Steve Block | a7e24c1 | 2009-10-30 11:49:00 +0000 | [diff] [blame] | 1 | // Copyright 2006-2009 the V8 project authors. All rights reserved. |
| 2 | // Redistribution and use in source and binary forms, with or without |
| 3 | // modification, are permitted provided that the following conditions are |
| 4 | // met: |
| 5 | // |
| 6 | // * Redistributions of source code must retain the above copyright |
| 7 | // notice, this list of conditions and the following disclaimer. |
| 8 | // * Redistributions in binary form must reproduce the above |
| 9 | // copyright notice, this list of conditions and the following |
| 10 | // disclaimer in the documentation and/or other materials provided |
| 11 | // with the distribution. |
| 12 | // * Neither the name of Google Inc. nor the names of its |
| 13 | // contributors may be used to endorse or promote products derived |
| 14 | // from this software without specific prior written permission. |
| 15 | // |
| 16 | // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 17 | // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 18 | // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 19 | // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| 20 | // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 21 | // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| 22 | // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 23 | // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 24 | // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 25 | // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| 26 | // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 27 | |
| 28 | #ifndef V8_GLOBALS_H_ |
| 29 | #define V8_GLOBALS_H_ |
| 30 | |
| 31 | namespace v8 { |
| 32 | namespace internal { |
| 33 | |
| 34 | // Processor architecture detection. For more info on what's defined, see: |
| 35 | // http://msdn.microsoft.com/en-us/library/b0084kay.aspx |
| 36 | // http://www.agner.org/optimize/calling_conventions.pdf |
| 37 | // or with gcc, run: "echo | gcc -E -dM -" |
| 38 | #if defined(_M_X64) || defined(__x86_64__) |
| 39 | #define V8_HOST_ARCH_X64 1 |
| 40 | #define V8_HOST_ARCH_64_BIT 1 |
| 41 | #define V8_HOST_CAN_READ_UNALIGNED 1 |
| 42 | #elif defined(_M_IX86) || defined(__i386__) |
| 43 | #define V8_HOST_ARCH_IA32 1 |
| 44 | #define V8_HOST_ARCH_32_BIT 1 |
| 45 | #define V8_HOST_CAN_READ_UNALIGNED 1 |
| 46 | #elif defined(__ARMEL__) |
| 47 | #define V8_HOST_ARCH_ARM 1 |
| 48 | #define V8_HOST_ARCH_32_BIT 1 |
| 49 | #else |
| 50 | #error Your host architecture was not detected as supported by v8 |
| 51 | #endif |
| 52 | |
| 53 | #if defined(V8_TARGET_ARCH_X64) || defined(V8_TARGET_ARCH_IA32) |
| 54 | #define V8_TARGET_CAN_READ_UNALIGNED 1 |
| 55 | #elif V8_TARGET_ARCH_ARM |
| 56 | #else |
| 57 | #error Your target architecture is not supported by v8 |
| 58 | #endif |
| 59 | |
| 60 | // Support for alternative bool type. This is only enabled if the code is |
| 61 | // compiled with USE_MYBOOL defined. This catches some nasty type bugs. |
| 62 | // For instance, 'bool b = "false";' results in b == true! This is a hidden |
| 63 | // source of bugs. |
| 64 | // However, redefining the bool type does have some negative impact on some |
| 65 | // platforms. It gives rise to compiler warnings (i.e. with |
| 66 | // MSVC) in the API header files when mixing code that uses the standard |
| 67 | // bool with code that uses the redefined version. |
| 68 | // This does not actually belong in the platform code, but needs to be |
| 69 | // defined here because the platform code uses bool, and platform.h is |
| 70 | // include very early in the main include file. |
| 71 | |
| 72 | #ifdef USE_MYBOOL |
| 73 | typedef unsigned int __my_bool__; |
| 74 | #define bool __my_bool__ // use 'indirection' to avoid name clashes |
| 75 | #endif |
| 76 | |
| 77 | typedef uint8_t byte; |
| 78 | typedef byte* Address; |
| 79 | |
| 80 | // Define our own macros for writing 64-bit constants. This is less fragile |
| 81 | // than defining __STDC_CONSTANT_MACROS before including <stdint.h>, and it |
| 82 | // works on compilers that don't have it (like MSVC). |
| 83 | #if V8_HOST_ARCH_64_BIT |
| 84 | #ifdef _MSC_VER |
| 85 | #define V8_UINT64_C(x) (x ## UI64) |
| 86 | #define V8_INT64_C(x) (x ## I64) |
| 87 | #define V8_PTR_PREFIX "ll" |
| 88 | #else // _MSC_VER |
| 89 | #define V8_UINT64_C(x) (x ## UL) |
| 90 | #define V8_INT64_C(x) (x ## L) |
| 91 | #define V8_PTR_PREFIX "l" |
| 92 | #endif // _MSC_VER |
| 93 | #else // V8_HOST_ARCH_64_BIT |
| 94 | #define V8_PTR_PREFIX "" |
| 95 | #endif // V8_HOST_ARCH_64_BIT |
| 96 | |
| 97 | #define V8PRIxPTR V8_PTR_PREFIX "x" |
| 98 | #define V8PRIdPTR V8_PTR_PREFIX "d" |
| 99 | |
| 100 | // Fix for Mac OS X defining uintptr_t as "unsigned long": |
| 101 | #if defined(__APPLE__) && defined(__MACH__) |
| 102 | #undef V8PRIxPTR |
| 103 | #define V8PRIxPTR "lx" |
| 104 | #endif |
| 105 | |
Steve Block | d0582a6 | 2009-12-15 09:54:21 +0000 | [diff] [blame^] | 106 | #if defined(__APPLE__) && defined(__MACH__) |
| 107 | #define USING_MAC_ABI |
| 108 | #endif |
| 109 | |
Steve Block | a7e24c1 | 2009-10-30 11:49:00 +0000 | [diff] [blame] | 110 | // Code-point values in Unicode 4.0 are 21 bits wide. |
| 111 | typedef uint16_t uc16; |
| 112 | typedef int32_t uc32; |
| 113 | |
| 114 | // ----------------------------------------------------------------------------- |
| 115 | // Constants |
| 116 | |
| 117 | const int KB = 1024; |
| 118 | const int MB = KB * KB; |
| 119 | const int GB = KB * KB * KB; |
| 120 | const int kMaxInt = 0x7FFFFFFF; |
| 121 | const int kMinInt = -kMaxInt - 1; |
| 122 | |
| 123 | const uint32_t kMaxUInt32 = 0xFFFFFFFFu; |
| 124 | |
| 125 | const int kCharSize = sizeof(char); // NOLINT |
| 126 | const int kShortSize = sizeof(short); // NOLINT |
| 127 | const int kIntSize = sizeof(int); // NOLINT |
| 128 | const int kDoubleSize = sizeof(double); // NOLINT |
| 129 | const int kPointerSize = sizeof(void*); // NOLINT |
| 130 | const int kIntptrSize = sizeof(intptr_t); // NOLINT |
| 131 | |
| 132 | #if V8_HOST_ARCH_64_BIT |
| 133 | const int kPointerSizeLog2 = 3; |
| 134 | const intptr_t kIntptrSignBit = V8_INT64_C(0x8000000000000000); |
| 135 | #else |
| 136 | const int kPointerSizeLog2 = 2; |
| 137 | const intptr_t kIntptrSignBit = 0x80000000; |
| 138 | #endif |
| 139 | |
| 140 | const int kObjectAlignmentBits = kPointerSizeLog2; |
| 141 | const intptr_t kObjectAlignment = 1 << kObjectAlignmentBits; |
| 142 | const intptr_t kObjectAlignmentMask = kObjectAlignment - 1; |
| 143 | |
| 144 | // Desired alignment for pointers. |
| 145 | const intptr_t kPointerAlignment = (1 << kPointerSizeLog2); |
| 146 | const intptr_t kPointerAlignmentMask = kPointerAlignment - 1; |
| 147 | |
| 148 | |
| 149 | // Tag information for Failure. |
| 150 | const int kFailureTag = 3; |
| 151 | const int kFailureTagSize = 2; |
| 152 | const intptr_t kFailureTagMask = (1 << kFailureTagSize) - 1; |
| 153 | |
| 154 | |
| 155 | const int kBitsPerByte = 8; |
| 156 | const int kBitsPerByteLog2 = 3; |
| 157 | const int kBitsPerPointer = kPointerSize * kBitsPerByte; |
| 158 | const int kBitsPerInt = kIntSize * kBitsPerByte; |
| 159 | |
| 160 | |
| 161 | // Zap-value: The value used for zapping dead objects. |
| 162 | // Should be a recognizable hex value tagged as a heap object pointer. |
| 163 | #ifdef V8_HOST_ARCH_64_BIT |
| 164 | const Address kZapValue = |
| 165 | reinterpret_cast<Address>(V8_UINT64_C(0xdeadbeedbeadbeed)); |
| 166 | const Address kHandleZapValue = |
| 167 | reinterpret_cast<Address>(V8_UINT64_C(0x1baddead0baddead)); |
| 168 | const Address kFromSpaceZapValue = |
| 169 | reinterpret_cast<Address>(V8_UINT64_C(0x1beefdad0beefdad)); |
| 170 | #else |
| 171 | const Address kZapValue = reinterpret_cast<Address>(0xdeadbeed); |
| 172 | const Address kHandleZapValue = reinterpret_cast<Address>(0xbaddead); |
| 173 | const Address kFromSpaceZapValue = reinterpret_cast<Address>(0xbeefdad); |
| 174 | #endif |
| 175 | |
| 176 | |
Steve Block | d0582a6 | 2009-12-15 09:54:21 +0000 | [diff] [blame^] | 177 | // Constants relevant to double precision floating point numbers. |
| 178 | |
| 179 | // Quiet NaNs have bits 51 to 62 set, possibly the sign bit, and no |
| 180 | // other bits set. |
| 181 | const uint64_t kQuietNaNMask = static_cast<uint64_t>(0xfff) << 51; |
| 182 | // If looking only at the top 32 bits, the QNaN mask is bits 19 to 30. |
| 183 | const uint32_t kQuietNaNHighBitsMask = 0xfff << (51 - 32); |
| 184 | |
| 185 | |
Steve Block | a7e24c1 | 2009-10-30 11:49:00 +0000 | [diff] [blame] | 186 | // ----------------------------------------------------------------------------- |
| 187 | // Forward declarations for frequently used classes |
| 188 | // (sorted alphabetically) |
| 189 | |
| 190 | class AccessorInfo; |
| 191 | class Allocation; |
| 192 | class Arguments; |
| 193 | class Assembler; |
| 194 | class BreakableStatement; |
| 195 | class Code; |
| 196 | class CodeGenerator; |
| 197 | class CodeStub; |
| 198 | class Context; |
| 199 | class Debug; |
| 200 | class Debugger; |
| 201 | class DebugInfo; |
| 202 | class Descriptor; |
| 203 | class DescriptorArray; |
| 204 | class Expression; |
| 205 | class ExternalReference; |
| 206 | class FixedArray; |
| 207 | class FunctionEntry; |
| 208 | class FunctionLiteral; |
| 209 | class FunctionTemplateInfo; |
| 210 | class NumberDictionary; |
| 211 | class StringDictionary; |
| 212 | class FreeStoreAllocationPolicy; |
| 213 | template <typename T> class Handle; |
| 214 | class Heap; |
| 215 | class HeapObject; |
| 216 | class IC; |
| 217 | class InterceptorInfo; |
| 218 | class IterationStatement; |
| 219 | class Array; |
| 220 | class JSArray; |
| 221 | class JSFunction; |
| 222 | class JSObject; |
| 223 | class LargeObjectSpace; |
| 224 | template <typename T, class P = FreeStoreAllocationPolicy> class List; |
| 225 | class LookupResult; |
| 226 | class MacroAssembler; |
| 227 | class Map; |
| 228 | class MapSpace; |
| 229 | class MarkCompactCollector; |
| 230 | class NewSpace; |
| 231 | class NodeVisitor; |
| 232 | class Object; |
| 233 | class OldSpace; |
| 234 | class Property; |
| 235 | class Proxy; |
| 236 | class RegExpNode; |
| 237 | struct RegExpCompileData; |
| 238 | class RegExpTree; |
| 239 | class RegExpCompiler; |
| 240 | class RegExpVisitor; |
| 241 | class Scope; |
| 242 | template<class Allocator = FreeStoreAllocationPolicy> class ScopeInfo; |
| 243 | class Script; |
| 244 | class Slot; |
| 245 | class Smi; |
| 246 | class Statement; |
| 247 | class String; |
| 248 | class Struct; |
| 249 | class SwitchStatement; |
| 250 | class AstVisitor; |
| 251 | class Variable; |
| 252 | class VariableProxy; |
| 253 | class RelocInfo; |
| 254 | class Deserializer; |
| 255 | class MessageLocation; |
| 256 | class ObjectGroup; |
| 257 | class TickSample; |
| 258 | class VirtualMemory; |
| 259 | class Mutex; |
| 260 | class ZoneScopeInfo; |
| 261 | |
| 262 | typedef bool (*WeakSlotCallback)(Object** pointer); |
| 263 | |
| 264 | // ----------------------------------------------------------------------------- |
| 265 | // Miscellaneous |
| 266 | |
| 267 | // NOTE: SpaceIterator depends on AllocationSpace enumeration values being |
| 268 | // consecutive. |
| 269 | enum AllocationSpace { |
| 270 | NEW_SPACE, // Semispaces collected with copying collector. |
| 271 | OLD_POINTER_SPACE, // May contain pointers to new space. |
| 272 | OLD_DATA_SPACE, // Must not have pointers to new space. |
| 273 | CODE_SPACE, // No pointers to new space, marked executable. |
| 274 | MAP_SPACE, // Only and all map objects. |
| 275 | CELL_SPACE, // Only and all cell objects. |
| 276 | LO_SPACE, // Promoted large objects. |
| 277 | |
| 278 | FIRST_SPACE = NEW_SPACE, |
Steve Block | d0582a6 | 2009-12-15 09:54:21 +0000 | [diff] [blame^] | 279 | LAST_SPACE = LO_SPACE, |
| 280 | FIRST_PAGED_SPACE = OLD_POINTER_SPACE, |
| 281 | LAST_PAGED_SPACE = CELL_SPACE |
Steve Block | a7e24c1 | 2009-10-30 11:49:00 +0000 | [diff] [blame] | 282 | }; |
| 283 | const int kSpaceTagSize = 3; |
| 284 | const int kSpaceTagMask = (1 << kSpaceTagSize) - 1; |
| 285 | |
| 286 | |
| 287 | // A flag that indicates whether objects should be pretenured when |
| 288 | // allocated (allocated directly into the old generation) or not |
| 289 | // (allocated in the young generation if the object size and type |
| 290 | // allows). |
| 291 | enum PretenureFlag { NOT_TENURED, TENURED }; |
| 292 | |
| 293 | enum GarbageCollector { SCAVENGER, MARK_COMPACTOR }; |
| 294 | |
| 295 | enum Executability { NOT_EXECUTABLE, EXECUTABLE }; |
| 296 | |
Steve Block | d0582a6 | 2009-12-15 09:54:21 +0000 | [diff] [blame^] | 297 | enum VisitMode { VISIT_ALL, VISIT_ONLY_STRONG }; |
| 298 | |
Steve Block | a7e24c1 | 2009-10-30 11:49:00 +0000 | [diff] [blame] | 299 | |
| 300 | // A CodeDesc describes a buffer holding instructions and relocation |
| 301 | // information. The instructions start at the beginning of the buffer |
| 302 | // and grow forward, the relocation information starts at the end of |
| 303 | // the buffer and grows backward. |
| 304 | // |
| 305 | // |<--------------- buffer_size ---------------->| |
| 306 | // |<-- instr_size -->| |<-- reloc_size -->| |
| 307 | // +==================+========+==================+ |
| 308 | // | instructions | free | reloc info | |
| 309 | // +==================+========+==================+ |
| 310 | // ^ |
| 311 | // | |
| 312 | // buffer |
| 313 | |
| 314 | struct CodeDesc { |
| 315 | byte* buffer; |
| 316 | int buffer_size; |
| 317 | int instr_size; |
| 318 | int reloc_size; |
| 319 | Assembler* origin; |
| 320 | }; |
| 321 | |
| 322 | |
| 323 | // Callback function on object slots, used for iterating heap object slots in |
| 324 | // HeapObjects, global pointers to heap objects, etc. The callback allows the |
| 325 | // callback function to change the value of the slot. |
| 326 | typedef void (*ObjectSlotCallback)(HeapObject** pointer); |
| 327 | |
| 328 | |
| 329 | // Callback function used for iterating objects in heap spaces, |
| 330 | // for example, scanning heap objects. |
| 331 | typedef int (*HeapObjectCallback)(HeapObject* obj); |
| 332 | |
| 333 | |
| 334 | // Callback function used for checking constraints when copying/relocating |
| 335 | // objects. Returns true if an object can be copied/relocated from its |
| 336 | // old_addr to a new_addr. |
| 337 | typedef bool (*ConstraintCallback)(Address new_addr, Address old_addr); |
| 338 | |
| 339 | |
| 340 | // Callback function on inline caches, used for iterating over inline caches |
| 341 | // in compiled code. |
| 342 | typedef void (*InlineCacheCallback)(Code* code, Address ic); |
| 343 | |
| 344 | |
| 345 | // State for inline cache call sites. Aliased as IC::State. |
| 346 | enum InlineCacheState { |
| 347 | // Has never been executed. |
| 348 | UNINITIALIZED, |
| 349 | // Has been executed but monomorhic state has been delayed. |
| 350 | PREMONOMORPHIC, |
| 351 | // Has been executed and only one receiver type has been seen. |
| 352 | MONOMORPHIC, |
| 353 | // Like MONOMORPHIC but check failed due to prototype. |
| 354 | MONOMORPHIC_PROTOTYPE_FAILURE, |
| 355 | // Multiple receiver types have been seen. |
| 356 | MEGAMORPHIC, |
| 357 | // Special states for debug break or step in prepare stubs. |
| 358 | DEBUG_BREAK, |
| 359 | DEBUG_PREPARE_STEP_IN |
| 360 | }; |
| 361 | |
| 362 | |
| 363 | enum InLoopFlag { |
| 364 | NOT_IN_LOOP, |
| 365 | IN_LOOP |
| 366 | }; |
| 367 | |
| 368 | |
| 369 | // Type of properties. |
| 370 | // Order of properties is significant. |
| 371 | // Must fit in the BitField PropertyDetails::TypeField. |
| 372 | // A copy of this is in mirror-delay.js. |
| 373 | enum PropertyType { |
| 374 | NORMAL = 0, // only in slow mode |
| 375 | FIELD = 1, // only in fast mode |
| 376 | CONSTANT_FUNCTION = 2, // only in fast mode |
| 377 | CALLBACKS = 3, |
| 378 | INTERCEPTOR = 4, // only in lookup results, not in descriptors. |
| 379 | MAP_TRANSITION = 5, // only in fast mode |
| 380 | CONSTANT_TRANSITION = 6, // only in fast mode |
| 381 | NULL_DESCRIPTOR = 7, // only in fast mode |
| 382 | // All properties before MAP_TRANSITION are real. |
| 383 | FIRST_PHANTOM_PROPERTY_TYPE = MAP_TRANSITION |
| 384 | }; |
| 385 | |
| 386 | |
| 387 | // Whether to remove map transitions and constant transitions from a |
| 388 | // DescriptorArray. |
| 389 | enum TransitionFlag { |
| 390 | REMOVE_TRANSITIONS, |
| 391 | KEEP_TRANSITIONS |
| 392 | }; |
| 393 | |
| 394 | |
| 395 | // Union used for fast testing of specific double values. |
| 396 | union DoubleRepresentation { |
| 397 | double value; |
| 398 | int64_t bits; |
| 399 | DoubleRepresentation(double x) { value = x; } |
| 400 | }; |
| 401 | |
| 402 | |
| 403 | // AccessorCallback |
| 404 | struct AccessorDescriptor { |
| 405 | Object* (*getter)(Object* object, void* data); |
| 406 | Object* (*setter)(JSObject* object, Object* value, void* data); |
| 407 | void* data; |
| 408 | }; |
| 409 | |
| 410 | |
| 411 | // Logging and profiling. |
| 412 | // A StateTag represents a possible state of the VM. When compiled with |
| 413 | // ENABLE_LOGGING_AND_PROFILING, the logger maintains a stack of these. |
| 414 | // Creating a VMState object enters a state by pushing on the stack, and |
| 415 | // destroying a VMState object leaves a state by popping the current state |
| 416 | // from the stack. |
| 417 | |
| 418 | #define STATE_TAG_LIST(V) \ |
| 419 | V(JS) \ |
| 420 | V(GC) \ |
| 421 | V(COMPILER) \ |
| 422 | V(OTHER) \ |
| 423 | V(EXTERNAL) |
| 424 | |
| 425 | enum StateTag { |
| 426 | #define DEF_STATE_TAG(name) name, |
| 427 | STATE_TAG_LIST(DEF_STATE_TAG) |
| 428 | #undef DEF_STATE_TAG |
| 429 | // Pseudo-types. |
| 430 | state_tag_count |
| 431 | }; |
| 432 | |
| 433 | |
| 434 | // ----------------------------------------------------------------------------- |
| 435 | // Macros |
| 436 | |
| 437 | // Testers for test. |
| 438 | |
| 439 | #define HAS_SMI_TAG(value) \ |
| 440 | ((reinterpret_cast<intptr_t>(value) & kSmiTagMask) == kSmiTag) |
| 441 | |
| 442 | #define HAS_FAILURE_TAG(value) \ |
| 443 | ((reinterpret_cast<intptr_t>(value) & kFailureTagMask) == kFailureTag) |
| 444 | |
| 445 | // OBJECT_SIZE_ALIGN returns the value aligned HeapObject size |
| 446 | #define OBJECT_SIZE_ALIGN(value) \ |
| 447 | (((value) + kObjectAlignmentMask) & ~kObjectAlignmentMask) |
| 448 | |
| 449 | // POINTER_SIZE_ALIGN returns the value aligned as a pointer. |
| 450 | #define POINTER_SIZE_ALIGN(value) \ |
| 451 | (((value) + kPointerAlignmentMask) & ~kPointerAlignmentMask) |
| 452 | |
| 453 | // The expression OFFSET_OF(type, field) computes the byte-offset |
| 454 | // of the specified field relative to the containing type. This |
| 455 | // corresponds to 'offsetof' (in stddef.h), except that it doesn't |
| 456 | // use 0 or NULL, which causes a problem with the compiler warnings |
| 457 | // we have enabled (which is also why 'offsetof' doesn't seem to work). |
| 458 | // Here we simply use the non-zero value 4, which seems to work. |
| 459 | #define OFFSET_OF(type, field) \ |
| 460 | (reinterpret_cast<intptr_t>(&(reinterpret_cast<type*>(4)->field)) - 4) |
| 461 | |
| 462 | |
| 463 | // The expression ARRAY_SIZE(a) is a compile-time constant of type |
| 464 | // size_t which represents the number of elements of the given |
| 465 | // array. You should only use ARRAY_SIZE on statically allocated |
| 466 | // arrays. |
| 467 | #define ARRAY_SIZE(a) \ |
| 468 | ((sizeof(a) / sizeof(*(a))) / \ |
| 469 | static_cast<size_t>(!(sizeof(a) % sizeof(*(a))))) |
| 470 | |
| 471 | |
| 472 | // The USE(x) template is used to silence C++ compiler warnings |
| 473 | // issued for (yet) unused variables (typically parameters). |
| 474 | template <typename T> |
| 475 | static inline void USE(T) { } |
| 476 | |
| 477 | |
| 478 | // FUNCTION_ADDR(f) gets the address of a C function f. |
| 479 | #define FUNCTION_ADDR(f) \ |
| 480 | (reinterpret_cast<v8::internal::Address>(reinterpret_cast<intptr_t>(f))) |
| 481 | |
| 482 | |
| 483 | // FUNCTION_CAST<F>(addr) casts an address into a function |
| 484 | // of type F. Used to invoke generated code from within C. |
| 485 | template <typename F> |
| 486 | F FUNCTION_CAST(Address addr) { |
| 487 | return reinterpret_cast<F>(reinterpret_cast<intptr_t>(addr)); |
| 488 | } |
| 489 | |
| 490 | |
| 491 | // A macro to disallow the evil copy constructor and operator= functions |
| 492 | // This should be used in the private: declarations for a class |
| 493 | #define DISALLOW_COPY_AND_ASSIGN(TypeName) \ |
| 494 | TypeName(const TypeName&); \ |
| 495 | void operator=(const TypeName&) |
| 496 | |
| 497 | |
| 498 | // A macro to disallow all the implicit constructors, namely the |
| 499 | // default constructor, copy constructor and operator= functions. |
| 500 | // |
| 501 | // This should be used in the private: declarations for a class |
| 502 | // that wants to prevent anyone from instantiating it. This is |
| 503 | // especially useful for classes containing only static methods. |
| 504 | #define DISALLOW_IMPLICIT_CONSTRUCTORS(TypeName) \ |
| 505 | TypeName(); \ |
| 506 | DISALLOW_COPY_AND_ASSIGN(TypeName) |
| 507 | |
| 508 | |
| 509 | // Support for tracking C++ memory allocation. Insert TRACK_MEMORY("Fisk") |
| 510 | // inside a C++ class and new and delete will be overloaded so logging is |
| 511 | // performed. |
| 512 | // This file (globals.h) is included before log.h, so we use direct calls to |
| 513 | // the Logger rather than the LOG macro. |
| 514 | #ifdef DEBUG |
| 515 | #define TRACK_MEMORY(name) \ |
| 516 | void* operator new(size_t size) { \ |
| 517 | void* result = ::operator new(size); \ |
| 518 | Logger::NewEvent(name, result, size); \ |
| 519 | return result; \ |
| 520 | } \ |
| 521 | void operator delete(void* object) { \ |
| 522 | Logger::DeleteEvent(name, object); \ |
| 523 | ::operator delete(object); \ |
| 524 | } |
| 525 | #else |
| 526 | #define TRACK_MEMORY(name) |
| 527 | #endif |
| 528 | |
| 529 | // define used for helping GCC to make better inlining. Don't bother for debug |
| 530 | // builds. On GCC 3.4.5 using __attribute__((always_inline)) causes compilation |
| 531 | // errors in debug build. |
| 532 | #if defined(__GNUC__) && !defined(DEBUG) |
| 533 | #if (__GNUC__ >= 4) |
| 534 | #define INLINE(header) inline header __attribute__((always_inline)) |
| 535 | #else |
| 536 | #define INLINE(header) inline __attribute__((always_inline)) header |
| 537 | #endif |
| 538 | #else |
| 539 | #define INLINE(header) inline header |
| 540 | #endif |
| 541 | |
| 542 | // The type-based aliasing rule allows the compiler to assume that pointers of |
| 543 | // different types (for some definition of different) never alias each other. |
| 544 | // Thus the following code does not work: |
| 545 | // |
| 546 | // float f = foo(); |
| 547 | // int fbits = *(int*)(&f); |
| 548 | // |
| 549 | // The compiler 'knows' that the int pointer can't refer to f since the types |
| 550 | // don't match, so the compiler may cache f in a register, leaving random data |
| 551 | // in fbits. Using C++ style casts makes no difference, however a pointer to |
| 552 | // char data is assumed to alias any other pointer. This is the 'memcpy |
| 553 | // exception'. |
| 554 | // |
| 555 | // Bit_cast uses the memcpy exception to move the bits from a variable of one |
| 556 | // type of a variable of another type. Of course the end result is likely to |
| 557 | // be implementation dependent. Most compilers (gcc-4.2 and MSVC 2005) |
| 558 | // will completely optimize bit_cast away. |
| 559 | // |
| 560 | // There is an additional use for bit_cast. |
| 561 | // Recent gccs will warn when they see casts that may result in breakage due to |
| 562 | // the type-based aliasing rule. If you have checked that there is no breakage |
| 563 | // you can use bit_cast to cast one pointer type to another. This confuses gcc |
| 564 | // enough that it can no longer see that you have cast one pointer type to |
| 565 | // another thus avoiding the warning. |
| 566 | template <class Dest, class Source> |
| 567 | inline Dest bit_cast(const Source& source) { |
| 568 | // Compile time assertion: sizeof(Dest) == sizeof(Source) |
| 569 | // A compile error here means your Dest and Source have different sizes. |
| 570 | typedef char VerifySizesAreEqual[sizeof(Dest) == sizeof(Source) ? 1 : -1]; |
| 571 | |
| 572 | Dest dest; |
| 573 | memcpy(&dest, &source, sizeof(dest)); |
| 574 | return dest; |
| 575 | } |
| 576 | |
| 577 | |
Steve Block | d0582a6 | 2009-12-15 09:54:21 +0000 | [diff] [blame^] | 578 | // Feature flags bit positions. They are mostly based on the CPUID spec. |
| 579 | // (We assign CPUID itself to one of the currently reserved bits -- |
| 580 | // feel free to change this if needed.) |
| 581 | enum CpuFeature { SSE3 = 32, // x86 |
| 582 | SSE2 = 26, // x86 |
| 583 | CMOV = 15, // x86 |
| 584 | RDTSC = 4, // x86 |
| 585 | CPUID = 10, // x86 |
| 586 | VFP3 = 1, // ARM |
| 587 | SAHF = 0}; // x86 |
| 588 | |
Steve Block | a7e24c1 | 2009-10-30 11:49:00 +0000 | [diff] [blame] | 589 | } } // namespace v8::internal |
| 590 | |
| 591 | #endif // V8_GLOBALS_H_ |