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--- old/src/share/vm/code/relocInfo.hpp
+++ new/src/share/vm/code/relocInfo.hpp
1 1 /*
2 2 * Copyright 1997-2008 Sun Microsystems, Inc. All Rights Reserved.
3 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 4 *
5 5 * This code is free software; you can redistribute it and/or modify it
6 6 * under the terms of the GNU General Public License version 2 only, as
7 7 * published by the Free Software Foundation.
8 8 *
9 9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 12 * version 2 for more details (a copy is included in the LICENSE file that
13 13 * accompanied this code).
14 14 *
15 15 * You should have received a copy of the GNU General Public License version
16 16 * 2 along with this work; if not, write to the Free Software Foundation,
17 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 18 *
19 19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 21 * have any questions.
22 22 *
23 23 */
24 24
25 25 // Types in this file:
26 26 // relocInfo
27 27 // One element of an array of halfwords encoding compressed relocations.
28 28 // Also, the source of relocation types (relocInfo::oop_type, ...).
29 29 // Relocation
30 30 // A flyweight object representing a single relocation.
31 31 // It is fully unpacked from the compressed relocation array.
32 32 // oop_Relocation, ... (subclasses of Relocation)
33 33 // The location of some type-specific operations (oop_addr, ...).
34 34 // Also, the source of relocation specs (oop_Relocation::spec, ...).
35 35 // RelocationHolder
36 36 // A ValueObj type which acts as a union holding a Relocation object.
37 37 // Represents a relocation spec passed into a CodeBuffer during assembly.
38 38 // RelocIterator
39 39 // A StackObj which iterates over the relocations associated with
40 40 // a range of code addresses. Can be used to operate a copy of code.
41 41 // PatchingRelocIterator
42 42 // Specialized subtype of RelocIterator which removes breakpoints
43 43 // temporarily during iteration, then restores them.
44 44 // BoundRelocation
45 45 // An _internal_ type shared by packers and unpackers of relocations.
46 46 // It pastes together a RelocationHolder with some pointers into
47 47 // code and relocInfo streams.
48 48
49 49
50 50 // Notes on relocType:
51 51 //
52 52 // These hold enough information to read or write a value embedded in
53 53 // the instructions of an CodeBlob. They're used to update:
54 54 //
55 55 // 1) embedded oops (isOop() == true)
56 56 // 2) inline caches (isIC() == true)
57 57 // 3) runtime calls (isRuntimeCall() == true)
58 58 // 4) internal word ref (isInternalWord() == true)
59 59 // 5) external word ref (isExternalWord() == true)
60 60 //
61 61 // when objects move (GC) or if code moves (compacting the code heap).
62 62 // They are also used to patch the code (if a call site must change)
63 63 //
64 64 // A relocInfo is represented in 16 bits:
65 65 // 4 bits indicating the relocation type
66 66 // 12 bits indicating the offset from the previous relocInfo address
67 67 //
68 68 // The offsets accumulate along the relocInfo stream to encode the
69 69 // address within the CodeBlob, which is named RelocIterator::addr().
70 70 // The address of a particular relocInfo always points to the first
71 71 // byte of the relevant instruction (and not to any of its subfields
72 72 // or embedded immediate constants).
73 73 //
74 74 // The offset value is scaled appropriately for the target machine.
75 75 // (See relocInfo_<arch>.hpp for the offset scaling.)
76 76 //
77 77 // On some machines, there may also be a "format" field which may provide
78 78 // additional information about the format of the instruction stream
79 79 // at the corresponding code address. The format value is usually zero.
80 80 // Any machine (such as Intel) whose instructions can sometimes contain
81 81 // more than one relocatable constant needs format codes to distinguish
82 82 // which operand goes with a given relocation.
83 83 //
84 84 // If the target machine needs N format bits, the offset has 12-N bits,
85 85 // the format is encoded between the offset and the type, and the
86 86 // relocInfo_<arch>.hpp file has manifest constants for the format codes.
87 87 //
88 88 // If the type is "data_prefix_tag" then the offset bits are further encoded,
89 89 // and in fact represent not a code-stream offset but some inline data.
90 90 // The data takes the form of a counted sequence of halfwords, which
91 91 // precedes the actual relocation record. (Clients never see it directly.)
92 92 // The interpetation of this extra data depends on the relocation type.
93 93 //
94 94 // On machines that have 32-bit immediate fields, there is usually
95 95 // little need for relocation "prefix" data, because the instruction stream
96 96 // is a perfectly reasonable place to store the value. On machines in
97 97 // which 32-bit values must be "split" across instructions, the relocation
98 98 // data is the "true" specification of the value, which is then applied
99 99 // to some field of the instruction (22 or 13 bits, on SPARC).
100 100 //
101 101 // Whenever the location of the CodeBlob changes, any PC-relative
102 102 // relocations, and any internal_word_type relocations, must be reapplied.
103 103 // After the GC runs, oop_type relocations must be reapplied.
104 104 //
105 105 //
106 106 // Here are meanings of the types:
107 107 //
108 108 // relocInfo::none -- a filler record
109 109 // Value: none
110 110 // Instruction: The corresponding code address is ignored
111 111 // Data: Any data prefix and format code are ignored
112 112 // (This means that any relocInfo can be disabled by setting
113 113 // its type to none. See relocInfo::remove.)
114 114 //
115 115 // relocInfo::oop_type -- a reference to an oop
116 116 // Value: an oop, or else the address (handle) of an oop
117 117 // Instruction types: memory (load), set (load address)
118 118 // Data: [] an oop stored in 4 bytes of instruction
119 119 // [n] n is the index of an oop in the CodeBlob's oop pool
120 120 // [[N]n l] and l is a byte offset to be applied to the oop
121 121 // [Nn Ll] both index and offset may be 32 bits if necessary
122 122 // Here is a special hack, used only by the old compiler:
123 123 // [[N]n 00] the value is the __address__ of the nth oop in the pool
124 124 // (Note that the offset allows optimal references to class variables.)
125 125 //
126 126 // relocInfo::internal_word_type -- an address within the same CodeBlob
127 127 // relocInfo::section_word_type -- same, but can refer to another section
128 128 // Value: an address in the CodeBlob's code or constants section
129 129 // Instruction types: memory (load), set (load address)
130 130 // Data: [] stored in 4 bytes of instruction
131 131 // [[L]l] a relative offset (see [About Offsets] below)
132 132 // In the case of section_word_type, the offset is relative to a section
133 133 // base address, and the section number (e.g., SECT_INSTS) is encoded
134 134 // into the low two bits of the offset L.
135 135 //
136 136 // relocInfo::external_word_type -- a fixed address in the runtime system
137 137 // Value: an address
138 138 // Instruction types: memory (load), set (load address)
139 139 // Data: [] stored in 4 bytes of instruction
140 140 // [n] the index of a "well-known" stub (usual case on RISC)
141 141 // [Ll] a 32-bit address
142 142 //
143 143 // relocInfo::runtime_call_type -- a fixed subroutine in the runtime system
144 144 // Value: an address
145 145 // Instruction types: PC-relative call (or a PC-relative branch)
146 146 // Data: [] stored in 4 bytes of instruction
147 147 //
148 148 // relocInfo::static_call_type -- a static call
149 149 // Value: an CodeBlob, a stub, or a fixup routine
150 150 // Instruction types: a call
151 151 // Data: []
152 152 // The identity of the callee is extracted from debugging information.
153 153 // //%note reloc_3
154 154 //
155 155 // relocInfo::virtual_call_type -- a virtual call site (which includes an inline
156 156 // cache)
157 157 // Value: an CodeBlob, a stub, the interpreter, or a fixup routine
158 158 // Instruction types: a call, plus some associated set-oop instructions
159 159 // Data: [] the associated set-oops are adjacent to the call
160 160 // [n] n is a relative offset to the first set-oop
161 161 // [[N]n l] and l is a limit within which the set-oops occur
162 162 // [Nn Ll] both n and l may be 32 bits if necessary
163 163 // The identity of the callee is extracted from debugging information.
164 164 //
165 165 // relocInfo::opt_virtual_call_type -- a virtual call site that is statically bound
166 166 //
167 167 // Same info as a static_call_type. We use a special type, so the handling of
168 168 // virtuals and statics are separated.
169 169 //
170 170 //
171 171 // The offset n points to the first set-oop. (See [About Offsets] below.)
172 172 // In turn, the set-oop instruction specifies or contains an oop cell devoted
173 173 // exclusively to the IC call, which can be patched along with the call.
174 174 //
175 175 // The locations of any other set-oops are found by searching the relocation
176 176 // information starting at the first set-oop, and continuing until all
177 177 // relocations up through l have been inspected. The value l is another
178 178 // relative offset. (Both n and l are relative to the call's first byte.)
179 179 //
180 180 // The limit l of the search is exclusive. However, if it points within
181 181 // the call (e.g., offset zero), it is adjusted to point after the call and
182 182 // any associated machine-specific delay slot.
183 183 //
184 184 // Since the offsets could be as wide as 32-bits, these conventions
185 185 // put no restrictions whatever upon code reorganization.
186 186 //
187 187 // The compiler is responsible for ensuring that transition from a clean
188 188 // state to a monomorphic compiled state is MP-safe. This implies that
189 189 // the system must respond well to intermediate states where a random
190 190 // subset of the set-oops has been correctly from the clean state
191 191 // upon entry to the VEP of the compiled method. In the case of a
192 192 // machine (Intel) with a single set-oop instruction, the 32-bit
193 193 // immediate field must not straddle a unit of memory coherence.
194 194 // //%note reloc_3
195 195 //
196 196 // relocInfo::breakpoint_type -- a conditional breakpoint in the code
197 197 // Value: none
198 198 // Instruction types: any whatsoever
199 199 // Data: [b [T]t i...]
200 200 // The b is a bit-packed word representing the breakpoint's attributes.
201 201 // The t is a target address which the breakpoint calls (when it is enabled).
202 202 // The i... is a place to store one or two instruction words overwritten
203 203 // by a trap, so that the breakpoint may be subsequently removed.
204 204 //
205 205 // relocInfo::static_stub_type -- an extra stub for each static_call_type
206 206 // Value: none
207 207 // Instruction types: a virtual call: { set_oop; jump; }
208 208 // Data: [[N]n] the offset of the associated static_call reloc
209 209 // This stub becomes the target of a static call which must be upgraded
210 210 // to a virtual call (because the callee is interpreted).
211 211 // See [About Offsets] below.
212 212 // //%note reloc_2
213 213 //
214 214 // For example:
215 215 //
216 216 // INSTRUCTIONS RELOC: TYPE PREFIX DATA
217 217 // ------------ ---- -----------
218 218 // sethi %hi(myObject), R oop_type [n(myObject)]
219 219 // ld [R+%lo(myObject)+fldOffset], R2 oop_type [n(myObject) fldOffset]
220 220 // add R2, 1, R2
221 221 // st R2, [R+%lo(myObject)+fldOffset] oop_type [n(myObject) fldOffset]
222 222 //%note reloc_1
223 223 //
224 224 // This uses 4 instruction words, 8 relocation halfwords,
225 225 // and an entry (which is sharable) in the CodeBlob's oop pool,
226 226 // for a total of 36 bytes.
227 227 //
228 228 // Note that the compiler is responsible for ensuring the "fldOffset" when
229 229 // added to "%lo(myObject)" does not overflow the immediate fields of the
230 230 // memory instructions.
231 231 //
232 232 //
233 233 // [About Offsets] Relative offsets are supplied to this module as
234 234 // positive byte offsets, but they may be internally stored scaled
235 235 // and/or negated, depending on what is most compact for the target
236 236 // system. Since the object pointed to by the offset typically
237 237 // precedes the relocation address, it is profitable to store
238 238 // these negative offsets as positive numbers, but this decision
239 239 // is internal to the relocation information abstractions.
240 240 //
241 241
242 242 class Relocation;
243 243 class CodeBuffer;
244 244 class CodeSection;
245 245 class RelocIterator;
246 246
247 247 class relocInfo VALUE_OBJ_CLASS_SPEC {
248 248 friend class RelocIterator;
249 249 public:
250 250 enum relocType {
251 251 none = 0, // Used when no relocation should be generated
252 252 oop_type = 1, // embedded oop
253 253 virtual_call_type = 2, // a standard inline cache call for a virtual send
254 254 opt_virtual_call_type = 3, // a virtual call that has been statically bound (i.e., no IC cache)
255 255 static_call_type = 4, // a static send
256 256 static_stub_type = 5, // stub-entry for static send (takes care of interpreter case)
257 257 runtime_call_type = 6, // call to fixed external routine
258 258 external_word_type = 7, // reference to fixed external address
259 259 internal_word_type = 8, // reference within the current code blob
260 260 section_word_type = 9, // internal, but a cross-section reference
261 261 poll_type = 10, // polling instruction for safepoints
262 262 poll_return_type = 11, // polling instruction for safepoints at return
263 263 breakpoint_type = 12, // an initialization barrier or safepoint
264 264 yet_unused_type = 13, // Still unused
265 265 yet_unused_type_2 = 14, // Still unused
266 266 data_prefix_tag = 15, // tag for a prefix (carries data arguments)
267 267 type_mask = 15 // A mask which selects only the above values
268 268 };
269 269
270 270 protected:
271 271 unsigned short _value;
272 272
273 273 enum RawBitsToken { RAW_BITS };
274 274 relocInfo(relocType type, RawBitsToken ignore, int bits)
275 275 : _value((type << nontype_width) + bits) { }
276 276
277 277 relocInfo(relocType type, RawBitsToken ignore, int off, int f)
278 278 : _value((type << nontype_width) + (off / (unsigned)offset_unit) + (f << offset_width)) { }
279 279
280 280 public:
281 281 // constructor
282 282 relocInfo(relocType type, int offset, int format = 0)
283 283 #ifndef ASSERT
284 284 {
285 285 (*this) = relocInfo(type, RAW_BITS, offset, format);
286 286 }
287 287 #else
288 288 // Put a bunch of assertions out-of-line.
289 289 ;
290 290 #endif
291 291
292 292 #define APPLY_TO_RELOCATIONS(visitor) \
293 293 visitor(oop) \
294 294 visitor(virtual_call) \
295 295 visitor(opt_virtual_call) \
296 296 visitor(static_call) \
297 297 visitor(static_stub) \
298 298 visitor(runtime_call) \
299 299 visitor(external_word) \
300 300 visitor(internal_word) \
301 301 visitor(poll) \
302 302 visitor(poll_return) \
303 303 visitor(breakpoint) \
304 304 visitor(section_word) \
305 305
306 306
307 307 public:
308 308 enum {
309 309 value_width = sizeof(unsigned short) * BitsPerByte,
310 310 type_width = 4, // == log2(type_mask+1)
311 311 nontype_width = value_width - type_width,
312 312 datalen_width = nontype_width-1,
313 313 datalen_tag = 1 << datalen_width, // or-ed into _value
314 314 datalen_limit = 1 << datalen_width,
315 315 datalen_mask = (1 << datalen_width)-1
316 316 };
317 317
318 318 // accessors
319 319 public:
320 320 relocType type() const { return (relocType)((unsigned)_value >> nontype_width); }
321 321 int format() const { return format_mask==0? 0: format_mask &
322 322 ((unsigned)_value >> offset_width); }
323 323 int addr_offset() const { assert(!is_prefix(), "must have offset");
324 324 return (_value & offset_mask)*offset_unit; }
325 325
326 326 protected:
327 327 const short* data() const { assert(is_datalen(), "must have data");
328 328 return (const short*)(this + 1); }
329 329 int datalen() const { assert(is_datalen(), "must have data");
330 330 return (_value & datalen_mask); }
331 331 int immediate() const { assert(is_immediate(), "must have immed");
332 332 return (_value & datalen_mask); }
333 333 public:
334 334 static int addr_unit() { return offset_unit; }
335 335 static int offset_limit() { return (1 << offset_width) * offset_unit; }
336 336
337 337 void set_type(relocType type);
338 338 void set_format(int format);
339 339
340 340 void remove() { set_type(none); }
341 341
342 342 protected:
343 343 bool is_none() const { return type() == none; }
344 344 bool is_prefix() const { return type() == data_prefix_tag; }
345 345 bool is_datalen() const { assert(is_prefix(), "must be prefix");
346 346 return (_value & datalen_tag) != 0; }
347 347 bool is_immediate() const { assert(is_prefix(), "must be prefix");
348 348 return (_value & datalen_tag) == 0; }
349 349
350 350 public:
351 351 // Occasionally records of type relocInfo::none will appear in the stream.
352 352 // We do not bother to filter these out, but clients should ignore them.
353 353 // These records serve as "filler" in three ways:
354 354 // - to skip large spans of unrelocated code (this is rare)
355 355 // - to pad out the relocInfo array to the required oop alignment
356 356 // - to disable old relocation information which is no longer applicable
357 357
358 358 inline friend relocInfo filler_relocInfo();
359 359
360 360 // Every non-prefix relocation may be preceded by at most one prefix,
361 361 // which supplies 1 or more halfwords of associated data. Conventionally,
362 362 // an int is represented by 0, 1, or 2 halfwords, depending on how
363 363 // many bits are required to represent the value. (In addition,
364 364 // if the sole halfword is a 10-bit unsigned number, it is made
365 365 // "immediate" in the prefix header word itself. This optimization
366 366 // is invisible outside this module.)
367 367
368 368 inline friend relocInfo prefix_relocInfo(int datalen = 0);
369 369
370 370 protected:
371 371 // an immediate relocInfo optimizes a prefix with one 10-bit unsigned value
372 372 static relocInfo immediate_relocInfo(int data0) {
373 373 assert(fits_into_immediate(data0), "data0 in limits");
374 374 return relocInfo(relocInfo::data_prefix_tag, RAW_BITS, data0);
375 375 }
376 376 static bool fits_into_immediate(int data0) {
377 377 return (data0 >= 0 && data0 < datalen_limit);
378 378 }
379 379
380 380 public:
381 381 // Support routines for compilers.
382 382
383 383 // This routine takes an infant relocInfo (unprefixed) and
384 384 // edits in its prefix, if any. It also updates dest.locs_end.
385 385 void initialize(CodeSection* dest, Relocation* reloc);
386 386
387 387 // This routine updates a prefix and returns the limit pointer.
388 388 // It tries to compress the prefix from 32 to 16 bits, and if
389 389 // successful returns a reduced "prefix_limit" pointer.
390 390 relocInfo* finish_prefix(short* prefix_limit);
391 391
392 392 // bit-packers for the data array:
393 393
394 394 // As it happens, the bytes within the shorts are ordered natively,
395 395 // but the shorts within the word are ordered big-endian.
396 396 // This is an arbitrary choice, made this way mainly to ease debugging.
397 397 static int data0_from_int(jint x) { return x >> value_width; }
398 398 static int data1_from_int(jint x) { return (short)x; }
399 399 static jint jint_from_data(short* data) {
400 400 return (data[0] << value_width) + (unsigned short)data[1];
401 401 }
402 402
403 403 static jint short_data_at(int n, short* data, int datalen) {
404 404 return datalen > n ? data[n] : 0;
405 405 }
406 406
407 407 static jint jint_data_at(int n, short* data, int datalen) {
408 408 return datalen > n+1 ? jint_from_data(&data[n]) : short_data_at(n, data, datalen);
409 409 }
410 410
411 411 // Update methods for relocation information
412 412 // (since code is dynamically patched, we also need to dynamically update the relocation info)
413 413 // Both methods takes old_type, so it is able to performe sanity checks on the information removed.
414 414 static void change_reloc_info_for_address(RelocIterator *itr, address pc, relocType old_type, relocType new_type);
415 415 static void remove_reloc_info_for_address(RelocIterator *itr, address pc, relocType old_type);
416 416
417 417 // Machine dependent stuff
418 418 #include "incls/_relocInfo_pd.hpp.incl"
419 419
420 420 protected:
421 421 // Derived constant, based on format_width which is PD:
422 422 enum {
423 423 offset_width = nontype_width - format_width,
424 424 offset_mask = (1<<offset_width) - 1,
425 425 format_mask = (1<<format_width) - 1
426 426 };
427 427 public:
428 428 enum {
429 429 // Conservatively large estimate of maximum length (in shorts)
430 430 // of any relocation record (probably breakpoints are largest).
431 431 // Extended format is length prefix, data words, and tag/offset suffix.
432 432 length_limit = 1 + 1 + (3*BytesPerWord/BytesPerShort) + 1,
433 433 have_format = format_width > 0
434 434 };
435 435 };
436 436
437 437 #define FORWARD_DECLARE_EACH_CLASS(name) \
438 438 class name##_Relocation;
439 439 APPLY_TO_RELOCATIONS(FORWARD_DECLARE_EACH_CLASS)
440 440 #undef FORWARD_DECLARE_EACH_CLASS
441 441
442 442
443 443
444 444 inline relocInfo filler_relocInfo() {
445 445 return relocInfo(relocInfo::none, relocInfo::offset_limit() - relocInfo::offset_unit);
446 446 }
447 447
448 448 inline relocInfo prefix_relocInfo(int datalen) {
449 449 assert(relocInfo::fits_into_immediate(datalen), "datalen in limits");
450 450 return relocInfo(relocInfo::data_prefix_tag, relocInfo::RAW_BITS, relocInfo::datalen_tag | datalen);
451 451 }
452 452
453 453
454 454 // Holder for flyweight relocation objects.
455 455 // Although the flyweight subclasses are of varying sizes,
456 456 // the holder is "one size fits all".
457 457 class RelocationHolder VALUE_OBJ_CLASS_SPEC {
458 458 friend class Relocation;
459 459 friend class CodeSection;
460 460
461 461 private:
462 462 // this preallocated memory must accommodate all subclasses of Relocation
463 463 // (this number is assertion-checked in Relocation::operator new)
464 464 enum { _relocbuf_size = 5 };
465 465 void* _relocbuf[ _relocbuf_size ];
466 466
467 467 public:
468 468 Relocation* reloc() const { return (Relocation*) &_relocbuf[0]; }
469 469 inline relocInfo::relocType type() const;
470 470
471 471 // Add a constant offset to a relocation. Helper for class Address.
472 472 RelocationHolder plus(int offset) const;
473 473
474 474 inline RelocationHolder(); // initializes type to none
475 475
476 476 inline RelocationHolder(Relocation* r); // make a copy
477 477
478 478 static const RelocationHolder none;
479 479 };
480 480
481 481 // A RelocIterator iterates through the relocation information of a CodeBlob.
482 482 // It is a variable BoundRelocation which is able to take on successive
483 483 // values as it is advanced through a code stream.
484 484 // Usage:
485 485 // RelocIterator iter(nm);
486 486 // while (iter.next()) {
487 487 // iter.reloc()->some_operation();
488 488 // }
489 489 // or:
490 490 // RelocIterator iter(nm);
491 491 // while (iter.next()) {
492 492 // switch (iter.type()) {
493 493 // case relocInfo::oop_type :
494 494 // case relocInfo::ic_type :
495 495 // case relocInfo::prim_type :
496 496 // case relocInfo::uncommon_type :
497 497 // case relocInfo::runtime_call_type :
498 498 // case relocInfo::internal_word_type:
499 499 // case relocInfo::external_word_type:
500 500 // ...
501 501 // }
502 502 // }
503 503
504 504 class RelocIterator : public StackObj {
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505 505 enum { SECT_CONSTS = 2,
506 506 SECT_LIMIT = 3 }; // must be equal to CodeBuffer::SECT_LIMIT
507 507 friend class Relocation;
508 508 friend class relocInfo; // for change_reloc_info_for_address only
509 509 typedef relocInfo::relocType relocType;
510 510
511 511 private:
512 512 address _limit; // stop producing relocations after this _addr
513 513 relocInfo* _current; // the current relocation information
514 514 relocInfo* _end; // end marker; we're done iterating when _current == _end
515 - CodeBlob* _code; // compiled method containing _addr
515 + nmethod* _code; // compiled method containing _addr
516 516 address _addr; // instruction to which the relocation applies
517 517 short _databuf; // spare buffer for compressed data
518 518 short* _data; // pointer to the relocation's data
519 519 short _datalen; // number of halfwords in _data
520 520 char _format; // position within the instruction
521 521
522 522 // Base addresses needed to compute targets of section_word_type relocs.
523 523 address _section_start[SECT_LIMIT];
524 524
525 525 void set_has_current(bool b) {
526 526 _datalen = !b ? -1 : 0;
527 527 debug_only(_data = NULL);
528 528 }
529 529 void set_current(relocInfo& ri) {
530 530 _current = &ri;
531 531 set_has_current(true);
532 532 }
533 533
534 534 RelocationHolder _rh; // where the current relocation is allocated
535 535
536 536 relocInfo* current() const { assert(has_current(), "must have current");
537 537 return _current; }
538 538
539 539 void set_limits(address begin, address limit);
540 540
541 541 void advance_over_prefix(); // helper method
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542 542
543 543 void initialize_misc() {
544 544 set_has_current(false);
545 545 for (int i = 0; i < SECT_LIMIT; i++) {
546 546 _section_start[i] = NULL; // these will be lazily computed, if needed
547 547 }
548 548 }
549 549
550 550 address compute_section_start(int n) const; // out-of-line helper
551 551
552 - void initialize(CodeBlob* nm, address begin, address limit);
552 + void initialize(nmethod* nm, address begin, address limit);
553 553
554 554 friend class PatchingRelocIterator;
555 555 // make an uninitialized one, for PatchingRelocIterator:
556 556 RelocIterator() { initialize_misc(); }
557 557
558 558 public:
559 559 // constructor
560 - RelocIterator(CodeBlob* cb, address begin = NULL, address limit = NULL);
560 + RelocIterator(nmethod* nm, address begin = NULL, address limit = NULL);
561 561 RelocIterator(CodeSection* cb, address begin = NULL, address limit = NULL);
562 562
563 563 // get next reloc info, return !eos
564 564 bool next() {
565 565 _current++;
566 566 assert(_current <= _end, "must not overrun relocInfo");
567 567 if (_current == _end) {
568 568 set_has_current(false);
569 569 return false;
570 570 }
571 571 set_has_current(true);
572 572
573 573 if (_current->is_prefix()) {
574 574 advance_over_prefix();
575 575 assert(!current()->is_prefix(), "only one prefix at a time");
576 576 }
577 577
578 578 _addr += _current->addr_offset();
579 579
580 580 if (_limit != NULL && _addr >= _limit) {
581 581 set_has_current(false);
582 582 return false;
583 583 }
584 584
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585 585 if (relocInfo::have_format) _format = current()->format();
586 586 return true;
587 587 }
588 588
589 589 // accessors
590 590 address limit() const { return _limit; }
591 591 void set_limit(address x);
592 592 relocType type() const { return current()->type(); }
593 593 int format() const { return (relocInfo::have_format) ? current()->format() : 0; }
594 594 address addr() const { return _addr; }
595 - CodeBlob* code() const { return _code; }
595 + nmethod* code() const { return _code; }
596 596 short* data() const { return _data; }
597 597 int datalen() const { return _datalen; }
598 598 bool has_current() const { return _datalen >= 0; }
599 599
600 600 void set_addr(address addr) { _addr = addr; }
601 601 bool addr_in_const() const { return addr() >= section_start(SECT_CONSTS); }
602 602
603 603 address section_start(int n) const {
604 604 address res = _section_start[n];
605 605 return (res != NULL) ? res : compute_section_start(n);
606 606 }
607 607
608 608 // The address points to the affected displacement part of the instruction.
609 609 // For RISC, this is just the whole instruction.
610 610 // For Intel, this is an unaligned 32-bit word.
611 611
612 612 // type-specific relocation accessors: oop_Relocation* oop_reloc(), etc.
613 613 #define EACH_TYPE(name) \
614 614 inline name##_Relocation* name##_reloc();
615 615 APPLY_TO_RELOCATIONS(EACH_TYPE)
616 616 #undef EACH_TYPE
617 617 // generic relocation accessor; switches on type to call the above
618 618 Relocation* reloc();
619 619
620 620 // CodeBlob's have relocation indexes for faster random access:
621 621 static int locs_and_index_size(int code_size, int locs_size);
622 622 // Store an index into [dest_start+dest_count..dest_end).
623 623 // At dest_start[0..dest_count] is the actual relocation information.
624 624 // Everything else up to dest_end is free space for the index.
625 625 static void create_index(relocInfo* dest_begin, int dest_count, relocInfo* dest_end);
626 626
627 627 #ifndef PRODUCT
628 628 public:
629 629 void print();
630 630 void print_current();
631 631 #endif
632 632 };
633 633
634 634
635 635 // A Relocation is a flyweight object allocated within a RelocationHolder.
636 636 // It represents the relocation data of relocation record.
637 637 // So, the RelocIterator unpacks relocInfos into Relocations.
638 638
639 639 class Relocation VALUE_OBJ_CLASS_SPEC {
640 640 friend class RelocationHolder;
641 641 friend class RelocIterator;
642 642
643 643 private:
644 644 static void guarantee_size();
645 645
646 646 // When a relocation has been created by a RelocIterator,
647 647 // this field is non-null. It allows the relocation to know
648 648 // its context, such as the address to which it applies.
649 649 RelocIterator* _binding;
650 650
651 651 protected:
652 652 RelocIterator* binding() const {
653 653 assert(_binding != NULL, "must be bound");
654 654 return _binding;
655 655 }
656 656 void set_binding(RelocIterator* b) {
657 657 assert(_binding == NULL, "must be unbound");
658 658 _binding = b;
659 659 assert(_binding != NULL, "must now be bound");
660 660 }
661 661
662 662 Relocation() {
663 663 _binding = NULL;
664 664 }
665 665
666 666 static RelocationHolder newHolder() {
667 667 return RelocationHolder();
668 668 }
669 669
670 670 public:
671 671 void* operator new(size_t size, const RelocationHolder& holder) {
672 672 if (size > sizeof(holder._relocbuf)) guarantee_size();
673 673 assert((void* const *)holder.reloc() == &holder._relocbuf[0], "ptrs must agree");
674 674 return holder.reloc();
675 675 }
676 676
677 677 // make a generic relocation for a given type (if possible)
678 678 static RelocationHolder spec_simple(relocInfo::relocType rtype);
679 679
680 680 // here is the type-specific hook which writes relocation data:
681 681 virtual void pack_data_to(CodeSection* dest) { }
682 682
683 683 // here is the type-specific hook which reads (unpacks) relocation data:
684 684 virtual void unpack_data() {
685 685 assert(datalen()==0 || type()==relocInfo::none, "no data here");
686 686 }
687 687
688 688 protected:
689 689 // Helper functions for pack_data_to() and unpack_data().
690 690
691 691 // Most of the compression logic is confined here.
692 692 // (The "immediate data" mechanism of relocInfo works independently
693 693 // of this stuff, and acts to further compress most 1-word data prefixes.)
694 694
695 695 // A variable-width int is encoded as a short if it will fit in 16 bits.
696 696 // The decoder looks at datalen to decide whether to unpack short or jint.
697 697 // Most relocation records are quite simple, containing at most two ints.
698 698
699 699 static bool is_short(jint x) { return x == (short)x; }
700 700 static short* add_short(short* p, int x) { *p++ = x; return p; }
701 701 static short* add_jint (short* p, jint x) {
702 702 *p++ = relocInfo::data0_from_int(x); *p++ = relocInfo::data1_from_int(x);
703 703 return p;
704 704 }
705 705 static short* add_var_int(short* p, jint x) { // add a variable-width int
706 706 if (is_short(x)) p = add_short(p, x);
707 707 else p = add_jint (p, x);
708 708 return p;
709 709 }
710 710
711 711 static short* pack_1_int_to(short* p, jint x0) {
712 712 // Format is one of: [] [x] [Xx]
713 713 if (x0 != 0) p = add_var_int(p, x0);
714 714 return p;
715 715 }
716 716 int unpack_1_int() {
717 717 assert(datalen() <= 2, "too much data");
718 718 return relocInfo::jint_data_at(0, data(), datalen());
719 719 }
720 720
721 721 // With two ints, the short form is used only if both ints are short.
722 722 short* pack_2_ints_to(short* p, jint x0, jint x1) {
723 723 // Format is one of: [] [x y?] [Xx Y?y]
724 724 if (x0 == 0 && x1 == 0) {
725 725 // no halfwords needed to store zeroes
726 726 } else if (is_short(x0) && is_short(x1)) {
727 727 // 1-2 halfwords needed to store shorts
728 728 p = add_short(p, x0); if (x1!=0) p = add_short(p, x1);
729 729 } else {
730 730 // 3-4 halfwords needed to store jints
731 731 p = add_jint(p, x0); p = add_var_int(p, x1);
732 732 }
733 733 return p;
734 734 }
735 735 void unpack_2_ints(jint& x0, jint& x1) {
736 736 int dlen = datalen();
737 737 short* dp = data();
738 738 if (dlen <= 2) {
739 739 x0 = relocInfo::short_data_at(0, dp, dlen);
740 740 x1 = relocInfo::short_data_at(1, dp, dlen);
741 741 } else {
742 742 assert(dlen <= 4, "too much data");
743 743 x0 = relocInfo::jint_data_at(0, dp, dlen);
744 744 x1 = relocInfo::jint_data_at(2, dp, dlen);
745 745 }
746 746 }
747 747
748 748 protected:
749 749 // platform-dependent utilities for decoding and patching instructions
750 750 void pd_set_data_value (address x, intptr_t off); // a set or mem-ref
751 751 address pd_call_destination (address orig_addr = NULL);
752 752 void pd_set_call_destination (address x);
753 753 void pd_swap_in_breakpoint (address x, short* instrs, int instrlen);
754 754 void pd_swap_out_breakpoint (address x, short* instrs, int instrlen);
755 755 static int pd_breakpoint_size ();
756 756
757 757 // this extracts the address of an address in the code stream instead of the reloc data
758 758 address* pd_address_in_code ();
759 759
760 760 // this extracts an address from the code stream instead of the reloc data
761 761 address pd_get_address_from_code ();
762 762
763 763 // these convert from byte offsets, to scaled offsets, to addresses
764 764 static jint scaled_offset(address x, address base) {
765 765 int byte_offset = x - base;
766 766 int offset = -byte_offset / relocInfo::addr_unit();
767 767 assert(address_from_scaled_offset(offset, base) == x, "just checkin'");
768 768 return offset;
769 769 }
770 770 static jint scaled_offset_null_special(address x, address base) {
771 771 // Some relocations treat offset=0 as meaning NULL.
772 772 // Handle this extra convention carefully.
773 773 if (x == NULL) return 0;
774 774 assert(x != base, "offset must not be zero");
775 775 return scaled_offset(x, base);
776 776 }
777 777 static address address_from_scaled_offset(jint offset, address base) {
778 778 int byte_offset = -( offset * relocInfo::addr_unit() );
779 779 return base + byte_offset;
780 780 }
781 781
782 782 // these convert between indexes and addresses in the runtime system
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783 783 static int32_t runtime_address_to_index(address runtime_address);
784 784 static address index_to_runtime_address(int32_t index);
785 785
786 786 // helpers for mapping between old and new addresses after a move or resize
787 787 address old_addr_for(address newa, const CodeBuffer* src, CodeBuffer* dest);
788 788 address new_addr_for(address olda, const CodeBuffer* src, CodeBuffer* dest);
789 789 void normalize_address(address& addr, const CodeSection* dest, bool allow_other_sections = false);
790 790
791 791 public:
792 792 // accessors which only make sense for a bound Relocation
793 - address addr() const { return binding()->addr(); }
794 - CodeBlob* code() const { return binding()->code(); }
795 - bool addr_in_const() const { return binding()->addr_in_const(); }
793 + address addr() const { return binding()->addr(); }
794 + nmethod* code() const { return binding()->code(); }
795 + bool addr_in_const() const { return binding()->addr_in_const(); }
796 796 protected:
797 797 short* data() const { return binding()->data(); }
798 798 int datalen() const { return binding()->datalen(); }
799 799 int format() const { return binding()->format(); }
800 800
801 801 public:
802 802 virtual relocInfo::relocType type() { return relocInfo::none; }
803 803
804 804 // is it a call instruction?
805 805 virtual bool is_call() { return false; }
806 806
807 807 // is it a data movement instruction?
808 808 virtual bool is_data() { return false; }
809 809
810 810 // some relocations can compute their own values
811 811 virtual address value();
812 812
813 813 // all relocations are able to reassert their values
814 814 virtual void set_value(address x);
815 815
816 816 virtual void clear_inline_cache() { }
817 817
818 818 // This method assumes that all virtual/static (inline) caches are cleared (since for static_call_type and
819 819 // ic_call_type is not always posisition dependent (depending on the state of the cache)). However, this is
820 820 // probably a reasonable assumption, since empty caches simplifies code reloacation.
821 821 virtual void fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest) { }
822 822
823 823 void print();
824 824 };
825 825
826 826
827 827 // certain inlines must be deferred until class Relocation is defined:
828 828
829 829 inline RelocationHolder::RelocationHolder() {
830 830 // initialize the vtbl, just to keep things type-safe
831 831 new(*this) Relocation();
832 832 }
833 833
834 834
835 835 inline RelocationHolder::RelocationHolder(Relocation* r) {
836 836 // wordwise copy from r (ok if it copies garbage after r)
837 837 for (int i = 0; i < _relocbuf_size; i++) {
838 838 _relocbuf[i] = ((void**)r)[i];
839 839 }
840 840 }
841 841
842 842
843 843 relocInfo::relocType RelocationHolder::type() const {
844 844 return reloc()->type();
845 845 }
846 846
847 847 // A DataRelocation always points at a memory or load-constant instruction..
848 848 // It is absolute on most machines, and the constant is split on RISCs.
849 849 // The specific subtypes are oop, external_word, and internal_word.
850 850 // By convention, the "value" does not include a separately reckoned "offset".
851 851 class DataRelocation : public Relocation {
852 852 public:
853 853 bool is_data() { return true; }
854 854
855 855 // both target and offset must be computed somehow from relocation data
856 856 virtual int offset() { return 0; }
857 857 address value() = 0;
858 858 void set_value(address x) { set_value(x, offset()); }
859 859 void set_value(address x, intptr_t o) {
860 860 if (addr_in_const())
861 861 *(address*)addr() = x;
862 862 else
863 863 pd_set_data_value(x, o);
864 864 }
865 865
866 866 // The "o" (displacement) argument is relevant only to split relocations
867 867 // on RISC machines. In some CPUs (SPARC), the set-hi and set-lo ins'ns
868 868 // can encode more than 32 bits between them. This allows compilers to
869 869 // share set-hi instructions between addresses that differ by a small
870 870 // offset (e.g., different static variables in the same class).
871 871 // On such machines, the "x" argument to set_value on all set-lo
872 872 // instructions must be the same as the "x" argument for the
873 873 // corresponding set-hi instructions. The "o" arguments for the
874 874 // set-hi instructions are ignored, and must not affect the high-half
875 875 // immediate constant. The "o" arguments for the set-lo instructions are
876 876 // added into the low-half immediate constant, and must not overflow it.
877 877 };
878 878
879 879 // A CallRelocation always points at a call instruction.
880 880 // It is PC-relative on most machines.
881 881 class CallRelocation : public Relocation {
882 882 public:
883 883 bool is_call() { return true; }
884 884
885 885 address destination() { return pd_call_destination(); }
886 886 void set_destination(address x); // pd_set_call_destination
887 887
888 888 void fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest);
889 889 address value() { return destination(); }
890 890 void set_value(address x) { set_destination(x); }
891 891 };
892 892
893 893 class oop_Relocation : public DataRelocation {
894 894 relocInfo::relocType type() { return relocInfo::oop_type; }
895 895
896 896 public:
897 897 // encode in one of these formats: [] [n] [n l] [Nn l] [Nn Ll]
898 898 // an oop in the CodeBlob's oop pool
899 899 static RelocationHolder spec(int oop_index, int offset = 0) {
900 900 assert(oop_index > 0, "must be a pool-resident oop");
901 901 RelocationHolder rh = newHolder();
902 902 new(rh) oop_Relocation(oop_index, offset);
903 903 return rh;
904 904 }
905 905 // an oop in the instruction stream
906 906 static RelocationHolder spec_for_immediate() {
907 907 const int oop_index = 0;
908 908 const int offset = 0; // if you want an offset, use the oop pool
909 909 RelocationHolder rh = newHolder();
910 910 new(rh) oop_Relocation(oop_index, offset);
911 911 return rh;
912 912 }
913 913
914 914 private:
915 915 jint _oop_index; // if > 0, index into CodeBlob::oop_at
916 916 jint _offset; // byte offset to apply to the oop itself
917 917
918 918 oop_Relocation(int oop_index, int offset) {
919 919 _oop_index = oop_index; _offset = offset;
920 920 }
921 921
922 922 friend class RelocIterator;
923 923 oop_Relocation() { }
924 924
925 925 public:
926 926 int oop_index() { return _oop_index; }
927 927 int offset() { return _offset; }
928 928
929 929 // data is packed in "2_ints" format: [i o] or [Ii Oo]
930 930 void pack_data_to(CodeSection* dest);
931 931 void unpack_data();
932 932
933 933 void fix_oop_relocation(); // reasserts oop value
934 934
935 935 address value() { return (address) *oop_addr(); }
936 936
937 937 bool oop_is_immediate() { return oop_index() == 0; }
938 938
939 939 oop* oop_addr(); // addr or &pool[jint_data]
940 940 oop oop_value(); // *oop_addr
941 941 // Note: oop_value transparently converts Universe::non_oop_word to NULL.
942 942 };
943 943
944 944 class virtual_call_Relocation : public CallRelocation {
945 945 relocInfo::relocType type() { return relocInfo::virtual_call_type; }
946 946
947 947 public:
948 948 // "first_oop" points to the first associated set-oop.
949 949 // The oop_limit helps find the last associated set-oop.
950 950 // (See comments at the top of this file.)
951 951 static RelocationHolder spec(address first_oop, address oop_limit = NULL) {
952 952 RelocationHolder rh = newHolder();
953 953 new(rh) virtual_call_Relocation(first_oop, oop_limit);
954 954 return rh;
955 955 }
956 956
957 957 virtual_call_Relocation(address first_oop, address oop_limit) {
958 958 _first_oop = first_oop; _oop_limit = oop_limit;
959 959 assert(first_oop != NULL, "first oop address must be specified");
960 960 }
961 961
962 962 private:
963 963 address _first_oop; // location of first set-oop instruction
964 964 address _oop_limit; // search limit for set-oop instructions
965 965
966 966 friend class RelocIterator;
967 967 virtual_call_Relocation() { }
968 968
969 969
970 970 public:
971 971 address first_oop();
972 972 address oop_limit();
973 973
974 974 // data is packed as scaled offsets in "2_ints" format: [f l] or [Ff Ll]
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975 975 // oop_limit is set to 0 if the limit falls somewhere within the call.
976 976 // When unpacking, a zero oop_limit is taken to refer to the end of the call.
977 977 // (This has the effect of bringing in the call's delay slot on SPARC.)
978 978 void pack_data_to(CodeSection* dest);
979 979 void unpack_data();
980 980
981 981 void clear_inline_cache();
982 982
983 983 // Figure out where an ic_call is hiding, given a set-oop or call.
984 984 // Either ic_call or first_oop must be non-null; the other is deduced.
985 - // Code if non-NULL must be the CodeBlob, else it is deduced.
985 + // Code if non-NULL must be the nmethod, else it is deduced.
986 986 // The address of the patchable oop is also deduced.
987 987 // The returned iterator will enumerate over the oops and the ic_call,
988 988 // as well as any other relocations that happen to be in that span of code.
989 989 // Recognize relevant set_oops with: oop_reloc()->oop_addr() == oop_addr.
990 - static RelocIterator parse_ic(CodeBlob* &code, address &ic_call, address &first_oop, oop* &oop_addr, bool *is_optimized);
990 + static RelocIterator parse_ic(nmethod* &nm, address &ic_call, address &first_oop, oop* &oop_addr, bool *is_optimized);
991 991 };
992 992
993 993
994 994 class opt_virtual_call_Relocation : public CallRelocation {
995 995 relocInfo::relocType type() { return relocInfo::opt_virtual_call_type; }
996 996
997 997 public:
998 998 static RelocationHolder spec() {
999 999 RelocationHolder rh = newHolder();
1000 1000 new(rh) opt_virtual_call_Relocation();
1001 1001 return rh;
1002 1002 }
1003 1003
1004 1004 private:
1005 1005 friend class RelocIterator;
1006 1006 opt_virtual_call_Relocation() { }
1007 1007
1008 1008 public:
1009 1009 void clear_inline_cache();
1010 1010
1011 1011 // find the matching static_stub
1012 1012 address static_stub();
1013 1013 };
1014 1014
1015 1015
1016 1016 class static_call_Relocation : public CallRelocation {
1017 1017 relocInfo::relocType type() { return relocInfo::static_call_type; }
1018 1018
1019 1019 public:
1020 1020 static RelocationHolder spec() {
1021 1021 RelocationHolder rh = newHolder();
1022 1022 new(rh) static_call_Relocation();
1023 1023 return rh;
1024 1024 }
1025 1025
1026 1026 private:
1027 1027 friend class RelocIterator;
1028 1028 static_call_Relocation() { }
1029 1029
1030 1030 public:
1031 1031 void clear_inline_cache();
1032 1032
1033 1033 // find the matching static_stub
1034 1034 address static_stub();
1035 1035 };
1036 1036
1037 1037 class static_stub_Relocation : public Relocation {
1038 1038 relocInfo::relocType type() { return relocInfo::static_stub_type; }
1039 1039
1040 1040 public:
1041 1041 static RelocationHolder spec(address static_call) {
1042 1042 RelocationHolder rh = newHolder();
1043 1043 new(rh) static_stub_Relocation(static_call);
1044 1044 return rh;
1045 1045 }
1046 1046
1047 1047 private:
1048 1048 address _static_call; // location of corresponding static_call
1049 1049
1050 1050 static_stub_Relocation(address static_call) {
1051 1051 _static_call = static_call;
1052 1052 }
1053 1053
1054 1054 friend class RelocIterator;
1055 1055 static_stub_Relocation() { }
1056 1056
1057 1057 public:
1058 1058 void clear_inline_cache();
1059 1059
1060 1060 address static_call() { return _static_call; }
1061 1061
1062 1062 // data is packed as a scaled offset in "1_int" format: [c] or [Cc]
1063 1063 void pack_data_to(CodeSection* dest);
1064 1064 void unpack_data();
1065 1065 };
1066 1066
1067 1067 class runtime_call_Relocation : public CallRelocation {
1068 1068 relocInfo::relocType type() { return relocInfo::runtime_call_type; }
1069 1069
1070 1070 public:
1071 1071 static RelocationHolder spec() {
1072 1072 RelocationHolder rh = newHolder();
1073 1073 new(rh) runtime_call_Relocation();
1074 1074 return rh;
1075 1075 }
1076 1076
1077 1077 private:
1078 1078 friend class RelocIterator;
1079 1079 runtime_call_Relocation() { }
1080 1080
1081 1081 public:
1082 1082 };
1083 1083
1084 1084 class external_word_Relocation : public DataRelocation {
1085 1085 relocInfo::relocType type() { return relocInfo::external_word_type; }
1086 1086
1087 1087 public:
1088 1088 static RelocationHolder spec(address target) {
1089 1089 assert(target != NULL, "must not be null");
1090 1090 RelocationHolder rh = newHolder();
1091 1091 new(rh) external_word_Relocation(target);
1092 1092 return rh;
1093 1093 }
1094 1094
1095 1095 // Use this one where all 32/64 bits of the target live in the code stream.
1096 1096 // The target must be an intptr_t, and must be absolute (not relative).
1097 1097 static RelocationHolder spec_for_immediate() {
1098 1098 RelocationHolder rh = newHolder();
1099 1099 new(rh) external_word_Relocation(NULL);
1100 1100 return rh;
1101 1101 }
1102 1102
1103 1103 private:
1104 1104 address _target; // address in runtime
1105 1105
1106 1106 external_word_Relocation(address target) {
1107 1107 _target = target;
1108 1108 }
1109 1109
1110 1110 friend class RelocIterator;
1111 1111 external_word_Relocation() { }
1112 1112
1113 1113 public:
1114 1114 // data is packed as a well-known address in "1_int" format: [a] or [Aa]
1115 1115 // The function runtime_address_to_index is used to turn full addresses
1116 1116 // to short indexes, if they are pre-registered by the stub mechanism.
1117 1117 // If the "a" value is 0 (i.e., _target is NULL), the address is stored
1118 1118 // in the code stream. See external_word_Relocation::target().
1119 1119 void pack_data_to(CodeSection* dest);
1120 1120 void unpack_data();
1121 1121
1122 1122 void fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest);
1123 1123 address target(); // if _target==NULL, fetch addr from code stream
1124 1124 address value() { return target(); }
1125 1125 };
1126 1126
1127 1127 class internal_word_Relocation : public DataRelocation {
1128 1128 relocInfo::relocType type() { return relocInfo::internal_word_type; }
1129 1129
1130 1130 public:
1131 1131 static RelocationHolder spec(address target) {
1132 1132 assert(target != NULL, "must not be null");
1133 1133 RelocationHolder rh = newHolder();
1134 1134 new(rh) internal_word_Relocation(target);
1135 1135 return rh;
1136 1136 }
1137 1137
1138 1138 // use this one where all the bits of the target can fit in the code stream:
1139 1139 static RelocationHolder spec_for_immediate() {
1140 1140 RelocationHolder rh = newHolder();
1141 1141 new(rh) internal_word_Relocation(NULL);
1142 1142 return rh;
1143 1143 }
1144 1144
1145 1145 internal_word_Relocation(address target) {
1146 1146 _target = target;
1147 1147 _section = -1; // self-relative
1148 1148 }
1149 1149
1150 1150 protected:
1151 1151 address _target; // address in CodeBlob
1152 1152 int _section; // section providing base address, if any
1153 1153
1154 1154 friend class RelocIterator;
1155 1155 internal_word_Relocation() { }
1156 1156
1157 1157 // bit-width of LSB field in packed offset, if section >= 0
1158 1158 enum { section_width = 2 }; // must equal CodeBuffer::sect_bits
1159 1159
1160 1160 public:
1161 1161 // data is packed as a scaled offset in "1_int" format: [o] or [Oo]
1162 1162 // If the "o" value is 0 (i.e., _target is NULL), the offset is stored
1163 1163 // in the code stream. See internal_word_Relocation::target().
1164 1164 // If _section is not -1, it is appended to the low bits of the offset.
1165 1165 void pack_data_to(CodeSection* dest);
1166 1166 void unpack_data();
1167 1167
1168 1168 void fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest);
1169 1169 address target(); // if _target==NULL, fetch addr from code stream
1170 1170 int section() { return _section; }
1171 1171 address value() { return target(); }
1172 1172 };
1173 1173
1174 1174 class section_word_Relocation : public internal_word_Relocation {
1175 1175 relocInfo::relocType type() { return relocInfo::section_word_type; }
1176 1176
1177 1177 public:
1178 1178 static RelocationHolder spec(address target, int section) {
1179 1179 RelocationHolder rh = newHolder();
1180 1180 new(rh) section_word_Relocation(target, section);
1181 1181 return rh;
1182 1182 }
1183 1183
1184 1184 section_word_Relocation(address target, int section) {
1185 1185 assert(target != NULL, "must not be null");
1186 1186 assert(section >= 0, "must be a valid section");
1187 1187 _target = target;
1188 1188 _section = section;
1189 1189 }
1190 1190
1191 1191 //void pack_data_to -- inherited
1192 1192 void unpack_data();
1193 1193
1194 1194 private:
1195 1195 friend class RelocIterator;
1196 1196 section_word_Relocation() { }
1197 1197 };
1198 1198
1199 1199
1200 1200 class poll_Relocation : public Relocation {
1201 1201 bool is_data() { return true; }
1202 1202 relocInfo::relocType type() { return relocInfo::poll_type; }
1203 1203 void fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest);
1204 1204 };
1205 1205
1206 1206 class poll_return_Relocation : public Relocation {
1207 1207 bool is_data() { return true; }
1208 1208 relocInfo::relocType type() { return relocInfo::poll_return_type; }
1209 1209 void fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest);
1210 1210 };
1211 1211
1212 1212
1213 1213 class breakpoint_Relocation : public Relocation {
1214 1214 relocInfo::relocType type() { return relocInfo::breakpoint_type; }
1215 1215
1216 1216 enum {
1217 1217 // attributes which affect the interpretation of the data:
1218 1218 removable_attr = 0x0010, // buffer [i...] allows for undoing the trap
1219 1219 internal_attr = 0x0020, // the target is an internal addr (local stub)
1220 1220 settable_attr = 0x0040, // the target is settable
1221 1221
1222 1222 // states which can change over time:
1223 1223 enabled_state = 0x0100, // breakpoint must be active in running code
1224 1224 active_state = 0x0200, // breakpoint instruction actually in code
1225 1225
1226 1226 kind_mask = 0x000F, // mask for extracting kind
1227 1227 high_bit = 0x4000 // extra bit which is always set
1228 1228 };
1229 1229
1230 1230 public:
1231 1231 enum {
1232 1232 // kinds:
1233 1233 initialization = 1,
1234 1234 safepoint = 2
1235 1235 };
1236 1236
1237 1237 // If target is NULL, 32 bits are reserved for a later set_target().
1238 1238 static RelocationHolder spec(int kind, address target = NULL, bool internal_target = false) {
1239 1239 RelocationHolder rh = newHolder();
1240 1240 new(rh) breakpoint_Relocation(kind, target, internal_target);
1241 1241 return rh;
1242 1242 }
1243 1243
1244 1244 private:
1245 1245 // We require every bits value to NOT to fit into relocInfo::datalen_width,
1246 1246 // because we are going to actually store state in the reloc, and so
1247 1247 // cannot allow it to be compressed (and hence copied by the iterator).
1248 1248
1249 1249 short _bits; // bit-encoded kind, attrs, & state
1250 1250 address _target;
1251 1251
1252 1252 breakpoint_Relocation(int kind, address target, bool internal_target);
1253 1253
1254 1254 friend class RelocIterator;
1255 1255 breakpoint_Relocation() { }
1256 1256
1257 1257 short bits() const { return _bits; }
1258 1258 short& live_bits() const { return data()[0]; }
1259 1259 short* instrs() const { return data() + datalen() - instrlen(); }
1260 1260 int instrlen() const { return removable() ? pd_breakpoint_size() : 0; }
1261 1261
1262 1262 void set_bits(short x) {
1263 1263 assert(live_bits() == _bits, "must be the only mutator of reloc info");
1264 1264 live_bits() = _bits = x;
1265 1265 }
1266 1266
1267 1267 public:
1268 1268 address target() const;
1269 1269 void set_target(address x);
1270 1270
1271 1271 int kind() const { return bits() & kind_mask; }
1272 1272 bool enabled() const { return (bits() & enabled_state) != 0; }
1273 1273 bool active() const { return (bits() & active_state) != 0; }
1274 1274 bool internal() const { return (bits() & internal_attr) != 0; }
1275 1275 bool removable() const { return (bits() & removable_attr) != 0; }
1276 1276 bool settable() const { return (bits() & settable_attr) != 0; }
1277 1277
1278 1278 void set_enabled(bool b); // to activate, you must also say set_active
1279 1279 void set_active(bool b); // actually inserts bpt (must be enabled 1st)
1280 1280
1281 1281 // data is packed as 16 bits, followed by the target (1 or 2 words), followed
1282 1282 // if necessary by empty storage for saving away original instruction bytes.
1283 1283 void pack_data_to(CodeSection* dest);
1284 1284 void unpack_data();
1285 1285
1286 1286 // during certain operations, breakpoints must be out of the way:
1287 1287 void fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest) {
1288 1288 assert(!active(), "cannot perform relocation on enabled breakpoints");
1289 1289 }
1290 1290 };
1291 1291
1292 1292
1293 1293 // We know all the xxx_Relocation classes, so now we can define these:
1294 1294 #define EACH_CASE(name) \
1295 1295 inline name##_Relocation* RelocIterator::name##_reloc() { \
1296 1296 assert(type() == relocInfo::name##_type, "type must agree"); \
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1297 1297 /* The purpose of the placed "new" is to re-use the same */ \
1298 1298 /* stack storage for each new iteration. */ \
1299 1299 name##_Relocation* r = new(_rh) name##_Relocation(); \
1300 1300 r->set_binding(this); \
1301 1301 r->name##_Relocation::unpack_data(); \
1302 1302 return r; \
1303 1303 }
1304 1304 APPLY_TO_RELOCATIONS(EACH_CASE);
1305 1305 #undef EACH_CASE
1306 1306
1307 -inline RelocIterator::RelocIterator(CodeBlob* cb, address begin, address limit) {
1308 - initialize(cb, begin, limit);
1307 +inline RelocIterator::RelocIterator(nmethod* nm, address begin, address limit) {
1308 + initialize(nm, begin, limit);
1309 1309 }
1310 1310
1311 1311 // if you are going to patch code, you should use this subclass of
1312 1312 // RelocIterator
1313 1313 class PatchingRelocIterator : public RelocIterator {
1314 1314 private:
1315 1315 RelocIterator _init_state;
1316 1316
1317 1317 void prepass(); // deactivates all breakpoints
1318 1318 void postpass(); // reactivates all enabled breakpoints
1319 1319
1320 1320 // do not copy these puppies; it would have unpredictable side effects
1321 1321 // these are private and have no bodies defined because they should not be called
1322 1322 PatchingRelocIterator(const RelocIterator&);
1323 1323 void operator=(const RelocIterator&);
1324 1324
1325 1325 public:
1326 - PatchingRelocIterator(CodeBlob* cb, address begin =NULL, address limit =NULL)
1327 - : RelocIterator(cb, begin, limit) { prepass(); }
1326 + PatchingRelocIterator(nmethod* nm, address begin = NULL, address limit = NULL)
1327 + : RelocIterator(nm, begin, limit) { prepass(); }
1328 1328
1329 1329 ~PatchingRelocIterator() { postpass(); }
1330 1330 };
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