Bug 1465808 - Update double-conversion to latest upstream. rs=froydnj

--HG--
extra : rebase_source : 89aeedf516a89aa5d6189bdbde8d1466e59f01f6

mfbt/double-conversion/GIT-INFO

@@ -1,37 +1,9 @@
-commit 1b5fa314800a0e68e2b5d00d17e87a5b1fa3ac5d
-Author: Shane <sffc@sffc1.com>
-Date:   Fri Mar 2 01:26:53 2018 -0800
+commit 9a8e518bedcf171d99eb1c00eef4beb1ecc20a4b
+Merge: ae9ad90 da420c3
+Author: Florian Loitsch <floitsch@google.com>
+Date:   Tue May 22 11:24:13 2018 +0200
 
-    Clarify output charset in DoubleToAscii documentation (#61)
+    Merge pull request #68 from floitschG/static_size_assert
     
-    * Clarify output charset in DoubleToAscii documentation
-    
-    * Fixing typo in charset docs.
+    Use `static_assert` with newer compilers.
 
-diff --git a/double-conversion/double-conversion.h b/double-conversion/double-conversion.h
-index 9978bde..1ccd7fc 100644
---- a/double-conversion/double-conversion.h
-+++ b/double-conversion/double-conversion.h
-@@ -294,13 +294,18 @@ class DoubleToStringConverter {
-   // should be at least kBase10MaximalLength + 1 characters long.
-   static const int kBase10MaximalLength = 17;
- 
--  // Converts the given double 'v' to ascii. 'v' must not be NaN, +Infinity, or
--  // -Infinity. In SHORTEST_SINGLE-mode this restriction also applies to 'v'
--  // after it has been casted to a single-precision float. That is, in this
--  // mode static_cast<float>(v) must not be NaN, +Infinity or -Infinity.
-+  // Converts the given double 'v' to digit characters. 'v' must not be NaN,
-+  // +Infinity, or -Infinity. In SHORTEST_SINGLE-mode this restriction also
-+  // applies to 'v' after it has been casted to a single-precision float. That
-+  // is, in this mode static_cast<float>(v) must not be NaN, +Infinity or
-+  // -Infinity.
-   //
-   // The result should be interpreted as buffer * 10^(point-length).
-   //
-+  // The digits are written to the buffer in the platform's charset, which is
-+  // often UTF-8 (with ASCII-range digits) but may be another charset, such
-+  // as EBCDIC.
-+  //
-   // The output depends on the given mode:
-   //  - SHORTEST: produce the least amount of digits for which the internal
-   //   identity requirement is still satisfied. If the digits are printed

mfbt/double-conversion/double-conversion/double-conversion.cc

@@ -890,9 +890,11 @@ double StringToDoubleConverter::StringToIeee(
   if (*current == 'e' || *current == 'E') {
     if (octal && !allow_trailing_junk) return junk_string_value_;
     if (octal) goto parsing_done;
+    Iterator junk_begin = current;
     ++current;
     if (current == end) {
       if (allow_trailing_junk) {
+        current = junk_begin;
         goto parsing_done;
       } else {
         return junk_string_value_;
@@ -904,6 +906,7 @@ double StringToDoubleConverter::StringToIeee(
       ++current;
       if (current == end) {
         if (allow_trailing_junk) {
+          current = junk_begin;
           goto parsing_done;
         } else {
           return junk_string_value_;
@@ -913,6 +916,7 @@ double StringToDoubleConverter::StringToIeee(
 
     if (current == end || *current < '0' || *current > '9') {
       if (allow_trailing_junk) {
+        current = junk_begin;
         goto parsing_done;
       } else {
         return junk_string_value_;

mfbt/double-conversion/double-conversion/strtod.cc

@@ -472,6 +472,30 @@ double Strtod(Vector<const char> buffer, int exponent) {
   }
 }
 
+static float SanitizedDoubletof(double d) {
+  ASSERT(d >= 0.0);
+  // ASAN has a sanitize check that disallows casting doubles to floats if
+  // they are too big.
+  // https://clang.llvm.org/docs/UndefinedBehaviorSanitizer.html#available-checks
+  // The behavior should be covered by IEEE 754, but some projects use this
+  // flag, so work around it.
+  float max_finite = 3.4028234663852885981170418348451692544e+38;
+  // The half-way point between the max-finite and infinity value.
+  // Since infinity has an even significand everything equal or greater than
+  // this value should become infinity.
+  double half_max_finite_infinity =
+      3.40282356779733661637539395458142568448e+38;
+  if (d >= max_finite) {
+    if (d >= half_max_finite_infinity) {
+      return Single::Infinity();
+    } else {
+      return max_finite;
+    }
+  } else {
+    return static_cast<float>(d);
+  }
+}
+
 float Strtof(Vector<const char> buffer, int exponent) {
   char copy_buffer[kMaxSignificantDecimalDigits];
   Vector<const char> trimmed;
@@ -483,7 +507,7 @@ float Strtof(Vector<const char> buffer, int exponent) {
   double double_guess;
   bool is_correct = ComputeGuess(trimmed, exponent, &double_guess);
 
-  float float_guess = static_cast<float>(double_guess);
+  float float_guess = SanitizedDoubletof(double_guess);
   if (float_guess == double_guess) {
     // This shortcut triggers for integer values.
     return float_guess;
@@ -506,15 +530,15 @@ float Strtof(Vector<const char> buffer, int exponent) {
   double double_next = Double(double_guess).NextDouble();
   double double_previous = Double(double_guess).PreviousDouble();
 
-  float f1 = static_cast<float>(double_previous);
+  float f1 = SanitizedDoubletof(double_previous);
   float f2 = float_guess;
-  float f3 = static_cast<float>(double_next);
+  float f3 = SanitizedDoubletof(double_next);
   float f4;
   if (is_correct) {
     f4 = f3;
   } else {
     double double_next2 = Double(double_next).NextDouble();
-    f4 = static_cast<float>(double_next2);
+    f4 = SanitizedDoubletof(double_next2);
   }
   (void) f2;  // Mark variable as used.
   ASSERT(f1 <= f2 && f2 <= f3 && f3 <= f4);
@@ -529,7 +553,7 @@ float Strtof(Vector<const char> buffer, int exponent) {
          (f1 == f2 && f2 != f3 && f3 == f4) ||
          (f1 == f2 && f2 == f3 && f3 != f4));
 
-  // guess and next are the two possible canditates (in the same way that
+  // guess and next are the two possible candidates (in the same way that
   // double_guess was the lower candidate for a double-precision guess).
   float guess = f1;
   float next = f4;

mfbt/double-conversion/double-conversion/utils.h

@@ -79,7 +79,8 @@ inline void abort_noreturn() { MOZ_CRASH(); }
     defined(__AARCH64EL__) || defined(__aarch64__) || \
     defined(__riscv)
 #define DOUBLE_CONVERSION_CORRECT_DOUBLE_OPERATIONS 1
-#elif defined(__mc68000__)
+#elif defined(__mc68000__) || \
+    defined(__pnacl__) || defined(__native_client__)
 #undef DOUBLE_CONVERSION_CORRECT_DOUBLE_OPERATIONS
 #elif defined(_M_IX86) || defined(__i386__) || defined(__i386)
 #if defined(_WIN32)
@@ -92,12 +93,6 @@ inline void abort_noreturn() { MOZ_CRASH(); }
 #error Target architecture was not detected as supported by Double-Conversion.
 #endif
 
-#if defined(__GNUC__)
-#define DOUBLE_CONVERSION_UNUSED __attribute__((unused))
-#else
-#define DOUBLE_CONVERSION_UNUSED
-#endif
-
 #if defined(_WIN32) && !defined(__MINGW32__)
 
 typedef signed char int8_t;
@@ -324,8 +319,12 @@ template <class Dest, class Source>
 inline Dest BitCast(const Source& source) {
   // Compile time assertion: sizeof(Dest) == sizeof(Source)
   // A compile error here means your Dest and Source have different sizes.
-  DOUBLE_CONVERSION_UNUSED
-      typedef char VerifySizesAreEqual[sizeof(Dest) == sizeof(Source) ? 1 : -1];
+#if __cplusplus >= 201103L
+  static_assert(sizeof(Dest) == sizeof(Source),
+                "source and destination size mismatch");
+#else
+  typedef char VerifySizesAreEqual[sizeof(Dest) == sizeof(Source) ? 1 : -1];
+#endif
 
   Dest dest;
   memmove(&dest, &source, sizeof(dest));