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 // Define V8_INFINITY
32 #define V8_INFINITY INFINITY
33
34 // GCC specific stuff
35 #ifdef __GNUC__
36
37 #define __GNUC_VERSION_FOR_INFTY__ (__GNUC__ * 10000 + __GNUC_MINOR__ * 100)
38
39 // Unfortunately, the INFINITY macro cannot be used with the '-pedantic'
40 // warning flag and certain versions of GCC due to a bug:
41 // http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11931
42 // For now, we use the more involved template-based version from <limits>, but
43 // only when compiling with GCC versions affected by the bug (2.96.x - 4.0.x)
44 // __GNUC_PREREQ is not defined in GCC for Mac OS X, so we define our own macro
45 #if __GNUC_VERSION_FOR_INFTY__ >= 29600 && __GNUC_VERSION_FOR_INFTY__ < 40100
46 #include <limits>
47 #undef V8_INFINITY
48 #define V8_INFINITY std::numeric_limits<double>::infinity()
49 #endif
50 #undef __GNUC_VERSION_FOR_INFTY__
51
52 #endif // __GNUC__
53
54 #ifdef _MSC_VER
55 #undef V8_INFINITY
56 #define V8_INFINITY HUGE_VAL
57 #endif
58
59
60 #include "../include/v8stdint.h"
61
62 namespace v8 {
63 namespace internal {
64
65 // Processor architecture detection. For more info on what's defined, see:
66 // http://msdn.microsoft.com/en-us/library/b0084kay.aspx
67 // http://www.agner.org/optimize/calling_conventions.pdf
68 // or with gcc, run: "echo | gcc -E -dM -"
69 #if defined(_M_X64) || defined(__x86_64__)
70 #define V8_HOST_ARCH_X64 1
71 #define V8_HOST_ARCH_64_BIT 1
72 #define V8_HOST_CAN_READ_UNALIGNED 1
73 #elif defined(_M_IX86) || defined(__i386__)
74 #define V8_HOST_ARCH_IA32 1
75 #define V8_HOST_ARCH_32_BIT 1
76 #define V8_HOST_CAN_READ_UNALIGNED 1
77 #elif defined(__ARMEL__)
78 #define V8_HOST_ARCH_ARM 1
79 #define V8_HOST_ARCH_32_BIT 1
80 // Some CPU-OS combinations allow unaligned access on ARM. We assume
81 // that unaligned accesses are not allowed unless the build system
82 // defines the CAN_USE_UNALIGNED_ACCESSES macro to be non-zero.
83 #if CAN_USE_UNALIGNED_ACCESSES
84 #define V8_HOST_CAN_READ_UNALIGNED 1
85 #endif
86 #elif defined(__MIPSEL__)
87 #define V8_HOST_ARCH_MIPS 1
88 #define V8_HOST_ARCH_32_BIT 1
89 #else
90 #error Host architecture was not detected as supported by v8
91 #endif
92
93 // Target architecture detection. This may be set externally. If not, detect
94 // in the same way as the host architecture, that is, target the native
95 // environment as presented by the compiler.
96 #if !defined(V8_TARGET_ARCH_X64) && !defined(V8_TARGET_ARCH_IA32) && \
97 !defined(V8_TARGET_ARCH_ARM) && !defined(V8_TARGET_ARCH_MIPS)
98 #if defined(_M_X64) || defined(__x86_64__)
99 #define V8_TARGET_ARCH_X64 1
100 #elif defined(_M_IX86) || defined(__i386__)
101 #define V8_TARGET_ARCH_IA32 1
102 #elif defined(__ARMEL__)
103 #define V8_TARGET_ARCH_ARM 1
104 #elif defined(__MIPSEL__)
105 #define V8_TARGET_ARCH_MIPS 1
106 #else
107 #error Target architecture was not detected as supported by v8
108 #endif
109 #endif
110
111 // Check for supported combinations of host and target architectures.
112 #if defined(V8_TARGET_ARCH_IA32) && !defined(V8_HOST_ARCH_IA32)
113 #error Target architecture ia32 is only supported on ia32 host
114 #endif
115 #if defined(V8_TARGET_ARCH_X64) && !defined(V8_HOST_ARCH_X64)
116 #error Target architecture x64 is only supported on x64 host
117 #endif
118 #if (defined(V8_TARGET_ARCH_ARM) && \
119 !(defined(V8_HOST_ARCH_IA32) || defined(V8_HOST_ARCH_ARM)))
120 #error Target architecture arm is only supported on arm and ia32 host
121 #endif
122 #if (defined(V8_TARGET_ARCH_MIPS) && \
123 !(defined(V8_HOST_ARCH_IA32) || defined(V8_HOST_ARCH_MIPS)))
124 #error Target architecture mips is only supported on mips and ia32 host
125 #endif
126
127 // Determine whether we are running in a simulated environment.
128 // Setting USE_SIMULATOR explicitly from the build script will force
129 // the use of a simulated environment.
130 #if !defined(USE_SIMULATOR)
131 #if (defined(V8_TARGET_ARCH_ARM) && !defined(V8_HOST_ARCH_ARM))
132 #define USE_SIMULATOR 1
133 #endif
134 #if (defined(V8_TARGET_ARCH_MIPS) && !defined(V8_HOST_ARCH_MIPS))
135 #define USE_SIMULATOR 1
136 #endif
137 #endif
138
139 // Define unaligned read for the target architectures supporting it.
140 #if defined(V8_TARGET_ARCH_X64) || defined(V8_TARGET_ARCH_IA32)
141 #define V8_TARGET_CAN_READ_UNALIGNED 1
142 #elif V8_TARGET_ARCH_ARM
143 // Some CPU-OS combinations allow unaligned access on ARM. We assume
144 // that unaligned accesses are not allowed unless the build system
145 // defines the CAN_USE_UNALIGNED_ACCESSES macro to be non-zero.
146 #if CAN_USE_UNALIGNED_ACCESSES
147 #define V8_TARGET_CAN_READ_UNALIGNED 1
148 #endif
149 #elif V8_TARGET_ARCH_MIPS
150 #else
151 #error Target architecture is not supported by v8
152 #endif
153
154 // Support for alternative bool type. This is only enabled if the code is
155 // compiled with USE_MYBOOL defined. This catches some nasty type bugs.
156 // For instance, 'bool b = "false";' results in b == true! This is a hidden
157 // source of bugs.
158 // However, redefining the bool type does have some negative impact on some
159 // platforms. It gives rise to compiler warnings (i.e. with
160 // MSVC) in the API header files when mixing code that uses the standard
161 // bool with code that uses the redefined version.
162 // This does not actually belong in the platform code, but needs to be
163 // defined here because the platform code uses bool, and platform.h is
164 // include very early in the main include file.
165
166 #ifdef USE_MYBOOL
167 typedef unsigned int __my_bool__;
168 #define bool __my_bool__ // use 'indirection' to avoid name clashes
169 #endif
170
171 typedef uint8_t byte;
172 typedef byte* Address;
173
174 // Define our own macros for writing 64-bit constants. This is less fragile
175 // than defining __STDC_CONSTANT_MACROS before including <stdint.h>, and it
176 // works on compilers that don't have it (like MSVC).
177 #if V8_HOST_ARCH_64_BIT
178 #if defined(_MSC_VER)
179 #define V8_UINT64_C(x) (x ## UI64)
180 #define V8_INT64_C(x) (x ## I64)
181 #define V8_INTPTR_C(x) (x ## I64)
182 #define V8_PTR_PREFIX "ll"
183 #elif defined(__MINGW64__)
184 #define V8_UINT64_C(x) (x ## ULL)
185 #define V8_INT64_C(x) (x ## LL)
186 #define V8_INTPTR_C(x) (x ## LL)
187 #define V8_PTR_PREFIX "I64"
188 #else
189 #define V8_UINT64_C(x) (x ## UL)
190 #define V8_INT64_C(x) (x ## L)
191 #define V8_INTPTR_C(x) (x ## L)
192 #define V8_PTR_PREFIX "l"
193 #endif
194 #else // V8_HOST_ARCH_64_BIT
195 #define V8_INTPTR_C(x) (x)
196 #define V8_PTR_PREFIX ""
197 #endif // V8_HOST_ARCH_64_BIT
198
199 // The following macro works on both 32 and 64-bit platforms.
200 // Usage: instead of writing 0x1234567890123456
201 // write V8_2PART_UINT64_C(0x12345678,90123456);
202 #define V8_2PART_UINT64_C(a, b) (((static_cast<uint64_t>(a) << 32) + 0x##b##u))
203
204 #define V8PRIxPTR V8_PTR_PREFIX "x"
205 #define V8PRIdPTR V8_PTR_PREFIX "d"
206
207 // Fix for Mac OS X defining uintptr_t as "unsigned long":
208 #if defined(__APPLE__) && defined(__MACH__)
209 #undef V8PRIxPTR
210 #define V8PRIxPTR "lx"
211 #endif
212
213 #if (defined(__APPLE__) && defined(__MACH__)) || \
214 defined(__FreeBSD__) || defined(__OpenBSD__)
215 #define USING_BSD_ABI
216 #endif
217
218 // -----------------------------------------------------------------------------
219 // Constants
220
221 const int KB = 1024;
222 const int MB = KB * KB;
223 const int GB = KB * KB * KB;
224 const int kMaxInt = 0x7FFFFFFF;
225 const int kMinInt = -kMaxInt - 1;
226
227 const uint32_t kMaxUInt32 = 0xFFFFFFFFu;
228
229 const int kCharSize = sizeof(char); // NOLINT
230 const int kShortSize = sizeof(short); // NOLINT
231 const int kIntSize = sizeof(int); // NOLINT
232 const int kDoubleSize = sizeof(double); // NOLINT
233 const int kIntptrSize = sizeof(intptr_t); // NOLINT
234 const int kPointerSize = sizeof(void*); // NOLINT
235
236 const int kDoubleSizeLog2 = 3;
237
238 // Size of the state of a the random number generator.
239 const int kRandomStateSize = 2 * kIntSize;
240
241 #if V8_HOST_ARCH_64_BIT
242 const int kPointerSizeLog2 = 3;
243 const intptr_t kIntptrSignBit = V8_INT64_C(0x8000000000000000);
244 const uintptr_t kUintptrAllBitsSet = V8_UINT64_C(0xFFFFFFFFFFFFFFFF);
245 #else
246 const int kPointerSizeLog2 = 2;
247 const intptr_t kIntptrSignBit = 0x80000000;
248 const uintptr_t kUintptrAllBitsSet = 0xFFFFFFFFu;
249 #endif
250
251 const int kBitsPerByte = 8;
252 const int kBitsPerByteLog2 = 3;
253 const int kBitsPerPointer = kPointerSize * kBitsPerByte;
254 const int kBitsPerInt = kIntSize * kBitsPerByte;
255
256 // IEEE 754 single precision floating point number bit layout.
257 const uint32_t kBinary32SignMask = 0x80000000u;
258 const uint32_t kBinary32ExponentMask = 0x7f800000u;
259 const uint32_t kBinary32MantissaMask = 0x007fffffu;
260 const int kBinary32ExponentBias = 127;
261 const int kBinary32MaxExponent = 0xFE;
262 const int kBinary32MinExponent = 0x01;
263 const int kBinary32MantissaBits = 23;
264 const int kBinary32ExponentShift = 23;
265
266 // Quiet NaNs have bits 51 to 62 set, possibly the sign bit, and no
267 // other bits set.
268 const uint64_t kQuietNaNMask = static_cast<uint64_t>(0xfff) << 51;
269
270 // ASCII/UTF-16 constants
271 // Code-point values in Unicode 4.0 are 21 bits wide.
272 // Code units in UTF-16 are 16 bits wide.
273 typedef uint16_t uc16;
274 typedef int32_t uc32;
275 const int kASCIISize = kCharSize;
276 const int kUC16Size = sizeof(uc16); // NOLINT
277 const uc32 kMaxAsciiCharCode = 0x7f;
278 const uint32_t kMaxAsciiCharCodeU = 0x7fu;
279
280
281 // The expression OFFSET_OF(type, field) computes the byte-offset
282 // of the specified field relative to the containing type. This
283 // corresponds to 'offsetof' (in stddef.h), except that it doesn't
284 // use 0 or NULL, which causes a problem with the compiler warnings
285 // we have enabled (which is also why 'offsetof' doesn't seem to work).
286 // Here we simply use the non-zero value 4, which seems to work.
287 #define OFFSET_OF(type, field) \
288 (reinterpret_cast<intptr_t>(&(reinterpret_cast<type*>(4)->field)) - 4)
289
290
291 // The expression ARRAY_SIZE(a) is a compile-time constant of type
292 // size_t which represents the number of elements of the given
293 // array. You should only use ARRAY_SIZE on statically allocated
294 // arrays.
295 #define ARRAY_SIZE(a) \
296 ((sizeof(a) / sizeof(*(a))) / \
297 static_cast<size_t>(!(sizeof(a) % sizeof(*(a)))))
298
299
300 // The USE(x) template is used to silence C++ compiler warnings
301 // issued for (yet) unused variables (typically parameters).
302 template <typename T>
USE(T)303 inline void USE(T) { }
304
305
306 // FUNCTION_ADDR(f) gets the address of a C function f.
307 #define FUNCTION_ADDR(f) \
308 (reinterpret_cast<v8::internal::Address>(reinterpret_cast<intptr_t>(f)))
309
310
311 // FUNCTION_CAST<F>(addr) casts an address into a function
312 // of type F. Used to invoke generated code from within C.
313 template <typename F>
FUNCTION_CAST(Address addr)314 F FUNCTION_CAST(Address addr) {
315 return reinterpret_cast<F>(reinterpret_cast<intptr_t>(addr));
316 }
317
318
319 // A macro to disallow the evil copy constructor and operator= functions
320 // This should be used in the private: declarations for a class
321 #define DISALLOW_COPY_AND_ASSIGN(TypeName) \
322 TypeName(const TypeName&); \
323 void operator=(const TypeName&)
324
325
326 // A macro to disallow all the implicit constructors, namely the
327 // default constructor, copy constructor and operator= functions.
328 //
329 // This should be used in the private: declarations for a class
330 // that wants to prevent anyone from instantiating it. This is
331 // especially useful for classes containing only static methods.
332 #define DISALLOW_IMPLICIT_CONSTRUCTORS(TypeName) \
333 TypeName(); \
334 DISALLOW_COPY_AND_ASSIGN(TypeName)
335
336
337 // Define used for helping GCC to make better inlining. Don't bother for debug
338 // builds. On GCC 3.4.5 using __attribute__((always_inline)) causes compilation
339 // errors in debug build.
340 #if defined(__GNUC__) && !defined(DEBUG)
341 #if (__GNUC__ >= 4)
342 #define INLINE(header) inline header __attribute__((always_inline))
343 #define NO_INLINE(header) header __attribute__((noinline))
344 #else
345 #define INLINE(header) inline __attribute__((always_inline)) header
346 #define NO_INLINE(header) __attribute__((noinline)) header
347 #endif
348 #else
349 #define INLINE(header) inline header
350 #define NO_INLINE(header) header
351 #endif
352
353
354 #if defined(__GNUC__) && __GNUC__ >= 4
355 #define MUST_USE_RESULT __attribute__ ((warn_unused_result))
356 #else
357 #define MUST_USE_RESULT
358 #endif
359
360 // -----------------------------------------------------------------------------
361 // Forward declarations for frequently used classes
362 // (sorted alphabetically)
363
364 class FreeStoreAllocationPolicy;
365 template <typename T, class P = FreeStoreAllocationPolicy> class List;
366
367 // -----------------------------------------------------------------------------
368 // Declarations for use in both the preparser and the rest of V8.
369
370 // The different language modes that V8 implements. ES5 defines two language
371 // modes: an unrestricted mode respectively a strict mode which are indicated by
372 // CLASSIC_MODE respectively STRICT_MODE in the enum. The harmony spec drafts
373 // for the next ES standard specify a new third mode which is called 'extended
374 // mode'. The extended mode is only available if the harmony flag is set. It is
375 // based on the 'strict mode' and adds new functionality to it. This means that
376 // most of the semantics of these two modes coincide.
377 //
378 // In the current draft the term 'base code' is used to refer to code that is
379 // neither in strict nor extended mode. However, the more distinguishing term
380 // 'classic mode' is used in V8 instead to avoid mix-ups.
381
382 enum LanguageMode {
383 CLASSIC_MODE,
384 STRICT_MODE,
385 EXTENDED_MODE
386 };
387
388
389 // The Strict Mode (ECMA-262 5th edition, 4.2.2).
390 //
391 // This flag is used in the backend to represent the language mode. So far
392 // there is no semantic difference between the strict and the extended mode in
393 // the backend, so both modes are represented by the kStrictMode value.
394 enum StrictModeFlag {
395 kNonStrictMode,
396 kStrictMode
397 };
398
399
400 } } // namespace v8::internal
401
402 #endif // V8_GLOBALS_H_
403