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1 // Copyright 2012 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 #include "../include/v8stdint.h"
32 
33 // Unfortunately, the INFINITY macro cannot be used with the '-pedantic'
34 // warning flag and certain versions of GCC due to a bug:
35 // http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11931
36 // For now, we use the more involved template-based version from <limits>, but
37 // only when compiling with GCC versions affected by the bug (2.96.x - 4.0.x)
38 #if V8_CC_GNU && V8_GNUC_PREREQ(2, 96, 0) && !V8_GNUC_PREREQ(4, 1, 0)
39 # include <limits>  // NOLINT
40 # define V8_INFINITY std::numeric_limits<double>::infinity()
41 #elif V8_CC_MSVC
42 # define V8_INFINITY HUGE_VAL
43 #else
44 # define V8_INFINITY INFINITY
45 #endif
46 
47 namespace v8 {
48 namespace internal {
49 
50 // Processor architecture detection.  For more info on what's defined, see:
51 //   http://msdn.microsoft.com/en-us/library/b0084kay.aspx
52 //   http://www.agner.org/optimize/calling_conventions.pdf
53 //   or with gcc, run: "echo | gcc -E -dM -"
54 #if defined(_M_X64) || defined(__x86_64__)
55 #if defined(__native_client__)
56 // For Native Client builds of V8, use V8_TARGET_ARCH_ARM, so that V8
57 // generates ARM machine code, together with a portable ARM simulator
58 // compiled for the host architecture in question.
59 //
60 // Since Native Client is ILP-32 on all architectures we use
61 // V8_HOST_ARCH_IA32 on both 32- and 64-bit x86.
62 #define V8_HOST_ARCH_IA32 1
63 #define V8_HOST_ARCH_32_BIT 1
64 #define V8_HOST_CAN_READ_UNALIGNED 1
65 #else
66 #define V8_HOST_ARCH_X64 1
67 #define V8_HOST_ARCH_64_BIT 1
68 #define V8_HOST_CAN_READ_UNALIGNED 1
69 #endif  // __native_client__
70 #elif defined(_M_IX86) || defined(__i386__)
71 #define V8_HOST_ARCH_IA32 1
72 #define V8_HOST_ARCH_32_BIT 1
73 #define V8_HOST_CAN_READ_UNALIGNED 1
74 #elif defined(__ARMEL__)
75 #define V8_HOST_ARCH_ARM 1
76 #define V8_HOST_ARCH_32_BIT 1
77 #elif defined(__MIPSEL__)
78 #define V8_HOST_ARCH_MIPS 1
79 #define V8_HOST_ARCH_32_BIT 1
80 #else
81 #error Host architecture was not detected as supported by v8
82 #endif
83 
84 #if defined(__ARM_ARCH_7A__) || \
85     defined(__ARM_ARCH_7R__) || \
86     defined(__ARM_ARCH_7__)
87 # define CAN_USE_ARMV7_INSTRUCTIONS 1
88 # ifndef CAN_USE_VFP3_INSTRUCTIONS
89 #  define CAN_USE_VFP3_INSTRUCTIONS
90 # endif
91 #endif
92 
93 
94 // Target architecture detection. This may be set externally. If not, detect
95 // in the same way as the host architecture, that is, target the native
96 // environment as presented by the compiler.
97 #if !V8_TARGET_ARCH_X64 && !V8_TARGET_ARCH_IA32 && \
98     !V8_TARGET_ARCH_ARM && !V8_TARGET_ARCH_MIPS
99 #if defined(_M_X64) || defined(__x86_64__)
100 #define V8_TARGET_ARCH_X64 1
101 #elif defined(_M_IX86) || defined(__i386__)
102 #define V8_TARGET_ARCH_IA32 1
103 #elif defined(__ARMEL__)
104 #define V8_TARGET_ARCH_ARM 1
105 #elif defined(__MIPSEL__)
106 #define V8_TARGET_ARCH_MIPS 1
107 #else
108 #error Target architecture was not detected as supported by v8
109 #endif
110 #endif
111 
112 // Check for supported combinations of host and target architectures.
113 #if V8_TARGET_ARCH_IA32 && !V8_HOST_ARCH_IA32
114 #error Target architecture ia32 is only supported on ia32 host
115 #endif
116 #if V8_TARGET_ARCH_X64 && !V8_HOST_ARCH_X64
117 #error Target architecture x64 is only supported on x64 host
118 #endif
119 #if (V8_TARGET_ARCH_ARM && !(V8_HOST_ARCH_IA32 || V8_HOST_ARCH_ARM))
120 #error Target architecture arm is only supported on arm and ia32 host
121 #endif
122 #if (V8_TARGET_ARCH_MIPS && !(V8_HOST_ARCH_IA32 || V8_HOST_ARCH_MIPS))
123 #error Target architecture mips is only supported on mips and ia32 host
124 #endif
125 
126 // Determine whether we are running in a simulated environment.
127 // Setting USE_SIMULATOR explicitly from the build script will force
128 // the use of a simulated environment.
129 #if !defined(USE_SIMULATOR)
130 #if (V8_TARGET_ARCH_ARM && !V8_HOST_ARCH_ARM)
131 #define USE_SIMULATOR 1
132 #endif
133 #if (V8_TARGET_ARCH_MIPS && !V8_HOST_ARCH_MIPS)
134 #define USE_SIMULATOR 1
135 #endif
136 #endif
137 
138 // Determine architecture endiannes (we only support little-endian).
139 #if V8_TARGET_ARCH_IA32
140 #define V8_TARGET_LITTLE_ENDIAN 1
141 #elif V8_TARGET_ARCH_X64
142 #define V8_TARGET_LITTLE_ENDIAN 1
143 #elif V8_TARGET_ARCH_ARM
144 #define V8_TARGET_LITTLE_ENDIAN 1
145 #elif V8_TARGET_ARCH_MIPS
146 #define V8_TARGET_LITTLE_ENDIAN 1
147 #else
148 #error Unknown target architecture endiannes
149 #endif
150 
151 // Support for alternative bool type. This is only enabled if the code is
152 // compiled with USE_MYBOOL defined. This catches some nasty type bugs.
153 // For instance, 'bool b = "false";' results in b == true! This is a hidden
154 // source of bugs.
155 // However, redefining the bool type does have some negative impact on some
156 // platforms. It gives rise to compiler warnings (i.e. with
157 // MSVC) in the API header files when mixing code that uses the standard
158 // bool with code that uses the redefined version.
159 // This does not actually belong in the platform code, but needs to be
160 // defined here because the platform code uses bool, and platform.h is
161 // include very early in the main include file.
162 
163 #ifdef USE_MYBOOL
164 typedef unsigned int __my_bool__;
165 #define bool __my_bool__  // use 'indirection' to avoid name clashes
166 #endif
167 
168 typedef uint8_t byte;
169 typedef byte* Address;
170 
171 // Define our own macros for writing 64-bit constants.  This is less fragile
172 // than defining __STDC_CONSTANT_MACROS before including <stdint.h>, and it
173 // works on compilers that don't have it (like MSVC).
174 #if V8_CC_MSVC
175 # define V8_UINT64_C(x)   (x ## UI64)
176 # define V8_INT64_C(x)    (x ## I64)
177 # if V8_HOST_ARCH_64_BIT
178 #  define V8_INTPTR_C(x)  (x ## I64)
179 #  define V8_PTR_PREFIX   "ll"
180 # else
181 #  define V8_INTPTR_C(x)  (x)
182 #  define V8_PTR_PREFIX   ""
183 # endif  // V8_HOST_ARCH_64_BIT
184 #elif V8_CC_MINGW64
185 # define V8_UINT64_C(x)   (x ## ULL)
186 # define V8_INT64_C(x)    (x ## LL)
187 # define V8_INTPTR_C(x)   (x ## LL)
188 # define V8_PTR_PREFIX    "I64"
189 #elif V8_HOST_ARCH_64_BIT
190 # if V8_OS_MACOSX
191 #  define V8_UINT64_C(x)   (x ## ULL)
192 #  define V8_INT64_C(x)    (x ## LL)
193 # else
194 #  define V8_UINT64_C(x)   (x ## UL)
195 #  define V8_INT64_C(x)    (x ## L)
196 # endif
197 # define V8_INTPTR_C(x)   (x ## L)
198 # define V8_PTR_PREFIX    "l"
199 #else
200 # define V8_UINT64_C(x)   (x ## ULL)
201 # define V8_INT64_C(x)    (x ## LL)
202 # define V8_INTPTR_C(x)   (x)
203 # define V8_PTR_PREFIX    ""
204 #endif
205 
206 // The following macro works on both 32 and 64-bit platforms.
207 // Usage: instead of writing 0x1234567890123456
208 //      write V8_2PART_UINT64_C(0x12345678,90123456);
209 #define V8_2PART_UINT64_C(a, b) (((static_cast<uint64_t>(a) << 32) + 0x##b##u))
210 
211 #define V8PRIxPTR V8_PTR_PREFIX "x"
212 #define V8PRIdPTR V8_PTR_PREFIX "d"
213 #define V8PRIuPTR V8_PTR_PREFIX "u"
214 
215 // Fix for Mac OS X defining uintptr_t as "unsigned long":
216 #if V8_OS_MACOSX
217 #undef V8PRIxPTR
218 #define V8PRIxPTR "lx"
219 #endif
220 
221 #if V8_OS_MACOSX || defined(__FreeBSD__) || defined(__OpenBSD__)
222 #define USING_BSD_ABI
223 #endif
224 
225 // -----------------------------------------------------------------------------
226 // Constants
227 
228 const int KB = 1024;
229 const int MB = KB * KB;
230 const int GB = KB * KB * KB;
231 const int kMaxInt = 0x7FFFFFFF;
232 const int kMinInt = -kMaxInt - 1;
233 const int kMaxInt8 = (1 << 7) - 1;
234 const int kMinInt8 = -(1 << 7);
235 const int kMaxUInt8 = (1 << 8) - 1;
236 const int kMinUInt8 = 0;
237 const int kMaxInt16 = (1 << 15) - 1;
238 const int kMinInt16 = -(1 << 15);
239 const int kMaxUInt16 = (1 << 16) - 1;
240 const int kMinUInt16 = 0;
241 
242 const uint32_t kMaxUInt32 = 0xFFFFFFFFu;
243 
244 const int kCharSize      = sizeof(char);      // NOLINT
245 const int kShortSize     = sizeof(short);     // NOLINT
246 const int kIntSize       = sizeof(int);       // NOLINT
247 const int kInt32Size     = sizeof(int32_t);   // NOLINT
248 const int kInt64Size     = sizeof(int64_t);   // NOLINT
249 const int kDoubleSize    = sizeof(double);    // NOLINT
250 const int kIntptrSize    = sizeof(intptr_t);  // NOLINT
251 const int kPointerSize   = sizeof(void*);     // NOLINT
252 const int kRegisterSize  = kPointerSize;
253 const int kPCOnStackSize = kRegisterSize;
254 const int kFPOnStackSize = kRegisterSize;
255 
256 const int kDoubleSizeLog2 = 3;
257 
258 #if V8_HOST_ARCH_64_BIT
259 const int kPointerSizeLog2 = 3;
260 const intptr_t kIntptrSignBit = V8_INT64_C(0x8000000000000000);
261 const uintptr_t kUintptrAllBitsSet = V8_UINT64_C(0xFFFFFFFFFFFFFFFF);
262 const bool kIs64BitArch = true;
263 #else
264 const int kPointerSizeLog2 = 2;
265 const intptr_t kIntptrSignBit = 0x80000000;
266 const uintptr_t kUintptrAllBitsSet = 0xFFFFFFFFu;
267 const bool kIs64BitArch = false;
268 #endif
269 
270 const int kBitsPerByte = 8;
271 const int kBitsPerByteLog2 = 3;
272 const int kBitsPerPointer = kPointerSize * kBitsPerByte;
273 const int kBitsPerInt = kIntSize * kBitsPerByte;
274 
275 // IEEE 754 single precision floating point number bit layout.
276 const uint32_t kBinary32SignMask = 0x80000000u;
277 const uint32_t kBinary32ExponentMask = 0x7f800000u;
278 const uint32_t kBinary32MantissaMask = 0x007fffffu;
279 const int kBinary32ExponentBias = 127;
280 const int kBinary32MaxExponent  = 0xFE;
281 const int kBinary32MinExponent  = 0x01;
282 const int kBinary32MantissaBits = 23;
283 const int kBinary32ExponentShift = 23;
284 
285 // Quiet NaNs have bits 51 to 62 set, possibly the sign bit, and no
286 // other bits set.
287 const uint64_t kQuietNaNMask = static_cast<uint64_t>(0xfff) << 51;
288 
289 // Latin1/UTF-16 constants
290 // Code-point values in Unicode 4.0 are 21 bits wide.
291 // Code units in UTF-16 are 16 bits wide.
292 typedef uint16_t uc16;
293 typedef int32_t uc32;
294 const int kOneByteSize    = kCharSize;
295 const int kUC16Size     = sizeof(uc16);      // NOLINT
296 
297 
298 // Round up n to be a multiple of sz, where sz is a power of 2.
299 #define ROUND_UP(n, sz) (((n) + ((sz) - 1)) & ~((sz) - 1))
300 
301 
302 // The expression OFFSET_OF(type, field) computes the byte-offset
303 // of the specified field relative to the containing type. This
304 // corresponds to 'offsetof' (in stddef.h), except that it doesn't
305 // use 0 or NULL, which causes a problem with the compiler warnings
306 // we have enabled (which is also why 'offsetof' doesn't seem to work).
307 // Here we simply use the non-zero value 4, which seems to work.
308 #define OFFSET_OF(type, field)                                          \
309   (reinterpret_cast<intptr_t>(&(reinterpret_cast<type*>(4)->field)) - 4)
310 
311 
312 // The expression ARRAY_SIZE(a) is a compile-time constant of type
313 // size_t which represents the number of elements of the given
314 // array. You should only use ARRAY_SIZE on statically allocated
315 // arrays.
316 #define ARRAY_SIZE(a)                                   \
317   ((sizeof(a) / sizeof(*(a))) /                         \
318   static_cast<size_t>(!(sizeof(a) % sizeof(*(a)))))
319 
320 
321 // The USE(x) template is used to silence C++ compiler warnings
322 // issued for (yet) unused variables (typically parameters).
323 template <typename T>
USE(T)324 inline void USE(T) { }
325 
326 
327 // FUNCTION_ADDR(f) gets the address of a C function f.
328 #define FUNCTION_ADDR(f)                                        \
329   (reinterpret_cast<v8::internal::Address>(reinterpret_cast<intptr_t>(f)))
330 
331 
332 // FUNCTION_CAST<F>(addr) casts an address into a function
333 // of type F. Used to invoke generated code from within C.
334 template <typename F>
FUNCTION_CAST(Address addr)335 F FUNCTION_CAST(Address addr) {
336   return reinterpret_cast<F>(reinterpret_cast<intptr_t>(addr));
337 }
338 
339 
340 // A macro to disallow the evil copy constructor and operator= functions
341 // This should be used in the private: declarations for a class
342 #define DISALLOW_COPY_AND_ASSIGN(TypeName)  \
343   TypeName(const TypeName&) V8_DELETE;      \
344   void operator=(const TypeName&) V8_DELETE
345 
346 
347 // A macro to disallow all the implicit constructors, namely the
348 // default constructor, copy constructor and operator= functions.
349 //
350 // This should be used in the private: declarations for a class
351 // that wants to prevent anyone from instantiating it. This is
352 // especially useful for classes containing only static methods.
353 #define DISALLOW_IMPLICIT_CONSTRUCTORS(TypeName)  \
354   TypeName() V8_DELETE;                           \
355   DISALLOW_COPY_AND_ASSIGN(TypeName)
356 
357 
358 // Newly written code should use V8_INLINE and V8_NOINLINE directly.
359 #define INLINE(declarator)    V8_INLINE declarator
360 #define NO_INLINE(declarator) V8_NOINLINE declarator
361 
362 
363 // Newly written code should use V8_WARN_UNUSED_RESULT.
364 #define MUST_USE_RESULT V8_WARN_UNUSED_RESULT
365 
366 
367 // Define DISABLE_ASAN macros.
368 #if defined(__has_feature)
369 #if __has_feature(address_sanitizer)
370 #define DISABLE_ASAN __attribute__((no_sanitize_address))
371 #endif
372 #endif
373 
374 
375 #ifndef DISABLE_ASAN
376 #define DISABLE_ASAN
377 #endif
378 
379 
380 // -----------------------------------------------------------------------------
381 // Forward declarations for frequently used classes
382 // (sorted alphabetically)
383 
384 class FreeStoreAllocationPolicy;
385 template <typename T, class P = FreeStoreAllocationPolicy> class List;
386 
387 // -----------------------------------------------------------------------------
388 // Declarations for use in both the preparser and the rest of V8.
389 
390 // The different language modes that V8 implements. ES5 defines two language
391 // modes: an unrestricted mode respectively a strict mode which are indicated by
392 // CLASSIC_MODE respectively STRICT_MODE in the enum. The harmony spec drafts
393 // for the next ES standard specify a new third mode which is called 'extended
394 // mode'. The extended mode is only available if the harmony flag is set. It is
395 // based on the 'strict mode' and adds new functionality to it. This means that
396 // most of the semantics of these two modes coincide.
397 //
398 // In the current draft the term 'base code' is used to refer to code that is
399 // neither in strict nor extended mode. However, the more distinguishing term
400 // 'classic mode' is used in V8 instead to avoid mix-ups.
401 
402 enum LanguageMode {
403   CLASSIC_MODE,
404   STRICT_MODE,
405   EXTENDED_MODE
406 };
407 
408 
409 // The Strict Mode (ECMA-262 5th edition, 4.2.2).
410 //
411 // This flag is used in the backend to represent the language mode. So far
412 // there is no semantic difference between the strict and the extended mode in
413 // the backend, so both modes are represented by the kStrictMode value.
414 enum StrictModeFlag {
415   kNonStrictMode,
416   kStrictMode
417 };
418 
419 
420 } }  // namespace v8::internal
421 
422 #endif  // V8_GLOBALS_H_
423