mirror of https://github.com/lukechilds/node.git
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
1083 lines
34 KiB
1083 lines
34 KiB
// Copyright 2006-2008 the V8 project authors. All rights reserved.
|
|
// Redistribution and use in source and binary forms, with or without
|
|
// modification, are permitted provided that the following conditions are
|
|
// met:
|
|
//
|
|
// * Redistributions of source code must retain the above copyright
|
|
// notice, this list of conditions and the following disclaimer.
|
|
// * Redistributions in binary form must reproduce the above
|
|
// copyright notice, this list of conditions and the following
|
|
// disclaimer in the documentation and/or other materials provided
|
|
// with the distribution.
|
|
// * Neither the name of Google Inc. nor the names of its
|
|
// contributors may be used to endorse or promote products derived
|
|
// from this software without specific prior written permission.
|
|
//
|
|
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
|
|
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
|
|
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
|
|
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
|
|
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
|
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
|
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
|
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
|
|
#include <stdarg.h>
|
|
#include <limits.h>
|
|
|
|
#include "v8.h"
|
|
|
|
#include "conversions-inl.h"
|
|
#include "dtoa.h"
|
|
#include "factory.h"
|
|
#include "scanner-base.h"
|
|
#include "strtod.h"
|
|
|
|
namespace v8 {
|
|
namespace internal {
|
|
|
|
namespace {
|
|
|
|
// C++-style iterator adaptor for StringInputBuffer
|
|
// (unlike C++ iterators the end-marker has different type).
|
|
class StringInputBufferIterator {
|
|
public:
|
|
class EndMarker {};
|
|
|
|
explicit StringInputBufferIterator(StringInputBuffer* buffer);
|
|
|
|
int operator*() const;
|
|
void operator++();
|
|
bool operator==(EndMarker const&) const { return end_; }
|
|
bool operator!=(EndMarker const& m) const { return !end_; }
|
|
|
|
private:
|
|
StringInputBuffer* const buffer_;
|
|
int current_;
|
|
bool end_;
|
|
};
|
|
|
|
|
|
StringInputBufferIterator::StringInputBufferIterator(
|
|
StringInputBuffer* buffer) : buffer_(buffer) {
|
|
++(*this);
|
|
}
|
|
|
|
int StringInputBufferIterator::operator*() const {
|
|
return current_;
|
|
}
|
|
|
|
|
|
void StringInputBufferIterator::operator++() {
|
|
end_ = !buffer_->has_more();
|
|
if (!end_) {
|
|
current_ = buffer_->GetNext();
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
template <class Iterator, class EndMark>
|
|
static bool SubStringEquals(Iterator* current,
|
|
EndMark end,
|
|
const char* substring) {
|
|
ASSERT(**current == *substring);
|
|
for (substring++; *substring != '\0'; substring++) {
|
|
++*current;
|
|
if (*current == end || **current != *substring) return false;
|
|
}
|
|
++*current;
|
|
return true;
|
|
}
|
|
|
|
|
|
// Maximum number of significant digits in decimal representation.
|
|
// The longest possible double in decimal representation is
|
|
// (2^53 - 1) * 2 ^ -1074 that is (2 ^ 53 - 1) * 5 ^ 1074 / 10 ^ 1074
|
|
// (768 digits). If we parse a number whose first digits are equal to a
|
|
// mean of 2 adjacent doubles (that could have up to 769 digits) the result
|
|
// must be rounded to the bigger one unless the tail consists of zeros, so
|
|
// we don't need to preserve all the digits.
|
|
const int kMaxSignificantDigits = 772;
|
|
|
|
|
|
static const double JUNK_STRING_VALUE = OS::nan_value();
|
|
|
|
|
|
// Returns true if a nonspace found and false if the end has reached.
|
|
template <class Iterator, class EndMark>
|
|
static inline bool AdvanceToNonspace(Iterator* current, EndMark end) {
|
|
while (*current != end) {
|
|
if (!ScannerConstants::kIsWhiteSpace.get(**current)) return true;
|
|
++*current;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
|
|
static bool isDigit(int x, int radix) {
|
|
return (x >= '0' && x <= '9' && x < '0' + radix)
|
|
|| (radix > 10 && x >= 'a' && x < 'a' + radix - 10)
|
|
|| (radix > 10 && x >= 'A' && x < 'A' + radix - 10);
|
|
}
|
|
|
|
|
|
static double SignedZero(bool sign) {
|
|
return sign ? -0.0 : 0.0;
|
|
}
|
|
|
|
|
|
// Parsing integers with radix 2, 4, 8, 16, 32. Assumes current != end.
|
|
template <int radix_log_2, class Iterator, class EndMark>
|
|
static double InternalStringToIntDouble(Iterator current,
|
|
EndMark end,
|
|
bool sign,
|
|
bool allow_trailing_junk) {
|
|
ASSERT(current != end);
|
|
|
|
// Skip leading 0s.
|
|
while (*current == '0') {
|
|
++current;
|
|
if (current == end) return SignedZero(sign);
|
|
}
|
|
|
|
int64_t number = 0;
|
|
int exponent = 0;
|
|
const int radix = (1 << radix_log_2);
|
|
|
|
do {
|
|
int digit;
|
|
if (*current >= '0' && *current <= '9' && *current < '0' + radix) {
|
|
digit = static_cast<char>(*current) - '0';
|
|
} else if (radix > 10 && *current >= 'a' && *current < 'a' + radix - 10) {
|
|
digit = static_cast<char>(*current) - 'a' + 10;
|
|
} else if (radix > 10 && *current >= 'A' && *current < 'A' + radix - 10) {
|
|
digit = static_cast<char>(*current) - 'A' + 10;
|
|
} else {
|
|
if (allow_trailing_junk || !AdvanceToNonspace(¤t, end)) {
|
|
break;
|
|
} else {
|
|
return JUNK_STRING_VALUE;
|
|
}
|
|
}
|
|
|
|
number = number * radix + digit;
|
|
int overflow = static_cast<int>(number >> 53);
|
|
if (overflow != 0) {
|
|
// Overflow occurred. Need to determine which direction to round the
|
|
// result.
|
|
int overflow_bits_count = 1;
|
|
while (overflow > 1) {
|
|
overflow_bits_count++;
|
|
overflow >>= 1;
|
|
}
|
|
|
|
int dropped_bits_mask = ((1 << overflow_bits_count) - 1);
|
|
int dropped_bits = static_cast<int>(number) & dropped_bits_mask;
|
|
number >>= overflow_bits_count;
|
|
exponent = overflow_bits_count;
|
|
|
|
bool zero_tail = true;
|
|
while (true) {
|
|
++current;
|
|
if (current == end || !isDigit(*current, radix)) break;
|
|
zero_tail = zero_tail && *current == '0';
|
|
exponent += radix_log_2;
|
|
}
|
|
|
|
if (!allow_trailing_junk && AdvanceToNonspace(¤t, end)) {
|
|
return JUNK_STRING_VALUE;
|
|
}
|
|
|
|
int middle_value = (1 << (overflow_bits_count - 1));
|
|
if (dropped_bits > middle_value) {
|
|
number++; // Rounding up.
|
|
} else if (dropped_bits == middle_value) {
|
|
// Rounding to even to consistency with decimals: half-way case rounds
|
|
// up if significant part is odd and down otherwise.
|
|
if ((number & 1) != 0 || !zero_tail) {
|
|
number++; // Rounding up.
|
|
}
|
|
}
|
|
|
|
// Rounding up may cause overflow.
|
|
if ((number & ((int64_t)1 << 53)) != 0) {
|
|
exponent++;
|
|
number >>= 1;
|
|
}
|
|
break;
|
|
}
|
|
++current;
|
|
} while (current != end);
|
|
|
|
ASSERT(number < ((int64_t)1 << 53));
|
|
ASSERT(static_cast<int64_t>(static_cast<double>(number)) == number);
|
|
|
|
if (exponent == 0) {
|
|
if (sign) {
|
|
if (number == 0) return -0.0;
|
|
number = -number;
|
|
}
|
|
return static_cast<double>(number);
|
|
}
|
|
|
|
ASSERT(number != 0);
|
|
// The double could be constructed faster from number (mantissa), exponent
|
|
// and sign. Assuming it's a rare case more simple code is used.
|
|
return static_cast<double>(sign ? -number : number) * pow(2.0, exponent);
|
|
}
|
|
|
|
|
|
template <class Iterator, class EndMark>
|
|
static double InternalStringToInt(Iterator current, EndMark end, int radix) {
|
|
const bool allow_trailing_junk = true;
|
|
const double empty_string_val = JUNK_STRING_VALUE;
|
|
|
|
if (!AdvanceToNonspace(¤t, end)) return empty_string_val;
|
|
|
|
bool sign = false;
|
|
bool leading_zero = false;
|
|
|
|
if (*current == '+') {
|
|
// Ignore leading sign; skip following spaces.
|
|
++current;
|
|
if (!AdvanceToNonspace(¤t, end)) return JUNK_STRING_VALUE;
|
|
} else if (*current == '-') {
|
|
++current;
|
|
if (!AdvanceToNonspace(¤t, end)) return JUNK_STRING_VALUE;
|
|
sign = true;
|
|
}
|
|
|
|
if (radix == 0) {
|
|
// Radix detection.
|
|
if (*current == '0') {
|
|
++current;
|
|
if (current == end) return SignedZero(sign);
|
|
if (*current == 'x' || *current == 'X') {
|
|
radix = 16;
|
|
++current;
|
|
if (current == end) return JUNK_STRING_VALUE;
|
|
} else {
|
|
radix = 8;
|
|
leading_zero = true;
|
|
}
|
|
} else {
|
|
radix = 10;
|
|
}
|
|
} else if (radix == 16) {
|
|
if (*current == '0') {
|
|
// Allow "0x" prefix.
|
|
++current;
|
|
if (current == end) return SignedZero(sign);
|
|
if (*current == 'x' || *current == 'X') {
|
|
++current;
|
|
if (current == end) return JUNK_STRING_VALUE;
|
|
} else {
|
|
leading_zero = true;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (radix < 2 || radix > 36) return JUNK_STRING_VALUE;
|
|
|
|
// Skip leading zeros.
|
|
while (*current == '0') {
|
|
leading_zero = true;
|
|
++current;
|
|
if (current == end) return SignedZero(sign);
|
|
}
|
|
|
|
if (!leading_zero && !isDigit(*current, radix)) {
|
|
return JUNK_STRING_VALUE;
|
|
}
|
|
|
|
if (IsPowerOf2(radix)) {
|
|
switch (radix) {
|
|
case 2:
|
|
return InternalStringToIntDouble<1>(
|
|
current, end, sign, allow_trailing_junk);
|
|
case 4:
|
|
return InternalStringToIntDouble<2>(
|
|
current, end, sign, allow_trailing_junk);
|
|
case 8:
|
|
return InternalStringToIntDouble<3>(
|
|
current, end, sign, allow_trailing_junk);
|
|
|
|
case 16:
|
|
return InternalStringToIntDouble<4>(
|
|
current, end, sign, allow_trailing_junk);
|
|
|
|
case 32:
|
|
return InternalStringToIntDouble<5>(
|
|
current, end, sign, allow_trailing_junk);
|
|
default:
|
|
UNREACHABLE();
|
|
}
|
|
}
|
|
|
|
if (radix == 10) {
|
|
// Parsing with strtod.
|
|
const int kMaxSignificantDigits = 309; // Doubles are less than 1.8e308.
|
|
// The buffer may contain up to kMaxSignificantDigits + 1 digits and a zero
|
|
// end.
|
|
const int kBufferSize = kMaxSignificantDigits + 2;
|
|
char buffer[kBufferSize];
|
|
int buffer_pos = 0;
|
|
while (*current >= '0' && *current <= '9') {
|
|
if (buffer_pos <= kMaxSignificantDigits) {
|
|
// If the number has more than kMaxSignificantDigits it will be parsed
|
|
// as infinity.
|
|
ASSERT(buffer_pos < kBufferSize);
|
|
buffer[buffer_pos++] = static_cast<char>(*current);
|
|
}
|
|
++current;
|
|
if (current == end) break;
|
|
}
|
|
|
|
if (!allow_trailing_junk && AdvanceToNonspace(¤t, end)) {
|
|
return JUNK_STRING_VALUE;
|
|
}
|
|
|
|
ASSERT(buffer_pos < kBufferSize);
|
|
buffer[buffer_pos] = '\0';
|
|
Vector<const char> buffer_vector(buffer, buffer_pos);
|
|
return sign ? -Strtod(buffer_vector, 0) : Strtod(buffer_vector, 0);
|
|
}
|
|
|
|
// The following code causes accumulating rounding error for numbers greater
|
|
// than ~2^56. It's explicitly allowed in the spec: "if R is not 2, 4, 8, 10,
|
|
// 16, or 32, then mathInt may be an implementation-dependent approximation to
|
|
// the mathematical integer value" (15.1.2.2).
|
|
|
|
int lim_0 = '0' + (radix < 10 ? radix : 10);
|
|
int lim_a = 'a' + (radix - 10);
|
|
int lim_A = 'A' + (radix - 10);
|
|
|
|
// NOTE: The code for computing the value may seem a bit complex at
|
|
// first glance. It is structured to use 32-bit multiply-and-add
|
|
// loops as long as possible to avoid loosing precision.
|
|
|
|
double v = 0.0;
|
|
bool done = false;
|
|
do {
|
|
// Parse the longest part of the string starting at index j
|
|
// possible while keeping the multiplier, and thus the part
|
|
// itself, within 32 bits.
|
|
unsigned int part = 0, multiplier = 1;
|
|
while (true) {
|
|
int d;
|
|
if (*current >= '0' && *current < lim_0) {
|
|
d = *current - '0';
|
|
} else if (*current >= 'a' && *current < lim_a) {
|
|
d = *current - 'a' + 10;
|
|
} else if (*current >= 'A' && *current < lim_A) {
|
|
d = *current - 'A' + 10;
|
|
} else {
|
|
done = true;
|
|
break;
|
|
}
|
|
|
|
// Update the value of the part as long as the multiplier fits
|
|
// in 32 bits. When we can't guarantee that the next iteration
|
|
// will not overflow the multiplier, we stop parsing the part
|
|
// by leaving the loop.
|
|
const unsigned int kMaximumMultiplier = 0xffffffffU / 36;
|
|
uint32_t m = multiplier * radix;
|
|
if (m > kMaximumMultiplier) break;
|
|
part = part * radix + d;
|
|
multiplier = m;
|
|
ASSERT(multiplier > part);
|
|
|
|
++current;
|
|
if (current == end) {
|
|
done = true;
|
|
break;
|
|
}
|
|
}
|
|
|
|
// Update the value and skip the part in the string.
|
|
v = v * multiplier + part;
|
|
} while (!done);
|
|
|
|
if (!allow_trailing_junk && AdvanceToNonspace(¤t, end)) {
|
|
return JUNK_STRING_VALUE;
|
|
}
|
|
|
|
return sign ? -v : v;
|
|
}
|
|
|
|
|
|
// Converts a string to a double value. Assumes the Iterator supports
|
|
// the following operations:
|
|
// 1. current == end (other ops are not allowed), current != end.
|
|
// 2. *current - gets the current character in the sequence.
|
|
// 3. ++current (advances the position).
|
|
template <class Iterator, class EndMark>
|
|
static double InternalStringToDouble(Iterator current,
|
|
EndMark end,
|
|
int flags,
|
|
double empty_string_val) {
|
|
// To make sure that iterator dereferencing is valid the following
|
|
// convention is used:
|
|
// 1. Each '++current' statement is followed by check for equality to 'end'.
|
|
// 2. If AdvanceToNonspace returned false then current == end.
|
|
// 3. If 'current' becomes be equal to 'end' the function returns or goes to
|
|
// 'parsing_done'.
|
|
// 4. 'current' is not dereferenced after the 'parsing_done' label.
|
|
// 5. Code before 'parsing_done' may rely on 'current != end'.
|
|
if (!AdvanceToNonspace(¤t, end)) return empty_string_val;
|
|
|
|
const bool allow_trailing_junk = (flags & ALLOW_TRAILING_JUNK) != 0;
|
|
|
|
// The longest form of simplified number is: "-<significant digits>'.1eXXX\0".
|
|
const int kBufferSize = kMaxSignificantDigits + 10;
|
|
char buffer[kBufferSize]; // NOLINT: size is known at compile time.
|
|
int buffer_pos = 0;
|
|
|
|
// Exponent will be adjusted if insignificant digits of the integer part
|
|
// or insignificant leading zeros of the fractional part are dropped.
|
|
int exponent = 0;
|
|
int significant_digits = 0;
|
|
int insignificant_digits = 0;
|
|
bool nonzero_digit_dropped = false;
|
|
bool fractional_part = false;
|
|
|
|
bool sign = false;
|
|
|
|
if (*current == '+') {
|
|
// Ignore leading sign.
|
|
++current;
|
|
if (current == end) return JUNK_STRING_VALUE;
|
|
} else if (*current == '-') {
|
|
++current;
|
|
if (current == end) return JUNK_STRING_VALUE;
|
|
sign = true;
|
|
}
|
|
|
|
static const char kInfinitySymbol[] = "Infinity";
|
|
if (*current == kInfinitySymbol[0]) {
|
|
if (!SubStringEquals(¤t, end, kInfinitySymbol)) {
|
|
return JUNK_STRING_VALUE;
|
|
}
|
|
|
|
if (!allow_trailing_junk && AdvanceToNonspace(¤t, end)) {
|
|
return JUNK_STRING_VALUE;
|
|
}
|
|
|
|
ASSERT(buffer_pos == 0);
|
|
return sign ? -V8_INFINITY : V8_INFINITY;
|
|
}
|
|
|
|
bool leading_zero = false;
|
|
if (*current == '0') {
|
|
++current;
|
|
if (current == end) return SignedZero(sign);
|
|
|
|
leading_zero = true;
|
|
|
|
// It could be hexadecimal value.
|
|
if ((flags & ALLOW_HEX) && (*current == 'x' || *current == 'X')) {
|
|
++current;
|
|
if (current == end || !isDigit(*current, 16)) {
|
|
return JUNK_STRING_VALUE; // "0x".
|
|
}
|
|
|
|
return InternalStringToIntDouble<4>(current,
|
|
end,
|
|
sign,
|
|
allow_trailing_junk);
|
|
}
|
|
|
|
// Ignore leading zeros in the integer part.
|
|
while (*current == '0') {
|
|
++current;
|
|
if (current == end) return SignedZero(sign);
|
|
}
|
|
}
|
|
|
|
bool octal = leading_zero && (flags & ALLOW_OCTALS) != 0;
|
|
|
|
// Copy significant digits of the integer part (if any) to the buffer.
|
|
while (*current >= '0' && *current <= '9') {
|
|
if (significant_digits < kMaxSignificantDigits) {
|
|
ASSERT(buffer_pos < kBufferSize);
|
|
buffer[buffer_pos++] = static_cast<char>(*current);
|
|
significant_digits++;
|
|
// Will later check if it's an octal in the buffer.
|
|
} else {
|
|
insignificant_digits++; // Move the digit into the exponential part.
|
|
nonzero_digit_dropped = nonzero_digit_dropped || *current != '0';
|
|
}
|
|
octal = octal && *current < '8';
|
|
++current;
|
|
if (current == end) goto parsing_done;
|
|
}
|
|
|
|
if (significant_digits == 0) {
|
|
octal = false;
|
|
}
|
|
|
|
if (*current == '.') {
|
|
if (octal && !allow_trailing_junk) return JUNK_STRING_VALUE;
|
|
if (octal) goto parsing_done;
|
|
|
|
++current;
|
|
if (current == end) {
|
|
if (significant_digits == 0 && !leading_zero) {
|
|
return JUNK_STRING_VALUE;
|
|
} else {
|
|
goto parsing_done;
|
|
}
|
|
}
|
|
|
|
if (significant_digits == 0) {
|
|
// octal = false;
|
|
// Integer part consists of 0 or is absent. Significant digits start after
|
|
// leading zeros (if any).
|
|
while (*current == '0') {
|
|
++current;
|
|
if (current == end) return SignedZero(sign);
|
|
exponent--; // Move this 0 into the exponent.
|
|
}
|
|
}
|
|
|
|
// We don't emit a '.', but adjust the exponent instead.
|
|
fractional_part = true;
|
|
|
|
// There is a fractional part.
|
|
while (*current >= '0' && *current <= '9') {
|
|
if (significant_digits < kMaxSignificantDigits) {
|
|
ASSERT(buffer_pos < kBufferSize);
|
|
buffer[buffer_pos++] = static_cast<char>(*current);
|
|
significant_digits++;
|
|
exponent--;
|
|
} else {
|
|
// Ignore insignificant digits in the fractional part.
|
|
nonzero_digit_dropped = nonzero_digit_dropped || *current != '0';
|
|
}
|
|
++current;
|
|
if (current == end) goto parsing_done;
|
|
}
|
|
}
|
|
|
|
if (!leading_zero && exponent == 0 && significant_digits == 0) {
|
|
// If leading_zeros is true then the string contains zeros.
|
|
// If exponent < 0 then string was [+-]\.0*...
|
|
// If significant_digits != 0 the string is not equal to 0.
|
|
// Otherwise there are no digits in the string.
|
|
return JUNK_STRING_VALUE;
|
|
}
|
|
|
|
// Parse exponential part.
|
|
if (*current == 'e' || *current == 'E') {
|
|
if (octal) return JUNK_STRING_VALUE;
|
|
++current;
|
|
if (current == end) {
|
|
if (allow_trailing_junk) {
|
|
goto parsing_done;
|
|
} else {
|
|
return JUNK_STRING_VALUE;
|
|
}
|
|
}
|
|
char sign = '+';
|
|
if (*current == '+' || *current == '-') {
|
|
sign = static_cast<char>(*current);
|
|
++current;
|
|
if (current == end) {
|
|
if (allow_trailing_junk) {
|
|
goto parsing_done;
|
|
} else {
|
|
return JUNK_STRING_VALUE;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (current == end || *current < '0' || *current > '9') {
|
|
if (allow_trailing_junk) {
|
|
goto parsing_done;
|
|
} else {
|
|
return JUNK_STRING_VALUE;
|
|
}
|
|
}
|
|
|
|
const int max_exponent = INT_MAX / 2;
|
|
ASSERT(-max_exponent / 2 <= exponent && exponent <= max_exponent / 2);
|
|
int num = 0;
|
|
do {
|
|
// Check overflow.
|
|
int digit = *current - '0';
|
|
if (num >= max_exponent / 10
|
|
&& !(num == max_exponent / 10 && digit <= max_exponent % 10)) {
|
|
num = max_exponent;
|
|
} else {
|
|
num = num * 10 + digit;
|
|
}
|
|
++current;
|
|
} while (current != end && *current >= '0' && *current <= '9');
|
|
|
|
exponent += (sign == '-' ? -num : num);
|
|
}
|
|
|
|
if (!allow_trailing_junk && AdvanceToNonspace(¤t, end)) {
|
|
return JUNK_STRING_VALUE;
|
|
}
|
|
|
|
parsing_done:
|
|
exponent += insignificant_digits;
|
|
|
|
if (octal) {
|
|
return InternalStringToIntDouble<3>(buffer,
|
|
buffer + buffer_pos,
|
|
sign,
|
|
allow_trailing_junk);
|
|
}
|
|
|
|
if (nonzero_digit_dropped) {
|
|
buffer[buffer_pos++] = '1';
|
|
exponent--;
|
|
}
|
|
|
|
ASSERT(buffer_pos < kBufferSize);
|
|
buffer[buffer_pos] = '\0';
|
|
|
|
double converted = Strtod(Vector<const char>(buffer, buffer_pos), exponent);
|
|
return sign ? -converted : converted;
|
|
}
|
|
|
|
|
|
double StringToDouble(String* str, int flags, double empty_string_val) {
|
|
StringShape shape(str);
|
|
if (shape.IsSequentialAscii()) {
|
|
const char* begin = SeqAsciiString::cast(str)->GetChars();
|
|
const char* end = begin + str->length();
|
|
return InternalStringToDouble(begin, end, flags, empty_string_val);
|
|
} else if (shape.IsSequentialTwoByte()) {
|
|
const uc16* begin = SeqTwoByteString::cast(str)->GetChars();
|
|
const uc16* end = begin + str->length();
|
|
return InternalStringToDouble(begin, end, flags, empty_string_val);
|
|
} else {
|
|
StringInputBuffer buffer(str);
|
|
return InternalStringToDouble(StringInputBufferIterator(&buffer),
|
|
StringInputBufferIterator::EndMarker(),
|
|
flags,
|
|
empty_string_val);
|
|
}
|
|
}
|
|
|
|
|
|
double StringToInt(String* str, int radix) {
|
|
StringShape shape(str);
|
|
if (shape.IsSequentialAscii()) {
|
|
const char* begin = SeqAsciiString::cast(str)->GetChars();
|
|
const char* end = begin + str->length();
|
|
return InternalStringToInt(begin, end, radix);
|
|
} else if (shape.IsSequentialTwoByte()) {
|
|
const uc16* begin = SeqTwoByteString::cast(str)->GetChars();
|
|
const uc16* end = begin + str->length();
|
|
return InternalStringToInt(begin, end, radix);
|
|
} else {
|
|
StringInputBuffer buffer(str);
|
|
return InternalStringToInt(StringInputBufferIterator(&buffer),
|
|
StringInputBufferIterator::EndMarker(),
|
|
radix);
|
|
}
|
|
}
|
|
|
|
|
|
double StringToDouble(const char* str, int flags, double empty_string_val) {
|
|
const char* end = str + StrLength(str);
|
|
return InternalStringToDouble(str, end, flags, empty_string_val);
|
|
}
|
|
|
|
|
|
double StringToDouble(Vector<const char> str,
|
|
int flags,
|
|
double empty_string_val) {
|
|
const char* end = str.start() + str.length();
|
|
return InternalStringToDouble(str.start(), end, flags, empty_string_val);
|
|
}
|
|
|
|
|
|
const char* DoubleToCString(double v, Vector<char> buffer) {
|
|
StringBuilder builder(buffer.start(), buffer.length());
|
|
|
|
switch (fpclassify(v)) {
|
|
case FP_NAN:
|
|
builder.AddString("NaN");
|
|
break;
|
|
|
|
case FP_INFINITE:
|
|
if (v < 0.0) {
|
|
builder.AddString("-Infinity");
|
|
} else {
|
|
builder.AddString("Infinity");
|
|
}
|
|
break;
|
|
|
|
case FP_ZERO:
|
|
builder.AddCharacter('0');
|
|
break;
|
|
|
|
default: {
|
|
int decimal_point;
|
|
int sign;
|
|
const int kV8DtoaBufferCapacity = kBase10MaximalLength + 1;
|
|
char decimal_rep[kV8DtoaBufferCapacity];
|
|
int length;
|
|
|
|
DoubleToAscii(v, DTOA_SHORTEST, 0,
|
|
Vector<char>(decimal_rep, kV8DtoaBufferCapacity),
|
|
&sign, &length, &decimal_point);
|
|
|
|
if (sign) builder.AddCharacter('-');
|
|
|
|
if (length <= decimal_point && decimal_point <= 21) {
|
|
// ECMA-262 section 9.8.1 step 6.
|
|
builder.AddString(decimal_rep);
|
|
builder.AddPadding('0', decimal_point - length);
|
|
|
|
} else if (0 < decimal_point && decimal_point <= 21) {
|
|
// ECMA-262 section 9.8.1 step 7.
|
|
builder.AddSubstring(decimal_rep, decimal_point);
|
|
builder.AddCharacter('.');
|
|
builder.AddString(decimal_rep + decimal_point);
|
|
|
|
} else if (decimal_point <= 0 && decimal_point > -6) {
|
|
// ECMA-262 section 9.8.1 step 8.
|
|
builder.AddString("0.");
|
|
builder.AddPadding('0', -decimal_point);
|
|
builder.AddString(decimal_rep);
|
|
|
|
} else {
|
|
// ECMA-262 section 9.8.1 step 9 and 10 combined.
|
|
builder.AddCharacter(decimal_rep[0]);
|
|
if (length != 1) {
|
|
builder.AddCharacter('.');
|
|
builder.AddString(decimal_rep + 1);
|
|
}
|
|
builder.AddCharacter('e');
|
|
builder.AddCharacter((decimal_point >= 0) ? '+' : '-');
|
|
int exponent = decimal_point - 1;
|
|
if (exponent < 0) exponent = -exponent;
|
|
builder.AddFormatted("%d", exponent);
|
|
}
|
|
}
|
|
}
|
|
return builder.Finalize();
|
|
}
|
|
|
|
|
|
const char* IntToCString(int n, Vector<char> buffer) {
|
|
bool negative = false;
|
|
if (n < 0) {
|
|
// We must not negate the most negative int.
|
|
if (n == kMinInt) return DoubleToCString(n, buffer);
|
|
negative = true;
|
|
n = -n;
|
|
}
|
|
// Build the string backwards from the least significant digit.
|
|
int i = buffer.length();
|
|
buffer[--i] = '\0';
|
|
do {
|
|
buffer[--i] = '0' + (n % 10);
|
|
n /= 10;
|
|
} while (n);
|
|
if (negative) buffer[--i] = '-';
|
|
return buffer.start() + i;
|
|
}
|
|
|
|
|
|
char* DoubleToFixedCString(double value, int f) {
|
|
const int kMaxDigitsBeforePoint = 21;
|
|
const double kFirstNonFixed = 1e21;
|
|
const int kMaxDigitsAfterPoint = 20;
|
|
ASSERT(f >= 0);
|
|
ASSERT(f <= kMaxDigitsAfterPoint);
|
|
|
|
bool negative = false;
|
|
double abs_value = value;
|
|
if (value < 0) {
|
|
abs_value = -value;
|
|
negative = true;
|
|
}
|
|
|
|
// If abs_value has more than kMaxDigitsBeforePoint digits before the point
|
|
// use the non-fixed conversion routine.
|
|
if (abs_value >= kFirstNonFixed) {
|
|
char arr[100];
|
|
Vector<char> buffer(arr, ARRAY_SIZE(arr));
|
|
return StrDup(DoubleToCString(value, buffer));
|
|
}
|
|
|
|
// Find a sufficiently precise decimal representation of n.
|
|
int decimal_point;
|
|
int sign;
|
|
// Add space for the '\0' byte.
|
|
const int kDecimalRepCapacity =
|
|
kMaxDigitsBeforePoint + kMaxDigitsAfterPoint + 1;
|
|
char decimal_rep[kDecimalRepCapacity];
|
|
int decimal_rep_length;
|
|
DoubleToAscii(value, DTOA_FIXED, f,
|
|
Vector<char>(decimal_rep, kDecimalRepCapacity),
|
|
&sign, &decimal_rep_length, &decimal_point);
|
|
|
|
// Create a representation that is padded with zeros if needed.
|
|
int zero_prefix_length = 0;
|
|
int zero_postfix_length = 0;
|
|
|
|
if (decimal_point <= 0) {
|
|
zero_prefix_length = -decimal_point + 1;
|
|
decimal_point = 1;
|
|
}
|
|
|
|
if (zero_prefix_length + decimal_rep_length < decimal_point + f) {
|
|
zero_postfix_length = decimal_point + f - decimal_rep_length -
|
|
zero_prefix_length;
|
|
}
|
|
|
|
unsigned rep_length =
|
|
zero_prefix_length + decimal_rep_length + zero_postfix_length;
|
|
StringBuilder rep_builder(rep_length + 1);
|
|
rep_builder.AddPadding('0', zero_prefix_length);
|
|
rep_builder.AddString(decimal_rep);
|
|
rep_builder.AddPadding('0', zero_postfix_length);
|
|
char* rep = rep_builder.Finalize();
|
|
|
|
// Create the result string by appending a minus and putting in a
|
|
// decimal point if needed.
|
|
unsigned result_size = decimal_point + f + 2;
|
|
StringBuilder builder(result_size + 1);
|
|
if (negative) builder.AddCharacter('-');
|
|
builder.AddSubstring(rep, decimal_point);
|
|
if (f > 0) {
|
|
builder.AddCharacter('.');
|
|
builder.AddSubstring(rep + decimal_point, f);
|
|
}
|
|
DeleteArray(rep);
|
|
return builder.Finalize();
|
|
}
|
|
|
|
|
|
static char* CreateExponentialRepresentation(char* decimal_rep,
|
|
int exponent,
|
|
bool negative,
|
|
int significant_digits) {
|
|
bool negative_exponent = false;
|
|
if (exponent < 0) {
|
|
negative_exponent = true;
|
|
exponent = -exponent;
|
|
}
|
|
|
|
// Leave room in the result for appending a minus, for a period, the
|
|
// letter 'e', a minus or a plus depending on the exponent, and a
|
|
// three digit exponent.
|
|
unsigned result_size = significant_digits + 7;
|
|
StringBuilder builder(result_size + 1);
|
|
|
|
if (negative) builder.AddCharacter('-');
|
|
builder.AddCharacter(decimal_rep[0]);
|
|
if (significant_digits != 1) {
|
|
builder.AddCharacter('.');
|
|
builder.AddString(decimal_rep + 1);
|
|
int rep_length = StrLength(decimal_rep);
|
|
builder.AddPadding('0', significant_digits - rep_length);
|
|
}
|
|
|
|
builder.AddCharacter('e');
|
|
builder.AddCharacter(negative_exponent ? '-' : '+');
|
|
builder.AddFormatted("%d", exponent);
|
|
return builder.Finalize();
|
|
}
|
|
|
|
|
|
|
|
char* DoubleToExponentialCString(double value, int f) {
|
|
const int kMaxDigitsAfterPoint = 20;
|
|
// f might be -1 to signal that f was undefined in JavaScript.
|
|
ASSERT(f >= -1 && f <= kMaxDigitsAfterPoint);
|
|
|
|
bool negative = false;
|
|
if (value < 0) {
|
|
value = -value;
|
|
negative = true;
|
|
}
|
|
|
|
// Find a sufficiently precise decimal representation of n.
|
|
int decimal_point;
|
|
int sign;
|
|
// f corresponds to the digits after the point. There is always one digit
|
|
// before the point. The number of requested_digits equals hence f + 1.
|
|
// And we have to add one character for the null-terminator.
|
|
const int kV8DtoaBufferCapacity = kMaxDigitsAfterPoint + 1 + 1;
|
|
// Make sure that the buffer is big enough, even if we fall back to the
|
|
// shortest representation (which happens when f equals -1).
|
|
ASSERT(kBase10MaximalLength <= kMaxDigitsAfterPoint + 1);
|
|
char decimal_rep[kV8DtoaBufferCapacity];
|
|
int decimal_rep_length;
|
|
|
|
if (f == -1) {
|
|
DoubleToAscii(value, DTOA_SHORTEST, 0,
|
|
Vector<char>(decimal_rep, kV8DtoaBufferCapacity),
|
|
&sign, &decimal_rep_length, &decimal_point);
|
|
f = decimal_rep_length - 1;
|
|
} else {
|
|
DoubleToAscii(value, DTOA_PRECISION, f + 1,
|
|
Vector<char>(decimal_rep, kV8DtoaBufferCapacity),
|
|
&sign, &decimal_rep_length, &decimal_point);
|
|
}
|
|
ASSERT(decimal_rep_length > 0);
|
|
ASSERT(decimal_rep_length <= f + 1);
|
|
|
|
int exponent = decimal_point - 1;
|
|
char* result =
|
|
CreateExponentialRepresentation(decimal_rep, exponent, negative, f+1);
|
|
|
|
return result;
|
|
}
|
|
|
|
|
|
char* DoubleToPrecisionCString(double value, int p) {
|
|
const int kMinimalDigits = 1;
|
|
const int kMaximalDigits = 21;
|
|
ASSERT(p >= kMinimalDigits && p <= kMaximalDigits);
|
|
USE(kMinimalDigits);
|
|
|
|
bool negative = false;
|
|
if (value < 0) {
|
|
value = -value;
|
|
negative = true;
|
|
}
|
|
|
|
// Find a sufficiently precise decimal representation of n.
|
|
int decimal_point;
|
|
int sign;
|
|
// Add one for the terminating null character.
|
|
const int kV8DtoaBufferCapacity = kMaximalDigits + 1;
|
|
char decimal_rep[kV8DtoaBufferCapacity];
|
|
int decimal_rep_length;
|
|
|
|
DoubleToAscii(value, DTOA_PRECISION, p,
|
|
Vector<char>(decimal_rep, kV8DtoaBufferCapacity),
|
|
&sign, &decimal_rep_length, &decimal_point);
|
|
ASSERT(decimal_rep_length <= p);
|
|
|
|
int exponent = decimal_point - 1;
|
|
|
|
char* result = NULL;
|
|
|
|
if (exponent < -6 || exponent >= p) {
|
|
result =
|
|
CreateExponentialRepresentation(decimal_rep, exponent, negative, p);
|
|
} else {
|
|
// Use fixed notation.
|
|
//
|
|
// Leave room in the result for appending a minus, a period and in
|
|
// the case where decimal_point is not positive for a zero in
|
|
// front of the period.
|
|
unsigned result_size = (decimal_point <= 0)
|
|
? -decimal_point + p + 3
|
|
: p + 2;
|
|
StringBuilder builder(result_size + 1);
|
|
if (negative) builder.AddCharacter('-');
|
|
if (decimal_point <= 0) {
|
|
builder.AddString("0.");
|
|
builder.AddPadding('0', -decimal_point);
|
|
builder.AddString(decimal_rep);
|
|
builder.AddPadding('0', p - decimal_rep_length);
|
|
} else {
|
|
const int m = Min(decimal_rep_length, decimal_point);
|
|
builder.AddSubstring(decimal_rep, m);
|
|
builder.AddPadding('0', decimal_point - decimal_rep_length);
|
|
if (decimal_point < p) {
|
|
builder.AddCharacter('.');
|
|
const int extra = negative ? 2 : 1;
|
|
if (decimal_rep_length > decimal_point) {
|
|
const int len = StrLength(decimal_rep + decimal_point);
|
|
const int n = Min(len, p - (builder.position() - extra));
|
|
builder.AddSubstring(decimal_rep + decimal_point, n);
|
|
}
|
|
builder.AddPadding('0', extra + (p - builder.position()));
|
|
}
|
|
}
|
|
result = builder.Finalize();
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
|
|
char* DoubleToRadixCString(double value, int radix) {
|
|
ASSERT(radix >= 2 && radix <= 36);
|
|
|
|
// Character array used for conversion.
|
|
static const char chars[] = "0123456789abcdefghijklmnopqrstuvwxyz";
|
|
|
|
// Buffer for the integer part of the result. 1024 chars is enough
|
|
// for max integer value in radix 2. We need room for a sign too.
|
|
static const int kBufferSize = 1100;
|
|
char integer_buffer[kBufferSize];
|
|
integer_buffer[kBufferSize - 1] = '\0';
|
|
|
|
// Buffer for the decimal part of the result. We only generate up
|
|
// to kBufferSize - 1 chars for the decimal part.
|
|
char decimal_buffer[kBufferSize];
|
|
decimal_buffer[kBufferSize - 1] = '\0';
|
|
|
|
// Make sure the value is positive.
|
|
bool is_negative = value < 0.0;
|
|
if (is_negative) value = -value;
|
|
|
|
// Get the integer part and the decimal part.
|
|
double integer_part = floor(value);
|
|
double decimal_part = value - integer_part;
|
|
|
|
// Convert the integer part starting from the back. Always generate
|
|
// at least one digit.
|
|
int integer_pos = kBufferSize - 2;
|
|
do {
|
|
integer_buffer[integer_pos--] =
|
|
chars[static_cast<int>(modulo(integer_part, radix))];
|
|
integer_part /= radix;
|
|
} while (integer_part >= 1.0);
|
|
// Sanity check.
|
|
ASSERT(integer_pos > 0);
|
|
// Add sign if needed.
|
|
if (is_negative) integer_buffer[integer_pos--] = '-';
|
|
|
|
// Convert the decimal part. Repeatedly multiply by the radix to
|
|
// generate the next char. Never generate more than kBufferSize - 1
|
|
// chars.
|
|
//
|
|
// TODO(1093998): We will often generate a full decimal_buffer of
|
|
// chars because hitting zero will often not happen. The right
|
|
// solution would be to continue until the string representation can
|
|
// be read back and yield the original value. To implement this
|
|
// efficiently, we probably have to modify dtoa.
|
|
int decimal_pos = 0;
|
|
while ((decimal_part > 0.0) && (decimal_pos < kBufferSize - 1)) {
|
|
decimal_part *= radix;
|
|
decimal_buffer[decimal_pos++] =
|
|
chars[static_cast<int>(floor(decimal_part))];
|
|
decimal_part -= floor(decimal_part);
|
|
}
|
|
decimal_buffer[decimal_pos] = '\0';
|
|
|
|
// Compute the result size.
|
|
int integer_part_size = kBufferSize - 2 - integer_pos;
|
|
// Make room for zero termination.
|
|
unsigned result_size = integer_part_size + decimal_pos;
|
|
// If the number has a decimal part, leave room for the period.
|
|
if (decimal_pos > 0) result_size++;
|
|
// Allocate result and fill in the parts.
|
|
StringBuilder builder(result_size + 1);
|
|
builder.AddSubstring(integer_buffer + integer_pos + 1, integer_part_size);
|
|
if (decimal_pos > 0) builder.AddCharacter('.');
|
|
builder.AddSubstring(decimal_buffer, decimal_pos);
|
|
return builder.Finalize();
|
|
}
|
|
|
|
|
|
} } // namespace v8::internal
|
|
|