::none, "no data here");
 712   }
 713 
 714  protected:
 715   // Helper functions for pack_data_to() and unpack_data().
 716 
 717   // Most of the compression logic is confined here.
 718   // (The "immediate data" mechanism of relocInfo works independently
 719   // of this stuff, and acts to further compress most 1-word data prefixes.)
 720 
 721   // A variable-width int is encoded as a short if it will fit in 16 bits.
 722   // The decoder looks at datalen to decide whether to unpack short or jint.
 723   // Most relocation records are quite simple, containing at most two ints.
 724 
 725   static bool is_short(jint x) { return x == (short)x; }
 726   static short* add_short(short* p, int x)  { *p++ = x; return p; }
 727   static short* add_jint (short* p, jint x) {
 728     *p++ = relocInfo::data0_from_int(x); *p++ = relocInfo::data1_from_int(x);
 729     return p;
 730   }
 731   static short* add_var_int(short* p, jint x) {   // add a variable-width int
 732     if (is_short(x))  p = add_short(p, x);
 733     else              p = add_jint (p, x);
 734     return p;
 735   }
 736 
 737   static short* pack_1_int_to(short* p, jint x0) {
 738     // Format is one of:  [] [x] [Xx]
 739     if (x0 != 0)  p = add_var_int(p, x0);
 740     return p;
 741   }
 742   int unpack_1_int() {
 743     assert(datalen() <= 2, "too much data");
 744     return relocInfo::jint_data_at(0, data(), datalen());
 745   }
 746 
 747   // With two ints, the short form is used only if both ints are short.
 748   short* pack_2_ints_to(short* p, jint x0, jint x1) {
 749     // Format is one of:  [] [x y?] [Xx Y?y]
 750     if (x0 == 0 && x1 == 0) {
 751       // no halfwords needed to store zeroes
 752     } else if (is_short(x0) && is_short(x1)) {
 753       // 1-2 halfwords needed to store shorts
 754       p = add_short(p, x0); if (x1!=0) p = add_short(p, x1);
 755     } else {
 756       // 3-4 halfwords needed to store jints
 757       p = add_jint(p, x0);             p = add_var_int(p, x1);
 758     }
 759     return p;
 760   }
 761   void unpack_2_ints(jint& x0, jint& x1) {
 762     int    dlen = datalen();
 763     short* dp  = data();
 764     if (dlen <= 2) {
 765       x0 = relocInfo::short_data_at(0, dp, dlen);
 766       x1 = relocInfo::short_data_at(1, dp, dlen);
 767     } else {
 768       assert(dlen <= 4, "too much data");
 769       x0 = relocInfo::jint_data_at(0, dp, dlen);
 770       x1 = relocInfo::jint_data_at(2, dp, dlen);
 771     }
 772   }
 773 
 774  protected:
 775   // platform-independent utility for patching constant section
 776   void       const_set_data_value    (address x);
 777   void       const_verify_data_value (address x);
 778   // platform-dependent utilities for decoding and patching instructions
 779   void       pd_set_data_value       (address x, intptr_t off, bool verify_only = false); // a set or mem-ref
 780   void       pd_verify_data_value    (address x, intptr_t off) { pd_set_data_value(x, off, true); }
 781   address    pd_call_destination     (address orig_addr = NULL);
 782   void       pd_set_call_destination (address x);
 783 
 784   // this extracts the address of an address in the code stream instead of the reloc data
 785   address* pd_address_in_code       ();
 786 
 787   // this extracts an address from the code stream instead of the reloc data
 788   address  pd_get_address_from_code ();
 789 
 790   // these convert from byte offsets, to scaled offsets, to addresses
 791   static jint scaled_offset(address x, address base) {
 792     int byte_offset = x - base;
 793     int offset = -byte_offset / relocInfo::addr_unit();
 794     assert(address_from_scaled_offset(offset, base) == x, "just checkin'");
 795     return offset;
 796   }
 797   static jint scaled_offset_null_special(address x, address base) {
 798     // Some relocations treat offset=0 as meaning NULL.
 799     // Handle this extra convention carefully.
 800     if (x == NULL)  return 0;
 801     assert(x != base, "offset must not be zero");
 802     return scaled_offset(x, base);
 803   }
 804   static address address_from_scaled_offset(jint offset, address base) {
 805     int byte_offset = -( offset * relocInfo::addr_unit() );
 806     return base + byte_offset;
 807   }
 808 
 809   // helpers for mapping between old and new addresses after a move or resize
 810   address old_addr_for(address newa, const CodeBuffer* src, CodeBuffer* dest);
 811   address new_addr_for(address olda, const CodeBuffer* src, CodeBuffer* dest);
 812   void normalize_address(address& addr, const CodeSection* dest, bool allow_other_sections = false);
 813 
 814  public:
 815   // accessors which only make sense for a bound Relocation
 816   address         addr()            const { return binding()->addr(); }
 817   CompiledMethod* code()            const { return binding()->code(); }
 818   nmethod*        code_as_nmethod() const { return binding()->code_as_nmethod(); }
 819   bool            addr_in_const()   const { return binding()->addr_in_const(); }
 820  protected:
 821   short*   data()         const { return binding()->data(); }
 822   int      datalen()      const { return binding()->datalen(); }
 823   int      format()       const { return binding()->format(); }
 824 
 825  public:
 826   virtual relocInfo::relocType type()            { return relocInfo::none; }
 827 
 828   // is it a call instruction?
 829   virtual bool is_call()                         { return false; }
 830 
 831   // is it a data movement instruction?
 832   virtual bool is_data()                         { return false; }
 833 
 834   // some relocations can compute their own values
 835   virtual address  value();
 836 
 837   // all relocations are able to reassert their values
 838   virtual void set_value(address x);
 839 
 840   virtual void clear_inline_cache()              { }
 841 
 842   // This method assumes that all virtual/static (inline) caches are cleared (since for static_call_type and
 843   // ic_call_type is not always posisition dependent (depending on the state of the cache)). However, this is
 844   // probably a reasonable assumption, since empty caches simplifies code reloacation.
 845   virtual void fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest) { }
 846 
 847   void print();
 848 };
 849 
 850 
 851 // certain inlines must be deferred until class Relocation is defined:
 852 
 853 inline RelocationHolder::RelocationHolder() {
 854   // initialize the vtbl, just to keep things type-safe
 855   new(*this) Relocation();
 856 }
 857 
 858 
 859 inline RelocationHolder::RelocationHolder(Relocation* r) {
 860   // wordwise copy from r (ok if it copies garbage after r)
 861   for (int i = 0; i < _relocbuf_size; i++) {
 862     _relocbuf[i] = ((void**)r)[i];
 863   }
 864 }
 865 
 866 
 867 relocInfo::relocType RelocationHolder::type() const {
 868   return reloc()->type();
 869 }
 870 
 871 // A DataRelocation always points at a memory or load-constant instruction..
 872 // It is absolute on most machines, and the constant is split on RISCs.
 873 // The specific subtypes are oop, external_word, and internal_word.
 874 // By convention, the "value" does not include a separately reckoned "offset".
 875 class DataRelocation : public Relocation {
 876  public:
 877   bool          is_data()                      { return true; }
 878 
 879   // both target and offset must be computed somehow from relocation data
 880   virtual int    offset()                      { return 0; }
 881   address         value()                      = 0;
 882   void        set_value(address x)             { set_value(x, offset()); }
 883   void        set_value(address x, intptr_t o) {
 884     if (addr_in_const())
 885       const_set_data_value(x);
 886     else
 887       pd_set_data_value(x, o);
 888   }
 889   void        verify_value(address x) {
 890     if (addr_in_const())
 891       const_verify_data_value(x);
 892     else
 893       pd_verify_data_value(x, offset());
 894   }
 895 
 896   // The "o" (displacement) argument is relevant only to split relocations
 897   // on RISC machines.  In some CPUs (SPARC), the set-hi and set-lo ins'ns
 898   // can encode more than 32 bits between them.  This allows compilers to
 899   // share set-hi instructions between addresses that differ by a small
 900   // offset (e.g., different static variables in the same class).
 901   // On such machines, the "x" argument to set_value on all set-lo
 902   // instructions must be the same as the "x" argument for the
 903   // corresponding set-hi instructions.  The "o" arguments for the
 904   // set-hi instructions are ignored, and must not affect the high-half
 905   // immediate constant.  The "o" arguments for the set-lo instructions are
 906   // added into the low-half immediate constant, and must not overflow it.
 907 };
 908 
 909 // A CallRelocation always points at a call instruction.
 910 // It is PC-relative on most machines.
 911 class CallRelocation : public Relocation {
 912  public:
 913   bool is_call() { return true; }
 914 
 915   address  destination()                    { return pd_call_destination(); }
 916   void     set_destination(address x); // pd_set_call_destination
 917 
 918   void     fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest);
 919   address  value()                          { return destination();  }
 920   void     set_value(address x)             { set_destination(x); }
 921 };
 922 
 923 class oop_Relocation : public DataRelocation {
 924   relocInfo::relocType type() { return relocInfo::oop_type; }
 925 
 926  public:
 927   // encode in one of these formats:  [] [n] [n l] [Nn l] [Nn Ll]
 928   // an oop in the CodeBlob's oop pool
 929   static RelocationHolder spec(int oop_index, int offset = 0) {
 930     assert(oop_index > 0, "must be a pool-resident oop");
 931     RelocationHolder rh = newHolder();
 932     new(rh) oop_Relocation(oop_index, offset);
 933     return rh;
 934   }
 935   // an oop in the instruction stream
 936   static RelocationHolder spec_for_immediate() {
 937     const int oop_index = 0;
 938     const int offset    = 0;    // if you want an offset, use the oop pool
 939     RelocationHolder rh = newHolder();
 940     new(rh) oop_Relocation(oop_index, offset);
 941     return rh;
 942   }
 943 
 944  private:
 945   jint _oop_index;                  // if > 0, index into CodeBlob::oop_at
 946   jint _offset;                     // byte offset to apply to the oop itself
 947 
 948   oop_Relocation(int oop_index, int offset) {
 949     _oop_index = oop_index; _offset = offset;
 950   }
 951 
 952   friend class RelocIterator;
 953   oop_Relocation() { }
 954 
 955  public:
 956   int oop_index() { return _oop_index; }
 957   int offset()    { return _offset; }
 958 
 959   // data is packed in "2_ints" format:  [i o] or [Ii Oo]
 960   void pack_data_to(CodeSection* dest);
 961   void unpack_data();
 962 
 963   void fix_oop_relocation();        // reasserts oop value
 964 
 965   void verify_oop_relocation();
 966 
 967   address value()  { return (address) *oop_addr(); }
 968 
 969   bool oop_is_immediate()  { return oop_index() == 0; }
 970 
 971   oop* oop_addr();                  // addr or &pool[jint_data]
 972   oop  oop_value();                 // *oop_addr
 973   // Note:  oop_value transparently converts Universe::non_oop_word to NULL.
 974 };
 975 
 976 
 977 // copy of oop_Relocation for now but may delete stuff in both/either
 978 class metadata_Relocation : public DataRelocation {
 979   relocInfo::relocType type() { return relocInfo::metadata_type; }
 980 
 981  public:
 982   // encode in one of these formats:  [] [n] [n l] [Nn l] [Nn Ll]
 983   // an metadata in the CodeBlob's metadata pool
 984   static RelocationHolder spec(int metadata_index, int offset = 0) {
 985     assert(metadata_index > 0, "must be a pool-resident metadata");
 986     RelocationHolder rh = newHolder();
 987     new(rh) metadata_Relocation(metadata_index, offset);
 988     return rh;
 989   }
 990   // an metadata in the instruction stream
 991   static RelocationHolder spec_for_immediate() {
 992     const int metadata_index = 0;
 993     const int offset    = 0;    // if you want an offset, use the metadata pool
 994     RelocationHolder rh = newHolder();
 995     new(rh) metadata_Relocation(metadata_index, offset);
 996     return rh;
 997   }
 998 
 999  private:
1000   jint _metadata_index;            // if > 0, index into nmethod::metadata_at
1001   jint _offset;                     // byte offset to apply to the metadata itself
1002 
1003   metadata_Relocation(int metadata_index, int offset) {
1004     _metadata_index = metadata_index; _offset = offset;
1005   }
1006 
1007   friend class RelocIterator;
1008   metadata_Relocation() { }
1009 
1010   // Fixes a Metadata pointer in the code. Most platforms embeds the
1011   // Metadata pointer in the code at compile time so this is empty
1012   // for them.
1013   void pd_fix_value(address x);
1014 
1015  public:
1016   int metadata_index() { return _metadata_index; }
1017   int offset()    { return _offset; }
1018 
1019   // data is packed in "2_ints" format:  [i o] or [Ii Oo]
1020   void pack_data_to(CodeSection* dest);
1021   void unpack_data();
1022 
1023   void fix_metadata_relocation();        // reasserts metadata value
1024 
1025   void verify_metadata_relocation();
1026 
1027   address value()  { return (address) *metadata_addr(); }
1028 
1029   bool metadata_is_immediate()  { return metadata_index() == 0; }
1030 
1031   Metadata**   metadata_addr();                  // addr or &pool[jint_data]
1032   Metadata*    metadata_value();                 // *metadata_addr
1033   // Note:  metadata_value transparently converts Universe::non_metadata_word to NULL.
1034 };
1035 
1036 
1037 class virtual_call_Relocation : public CallRelocation {
1038   relocInfo::relocType type() { return relocInfo::virtual_call_type; }
1039 
1040  public:
1041   // "cached_value" points to the first associated set-oop.
1042   // The oop_limit helps find the last associated set-oop.
1043   // (See comments at the top of this file.)
1044   static RelocationHolder spec(address cached_value, jint method_index = 0) {
1045     RelocationHolder rh = newHolder();
1046     new(rh) virtual_call_Relocation(cached_value, method_index);
1047     return rh;
1048   }
1049 
1050  private:
1051   address _cached_value; // location of set-value instruction
1052   jint    _method_index; // resolved method for a Java call
1053 
1054   virtual_call_Relocation(address cached_value, int method_index) {
1055     _cached_value = cached_value;
1056     _method_index = method_index;
1057     assert(cached_value != NULL, "first oop address must be specified");
1058   }
1059 
1060   friend class RelocIterator;
1061   virtual_call_Relocation() { }
1062 
1063  public:
1064   address cached_value();
1065 
1066   int     method_index() { return _method_index; }
1067   Method* method_value();
1068 
1069   // data is packed as scaled offsets in "2_ints" format:  [f l] or [Ff Ll]
1070   // oop_limit is set to 0 if the limit falls somewhere within the call.
1071   // When unpacking, a zero oop_limit is taken to refer to the end of the call.
1072   // (This has the effect of bringing in the call's delay slot on SPARC.)
1073   void pack_data_to(CodeSection* dest);
1074   void unpack_data();
1075 
1076   void clear_inline_cache();
1077 };
1078 
1079 
1080 class opt_virtual_call_Relocation : public CallRelocation {
1081   relocInfo::relocType type() { return relocInfo::opt_virtual_call_type; }
1082 
1083  public:
1084   static RelocationHolder spec(int method_index = 0) {
1085     RelocationHolder rh = newHolder();
1086     new(rh) opt_virtual_call_Relocation(method_index);
1087     return rh;
1088   }
1089 
1090  private:
1091   jint _method_index; // resolved method for a Java call
1092 
1093   opt_virtual_call_Relocation(int method_index) {
1094     _method_index = method_index;
1095   }
1096 
1097   friend class RelocIterator;
1098   opt_virtual_call_Relocation() {}
1099 
1100  public:
1101   int     method_index() { return _method_index; }
1102   Method* method_value();
1103 
1104   void pack_data_to(CodeSection* dest);
1105   void unpack_data();
1106 
1107   void clear_inline_cache();
1108 
1109   // find the matching static_stub
1110   address static_stub();
1111 };
1112 
1113 
1114 class static_call_Relocation : public CallRelocation {
1115   relocInfo::relocType type() { return relocInfo::static_call_type; }
1116 
1117  public:
1118   static RelocationHolder spec(int method_index = 0) {
1119     RelocationHolder rh = newHolder();
1120     new(rh) static_call_Relocation(method_index);
1121     return rh;
1122   }
1123 
1124  private:
1125   jint _method_index; // resolved method for a Java call
1126 
1127   static_call_Relocation(int method_index) {
1128     _method_index = method_index;
1129   }
1130 
1131   friend class RelocIterator;
1132   static_call_Relocation() {}
1133 
1134  public:
1135   int     method_index() { return _method_index; }
1136   Method* method_value();
1137 
1138   void pack_data_to(CodeSection* dest);
1139   void unpack_data();
1140 
1141   void clear_inline_cache();
1142 
1143   // find the matching static_stub
1144   address static_stub();
1145 };
1146 
1147 class static_stub_Relocation : public Relocation {
1148   relocInfo::relocType type() { return relocInfo::static_stub_type; }
1149 
1150  public:
1151   static RelocationHolder spec(address static_call) {
1152     RelocationHolder rh = newHolder();
1153     new(rh) static_stub_Relocation(static_call);
1154     return rh;
1155   }
1156 
1157  private:
1158   address _static_call;  // location of corresponding static_call
1159 
1160   static_stub_Relocation(address static_call) {
1161     _static_call = static_call;
1162   }
1163 
1164   friend class RelocIterator;
1165   static_stub_Relocation() { }
1166 
1167  public:
1168   void clear_inline_cache();
1169 
1170   address static_call() { return _static_call; }
1171 
1172   // data is packed as a scaled offset in "1_int" format:  [c] or [Cc]
1173   void pack_data_to(CodeSection* dest);
1174   void unpack_data();
1175 };
1176 
1177 class runtime_call_Relocation : public CallRelocation {
1178   relocInfo::relocType type() { return relocInfo::runtime_call_type; }
1179 
1180  public:
1181   static RelocationHolder spec() {
1182     RelocationHolder rh = newHolder();
1183     new(rh) runtime_call_Relocation();
1184     return rh;
1185   }
1186 
1187  private:
1188   friend class RelocIterator;
1189   runtime_call_Relocation() { }
1190 
1191  public:
1192 };
1193 
1194 // Trampoline Relocations.
1195 // A trampoline allows to encode a small branch in the code, even if there
1196 // is the chance that this branch can not reach all possible code locations.
1197 // If the relocation finds that a branch is too far for the instruction
1198 // in the code, it can patch it to jump to the trampoline where is
1199 // sufficient space for a far branch. Needed on PPC.
1200 class trampoline_stub_Relocation : public Relocation {
1201   relocInfo::relocType type() { return relocInfo::trampoline_stub_type; }
1202 
1203  public:
1204   static RelocationHolder spec(address static_call) {
1205     RelocationHolder rh = newHolder();
1206     return (new (rh) trampoline_stub_Relocation(static_call));
1207   }
1208 
1209  private:
1210   address _owner;    // Address of the NativeCall that owns the trampoline.
1211 
1212   trampoline_stub_Relocation(address owner) {
1213     _owner = owner;
1214   }
1215 
1216   friend class RelocIterator;
1217   trampoline_stub_Relocation() { }
1218 
1219  public:
1220 
1221   // Return the address of the NativeCall that owns the trampoline.
1222   address owner() { return _owner; }
1223 
1224   void pack_data_to(CodeSection * dest);
1225   void unpack_data();
1226 
1227   // Find the trampoline stub for a call.
1228   static address get_trampoline_for(address call, nmethod* code);
1229 };
1230 
1231 class external_word_Relocation : public DataRelocation {
1232   relocInfo::relocType type() { return relocInfo::external_word_type; }
1233 
1234  public:
1235   static RelocationHolder spec(address target) {
1236     assert(target != NULL, "must not be null");
1237     RelocationHolder rh = newHolder();
1238     new(rh) external_word_Relocation(target);
1239     return rh;
1240   }
1241 
1242   // Use this one where all 32/64 bits of the target live in the code stream.
1243   // The target must be an intptr_t, and must be absolute (not relative).
1244   static RelocationHolder spec_for_immediate() {
1245     RelocationHolder rh = newHolder();
1246     new(rh) external_word_Relocation(NULL);
1247     return rh;
1248   }
1249 
1250   // Some address looking values aren't safe to treat as relocations
1251   // and should just be treated as constants.
1252   static bool can_be_relocated(address target) {
1253     assert(target == NULL || (uintptr_t)target >= (uintptr_t)os::vm_page_size(), INTPTR_FORMAT, (intptr_t)target);
1254     return target != NULL;
1255   }
1256 
1257  private:
1258   address _target;                  // address in runtime
1259 
1260   external_word_Relocation(address target) {
1261     _target = target;
1262   }
1263 
1264   friend class RelocIterator;
1265   external_word_Relocation() { }
1266 
1267  public:
1268   // data is packed as a well-known address in "1_int" format:  [a] or [Aa]
1269   // The function runtime_address_to_index is used to turn full addresses
1270   // to short indexes, if they are pre-registered by the stub mechanism.
1271   // If the "a" value is 0 (i.e., _target is NULL), the address is stored
1272   // in the code stream.  See external_word_Relocation::target().
1273   void pack_data_to(CodeSection* dest);
1274   void unpack_data();
1275 
1276   void fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest);
1277   address  target();        // if _target==NULL, fetch addr from code stream
1278   address  value()          { return target(); }
1279 };
1280 
1281 class internal_word_Relocation : public DataRelocation {
1282   relocInfo::relocType type() { return relocInfo::internal_word_type; }
1283 
1284  public:
1285   static RelocationHolder spec(address target) {
1286     assert(target != NULL, "must not be null");
1287     RelocationHolder rh = newHolder();
1288     new(rh) internal_word_Relocation(target);
1289     return rh;
1290   }
1291 
1292   // use this one where all the bits of the target can fit in the code stream:
1293   static RelocationHolder spec_for_immediate() {
1294     RelocationHolder rh = newHolder();
1295     new(rh) internal_word_Relocation(NULL);
1296     return rh;
1297   }
1298 
1299   internal_word_Relocation(address target) {
1300     _target  = target;
1301     _section = -1;  // self-relative
1302   }
1303 
1304  protected:
1305   address _target;                  // address in CodeBlob
1306   int     _section;                 // section providing base address, if any
1307 
1308   friend class RelocIterator;
1309   internal_word_Relocation() { }
1310 
1311   // bit-width of LSB field in packed offset, if section >= 0
1312   enum { section_width = 2 }; // must equal CodeBuffer::sect_bits
1313 
1314  public:
1315   // data is packed as a scaled offset in "1_int" format:  [o] or [Oo]
1316   // If the "o" value is 0 (i.e., _target is NULL), the offset is stored
1317   // in the code stream.  See internal_word_Relocation::target().
1318   // If _section is not -1, it is appended to the low bits of the offset.
1319   void pack_data_to(CodeSection* dest);
1320   void unpack_data();
1321 
1322   void fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest);
1323   address  target();        // if _target==NULL, fetch addr from code stream
1324   int      section()        { return _section;   }
1325   address  value()          { return target();   }
1326 };
1327 
1328 class section_word_Relocation : public internal_word_Relocation {
1329   relocInfo::relocType type() { return relocInfo::section_word_type; }
1330 
1331  public:
1332   static RelocationHolder spec(address target, int section) {
1333     RelocationHolder rh = newHolder();
1334     new(rh) section_word_Relocation(target, section);
1335     return rh;
1336   }
1337 
1338   section_word_Relocation(address target, int section) {
1339     assert(target != NULL, "must not be null");
1340     assert(section >= 0, "must be a valid section");
1341     _target  = target;
1342     _section = section;
1343   }
1344 
1345   //void pack_data_to -- inherited
1346   void unpack_data();
1347 
1348  private:
1349   friend class RelocIterator;
1350   section_word_Relocation() { }
1351 };
1352 
1353 
1354 class poll_Relocation : public Relocation {
1355   bool          is_data()                      { return true; }
1356   relocInfo::relocType type() { return relocInfo::poll_type; }
1357   void     fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest);
1358 };
1359 
1360 class poll_return_Relocation : public poll_Relocation {
1361   relocInfo::relocType type() { return relocInfo::poll_return_type; }
1362 };
1363 
1364 // We know all the xxx_Relocation classes, so now we can define these:
1365 #define EACH_CASE(name)                                         \
1366 inline name##_Relocation* RelocIterator::name##_reloc() {       \
1367   assert(type() == relocInfo::name##_type, "type must agree");  \
1368   /* The purpose of the placed "new" is to re-use the same */   \
1369   /* stack storage for each new iteration. */                   \
1370   name##_Relocation* r = new(_rh) name##_Relocation();          \
1371   r->set_binding(this);                                         \
1372   r->name##_Relocation::unpack_data();                          \
1373   return r;                                                     \
1374 }
1375 APPLY_TO_RELOCATIONS(EACH_CASE);
1376 #undef EACH_CASE
1377 
1378 inline RelocIterator::RelocIterator(CompiledMethod* nm, address begin, address limit) {
1379   initialize(nm, begin, limit);
1380 }
1381 
1382 #endif // SHARE_VM_CODE_RELOCINFO_HPP
--- EOF ---