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annotate src/share/vm/code/relocInfo.hpp @ 1552:c18cbe5936b8
6941466: Oracle rebranding changes for Hotspot repositories
Summary: Change all the Sun copyrights to Oracle copyright
Reviewed-by: ohair
| author | trims |
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| date | Thu, 27 May 2010 19:08:38 -0700 |
| parents | 9ee9cf798b59 |
| children | e9ff18c4ace7 |
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| 0 | 1 /* |
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2 * Copyright (c) 1997, 2008, Oracle and/or its affiliates. All rights reserved. |
| 0 | 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 * | |
|
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
| 0 | 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; } | |
| 304 | 1203 void fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest); |
| 0 | 1204 }; |
| 1205 | |
| 1206 class poll_return_Relocation : public Relocation { | |
| 1207 bool is_data() { return true; } | |
| 1208 relocInfo::relocType type() { return relocInfo::poll_return_type; } | |
| 304 | 1209 void fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest); |
| 0 | 1210 }; |
| 1211 | |
| 1212 | |
| 1213 class breakpoint_Relocation : public Relocation { | |
| 1214 relocInfo::relocType type() { return relocInfo::breakpoint_type; } | |
| 1215 | |
| 1216 enum { | |
| 1217 // attributes which affect the interpretation of the data: | |
| 1218 removable_attr = 0x0010, // buffer [i...] allows for undoing the trap | |
| 1219 internal_attr = 0x0020, // the target is an internal addr (local stub) | |
| 1220 settable_attr = 0x0040, // the target is settable | |
| 1221 | |
| 1222 // states which can change over time: | |
| 1223 enabled_state = 0x0100, // breakpoint must be active in running code | |
| 1224 active_state = 0x0200, // breakpoint instruction actually in code | |
| 1225 | |
| 1226 kind_mask = 0x000F, // mask for extracting kind | |
| 1227 high_bit = 0x4000 // extra bit which is always set | |
| 1228 }; | |
| 1229 | |
| 1230 public: | |
| 1231 enum { | |
| 1232 // kinds: | |
| 1233 initialization = 1, | |
| 1234 safepoint = 2 | |
| 1235 }; | |
| 1236 | |
| 1237 // If target is NULL, 32 bits are reserved for a later set_target(). | |
| 1238 static RelocationHolder spec(int kind, address target = NULL, bool internal_target = false) { | |
| 1239 RelocationHolder rh = newHolder(); | |
| 1240 new(rh) breakpoint_Relocation(kind, target, internal_target); | |
| 1241 return rh; | |
| 1242 } | |
| 1243 | |
| 1244 private: | |
| 1245 // We require every bits value to NOT to fit into relocInfo::datalen_width, | |
| 1246 // because we are going to actually store state in the reloc, and so | |
| 1247 // cannot allow it to be compressed (and hence copied by the iterator). | |
| 1248 | |
| 1249 short _bits; // bit-encoded kind, attrs, & state | |
| 1250 address _target; | |
| 1251 | |
| 1252 breakpoint_Relocation(int kind, address target, bool internal_target); | |
| 1253 | |
| 1254 friend class RelocIterator; | |
| 1255 breakpoint_Relocation() { } | |
| 1256 | |
| 1257 short bits() const { return _bits; } | |
| 1258 short& live_bits() const { return data()[0]; } | |
| 1259 short* instrs() const { return data() + datalen() - instrlen(); } | |
| 1260 int instrlen() const { return removable() ? pd_breakpoint_size() : 0; } | |
| 1261 | |
| 1262 void set_bits(short x) { | |
| 1263 assert(live_bits() == _bits, "must be the only mutator of reloc info"); | |
| 1264 live_bits() = _bits = x; | |
| 1265 } | |
| 1266 | |
| 1267 public: | |
| 1268 address target() const; | |
| 1269 void set_target(address x); | |
| 1270 | |
| 1271 int kind() const { return bits() & kind_mask; } | |
| 1272 bool enabled() const { return (bits() & enabled_state) != 0; } | |
| 1273 bool active() const { return (bits() & active_state) != 0; } | |
| 1274 bool internal() const { return (bits() & internal_attr) != 0; } | |
| 1275 bool removable() const { return (bits() & removable_attr) != 0; } | |
| 1276 bool settable() const { return (bits() & settable_attr) != 0; } | |
| 1277 | |
| 1278 void set_enabled(bool b); // to activate, you must also say set_active | |
| 1279 void set_active(bool b); // actually inserts bpt (must be enabled 1st) | |
| 1280 | |
| 1281 // data is packed as 16 bits, followed by the target (1 or 2 words), followed | |
| 1282 // if necessary by empty storage for saving away original instruction bytes. | |
| 1283 void pack_data_to(CodeSection* dest); | |
| 1284 void unpack_data(); | |
| 1285 | |
| 1286 // during certain operations, breakpoints must be out of the way: | |
| 1287 void fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest) { | |
| 1288 assert(!active(), "cannot perform relocation on enabled breakpoints"); | |
| 1289 } | |
| 1290 }; | |
| 1291 | |
| 1292 | |
| 1293 // We know all the xxx_Relocation classes, so now we can define these: | |
| 1294 #define EACH_CASE(name) \ | |
| 1295 inline name##_Relocation* RelocIterator::name##_reloc() { \ | |
| 1296 assert(type() == relocInfo::name##_type, "type must agree"); \ | |
| 1297 /* The purpose of the placed "new" is to re-use the same */ \ | |
| 1298 /* stack storage for each new iteration. */ \ | |
| 1299 name##_Relocation* r = new(_rh) name##_Relocation(); \ | |
| 1300 r->set_binding(this); \ | |
| 1301 r->name##_Relocation::unpack_data(); \ | |
| 1302 return r; \ | |
| 1303 } | |
| 1304 APPLY_TO_RELOCATIONS(EACH_CASE); | |
| 1305 #undef EACH_CASE | |
| 1306 | |
| 1307 inline RelocIterator::RelocIterator(CodeBlob* cb, address begin, address limit) { | |
| 1308 initialize(cb, begin, limit); | |
| 1309 } | |
| 1310 | |
| 1311 // if you are going to patch code, you should use this subclass of | |
| 1312 // RelocIterator | |
| 1313 class PatchingRelocIterator : public RelocIterator { | |
| 1314 private: | |
| 1315 RelocIterator _init_state; | |
| 1316 | |
| 1317 void prepass(); // deactivates all breakpoints | |
| 1318 void postpass(); // reactivates all enabled breakpoints | |
| 1319 | |
| 1320 // do not copy these puppies; it would have unpredictable side effects | |
| 1321 // these are private and have no bodies defined because they should not be called | |
| 1322 PatchingRelocIterator(const RelocIterator&); | |
| 1323 void operator=(const RelocIterator&); | |
| 1324 | |
| 1325 public: | |
| 1326 PatchingRelocIterator(CodeBlob* cb, address begin =NULL, address limit =NULL) | |
| 1327 : RelocIterator(cb, begin, limit) { prepass(); } | |
| 1328 | |
| 1329 ~PatchingRelocIterator() { postpass(); } | |
| 1330 }; |