Mercurial > hg > graal-compiler
comparison src/share/vm/code/relocInfo.hpp @ 0:a61af66fc99e jdk7-b24
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author | duke |
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date | Sat, 01 Dec 2007 00:00:00 +0000 |
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children | dc7f315e41f7 |
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1 /* | |
2 * Copyright 1997-2006 Sun Microsystems, Inc. All Rights Reserved. | |
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. | |
4 * | |
5 * This code is free software; you can redistribute it and/or modify it | |
6 * under the terms of the GNU General Public License version 2 only, as | |
7 * published by the Free Software Foundation. | |
8 * | |
9 * This code is distributed in the hope that it will be useful, but WITHOUT | |
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
12 * version 2 for more details (a copy is included in the LICENSE file that | |
13 * accompanied this code). | |
14 * | |
15 * You should have received a copy of the GNU General Public License version | |
16 * 2 along with this work; if not, write to the Free Software Foundation, | |
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | |
18 * | |
19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, | |
20 * CA 95054 USA or visit www.sun.com if you need additional information or | |
21 * have any questions. | |
22 * | |
23 */ | |
24 | |
25 // Types in this file: | |
26 // relocInfo | |
27 // One element of an array of halfwords encoding compressed relocations. | |
28 // Also, the source of relocation types (relocInfo::oop_type, ...). | |
29 // Relocation | |
30 // A flyweight object representing a single relocation. | |
31 // It is fully unpacked from the compressed relocation array. | |
32 // oop_Relocation, ... (subclasses of Relocation) | |
33 // The location of some type-specific operations (oop_addr, ...). | |
34 // Also, the source of relocation specs (oop_Relocation::spec, ...). | |
35 // RelocationHolder | |
36 // A ValueObj type which acts as a union holding a Relocation object. | |
37 // Represents a relocation spec passed into a CodeBuffer during assembly. | |
38 // RelocIterator | |
39 // A StackObj which iterates over the relocations associated with | |
40 // a range of code addresses. Can be used to operate a copy of code. | |
41 // PatchingRelocIterator | |
42 // Specialized subtype of RelocIterator which removes breakpoints | |
43 // temporarily during iteration, then restores them. | |
44 // BoundRelocation | |
45 // An _internal_ type shared by packers and unpackers of relocations. | |
46 // It pastes together a RelocationHolder with some pointers into | |
47 // code and relocInfo streams. | |
48 | |
49 | |
50 // Notes on relocType: | |
51 // | |
52 // These hold enough information to read or write a value embedded in | |
53 // the instructions of an CodeBlob. They're used to update: | |
54 // | |
55 // 1) embedded oops (isOop() == true) | |
56 // 2) inline caches (isIC() == true) | |
57 // 3) runtime calls (isRuntimeCall() == true) | |
58 // 4) internal word ref (isInternalWord() == true) | |
59 // 5) external word ref (isExternalWord() == true) | |
60 // | |
61 // when objects move (GC) or if code moves (compacting the code heap). | |
62 // They are also used to patch the code (if a call site must change) | |
63 // | |
64 // A relocInfo is represented in 16 bits: | |
65 // 4 bits indicating the relocation type | |
66 // 12 bits indicating the offset from the previous relocInfo address | |
67 // | |
68 // The offsets accumulate along the relocInfo stream to encode the | |
69 // address within the CodeBlob, which is named RelocIterator::addr(). | |
70 // The address of a particular relocInfo always points to the first | |
71 // byte of the relevant instruction (and not to any of its subfields | |
72 // or embedded immediate constants). | |
73 // | |
74 // The offset value is scaled appropriately for the target machine. | |
75 // (See relocInfo_<arch>.hpp for the offset scaling.) | |
76 // | |
77 // On some machines, there may also be a "format" field which may provide | |
78 // additional information about the format of the instruction stream | |
79 // at the corresponding code address. The format value is usually zero. | |
80 // Any machine (such as Intel) whose instructions can sometimes contain | |
81 // more than one relocatable constant needs format codes to distinguish | |
82 // which operand goes with a given relocation. | |
83 // | |
84 // If the target machine needs N format bits, the offset has 12-N bits, | |
85 // the format is encoded between the offset and the type, and the | |
86 // relocInfo_<arch>.hpp file has manifest constants for the format codes. | |
87 // | |
88 // If the type is "data_prefix_tag" then the offset bits are further encoded, | |
89 // and in fact represent not a code-stream offset but some inline data. | |
90 // The data takes the form of a counted sequence of halfwords, which | |
91 // precedes the actual relocation record. (Clients never see it directly.) | |
92 // The interpetation of this extra data depends on the relocation type. | |
93 // | |
94 // On machines that have 32-bit immediate fields, there is usually | |
95 // little need for relocation "prefix" data, because the instruction stream | |
96 // is a perfectly reasonable place to store the value. On machines in | |
97 // which 32-bit values must be "split" across instructions, the relocation | |
98 // data is the "true" specification of the value, which is then applied | |
99 // to some field of the instruction (22 or 13 bits, on SPARC). | |
100 // | |
101 // Whenever the location of the CodeBlob changes, any PC-relative | |
102 // relocations, and any internal_word_type relocations, must be reapplied. | |
103 // After the GC runs, oop_type relocations must be reapplied. | |
104 // | |
105 // | |
106 // Here are meanings of the types: | |
107 // | |
108 // relocInfo::none -- a filler record | |
109 // Value: none | |
110 // Instruction: The corresponding code address is ignored | |
111 // Data: Any data prefix and format code are ignored | |
112 // (This means that any relocInfo can be disabled by setting | |
113 // its type to none. See relocInfo::remove.) | |
114 // | |
115 // relocInfo::oop_type -- a reference to an oop | |
116 // Value: an oop, or else the address (handle) of an oop | |
117 // Instruction types: memory (load), set (load address) | |
118 // Data: [] an oop stored in 4 bytes of instruction | |
119 // [n] n is the index of an oop in the CodeBlob's oop pool | |
120 // [[N]n l] and l is a byte offset to be applied to the oop | |
121 // [Nn Ll] both index and offset may be 32 bits if necessary | |
122 // Here is a special hack, used only by the old compiler: | |
123 // [[N]n 00] the value is the __address__ of the nth oop in the pool | |
124 // (Note that the offset allows optimal references to class variables.) | |
125 // | |
126 // relocInfo::internal_word_type -- an address within the same CodeBlob | |
127 // relocInfo::section_word_type -- same, but can refer to another section | |
128 // Value: an address in the CodeBlob's code or constants section | |
129 // Instruction types: memory (load), set (load address) | |
130 // Data: [] stored in 4 bytes of instruction | |
131 // [[L]l] a relative offset (see [About Offsets] below) | |
132 // In the case of section_word_type, the offset is relative to a section | |
133 // base address, and the section number (e.g., SECT_INSTS) is encoded | |
134 // into the low two bits of the offset L. | |
135 // | |
136 // relocInfo::external_word_type -- a fixed address in the runtime system | |
137 // Value: an address | |
138 // Instruction types: memory (load), set (load address) | |
139 // Data: [] stored in 4 bytes of instruction | |
140 // [n] the index of a "well-known" stub (usual case on RISC) | |
141 // [Ll] a 32-bit address | |
142 // | |
143 // relocInfo::runtime_call_type -- a fixed subroutine in the runtime system | |
144 // Value: an address | |
145 // Instruction types: PC-relative call (or a PC-relative branch) | |
146 // Data: [] stored in 4 bytes of instruction | |
147 // | |
148 // relocInfo::static_call_type -- a static call | |
149 // Value: an CodeBlob, a stub, or a fixup routine | |
150 // Instruction types: a call | |
151 // Data: [] | |
152 // The identity of the callee is extracted from debugging information. | |
153 // //%note reloc_3 | |
154 // | |
155 // relocInfo::virtual_call_type -- a virtual call site (which includes an inline | |
156 // cache) | |
157 // Value: an CodeBlob, a stub, the interpreter, or a fixup routine | |
158 // Instruction types: a call, plus some associated set-oop instructions | |
159 // Data: [] the associated set-oops are adjacent to the call | |
160 // [n] n is a relative offset to the first set-oop | |
161 // [[N]n l] and l is a limit within which the set-oops occur | |
162 // [Nn Ll] both n and l may be 32 bits if necessary | |
163 // The identity of the callee is extracted from debugging information. | |
164 // | |
165 // relocInfo::opt_virtual_call_type -- a virtual call site that is statically bound | |
166 // | |
167 // Same info as a static_call_type. We use a special type, so the handling of | |
168 // virtuals and statics are separated. | |
169 // | |
170 // | |
171 // The offset n points to the first set-oop. (See [About Offsets] below.) | |
172 // In turn, the set-oop instruction specifies or contains an oop cell devoted | |
173 // exclusively to the IC call, which can be patched along with the call. | |
174 // | |
175 // The locations of any other set-oops are found by searching the relocation | |
176 // information starting at the first set-oop, and continuing until all | |
177 // relocations up through l have been inspected. The value l is another | |
178 // relative offset. (Both n and l are relative to the call's first byte.) | |
179 // | |
180 // The limit l of the search is exclusive. However, if it points within | |
181 // the call (e.g., offset zero), it is adjusted to point after the call and | |
182 // any associated machine-specific delay slot. | |
183 // | |
184 // Since the offsets could be as wide as 32-bits, these conventions | |
185 // put no restrictions whatever upon code reorganization. | |
186 // | |
187 // The compiler is responsible for ensuring that transition from a clean | |
188 // state to a monomorphic compiled state is MP-safe. This implies that | |
189 // the system must respond well to intermediate states where a random | |
190 // subset of the set-oops has been correctly from the clean state | |
191 // upon entry to the VEP of the compiled method. In the case of a | |
192 // machine (Intel) with a single set-oop instruction, the 32-bit | |
193 // immediate field must not straddle a unit of memory coherence. | |
194 // //%note reloc_3 | |
195 // | |
196 // relocInfo::breakpoint_type -- a conditional breakpoint in the code | |
197 // Value: none | |
198 // Instruction types: any whatsoever | |
199 // Data: [b [T]t i...] | |
200 // The b is a bit-packed word representing the breakpoint's attributes. | |
201 // The t is a target address which the breakpoint calls (when it is enabled). | |
202 // The i... is a place to store one or two instruction words overwritten | |
203 // by a trap, so that the breakpoint may be subsequently removed. | |
204 // | |
205 // relocInfo::static_stub_type -- an extra stub for each static_call_type | |
206 // Value: none | |
207 // Instruction types: a virtual call: { set_oop; jump; } | |
208 // Data: [[N]n] the offset of the associated static_call reloc | |
209 // This stub becomes the target of a static call which must be upgraded | |
210 // to a virtual call (because the callee is interpreted). | |
211 // See [About Offsets] below. | |
212 // //%note reloc_2 | |
213 // | |
214 // For example: | |
215 // | |
216 // INSTRUCTIONS RELOC: TYPE PREFIX DATA | |
217 // ------------ ---- ----------- | |
218 // sethi %hi(myObject), R oop_type [n(myObject)] | |
219 // ld [R+%lo(myObject)+fldOffset], R2 oop_type [n(myObject) fldOffset] | |
220 // add R2, 1, R2 | |
221 // st R2, [R+%lo(myObject)+fldOffset] oop_type [n(myObject) fldOffset] | |
222 //%note reloc_1 | |
223 // | |
224 // This uses 4 instruction words, 8 relocation halfwords, | |
225 // and an entry (which is sharable) in the CodeBlob's oop pool, | |
226 // for a total of 36 bytes. | |
227 // | |
228 // Note that the compiler is responsible for ensuring the "fldOffset" when | |
229 // added to "%lo(myObject)" does not overflow the immediate fields of the | |
230 // memory instructions. | |
231 // | |
232 // | |
233 // [About Offsets] Relative offsets are supplied to this module as | |
234 // positive byte offsets, but they may be internally stored scaled | |
235 // and/or negated, depending on what is most compact for the target | |
236 // system. Since the object pointed to by the offset typically | |
237 // precedes the relocation address, it is profitable to store | |
238 // these negative offsets as positive numbers, but this decision | |
239 // is internal to the relocation information abstractions. | |
240 // | |
241 | |
242 class Relocation; | |
243 class CodeBuffer; | |
244 class CodeSection; | |
245 class RelocIterator; | |
246 | |
247 class relocInfo VALUE_OBJ_CLASS_SPEC { | |
248 friend class RelocIterator; | |
249 public: | |
250 enum relocType { | |
251 none = 0, // Used when no relocation should be generated | |
252 oop_type = 1, // embedded oop | |
253 virtual_call_type = 2, // a standard inline cache call for a virtual send | |
254 opt_virtual_call_type = 3, // a virtual call that has been statically bound (i.e., no IC cache) | |
255 static_call_type = 4, // a static send | |
256 static_stub_type = 5, // stub-entry for static send (takes care of interpreter case) | |
257 runtime_call_type = 6, // call to fixed external routine | |
258 external_word_type = 7, // reference to fixed external address | |
259 internal_word_type = 8, // reference within the current code blob | |
260 section_word_type = 9, // internal, but a cross-section reference | |
261 poll_type = 10, // polling instruction for safepoints | |
262 poll_return_type = 11, // polling instruction for safepoints at return | |
263 breakpoint_type = 12, // an initialization barrier or safepoint | |
264 yet_unused_type = 13, // Still unused | |
265 yet_unused_type_2 = 14, // Still unused | |
266 data_prefix_tag = 15, // tag for a prefix (carries data arguments) | |
267 type_mask = 15 // A mask which selects only the above values | |
268 }; | |
269 | |
270 protected: | |
271 unsigned short _value; | |
272 | |
273 enum RawBitsToken { RAW_BITS }; | |
274 relocInfo(relocType type, RawBitsToken ignore, int bits) | |
275 : _value((type << nontype_width) + bits) { } | |
276 | |
277 relocInfo(relocType type, RawBitsToken ignore, int off, int f) | |
278 : _value((type << nontype_width) + (off / (unsigned)offset_unit) + (f << offset_width)) { } | |
279 | |
280 public: | |
281 // constructor | |
282 relocInfo(relocType type, int offset, int format = 0) | |
283 #ifndef ASSERT | |
284 { | |
285 (*this) = relocInfo(type, RAW_BITS, offset, format); | |
286 } | |
287 #else | |
288 // Put a bunch of assertions out-of-line. | |
289 ; | |
290 #endif | |
291 | |
292 #define APPLY_TO_RELOCATIONS(visitor) \ | |
293 visitor(oop) \ | |
294 visitor(virtual_call) \ | |
295 visitor(opt_virtual_call) \ | |
296 visitor(static_call) \ | |
297 visitor(static_stub) \ | |
298 visitor(runtime_call) \ | |
299 visitor(external_word) \ | |
300 visitor(internal_word) \ | |
301 visitor(poll) \ | |
302 visitor(poll_return) \ | |
303 visitor(breakpoint) \ | |
304 visitor(section_word) \ | |
305 | |
306 | |
307 public: | |
308 enum { | |
309 value_width = sizeof(unsigned short) * BitsPerByte, | |
310 type_width = 4, // == log2(type_mask+1) | |
311 nontype_width = value_width - type_width, | |
312 datalen_width = nontype_width-1, | |
313 datalen_tag = 1 << datalen_width, // or-ed into _value | |
314 datalen_limit = 1 << datalen_width, | |
315 datalen_mask = (1 << datalen_width)-1 | |
316 }; | |
317 | |
318 // accessors | |
319 public: | |
320 relocType type() const { return (relocType)((unsigned)_value >> nontype_width); } | |
321 int format() const { return format_mask==0? 0: format_mask & | |
322 ((unsigned)_value >> offset_width); } | |
323 int addr_offset() const { assert(!is_prefix(), "must have offset"); | |
324 return (_value & offset_mask)*offset_unit; } | |
325 | |
326 protected: | |
327 const short* data() const { assert(is_datalen(), "must have data"); | |
328 return (const short*)(this + 1); } | |
329 int datalen() const { assert(is_datalen(), "must have data"); | |
330 return (_value & datalen_mask); } | |
331 int immediate() const { assert(is_immediate(), "must have immed"); | |
332 return (_value & datalen_mask); } | |
333 public: | |
334 static int addr_unit() { return offset_unit; } | |
335 static int offset_limit() { return (1 << offset_width) * offset_unit; } | |
336 | |
337 void set_type(relocType type); | |
338 void set_format(int format); | |
339 | |
340 void remove() { set_type(none); } | |
341 | |
342 protected: | |
343 bool is_none() const { return type() == none; } | |
344 bool is_prefix() const { return type() == data_prefix_tag; } | |
345 bool is_datalen() const { assert(is_prefix(), "must be prefix"); | |
346 return (_value & datalen_tag) != 0; } | |
347 bool is_immediate() const { assert(is_prefix(), "must be prefix"); | |
348 return (_value & datalen_tag) == 0; } | |
349 | |
350 public: | |
351 // Occasionally records of type relocInfo::none will appear in the stream. | |
352 // We do not bother to filter these out, but clients should ignore them. | |
353 // These records serve as "filler" in three ways: | |
354 // - to skip large spans of unrelocated code (this is rare) | |
355 // - to pad out the relocInfo array to the required oop alignment | |
356 // - to disable old relocation information which is no longer applicable | |
357 | |
358 inline friend relocInfo filler_relocInfo(); | |
359 | |
360 // Every non-prefix relocation may be preceded by at most one prefix, | |
361 // which supplies 1 or more halfwords of associated data. Conventionally, | |
362 // an int is represented by 0, 1, or 2 halfwords, depending on how | |
363 // many bits are required to represent the value. (In addition, | |
364 // if the sole halfword is a 10-bit unsigned number, it is made | |
365 // "immediate" in the prefix header word itself. This optimization | |
366 // is invisible outside this module.) | |
367 | |
368 inline friend relocInfo prefix_relocInfo(int datalen = 0); | |
369 | |
370 protected: | |
371 // an immediate relocInfo optimizes a prefix with one 10-bit unsigned value | |
372 static relocInfo immediate_relocInfo(int data0) { | |
373 assert(fits_into_immediate(data0), "data0 in limits"); | |
374 return relocInfo(relocInfo::data_prefix_tag, RAW_BITS, data0); | |
375 } | |
376 static bool fits_into_immediate(int data0) { | |
377 return (data0 >= 0 && data0 < datalen_limit); | |
378 } | |
379 | |
380 public: | |
381 // Support routines for compilers. | |
382 | |
383 // This routine takes an infant relocInfo (unprefixed) and | |
384 // edits in its prefix, if any. It also updates dest.locs_end. | |
385 void initialize(CodeSection* dest, Relocation* reloc); | |
386 | |
387 // This routine updates a prefix and returns the limit pointer. | |
388 // It tries to compress the prefix from 32 to 16 bits, and if | |
389 // successful returns a reduced "prefix_limit" pointer. | |
390 relocInfo* finish_prefix(short* prefix_limit); | |
391 | |
392 // bit-packers for the data array: | |
393 | |
394 // As it happens, the bytes within the shorts are ordered natively, | |
395 // but the shorts within the word are ordered big-endian. | |
396 // This is an arbitrary choice, made this way mainly to ease debugging. | |
397 static int data0_from_int(jint x) { return x >> value_width; } | |
398 static int data1_from_int(jint x) { return (short)x; } | |
399 static jint jint_from_data(short* data) { | |
400 return (data[0] << value_width) + (unsigned short)data[1]; | |
401 } | |
402 | |
403 static jint short_data_at(int n, short* data, int datalen) { | |
404 return datalen > n ? data[n] : 0; | |
405 } | |
406 | |
407 static jint jint_data_at(int n, short* data, int datalen) { | |
408 return datalen > n+1 ? jint_from_data(&data[n]) : short_data_at(n, data, datalen); | |
409 } | |
410 | |
411 // Update methods for relocation information | |
412 // (since code is dynamically patched, we also need to dynamically update the relocation info) | |
413 // Both methods takes old_type, so it is able to performe sanity checks on the information removed. | |
414 static void change_reloc_info_for_address(RelocIterator *itr, address pc, relocType old_type, relocType new_type); | |
415 static void remove_reloc_info_for_address(RelocIterator *itr, address pc, relocType old_type); | |
416 | |
417 // Machine dependent stuff | |
418 #include "incls/_relocInfo_pd.hpp.incl" | |
419 | |
420 protected: | |
421 // Derived constant, based on format_width which is PD: | |
422 enum { | |
423 offset_width = nontype_width - format_width, | |
424 offset_mask = (1<<offset_width) - 1, | |
425 format_mask = (1<<format_width) - 1 | |
426 }; | |
427 public: | |
428 enum { | |
429 // Conservatively large estimate of maximum length (in shorts) | |
430 // of any relocation record (probably breakpoints are largest). | |
431 // Extended format is length prefix, data words, and tag/offset suffix. | |
432 length_limit = 1 + 1 + (3*BytesPerWord/BytesPerShort) + 1, | |
433 have_format = format_width > 0 | |
434 }; | |
435 }; | |
436 | |
437 #define FORWARD_DECLARE_EACH_CLASS(name) \ | |
438 class name##_Relocation; | |
439 APPLY_TO_RELOCATIONS(FORWARD_DECLARE_EACH_CLASS) | |
440 #undef FORWARD_DECLARE_EACH_CLASS | |
441 | |
442 | |
443 | |
444 inline relocInfo filler_relocInfo() { | |
445 return relocInfo(relocInfo::none, relocInfo::offset_limit() - relocInfo::offset_unit); | |
446 } | |
447 | |
448 inline relocInfo prefix_relocInfo(int datalen) { | |
449 assert(relocInfo::fits_into_immediate(datalen), "datalen in limits"); | |
450 return relocInfo(relocInfo::data_prefix_tag, relocInfo::RAW_BITS, relocInfo::datalen_tag | datalen); | |
451 } | |
452 | |
453 | |
454 // Holder for flyweight relocation objects. | |
455 // Although the flyweight subclasses are of varying sizes, | |
456 // the holder is "one size fits all". | |
457 class RelocationHolder VALUE_OBJ_CLASS_SPEC { | |
458 friend class Relocation; | |
459 friend class CodeSection; | |
460 | |
461 private: | |
462 // this preallocated memory must accommodate all subclasses of Relocation | |
463 // (this number is assertion-checked in Relocation::operator new) | |
464 enum { _relocbuf_size = 5 }; | |
465 void* _relocbuf[ _relocbuf_size ]; | |
466 | |
467 public: | |
468 Relocation* reloc() const { return (Relocation*) &_relocbuf[0]; } | |
469 inline relocInfo::relocType type() const; | |
470 | |
471 // Add a constant offset to a relocation. Helper for class Address. | |
472 RelocationHolder plus(int offset) const; | |
473 | |
474 inline RelocationHolder(); // initializes type to none | |
475 | |
476 inline RelocationHolder(Relocation* r); // make a copy | |
477 | |
478 static const RelocationHolder none; | |
479 }; | |
480 | |
481 // A RelocIterator iterates through the relocation information of a CodeBlob. | |
482 // It is a variable BoundRelocation which is able to take on successive | |
483 // values as it is advanced through a code stream. | |
484 // Usage: | |
485 // RelocIterator iter(nm); | |
486 // while (iter.next()) { | |
487 // iter.reloc()->some_operation(); | |
488 // } | |
489 // or: | |
490 // RelocIterator iter(nm); | |
491 // while (iter.next()) { | |
492 // switch (iter.type()) { | |
493 // case relocInfo::oop_type : | |
494 // case relocInfo::ic_type : | |
495 // case relocInfo::prim_type : | |
496 // case relocInfo::uncommon_type : | |
497 // case relocInfo::runtime_call_type : | |
498 // case relocInfo::internal_word_type: | |
499 // case relocInfo::external_word_type: | |
500 // ... | |
501 // } | |
502 // } | |
503 | |
504 class RelocIterator : public StackObj { | |
505 enum { SECT_CONSTS = 2, | |
506 SECT_LIMIT = 3 }; // must be equal to CodeBuffer::SECT_LIMIT | |
507 friend class Relocation; | |
508 friend class relocInfo; // for change_reloc_info_for_address only | |
509 typedef relocInfo::relocType relocType; | |
510 | |
511 private: | |
512 address _limit; // stop producing relocations after this _addr | |
513 relocInfo* _current; // the current relocation information | |
514 relocInfo* _end; // end marker; we're done iterating when _current == _end | |
515 CodeBlob* _code; // compiled method containing _addr | |
516 address _addr; // instruction to which the relocation applies | |
517 short _databuf; // spare buffer for compressed data | |
518 short* _data; // pointer to the relocation's data | |
519 short _datalen; // number of halfwords in _data | |
520 char _format; // position within the instruction | |
521 | |
522 // Base addresses needed to compute targets of section_word_type relocs. | |
523 address _section_start[SECT_LIMIT]; | |
524 | |
525 void set_has_current(bool b) { | |
526 _datalen = !b ? -1 : 0; | |
527 debug_only(_data = NULL); | |
528 } | |
529 void set_current(relocInfo& ri) { | |
530 _current = &ri; | |
531 set_has_current(true); | |
532 } | |
533 | |
534 RelocationHolder _rh; // where the current relocation is allocated | |
535 | |
536 relocInfo* current() const { assert(has_current(), "must have current"); | |
537 return _current; } | |
538 | |
539 void set_limits(address begin, address limit); | |
540 | |
541 void advance_over_prefix(); // helper method | |
542 | |
543 void initialize_misc() { | |
544 set_has_current(false); | |
545 for (int i = 0; i < SECT_LIMIT; i++) { | |
546 _section_start[i] = NULL; // these will be lazily computed, if needed | |
547 } | |
548 } | |
549 | |
550 address compute_section_start(int n) const; // out-of-line helper | |
551 | |
552 void initialize(CodeBlob* nm, address begin, address limit); | |
553 | |
554 friend class PatchingRelocIterator; | |
555 // make an uninitialized one, for PatchingRelocIterator: | |
556 RelocIterator() { initialize_misc(); } | |
557 | |
558 public: | |
559 // constructor | |
560 RelocIterator(CodeBlob* cb, address begin = NULL, address limit = NULL); | |
561 RelocIterator(CodeSection* cb, address begin = NULL, address limit = NULL); | |
562 | |
563 // get next reloc info, return !eos | |
564 bool next() { | |
565 _current++; | |
566 assert(_current <= _end, "must not overrun relocInfo"); | |
567 if (_current == _end) { | |
568 set_has_current(false); | |
569 return false; | |
570 } | |
571 set_has_current(true); | |
572 | |
573 if (_current->is_prefix()) { | |
574 advance_over_prefix(); | |
575 assert(!current()->is_prefix(), "only one prefix at a time"); | |
576 } | |
577 | |
578 _addr += _current->addr_offset(); | |
579 | |
580 if (_limit != NULL && _addr >= _limit) { | |
581 set_has_current(false); | |
582 return false; | |
583 } | |
584 | |
585 if (relocInfo::have_format) _format = current()->format(); | |
586 return true; | |
587 } | |
588 | |
589 // accessors | |
590 address limit() const { return _limit; } | |
591 void set_limit(address x); | |
592 relocType type() const { return current()->type(); } | |
593 int format() const { return (relocInfo::have_format) ? current()->format() : 0; } | |
594 address addr() const { return _addr; } | |
595 CodeBlob* code() const { return _code; } | |
596 short* data() const { return _data; } | |
597 int datalen() const { return _datalen; } | |
598 bool has_current() const { return _datalen >= 0; } | |
599 | |
600 void set_addr(address addr) { _addr = addr; } | |
601 bool addr_in_const() const { return addr() >= section_start(SECT_CONSTS); } | |
602 | |
603 address section_start(int n) const { | |
604 address res = _section_start[n]; | |
605 return (res != NULL) ? res : compute_section_start(n); | |
606 } | |
607 | |
608 // The address points to the affected displacement part of the instruction. | |
609 // For RISC, this is just the whole instruction. | |
610 // For Intel, this is an unaligned 32-bit word. | |
611 | |
612 // type-specific relocation accessors: oop_Relocation* oop_reloc(), etc. | |
613 #define EACH_TYPE(name) \ | |
614 inline name##_Relocation* name##_reloc(); | |
615 APPLY_TO_RELOCATIONS(EACH_TYPE) | |
616 #undef EACH_TYPE | |
617 // generic relocation accessor; switches on type to call the above | |
618 Relocation* reloc(); | |
619 | |
620 // CodeBlob's have relocation indexes for faster random access: | |
621 static int locs_and_index_size(int code_size, int locs_size); | |
622 // Store an index into [dest_start+dest_count..dest_end). | |
623 // At dest_start[0..dest_count] is the actual relocation information. | |
624 // Everything else up to dest_end is free space for the index. | |
625 static void create_index(relocInfo* dest_begin, int dest_count, relocInfo* dest_end); | |
626 | |
627 #ifndef PRODUCT | |
628 public: | |
629 void print(); | |
630 void print_current(); | |
631 #endif | |
632 }; | |
633 | |
634 | |
635 // A Relocation is a flyweight object allocated within a RelocationHolder. | |
636 // It represents the relocation data of relocation record. | |
637 // So, the RelocIterator unpacks relocInfos into Relocations. | |
638 | |
639 class Relocation VALUE_OBJ_CLASS_SPEC { | |
640 friend class RelocationHolder; | |
641 friend class RelocIterator; | |
642 | |
643 private: | |
644 static void guarantee_size(); | |
645 | |
646 // When a relocation has been created by a RelocIterator, | |
647 // this field is non-null. It allows the relocation to know | |
648 // its context, such as the address to which it applies. | |
649 RelocIterator* _binding; | |
650 | |
651 protected: | |
652 RelocIterator* binding() const { | |
653 assert(_binding != NULL, "must be bound"); | |
654 return _binding; | |
655 } | |
656 void set_binding(RelocIterator* b) { | |
657 assert(_binding == NULL, "must be unbound"); | |
658 _binding = b; | |
659 assert(_binding != NULL, "must now be bound"); | |
660 } | |
661 | |
662 Relocation() { | |
663 _binding = NULL; | |
664 } | |
665 | |
666 static RelocationHolder newHolder() { | |
667 return RelocationHolder(); | |
668 } | |
669 | |
670 public: | |
671 void* operator new(size_t size, const RelocationHolder& holder) { | |
672 if (size > sizeof(holder._relocbuf)) guarantee_size(); | |
673 assert((void* const *)holder.reloc() == &holder._relocbuf[0], "ptrs must agree"); | |
674 return holder.reloc(); | |
675 } | |
676 | |
677 // make a generic relocation for a given type (if possible) | |
678 static RelocationHolder spec_simple(relocInfo::relocType rtype); | |
679 | |
680 // here is the type-specific hook which writes relocation data: | |
681 virtual void pack_data_to(CodeSection* dest) { } | |
682 | |
683 // here is the type-specific hook which reads (unpacks) relocation data: | |
684 virtual void unpack_data() { | |
685 assert(datalen()==0 || type()==relocInfo::none, "no data here"); | |
686 } | |
687 | |
688 protected: | |
689 // Helper functions for pack_data_to() and unpack_data(). | |
690 | |
691 // Most of the compression logic is confined here. | |
692 // (The "immediate data" mechanism of relocInfo works independently | |
693 // of this stuff, and acts to further compress most 1-word data prefixes.) | |
694 | |
695 // A variable-width int is encoded as a short if it will fit in 16 bits. | |
696 // The decoder looks at datalen to decide whether to unpack short or jint. | |
697 // Most relocation records are quite simple, containing at most two ints. | |
698 | |
699 static bool is_short(jint x) { return x == (short)x; } | |
700 static short* add_short(short* p, int x) { *p++ = x; return p; } | |
701 static short* add_jint (short* p, jint x) { | |
702 *p++ = relocInfo::data0_from_int(x); *p++ = relocInfo::data1_from_int(x); | |
703 return p; | |
704 } | |
705 static short* add_var_int(short* p, jint x) { // add a variable-width int | |
706 if (is_short(x)) p = add_short(p, x); | |
707 else p = add_jint (p, x); | |
708 return p; | |
709 } | |
710 | |
711 static short* pack_1_int_to(short* p, jint x0) { | |
712 // Format is one of: [] [x] [Xx] | |
713 if (x0 != 0) p = add_var_int(p, x0); | |
714 return p; | |
715 } | |
716 int unpack_1_int() { | |
717 assert(datalen() <= 2, "too much data"); | |
718 return relocInfo::jint_data_at(0, data(), datalen()); | |
719 } | |
720 | |
721 // With two ints, the short form is used only if both ints are short. | |
722 short* pack_2_ints_to(short* p, jint x0, jint x1) { | |
723 // Format is one of: [] [x y?] [Xx Y?y] | |
724 if (x0 == 0 && x1 == 0) { | |
725 // no halfwords needed to store zeroes | |
726 } else if (is_short(x0) && is_short(x1)) { | |
727 // 1-2 halfwords needed to store shorts | |
728 p = add_short(p, x0); if (x1!=0) p = add_short(p, x1); | |
729 } else { | |
730 // 3-4 halfwords needed to store jints | |
731 p = add_jint(p, x0); p = add_var_int(p, x1); | |
732 } | |
733 return p; | |
734 } | |
735 void unpack_2_ints(jint& x0, jint& x1) { | |
736 int dlen = datalen(); | |
737 short* dp = data(); | |
738 if (dlen <= 2) { | |
739 x0 = relocInfo::short_data_at(0, dp, dlen); | |
740 x1 = relocInfo::short_data_at(1, dp, dlen); | |
741 } else { | |
742 assert(dlen <= 4, "too much data"); | |
743 x0 = relocInfo::jint_data_at(0, dp, dlen); | |
744 x1 = relocInfo::jint_data_at(2, dp, dlen); | |
745 } | |
746 } | |
747 | |
748 protected: | |
749 // platform-dependent utilities for decoding and patching instructions | |
750 void pd_set_data_value (address x, intptr_t off); // a set or mem-ref | |
751 address pd_call_destination (address orig_addr = NULL); | |
752 void pd_set_call_destination (address x); | |
753 void pd_swap_in_breakpoint (address x, short* instrs, int instrlen); | |
754 void pd_swap_out_breakpoint (address x, short* instrs, int instrlen); | |
755 static int pd_breakpoint_size (); | |
756 | |
757 // this extracts the address of an address in the code stream instead of the reloc data | |
758 address* pd_address_in_code (); | |
759 | |
760 // this extracts an address from the code stream instead of the reloc data | |
761 address pd_get_address_from_code (); | |
762 | |
763 // these convert from byte offsets, to scaled offsets, to addresses | |
764 static jint scaled_offset(address x, address base) { | |
765 int byte_offset = x - base; | |
766 int offset = -byte_offset / relocInfo::addr_unit(); | |
767 assert(address_from_scaled_offset(offset, base) == x, "just checkin'"); | |
768 return offset; | |
769 } | |
770 static jint scaled_offset_null_special(address x, address base) { | |
771 // Some relocations treat offset=0 as meaning NULL. | |
772 // Handle this extra convention carefully. | |
773 if (x == NULL) return 0; | |
774 assert(x != base, "offset must not be zero"); | |
775 return scaled_offset(x, base); | |
776 } | |
777 static address address_from_scaled_offset(jint offset, address base) { | |
778 int byte_offset = -( offset * relocInfo::addr_unit() ); | |
779 return base + byte_offset; | |
780 } | |
781 | |
782 // these convert between indexes and addresses in the runtime system | |
783 static int32_t runtime_address_to_index(address runtime_address); | |
784 static address index_to_runtime_address(int32_t index); | |
785 | |
786 // helpers for mapping between old and new addresses after a move or resize | |
787 address old_addr_for(address newa, const CodeBuffer* src, CodeBuffer* dest); | |
788 address new_addr_for(address olda, const CodeBuffer* src, CodeBuffer* dest); | |
789 void normalize_address(address& addr, const CodeSection* dest, bool allow_other_sections = false); | |
790 | |
791 public: | |
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(); } | |
796 protected: | |
797 short* data() const { return binding()->data(); } | |
798 int datalen() const { return binding()->datalen(); } | |
799 int format() const { return binding()->format(); } | |
800 | |
801 public: | |
802 virtual relocInfo::relocType type() { return relocInfo::none; } | |
803 | |
804 // is it a call instruction? | |
805 virtual bool is_call() { return false; } | |
806 | |
807 // is it a data movement instruction? | |
808 virtual bool is_data() { return false; } | |
809 | |
810 // some relocations can compute their own values | |
811 virtual address value(); | |
812 | |
813 // all relocations are able to reassert their values | |
814 virtual void set_value(address x); | |
815 | |
816 virtual void clear_inline_cache() { } | |
817 | |
818 // This method assumes that all virtual/static (inline) caches are cleared (since for static_call_type and | |
819 // ic_call_type is not always posisition dependent (depending on the state of the cache)). However, this is | |
820 // probably a reasonable assumption, since empty caches simplifies code reloacation. | |
821 virtual void fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest) { } | |
822 | |
823 void print(); | |
824 }; | |
825 | |
826 | |
827 // certain inlines must be deferred until class Relocation is defined: | |
828 | |
829 inline RelocationHolder::RelocationHolder() { | |
830 // initialize the vtbl, just to keep things type-safe | |
831 new(*this) Relocation(); | |
832 } | |
833 | |
834 | |
835 inline RelocationHolder::RelocationHolder(Relocation* r) { | |
836 // wordwise copy from r (ok if it copies garbage after r) | |
837 for (int i = 0; i < _relocbuf_size; i++) { | |
838 _relocbuf[i] = ((void**)r)[i]; | |
839 } | |
840 } | |
841 | |
842 | |
843 relocInfo::relocType RelocationHolder::type() const { | |
844 return reloc()->type(); | |
845 } | |
846 | |
847 // A DataRelocation always points at a memory or load-constant instruction.. | |
848 // It is absolute on most machines, and the constant is split on RISCs. | |
849 // The specific subtypes are oop, external_word, and internal_word. | |
850 // By convention, the "value" does not include a separately reckoned "offset". | |
851 class DataRelocation : public Relocation { | |
852 public: | |
853 bool is_data() { return true; } | |
854 | |
855 // both target and offset must be computed somehow from relocation data | |
856 virtual int offset() { return 0; } | |
857 address value() = 0; | |
858 void set_value(address x) { set_value(x, offset()); } | |
859 void set_value(address x, intptr_t o) { | |
860 if (addr_in_const()) | |
861 *(address*)addr() = x; | |
862 else | |
863 pd_set_data_value(x, o); | |
864 } | |
865 | |
866 // The "o" (displacement) argument is relevant only to split relocations | |
867 // on RISC machines. In some CPUs (SPARC), the set-hi and set-lo ins'ns | |
868 // can encode more than 32 bits between them. This allows compilers to | |
869 // share set-hi instructions between addresses that differ by a small | |
870 // offset (e.g., different static variables in the same class). | |
871 // On such machines, the "x" argument to set_value on all set-lo | |
872 // instructions must be the same as the "x" argument for the | |
873 // corresponding set-hi instructions. The "o" arguments for the | |
874 // set-hi instructions are ignored, and must not affect the high-half | |
875 // immediate constant. The "o" arguments for the set-lo instructions are | |
876 // added into the low-half immediate constant, and must not overflow it. | |
877 }; | |
878 | |
879 // A CallRelocation always points at a call instruction. | |
880 // It is PC-relative on most machines. | |
881 class CallRelocation : public Relocation { | |
882 public: | |
883 bool is_call() { return true; } | |
884 | |
885 address destination() { return pd_call_destination(); } | |
886 void set_destination(address x); // pd_set_call_destination | |
887 | |
888 void fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest); | |
889 address value() { return destination(); } | |
890 void set_value(address x) { set_destination(x); } | |
891 }; | |
892 | |
893 class oop_Relocation : public DataRelocation { | |
894 relocInfo::relocType type() { return relocInfo::oop_type; } | |
895 | |
896 public: | |
897 // encode in one of these formats: [] [n] [n l] [Nn l] [Nn Ll] | |
898 // an oop in the CodeBlob's oop pool | |
899 static RelocationHolder spec(int oop_index, int offset = 0) { | |
900 assert(oop_index > 0, "must be a pool-resident oop"); | |
901 RelocationHolder rh = newHolder(); | |
902 new(rh) oop_Relocation(oop_index, offset); | |
903 return rh; | |
904 } | |
905 // an oop in the instruction stream | |
906 static RelocationHolder spec_for_immediate() { | |
907 const int oop_index = 0; | |
908 const int offset = 0; // if you want an offset, use the oop pool | |
909 RelocationHolder rh = newHolder(); | |
910 new(rh) oop_Relocation(oop_index, offset); | |
911 return rh; | |
912 } | |
913 | |
914 private: | |
915 jint _oop_index; // if > 0, index into CodeBlob::oop_at | |
916 jint _offset; // byte offset to apply to the oop itself | |
917 | |
918 oop_Relocation(int oop_index, int offset) { | |
919 _oop_index = oop_index; _offset = offset; | |
920 } | |
921 | |
922 friend class RelocIterator; | |
923 oop_Relocation() { } | |
924 | |
925 public: | |
926 int oop_index() { return _oop_index; } | |
927 int offset() { return _offset; } | |
928 | |
929 // data is packed in "2_ints" format: [i o] or [Ii Oo] | |
930 void pack_data_to(CodeSection* dest); | |
931 void unpack_data(); | |
932 | |
933 void fix_oop_relocation(); // reasserts oop value | |
934 | |
935 address value() { return (address) *oop_addr(); } | |
936 | |
937 bool oop_is_immediate() { return oop_index() == 0; } | |
938 | |
939 oop* oop_addr(); // addr or &pool[jint_data] | |
940 oop oop_value(); // *oop_addr | |
941 // Note: oop_value transparently converts Universe::non_oop_word to NULL. | |
942 }; | |
943 | |
944 class virtual_call_Relocation : public CallRelocation { | |
945 relocInfo::relocType type() { return relocInfo::virtual_call_type; } | |
946 | |
947 public: | |
948 // "first_oop" points to the first associated set-oop. | |
949 // The oop_limit helps find the last associated set-oop. | |
950 // (See comments at the top of this file.) | |
951 static RelocationHolder spec(address first_oop, address oop_limit = NULL) { | |
952 RelocationHolder rh = newHolder(); | |
953 new(rh) virtual_call_Relocation(first_oop, oop_limit); | |
954 return rh; | |
955 } | |
956 | |
957 virtual_call_Relocation(address first_oop, address oop_limit) { | |
958 _first_oop = first_oop; _oop_limit = oop_limit; | |
959 assert(first_oop != NULL, "first oop address must be specified"); | |
960 } | |
961 | |
962 private: | |
963 address _first_oop; // location of first set-oop instruction | |
964 address _oop_limit; // search limit for set-oop instructions | |
965 | |
966 friend class RelocIterator; | |
967 virtual_call_Relocation() { } | |
968 | |
969 | |
970 public: | |
971 address first_oop(); | |
972 address oop_limit(); | |
973 | |
974 // data is packed as scaled offsets in "2_ints" format: [f l] or [Ff Ll] | |
975 // oop_limit is set to 0 if the limit falls somewhere within the call. | |
976 // When unpacking, a zero oop_limit is taken to refer to the end of the call. | |
977 // (This has the effect of bringing in the call's delay slot on SPARC.) | |
978 void pack_data_to(CodeSection* dest); | |
979 void unpack_data(); | |
980 | |
981 void clear_inline_cache(); | |
982 | |
983 // Figure out where an ic_call is hiding, given a set-oop or call. | |
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. | |
986 // The address of the patchable oop is also deduced. | |
987 // The returned iterator will enumerate over the oops and the ic_call, | |
988 // as well as any other relocations that happen to be in that span of code. | |
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); | |
991 }; | |
992 | |
993 | |
994 class opt_virtual_call_Relocation : public CallRelocation { | |
995 relocInfo::relocType type() { return relocInfo::opt_virtual_call_type; } | |
996 | |
997 public: | |
998 static RelocationHolder spec() { | |
999 RelocationHolder rh = newHolder(); | |
1000 new(rh) opt_virtual_call_Relocation(); | |
1001 return rh; | |
1002 } | |
1003 | |
1004 private: | |
1005 friend class RelocIterator; | |
1006 opt_virtual_call_Relocation() { } | |
1007 | |
1008 public: | |
1009 void clear_inline_cache(); | |
1010 | |
1011 // find the matching static_stub | |
1012 address static_stub(); | |
1013 }; | |
1014 | |
1015 | |
1016 class static_call_Relocation : public CallRelocation { | |
1017 relocInfo::relocType type() { return relocInfo::static_call_type; } | |
1018 | |
1019 public: | |
1020 static RelocationHolder spec() { | |
1021 RelocationHolder rh = newHolder(); | |
1022 new(rh) static_call_Relocation(); | |
1023 return rh; | |
1024 } | |
1025 | |
1026 private: | |
1027 friend class RelocIterator; | |
1028 static_call_Relocation() { } | |
1029 | |
1030 public: | |
1031 void clear_inline_cache(); | |
1032 | |
1033 // find the matching static_stub | |
1034 address static_stub(); | |
1035 }; | |
1036 | |
1037 class static_stub_Relocation : public Relocation { | |
1038 relocInfo::relocType type() { return relocInfo::static_stub_type; } | |
1039 | |
1040 public: | |
1041 static RelocationHolder spec(address static_call) { | |
1042 RelocationHolder rh = newHolder(); | |
1043 new(rh) static_stub_Relocation(static_call); | |
1044 return rh; | |
1045 } | |
1046 | |
1047 private: | |
1048 address _static_call; // location of corresponding static_call | |
1049 | |
1050 static_stub_Relocation(address static_call) { | |
1051 _static_call = static_call; | |
1052 } | |
1053 | |
1054 friend class RelocIterator; | |
1055 static_stub_Relocation() { } | |
1056 | |
1057 public: | |
1058 void clear_inline_cache(); | |
1059 | |
1060 address static_call() { return _static_call; } | |
1061 | |
1062 // data is packed as a scaled offset in "1_int" format: [c] or [Cc] | |
1063 void pack_data_to(CodeSection* dest); | |
1064 void unpack_data(); | |
1065 }; | |
1066 | |
1067 class runtime_call_Relocation : public CallRelocation { | |
1068 relocInfo::relocType type() { return relocInfo::runtime_call_type; } | |
1069 | |
1070 public: | |
1071 static RelocationHolder spec() { | |
1072 RelocationHolder rh = newHolder(); | |
1073 new(rh) runtime_call_Relocation(); | |
1074 return rh; | |
1075 } | |
1076 | |
1077 private: | |
1078 friend class RelocIterator; | |
1079 runtime_call_Relocation() { } | |
1080 | |
1081 public: | |
1082 }; | |
1083 | |
1084 class external_word_Relocation : public DataRelocation { | |
1085 relocInfo::relocType type() { return relocInfo::external_word_type; } | |
1086 | |
1087 public: | |
1088 static RelocationHolder spec(address target) { | |
1089 assert(target != NULL, "must not be null"); | |
1090 RelocationHolder rh = newHolder(); | |
1091 new(rh) external_word_Relocation(target); | |
1092 return rh; | |
1093 } | |
1094 | |
1095 // Use this one where all 32/64 bits of the target live in the code stream. | |
1096 // The target must be an intptr_t, and must be absolute (not relative). | |
1097 static RelocationHolder spec_for_immediate() { | |
1098 RelocationHolder rh = newHolder(); | |
1099 new(rh) external_word_Relocation(NULL); | |
1100 return rh; | |
1101 } | |
1102 | |
1103 private: | |
1104 address _target; // address in runtime | |
1105 | |
1106 external_word_Relocation(address target) { | |
1107 _target = target; | |
1108 } | |
1109 | |
1110 friend class RelocIterator; | |
1111 external_word_Relocation() { } | |
1112 | |
1113 public: | |
1114 // data is packed as a well-known address in "1_int" format: [a] or [Aa] | |
1115 // The function runtime_address_to_index is used to turn full addresses | |
1116 // to short indexes, if they are pre-registered by the stub mechanism. | |
1117 // If the "a" value is 0 (i.e., _target is NULL), the address is stored | |
1118 // in the code stream. See external_word_Relocation::target(). | |
1119 void pack_data_to(CodeSection* dest); | |
1120 void unpack_data(); | |
1121 | |
1122 void fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest); | |
1123 address target(); // if _target==NULL, fetch addr from code stream | |
1124 address value() { return target(); } | |
1125 }; | |
1126 | |
1127 class internal_word_Relocation : public DataRelocation { | |
1128 relocInfo::relocType type() { return relocInfo::internal_word_type; } | |
1129 | |
1130 public: | |
1131 static RelocationHolder spec(address target) { | |
1132 assert(target != NULL, "must not be null"); | |
1133 RelocationHolder rh = newHolder(); | |
1134 new(rh) internal_word_Relocation(target); | |
1135 return rh; | |
1136 } | |
1137 | |
1138 // use this one where all the bits of the target can fit in the code stream: | |
1139 static RelocationHolder spec_for_immediate() { | |
1140 RelocationHolder rh = newHolder(); | |
1141 new(rh) internal_word_Relocation(NULL); | |
1142 return rh; | |
1143 } | |
1144 | |
1145 internal_word_Relocation(address target) { | |
1146 _target = target; | |
1147 _section = -1; // self-relative | |
1148 } | |
1149 | |
1150 protected: | |
1151 address _target; // address in CodeBlob | |
1152 int _section; // section providing base address, if any | |
1153 | |
1154 friend class RelocIterator; | |
1155 internal_word_Relocation() { } | |
1156 | |
1157 // bit-width of LSB field in packed offset, if section >= 0 | |
1158 enum { section_width = 2 }; // must equal CodeBuffer::sect_bits | |
1159 | |
1160 public: | |
1161 // data is packed as a scaled offset in "1_int" format: [o] or [Oo] | |
1162 // If the "o" value is 0 (i.e., _target is NULL), the offset is stored | |
1163 // in the code stream. See internal_word_Relocation::target(). | |
1164 // If _section is not -1, it is appended to the low bits of the offset. | |
1165 void pack_data_to(CodeSection* dest); | |
1166 void unpack_data(); | |
1167 | |
1168 void fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest); | |
1169 address target(); // if _target==NULL, fetch addr from code stream | |
1170 int section() { return _section; } | |
1171 address value() { return target(); } | |
1172 }; | |
1173 | |
1174 class section_word_Relocation : public internal_word_Relocation { | |
1175 relocInfo::relocType type() { return relocInfo::section_word_type; } | |
1176 | |
1177 public: | |
1178 static RelocationHolder spec(address target, int section) { | |
1179 RelocationHolder rh = newHolder(); | |
1180 new(rh) section_word_Relocation(target, section); | |
1181 return rh; | |
1182 } | |
1183 | |
1184 section_word_Relocation(address target, int section) { | |
1185 assert(target != NULL, "must not be null"); | |
1186 assert(section >= 0, "must be a valid section"); | |
1187 _target = target; | |
1188 _section = section; | |
1189 } | |
1190 | |
1191 //void pack_data_to -- inherited | |
1192 void unpack_data(); | |
1193 | |
1194 private: | |
1195 friend class RelocIterator; | |
1196 section_word_Relocation() { } | |
1197 }; | |
1198 | |
1199 | |
1200 class poll_Relocation : public Relocation { | |
1201 bool is_data() { return true; } | |
1202 relocInfo::relocType type() { return relocInfo::poll_type; } | |
1203 }; | |
1204 | |
1205 class poll_return_Relocation : public Relocation { | |
1206 bool is_data() { return true; } | |
1207 relocInfo::relocType type() { return relocInfo::poll_return_type; } | |
1208 }; | |
1209 | |
1210 | |
1211 class breakpoint_Relocation : public Relocation { | |
1212 relocInfo::relocType type() { return relocInfo::breakpoint_type; } | |
1213 | |
1214 enum { | |
1215 // attributes which affect the interpretation of the data: | |
1216 removable_attr = 0x0010, // buffer [i...] allows for undoing the trap | |
1217 internal_attr = 0x0020, // the target is an internal addr (local stub) | |
1218 settable_attr = 0x0040, // the target is settable | |
1219 | |
1220 // states which can change over time: | |
1221 enabled_state = 0x0100, // breakpoint must be active in running code | |
1222 active_state = 0x0200, // breakpoint instruction actually in code | |
1223 | |
1224 kind_mask = 0x000F, // mask for extracting kind | |
1225 high_bit = 0x4000 // extra bit which is always set | |
1226 }; | |
1227 | |
1228 public: | |
1229 enum { | |
1230 // kinds: | |
1231 initialization = 1, | |
1232 safepoint = 2 | |
1233 }; | |
1234 | |
1235 // If target is NULL, 32 bits are reserved for a later set_target(). | |
1236 static RelocationHolder spec(int kind, address target = NULL, bool internal_target = false) { | |
1237 RelocationHolder rh = newHolder(); | |
1238 new(rh) breakpoint_Relocation(kind, target, internal_target); | |
1239 return rh; | |
1240 } | |
1241 | |
1242 private: | |
1243 // We require every bits value to NOT to fit into relocInfo::datalen_width, | |
1244 // because we are going to actually store state in the reloc, and so | |
1245 // cannot allow it to be compressed (and hence copied by the iterator). | |
1246 | |
1247 short _bits; // bit-encoded kind, attrs, & state | |
1248 address _target; | |
1249 | |
1250 breakpoint_Relocation(int kind, address target, bool internal_target); | |
1251 | |
1252 friend class RelocIterator; | |
1253 breakpoint_Relocation() { } | |
1254 | |
1255 short bits() const { return _bits; } | |
1256 short& live_bits() const { return data()[0]; } | |
1257 short* instrs() const { return data() + datalen() - instrlen(); } | |
1258 int instrlen() const { return removable() ? pd_breakpoint_size() : 0; } | |
1259 | |
1260 void set_bits(short x) { | |
1261 assert(live_bits() == _bits, "must be the only mutator of reloc info"); | |
1262 live_bits() = _bits = x; | |
1263 } | |
1264 | |
1265 public: | |
1266 address target() const; | |
1267 void set_target(address x); | |
1268 | |
1269 int kind() const { return bits() & kind_mask; } | |
1270 bool enabled() const { return (bits() & enabled_state) != 0; } | |
1271 bool active() const { return (bits() & active_state) != 0; } | |
1272 bool internal() const { return (bits() & internal_attr) != 0; } | |
1273 bool removable() const { return (bits() & removable_attr) != 0; } | |
1274 bool settable() const { return (bits() & settable_attr) != 0; } | |
1275 | |
1276 void set_enabled(bool b); // to activate, you must also say set_active | |
1277 void set_active(bool b); // actually inserts bpt (must be enabled 1st) | |
1278 | |
1279 // data is packed as 16 bits, followed by the target (1 or 2 words), followed | |
1280 // if necessary by empty storage for saving away original instruction bytes. | |
1281 void pack_data_to(CodeSection* dest); | |
1282 void unpack_data(); | |
1283 | |
1284 // during certain operations, breakpoints must be out of the way: | |
1285 void fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest) { | |
1286 assert(!active(), "cannot perform relocation on enabled breakpoints"); | |
1287 } | |
1288 }; | |
1289 | |
1290 | |
1291 // We know all the xxx_Relocation classes, so now we can define these: | |
1292 #define EACH_CASE(name) \ | |
1293 inline name##_Relocation* RelocIterator::name##_reloc() { \ | |
1294 assert(type() == relocInfo::name##_type, "type must agree"); \ | |
1295 /* The purpose of the placed "new" is to re-use the same */ \ | |
1296 /* stack storage for each new iteration. */ \ | |
1297 name##_Relocation* r = new(_rh) name##_Relocation(); \ | |
1298 r->set_binding(this); \ | |
1299 r->name##_Relocation::unpack_data(); \ | |
1300 return r; \ | |
1301 } | |
1302 APPLY_TO_RELOCATIONS(EACH_CASE); | |
1303 #undef EACH_CASE | |
1304 | |
1305 inline RelocIterator::RelocIterator(CodeBlob* cb, address begin, address limit) { | |
1306 initialize(cb, begin, limit); | |
1307 } | |
1308 | |
1309 // if you are going to patch code, you should use this subclass of | |
1310 // RelocIterator | |
1311 class PatchingRelocIterator : public RelocIterator { | |
1312 private: | |
1313 RelocIterator _init_state; | |
1314 | |
1315 void prepass(); // deactivates all breakpoints | |
1316 void postpass(); // reactivates all enabled breakpoints | |
1317 | |
1318 // do not copy these puppies; it would have unpredictable side effects | |
1319 // these are private and have no bodies defined because they should not be called | |
1320 PatchingRelocIterator(const RelocIterator&); | |
1321 void operator=(const RelocIterator&); | |
1322 | |
1323 public: | |
1324 PatchingRelocIterator(CodeBlob* cb, address begin =NULL, address limit =NULL) | |
1325 : RelocIterator(cb, begin, limit) { prepass(); } | |
1326 | |
1327 ~PatchingRelocIterator() { postpass(); } | |
1328 }; |