llimits.h (8062B)
1 /* 2 ** $Id: llimits.h $ 3 ** Limits, basic types, and some other 'installation-dependent' definitions 4 ** See Copyright Notice in lua.h 5 */ 6 7 #ifndef llimits_h 8 #define llimits_h 9 10 11 #include <limits.h> 12 #include <stddef.h> 13 14 15 #include "lua.h" 16 17 18 /* 19 ** 'l_mem' is a signed integer big enough to count the total memory 20 ** used by Lua. (It is signed due to the use of debt in several 21 ** computations.) Usually, 'ptrdiff_t' should work, but we use 'long' 22 ** for 16-bit machines. 23 */ 24 #if defined(LUAI_MEM) /* { external definitions? */ 25 typedef LUAI_MEM l_mem; 26 typedef LUAI_UMEM lu_mem; 27 #elif LUAI_IS32INT /* }{ */ 28 typedef ptrdiff_t l_mem; 29 typedef size_t lu_mem; 30 #else /* 16-bit ints */ /* }{ */ 31 typedef long l_mem; 32 typedef unsigned long lu_mem; 33 #endif /* } */ 34 35 #define MAX_LMEM \ 36 cast(l_mem, (cast(lu_mem, 1) << (sizeof(l_mem) * 8 - 1)) - 1) 37 38 39 /* chars used as small naturals (so that 'char' is reserved for characters) */ 40 typedef unsigned char lu_byte; 41 typedef signed char ls_byte; 42 43 44 /* Type for thread status/error codes */ 45 typedef lu_byte TStatus; 46 47 /* The C API still uses 'int' for status/error codes */ 48 #define APIstatus(st) cast_int(st) 49 50 /* maximum value for size_t */ 51 #define MAX_SIZET ((size_t)(~(size_t)0)) 52 53 /* 54 ** Maximum size for strings and userdata visible for Lua; should be 55 ** representable as a lua_Integer and as a size_t. 56 */ 57 #define MAX_SIZE (sizeof(size_t) < sizeof(lua_Integer) ? MAX_SIZET \ 58 : cast_sizet(LUA_MAXINTEGER)) 59 60 /* 61 ** floor of the log2 of the maximum signed value for integral type 't'. 62 ** (That is, maximum 'n' such that '2^n' fits in the given signed type.) 63 */ 64 #define log2maxs(t) cast_int(sizeof(t) * 8 - 2) 65 66 67 /* 68 ** test whether an unsigned value is a power of 2 (or zero) 69 */ 70 #define ispow2(x) (((x) & ((x) - 1)) == 0) 71 72 73 /* number of chars of a literal string without the ending \0 */ 74 #define LL(x) (sizeof(x)/sizeof(char) - 1) 75 76 77 /* 78 ** conversion of pointer to unsigned integer: this is for hashing only; 79 ** there is no problem if the integer cannot hold the whole pointer 80 ** value. (In strict ISO C this may cause undefined behavior, but no 81 ** actual machine seems to bother.) 82 */ 83 #if !defined(LUA_USE_C89) && defined(__STDC_VERSION__) && \ 84 __STDC_VERSION__ >= 199901L 85 #include <stdint.h> 86 #if defined(UINTPTR_MAX) /* even in C99 this type is optional */ 87 #define L_P2I uintptr_t 88 #else /* no 'intptr'? */ 89 #define L_P2I uintmax_t /* use the largest available integer */ 90 #endif 91 #else /* C89 option */ 92 #define L_P2I size_t 93 #endif 94 95 #define point2uint(p) cast_uint((L_P2I)(p) & UINT_MAX) 96 97 98 99 /* types of 'usual argument conversions' for lua_Number and lua_Integer */ 100 typedef LUAI_UACNUMBER l_uacNumber; 101 typedef LUAI_UACINT l_uacInt; 102 103 104 /* 105 ** Internal assertions for in-house debugging 106 */ 107 #if defined LUAI_ASSERT 108 #undef NDEBUG 109 #include <assert.h> 110 #define lua_assert(c) assert(c) 111 #define assert_code(c) c 112 #endif 113 114 #if defined(lua_assert) 115 #else 116 #define lua_assert(c) ((void)0) 117 #define assert_code(c) ((void)0) 118 #endif 119 120 #define check_exp(c,e) (lua_assert(c), (e)) 121 /* to avoid problems with conditions too long */ 122 #define lua_longassert(c) assert_code((c) ? (void)0 : lua_assert(0)) 123 124 125 /* macro to avoid warnings about unused variables */ 126 #if !defined(UNUSED) 127 #define UNUSED(x) ((void)(x)) 128 #endif 129 130 131 /* type casts (a macro highlights casts in the code) */ 132 #define cast(t, exp) ((t)(exp)) 133 134 #define cast_void(i) cast(void, (i)) 135 #define cast_voidp(i) cast(void *, (i)) 136 #define cast_num(i) cast(lua_Number, (i)) 137 #define cast_int(i) cast(int, (i)) 138 #define cast_uint(i) cast(unsigned int, (i)) 139 #define cast_ulong(i) cast(unsigned long, (i)) 140 #define cast_byte(i) cast(lu_byte, (i)) 141 #define cast_uchar(i) cast(unsigned char, (i)) 142 #define cast_char(i) cast(char, (i)) 143 #define cast_charp(i) cast(char *, (i)) 144 #define cast_sizet(i) cast(size_t, (i)) 145 146 147 /* cast a signed lua_Integer to lua_Unsigned */ 148 #if !defined(l_castS2U) 149 #define l_castS2U(i) ((lua_Unsigned)(i)) 150 #endif 151 152 /* 153 ** cast a lua_Unsigned to a signed lua_Integer; this cast is 154 ** not strict ISO C, but two-complement architectures should 155 ** work fine. 156 */ 157 #if !defined(l_castU2S) 158 #define l_castU2S(i) ((lua_Integer)(i)) 159 #endif 160 161 /* 162 ** cast a size_t to lua_Integer: These casts are always valid for 163 ** sizes of Lua objects (see MAX_SIZE) 164 */ 165 #define cast_st2S(sz) ((lua_Integer)(sz)) 166 167 /* Cast a ptrdiff_t to size_t, when it is known that the minuend 168 ** comes from the subtrahend (the base) 169 */ 170 #define ct_diff2sz(df) ((size_t)(df)) 171 172 /* ptrdiff_t to lua_Integer */ 173 #define ct_diff2S(df) cast_st2S(ct_diff2sz(df)) 174 175 /* 176 ** Special type equivalent to '(void*)' for functions (to suppress some 177 ** warnings when converting function pointers) 178 */ 179 typedef void (*voidf)(void); 180 181 /* 182 ** Macro to convert pointer-to-void* to pointer-to-function. This cast 183 ** is undefined according to ISO C, but POSIX assumes that it works. 184 ** (The '__extension__' in gnu compilers is only to avoid warnings.) 185 */ 186 #if defined(__GNUC__) 187 #define cast_func(p) (__extension__ (voidf)(p)) 188 #else 189 #define cast_func(p) ((voidf)(p)) 190 #endif 191 192 193 194 /* 195 ** non-return type 196 */ 197 #if !defined(l_noret) 198 199 #if defined(__GNUC__) 200 #define l_noret void __attribute__((noreturn)) 201 #elif defined(_MSC_VER) && _MSC_VER >= 1200 202 #define l_noret void __declspec(noreturn) 203 #else 204 #define l_noret void 205 #endif 206 207 #endif 208 209 210 /* 211 ** Inline functions 212 */ 213 #if !defined(LUA_USE_C89) 214 #define l_inline inline 215 #elif defined(__GNUC__) 216 #define l_inline __inline__ 217 #else 218 #define l_inline /* empty */ 219 #endif 220 221 #define l_sinline static l_inline 222 223 224 /* 225 ** An unsigned with (at least) 4 bytes 226 */ 227 #if LUAI_IS32INT 228 typedef unsigned int l_uint32; 229 #else 230 typedef unsigned long l_uint32; 231 #endif 232 233 234 /* 235 ** The luai_num* macros define the primitive operations over numbers. 236 */ 237 238 /* floor division (defined as 'floor(a/b)') */ 239 #if !defined(luai_numidiv) 240 #define luai_numidiv(L,a,b) ((void)L, l_floor(luai_numdiv(L,a,b))) 241 #endif 242 243 /* float division */ 244 #if !defined(luai_numdiv) 245 #define luai_numdiv(L,a,b) ((a)/(b)) 246 #endif 247 248 /* 249 ** modulo: defined as 'a - floor(a/b)*b'; the direct computation 250 ** using this definition has several problems with rounding errors, 251 ** so it is better to use 'fmod'. 'fmod' gives the result of 252 ** 'a - trunc(a/b)*b', and therefore must be corrected when 253 ** 'trunc(a/b) ~= floor(a/b)'. That happens when the division has a 254 ** non-integer negative result: non-integer result is equivalent to 255 ** a non-zero remainder 'm'; negative result is equivalent to 'a' and 256 ** 'b' with different signs, or 'm' and 'b' with different signs 257 ** (as the result 'm' of 'fmod' has the same sign of 'a'). 258 */ 259 #if !defined(luai_nummod) 260 #define luai_nummod(L,a,b,m) \ 261 { (void)L; (m) = l_mathop(fmod)(a,b); \ 262 if (((m) > 0) ? (b) < 0 : ((m) < 0 && (b) > 0)) (m) += (b); } 263 #endif 264 265 /* exponentiation */ 266 #if !defined(luai_numpow) 267 #define luai_numpow(L,a,b) \ 268 ((void)L, (b == 2) ? (a)*(a) : l_mathop(pow)(a,b)) 269 #endif 270 271 /* the others are quite standard operations */ 272 #if !defined(luai_numadd) 273 #define luai_numadd(L,a,b) ((a)+(b)) 274 #define luai_numsub(L,a,b) ((a)-(b)) 275 #define luai_nummul(L,a,b) ((a)*(b)) 276 #define luai_numunm(L,a) (-(a)) 277 #define luai_numeq(a,b) ((a)==(b)) 278 #define luai_numlt(a,b) ((a)<(b)) 279 #define luai_numle(a,b) ((a)<=(b)) 280 #define luai_numgt(a,b) ((a)>(b)) 281 #define luai_numge(a,b) ((a)>=(b)) 282 #define luai_numisnan(a) (!luai_numeq((a), (a))) 283 #endif 284 285 286 /* 287 ** {================================================================== 288 ** "Abstraction Layer" for basic report of messages and errors 289 ** =================================================================== 290 */ 291 292 /* print a string */ 293 #if !defined(lua_writestring) 294 #define lua_writestring(s,l) fwrite((s), sizeof(char), (l), stdout) 295 #endif 296 297 /* print a newline and flush the output */ 298 #if !defined(lua_writeline) 299 #define lua_writeline() (lua_writestring("\n", 1), fflush(stdout)) 300 #endif 301 302 /* print an error message */ 303 #if !defined(lua_writestringerror) 304 #define lua_writestringerror(s,p) \ 305 (fprintf(stderr, (s), (p)), fflush(stderr)) 306 #endif 307 308 /* }================================================================== */ 309 310 #endif 311