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Diffstat (limited to 'third_party/printf/printf.h')
| -rw-r--r-- | third_party/printf/printf.h | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/third_party/printf/printf.h b/third_party/printf/printf.h new file mode 100644 index 0000000..fb43fe2 --- /dev/null +++ b/third_party/printf/printf.h @@ -0,0 +1,215 @@ +/** + * @author (c) Eyal Rozenberg <eyalroz1@gmx.com> + * 2021-2022, Haifa, Palestine/Israel + * @author (c) Marco Paland (info@paland.com) + * 2014-2019, PALANDesign Hannover, Germany + * + * @note Others have made smaller contributions to this file: see the + * contributors page at https://github.com/eyalroz/printf/graphs/contributors + * or ask one of the authors. + * + * @brief Small stand-alone implementation of the printf family of functions + * (`(v)printf`, `(v)s(n)printf` etc., geared towards use on embedded systems with + * a very limited resources. + * + * @note the implementations are thread-safe; re-entrant; use no functions from + * the standard library; and do not dynamically allocate any memory. + * + * @license The MIT License (MIT) + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +#ifndef PRINTF_H_ +#define PRINTF_H_ + +#ifdef __cplusplus +# include <cstdarg> +# include <cstddef> +extern "C" { +#else +# include <stdarg.h> +# include <stddef.h> +#endif + +#ifdef __GNUC__ +# if ((__GNUC__ == 4 && __GNUC_MINOR__>= 4) || __GNUC__ > 4) +# define ATTR_PRINTF(one_based_format_index, first_arg) \ +__attribute__((format(gnu_printf, (one_based_format_index), (first_arg)))) +# else +# define ATTR_PRINTF(one_based_format_index, first_arg) \ +__attribute__((format(printf, (one_based_format_index), (first_arg)))) +# endif +# define ATTR_VPRINTF(one_based_format_index) ATTR_PRINTF((one_based_format_index), 0) +#else +# define ATTR_PRINTF(one_based_format_index, first_arg) +# define ATTR_VPRINTF(one_based_format_index) +#endif + +#ifndef PRINTF_ALIAS_STANDARD_FUNCTION_NAMES +#define PRINTF_ALIAS_STANDARD_FUNCTION_NAMES 0 +#endif + +#if PRINTF_ALIAS_STANDARD_FUNCTION_NAMES_HARD +# define printf_ printf +# define sprintf_ sprintf +# define vsprintf_ vsprintf +# define snprintf_ snprintf +# define vsnprintf_ vsnprintf +# define vprintf_ vprintf +#endif + +// If you want to include this implementation file directly rather than +// link against, this will let you control the functions' visibility, +// e.g. make them static so as not to clash with other objects also +// using them. +#ifndef PRINTF_VISIBILITY +#define PRINTF_VISIBILITY +#endif + +/** + * Prints/send a single character to some opaque output entity + * + * @note This function is not implemented by the library, only declared; you must provide an + * implementation if you wish to use the @ref printf / @ref vprintf function (and possibly + * for linking against the library, if your toolchain does not support discarding unused functions) + * + * @note The output could be as simple as a wrapper for the `write()` system call on a Unix-like + * system, or even libc's @ref putchar , for replicating actual functionality of libc's @ref printf + * function; but on an embedded system it may involve interaction with a special output device, + * like a UART, etc. + * + * @note in libc's @ref putchar, the parameter type is an int; this was intended to support the + * representation of either a proper character or EOF in a variable - but this is really not + * meaningful to pass into @ref putchar and is discouraged today. See further discussion in: + * @link https://stackoverflow.com/q/17452847/1593077 + * + * @param c the single character to print + */ +PRINTF_VISIBILITY +void putchar_(char c); + + +/** + * An implementation of the C standard's printf/vprintf + * + * @note you must implement a @ref putchar_ function for using this function - it invokes @ref putchar_ + * rather than directly performing any I/O (which insulates it from any dependence on the operating system + * and external libraries). + * + * @param format A string specifying the format of the output, with %-marked specifiers of how to interpret + * additional arguments. + * @param arg Additional arguments to the function, one for each %-specifier in @p format string + * @return The number of characters written into @p s, not counting the terminating null character + */ + ///@{ +PRINTF_VISIBILITY +int printf_(const char* format, ...) ATTR_PRINTF(1, 2); +PRINTF_VISIBILITY +int vprintf_(const char* format, va_list arg) ATTR_VPRINTF(1); +///@} + + +/** + * An implementation of the C standard's sprintf/vsprintf + * + * @note For security considerations (the potential for exceeding the buffer bounds), please consider using + * the size-constrained variant, @ref snprintf / @ref vsnprintf , instead. + * + * @param s An array in which to store the formatted string. It must be large enough to fit the formatted + * output! + * @param format A string specifying the format of the output, with %-marked specifiers of how to interpret + * additional arguments. + * @param arg Additional arguments to the function, one for each specifier in @p format + * @return The number of characters written into @p s, not counting the terminating null character + */ +///@{ +PRINTF_VISIBILITY +int sprintf_(char* s, const char* format, ...) ATTR_PRINTF(2, 3); +PRINTF_VISIBILITY +int vsprintf_(char* s, const char* format, va_list arg) ATTR_VPRINTF(2); +///@} + + +/** + * An implementation of the C standard's snprintf/vsnprintf + * + * @param s An array in which to store the formatted string. It must be large enough to fit either the + * entire formatted output, or at least @p n characters. Alternatively, it can be NULL, in which case + * nothing will be printed, and only the number of characters which _could_ have been printed is + * tallied and returned. + * @param n The maximum number of characters to write to the array, including a terminating null character + * @param format A string specifying the format of the output, with %-marked specifiers of how to interpret + * additional arguments. + * @param arg Additional arguments to the function, one for each specifier in @p format + * @return The number of characters that COULD have been written into @p s, not counting the terminating + * null character. A value equal or larger than @p n indicates truncation. Only when the returned value + * is non-negative and less than @p n, the null-terminated string has been fully and successfully printed. + */ +///@{ +PRINTF_VISIBILITY +int snprintf_(char* s, size_t count, const char* format, ...) ATTR_PRINTF(3, 4); +PRINTF_VISIBILITY +int vsnprintf_(char* s, size_t count, const char* format, va_list arg) ATTR_VPRINTF(3); +///@} + + + +/** + * printf/vprintf with user-specified output function + * + * An alternative to @ref printf_, in which the output function is specified dynamically + * (rather than @ref putchar_ being used) + * + * @param out An output function which takes one character and a type-erased additional parameters + * @param extra_arg The type-erased argument to pass to the output function @p out with each call + * @param format A string specifying the format of the output, with %-marked specifiers of how to interpret + * additional arguments. + * @param arg Additional arguments to the function, one for each specifier in @p format + * @return The number of characters for which the output f unction was invoked, not counting the terminating null character + * + */ +PRINTF_VISIBILITY +int fctprintf(void (*out)(char c, void* extra_arg), void* extra_arg, const char* format, ...) ATTR_PRINTF(3, 4); +PRINTF_VISIBILITY +int vfctprintf(void (*out)(char c, void* extra_arg), void* extra_arg, const char* format, va_list arg) ATTR_VPRINTF(3); + +#ifdef __cplusplus +} // extern "C" +#endif + +#if PRINTF_ALIAS_STANDARD_FUNCTION_NAMES_HARD +# undef printf_ +# undef sprintf_ +# undef vsprintf_ +# undef snprintf_ +# undef vsnprintf_ +# undef vprintf_ +#else +#if PRINTF_ALIAS_STANDARD_FUNCTION_NAMES_SOFT +# define printf printf_ +# define sprintf sprintf_ +# define vsprintf vsprintf_ +# define snprintf snprintf_ +# define vsnprintf vsnprintf_ +# define vprintf vprintf_ +#endif +#endif + +#endif // PRINTF_H_ |