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
61void DOUBLE_CONVERSION_NO_RETURN abort_noreturn();
62inline 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
91double Div_double(double x, double y) { return x / y; }
92
93// -- in main.c
94double Div_double(double x, double y); // Forward declaration.
95
96int 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
133typedef signed char int8_t;
134typedef unsigned char uint8_t;
135typedef short int16_t; // NOLINT
136typedef unsigned short uint16_t; // NOLINT
137typedef int int32_t;
138typedef unsigned int uint32_t;
139typedef __int64 int64_t;
140typedef 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
149typedef 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
188U_NAMESPACE_BEGIN
189
190namespace double_conversion {
191
192inline 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.
199template <typename T>
200class Vector {
201 public:
202 Vector() : start_(NULL), length_(0) {}
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'.
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.
217 int length() const { return length_; }
218
219 // Returns whether or not the vector is empty.
220 bool is_empty() const { return length_ == 0; }
221
222 // Returns the pointer to the start of the data in the vector.
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
231 T& first() { return start_[0]; }
232
233 T& last() { return start_[length_ - 1]; }
234
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.
249class StringBuilder {
250 public:
251 StringBuilder(char* buffer, int buffer_size)
252 : buffer_(buffer, buffer_size), position_(0) { }
253
254 ~StringBuilder() { if (!is_finalized()) Finalize(); }
255
256 int size() const { return buffer_.length(); }
257
258 // Get the current position in the builder.
259 int position() const {
260 DOUBLE_CONVERSION_ASSERT(!is_finalized());
261 return position_;
262 }
263
264 // Reset the position.
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.
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.
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.
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.
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.
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
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.
345template <class Dest, class Source>
346Dest 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
362template <class Dest, class Source>
363Dest 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
370U_NAMESPACE_END
371
372#endif // DOUBLE_CONVERSION_UTILS_H_
373#endif // ICU PATCH: close #if !UCONFIG_NO_FORMATTING
374