Revert revisions 4241, 4243 and 4247 because of Windows build errors...

src/conversions.cc

Index: src/conversions.cc
===================================================================
--- src/conversions.cc	(revision 4248)
+++ src/conversions.cc	(working copy)
@@ -26,7 +26,6 @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include <stdarg.h>
-#include <limits.h>
 
 #include "v8.h"
 
@@ -93,66 +92,74 @@
 }
 
 
-namespace {
+static inline void ReleaseCString(const char* original, const char* str) {
+}
 
-// C++-style iterator adaptor for StringInputBuffer
-// (unlike C++ iterators the end-marker has different type).
-class StringInputBufferIterator {
- public:
-  class EndMarker {};
 
-  explicit StringInputBufferIterator(StringInputBuffer* buffer);
+static inline void ReleaseCString(String* original, const char* str) {
+  DeleteArray(const_cast<char *>(str));
+}
 
-  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_;
-};
+static inline bool IsSpace(const char* str, int index) {
+  ASSERT(index >= 0 && index < StrLength(str));
+  return Scanner::kIsWhiteSpace.get(str[index]);
+}
 
 
-StringInputBufferIterator::StringInputBufferIterator(
-    StringInputBuffer* buffer) : buffer_(buffer) {
-  ++(*this);
+static inline bool IsSpace(String* str, int index) {
+  return Scanner::kIsWhiteSpace.get(str->Get(index));
 }
 
-int StringInputBufferIterator::operator*() const {
-  return current_;
-}
 
-
-void StringInputBufferIterator::operator++() {
-  end_ = !buffer_->has_more();
-  if (!end_) {
-    current_ = buffer_->GetNext();
-  }
+static inline bool SubStringEquals(const char* str,
+                                   int index,
+                                   const char* other) {
+  return strncmp(str + index, other, strlen(other)) != 0;
 }
-}
 
 
-static inline void ReleaseCString(const char* original, const char* str) {
+static inline bool SubStringEquals(String* str, int index, const char* other) {
+  HandleScope scope;
+  int str_length = str->length();
+  int other_length = StrLength(other);
+  int end = index + other_length < str_length ?
+            index + other_length :
+            str_length;
+  Handle<String> substring =
+      Factory::NewSubString(Handle<String>(str), index, end);
+  return substring->IsEqualTo(Vector<const char>(other, other_length));
 }
 
 
-static inline void ReleaseCString(String* original, const char* str) {
-  DeleteArray(const_cast<char *>(str));
-}
+// Check if a string should be parsed as an octal number.  The string
+// can be either a char* or a String*.
+template<class S>
+static bool ShouldParseOctal(S* s, int i) {
+  int index = i;
+  int len = GetLength(s);
+  if (index < len && GetChar(s, index) != '0') return false;
 
+  // If the first real character (following '0') is not an octal
+  // digit, bail out early. This also takes care of numbers of the
+  // forms 0.xxx and 0exxx by not allowing the first 0 to be
+  // interpreted as an octal.
+  index++;
+  if (index < len) {
+    int d = GetChar(s, index) - '0';
+    if (d < 0 || d > 7) return false;
+  } else {
+    return false;
+  }
 
-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;
+  // Traverse all digits (including the first). If there is an octal
+  // prefix which is not a part of a longer decimal prefix, we return
+  // true. Otherwise, false is returned.
+  while (index < len) {
+    int d = GetChar(s, index++) - '0';
+    if (d == 8 || d == 9) return false;
+    if (d <  0 || d >  7) return true;
   }
-  ++*current;
   return true;
 }
 
@@ -255,364 +262,95 @@
 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 (!Scanner::kIsWhiteSpace.get(**current)) return true;
-    ++*current;
-  }
-  return false;
-}
-
-
-template <class Iterator, class EndMark>
-static double InternalHexidecimalStringToDouble(Iterator current,
-                                                EndMark end,
-                                                char* buffer,
-                                                bool allow_trailing_junk) {
-  ASSERT(current != end);
-  // We reuse the buffer of InternalStringToDouble. Since hexidecimal
-  // numbers may have much less digits than decimal the buffer won't overflow.
-  int significant_digits = 0;
-  int insignificant_digits = 0;
-  bool leading_zero = false;
-  // Hexidecomal may have (52) / 4 + 1 significant digit. Mean of 2
-  // hexidecimal may have n + 1.
-  const int max_significant_digits = (52) / 4 + 2;
-  int buffer_pos = 0;
-  bool nonzero_digit_dropped = false;
-
-  // Skip leading 0s.
-  while (*current == '0') {
-    leading_zero = true;
-    ++current;
-    if (current == end) return 0;
-  }
-
-  int begin_pos = buffer_pos;
-  while ((*current >= '0' && *current <= '9')
-         || (*current >= 'a' && *current <= 'f')
-         || (*current >= 'A' && *current <= 'F')) {
-    if (significant_digits <= max_significant_digits) {
-      buffer[buffer_pos++] = static_cast<char>(*current);
-      significant_digits++;
-    } else {
-      insignificant_digits++;
-      nonzero_digit_dropped = nonzero_digit_dropped || *current != '0';
-    }
-    ++current;
-    if (current == end) break;
-  }
-
-  if (!allow_trailing_junk && AdvanceToNonspace(&current, end)) {
-    return JUNK_STRING_VALUE;
-  }
-
-  if (significant_digits == 0) {
-    return leading_zero ? 0 : JUNK_STRING_VALUE;
-  }
-
-  if (nonzero_digit_dropped) {
-    ASSERT(insignificant_digits > 0);
-    insignificant_digits--;
-    buffer[buffer_pos++] = '1';
-  }
-
-  buffer[buffer_pos] = '\0';
-
-  double result;
-  StringToInt(buffer, begin_pos, 16, &result);
-  if (insignificant_digits > 0) {
-    // Multiplying by power of 2 doesn't cause a loss of precision.
-    result *= pow(16.0, insignificant_digits);
-  }
-  return result;
-}
-
-
-// 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,
+// Convert a string to a double value.  The string can be either a
+// char* or a String*.
+template<class S>
+static double InternalStringToDouble(S* str,
                                      int flags,
                                      double empty_string_val) {
-  // To make sure that iterator unreferencing 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 unreferenced after the 'parsing_done' label.
-  // 5. Code before 'parsing_done' may rely on 'current != end'.
-  if (!AdvanceToNonspace(&current, end)) return empty_string_val;
+  double result = 0.0;
+  int index = 0;
 
-  const bool allow_trailing_junk = (flags & ALLOW_TRAILING_JUNK) != 0;
+  int len = GetLength(str);
 
-  // Insignificant digits will be removed.
-  const int max_significant_digits = 772;
-  // The longest form of simplified number is: "-<significant digits>'.1eXXX\0".
-  const int buffer_size = max_significant_digits + 10;
-  char buffer[buffer_size];  // NOLINT: size is known at compile time.
-  int buffer_pos = 0;
+  // Skip leading spaces.
+  while ((index < len) && IsSpace(str, index)) index++;
 
-  // 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;
+  // Is the string empty?
+  if (index >= len) return empty_string_val;
 
-  double signed_zero = 0.0;
+  // Get the first character.
+  uint16_t first = GetChar(str, index);
 
-  if (*current == '+') {
-    // Ignore leading sign; Skip following spaces.
-    ++current;
-    if (!AdvanceToNonspace(&current, end)) return JUNK_STRING_VALUE;
-  } else if (*current == '-') {
-    buffer[buffer_pos++] = '-';
-    ++current;
-    if (!AdvanceToNonspace(&current, end)) return JUNK_STRING_VALUE;
-    signed_zero = -0.0;
+  // Numbers can only start with '-', '+', '.', 'I' (Infinity), or a digit.
+  if (first != '-' && first != '+' && first != '.' && first != 'I' &&
+      (first > '9' || first < '0')) {
+    return JUNK_STRING_VALUE;
   }
 
-  static const char infinity_symbol[] = "Infinity";
-  if (*current == infinity_symbol[0]) {
-    if (!SubStringEquals(&current, end, infinity_symbol)) {
-      return JUNK_STRING_VALUE;
-    }
-
-    if (!allow_trailing_junk && AdvanceToNonspace(&current, end)) {
-      return JUNK_STRING_VALUE;
-    }
-
-    return (buffer_pos > 0 && buffer[0] == '-') ? -V8_INFINITY : V8_INFINITY;
+  // Compute sign of result based on first character.
+  int sign = 1;
+  if (first == '-') {
+    sign = -1;
+    index++;
+    // String only containing a '-' are junk chars.
+    if (index == len) return JUNK_STRING_VALUE;
   }
 
-  bool leading_zero = false;
-  if (*current == '0') {
-    ++current;
-    if (current == end) return signed_zero;
-
-    leading_zero = true;
-
-    // It could be hexadecimal value.
-    if ((flags & ALLOW_HEX) && (*current == 'x' || *current == 'X')) {
-      ++current;
-      if (current == end) return JUNK_STRING_VALUE;  // "0x".
-
-      double result = InternalHexidecimalStringToDouble(current,
-                                                        end,
-                                                        buffer + buffer_pos,
-                                                        allow_trailing_junk);
-      return (buffer_pos > 0 && buffer[0] == '-') ? -result : result;
-    }
-
-    // Ignore leading zeros in the integer part.
-    while (*current == '0') {
-      ++current;
-      if (current == end) return signed_zero;
-    }
-  }
-
-  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 < max_significant_digits) {
-      ASSERT(buffer_pos < buffer_size);
-      buffer[buffer_pos++] = static_cast<char>(*current);
-      significant_digits++;
-      // Will later check if it's an octal in the buffer.
+  // do we have a hex number?
+  // (since the string is 0-terminated, it's ok to look one char beyond the end)
+  if ((flags & ALLOW_HEX) != 0 &&
+      (index + 1) < len &&
+      GetChar(str, index) == '0' &&
+      (GetChar(str, index + 1) == 'x' || GetChar(str, index + 1) == 'X')) {
+    index += 2;
+    index = StringToInt(str, index, 16, &result);
+  } else if ((flags & ALLOW_OCTALS) != 0 && ShouldParseOctal(str, index)) {
+    // NOTE: We optimistically try to parse the number as an octal (if
+    // we're allowed to), even though this is not as dictated by
+    // ECMA-262. The reason for doing this is compatibility with IE and
+    // Firefox.
+    index = StringToInt(str, index, 8, &result);
+  } else {
+    const char* cstr = GetCString(str, index);
+    const char* end;
+    // Optimistically parse the number and then, if that fails,
+    // check if it might have been {+,-,}Infinity.
+    result = gay_strtod(cstr, &end);
+    ReleaseCString(str, cstr);
+    if (result != 0.0 || end != cstr) {
+      // It appears that strtod worked
+      index += static_cast<int>(end - cstr);
     } 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 (*current == '.') {
-    ASSERT(buffer_pos < buffer_size);
-    ++current;
-    if (current == end) {
-      if (significant_digits == 0 && !leading_zero) {
+      // Check for {+,-,}Infinity
+      bool is_negative = (GetChar(str, index) == '-');
+      if (GetChar(str, index) == '+' || GetChar(str, index) == '-')
+        index++;
+      if (!SubStringEquals(str, index, "Infinity"))
         return JUNK_STRING_VALUE;
-      } else {
-        goto parsing_done;
-      }
+      result = is_negative ? -V8_INFINITY : V8_INFINITY;
+      index += 8;
     }
-    buffer[buffer_pos++] = '.';
-
-    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 signed_zero;
-        exponent--;  // Move this 0 into the exponent.
-      }
-    }
-
-    // There is the fractional part.
-    while (*current >= '0' && *current <= '9') {
-      if (significant_digits < max_significant_digits) {
-        ASSERT(buffer_pos < buffer_size);
-        buffer[buffer_pos++] = static_cast<char>(*current);
-        significant_digits++;
-      } 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 is no digits in the string.
-    return JUNK_STRING_VALUE;
+  if ((flags & ALLOW_TRAILING_JUNK) == 0) {
+    // skip trailing spaces
+    while ((index < len) && IsSpace(str, index)) index++;
+    // string ending with junk?
+    if (index < len) 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(&current, end)) {
-    return JUNK_STRING_VALUE;
-  }
-
-  parsing_done:
-  exponent += insignificant_digits;
-
-  if (octal) {
-    buffer[buffer_pos] = '\0';
-    // ALLOW_OCTALS has set and there is no '8' and '9' in insignificant
-    // digits. Check significant digits now.
-    char sign = '+';
-    const char* s = buffer;
-    if (*s == '-' || *s == '+') sign = *s++;
-
-    double result;
-    s += StringToInt(s, 0, 8, &result);
-    if (!allow_trailing_junk && *s != '\0') return JUNK_STRING_VALUE;
-
-    if (sign == '-') result = -result;
-    if (insignificant_digits > 0) {
-      result *= pow(8.0, insignificant_digits);
-    }
-    return result;
-  }
-
-  if (nonzero_digit_dropped) {
-    if (insignificant_digits > 0) buffer[buffer_pos++] = '.';
-    buffer[buffer_pos++] = '1';
-  }
-
-  if (exponent != 0) {
-    ASSERT(buffer_pos < buffer_size);
-    buffer[buffer_pos++] = 'e';
-    if (exponent < 0) {
-      ASSERT(buffer_pos < buffer_size);
-      buffer[buffer_pos++] = '-';
-      exponent = -exponent;
-    }
-    if (exponent > 999) exponent = 999;  // Result will be Infinity or 0 or -0.
-
-    const int exp_digits = 3;
-    for (int i = 0; i < exp_digits; i++) {
-      buffer[buffer_pos + exp_digits - 1 - i] = '0' + exponent % 10;
-      exponent /= 10;
-    }
-    ASSERT(exponent == 0);
-    buffer_pos += exp_digits;
-  }
-
-  ASSERT(buffer_pos < buffer_size);
-  buffer[buffer_pos] = '\0';
-
-  return gay_strtod(buffer, NULL);
+  return sign * result;
 }
 
+
 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);
-  }
+  return InternalStringToDouble(str, flags, empty_string_val);
 }
 
 
 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);
+  return InternalStringToDouble(str, flags, empty_string_val);
 }