src/cpp-common: add {fmt} 10.1.1
[babeltrace.git] / src / cpp-common / vendor / fmt / printf.h
1 // Formatting library for C++ - legacy printf implementation
2 //
3 // Copyright (c) 2012 - 2016, Victor Zverovich
4 // All rights reserved.
5 //
6 // For the license information refer to format.h.
7
8 #ifndef FMT_PRINTF_H_
9 #define FMT_PRINTF_H_
10
11 #include <algorithm> // std::max
12 #include <limits> // std::numeric_limits
13
14 #include "format.h"
15
16 FMT_BEGIN_NAMESPACE
17 FMT_BEGIN_EXPORT
18
19 template <typename T> struct printf_formatter { printf_formatter() = delete; };
20
21 template <typename Char> class basic_printf_context {
22 private:
23 detail::buffer_appender<Char> out_;
24 basic_format_args<basic_printf_context> args_;
25
26 public:
27 using char_type = Char;
28 using parse_context_type = basic_format_parse_context<Char>;
29 template <typename T> using formatter_type = printf_formatter<T>;
30
31 /**
32 \rst
33 Constructs a ``printf_context`` object. References to the arguments are
34 stored in the context object so make sure they have appropriate lifetimes.
35 \endrst
36 */
37 basic_printf_context(detail::buffer_appender<Char> out,
38 basic_format_args<basic_printf_context> args)
39 : out_(out), args_(args) {}
40
41 auto out() -> detail::buffer_appender<Char> { return out_; }
42 void advance_to(detail::buffer_appender<Char>) {}
43
44 auto locale() -> detail::locale_ref { return {}; }
45
46 auto arg(int id) const -> basic_format_arg<basic_printf_context> {
47 return args_.get(id);
48 }
49
50 FMT_CONSTEXPR void on_error(const char* message) {
51 detail::error_handler().on_error(message);
52 }
53 };
54
55 namespace detail {
56
57 // Checks if a value fits in int - used to avoid warnings about comparing
58 // signed and unsigned integers.
59 template <bool IsSigned> struct int_checker {
60 template <typename T> static auto fits_in_int(T value) -> bool {
61 unsigned max = max_value<int>();
62 return value <= max;
63 }
64 static auto fits_in_int(bool) -> bool { return true; }
65 };
66
67 template <> struct int_checker<true> {
68 template <typename T> static auto fits_in_int(T value) -> bool {
69 return value >= (std::numeric_limits<int>::min)() &&
70 value <= max_value<int>();
71 }
72 static auto fits_in_int(int) -> bool { return true; }
73 };
74
75 struct printf_precision_handler {
76 template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
77 auto operator()(T value) -> int {
78 if (!int_checker<std::numeric_limits<T>::is_signed>::fits_in_int(value))
79 throw_format_error("number is too big");
80 return (std::max)(static_cast<int>(value), 0);
81 }
82
83 template <typename T, FMT_ENABLE_IF(!std::is_integral<T>::value)>
84 auto operator()(T) -> int {
85 throw_format_error("precision is not integer");
86 return 0;
87 }
88 };
89
90 // An argument visitor that returns true iff arg is a zero integer.
91 struct is_zero_int {
92 template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
93 auto operator()(T value) -> bool {
94 return value == 0;
95 }
96
97 template <typename T, FMT_ENABLE_IF(!std::is_integral<T>::value)>
98 auto operator()(T) -> bool {
99 return false;
100 }
101 };
102
103 template <typename T> struct make_unsigned_or_bool : std::make_unsigned<T> {};
104
105 template <> struct make_unsigned_or_bool<bool> { using type = bool; };
106
107 template <typename T, typename Context> class arg_converter {
108 private:
109 using char_type = typename Context::char_type;
110
111 basic_format_arg<Context>& arg_;
112 char_type type_;
113
114 public:
115 arg_converter(basic_format_arg<Context>& arg, char_type type)
116 : arg_(arg), type_(type) {}
117
118 void operator()(bool value) {
119 if (type_ != 's') operator()<bool>(value);
120 }
121
122 template <typename U, FMT_ENABLE_IF(std::is_integral<U>::value)>
123 void operator()(U value) {
124 bool is_signed = type_ == 'd' || type_ == 'i';
125 using target_type = conditional_t<std::is_same<T, void>::value, U, T>;
126 if (const_check(sizeof(target_type) <= sizeof(int))) {
127 // Extra casts are used to silence warnings.
128 if (is_signed) {
129 auto n = static_cast<int>(static_cast<target_type>(value));
130 arg_ = detail::make_arg<Context>(n);
131 } else {
132 using unsigned_type = typename make_unsigned_or_bool<target_type>::type;
133 auto n = static_cast<unsigned>(static_cast<unsigned_type>(value));
134 arg_ = detail::make_arg<Context>(n);
135 }
136 } else {
137 if (is_signed) {
138 // glibc's printf doesn't sign extend arguments of smaller types:
139 // std::printf("%lld", -42); // prints "4294967254"
140 // but we don't have to do the same because it's a UB.
141 auto n = static_cast<long long>(value);
142 arg_ = detail::make_arg<Context>(n);
143 } else {
144 auto n = static_cast<typename make_unsigned_or_bool<U>::type>(value);
145 arg_ = detail::make_arg<Context>(n);
146 }
147 }
148 }
149
150 template <typename U, FMT_ENABLE_IF(!std::is_integral<U>::value)>
151 void operator()(U) {} // No conversion needed for non-integral types.
152 };
153
154 // Converts an integer argument to T for printf, if T is an integral type.
155 // If T is void, the argument is converted to corresponding signed or unsigned
156 // type depending on the type specifier: 'd' and 'i' - signed, other -
157 // unsigned).
158 template <typename T, typename Context, typename Char>
159 void convert_arg(basic_format_arg<Context>& arg, Char type) {
160 visit_format_arg(arg_converter<T, Context>(arg, type), arg);
161 }
162
163 // Converts an integer argument to char for printf.
164 template <typename Context> class char_converter {
165 private:
166 basic_format_arg<Context>& arg_;
167
168 public:
169 explicit char_converter(basic_format_arg<Context>& arg) : arg_(arg) {}
170
171 template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
172 void operator()(T value) {
173 auto c = static_cast<typename Context::char_type>(value);
174 arg_ = detail::make_arg<Context>(c);
175 }
176
177 template <typename T, FMT_ENABLE_IF(!std::is_integral<T>::value)>
178 void operator()(T) {} // No conversion needed for non-integral types.
179 };
180
181 // An argument visitor that return a pointer to a C string if argument is a
182 // string or null otherwise.
183 template <typename Char> struct get_cstring {
184 template <typename T> auto operator()(T) -> const Char* { return nullptr; }
185 auto operator()(const Char* s) -> const Char* { return s; }
186 };
187
188 // Checks if an argument is a valid printf width specifier and sets
189 // left alignment if it is negative.
190 template <typename Char> class printf_width_handler {
191 private:
192 format_specs<Char>& specs_;
193
194 public:
195 explicit printf_width_handler(format_specs<Char>& specs) : specs_(specs) {}
196
197 template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
198 auto operator()(T value) -> unsigned {
199 auto width = static_cast<uint32_or_64_or_128_t<T>>(value);
200 if (detail::is_negative(value)) {
201 specs_.align = align::left;
202 width = 0 - width;
203 }
204 unsigned int_max = max_value<int>();
205 if (width > int_max) throw_format_error("number is too big");
206 return static_cast<unsigned>(width);
207 }
208
209 template <typename T, FMT_ENABLE_IF(!std::is_integral<T>::value)>
210 auto operator()(T) -> unsigned {
211 throw_format_error("width is not integer");
212 return 0;
213 }
214 };
215
216 // Workaround for a bug with the XL compiler when initializing
217 // printf_arg_formatter's base class.
218 template <typename Char>
219 auto make_arg_formatter(buffer_appender<Char> iter, format_specs<Char>& s)
220 -> arg_formatter<Char> {
221 return {iter, s, locale_ref()};
222 }
223
224 // The ``printf`` argument formatter.
225 template <typename Char>
226 class printf_arg_formatter : public arg_formatter<Char> {
227 private:
228 using base = arg_formatter<Char>;
229 using context_type = basic_printf_context<Char>;
230
231 context_type& context_;
232
233 void write_null_pointer(bool is_string = false) {
234 auto s = this->specs;
235 s.type = presentation_type::none;
236 write_bytes(this->out, is_string ? "(null)" : "(nil)", s);
237 }
238
239 public:
240 printf_arg_formatter(buffer_appender<Char> iter, format_specs<Char>& s,
241 context_type& ctx)
242 : base(make_arg_formatter(iter, s)), context_(ctx) {}
243
244 void operator()(monostate value) { base::operator()(value); }
245
246 template <typename T, FMT_ENABLE_IF(detail::is_integral<T>::value)>
247 void operator()(T value) {
248 // MSVC2013 fails to compile separate overloads for bool and Char so use
249 // std::is_same instead.
250 if (!std::is_same<T, Char>::value) {
251 base::operator()(value);
252 return;
253 }
254 format_specs<Char> fmt_specs = this->specs;
255 if (fmt_specs.type != presentation_type::none &&
256 fmt_specs.type != presentation_type::chr) {
257 return (*this)(static_cast<int>(value));
258 }
259 fmt_specs.sign = sign::none;
260 fmt_specs.alt = false;
261 fmt_specs.fill[0] = ' '; // Ignore '0' flag for char types.
262 // align::numeric needs to be overwritten here since the '0' flag is
263 // ignored for non-numeric types
264 if (fmt_specs.align == align::none || fmt_specs.align == align::numeric)
265 fmt_specs.align = align::right;
266 write<Char>(this->out, static_cast<Char>(value), fmt_specs);
267 }
268
269 template <typename T, FMT_ENABLE_IF(std::is_floating_point<T>::value)>
270 void operator()(T value) {
271 base::operator()(value);
272 }
273
274 /** Formats a null-terminated C string. */
275 void operator()(const char* value) {
276 if (value)
277 base::operator()(value);
278 else
279 write_null_pointer(this->specs.type != presentation_type::pointer);
280 }
281
282 /** Formats a null-terminated wide C string. */
283 void operator()(const wchar_t* value) {
284 if (value)
285 base::operator()(value);
286 else
287 write_null_pointer(this->specs.type != presentation_type::pointer);
288 }
289
290 void operator()(basic_string_view<Char> value) { base::operator()(value); }
291
292 /** Formats a pointer. */
293 void operator()(const void* value) {
294 if (value)
295 base::operator()(value);
296 else
297 write_null_pointer();
298 }
299
300 /** Formats an argument of a custom (user-defined) type. */
301 void operator()(typename basic_format_arg<context_type>::handle handle) {
302 auto parse_ctx = basic_format_parse_context<Char>({});
303 handle.format(parse_ctx, context_);
304 }
305 };
306
307 template <typename Char>
308 void parse_flags(format_specs<Char>& specs, const Char*& it, const Char* end) {
309 for (; it != end; ++it) {
310 switch (*it) {
311 case '-':
312 specs.align = align::left;
313 break;
314 case '+':
315 specs.sign = sign::plus;
316 break;
317 case '0':
318 specs.fill[0] = '0';
319 break;
320 case ' ':
321 if (specs.sign != sign::plus) specs.sign = sign::space;
322 break;
323 case '#':
324 specs.alt = true;
325 break;
326 default:
327 return;
328 }
329 }
330 }
331
332 template <typename Char, typename GetArg>
333 auto parse_header(const Char*& it, const Char* end, format_specs<Char>& specs,
334 GetArg get_arg) -> int {
335 int arg_index = -1;
336 Char c = *it;
337 if (c >= '0' && c <= '9') {
338 // Parse an argument index (if followed by '$') or a width possibly
339 // preceded with '0' flag(s).
340 int value = parse_nonnegative_int(it, end, -1);
341 if (it != end && *it == '$') { // value is an argument index
342 ++it;
343 arg_index = value != -1 ? value : max_value<int>();
344 } else {
345 if (c == '0') specs.fill[0] = '0';
346 if (value != 0) {
347 // Nonzero value means that we parsed width and don't need to
348 // parse it or flags again, so return now.
349 if (value == -1) throw_format_error("number is too big");
350 specs.width = value;
351 return arg_index;
352 }
353 }
354 }
355 parse_flags(specs, it, end);
356 // Parse width.
357 if (it != end) {
358 if (*it >= '0' && *it <= '9') {
359 specs.width = parse_nonnegative_int(it, end, -1);
360 if (specs.width == -1) throw_format_error("number is too big");
361 } else if (*it == '*') {
362 ++it;
363 specs.width = static_cast<int>(visit_format_arg(
364 detail::printf_width_handler<Char>(specs), get_arg(-1)));
365 }
366 }
367 return arg_index;
368 }
369
370 inline auto parse_printf_presentation_type(char c, type t)
371 -> presentation_type {
372 using pt = presentation_type;
373 constexpr auto integral_set = sint_set | uint_set | bool_set | char_set;
374 switch (c) {
375 case 'd':
376 return in(t, integral_set) ? pt::dec : pt::none;
377 case 'o':
378 return in(t, integral_set) ? pt::oct : pt::none;
379 case 'x':
380 return in(t, integral_set) ? pt::hex_lower : pt::none;
381 case 'X':
382 return in(t, integral_set) ? pt::hex_upper : pt::none;
383 case 'a':
384 return in(t, float_set) ? pt::hexfloat_lower : pt::none;
385 case 'A':
386 return in(t, float_set) ? pt::hexfloat_upper : pt::none;
387 case 'e':
388 return in(t, float_set) ? pt::exp_lower : pt::none;
389 case 'E':
390 return in(t, float_set) ? pt::exp_upper : pt::none;
391 case 'f':
392 return in(t, float_set) ? pt::fixed_lower : pt::none;
393 case 'F':
394 return in(t, float_set) ? pt::fixed_upper : pt::none;
395 case 'g':
396 return in(t, float_set) ? pt::general_lower : pt::none;
397 case 'G':
398 return in(t, float_set) ? pt::general_upper : pt::none;
399 case 'c':
400 return in(t, integral_set) ? pt::chr : pt::none;
401 case 's':
402 return in(t, string_set | cstring_set) ? pt::string : pt::none;
403 case 'p':
404 return in(t, pointer_set | cstring_set) ? pt::pointer : pt::none;
405 default:
406 return pt::none;
407 }
408 }
409
410 template <typename Char, typename Context>
411 void vprintf(buffer<Char>& buf, basic_string_view<Char> format,
412 basic_format_args<Context> args) {
413 using iterator = buffer_appender<Char>;
414 auto out = iterator(buf);
415 auto context = basic_printf_context<Char>(out, args);
416 auto parse_ctx = basic_format_parse_context<Char>(format);
417
418 // Returns the argument with specified index or, if arg_index is -1, the next
419 // argument.
420 auto get_arg = [&](int arg_index) {
421 if (arg_index < 0)
422 arg_index = parse_ctx.next_arg_id();
423 else
424 parse_ctx.check_arg_id(--arg_index);
425 return detail::get_arg(context, arg_index);
426 };
427
428 const Char* start = parse_ctx.begin();
429 const Char* end = parse_ctx.end();
430 auto it = start;
431 while (it != end) {
432 if (!find<false, Char>(it, end, '%', it)) {
433 it = end; // find leaves it == nullptr if it doesn't find '%'.
434 break;
435 }
436 Char c = *it++;
437 if (it != end && *it == c) {
438 write(out, basic_string_view<Char>(start, to_unsigned(it - start)));
439 start = ++it;
440 continue;
441 }
442 write(out, basic_string_view<Char>(start, to_unsigned(it - 1 - start)));
443
444 auto specs = format_specs<Char>();
445 specs.align = align::right;
446
447 // Parse argument index, flags and width.
448 int arg_index = parse_header(it, end, specs, get_arg);
449 if (arg_index == 0) throw_format_error("argument not found");
450
451 // Parse precision.
452 if (it != end && *it == '.') {
453 ++it;
454 c = it != end ? *it : 0;
455 if ('0' <= c && c <= '9') {
456 specs.precision = parse_nonnegative_int(it, end, 0);
457 } else if (c == '*') {
458 ++it;
459 specs.precision = static_cast<int>(
460 visit_format_arg(printf_precision_handler(), get_arg(-1)));
461 } else {
462 specs.precision = 0;
463 }
464 }
465
466 auto arg = get_arg(arg_index);
467 // For d, i, o, u, x, and X conversion specifiers, if a precision is
468 // specified, the '0' flag is ignored
469 if (specs.precision >= 0 && arg.is_integral()) {
470 // Ignore '0' for non-numeric types or if '-' present.
471 specs.fill[0] = ' ';
472 }
473 if (specs.precision >= 0 && arg.type() == type::cstring_type) {
474 auto str = visit_format_arg(get_cstring<Char>(), arg);
475 auto str_end = str + specs.precision;
476 auto nul = std::find(str, str_end, Char());
477 auto sv = basic_string_view<Char>(
478 str, to_unsigned(nul != str_end ? nul - str : specs.precision));
479 arg = make_arg<basic_printf_context<Char>>(sv);
480 }
481 if (specs.alt && visit_format_arg(is_zero_int(), arg)) specs.alt = false;
482 if (specs.fill[0] == '0') {
483 if (arg.is_arithmetic() && specs.align != align::left)
484 specs.align = align::numeric;
485 else
486 specs.fill[0] = ' '; // Ignore '0' flag for non-numeric types or if '-'
487 // flag is also present.
488 }
489
490 // Parse length and convert the argument to the required type.
491 c = it != end ? *it++ : 0;
492 Char t = it != end ? *it : 0;
493 switch (c) {
494 case 'h':
495 if (t == 'h') {
496 ++it;
497 t = it != end ? *it : 0;
498 convert_arg<signed char>(arg, t);
499 } else {
500 convert_arg<short>(arg, t);
501 }
502 break;
503 case 'l':
504 if (t == 'l') {
505 ++it;
506 t = it != end ? *it : 0;
507 convert_arg<long long>(arg, t);
508 } else {
509 convert_arg<long>(arg, t);
510 }
511 break;
512 case 'j':
513 convert_arg<intmax_t>(arg, t);
514 break;
515 case 'z':
516 convert_arg<size_t>(arg, t);
517 break;
518 case 't':
519 convert_arg<std::ptrdiff_t>(arg, t);
520 break;
521 case 'L':
522 // printf produces garbage when 'L' is omitted for long double, no
523 // need to do the same.
524 break;
525 default:
526 --it;
527 convert_arg<void>(arg, c);
528 }
529
530 // Parse type.
531 if (it == end) throw_format_error("invalid format string");
532 char type = static_cast<char>(*it++);
533 if (arg.is_integral()) {
534 // Normalize type.
535 switch (type) {
536 case 'i':
537 case 'u':
538 type = 'd';
539 break;
540 case 'c':
541 visit_format_arg(char_converter<basic_printf_context<Char>>(arg), arg);
542 break;
543 }
544 }
545 specs.type = parse_printf_presentation_type(type, arg.type());
546 if (specs.type == presentation_type::none)
547 throw_format_error("invalid format specifier");
548
549 start = it;
550
551 // Format argument.
552 visit_format_arg(printf_arg_formatter<Char>(out, specs, context), arg);
553 }
554 write(out, basic_string_view<Char>(start, to_unsigned(it - start)));
555 }
556 } // namespace detail
557
558 using printf_context = basic_printf_context<char>;
559 using wprintf_context = basic_printf_context<wchar_t>;
560
561 using printf_args = basic_format_args<printf_context>;
562 using wprintf_args = basic_format_args<wprintf_context>;
563
564 /**
565 \rst
566 Constructs an `~fmt::format_arg_store` object that contains references to
567 arguments and can be implicitly converted to `~fmt::printf_args`.
568 \endrst
569 */
570 template <typename... T>
571 inline auto make_printf_args(const T&... args)
572 -> format_arg_store<printf_context, T...> {
573 return {args...};
574 }
575
576 // DEPRECATED!
577 template <typename... T>
578 inline auto make_wprintf_args(const T&... args)
579 -> format_arg_store<wprintf_context, T...> {
580 return {args...};
581 }
582
583 template <typename Char>
584 inline auto vsprintf(
585 basic_string_view<Char> fmt,
586 basic_format_args<basic_printf_context<type_identity_t<Char>>> args)
587 -> std::basic_string<Char> {
588 auto buf = basic_memory_buffer<Char>();
589 detail::vprintf(buf, fmt, args);
590 return to_string(buf);
591 }
592
593 /**
594 \rst
595 Formats arguments and returns the result as a string.
596
597 **Example**::
598
599 std::string message = fmt::sprintf("The answer is %d", 42);
600 \endrst
601 */
602 template <typename S, typename... T,
603 typename Char = enable_if_t<detail::is_string<S>::value, char_t<S>>>
604 inline auto sprintf(const S& fmt, const T&... args) -> std::basic_string<Char> {
605 return vsprintf(detail::to_string_view(fmt),
606 fmt::make_format_args<basic_printf_context<Char>>(args...));
607 }
608
609 template <typename Char>
610 inline auto vfprintf(
611 std::FILE* f, basic_string_view<Char> fmt,
612 basic_format_args<basic_printf_context<type_identity_t<Char>>> args)
613 -> int {
614 auto buf = basic_memory_buffer<Char>();
615 detail::vprintf(buf, fmt, args);
616 size_t size = buf.size();
617 return std::fwrite(buf.data(), sizeof(Char), size, f) < size
618 ? -1
619 : static_cast<int>(size);
620 }
621
622 /**
623 \rst
624 Prints formatted data to the file *f*.
625
626 **Example**::
627
628 fmt::fprintf(stderr, "Don't %s!", "panic");
629 \endrst
630 */
631 template <typename S, typename... T, typename Char = char_t<S>>
632 inline auto fprintf(std::FILE* f, const S& fmt, const T&... args) -> int {
633 return vfprintf(f, detail::to_string_view(fmt),
634 fmt::make_format_args<basic_printf_context<Char>>(args...));
635 }
636
637 template <typename Char>
638 FMT_DEPRECATED inline auto vprintf(
639 basic_string_view<Char> fmt,
640 basic_format_args<basic_printf_context<type_identity_t<Char>>> args)
641 -> int {
642 return vfprintf(stdout, fmt, args);
643 }
644
645 /**
646 \rst
647 Prints formatted data to ``stdout``.
648
649 **Example**::
650
651 fmt::printf("Elapsed time: %.2f seconds", 1.23);
652 \endrst
653 */
654 template <typename... T>
655 inline auto printf(string_view fmt, const T&... args) -> int {
656 return vfprintf(stdout, fmt, make_printf_args(args...));
657 }
658 template <typename... T>
659 FMT_DEPRECATED inline auto printf(basic_string_view<wchar_t> fmt,
660 const T&... args) -> int {
661 return vfprintf(stdout, fmt, make_wprintf_args(args...));
662 }
663
664 FMT_END_EXPORT
665 FMT_END_NAMESPACE
666
667 #endif // FMT_PRINTF_H_
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