xref: /freebsd/contrib/llvm-project/libcxx/src/string.cpp (revision 2e3f49888ec8851bafb22011533217487764fdb0)
1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include <__assert>
10 #include <cerrno>
11 #include <charconv>
12 #include <cstdlib>
13 #include <limits>
14 #include <stdexcept>
15 #include <string>
16 
17 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
18 #  include <cwchar>
19 #endif
20 
21 _LIBCPP_BEGIN_NAMESPACE_STD
22 
23 #ifndef _LIBCPP_ABI_DO_NOT_EXPORT_BASIC_STRING_COMMON
24 
25 template <bool>
26 struct __basic_string_common;
27 
28 // The struct isn't declared anymore in the headers. It's only here for ABI compatibility.
29 template <>
30 struct __basic_string_common<true> {
31     _LIBCPP_NORETURN _LIBCPP_EXPORTED_FROM_ABI void __throw_length_error() const;
32     _LIBCPP_NORETURN _LIBCPP_EXPORTED_FROM_ABI void __throw_out_of_range() const;
33 };
34 
35 void __basic_string_common<true>::__throw_length_error() const {
36     std::__throw_length_error("basic_string");
37 }
38 void __basic_string_common<true>::__throw_out_of_range() const {
39     std::__throw_out_of_range("basic_string");
40 }
41 
42 #endif // _LIBCPP_ABI_DO_NOT_EXPORT_BASIC_STRING_COMMON
43 
44 #define _LIBCPP_EXTERN_TEMPLATE_DEFINE(...) template __VA_ARGS__;
45 #ifdef _LIBCPP_ABI_STRING_OPTIMIZED_EXTERNAL_INSTANTIATION
46     _LIBCPP_STRING_UNSTABLE_EXTERN_TEMPLATE_LIST(_LIBCPP_EXTERN_TEMPLATE_DEFINE, char)
47 #   ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
48         _LIBCPP_STRING_UNSTABLE_EXTERN_TEMPLATE_LIST(_LIBCPP_EXTERN_TEMPLATE_DEFINE, wchar_t)
49 #   endif
50 #else
51     _LIBCPP_STRING_V1_EXTERN_TEMPLATE_LIST(_LIBCPP_EXTERN_TEMPLATE_DEFINE, char)
52 #   ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
53         _LIBCPP_STRING_V1_EXTERN_TEMPLATE_LIST(_LIBCPP_EXTERN_TEMPLATE_DEFINE, wchar_t)
54 #   endif
55 #endif
56 #undef _LIBCPP_EXTERN_TEMPLATE_DEFINE
57 
58 template string operator+<char, char_traits<char>, allocator<char>>(char const*, string const&);
59 
60 namespace
61 {
62 
63 inline void throw_from_string_out_of_range(const string& func) {
64     std::__throw_out_of_range((func + ": out of range").c_str());
65 }
66 
67 inline void throw_from_string_invalid_arg(const string& func) {
68     std::__throw_invalid_argument((func + ": no conversion").c_str());
69 }
70 
71 // as_integer
72 
73 template<typename V, typename S, typename F>
74 inline V as_integer_helper(const string& func, const S& str, size_t* idx, int base, F f) {
75     typename S::value_type* ptr = nullptr;
76     const typename S::value_type* const p = str.c_str();
77     __libcpp_remove_reference_t<decltype(errno)> errno_save = errno;
78     errno = 0;
79     V r = f(p, &ptr, base);
80     swap(errno, errno_save);
81     if (errno_save == ERANGE)
82         throw_from_string_out_of_range(func);
83     if (ptr == p)
84         throw_from_string_invalid_arg(func);
85     if (idx)
86         *idx = static_cast<size_t>(ptr - p);
87     return r;
88 }
89 
90 template<typename V, typename S>
91 inline V as_integer(const string& func, const S& s, size_t* idx, int base);
92 
93 // string
94 template<>
95 inline int as_integer(const string& func, const string& s, size_t* idx, int base) {
96     // Use long as no Standard string to integer exists.
97     long r = as_integer_helper<long>(func, s, idx, base, strtol);
98     if (r < numeric_limits<int>::min() || numeric_limits<int>::max() < r)
99         throw_from_string_out_of_range(func);
100     return static_cast<int>(r);
101 }
102 
103 template<>
104 inline long as_integer(const string& func, const string& s, size_t* idx, int base) {
105     return as_integer_helper<long>(func, s, idx, base, strtol);
106 }
107 
108 template<>
109 inline unsigned long as_integer(const string& func, const string& s, size_t* idx, int base) {
110     return as_integer_helper<unsigned long>(func, s, idx, base, strtoul);
111 }
112 
113 template<>
114 inline long long as_integer(const string& func, const string& s, size_t* idx, int base) {
115     return as_integer_helper<long long>(func, s, idx, base, strtoll);
116 }
117 
118 template<>
119 inline unsigned long long as_integer(const string& func, const string& s, size_t* idx, int base) {
120     return as_integer_helper<unsigned long long>(func, s, idx, base, strtoull);
121 }
122 
123 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
124 // wstring
125 template<>
126 inline int as_integer(const string& func, const wstring& s, size_t* idx, int base) {
127     // Use long as no Stantard string to integer exists.
128     long r = as_integer_helper<long>(func, s, idx, base, wcstol);
129     if (r < numeric_limits<int>::min() || numeric_limits<int>::max() < r)
130         throw_from_string_out_of_range(func);
131     return static_cast<int>(r);
132 }
133 
134 template<>
135 inline long as_integer(const string& func, const wstring& s, size_t* idx, int base) {
136     return as_integer_helper<long>(func, s, idx, base, wcstol);
137 }
138 
139 template<>
140 inline
141 unsigned long
142 as_integer(const string& func, const wstring& s, size_t* idx, int base)
143 {
144     return as_integer_helper<unsigned long>(func, s, idx, base, wcstoul);
145 }
146 
147 template<>
148 inline long long as_integer(const string& func, const wstring& s, size_t* idx, int base) {
149     return as_integer_helper<long long>(func, s, idx, base, wcstoll);
150 }
151 
152 template<>
153 inline unsigned long long as_integer(const string& func, const wstring& s, size_t* idx, int base) {
154     return as_integer_helper<unsigned long long>(func, s, idx, base, wcstoull);
155 }
156 #endif // _LIBCPP_HAS_NO_WIDE_CHARACTERS
157 
158 // as_float
159 
160 template<typename V, typename S, typename F>
161 inline V as_float_helper(const string& func, const S& str, size_t* idx, F f) {
162     typename S::value_type* ptr = nullptr;
163     const typename S::value_type* const p = str.c_str();
164     __libcpp_remove_reference_t<decltype(errno)> errno_save = errno;
165     errno = 0;
166     V r = f(p, &ptr);
167     swap(errno, errno_save);
168     if (errno_save == ERANGE)
169         throw_from_string_out_of_range(func);
170     if (ptr == p)
171         throw_from_string_invalid_arg(func);
172     if (idx)
173         *idx = static_cast<size_t>(ptr - p);
174     return r;
175 }
176 
177 template<typename V, typename S>
178 inline V as_float(const string& func, const S& s, size_t* idx = nullptr);
179 
180 template<>
181 inline float as_float(const string& func, const string& s, size_t* idx) {
182     return as_float_helper<float>(func, s, idx, strtof);
183 }
184 
185 template<>
186 inline double as_float(const string& func, const string& s, size_t* idx) {
187     return as_float_helper<double>(func, s, idx, strtod);
188 }
189 
190 template<>
191 inline long double as_float(const string& func, const string& s, size_t* idx) {
192     return as_float_helper<long double>(func, s, idx, strtold);
193 }
194 
195 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
196 template<>
197 inline float as_float(const string& func, const wstring& s, size_t* idx) {
198     return as_float_helper<float>(func, s, idx, wcstof);
199 }
200 
201 template<>
202 inline double as_float(const string& func, const wstring& s, size_t* idx) {
203     return as_float_helper<double>(func, s, idx, wcstod);
204 }
205 
206 template<>
207 inline long double as_float(const string& func, const wstring& s, size_t* idx) {
208     return as_float_helper<long double>(func, s, idx, wcstold);
209 }
210 #endif // _LIBCPP_HAS_NO_WIDE_CHARACTERS
211 
212 }  // unnamed namespace
213 
214 int stoi(const string& str, size_t* idx, int base) {
215     return as_integer<int>("stoi", str, idx, base);
216 }
217 
218 long stol(const string& str, size_t* idx, int base) {
219     return as_integer<long>("stol", str, idx, base);
220 }
221 
222 unsigned long stoul(const string& str, size_t* idx, int base) {
223     return as_integer<unsigned long>("stoul", str, idx, base);
224 }
225 
226 long long stoll(const string& str, size_t* idx, int base) {
227     return as_integer<long long>("stoll", str, idx, base);
228 }
229 
230 unsigned long long stoull(const string& str, size_t* idx, int base) {
231     return as_integer<unsigned long long>("stoull", str, idx, base);
232 }
233 
234 float stof(const string& str, size_t* idx) {
235     return as_float<float>("stof", str, idx);
236 }
237 
238 double stod(const string& str, size_t* idx) {
239     return as_float<double>("stod", str, idx);
240 }
241 
242 long double stold(const string& str, size_t* idx) {
243     return as_float<long double>("stold", str, idx);
244 }
245 
246 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
247 int stoi(const wstring& str, size_t* idx, int base) {
248     return as_integer<int>("stoi", str, idx, base);
249 }
250 
251 long stol(const wstring& str, size_t* idx, int base) {
252     return as_integer<long>("stol", str, idx, base);
253 }
254 
255 unsigned long stoul(const wstring& str, size_t* idx, int base) {
256     return as_integer<unsigned long>("stoul", str, idx, base);
257 }
258 
259 long long stoll(const wstring& str, size_t* idx, int base) {
260     return as_integer<long long>("stoll", str, idx, base);
261 }
262 
263 unsigned long long stoull(const wstring& str, size_t* idx, int base) {
264     return as_integer<unsigned long long>("stoull", str, idx, base);
265 }
266 
267 float stof(const wstring& str, size_t* idx) {
268     return as_float<float>("stof", str, idx);
269 }
270 
271 double stod(const wstring& str, size_t* idx) {
272     return as_float<double>("stod", str, idx);
273 }
274 
275 long double stold(const wstring& str, size_t* idx) {
276     return as_float<long double>("stold", str, idx);
277 }
278 #endif // !_LIBCPP_HAS_NO_WIDE_CHARACTERS
279 
280 // to_string
281 
282 namespace
283 {
284 
285 // as_string
286 
287 template<typename S, typename P, typename V >
288 inline S as_string(P sprintf_like, S s, const typename S::value_type* fmt, V a) {
289     typedef typename S::size_type size_type;
290     size_type available = s.size();
291     while (true) {
292         int status = sprintf_like(&s[0], available + 1, fmt, a);
293         if (status >= 0) {
294             size_type used = static_cast<size_type>(status);
295             if (used <= available) {
296                 s.resize(used);
297                 break;
298             }
299             available = used; // Assume this is advice of how much space we need.
300         }
301         else
302             available = available * 2 + 1;
303         s.resize(available);
304     }
305     return s;
306 }
307 
308 template <class S>
309 struct initial_string;
310 
311 template <>
312 struct initial_string<string> {
313     string operator()() const {
314         string s;
315         s.resize(s.capacity());
316         return s;
317     }
318 };
319 
320 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
321 template <>
322 struct initial_string<wstring> {
323     wstring operator()() const {
324         wstring s(20, wchar_t());
325         s.resize(s.capacity());
326         return s;
327     }
328 };
329 
330 typedef int (*wide_printf)(wchar_t* __restrict, size_t, const wchar_t*__restrict, ...);
331 
332 inline wide_printf get_swprintf() {
333 #ifndef _LIBCPP_MSVCRT
334     return swprintf;
335 #else
336     return static_cast<int (__cdecl*)(wchar_t* __restrict, size_t, const wchar_t*__restrict, ...)>(_snwprintf);
337 #endif
338 }
339 #endif // _LIBCPP_HAS_NO_WIDE_CHARACTERS
340 
341 template <typename S, typename V>
342 S i_to_string(V v) {
343 //  numeric_limits::digits10 returns value less on 1 than desired for unsigned numbers.
344 //  For example, for 1-byte unsigned value digits10 is 2 (999 can not be represented),
345 //  so we need +1 here.
346     constexpr size_t bufsize = numeric_limits<V>::digits10 + 2;  // +1 for minus, +1 for digits10
347     char buf[bufsize];
348     const auto res = to_chars(buf, buf + bufsize, v);
349     _LIBCPP_ASSERT_INTERNAL(res.ec == errc(), "bufsize must be large enough to accomodate the value");
350     return S(buf, res.ptr);
351 }
352 
353 }  // unnamed namespace
354 
355 string  to_string (int val)                { return i_to_string< string>(val); }
356 string  to_string (long val)               { return i_to_string< string>(val); }
357 string  to_string (long long val)          { return i_to_string< string>(val); }
358 string  to_string (unsigned val)           { return i_to_string< string>(val); }
359 string  to_string (unsigned long val)      { return i_to_string< string>(val); }
360 string  to_string (unsigned long long val) { return i_to_string< string>(val); }
361 
362 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
363 wstring to_wstring(int val)                { return i_to_string<wstring>(val); }
364 wstring to_wstring(long val)               { return i_to_string<wstring>(val); }
365 wstring to_wstring(long long val)          { return i_to_string<wstring>(val); }
366 wstring to_wstring(unsigned val)           { return i_to_string<wstring>(val); }
367 wstring to_wstring(unsigned long val)      { return i_to_string<wstring>(val); }
368 wstring to_wstring(unsigned long long val) { return i_to_string<wstring>(val); }
369 #endif
370 
371 string  to_string (float val)       { return as_string(snprintf,       initial_string< string>()(),   "%f", val); }
372 string  to_string (double val)      { return as_string(snprintf,       initial_string< string>()(),   "%f", val); }
373 string  to_string (long double val) { return as_string(snprintf,       initial_string< string>()(),  "%Lf", val); }
374 
375 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
376 wstring to_wstring(float val)       { return as_string(get_swprintf(), initial_string<wstring>()(),  L"%f", val); }
377 wstring to_wstring(double val)      { return as_string(get_swprintf(), initial_string<wstring>()(),  L"%f", val); }
378 wstring to_wstring(long double val) { return as_string(get_swprintf(), initial_string<wstring>()(), L"%Lf", val); }
379 #endif
380 
381 _LIBCPP_END_NAMESPACE_STD
382