blob: a871e7ce2bf9c1250d27afef0f4d638576dc606b [file] [log] [blame]
// Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
// part of "core_patch.dart";
/// VM implementation of int.
@patch
class int {
@patch
const factory int.fromEnvironment(String name, {int defaultValue})
native "Integer_fromEnvironment";
int _bitAndFromSmi(_Smi other);
int _bitAndFromInteger(int other);
int _bitOrFromInteger(int other);
int _bitXorFromInteger(int other);
int _shrFromInteger(int other);
int _shlFromInteger(int other);
static int _tryParseSmi(String str, int first, int last) {
assert(first <= last);
var ix = first;
var sign = 1;
var c = str.codeUnitAt(ix);
// Check for leading '+' or '-'.
if ((c == 0x2b) || (c == 0x2d)) {
ix++;
sign = 0x2c - c; // -1 for '-', +1 for '+'.
if (ix > last) {
return null; // Empty.
}
}
var smiLimit = is64Bit ? 18 : 9;
if ((last - ix) >= smiLimit) {
return null; // May not fit into a Smi.
}
var result = 0;
for (int i = ix; i <= last; i++) {
var c = 0x30 ^ str.codeUnitAt(i);
if (9 < c) {
return null;
}
result = 10 * result + c;
}
return sign * result;
}
@patch
static int parse(String source, {int radix, int onError(String source)}) {
if (source == null) throw new ArgumentError("The source must not be null");
if (source.isEmpty) return _throwFormatException(onError, source, 0, radix);
if (radix == null || radix == 10) {
// Try parsing immediately, without trimming whitespace.
int result = _tryParseSmi(source, 0, source.length - 1);
if (result != null) return result;
} else if (radix < 2 || radix > 36) {
throw new RangeError("Radix $radix not in range 2..36");
}
// Split here so improve odds of parse being inlined and the checks omitted.
return _parse(source, radix, onError);
}
static int _parse(_StringBase source, int radix, onError) {
int end = source._lastNonWhitespace() + 1;
if (end == 0) {
return _throwFormatException(onError, source, source.length, radix);
}
int start = source._firstNonWhitespace();
int first = source.codeUnitAt(start);
int sign = 1;
if (first == 0x2b /* + */ || first == 0x2d /* - */) {
sign = 0x2c - first; // -1 if '-', +1 if '+'.
start++;
if (start == end) {
return _throwFormatException(onError, source, end, radix);
}
first = source.codeUnitAt(start);
}
if (radix == null) {
// check for 0x prefix.
int index = start;
if (first == 0x30 /* 0 */) {
index++;
if (index == end) return 0;
first = source.codeUnitAt(index);
if ((first | 0x20) == 0x78 /* x */) {
index++;
if (index == end) {
return _throwFormatException(onError, source, index, null);
}
int result = _parseRadix(source, 16, index, end, sign, sign > 0);
if (result == null) {
return _throwFormatException(onError, source, null, null);
}
return result;
}
}
radix = 10;
}
int result = _parseRadix(source, radix, start, end, sign, false);
if (result == null) {
return _throwFormatException(onError, source, null, radix);
}
return result;
}
@patch
static int tryParse(String source, {int radix}) {
if (source == null) throw new ArgumentError("The source must not be null");
if (source.isEmpty) return null;
if (radix == null || radix == 10) {
// Try parsing immediately, without trimming whitespace.
int result = _tryParseSmi(source, 0, source.length - 1);
if (result != null) return result;
} else if (radix < 2 || radix > 36) {
throw new RangeError("Radix $radix not in range 2..36");
}
return _parse(source, radix, _kNull);
}
static Null _kNull(_) => null;
static int _throwFormatException(onError, source, index, radix) {
if (onError != null) return onError(source);
if (radix == null) {
throw new FormatException("Invalid number", source, index);
}
throw new FormatException("Invalid radix-$radix number", source, index);
}
static int _parseRadix(
String source, int radix, int start, int end, int sign, bool allowU64) {
int tableIndex = (radix - 2) * 4 + (is64Bit ? 2 : 0);
int blockSize = _PARSE_LIMITS[tableIndex];
int length = end - start;
if (length <= blockSize) {
_Smi smi = _parseBlock(source, radix, start, end);
if (smi != null) return sign * smi;
return null;
}
// Often cheaper than: int smallBlockSize = length % blockSize;
// because digit count generally tends towards smaller. rather
// than larger.
int smallBlockSize = length;
while (smallBlockSize >= blockSize) smallBlockSize -= blockSize;
int result = 0;
if (smallBlockSize > 0) {
int blockEnd = start + smallBlockSize;
_Smi smi = _parseBlock(source, radix, start, blockEnd);
if (smi == null) return null;
result = sign * smi;
start = blockEnd;
}
int multiplier = _PARSE_LIMITS[tableIndex + 1];
int positiveOverflowLimit = 0;
int negativeOverflowLimit = 0;
tableIndex = tableIndex << 1; // pre-multiply by 2 for simpler indexing
positiveOverflowLimit = _int64OverflowLimits[tableIndex];
if (positiveOverflowLimit == 0) {
positiveOverflowLimit = _initInt64OverflowLimits(tableIndex, multiplier);
}
negativeOverflowLimit = _int64OverflowLimits[tableIndex + 1];
int blockEnd = start + blockSize;
do {
_Smi smi = _parseBlock(source, radix, start, blockEnd);
if (smi == null) return null;
if (result >= positiveOverflowLimit) {
if ((result > positiveOverflowLimit) ||
(smi > _int64OverflowLimits[tableIndex + 2])) {
// Although the unsigned overflow limits do not depend on the
// platform, the multiplier and block size, which are used to
// compute it, do.
int X = is64Bit ? 1 : 0;
if (allowU64 &&
!(result >= _int64UnsignedOverflowLimits[X] &&
(result > _int64UnsignedOverflowLimits[X] ||
smi > _int64UnsignedSmiOverflowLimits[X])) &&
blockEnd + blockSize > end) {
return (result * multiplier) + smi;
}
return null;
}
} else if (result <= negativeOverflowLimit) {
if ((result < negativeOverflowLimit) ||
(smi > _int64OverflowLimits[tableIndex + 3])) {
return null;
}
}
result = (result * multiplier) + (sign * smi);
start = blockEnd;
blockEnd = start + blockSize;
} while (blockEnd <= end);
return result;
}
// Parse block of digits into a Smi.
static _Smi _parseBlock(String source, int radix, int start, int end) {
_Smi result = 0;
if (radix <= 10) {
for (int i = start; i < end; i++) {
int digit = source.codeUnitAt(i) ^ 0x30;
if (digit >= radix) return null;
result = radix * result + digit;
}
} else {
for (int i = start; i < end; i++) {
int char = source.codeUnitAt(i);
int digit = char ^ 0x30;
if (digit > 9) {
digit = (char | 0x20) - (0x61 - 10);
if (digit < 10 || digit >= radix) return null;
}
result = radix * result + digit;
}
}
return result;
}
// For each radix, 2-36, how many digits are guaranteed to fit in a smi,
// and magnitude of such a block (radix ** digit-count).
// 32-bit limit/multiplier at (radix - 2)*4, 64-bit limit at (radix-2)*4+2
static const _PARSE_LIMITS = const [
30, 1073741824, 62, 4611686018427387904, // radix: 2
18, 387420489, 39, 4052555153018976267,
15, 1073741824, 30, 1152921504606846976,
12, 244140625, 26, 1490116119384765625, // radix: 5
11, 362797056, 23, 789730223053602816,
10, 282475249, 22, 3909821048582988049,
10, 1073741824, 20, 1152921504606846976,
9, 387420489, 19, 1350851717672992089,
9, 1000000000, 18, 1000000000000000000, // radix: 10
8, 214358881, 17, 505447028499293771,
8, 429981696, 17, 2218611106740436992,
8, 815730721, 16, 665416609183179841,
7, 105413504, 16, 2177953337809371136,
7, 170859375, 15, 437893890380859375, // radix: 15
7, 268435456, 15, 1152921504606846976,
7, 410338673, 15, 2862423051509815793,
7, 612220032, 14, 374813367582081024,
7, 893871739, 14, 799006685782884121,
6, 64000000, 14, 1638400000000000000, // radix: 20
6, 85766121, 14, 3243919932521508681,
6, 113379904, 13, 282810057883082752,
6, 148035889, 13, 504036361936467383,
6, 191102976, 13, 876488338465357824,
6, 244140625, 13, 1490116119384765625, // radix: 25
6, 308915776, 13, 2481152873203736576,
6, 387420489, 13, 4052555153018976267,
6, 481890304, 12, 232218265089212416,
6, 594823321, 12, 353814783205469041,
6, 729000000, 12, 531441000000000000, // radix: 30
6, 887503681, 12, 787662783788549761,
6, 1073741824, 12, 1152921504606846976,
5, 39135393, 12, 1667889514952984961,
5, 45435424, 12, 2386420683693101056,
5, 52521875, 12, 3379220508056640625, // radix: 35
5, 60466176, 11, 131621703842267136,
];
static const _maxInt64 = 0x7fffffffffffffff;
static const _minInt64 = -0x8000000000000000;
static const _int64UnsignedOverflowLimits = const [0xfffffffff, 0xf];
static const _int64UnsignedSmiOverflowLimits = const [
0xfffffff,
0xfffffffffffffff
];
/// Calculation of the expression
///
/// result = (result * multiplier) + (sign * smi)
///
/// in `_parseRadix()` may overflow 64-bit integers. In such case,
/// `int.parse()` should stop with an error.
///
/// This table is lazily filled with int64 overflow limits for result and smi.
/// For each multiplier from `_PARSE_LIMITS[tableIndex + 1]` this table
/// contains
///
/// * `[tableIndex*2]` = positive limit for result
/// * `[tableIndex*2 + 1]` = negative limit for result
/// * `[tableIndex*2 + 2]` = limit for smi if result is exactly at positive limit
/// * `[tableIndex*2 + 3]` = limit for smi if result is exactly at negative limit
static final Int64List _int64OverflowLimits =
new Int64List(_PARSE_LIMITS.length * 2);
static int _initInt64OverflowLimits(int tableIndex, int multiplier) {
_int64OverflowLimits[tableIndex] = _maxInt64 ~/ multiplier;
_int64OverflowLimits[tableIndex + 1] = _minInt64 ~/ multiplier;
_int64OverflowLimits[tableIndex + 2] = _maxInt64.remainder(multiplier);
_int64OverflowLimits[tableIndex + 3] = -(_minInt64.remainder(multiplier));
return _int64OverflowLimits[tableIndex];
}
}