DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Implementation

Untracked file

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167
/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * The contents of this file are subject to the Netscape Public License
 * Version 1.0 (the "NPL"); you may not use this file except in
 * compliance with the NPL.  You may obtain a copy of the NPL at
 * http://www.mozilla.org/NPL/
 *
 * Software distributed under the NPL is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
 * for the specific language governing rights and limitations under the
 * NPL.
 *
 * The Initial Developer of this code under the NPL is Netscape
 * Communications Corporation.  Portions created by Netscape are
 * Copyright (C) 1998 Netscape Communications Corporation.  All Rights
 * Reserved.
 */

#ifndef jsnum_h___
#define jsnum_h___
/*
 * JS number (IEEE double) interface.
 *
 * JS numbers are optimistically stored in the top 31 bits of 32-bit integers,
 * but floating point literals, results that overflow 31 bits, and division and
 * modulus operands and results require a 64-bit IEEE double.  These are GC'ed
 * and pointed to by 32-bit jsvals on the stack and in object properties.
 *
 * When a JS number is treated as an object (followed by . or []), the runtime
 * wraps it with a JSObject whose valueOf method returns the unwrapped number.
 */

JS_BEGIN_EXTERN_C

#ifdef IS_LITTLE_ENDIAN
#define JSDOUBLE_HI32(x)        (((uint32 *)&(x))[1])
#define JSDOUBLE_LO32(x)        (((uint32 *)&(x))[0])
#else
#define JSDOUBLE_HI32(x)        (((uint32 *)&(x))[0])
#define JSDOUBLE_LO32(x)        (((uint32 *)&(x))[1])
#endif
#define JSDOUBLE_HI32_SIGNBIT   0x80000000
#define JSDOUBLE_HI32_EXPMASK   0x7ff00000
#define JSDOUBLE_HI32_MANTMASK  0x000fffff

#define JSDOUBLE_IS_NaN(x)                                                    \
    ((JSDOUBLE_HI32(x) & JSDOUBLE_HI32_EXPMASK) == JSDOUBLE_HI32_EXPMASK &&   \
     (JSDOUBLE_LO32(x) || (JSDOUBLE_HI32(x) & JSDOUBLE_HI32_MANTMASK)))

#define JSDOUBLE_IS_INFINITE(x)                                               \
    ((JSDOUBLE_HI32(x) & ~JSDOUBLE_HI32_SIGNBIT) == JSDOUBLE_HI32_EXPMASK &&   \
     !JSDOUBLE_LO32(x))

#define JSDOUBLE_IS_FINITE(x)                                                 \
    ((JSDOUBLE_HI32(x) & JSDOUBLE_HI32_EXPMASK) != JSDOUBLE_HI32_EXPMASK)

#define JSDOUBLE_IS_NEGZERO(d)  (JSDOUBLE_HI32(d) == JSDOUBLE_HI32_SIGNBIT && \
				 JSDOUBLE_LO32(d) == 0)

/*
 * JSDOUBLE_IS_INT first checks that d is neither NaN nor infinite, to avoid
 * raising SIGFPE on platforms such as Alpha Linux, then (only if the cast is
 * safe) leaves i as (jsint)d.  This also avoid anomalous NaN floating point
 * comparisons under MSVC.
 */
#define JSDOUBLE_IS_INT(d, i) (JSDOUBLE_IS_FINITE(d) && !JSDOUBLE_IS_NEGZERO(d) \
			       && ((d) == (i = (jsint)(d))))

/* Initialize the Number class, returning its prototype object. */
extern JSObject *
js_InitNumberClass(JSContext *cx, JSObject *obj);

/* GC-allocate a new JS number. */
extern jsdouble *
js_NewDouble(JSContext *cx, jsdouble d);

extern void
js_FinalizeDouble(JSContext *cx, jsdouble *dp);

extern JSBool
js_NewDoubleValue(JSContext *cx, jsdouble d, jsval *rval);

extern JSBool
js_NewNumberValue(JSContext *cx, jsdouble d, jsval *rval);

/* Construct a Number instance that wraps around d. */
extern JSObject *
js_NumberToObject(JSContext *cx, jsdouble d);

/* Convert a number to a GC'ed string. */
extern JSString *
js_NumberToString(JSContext *cx, jsdouble d);

/*
 * Convert a value to a number, returning false after reporting any error,
 * otherwise returning true with *dp set.
 */
extern JSBool
js_ValueToNumber(JSContext *cx, jsval v, jsdouble *dp);

/*
 * Convert a value or a double to an int32, according to the ECMA rules
 * for ToInt32.
 */
extern JSBool
js_ValueToECMAInt32(JSContext *cx, jsval v, int32 *ip);

extern JSBool
js_DoubleToECMAInt32(JSContext *cx, jsdouble d, int32 *ip);

/*
 * Convert a value or a double to a uint32, according to the ECMA rules
 * for ToUint32.
 */
extern JSBool
js_ValueToECMAUint32(JSContext *cx, jsval v, uint32 *ip);

extern JSBool
js_DoubleToECMAUint32(JSContext *cx, jsdouble d, uint32 *ip);

/*
 * Convert a value to a number, then to an int32 if it fits by rounding to
 * nearest; but failing with an error report if the double is out of range
 * or unordered.
 */
extern JSBool
js_ValueToInt32(JSContext *cx, jsval v, int32 *ip);

/*
 * Convert a value to a number, then to a uint16 according to the ECMA rules
 * for ToUint16.
 */
extern JSBool
js_ValueToUint16(JSContext *cx, jsval v, uint16 *ip);

/*
 * Convert a jsdouble to an integral number, stored in a jsdouble.
 * If d is NaN, return 0.  If d is an infinity, return it without conversion.
 */
extern jsdouble
js_DoubleToInteger(jsdouble d);

/*
 * Similar to strtod except that replaces overflows with infinities of the correct
 * sign and underflows with zeros of the correct sign.  Guaranteed to return the
 * closest double number to the given input in dp.
 * Also allows inputs of the form [+|-]Infinity, which produce an infinity of the
 * appropriate sign.  The case of the "Infinity" string must match.
 * If the string does not have a number in it, set *ep to s and return 0.0 in dp.
 * Return false if out of memory.
 */
extern JSBool
js_strtod(JSContext *cx, const jschar *s, const jschar **ep, jsdouble *dp);

/*
 * Similar to strtol except that handles integers of arbitrary size.  Guaranteed to
 * return the closest double number to the given input when radix is 10 or a power of 2.
 * May experience roundoff errors for very large numbers of a different radix.
 * If the string does not have a number in it, set *ep to s and return 0.0 in dp.
 * Return false if out of memory.
 */
extern JSBool
js_strtointeger(JSContext *cx, const jschar *s, const jschar **ep, jsint radix, jsdouble *dp);

JS_END_EXTERN_C

#endif /* jsnum_h___ */