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