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1 // © 2018 and later: Unicode, Inc. and others.
2 // License & terms of use: http://www.unicode.org/copyright.html
3 //
4 // From the double-conversion library. Original license:
5 //
6 // Copyright 2010 the V8 project authors. All rights reserved.
7 // Redistribution and use in source and binary forms, with or without
8 // modification, are permitted provided that the following conditions are
9 // met:
10 //
11 //     * Redistributions of source code must retain the above copyright
12 //       notice, this list of conditions and the following disclaimer.
13 //     * Redistributions in binary form must reproduce the above
14 //       copyright notice, this list of conditions and the following
15 //       disclaimer in the documentation and/or other materials provided
16 //       with the distribution.
17 //     * Neither the name of Google Inc. nor the names of its
18 //       contributors may be used to endorse or promote products derived
19 //       from this software without specific prior written permission.
20 //
21 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 
33 // ICU PATCH: ifdef around UCONFIG_NO_FORMATTING
34 #include "unicode/utypes.h"
35 #if !UCONFIG_NO_FORMATTING
36 
37 #ifndef DOUBLE_CONVERSION_UTILS_H_
38 #define DOUBLE_CONVERSION_UTILS_H_
39 
40 #include <cstdlib>
41 #include <cstring>
42 
43 // ICU PATCH: Use U_ASSERT instead of <assert.h>
44 #include "uassert.h"
45 #ifndef DOUBLE_CONVERSION_ASSERT
46 #define DOUBLE_CONVERSION_ASSERT(condition)         \
47     U_ASSERT(condition);
48 #endif
49 #ifndef DOUBLE_CONVERSION_UNIMPLEMENTED
50 #define DOUBLE_CONVERSION_UNIMPLEMENTED() (abort())
51 #endif
52 #ifndef DOUBLE_CONVERSION_NO_RETURN
53 #ifdef _MSC_VER
54 #define DOUBLE_CONVERSION_NO_RETURN __declspec(noreturn)
55 #else
56 #define DOUBLE_CONVERSION_NO_RETURN __attribute__((noreturn))
57 #endif
58 #endif
59 #ifndef DOUBLE_CONVERSION_UNREACHABLE
60 #ifdef _MSC_VER
61 void DOUBLE_CONVERSION_NO_RETURN abort_noreturn();
abort_noreturn()62 inline void abort_noreturn() { abort(); }
63 #define DOUBLE_CONVERSION_UNREACHABLE()   (abort_noreturn())
64 #else
65 #define DOUBLE_CONVERSION_UNREACHABLE()   (abort())
66 #endif
67 #endif
68 
69 #ifndef DOUBLE_CONVERSION_UNUSED
70 #ifdef __GNUC__
71 #define DOUBLE_CONVERSION_UNUSED __attribute__((unused))
72 #else
73 #define DOUBLE_CONVERSION_UNUSED
74 #endif
75 #endif
76 
77 // Double operations detection based on target architecture.
78 // Linux uses a 80bit wide floating point stack on x86. This induces double
79 // rounding, which in turn leads to wrong results.
80 // An easy way to test if the floating-point operations are correct is to
81 // evaluate: 89255.0/1e22. If the floating-point stack is 64 bits wide then
82 // the result is equal to 89255e-22.
83 // The best way to test this, is to create a division-function and to compare
84 // the output of the division with the expected result. (Inlining must be
85 // disabled.)
86 // On Linux,x86 89255e-22 != Div_double(89255.0/1e22)
87 //
88 // For example:
89 /*
90 // -- in div.c
91 double Div_double(double x, double y) { return x / y; }
92 
93 // -- in main.c
94 double Div_double(double x, double y);  // Forward declaration.
95 
96 int main(int argc, char** argv) {
97   return Div_double(89255.0, 1e22) == 89255e-22;
98 }
99 */
100 // Run as follows ./main || echo "correct"
101 //
102 // If it prints "correct" then the architecture should be here, in the "correct" section.
103 #if defined(_M_X64) || defined(__x86_64__) || \
104     defined(__ARMEL__) || defined(__avr32__) || defined(_M_ARM) || defined(_M_ARM64) || \
105     defined(__hppa__) || defined(__ia64__) || \
106     defined(__mips__) || \
107     defined(__powerpc__) || defined(__ppc__) || defined(__ppc64__) || \
108     defined(_POWER) || defined(_ARCH_PPC) || defined(_ARCH_PPC64) || \
109     defined(__sparc__) || defined(__sparc) || defined(__s390__) || \
110     defined(__SH4__) || defined(__alpha__) || \
111     defined(_MIPS_ARCH_MIPS32R2) || defined(__ARMEB__) ||\
112     defined(__AARCH64EL__) || defined(__aarch64__) || defined(__AARCH64EB__) || \
113     defined(__riscv) || defined(__e2k__) || \
114     defined(__or1k__) || defined(__arc__) || \
115     defined(__EMSCRIPTEN__)
116 #define DOUBLE_CONVERSION_CORRECT_DOUBLE_OPERATIONS 1
117 #elif defined(__mc68000__) || \
118     defined(__pnacl__) || defined(__native_client__)
119 #undef DOUBLE_CONVERSION_CORRECT_DOUBLE_OPERATIONS
120 #elif defined(_M_IX86) || defined(__i386__) || defined(__i386)
121 #if defined(_WIN32)
122 // Windows uses a 64bit wide floating point stack.
123 #define DOUBLE_CONVERSION_CORRECT_DOUBLE_OPERATIONS 1
124 #else
125 #undef DOUBLE_CONVERSION_CORRECT_DOUBLE_OPERATIONS
126 #endif  // _WIN32
127 #else
128 #error Target architecture was not detected as supported by Double-Conversion.
129 #endif
130 
131 #if defined(_WIN32) && !defined(__MINGW32__)
132 
133 typedef signed char int8_t;
134 typedef unsigned char uint8_t;
135 typedef short int16_t;  // NOLINT
136 typedef unsigned short uint16_t;  // NOLINT
137 typedef int int32_t;
138 typedef unsigned int uint32_t;
139 typedef __int64 int64_t;
140 typedef unsigned __int64 uint64_t;
141 // intptr_t and friends are defined in crtdefs.h through stdio.h.
142 
143 #else
144 
145 #include <stdint.h>
146 
147 #endif
148 
149 typedef uint16_t uc16;
150 
151 // The following macro works on both 32 and 64-bit platforms.
152 // Usage: instead of writing 0x1234567890123456
153 //      write DOUBLE_CONVERSION_UINT64_2PART_C(0x12345678,90123456);
154 #define DOUBLE_CONVERSION_UINT64_2PART_C(a, b) (((static_cast<uint64_t>(a) << 32) + 0x##b##u))
155 
156 
157 // The expression DOUBLE_CONVERSION_ARRAY_SIZE(a) is a compile-time constant of type
158 // size_t which represents the number of elements of the given
159 // array. You should only use DOUBLE_CONVERSION_ARRAY_SIZE on statically allocated
160 // arrays.
161 #ifndef DOUBLE_CONVERSION_ARRAY_SIZE
162 #define DOUBLE_CONVERSION_ARRAY_SIZE(a)                                   \
163   ((sizeof(a) / sizeof(*(a))) /                         \
164   static_cast<size_t>(!(sizeof(a) % sizeof(*(a)))))
165 #endif
166 
167 // A macro to disallow the evil copy constructor and operator= functions
168 // This should be used in the private: declarations for a class
169 #ifndef DOUBLE_CONVERSION_DISALLOW_COPY_AND_ASSIGN
170 #define DOUBLE_CONVERSION_DISALLOW_COPY_AND_ASSIGN(TypeName)      \
171   TypeName(const TypeName&);                    \
172   void operator=(const TypeName&)
173 #endif
174 
175 // A macro to disallow all the implicit constructors, namely the
176 // default constructor, copy constructor and operator= functions.
177 //
178 // This should be used in the private: declarations for a class
179 // that wants to prevent anyone from instantiating it. This is
180 // especially useful for classes containing only static methods.
181 #ifndef DOUBLE_CONVERSION_DISALLOW_IMPLICIT_CONSTRUCTORS
182 #define DOUBLE_CONVERSION_DISALLOW_IMPLICIT_CONSTRUCTORS(TypeName) \
183   TypeName();                                    \
184   DOUBLE_CONVERSION_DISALLOW_COPY_AND_ASSIGN(TypeName)
185 #endif
186 
187 // ICU PATCH: Wrap in ICU namespace
188 U_NAMESPACE_BEGIN
189 
190 namespace double_conversion {
191 
StrLength(const char * string)192 inline int StrLength(const char* string) {
193   size_t length = strlen(string);
194   DOUBLE_CONVERSION_ASSERT(length == static_cast<size_t>(static_cast<int>(length)));
195   return static_cast<int>(length);
196 }
197 
198 // This is a simplified version of V8's Vector class.
199 template <typename T>
200 class Vector {
201  public:
Vector()202   Vector() : start_(NULL), length_(0) {}
Vector(T * data,int len)203   Vector(T* data, int len) : start_(data), length_(len) {
204     DOUBLE_CONVERSION_ASSERT(len == 0 || (len > 0 && data != NULL));
205   }
206 
207   // Returns a vector using the same backing storage as this one,
208   // spanning from and including 'from', to but not including 'to'.
SubVector(int from,int to)209   Vector<T> SubVector(int from, int to) {
210     DOUBLE_CONVERSION_ASSERT(to <= length_);
211     DOUBLE_CONVERSION_ASSERT(from < to);
212     DOUBLE_CONVERSION_ASSERT(0 <= from);
213     return Vector<T>(start() + from, to - from);
214   }
215 
216   // Returns the length of the vector.
length()217   int length() const { return length_; }
218 
219   // Returns whether or not the vector is empty.
is_empty()220   bool is_empty() const { return length_ == 0; }
221 
222   // Returns the pointer to the start of the data in the vector.
start()223   T* start() const { return start_; }
224 
225   // Access individual vector elements - checks bounds in debug mode.
226   T& operator[](int index) const {
227     DOUBLE_CONVERSION_ASSERT(0 <= index && index < length_);
228     return start_[index];
229   }
230 
first()231   T& first() { return start_[0]; }
232 
last()233   T& last() { return start_[length_ - 1]; }
234 
pop_back()235   void pop_back() {
236     DOUBLE_CONVERSION_ASSERT(!is_empty());
237     --length_;
238   }
239 
240  private:
241   T* start_;
242   int length_;
243 };
244 
245 
246 // Helper class for building result strings in a character buffer. The
247 // purpose of the class is to use safe operations that checks the
248 // buffer bounds on all operations in debug mode.
249 class StringBuilder {
250  public:
StringBuilder(char * buffer,int buffer_size)251   StringBuilder(char* buffer, int buffer_size)
252       : buffer_(buffer, buffer_size), position_(0) { }
253 
~StringBuilder()254   ~StringBuilder() { if (!is_finalized()) Finalize(); }
255 
size()256   int size() const { return buffer_.length(); }
257 
258   // Get the current position in the builder.
position()259   int position() const {
260     DOUBLE_CONVERSION_ASSERT(!is_finalized());
261     return position_;
262   }
263 
264   // Reset the position.
Reset()265   void Reset() { position_ = 0; }
266 
267   // Add a single character to the builder. It is not allowed to add
268   // 0-characters; use the Finalize() method to terminate the string
269   // instead.
AddCharacter(char c)270   void AddCharacter(char c) {
271     DOUBLE_CONVERSION_ASSERT(c != '\0');
272     DOUBLE_CONVERSION_ASSERT(!is_finalized() && position_ < buffer_.length());
273     buffer_[position_++] = c;
274   }
275 
276   // Add an entire string to the builder. Uses strlen() internally to
277   // compute the length of the input string.
AddString(const char * s)278   void AddString(const char* s) {
279     AddSubstring(s, StrLength(s));
280   }
281 
282   // Add the first 'n' characters of the given string 's' to the
283   // builder. The input string must have enough characters.
AddSubstring(const char * s,int n)284   void AddSubstring(const char* s, int n) {
285     DOUBLE_CONVERSION_ASSERT(!is_finalized() && position_ + n < buffer_.length());
286     DOUBLE_CONVERSION_ASSERT(static_cast<size_t>(n) <= strlen(s));
287     memmove(&buffer_[position_], s, n);
288     position_ += n;
289   }
290 
291 
292   // Add character padding to the builder. If count is non-positive,
293   // nothing is added to the builder.
AddPadding(char c,int count)294   void AddPadding(char c, int count) {
295     for (int i = 0; i < count; i++) {
296       AddCharacter(c);
297     }
298   }
299 
300   // Finalize the string by 0-terminating it and returning the buffer.
Finalize()301   char* Finalize() {
302     DOUBLE_CONVERSION_ASSERT(!is_finalized() && position_ < buffer_.length());
303     buffer_[position_] = '\0';
304     // Make sure nobody managed to add a 0-character to the
305     // buffer while building the string.
306     DOUBLE_CONVERSION_ASSERT(strlen(buffer_.start()) == static_cast<size_t>(position_));
307     position_ = -1;
308     DOUBLE_CONVERSION_ASSERT(is_finalized());
309     return buffer_.start();
310   }
311 
312  private:
313   Vector<char> buffer_;
314   int position_;
315 
is_finalized()316   bool is_finalized() const { return position_ < 0; }
317 
318   DOUBLE_CONVERSION_DISALLOW_IMPLICIT_CONSTRUCTORS(StringBuilder);
319 };
320 
321 // The type-based aliasing rule allows the compiler to assume that pointers of
322 // different types (for some definition of different) never alias each other.
323 // Thus the following code does not work:
324 //
325 // float f = foo();
326 // int fbits = *(int*)(&f);
327 //
328 // The compiler 'knows' that the int pointer can't refer to f since the types
329 // don't match, so the compiler may cache f in a register, leaving random data
330 // in fbits.  Using C++ style casts makes no difference, however a pointer to
331 // char data is assumed to alias any other pointer.  This is the 'memcpy
332 // exception'.
333 //
334 // Bit_cast uses the memcpy exception to move the bits from a variable of one
335 // type of a variable of another type.  Of course the end result is likely to
336 // be implementation dependent.  Most compilers (gcc-4.2 and MSVC 2005)
337 // will completely optimize BitCast away.
338 //
339 // There is an additional use for BitCast.
340 // Recent gccs will warn when they see casts that may result in breakage due to
341 // the type-based aliasing rule.  If you have checked that there is no breakage
342 // you can use BitCast to cast one pointer type to another.  This confuses gcc
343 // enough that it can no longer see that you have cast one pointer type to
344 // another thus avoiding the warning.
345 template <class Dest, class Source>
BitCast(const Source & source)346 Dest BitCast(const Source& source) {
347   // Compile time assertion: sizeof(Dest) == sizeof(Source)
348   // A compile error here means your Dest and Source have different sizes.
349 #if __cplusplus >= 201103L
350   static_assert(sizeof(Dest) == sizeof(Source),
351                 "source and destination size mismatch");
352 #else
353   DOUBLE_CONVERSION_UNUSED
354   typedef char VerifySizesAreEqual[sizeof(Dest) == sizeof(Source) ? 1 : -1];
355 #endif
356 
357   Dest dest;
358   memmove(&dest, &source, sizeof(dest));
359   return dest;
360 }
361 
362 template <class Dest, class Source>
BitCast(Source * source)363 Dest BitCast(Source* source) {
364   return BitCast<Dest>(reinterpret_cast<uintptr_t>(source));
365 }
366 
367 }  // namespace double_conversion
368 
369 // ICU PATCH: Close ICU namespace
370 U_NAMESPACE_END
371 
372 #endif  // DOUBLE_CONVERSION_UTILS_H_
373 #endif // ICU PATCH: close #if !UCONFIG_NO_FORMATTING
374