From 97bfa178d1c5209b81e9e7b2590df4cdb44d3848 Mon Sep 17 00:00:00 2001 From: kamkow1 Date: Sat, 6 Sep 2025 12:14:54 +0200 Subject: [PATCH] Printf in userspace --- kernel/printf/printf.c | 1486 +-------------------------------- kernel/printf/printf.h | 237 +----- kernel/printf/printf_config.h | 3 +- share/printf/printf.c | 1485 ++++++++++++++++++++++++++++++++ share/printf/printf.h | 236 ++++++ share/printf/printf_config.h | 2 + ulib/Makefile | 4 +- ulib/printf/printf.c | 1 + ulib/printf/printf.h | 1 + ulib/printf/printf_config.h | 1 + ulib/putchar.c | 9 + ulib/uprintf.h | 13 + user/init/main.c | 6 +- 13 files changed, 1756 insertions(+), 1728 deletions(-) mode change 100644 => 120000 kernel/printf/printf.c mode change 100644 => 120000 kernel/printf/printf.h mode change 100644 => 120000 kernel/printf/printf_config.h create mode 100644 share/printf/printf.c create mode 100644 share/printf/printf.h create mode 100644 share/printf/printf_config.h create mode 120000 ulib/printf/printf.c create mode 120000 ulib/printf/printf.h create mode 120000 ulib/printf/printf_config.h create mode 100644 ulib/putchar.c create mode 100644 ulib/uprintf.h diff --git a/kernel/printf/printf.c b/kernel/printf/printf.c deleted file mode 100644 index e47bac6..0000000 --- a/kernel/printf/printf.c +++ /dev/null @@ -1,1485 +0,0 @@ -/** - * @author (c) Eyal Rozenberg - * 2021-2023, 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. The original code for exponential specifiers was - * contributed by Martijn Jasperse . - * - * @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 - * 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. - */ - -// Define this globally (e.g. gcc -DPRINTF_INCLUDE_CONFIG_H=1 ...) to include the -// printf_config.h header file -#if PRINTF_INCLUDE_CONFIG_H -#include "printf_config.h" -#endif - -#include - -#ifdef __cplusplus -#include -#include -#else -#include -#include -#include -#endif // __cplusplus - -#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 - - -// 'ntoa' conversion buffer size, this must be big enough to hold one converted -// numeric number including padded zeros (dynamically created on stack) -#ifndef PRINTF_INTEGER_BUFFER_SIZE -#define PRINTF_INTEGER_BUFFER_SIZE 32 -#endif - -// size of the fixed (on-stack) buffer for printing individual decimal numbers. -// this must be big enough to hold one converted floating-point value including -// padded zeros. -#ifndef PRINTF_DECIMAL_BUFFER_SIZE -#define PRINTF_DECIMAL_BUFFER_SIZE 32 -#endif - -// Support for the decimal notation floating point conversion specifiers (%f, %F) -#ifndef PRINTF_SUPPORT_DECIMAL_SPECIFIERS -#define PRINTF_SUPPORT_DECIMAL_SPECIFIERS 1 -#endif - -// Support for the exponential notation floating point conversion specifiers (%e, %g, %E, %G) -#ifndef PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS -#define PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS 1 -#endif - -// Support for the length write-back specifier (%n) -#ifndef PRINTF_SUPPORT_WRITEBACK_SPECIFIER -#define PRINTF_SUPPORT_WRITEBACK_SPECIFIER 1 -#endif - -// Default precision for the floating point conversion specifiers (the C standard sets this at 6) -#ifndef PRINTF_DEFAULT_FLOAT_PRECISION -#define PRINTF_DEFAULT_FLOAT_PRECISION 6 -#endif - -// Default choice of type to use for internal floating-point computations -#ifndef PRINTF_USE_DOUBLE_INTERNALLY -#define PRINTF_USE_DOUBLE_INTERNALLY 1 -#endif - -// According to the C languages standard, printf() and related functions must be able to print any -// integral number in floating-point notation, regardless of length, when using the %f specifier - -// possibly hundreds of characters, potentially overflowing your buffers. In this implementation, -// all values beyond this threshold are switched to exponential notation. -#ifndef PRINTF_MAX_INTEGRAL_DIGITS_FOR_DECIMAL -#define PRINTF_MAX_INTEGRAL_DIGITS_FOR_DECIMAL 9 -#endif - -// Support for the long long integral types (with the ll, z and t length modifiers for specifiers -// %d,%i,%o,%x,%X,%u, and with the %p specifier). -#ifndef PRINTF_SUPPORT_LONG_LONG -#define PRINTF_SUPPORT_LONG_LONG 1 -#endif - -// The number of terms in a Taylor series expansion of log_10(x) to -// use for approximation - including the power-zero term (i.e. the -// value at the point of expansion). -#ifndef PRINTF_LOG10_TAYLOR_TERMS -#define PRINTF_LOG10_TAYLOR_TERMS 4 -#endif - -#if PRINTF_LOG10_TAYLOR_TERMS <= 1 -#error "At least one non-constant Taylor expansion is necessary for the log10() calculation" -#endif - -// Be extra-safe, and don't assume format specifiers are completed correctly -// before the format string end. -#ifndef PRINTF_CHECK_FOR_NUL_IN_FORMAT_SPECIFIER -#define PRINTF_CHECK_FOR_NUL_IN_FORMAT_SPECIFIER 1 -#endif - -#define PRINTF_PREFER_DECIMAL false -#define PRINTF_PREFER_EXPONENTIAL true - -/////////////////////////////////////////////////////////////////////////////// - -// The following will convert the number-of-digits into an exponential-notation literal -#define PRINTF_CONCATENATE(s1, s2) s1##s2 -#define PRINTF_EXPAND_THEN_CONCATENATE(s1, s2) PRINTF_CONCATENATE(s1, s2) -#define PRINTF_FLOAT_NOTATION_THRESHOLD ((floating_point_t) PRINTF_EXPAND_THEN_CONCATENATE(1e,PRINTF_MAX_INTEGRAL_DIGITS_FOR_DECIMAL)) - -// internal flag definitions -#define FLAGS_ZEROPAD (1U << 0U) -#define FLAGS_LEFT (1U << 1U) -#define FLAGS_PLUS (1U << 2U) -#define FLAGS_SPACE (1U << 3U) -#define FLAGS_HASH (1U << 4U) -#define FLAGS_UPPERCASE (1U << 5U) -#define FLAGS_CHAR (1U << 6U) -#define FLAGS_SHORT (1U << 7U) -#define FLAGS_INT (1U << 8U) - // Only used with PRINTF_SUPPORT_MSVC_STYLE_INTEGER_SPECIFIERS -#define FLAGS_LONG (1U << 9U) -#define FLAGS_LONG_LONG (1U << 10U) -#define FLAGS_PRECISION (1U << 11U) -#define FLAGS_ADAPT_EXP (1U << 12U) -#define FLAGS_POINTER (1U << 13U) - // Note: Similar, but not identical, effect as FLAGS_HASH -#define FLAGS_SIGNED (1U << 14U) -#define FLAGS_LONG_DOUBLE (1U << 15U) - // Only used with PRINTF_SUPPORT_MSVC_STYLE_INTEGER_SPECIFIERS - -#ifdef PRINTF_SUPPORT_MSVC_STYLE_INTEGER_SPECIFIERS - -#define FLAGS_INT8 FLAGS_CHAR - - -#if (SHRT_MAX == 32767LL) -#define FLAGS_INT16 FLAGS_SHORT -#elif (INT_MAX == 32767LL) -#define FLAGS_INT16 FLAGS_INT -#elif (LONG_MAX == 32767LL) -#define FLAGS_INT16 FLAGS_LONG -#elif (LLONG_MAX == 32767LL) -#define FLAGS_INT16 FLAGS_LONG_LONG -#else -#error "No basic integer type has a size of 16 bits exactly" -#endif - -#if (SHRT_MAX == 2147483647LL) -#define FLAGS_INT32 FLAGS_SHORT -#elif (INT_MAX == 2147483647LL) -#define FLAGS_INT32 FLAGS_INT -#elif (LONG_MAX == 2147483647LL) -#define FLAGS_INT32 FLAGS_LONG -#elif (LLONG_MAX == 2147483647LL) -#define FLAGS_INT32 FLAGS_LONG_LONG -#else -#error "No basic integer type has a size of 32 bits exactly" -#endif - -#if (SHRT_MAX == 9223372036854775807LL) -#define FLAGS_INT64 FLAGS_SHORT -#elif (INT_MAX == 9223372036854775807LL) -#define FLAGS_INT64 FLAGS_INT -#elif (LONG_MAX == 9223372036854775807LL) -#define FLAGS_INT64 FLAGS_LONG -#elif (LLONG_MAX == 9223372036854775807LL) -#define FLAGS_INT64 FLAGS_LONG_LONG -#else -#error "No basic integer type has a size of 64 bits exactly" -#endif - -#endif // PRINTF_SUPPORT_MSVC_STYLE_INTEGER_SPECIFIERS - - -typedef unsigned int printf_flags_t; - -#define BASE_BINARY 2 -#define BASE_OCTAL 8 -#define BASE_DECIMAL 10 -#define BASE_HEX 16 - -typedef uint8_t numeric_base_t; - -#if PRINTF_SUPPORT_LONG_LONG -typedef unsigned long long printf_unsigned_value_t; -typedef long long printf_signed_value_t; -#else -typedef unsigned long printf_unsigned_value_t; -typedef long printf_signed_value_t; -#endif - -// The printf()-family functions return an `int`; it is therefore -// unnecessary/inappropriate to use size_t - often larger than int -// in practice - for non-negative related values, such as widths, -// precisions, offsets into buffers used for printing and the sizes -// of these buffers. instead, we use: -typedef unsigned int printf_size_t; -#define PRINTF_MAX_POSSIBLE_BUFFER_SIZE INT_MAX - // If we were to nitpick, this would actually be INT_MAX + 1, - // since INT_MAX is the maximum return value, which excludes the - // trailing '\0'. - -#if (PRINTF_SUPPORT_DECIMAL_SPECIFIERS || PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS) -#include -#if FLT_RADIX != 2 -#error "Non-binary-radix floating-point types are unsupported." -#endif - -/** - * This library supports taking float-point arguments up to and including - * long double's; but - it currently does _not_ support internal - * representation and manipulation of values as long doubles; the options - * are either single-precision `float` or double-precision `double`. - */ -#if PRINTF_USE_DOUBLE_INTERNALLY -typedef double floating_point_t; -#define FP_TYPE_MANT_DIG DBL_MANT_DIG -#else -typedef float floating_point_t; -#define FP_TYPE_MANT_DIG FLT_MANT_DIG -#endif - -#define NUM_DECIMAL_DIGITS_IN_INT64_T 18 - -#if FP_TYPE_MANT_DIG == 24 - -typedef uint32_t printf_fp_uint_t; -#define FP_TYPE_SIZE_IN_BITS 32 -#define FP_TYPE_EXPONENT_MASK 0xFFU -#define FP_TYPE_BASE_EXPONENT 127 -#define FP_TYPE_MAX FLT_MAX -#define FP_TYPE_MAX_10_EXP FLT_MAX_10_EXP -#define FP_TYPE_MAX_SUBNORMAL_EXPONENT_OF_10 -38 -#define FP_TYPE_MAX_SUBNORMAL_POWER_OF_10 1e-38f -#define PRINTF_MAX_PRECOMPUTED_POWER_OF_10 10 - -#elif FP_TYPE_MANT_DIG == 53 - -typedef uint64_t printf_fp_uint_t; -#define FP_TYPE_SIZE_IN_BITS 64 -#define FP_TYPE_EXPONENT_MASK 0x7FFU -#define FP_TYPE_BASE_EXPONENT 1023 -#define FP_TYPE_MAX DBL_MAX -#define FP_TYPE_MAX_10_EXP DBL_MAX_10_EXP -#define FP_TYPE_MAX_10_EXP DBL_MAX_10_EXP -#define FP_TYPE_MAX_SUBNORMAL_EXPONENT_OF_10 -308 -#define FP_TYPE_MAX_SUBNORMAL_POWER_OF_10 1e-308 -#define PRINTF_MAX_PRECOMPUTED_POWER_OF_10 NUM_DECIMAL_DIGITS_IN_INT64_T - 1 - - -#else -#error "Unsupported floating point type configuration" -#endif -#define FP_TYPE_STORED_MANTISSA_BITS (FP_TYPE_MANT_DIG - 1) - -typedef union { - printf_fp_uint_t U; - floating_point_t F; -} floating_point_with_bit_access; - -// This is unnecessary in C99, since compound initializers can be used, -// but: -// 1. Some compilers are finicky about this; -// 2. Some people may want to convert this to C89; -// 3. If you try to use it as C++, only C++20 supports compound literals -static inline floating_point_with_bit_access get_bit_access(floating_point_t x) -{ - floating_point_with_bit_access dwba; - dwba.F = x; - return dwba; -} - -static inline int get_sign_bit(floating_point_t x) -{ - // The sign is stored in the highest bit - return (int) (get_bit_access(x).U >> (FP_TYPE_SIZE_IN_BITS - 1)); -} - -static inline int get_exp2(floating_point_with_bit_access x) -{ - // The exponent in an IEEE-754 floating-point number occupies a contiguous - // sequence of bits (e.g. 52..62 for 64-bit doubles), but with a non-trivial representation: An - // unsigned offset from some negative value (with the extremal offset values reserved for - // special use). - return (int)((x.U >> FP_TYPE_STORED_MANTISSA_BITS ) & FP_TYPE_EXPONENT_MASK) - FP_TYPE_BASE_EXPONENT; -} -#define PRINTF_ABS(_x) ( (_x) > 0 ? (_x) : -(_x) ) - -#endif // (PRINTF_SUPPORT_DECIMAL_SPECIFIERS || PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS) - -// Note in particular the behavior here on LONG_MIN or LLONG_MIN; it is valid -// and well-defined, but if you're not careful you can easily trigger undefined -// behavior with -LONG_MIN or -LLONG_MIN -#define ABS_FOR_PRINTING(_x) ((printf_unsigned_value_t) ( (_x) > 0 ? (_x) : -((printf_signed_value_t)_x) )) - -// wrapper (used as buffer) for output function type -// -// One of the following must hold: -// 1. max_chars is 0 -// 2. buffer is non-null -// 3. function is non-null -// -// ... otherwise bad things will happen. -typedef struct { - void (*function)(char c, void* extra_arg); - void* extra_function_arg; - char* buffer; - printf_size_t pos; - printf_size_t max_chars; -} output_gadget_t; - -// Note: This function currently assumes it is not passed a '\0' c, -// or alternatively, that '\0' can be passed to the function in the output -// gadget. The former assumption holds within the printf library. It also -// assumes that the output gadget has been properly initialized. -static inline void putchar_via_gadget(output_gadget_t* gadget, char c) -{ - printf_size_t write_pos = gadget->pos++; - // We're _always_ increasing pos, so as to count how may characters - // _would_ have been written if not for the max_chars limitation - if (write_pos >= gadget->max_chars) { - return; - } - if (gadget->function != NULL) { - // No check for c == '\0' . - gadget->function(c, gadget->extra_function_arg); - } - else { - // it must be the case that gadget->buffer != NULL , due to the constraint - // on output_gadget_t ; and note we're relying on write_pos being non-negative. - gadget->buffer[write_pos] = c; - } -} - -// Possibly-write the string-terminating '\0' character -static inline void append_termination_with_gadget(output_gadget_t* gadget) -{ - if (gadget->function != NULL || gadget->max_chars == 0) { - return; - } - if (gadget->buffer == NULL) { - return; - } - printf_size_t null_char_pos = gadget->pos < gadget->max_chars ? gadget->pos : gadget->max_chars - 1; - gadget->buffer[null_char_pos] = '\0'; -} - -// We can't use putchar_ as is, since our output gadget -// only takes pointers to functions with an extra argument -static inline void putchar_wrapper(char c, void* unused) -{ - (void) unused; - putchar_(c); -} - -static inline output_gadget_t discarding_gadget(void) -{ - output_gadget_t gadget; - gadget.function = NULL; - gadget.extra_function_arg = NULL; - gadget.buffer = NULL; - gadget.pos = 0; - gadget.max_chars = 0; - return gadget; -} - -static inline output_gadget_t buffer_gadget(char* buffer, size_t buffer_size) -{ - printf_size_t usable_buffer_size = (buffer_size > PRINTF_MAX_POSSIBLE_BUFFER_SIZE) ? - PRINTF_MAX_POSSIBLE_BUFFER_SIZE : (printf_size_t) buffer_size; - output_gadget_t result = discarding_gadget(); - if (buffer != NULL) { - result.buffer = buffer; - result.max_chars = usable_buffer_size; - } - return result; -} - -static inline output_gadget_t function_gadget(void (*function)(char, void*), void* extra_arg) -{ - output_gadget_t result = discarding_gadget(); - result.function = function; - result.extra_function_arg = extra_arg; - result.max_chars = PRINTF_MAX_POSSIBLE_BUFFER_SIZE; - return result; -} - -static inline output_gadget_t extern_putchar_gadget(void) -{ - return function_gadget(putchar_wrapper, NULL); -} - -// internal secure strlen -// @return The length of the string (excluding the terminating 0) limited by 'maxsize' -// @note strlen uses size_t, but wes only use this function with printf_size_t -// variables - hence the signature. -static inline printf_size_t strnlen_s_(const char* str, printf_size_t maxsize) -{ - const char* s; - for (s = str; *s && maxsize--; ++s); - return (printf_size_t)(s - str); -} - - -// internal test if char is a digit (0-9) -// @return true if char is a digit -static inline bool is_digit_(char ch) -{ - return (ch >= '0') && (ch <= '9'); -} - - -// internal ASCII string to printf_size_t conversion -static printf_size_t atou_(const char** str) -{ - printf_size_t i = 0U; - while (is_digit_(**str)) { - i = i * 10U + (printf_size_t)(*((*str)++) - '0'); - } - return i; -} - - -// output the specified string in reverse, taking care of any zero-padding -static void out_rev_(output_gadget_t* output, const char* buf, printf_size_t len, printf_size_t width, printf_flags_t flags) -{ - const printf_size_t start_pos = output->pos; - - // pad spaces up to given width - if (!(flags & FLAGS_LEFT) && !(flags & FLAGS_ZEROPAD)) { - for (printf_size_t i = len; i < width; i++) { - putchar_via_gadget(output, ' '); - } - } - - // reverse string - while (len) { - putchar_via_gadget(output, buf[--len]); - } - - // append pad spaces up to given width - if (flags & FLAGS_LEFT) { - while (output->pos - start_pos < width) { - putchar_via_gadget(output, ' '); - } - } -} - - -// Invoked by print_integer after the actual number has been printed, performing necessary -// work on the number's prefix (as the number is initially printed in reverse order) -static void print_integer_finalization(output_gadget_t* output, char* buf, printf_size_t len, bool negative, numeric_base_t base, printf_size_t precision, printf_size_t width, printf_flags_t flags) -{ - printf_size_t unpadded_len = len; - - // pad with leading zeros - { - if (!(flags & FLAGS_LEFT)) { - if (width && (flags & FLAGS_ZEROPAD) && (negative || (flags & (FLAGS_PLUS | FLAGS_SPACE)))) { - width--; - } - while ((flags & FLAGS_ZEROPAD) && (len < width) && (len < PRINTF_INTEGER_BUFFER_SIZE)) { - buf[len++] = '0'; - } - } - - while ((len < precision) && (len < PRINTF_INTEGER_BUFFER_SIZE)) { - buf[len++] = '0'; - } - - if (base == BASE_OCTAL && (len > unpadded_len)) { - // Since we've written some zeros, we've satisfied the alternative format leading space requirement - flags &= ~FLAGS_HASH; - } - } - - // handle hash - if (flags & (FLAGS_HASH | FLAGS_POINTER)) { - if (!(flags & FLAGS_PRECISION) && len && ((len == precision) || (len == width))) { - // Let's take back some padding digits to fit in what will eventually - // be the format-specific prefix - if (unpadded_len < len) { - len--; // This should suffice for BASE_OCTAL - } - if (len && (base == BASE_HEX || base == BASE_BINARY) && (unpadded_len < len)) { - len--; // ... and an extra one for 0x or 0b - } - } - if ((base == BASE_HEX) && !(flags & FLAGS_UPPERCASE) && (len < PRINTF_INTEGER_BUFFER_SIZE)) { - buf[len++] = 'x'; - } - else if ((base == BASE_HEX) && (flags & FLAGS_UPPERCASE) && (len < PRINTF_INTEGER_BUFFER_SIZE)) { - buf[len++] = 'X'; - } - else if ((base == BASE_BINARY) && (len < PRINTF_INTEGER_BUFFER_SIZE)) { - buf[len++] = 'b'; - } - if (len < PRINTF_INTEGER_BUFFER_SIZE) { - buf[len++] = '0'; - } - } - - if (len < PRINTF_INTEGER_BUFFER_SIZE) { - if (negative) { - buf[len++] = '-'; - } - else if (flags & FLAGS_PLUS) { - buf[len++] = '+'; // ignore the space if the '+' exists - } - else if (flags & FLAGS_SPACE) { - buf[len++] = ' '; - } - } - - out_rev_(output, buf, len, width, flags); -} - -// An internal itoa-like function -static void print_integer(output_gadget_t* output, printf_unsigned_value_t value, bool negative, numeric_base_t base, printf_size_t precision, printf_size_t width, printf_flags_t flags) -{ - char buf[PRINTF_INTEGER_BUFFER_SIZE]; - printf_size_t len = 0U; - - if (!value) { - if ( !(flags & FLAGS_PRECISION) ) { - buf[len++] = '0'; - flags &= ~FLAGS_HASH; - // We drop this flag this since either the alternative and regular modes of the specifier - // don't differ on 0 values, or (in the case of octal) we've already provided the special - // handling for this mode. - } - else if (base == BASE_HEX) { - flags &= ~FLAGS_HASH; - // We drop this flag this since either the alternative and regular modes of the specifier - // don't differ on 0 values - } - } - else { - do { - const char digit = (char)(value % base); - buf[len++] = (char)(digit < 10 ? '0' + digit : (flags & FLAGS_UPPERCASE ? 'A' : 'a') + digit - 10); - value /= base; - } while (value && (len < PRINTF_INTEGER_BUFFER_SIZE)); - } - - print_integer_finalization(output, buf, len, negative, base, precision, width, flags); -} - -#if (PRINTF_SUPPORT_DECIMAL_SPECIFIERS || PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS) - -// Stores a fixed-precision representation of a floating-point number relative -// to a fixed precision (which cannot be determined by examining this structure) -struct floating_point_components { - int_fast64_t integral; - int_fast64_t fractional; - // ... truncation of the actual fractional part of the floating_point_t value, scaled - // by the precision value - bool is_negative; -}; - -static const floating_point_t powers_of_10[PRINTF_MAX_PRECOMPUTED_POWER_OF_10 + 1] = { - 1e00, 1e01, 1e02, 1e03, 1e04, 1e05, 1e06, 1e07, 1e08, 1e09, 1e10 -#if PRINTF_MAX_PRECOMPUTED_POWER_OF_10 > 10 - , 1e11, 1e12, 1e13, 1e14, 1e15, 1e16, 1e17 -#endif -}; - -// Note: This value does not mean that all floating-point values printed with the -// library will be correct up to this precision; it is just an upper-bound for -// avoiding buffer overruns and such -#define PRINTF_MAX_SUPPORTED_PRECISION (NUM_DECIMAL_DIGITS_IN_INT64_T - 1) - - -// Break up a floating-point number - which is known to be a finite non-negative number - -// into its base-10 parts: integral - before the decimal point, and fractional - after it. -// Taken the precision into account, but does not change it even internally. -static struct floating_point_components get_components(floating_point_t number, printf_size_t precision) -{ - struct floating_point_components number_; - number_.is_negative = get_sign_bit(number); - floating_point_t abs_number = (number_.is_negative) ? -number : number; - number_.integral = (int_fast64_t) abs_number; - floating_point_t scaled_remainder = (abs_number - (floating_point_t) number_.integral) * powers_of_10[precision]; - number_.fractional = (int_fast64_t) scaled_remainder; // for precision == 0U, this will be 0 - - floating_point_t remainder = scaled_remainder - (floating_point_t) number_.fractional; - const floating_point_t one_half = (floating_point_t) 0.5; - - if (remainder > one_half) { - ++number_.fractional; - // handle rollover, e.g. case 0.99 with precision 1 is 1.0 - if ((floating_point_t) number_.fractional >= powers_of_10[precision]) { - number_.fractional = 0; - ++number_.integral; - } - } - else if ((remainder == one_half) && (number_.fractional & 1U)) { - // Banker's rounding, i.e. round half to even: - // 1.5 -> 2, but 2.5 -> 2 - ++number_.fractional; - } - - if (precision == 0U) { - remainder = abs_number - (floating_point_t) number_.integral; - if ((remainder == one_half) && (number_.integral & 1U)) { - // Banker's rounding, i.e. round half to even: - // 1.5 -> 2, but 2.5 -> 2 - ++number_.integral; - } - } - return number_; -} - -#if PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS -struct scaling_factor { - floating_point_t raw_factor; - bool multiply; // if true, need to multiply by raw_factor; otherwise need to divide by it -}; - -static floating_point_t apply_scaling(floating_point_t num, struct scaling_factor normalization) -{ - return normalization.multiply ? num * normalization.raw_factor : num / normalization.raw_factor; -} - -static floating_point_t unapply_scaling(floating_point_t normalized, struct scaling_factor normalization) -{ -#ifdef __GNUC__ -// accounting for a static analysis bug in GCC 6.x and earlier -#pragma GCC diagnostic push -#if !defined(__has_warning) -#pragma GCC diagnostic ignored "-Wmaybe-uninitialized" -#elif __has_warning("-Wmaybe-uninitialized") -#pragma GCC diagnostic ignored "-Wmaybe-uninitialized" -#endif -#endif - return normalization.multiply ? normalized / normalization.raw_factor : normalized * normalization.raw_factor; -#ifdef __GNUC__ -#pragma GCC diagnostic pop -#endif -} - -static struct scaling_factor update_normalization(struct scaling_factor sf, floating_point_t extra_multiplicative_factor) -{ - struct scaling_factor result; - if (sf.multiply) { - result.multiply = true; - result.raw_factor = sf.raw_factor * extra_multiplicative_factor; - } - else { - int factor_exp2 = get_exp2(get_bit_access(sf.raw_factor)); - int extra_factor_exp2 = get_exp2(get_bit_access(extra_multiplicative_factor)); - - // Divide the larger-exponent raw raw_factor by the smaller - if (PRINTF_ABS(factor_exp2) > PRINTF_ABS(extra_factor_exp2)) { - result.multiply = false; - result.raw_factor = sf.raw_factor / extra_multiplicative_factor; - } - else { - result.multiply = true; - result.raw_factor = extra_multiplicative_factor / sf.raw_factor; - } - } - return result; -} - -static struct floating_point_components get_normalized_components(bool negative, printf_size_t precision, floating_point_t non_normalized, struct scaling_factor normalization, int floored_exp10) -{ - struct floating_point_components components; - components.is_negative = negative; - floating_point_t scaled = apply_scaling(non_normalized, normalization); - - bool close_to_representation_extremum = ( (-floored_exp10 + (int) precision) >= FP_TYPE_MAX_10_EXP - 1 ); - if (close_to_representation_extremum) { - // We can't have a normalization factor which also accounts for the precision, i.e. moves - // some decimal digits into the mantissa, since it's unrepresentable, or nearly unrepresentable. - // So, we'll give up early on getting extra precision... - return get_components(negative ? -scaled : scaled, precision); - } - components.integral = (int_fast64_t) scaled; - floating_point_t remainder = non_normalized - unapply_scaling((floating_point_t) components.integral, normalization); - floating_point_t prec_power_of_10 = powers_of_10[precision]; - struct scaling_factor account_for_precision = update_normalization(normalization, prec_power_of_10); - floating_point_t scaled_remainder = apply_scaling(remainder, account_for_precision); - floating_point_t rounding_threshold = 0.5; - - components.fractional = (int_fast64_t) scaled_remainder; // when precision == 0, the assigned value should be 0 - scaled_remainder -= (floating_point_t) components.fractional; //when precision == 0, this will not change scaled_remainder - - components.fractional += (scaled_remainder >= rounding_threshold); - if (scaled_remainder == rounding_threshold) { - // banker's rounding: Round towards the even number (making the mean error 0) - components.fractional &= ~((int_fast64_t) 0x1); - } - // handle rollover, e.g. the case of 0.99 with precision 1 becoming (0,100), - // and must then be corrected into (1, 0). - // Note: for precision = 0, this will "translate" the rounding effect from - // the fractional part to the integral part where it should actually be - // felt (as prec_power_of_10 is 1) - if ((floating_point_t) components.fractional >= prec_power_of_10) { - components.fractional = 0; - ++components.integral; - } - return components; -} -#endif // PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS - -static void print_broken_up_decimal( - struct floating_point_components number_, output_gadget_t* output, printf_size_t precision, - printf_size_t width, printf_flags_t flags, char *buf, printf_size_t len) -{ - if (precision != 0U) { - // do fractional part, as an unsigned number - - printf_size_t count = precision; - - // %g/%G mandates we skip the trailing 0 digits... - if ((flags & FLAGS_ADAPT_EXP) && !(flags & FLAGS_HASH) && (number_.fractional > 0)) { - while(true) { - int_fast64_t digit = number_.fractional % 10U; - if (digit != 0) { - break; - } - --count; - number_.fractional /= 10U; - - } - // ... and even the decimal point if there are no - // non-zero fractional part digits (see below) - } - - if (number_.fractional > 0 || !(flags & FLAGS_ADAPT_EXP) || (flags & FLAGS_HASH) ) { - while (len < PRINTF_DECIMAL_BUFFER_SIZE) { - --count; - buf[len++] = (char)('0' + number_.fractional % 10U); - if (!(number_.fractional /= 10U)) { - break; - } - } - // add extra 0s - while ((len < PRINTF_DECIMAL_BUFFER_SIZE) && (count > 0U)) { - buf[len++] = '0'; - --count; - } - if (len < PRINTF_DECIMAL_BUFFER_SIZE) { - buf[len++] = '.'; - } - } - } - else { - if ((flags & FLAGS_HASH) && (len < PRINTF_DECIMAL_BUFFER_SIZE)) { - buf[len++] = '.'; - } - } - - // Write the integer part of the number (it comes after the fractional - // since the character order is reversed) - while (len < PRINTF_DECIMAL_BUFFER_SIZE) { - buf[len++] = (char)('0' + (number_.integral % 10)); - if (!(number_.integral /= 10)) { - break; - } - } - - // pad leading zeros - if (!(flags & FLAGS_LEFT) && (flags & FLAGS_ZEROPAD)) { - if (width && (number_.is_negative || (flags & (FLAGS_PLUS | FLAGS_SPACE)))) { - width--; - } - while ((len < width) && (len < PRINTF_DECIMAL_BUFFER_SIZE)) { - buf[len++] = '0'; - } - } - - if (len < PRINTF_DECIMAL_BUFFER_SIZE) { - if (number_.is_negative) { - buf[len++] = '-'; - } - else if (flags & FLAGS_PLUS) { - buf[len++] = '+'; // ignore the space if the '+' exists - } - else if (flags & FLAGS_SPACE) { - buf[len++] = ' '; - } - } - - out_rev_(output, buf, len, width, flags); -} - -// internal ftoa for fixed decimal floating point -static void print_decimal_number(output_gadget_t* output, floating_point_t number, printf_size_t precision, printf_size_t width, printf_flags_t flags, char* buf, printf_size_t len) -{ - struct floating_point_components value_ = get_components(number, precision); - print_broken_up_decimal(value_, output, precision, width, flags, buf, len); -} - -#if PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS - -// A floor function - but one which only works for numbers whose -// floor value is representable by an int. -static int bastardized_floor(floating_point_t x) -{ - if (x >= 0) { return (int) x; } - int n = (int) x; - return ( ((floating_point_t) n) == x ) ? n : n-1; -} - -// Computes the base-10 logarithm of the input number - which must be an actual -// positive number (not infinity or NaN, nor a sub-normal) -static floating_point_t log10_of_positive(floating_point_t positive_number) -{ - // The implementation follows David Gay (https://www.ampl.com/netlib/fp/dtoa.c). - // - // Since log_10 ( M * 2^x ) = log_10(M) + x , we can separate the components of - // our input number, and need only solve log_10(M) for M between 1 and 2 (as - // the base-2 mantissa is always 1-point-something). In that limited range, a - // Taylor series expansion of log10(x) should serve us well enough; and we'll - // take the mid-point, 1.5, as the point of expansion. - - floating_point_with_bit_access dwba = get_bit_access(positive_number); - // based on the algorithm by David Gay (https://www.ampl.com/netlib/fp/dtoa.c) - int exp2 = get_exp2(dwba); - // drop the exponent, so dwba.F comes into the range [1,2) - dwba.U = (dwba.U & (((printf_fp_uint_t) (1) << FP_TYPE_STORED_MANTISSA_BITS) - 1U)) | - ((printf_fp_uint_t) FP_TYPE_BASE_EXPONENT << FP_TYPE_STORED_MANTISSA_BITS); - floating_point_t z = (dwba.F - (floating_point_t) 1.5); - return ( - // Taylor expansion around 1.5: - (floating_point_t) 0.1760912590556812420 // Expansion term 0: ln(1.5) / ln(10) - + z * (floating_point_t) 0.2895296546021678851 // Expansion term 1: (M - 1.5) * 2/3 / ln(10) -#if PRINTF_LOG10_TAYLOR_TERMS > 2 - - z*z * (floating_point_t) 0.0965098848673892950 // Expansion term 2: (M - 1.5)^2 * 2/9 / ln(10) -#if PRINTF_LOG10_TAYLOR_TERMS > 3 - + z*z*z * (floating_point_t) 0.0428932821632841311 // Expansion term 2: (M - 1.5)^3 * 8/81 / ln(10) -#endif -#endif - // exact log_2 of the exponent x, with logarithm base change - + (floating_point_t) exp2 * (floating_point_t) 0.30102999566398119521 // = exp2 * log_10(2) = exp2 * ln(2)/ln(10) - ); -} - - -static floating_point_t pow10_of_int(int floored_exp10) -{ - // A crude hack for avoiding undesired behavior with barely-normal or slightly-subnormal values. - if (floored_exp10 == FP_TYPE_MAX_SUBNORMAL_EXPONENT_OF_10) { - return FP_TYPE_MAX_SUBNORMAL_POWER_OF_10; - } - // Compute 10^(floored_exp10) but (try to) make sure that doesn't overflow - floating_point_with_bit_access dwba; - int exp2 = bastardized_floor((floating_point_t) (floored_exp10 * 3.321928094887362 + 0.5)); - const floating_point_t z = (floating_point_t) (floored_exp10 * 2.302585092994046 - exp2 * 0.6931471805599453); - const floating_point_t z2 = z * z; - dwba.U = ((printf_fp_uint_t)(exp2) + FP_TYPE_BASE_EXPONENT) << FP_TYPE_STORED_MANTISSA_BITS; - // compute exp(z) using continued fractions, - // see https://en.wikipedia.org/wiki/Exponential_function#Continued_fractions_for_ex - dwba.F *= 1 + 2 * z / (2 - z + (z2 / (6 + (z2 / (10 + z2 / 14))))); - return dwba.F; -} - -static void print_exponential_number(output_gadget_t* output, floating_point_t number, printf_size_t precision, printf_size_t width, printf_flags_t flags, char* buf, printf_size_t len) -{ - const bool negative = get_sign_bit(number); - // This number will decrease gradually (by factors of 10) as we "extract" the exponent out of it - floating_point_t abs_number = negative ? -number : number; - - int floored_exp10; - bool abs_exp10_covered_by_powers_table; - struct scaling_factor normalization; - - - // Determine the decimal exponent - if (abs_number == (floating_point_t) 0.0) { - // TODO: This is a special-case for 0.0 (and -0.0); but proper handling is required for denormals more generally. - floored_exp10 = 0; // ... and no need to set a normalization factor or check the powers table - } - else { - floating_point_t exp10 = log10_of_positive(abs_number); - floored_exp10 = bastardized_floor(exp10); - floating_point_t p10 = pow10_of_int(floored_exp10); - // correct for rounding errors - if (abs_number < p10) { - floored_exp10--; - p10 /= 10; - } - abs_exp10_covered_by_powers_table = PRINTF_ABS(floored_exp10) < PRINTF_MAX_PRECOMPUTED_POWER_OF_10; - normalization.raw_factor = abs_exp10_covered_by_powers_table ? powers_of_10[PRINTF_ABS(floored_exp10)] : p10; - } - - // We now begin accounting for the widths of the two parts of our printed field: - // the decimal part after decimal exponent extraction, and the base-10 exponent part. - // For both of these, the value of 0 has a special meaning, but not the same one: - // a 0 exponent-part width means "don't print the exponent"; a 0 decimal-part width - // means "use as many characters as necessary". - - bool fall_back_to_decimal_only_mode = false; - if (flags & FLAGS_ADAPT_EXP) { - int required_significant_digits = (precision == 0) ? 1 : (int) precision; - // Should we want to fall-back to "%f" mode, and only print the decimal part? - fall_back_to_decimal_only_mode = (floored_exp10 >= -4 && floored_exp10 < required_significant_digits); - // Now, let's adjust the precision - // This also decided how we adjust the precision value - as in "%g" mode, - // "precision" is the number of _significant digits_, and this is when we "translate" - // the precision value to an actual number of decimal digits. - int precision_ = fall_back_to_decimal_only_mode ? - (int) precision - 1 - floored_exp10 : - (int) precision - 1; // the presence of the exponent ensures only one significant digit comes before the decimal point - precision = (precision_ > 0 ? (unsigned) precision_ : 0U); - flags |= FLAGS_PRECISION; // make sure print_broken_up_decimal respects our choice above - } - -#ifdef __GNUC__ -// accounting for a static analysis bug in GCC 6.x and earlier -#pragma GCC diagnostic push -#if !defined(__has_warning) -#pragma GCC diagnostic ignored "-Wmaybe-uninitialized" -#elif __has_warning("-Wmaybe-uninitialized") -#pragma GCC diagnostic ignored "-Wmaybe-uninitialized" -#endif -#endif - normalization.multiply = (floored_exp10 < 0 && abs_exp10_covered_by_powers_table); -#ifdef __GNUC__ -#pragma GCC diagnostic pop -#endif - bool should_skip_normalization = (fall_back_to_decimal_only_mode || floored_exp10 == 0); - struct floating_point_components decimal_part_components = - should_skip_normalization ? - get_components(negative ? -abs_number : abs_number, precision) : - get_normalized_components(negative, precision, abs_number, normalization, floored_exp10); - - // Account for roll-over, e.g. rounding from 9.99 to 100.0 - which effects - // the exponent and may require additional tweaking of the parts - if (fall_back_to_decimal_only_mode) { - if ((flags & FLAGS_ADAPT_EXP) && floored_exp10 >= -1 && decimal_part_components.integral == powers_of_10[floored_exp10 + 1]) { - floored_exp10++; // Not strictly necessary, since floored_exp10 is no longer really used - if (precision > 0U) { precision--; } - // ... and it should already be the case that decimal_part_components.fractional == 0 - } - // TODO: What about rollover strictly within the fractional part? - } - else { - if (decimal_part_components.integral >= 10) { - floored_exp10++; - decimal_part_components.integral = 1; - decimal_part_components.fractional = 0; - } - } - - // the floored_exp10 format is "E%+03d" and largest possible floored_exp10 value for a 64-bit double - // is "307" (for 2^1023), so we set aside 4-5 characters overall - printf_size_t exp10_part_width = fall_back_to_decimal_only_mode ? 0U : (PRINTF_ABS(floored_exp10) < 100) ? 4U : 5U; - - printf_size_t decimal_part_width = - ((flags & FLAGS_LEFT) && exp10_part_width) ? - // We're padding on the right, so the width constraint is the exponent part's - // problem, not the decimal part's, so we'll use as many characters as we need: - 0U : - // We're padding on the left; so the width constraint is the decimal part's - // problem. Well, can both the decimal part and the exponent part fit within our overall width? - ((width > exp10_part_width) ? - // Yes, so we limit our decimal part's width. - // (Note this is trivially valid even if we've fallen back to "%f" mode) - width - exp10_part_width : - // No; we just give up on any restriction on the decimal part and use as many - // characters as we need - 0U); - - const printf_size_t printed_exponential_start_pos = output->pos; - print_broken_up_decimal(decimal_part_components, output, precision, decimal_part_width, flags, buf, len); - - if (! fall_back_to_decimal_only_mode) { - putchar_via_gadget(output, (flags & FLAGS_UPPERCASE) ? 'E' : 'e'); - print_integer(output, - ABS_FOR_PRINTING(floored_exp10), - floored_exp10 < 0, 10, 0, exp10_part_width - 1, - FLAGS_ZEROPAD | FLAGS_PLUS); - if (flags & FLAGS_LEFT) { - // We need to right-pad with spaces to meet the width requirement - while (output->pos - printed_exponential_start_pos < width) { - putchar_via_gadget(output, ' '); - } - } - } -} -#endif // PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS - -static void print_floating_point(output_gadget_t* output, floating_point_t value, printf_size_t precision, printf_size_t width, printf_flags_t flags, bool prefer_exponential) -{ - char buf[PRINTF_DECIMAL_BUFFER_SIZE]; - printf_size_t len = 0U; - - // test for special values - if (value != value) { - out_rev_(output, "nan", 3, width, flags); - return; - } - if (value < -FP_TYPE_MAX) { - out_rev_(output, "fni-", 4, width, flags); - return; - } - if (value > FP_TYPE_MAX) { - out_rev_(output, (flags & FLAGS_PLUS) ? "fni+" : "fni", (flags & FLAGS_PLUS) ? 4U : 3U, width, flags); - return; - } - - if (!prefer_exponential && - ((value > PRINTF_FLOAT_NOTATION_THRESHOLD) || (value < -PRINTF_FLOAT_NOTATION_THRESHOLD))) { - // The required behavior of standard printf is to print _every_ integral-part digit -- which could mean - // printing hundreds of characters, overflowing any fixed internal buffer and necessitating a more complicated - // implementation. -#if PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS - print_exponential_number(output, value, precision, width, flags, buf, len); -#endif - return; - } - - // set default precision, if not set explicitly - if (!(flags & FLAGS_PRECISION)) { - precision = PRINTF_DEFAULT_FLOAT_PRECISION; - } - - // limit precision so that our integer holding the fractional part does not overflow - while ((len < PRINTF_DECIMAL_BUFFER_SIZE) && (precision > PRINTF_MAX_SUPPORTED_PRECISION)) { - buf[len++] = '0'; // This respects the precision in terms of result length only - precision--; - } - -#if PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS - if (prefer_exponential) - print_exponential_number(output, value, precision, width, flags, buf, len); - else -#endif - print_decimal_number(output, value, precision, width, flags, buf, len); -} - -#endif // (PRINTF_SUPPORT_DECIMAL_SPECIFIERS || PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS) - -// Advances the format pointer past the flags, and returns the parsed flags -// due to the characters passed -static printf_flags_t parse_flags(const char** format) -{ - printf_flags_t flags = 0U; - do { - switch (**format) { - case '0': flags |= FLAGS_ZEROPAD; (*format)++; break; - case '-': flags |= FLAGS_LEFT; (*format)++; break; - case '+': flags |= FLAGS_PLUS; (*format)++; break; - case ' ': flags |= FLAGS_SPACE; (*format)++; break; - case '#': flags |= FLAGS_HASH; (*format)++; break; - default : return flags; - } - } while (true); -} - -static inline void format_string_loop(output_gadget_t* output, const char* format, va_list args) -{ -#if PRINTF_CHECK_FOR_NUL_IN_FORMAT_SPECIFIER -#define ADVANCE_IN_FORMAT_STRING(cptr_) do { (cptr_)++; if (!*(cptr_)) return; } while(0) -#else -#define ADVANCE_IN_FORMAT_STRING(cptr_) (cptr_)++ -#endif - - - while (*format) - { - if (*format != '%') { - // A regular content character - putchar_via_gadget(output, *format); - format++; - continue; - } - // We're parsing a format specifier: %[flags][width][.precision][length] - ADVANCE_IN_FORMAT_STRING(format); - - printf_flags_t flags = parse_flags(&format); - - // evaluate width field - printf_size_t width = 0U; - if (is_digit_(*format)) { - width = (printf_size_t) atou_(&format); - } - else if (*format == '*') { - const int w = va_arg(args, int); - if (w < 0) { - flags |= FLAGS_LEFT; // reverse padding - width = (printf_size_t)-w; - } - else { - width = (printf_size_t)w; - } - ADVANCE_IN_FORMAT_STRING(format); - } - - // evaluate precision field - printf_size_t precision = 0U; - if (*format == '.') { - flags |= FLAGS_PRECISION; - ADVANCE_IN_FORMAT_STRING(format); - if (is_digit_(*format)) { - precision = (printf_size_t) atou_(&format); - } - else if (*format == '*') { - const int precision_ = va_arg(args, int); - precision = precision_ > 0 ? (printf_size_t) precision_ : 0U; - ADVANCE_IN_FORMAT_STRING(format); - } - } - - // evaluate length field - switch (*format) { -#ifdef PRINTF_SUPPORT_MSVC_STYLE_INTEGER_SPECIFIERS - case 'I' : { - ADVANCE_IN_FORMAT_STRING(format); - // Greedily parse for size in bits: 8, 16, 32 or 64 - switch(*format) { - case '8': flags |= FLAGS_INT8; - ADVANCE_IN_FORMAT_STRING(format); - break; - case '1': - ADVANCE_IN_FORMAT_STRING(format); - if (*format == '6') { format++; flags |= FLAGS_INT16; } - break; - case '3': - ADVANCE_IN_FORMAT_STRING(format); - if (*format == '2') { ADVANCE_IN_FORMAT_STRING(format); flags |= FLAGS_INT32; } - break; - case '6': - ADVANCE_IN_FORMAT_STRING(format); - if (*format == '4') { ADVANCE_IN_FORMAT_STRING(format); flags |= FLAGS_INT64; } - break; - default: break; - } - break; - } -#endif - case 'l' : - flags |= FLAGS_LONG; - ADVANCE_IN_FORMAT_STRING(format); - if (*format == 'l') { - flags |= FLAGS_LONG_LONG; - ADVANCE_IN_FORMAT_STRING(format); - } - break; - case 'L' : - flags |= FLAGS_LONG_DOUBLE; - ADVANCE_IN_FORMAT_STRING(format); - break; - case 'h' : - flags |= FLAGS_SHORT; - ADVANCE_IN_FORMAT_STRING(format); - if (*format == 'h') { - flags |= FLAGS_CHAR; - ADVANCE_IN_FORMAT_STRING(format); - } - break; - case 't' : - flags |= (sizeof(ptrdiff_t) <= sizeof(int) ) ? FLAGS_INT : (sizeof(ptrdiff_t) == sizeof(long)) ? FLAGS_LONG : FLAGS_LONG_LONG; - ADVANCE_IN_FORMAT_STRING(format); - break; - case 'j' : - flags |= (sizeof(intmax_t) == sizeof(long) ? FLAGS_LONG : FLAGS_LONG_LONG); - ADVANCE_IN_FORMAT_STRING(format); - break; - case 'z' : - flags |= (sizeof(size_t) <= sizeof(int) ) ? FLAGS_INT : (sizeof(size_t) == sizeof(long)) ? FLAGS_LONG : FLAGS_LONG_LONG; - ADVANCE_IN_FORMAT_STRING(format); - break; - default: - break; - } - - // evaluate specifier - switch (*format) { - case 'd' : - case 'i' : - case 'u' : - case 'x' : - case 'X' : - case 'o' : - case 'b' : { - - if (*format == 'd' || *format == 'i') { - flags |= FLAGS_SIGNED; - } - - numeric_base_t base; - if (*format == 'x' || *format == 'X') { - base = BASE_HEX; - } - else if (*format == 'o') { - base = BASE_OCTAL; - } - else if (*format == 'b') { - base = BASE_BINARY; - } - else { - base = BASE_DECIMAL; - flags &= ~FLAGS_HASH; // decimal integers have no alternative presentation - } - - if (*format == 'X') { - flags |= FLAGS_UPPERCASE; - } - - format++; - // ignore '0' flag when precision is given - if (flags & FLAGS_PRECISION) { - flags &= ~FLAGS_ZEROPAD; - } - - if (flags & FLAGS_SIGNED) { - // A signed specifier: d, i or possibly I + bit size if enabled - - if (flags & FLAGS_LONG_LONG) { -#if PRINTF_SUPPORT_LONG_LONG - const long long value = va_arg(args, long long); - print_integer(output, ABS_FOR_PRINTING(value), value < 0, base, precision, width, flags); -#endif - } - else if (flags & FLAGS_LONG) { - const long value = va_arg(args, long); - print_integer(output, ABS_FOR_PRINTING(value), value < 0, base, precision, width, flags); - } - else { - // We never try to interpret the argument as something potentially-smaller than int, - // due to integer promotion rules: Even if the user passed a short int, short unsigned - // etc. - these will come in after promotion, as int's (or unsigned for the case of - // short unsigned when it has the same size as int) - const int value = - (flags & FLAGS_CHAR) ? (signed char) va_arg(args, int) : - (flags & FLAGS_SHORT) ? (short int) va_arg(args, int) : - va_arg(args, int); - print_integer(output, ABS_FOR_PRINTING(value), value < 0, base, precision, width, flags); - } - } - else { - // An unsigned specifier: u, x, X, o, b - - flags &= ~(FLAGS_PLUS | FLAGS_SPACE); - - if (flags & FLAGS_LONG_LONG) { -#if PRINTF_SUPPORT_LONG_LONG - print_integer(output, (printf_unsigned_value_t) va_arg(args, unsigned long long), false, base, precision, width, flags); -#endif - } - else if (flags & FLAGS_LONG) { - print_integer(output, (printf_unsigned_value_t) va_arg(args, unsigned long), false, base, precision, width, flags); - } - else { - const unsigned int value = - (flags & FLAGS_CHAR) ? (unsigned char)va_arg(args, unsigned int) : - (flags & FLAGS_SHORT) ? (unsigned short int)va_arg(args, unsigned int) : - va_arg(args, unsigned int); - print_integer(output, (printf_unsigned_value_t) value, false, base, precision, width, flags); - } - } - break; - } -#if PRINTF_SUPPORT_DECIMAL_SPECIFIERS - case 'f' : - case 'F' : { - floating_point_t value = (floating_point_t) (flags & FLAGS_LONG_DOUBLE ? va_arg(args, long double) : va_arg(args, double)); - if (*format == 'F') flags |= FLAGS_UPPERCASE; - print_floating_point(output, value, precision, width, flags, PRINTF_PREFER_DECIMAL); - format++; - break; - } -#endif -#if PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS - case 'e': - case 'E': - case 'g': - case 'G': { - floating_point_t value = (floating_point_t) (flags & FLAGS_LONG_DOUBLE ? va_arg(args, long double) : va_arg(args, double)); - if ((*format == 'g')||(*format == 'G')) flags |= FLAGS_ADAPT_EXP; - if ((*format == 'E')||(*format == 'G')) flags |= FLAGS_UPPERCASE; - print_floating_point(output, value, precision, width, flags, PRINTF_PREFER_EXPONENTIAL); - format++; - break; - } -#endif // PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS - case 'c' : { - printf_size_t l = 1U; - // pre padding - if (!(flags & FLAGS_LEFT)) { - while (l++ < width) { - putchar_via_gadget(output, ' '); - } - } - // char output - putchar_via_gadget(output, (char) va_arg(args, int) ); - // post padding - if (flags & FLAGS_LEFT) { - while (l++ < width) { - putchar_via_gadget(output, ' '); - } - } - format++; - break; - } - - case 's' : { - const char* p = va_arg(args, char*); - if (p == NULL) { - out_rev_(output, ")llun(", 6, width, flags); - } - else { - printf_size_t l = strnlen_s_(p, precision ? precision : PRINTF_MAX_POSSIBLE_BUFFER_SIZE); - // pre padding - if (flags & FLAGS_PRECISION) { - l = (l < precision ? l : precision); - } - if (!(flags & FLAGS_LEFT)) { - while (l++ < width) { - putchar_via_gadget(output, ' '); - } - } - // string output - while ((*p != 0) && (!(flags & FLAGS_PRECISION) || precision)) { - putchar_via_gadget(output, *(p++)); - --precision; - } - // post padding - if (flags & FLAGS_LEFT) { - while (l++ < width) { - putchar_via_gadget(output, ' '); - } - } - } - format++; - break; - } - - case 'p' : { - width = sizeof(void*) * 2U + 2; // 2 hex chars per byte + the "0x" prefix - flags |= FLAGS_ZEROPAD | FLAGS_POINTER; - uintptr_t value = (uintptr_t)va_arg(args, void*); - (value == (uintptr_t) NULL) ? - out_rev_(output, ")lin(", 5, width, flags) : - print_integer(output, (printf_unsigned_value_t) value, false, BASE_HEX, precision, width, flags); - format++; - break; - } - - case '%' : - putchar_via_gadget(output, '%'); - format++; - break; - - // Many people prefer to disable support for %n, as it lets the caller - // engineer a write to an arbitrary location, of a value the caller - // effectively controls - which could be a security concern in some cases. -#if PRINTF_SUPPORT_WRITEBACK_SPECIFIER - case 'n' : { - if (flags & FLAGS_CHAR) *(va_arg(args, char*)) = (char) output->pos; - else if (flags & FLAGS_SHORT) *(va_arg(args, short*)) = (short) output->pos; - else if (flags & FLAGS_LONG) *(va_arg(args, long*)) = (long) output->pos; -#if PRINTF_SUPPORT_LONG_LONG - else if (flags & FLAGS_LONG_LONG) *(va_arg(args, long long*)) = (long long int) output->pos; -#endif // PRINTF_SUPPORT_LONG_LONG - else *(va_arg(args, int*)) = (int) output->pos; - format++; - break; - } -#endif // PRINTF_SUPPORT_WRITEBACK_SPECIFIER - - default : - putchar_via_gadget(output, *format); - format++; - break; - } - } -} - -// internal vsnprintf - used for implementing _all library functions -static int vsnprintf_impl(output_gadget_t* output, const char* format, va_list args) -{ - // Note: The library only calls vsnprintf_impl() with output->pos being 0. However, it is - // possible to call this function with a non-zero pos value for some "remedial printing". - format_string_loop(output, format, args); - - // termination - append_termination_with_gadget(output); - - // return written chars without terminating \0 - return (int)output->pos; -} - -/////////////////////////////////////////////////////////////////////////////// - -int vprintf_(const char* format, va_list arg) -{ - output_gadget_t gadget = extern_putchar_gadget(); - return vsnprintf_impl(&gadget, format, arg); -} - -int vsnprintf_(char* s, size_t n, const char* format, va_list arg) -{ - output_gadget_t gadget = buffer_gadget(s, n); - return vsnprintf_impl(&gadget, format, arg); -} - -int vsprintf_(char* s, const char* format, va_list arg) -{ - return vsnprintf_(s, PRINTF_MAX_POSSIBLE_BUFFER_SIZE, format, arg); -} - -int vfctprintf(void (*out)(char c, void* extra_arg), void* extra_arg, const char* format, va_list arg) -{ - if (out == NULL) { return 0; } - output_gadget_t gadget = function_gadget(out, extra_arg); - return vsnprintf_impl(&gadget, format, arg); -} - -int printf_(const char* format, ...) -{ - va_list args; - va_start(args, format); - const int ret = vprintf_(format, args); - va_end(args); - return ret; -} - -int sprintf_(char* s, const char* format, ...) -{ - va_list args; - va_start(args, format); - const int ret = vsprintf_(s, format, args); - va_end(args); - return ret; -} - -int snprintf_(char* s, size_t n, const char* format, ...) -{ - va_list args; - va_start(args, format); - const int ret = vsnprintf_(s, n, format, args); - va_end(args); - return ret; -} - -int fctprintf(void (*out)(char c, void* extra_arg), void* extra_arg, const char* format, ...) -{ - va_list args; - va_start(args, format); - const int ret = vfctprintf(out, extra_arg, format, args); - va_end(args); - return ret; -} - diff --git a/kernel/printf/printf.c b/kernel/printf/printf.c new file mode 120000 index 0000000..eb73a6e --- /dev/null +++ b/kernel/printf/printf.c @@ -0,0 +1 @@ +../../share/printf/printf.c \ No newline at end of file diff --git a/kernel/printf/printf.h b/kernel/printf/printf.h deleted file mode 100644 index 48cbade..0000000 --- a/kernel/printf/printf.h +++ /dev/null @@ -1,236 +0,0 @@ -/** - * @author (c) Eyal Rozenberg - * 2021-2023, 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 -# include -extern "C" { -#else -# include -# include -#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_SOFT -#define PRINTF_ALIAS_STANDARD_FUNCTION_NAMES_SOFT 0 -#endif - -#ifndef PRINTF_ALIAS_STANDARD_FUNCTION_NAMES_HARD -#define PRINTF_ALIAS_STANDARD_FUNCTION_NAMES_HARD 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 it, 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 - * @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_ diff --git a/kernel/printf/printf.h b/kernel/printf/printf.h new file mode 120000 index 0000000..051f69c --- /dev/null +++ b/kernel/printf/printf.h @@ -0,0 +1 @@ +../../share/printf/printf.h \ No newline at end of file diff --git a/kernel/printf/printf_config.h b/kernel/printf/printf_config.h deleted file mode 100644 index 2979c39..0000000 --- a/kernel/printf/printf_config.h +++ /dev/null @@ -1,2 +0,0 @@ -#define PRINTF_SUPPORT_DECIMAL_SPECIFIERS 0 -#define PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS 0 diff --git a/kernel/printf/printf_config.h b/kernel/printf/printf_config.h new file mode 120000 index 0000000..a64d127 --- /dev/null +++ b/kernel/printf/printf_config.h @@ -0,0 +1 @@ +../../share/printf/printf_config.h \ No newline at end of file diff --git a/share/printf/printf.c b/share/printf/printf.c new file mode 100644 index 0000000..e47bac6 --- /dev/null +++ b/share/printf/printf.c @@ -0,0 +1,1485 @@ +/** + * @author (c) Eyal Rozenberg + * 2021-2023, 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. The original code for exponential specifiers was + * contributed by Martijn Jasperse . + * + * @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 + * 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. + */ + +// Define this globally (e.g. gcc -DPRINTF_INCLUDE_CONFIG_H=1 ...) to include the +// printf_config.h header file +#if PRINTF_INCLUDE_CONFIG_H +#include "printf_config.h" +#endif + +#include + +#ifdef __cplusplus +#include +#include +#else +#include +#include +#include +#endif // __cplusplus + +#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 + + +// 'ntoa' conversion buffer size, this must be big enough to hold one converted +// numeric number including padded zeros (dynamically created on stack) +#ifndef PRINTF_INTEGER_BUFFER_SIZE +#define PRINTF_INTEGER_BUFFER_SIZE 32 +#endif + +// size of the fixed (on-stack) buffer for printing individual decimal numbers. +// this must be big enough to hold one converted floating-point value including +// padded zeros. +#ifndef PRINTF_DECIMAL_BUFFER_SIZE +#define PRINTF_DECIMAL_BUFFER_SIZE 32 +#endif + +// Support for the decimal notation floating point conversion specifiers (%f, %F) +#ifndef PRINTF_SUPPORT_DECIMAL_SPECIFIERS +#define PRINTF_SUPPORT_DECIMAL_SPECIFIERS 1 +#endif + +// Support for the exponential notation floating point conversion specifiers (%e, %g, %E, %G) +#ifndef PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS +#define PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS 1 +#endif + +// Support for the length write-back specifier (%n) +#ifndef PRINTF_SUPPORT_WRITEBACK_SPECIFIER +#define PRINTF_SUPPORT_WRITEBACK_SPECIFIER 1 +#endif + +// Default precision for the floating point conversion specifiers (the C standard sets this at 6) +#ifndef PRINTF_DEFAULT_FLOAT_PRECISION +#define PRINTF_DEFAULT_FLOAT_PRECISION 6 +#endif + +// Default choice of type to use for internal floating-point computations +#ifndef PRINTF_USE_DOUBLE_INTERNALLY +#define PRINTF_USE_DOUBLE_INTERNALLY 1 +#endif + +// According to the C languages standard, printf() and related functions must be able to print any +// integral number in floating-point notation, regardless of length, when using the %f specifier - +// possibly hundreds of characters, potentially overflowing your buffers. In this implementation, +// all values beyond this threshold are switched to exponential notation. +#ifndef PRINTF_MAX_INTEGRAL_DIGITS_FOR_DECIMAL +#define PRINTF_MAX_INTEGRAL_DIGITS_FOR_DECIMAL 9 +#endif + +// Support for the long long integral types (with the ll, z and t length modifiers for specifiers +// %d,%i,%o,%x,%X,%u, and with the %p specifier). +#ifndef PRINTF_SUPPORT_LONG_LONG +#define PRINTF_SUPPORT_LONG_LONG 1 +#endif + +// The number of terms in a Taylor series expansion of log_10(x) to +// use for approximation - including the power-zero term (i.e. the +// value at the point of expansion). +#ifndef PRINTF_LOG10_TAYLOR_TERMS +#define PRINTF_LOG10_TAYLOR_TERMS 4 +#endif + +#if PRINTF_LOG10_TAYLOR_TERMS <= 1 +#error "At least one non-constant Taylor expansion is necessary for the log10() calculation" +#endif + +// Be extra-safe, and don't assume format specifiers are completed correctly +// before the format string end. +#ifndef PRINTF_CHECK_FOR_NUL_IN_FORMAT_SPECIFIER +#define PRINTF_CHECK_FOR_NUL_IN_FORMAT_SPECIFIER 1 +#endif + +#define PRINTF_PREFER_DECIMAL false +#define PRINTF_PREFER_EXPONENTIAL true + +/////////////////////////////////////////////////////////////////////////////// + +// The following will convert the number-of-digits into an exponential-notation literal +#define PRINTF_CONCATENATE(s1, s2) s1##s2 +#define PRINTF_EXPAND_THEN_CONCATENATE(s1, s2) PRINTF_CONCATENATE(s1, s2) +#define PRINTF_FLOAT_NOTATION_THRESHOLD ((floating_point_t) PRINTF_EXPAND_THEN_CONCATENATE(1e,PRINTF_MAX_INTEGRAL_DIGITS_FOR_DECIMAL)) + +// internal flag definitions +#define FLAGS_ZEROPAD (1U << 0U) +#define FLAGS_LEFT (1U << 1U) +#define FLAGS_PLUS (1U << 2U) +#define FLAGS_SPACE (1U << 3U) +#define FLAGS_HASH (1U << 4U) +#define FLAGS_UPPERCASE (1U << 5U) +#define FLAGS_CHAR (1U << 6U) +#define FLAGS_SHORT (1U << 7U) +#define FLAGS_INT (1U << 8U) + // Only used with PRINTF_SUPPORT_MSVC_STYLE_INTEGER_SPECIFIERS +#define FLAGS_LONG (1U << 9U) +#define FLAGS_LONG_LONG (1U << 10U) +#define FLAGS_PRECISION (1U << 11U) +#define FLAGS_ADAPT_EXP (1U << 12U) +#define FLAGS_POINTER (1U << 13U) + // Note: Similar, but not identical, effect as FLAGS_HASH +#define FLAGS_SIGNED (1U << 14U) +#define FLAGS_LONG_DOUBLE (1U << 15U) + // Only used with PRINTF_SUPPORT_MSVC_STYLE_INTEGER_SPECIFIERS + +#ifdef PRINTF_SUPPORT_MSVC_STYLE_INTEGER_SPECIFIERS + +#define FLAGS_INT8 FLAGS_CHAR + + +#if (SHRT_MAX == 32767LL) +#define FLAGS_INT16 FLAGS_SHORT +#elif (INT_MAX == 32767LL) +#define FLAGS_INT16 FLAGS_INT +#elif (LONG_MAX == 32767LL) +#define FLAGS_INT16 FLAGS_LONG +#elif (LLONG_MAX == 32767LL) +#define FLAGS_INT16 FLAGS_LONG_LONG +#else +#error "No basic integer type has a size of 16 bits exactly" +#endif + +#if (SHRT_MAX == 2147483647LL) +#define FLAGS_INT32 FLAGS_SHORT +#elif (INT_MAX == 2147483647LL) +#define FLAGS_INT32 FLAGS_INT +#elif (LONG_MAX == 2147483647LL) +#define FLAGS_INT32 FLAGS_LONG +#elif (LLONG_MAX == 2147483647LL) +#define FLAGS_INT32 FLAGS_LONG_LONG +#else +#error "No basic integer type has a size of 32 bits exactly" +#endif + +#if (SHRT_MAX == 9223372036854775807LL) +#define FLAGS_INT64 FLAGS_SHORT +#elif (INT_MAX == 9223372036854775807LL) +#define FLAGS_INT64 FLAGS_INT +#elif (LONG_MAX == 9223372036854775807LL) +#define FLAGS_INT64 FLAGS_LONG +#elif (LLONG_MAX == 9223372036854775807LL) +#define FLAGS_INT64 FLAGS_LONG_LONG +#else +#error "No basic integer type has a size of 64 bits exactly" +#endif + +#endif // PRINTF_SUPPORT_MSVC_STYLE_INTEGER_SPECIFIERS + + +typedef unsigned int printf_flags_t; + +#define BASE_BINARY 2 +#define BASE_OCTAL 8 +#define BASE_DECIMAL 10 +#define BASE_HEX 16 + +typedef uint8_t numeric_base_t; + +#if PRINTF_SUPPORT_LONG_LONG +typedef unsigned long long printf_unsigned_value_t; +typedef long long printf_signed_value_t; +#else +typedef unsigned long printf_unsigned_value_t; +typedef long printf_signed_value_t; +#endif + +// The printf()-family functions return an `int`; it is therefore +// unnecessary/inappropriate to use size_t - often larger than int +// in practice - for non-negative related values, such as widths, +// precisions, offsets into buffers used for printing and the sizes +// of these buffers. instead, we use: +typedef unsigned int printf_size_t; +#define PRINTF_MAX_POSSIBLE_BUFFER_SIZE INT_MAX + // If we were to nitpick, this would actually be INT_MAX + 1, + // since INT_MAX is the maximum return value, which excludes the + // trailing '\0'. + +#if (PRINTF_SUPPORT_DECIMAL_SPECIFIERS || PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS) +#include +#if FLT_RADIX != 2 +#error "Non-binary-radix floating-point types are unsupported." +#endif + +/** + * This library supports taking float-point arguments up to and including + * long double's; but - it currently does _not_ support internal + * representation and manipulation of values as long doubles; the options + * are either single-precision `float` or double-precision `double`. + */ +#if PRINTF_USE_DOUBLE_INTERNALLY +typedef double floating_point_t; +#define FP_TYPE_MANT_DIG DBL_MANT_DIG +#else +typedef float floating_point_t; +#define FP_TYPE_MANT_DIG FLT_MANT_DIG +#endif + +#define NUM_DECIMAL_DIGITS_IN_INT64_T 18 + +#if FP_TYPE_MANT_DIG == 24 + +typedef uint32_t printf_fp_uint_t; +#define FP_TYPE_SIZE_IN_BITS 32 +#define FP_TYPE_EXPONENT_MASK 0xFFU +#define FP_TYPE_BASE_EXPONENT 127 +#define FP_TYPE_MAX FLT_MAX +#define FP_TYPE_MAX_10_EXP FLT_MAX_10_EXP +#define FP_TYPE_MAX_SUBNORMAL_EXPONENT_OF_10 -38 +#define FP_TYPE_MAX_SUBNORMAL_POWER_OF_10 1e-38f +#define PRINTF_MAX_PRECOMPUTED_POWER_OF_10 10 + +#elif FP_TYPE_MANT_DIG == 53 + +typedef uint64_t printf_fp_uint_t; +#define FP_TYPE_SIZE_IN_BITS 64 +#define FP_TYPE_EXPONENT_MASK 0x7FFU +#define FP_TYPE_BASE_EXPONENT 1023 +#define FP_TYPE_MAX DBL_MAX +#define FP_TYPE_MAX_10_EXP DBL_MAX_10_EXP +#define FP_TYPE_MAX_10_EXP DBL_MAX_10_EXP +#define FP_TYPE_MAX_SUBNORMAL_EXPONENT_OF_10 -308 +#define FP_TYPE_MAX_SUBNORMAL_POWER_OF_10 1e-308 +#define PRINTF_MAX_PRECOMPUTED_POWER_OF_10 NUM_DECIMAL_DIGITS_IN_INT64_T - 1 + + +#else +#error "Unsupported floating point type configuration" +#endif +#define FP_TYPE_STORED_MANTISSA_BITS (FP_TYPE_MANT_DIG - 1) + +typedef union { + printf_fp_uint_t U; + floating_point_t F; +} floating_point_with_bit_access; + +// This is unnecessary in C99, since compound initializers can be used, +// but: +// 1. Some compilers are finicky about this; +// 2. Some people may want to convert this to C89; +// 3. If you try to use it as C++, only C++20 supports compound literals +static inline floating_point_with_bit_access get_bit_access(floating_point_t x) +{ + floating_point_with_bit_access dwba; + dwba.F = x; + return dwba; +} + +static inline int get_sign_bit(floating_point_t x) +{ + // The sign is stored in the highest bit + return (int) (get_bit_access(x).U >> (FP_TYPE_SIZE_IN_BITS - 1)); +} + +static inline int get_exp2(floating_point_with_bit_access x) +{ + // The exponent in an IEEE-754 floating-point number occupies a contiguous + // sequence of bits (e.g. 52..62 for 64-bit doubles), but with a non-trivial representation: An + // unsigned offset from some negative value (with the extremal offset values reserved for + // special use). + return (int)((x.U >> FP_TYPE_STORED_MANTISSA_BITS ) & FP_TYPE_EXPONENT_MASK) - FP_TYPE_BASE_EXPONENT; +} +#define PRINTF_ABS(_x) ( (_x) > 0 ? (_x) : -(_x) ) + +#endif // (PRINTF_SUPPORT_DECIMAL_SPECIFIERS || PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS) + +// Note in particular the behavior here on LONG_MIN or LLONG_MIN; it is valid +// and well-defined, but if you're not careful you can easily trigger undefined +// behavior with -LONG_MIN or -LLONG_MIN +#define ABS_FOR_PRINTING(_x) ((printf_unsigned_value_t) ( (_x) > 0 ? (_x) : -((printf_signed_value_t)_x) )) + +// wrapper (used as buffer) for output function type +// +// One of the following must hold: +// 1. max_chars is 0 +// 2. buffer is non-null +// 3. function is non-null +// +// ... otherwise bad things will happen. +typedef struct { + void (*function)(char c, void* extra_arg); + void* extra_function_arg; + char* buffer; + printf_size_t pos; + printf_size_t max_chars; +} output_gadget_t; + +// Note: This function currently assumes it is not passed a '\0' c, +// or alternatively, that '\0' can be passed to the function in the output +// gadget. The former assumption holds within the printf library. It also +// assumes that the output gadget has been properly initialized. +static inline void putchar_via_gadget(output_gadget_t* gadget, char c) +{ + printf_size_t write_pos = gadget->pos++; + // We're _always_ increasing pos, so as to count how may characters + // _would_ have been written if not for the max_chars limitation + if (write_pos >= gadget->max_chars) { + return; + } + if (gadget->function != NULL) { + // No check for c == '\0' . + gadget->function(c, gadget->extra_function_arg); + } + else { + // it must be the case that gadget->buffer != NULL , due to the constraint + // on output_gadget_t ; and note we're relying on write_pos being non-negative. + gadget->buffer[write_pos] = c; + } +} + +// Possibly-write the string-terminating '\0' character +static inline void append_termination_with_gadget(output_gadget_t* gadget) +{ + if (gadget->function != NULL || gadget->max_chars == 0) { + return; + } + if (gadget->buffer == NULL) { + return; + } + printf_size_t null_char_pos = gadget->pos < gadget->max_chars ? gadget->pos : gadget->max_chars - 1; + gadget->buffer[null_char_pos] = '\0'; +} + +// We can't use putchar_ as is, since our output gadget +// only takes pointers to functions with an extra argument +static inline void putchar_wrapper(char c, void* unused) +{ + (void) unused; + putchar_(c); +} + +static inline output_gadget_t discarding_gadget(void) +{ + output_gadget_t gadget; + gadget.function = NULL; + gadget.extra_function_arg = NULL; + gadget.buffer = NULL; + gadget.pos = 0; + gadget.max_chars = 0; + return gadget; +} + +static inline output_gadget_t buffer_gadget(char* buffer, size_t buffer_size) +{ + printf_size_t usable_buffer_size = (buffer_size > PRINTF_MAX_POSSIBLE_BUFFER_SIZE) ? + PRINTF_MAX_POSSIBLE_BUFFER_SIZE : (printf_size_t) buffer_size; + output_gadget_t result = discarding_gadget(); + if (buffer != NULL) { + result.buffer = buffer; + result.max_chars = usable_buffer_size; + } + return result; +} + +static inline output_gadget_t function_gadget(void (*function)(char, void*), void* extra_arg) +{ + output_gadget_t result = discarding_gadget(); + result.function = function; + result.extra_function_arg = extra_arg; + result.max_chars = PRINTF_MAX_POSSIBLE_BUFFER_SIZE; + return result; +} + +static inline output_gadget_t extern_putchar_gadget(void) +{ + return function_gadget(putchar_wrapper, NULL); +} + +// internal secure strlen +// @return The length of the string (excluding the terminating 0) limited by 'maxsize' +// @note strlen uses size_t, but wes only use this function with printf_size_t +// variables - hence the signature. +static inline printf_size_t strnlen_s_(const char* str, printf_size_t maxsize) +{ + const char* s; + for (s = str; *s && maxsize--; ++s); + return (printf_size_t)(s - str); +} + + +// internal test if char is a digit (0-9) +// @return true if char is a digit +static inline bool is_digit_(char ch) +{ + return (ch >= '0') && (ch <= '9'); +} + + +// internal ASCII string to printf_size_t conversion +static printf_size_t atou_(const char** str) +{ + printf_size_t i = 0U; + while (is_digit_(**str)) { + i = i * 10U + (printf_size_t)(*((*str)++) - '0'); + } + return i; +} + + +// output the specified string in reverse, taking care of any zero-padding +static void out_rev_(output_gadget_t* output, const char* buf, printf_size_t len, printf_size_t width, printf_flags_t flags) +{ + const printf_size_t start_pos = output->pos; + + // pad spaces up to given width + if (!(flags & FLAGS_LEFT) && !(flags & FLAGS_ZEROPAD)) { + for (printf_size_t i = len; i < width; i++) { + putchar_via_gadget(output, ' '); + } + } + + // reverse string + while (len) { + putchar_via_gadget(output, buf[--len]); + } + + // append pad spaces up to given width + if (flags & FLAGS_LEFT) { + while (output->pos - start_pos < width) { + putchar_via_gadget(output, ' '); + } + } +} + + +// Invoked by print_integer after the actual number has been printed, performing necessary +// work on the number's prefix (as the number is initially printed in reverse order) +static void print_integer_finalization(output_gadget_t* output, char* buf, printf_size_t len, bool negative, numeric_base_t base, printf_size_t precision, printf_size_t width, printf_flags_t flags) +{ + printf_size_t unpadded_len = len; + + // pad with leading zeros + { + if (!(flags & FLAGS_LEFT)) { + if (width && (flags & FLAGS_ZEROPAD) && (negative || (flags & (FLAGS_PLUS | FLAGS_SPACE)))) { + width--; + } + while ((flags & FLAGS_ZEROPAD) && (len < width) && (len < PRINTF_INTEGER_BUFFER_SIZE)) { + buf[len++] = '0'; + } + } + + while ((len < precision) && (len < PRINTF_INTEGER_BUFFER_SIZE)) { + buf[len++] = '0'; + } + + if (base == BASE_OCTAL && (len > unpadded_len)) { + // Since we've written some zeros, we've satisfied the alternative format leading space requirement + flags &= ~FLAGS_HASH; + } + } + + // handle hash + if (flags & (FLAGS_HASH | FLAGS_POINTER)) { + if (!(flags & FLAGS_PRECISION) && len && ((len == precision) || (len == width))) { + // Let's take back some padding digits to fit in what will eventually + // be the format-specific prefix + if (unpadded_len < len) { + len--; // This should suffice for BASE_OCTAL + } + if (len && (base == BASE_HEX || base == BASE_BINARY) && (unpadded_len < len)) { + len--; // ... and an extra one for 0x or 0b + } + } + if ((base == BASE_HEX) && !(flags & FLAGS_UPPERCASE) && (len < PRINTF_INTEGER_BUFFER_SIZE)) { + buf[len++] = 'x'; + } + else if ((base == BASE_HEX) && (flags & FLAGS_UPPERCASE) && (len < PRINTF_INTEGER_BUFFER_SIZE)) { + buf[len++] = 'X'; + } + else if ((base == BASE_BINARY) && (len < PRINTF_INTEGER_BUFFER_SIZE)) { + buf[len++] = 'b'; + } + if (len < PRINTF_INTEGER_BUFFER_SIZE) { + buf[len++] = '0'; + } + } + + if (len < PRINTF_INTEGER_BUFFER_SIZE) { + if (negative) { + buf[len++] = '-'; + } + else if (flags & FLAGS_PLUS) { + buf[len++] = '+'; // ignore the space if the '+' exists + } + else if (flags & FLAGS_SPACE) { + buf[len++] = ' '; + } + } + + out_rev_(output, buf, len, width, flags); +} + +// An internal itoa-like function +static void print_integer(output_gadget_t* output, printf_unsigned_value_t value, bool negative, numeric_base_t base, printf_size_t precision, printf_size_t width, printf_flags_t flags) +{ + char buf[PRINTF_INTEGER_BUFFER_SIZE]; + printf_size_t len = 0U; + + if (!value) { + if ( !(flags & FLAGS_PRECISION) ) { + buf[len++] = '0'; + flags &= ~FLAGS_HASH; + // We drop this flag this since either the alternative and regular modes of the specifier + // don't differ on 0 values, or (in the case of octal) we've already provided the special + // handling for this mode. + } + else if (base == BASE_HEX) { + flags &= ~FLAGS_HASH; + // We drop this flag this since either the alternative and regular modes of the specifier + // don't differ on 0 values + } + } + else { + do { + const char digit = (char)(value % base); + buf[len++] = (char)(digit < 10 ? '0' + digit : (flags & FLAGS_UPPERCASE ? 'A' : 'a') + digit - 10); + value /= base; + } while (value && (len < PRINTF_INTEGER_BUFFER_SIZE)); + } + + print_integer_finalization(output, buf, len, negative, base, precision, width, flags); +} + +#if (PRINTF_SUPPORT_DECIMAL_SPECIFIERS || PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS) + +// Stores a fixed-precision representation of a floating-point number relative +// to a fixed precision (which cannot be determined by examining this structure) +struct floating_point_components { + int_fast64_t integral; + int_fast64_t fractional; + // ... truncation of the actual fractional part of the floating_point_t value, scaled + // by the precision value + bool is_negative; +}; + +static const floating_point_t powers_of_10[PRINTF_MAX_PRECOMPUTED_POWER_OF_10 + 1] = { + 1e00, 1e01, 1e02, 1e03, 1e04, 1e05, 1e06, 1e07, 1e08, 1e09, 1e10 +#if PRINTF_MAX_PRECOMPUTED_POWER_OF_10 > 10 + , 1e11, 1e12, 1e13, 1e14, 1e15, 1e16, 1e17 +#endif +}; + +// Note: This value does not mean that all floating-point values printed with the +// library will be correct up to this precision; it is just an upper-bound for +// avoiding buffer overruns and such +#define PRINTF_MAX_SUPPORTED_PRECISION (NUM_DECIMAL_DIGITS_IN_INT64_T - 1) + + +// Break up a floating-point number - which is known to be a finite non-negative number - +// into its base-10 parts: integral - before the decimal point, and fractional - after it. +// Taken the precision into account, but does not change it even internally. +static struct floating_point_components get_components(floating_point_t number, printf_size_t precision) +{ + struct floating_point_components number_; + number_.is_negative = get_sign_bit(number); + floating_point_t abs_number = (number_.is_negative) ? -number : number; + number_.integral = (int_fast64_t) abs_number; + floating_point_t scaled_remainder = (abs_number - (floating_point_t) number_.integral) * powers_of_10[precision]; + number_.fractional = (int_fast64_t) scaled_remainder; // for precision == 0U, this will be 0 + + floating_point_t remainder = scaled_remainder - (floating_point_t) number_.fractional; + const floating_point_t one_half = (floating_point_t) 0.5; + + if (remainder > one_half) { + ++number_.fractional; + // handle rollover, e.g. case 0.99 with precision 1 is 1.0 + if ((floating_point_t) number_.fractional >= powers_of_10[precision]) { + number_.fractional = 0; + ++number_.integral; + } + } + else if ((remainder == one_half) && (number_.fractional & 1U)) { + // Banker's rounding, i.e. round half to even: + // 1.5 -> 2, but 2.5 -> 2 + ++number_.fractional; + } + + if (precision == 0U) { + remainder = abs_number - (floating_point_t) number_.integral; + if ((remainder == one_half) && (number_.integral & 1U)) { + // Banker's rounding, i.e. round half to even: + // 1.5 -> 2, but 2.5 -> 2 + ++number_.integral; + } + } + return number_; +} + +#if PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS +struct scaling_factor { + floating_point_t raw_factor; + bool multiply; // if true, need to multiply by raw_factor; otherwise need to divide by it +}; + +static floating_point_t apply_scaling(floating_point_t num, struct scaling_factor normalization) +{ + return normalization.multiply ? num * normalization.raw_factor : num / normalization.raw_factor; +} + +static floating_point_t unapply_scaling(floating_point_t normalized, struct scaling_factor normalization) +{ +#ifdef __GNUC__ +// accounting for a static analysis bug in GCC 6.x and earlier +#pragma GCC diagnostic push +#if !defined(__has_warning) +#pragma GCC diagnostic ignored "-Wmaybe-uninitialized" +#elif __has_warning("-Wmaybe-uninitialized") +#pragma GCC diagnostic ignored "-Wmaybe-uninitialized" +#endif +#endif + return normalization.multiply ? normalized / normalization.raw_factor : normalized * normalization.raw_factor; +#ifdef __GNUC__ +#pragma GCC diagnostic pop +#endif +} + +static struct scaling_factor update_normalization(struct scaling_factor sf, floating_point_t extra_multiplicative_factor) +{ + struct scaling_factor result; + if (sf.multiply) { + result.multiply = true; + result.raw_factor = sf.raw_factor * extra_multiplicative_factor; + } + else { + int factor_exp2 = get_exp2(get_bit_access(sf.raw_factor)); + int extra_factor_exp2 = get_exp2(get_bit_access(extra_multiplicative_factor)); + + // Divide the larger-exponent raw raw_factor by the smaller + if (PRINTF_ABS(factor_exp2) > PRINTF_ABS(extra_factor_exp2)) { + result.multiply = false; + result.raw_factor = sf.raw_factor / extra_multiplicative_factor; + } + else { + result.multiply = true; + result.raw_factor = extra_multiplicative_factor / sf.raw_factor; + } + } + return result; +} + +static struct floating_point_components get_normalized_components(bool negative, printf_size_t precision, floating_point_t non_normalized, struct scaling_factor normalization, int floored_exp10) +{ + struct floating_point_components components; + components.is_negative = negative; + floating_point_t scaled = apply_scaling(non_normalized, normalization); + + bool close_to_representation_extremum = ( (-floored_exp10 + (int) precision) >= FP_TYPE_MAX_10_EXP - 1 ); + if (close_to_representation_extremum) { + // We can't have a normalization factor which also accounts for the precision, i.e. moves + // some decimal digits into the mantissa, since it's unrepresentable, or nearly unrepresentable. + // So, we'll give up early on getting extra precision... + return get_components(negative ? -scaled : scaled, precision); + } + components.integral = (int_fast64_t) scaled; + floating_point_t remainder = non_normalized - unapply_scaling((floating_point_t) components.integral, normalization); + floating_point_t prec_power_of_10 = powers_of_10[precision]; + struct scaling_factor account_for_precision = update_normalization(normalization, prec_power_of_10); + floating_point_t scaled_remainder = apply_scaling(remainder, account_for_precision); + floating_point_t rounding_threshold = 0.5; + + components.fractional = (int_fast64_t) scaled_remainder; // when precision == 0, the assigned value should be 0 + scaled_remainder -= (floating_point_t) components.fractional; //when precision == 0, this will not change scaled_remainder + + components.fractional += (scaled_remainder >= rounding_threshold); + if (scaled_remainder == rounding_threshold) { + // banker's rounding: Round towards the even number (making the mean error 0) + components.fractional &= ~((int_fast64_t) 0x1); + } + // handle rollover, e.g. the case of 0.99 with precision 1 becoming (0,100), + // and must then be corrected into (1, 0). + // Note: for precision = 0, this will "translate" the rounding effect from + // the fractional part to the integral part where it should actually be + // felt (as prec_power_of_10 is 1) + if ((floating_point_t) components.fractional >= prec_power_of_10) { + components.fractional = 0; + ++components.integral; + } + return components; +} +#endif // PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS + +static void print_broken_up_decimal( + struct floating_point_components number_, output_gadget_t* output, printf_size_t precision, + printf_size_t width, printf_flags_t flags, char *buf, printf_size_t len) +{ + if (precision != 0U) { + // do fractional part, as an unsigned number + + printf_size_t count = precision; + + // %g/%G mandates we skip the trailing 0 digits... + if ((flags & FLAGS_ADAPT_EXP) && !(flags & FLAGS_HASH) && (number_.fractional > 0)) { + while(true) { + int_fast64_t digit = number_.fractional % 10U; + if (digit != 0) { + break; + } + --count; + number_.fractional /= 10U; + + } + // ... and even the decimal point if there are no + // non-zero fractional part digits (see below) + } + + if (number_.fractional > 0 || !(flags & FLAGS_ADAPT_EXP) || (flags & FLAGS_HASH) ) { + while (len < PRINTF_DECIMAL_BUFFER_SIZE) { + --count; + buf[len++] = (char)('0' + number_.fractional % 10U); + if (!(number_.fractional /= 10U)) { + break; + } + } + // add extra 0s + while ((len < PRINTF_DECIMAL_BUFFER_SIZE) && (count > 0U)) { + buf[len++] = '0'; + --count; + } + if (len < PRINTF_DECIMAL_BUFFER_SIZE) { + buf[len++] = '.'; + } + } + } + else { + if ((flags & FLAGS_HASH) && (len < PRINTF_DECIMAL_BUFFER_SIZE)) { + buf[len++] = '.'; + } + } + + // Write the integer part of the number (it comes after the fractional + // since the character order is reversed) + while (len < PRINTF_DECIMAL_BUFFER_SIZE) { + buf[len++] = (char)('0' + (number_.integral % 10)); + if (!(number_.integral /= 10)) { + break; + } + } + + // pad leading zeros + if (!(flags & FLAGS_LEFT) && (flags & FLAGS_ZEROPAD)) { + if (width && (number_.is_negative || (flags & (FLAGS_PLUS | FLAGS_SPACE)))) { + width--; + } + while ((len < width) && (len < PRINTF_DECIMAL_BUFFER_SIZE)) { + buf[len++] = '0'; + } + } + + if (len < PRINTF_DECIMAL_BUFFER_SIZE) { + if (number_.is_negative) { + buf[len++] = '-'; + } + else if (flags & FLAGS_PLUS) { + buf[len++] = '+'; // ignore the space if the '+' exists + } + else if (flags & FLAGS_SPACE) { + buf[len++] = ' '; + } + } + + out_rev_(output, buf, len, width, flags); +} + +// internal ftoa for fixed decimal floating point +static void print_decimal_number(output_gadget_t* output, floating_point_t number, printf_size_t precision, printf_size_t width, printf_flags_t flags, char* buf, printf_size_t len) +{ + struct floating_point_components value_ = get_components(number, precision); + print_broken_up_decimal(value_, output, precision, width, flags, buf, len); +} + +#if PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS + +// A floor function - but one which only works for numbers whose +// floor value is representable by an int. +static int bastardized_floor(floating_point_t x) +{ + if (x >= 0) { return (int) x; } + int n = (int) x; + return ( ((floating_point_t) n) == x ) ? n : n-1; +} + +// Computes the base-10 logarithm of the input number - which must be an actual +// positive number (not infinity or NaN, nor a sub-normal) +static floating_point_t log10_of_positive(floating_point_t positive_number) +{ + // The implementation follows David Gay (https://www.ampl.com/netlib/fp/dtoa.c). + // + // Since log_10 ( M * 2^x ) = log_10(M) + x , we can separate the components of + // our input number, and need only solve log_10(M) for M between 1 and 2 (as + // the base-2 mantissa is always 1-point-something). In that limited range, a + // Taylor series expansion of log10(x) should serve us well enough; and we'll + // take the mid-point, 1.5, as the point of expansion. + + floating_point_with_bit_access dwba = get_bit_access(positive_number); + // based on the algorithm by David Gay (https://www.ampl.com/netlib/fp/dtoa.c) + int exp2 = get_exp2(dwba); + // drop the exponent, so dwba.F comes into the range [1,2) + dwba.U = (dwba.U & (((printf_fp_uint_t) (1) << FP_TYPE_STORED_MANTISSA_BITS) - 1U)) | + ((printf_fp_uint_t) FP_TYPE_BASE_EXPONENT << FP_TYPE_STORED_MANTISSA_BITS); + floating_point_t z = (dwba.F - (floating_point_t) 1.5); + return ( + // Taylor expansion around 1.5: + (floating_point_t) 0.1760912590556812420 // Expansion term 0: ln(1.5) / ln(10) + + z * (floating_point_t) 0.2895296546021678851 // Expansion term 1: (M - 1.5) * 2/3 / ln(10) +#if PRINTF_LOG10_TAYLOR_TERMS > 2 + - z*z * (floating_point_t) 0.0965098848673892950 // Expansion term 2: (M - 1.5)^2 * 2/9 / ln(10) +#if PRINTF_LOG10_TAYLOR_TERMS > 3 + + z*z*z * (floating_point_t) 0.0428932821632841311 // Expansion term 2: (M - 1.5)^3 * 8/81 / ln(10) +#endif +#endif + // exact log_2 of the exponent x, with logarithm base change + + (floating_point_t) exp2 * (floating_point_t) 0.30102999566398119521 // = exp2 * log_10(2) = exp2 * ln(2)/ln(10) + ); +} + + +static floating_point_t pow10_of_int(int floored_exp10) +{ + // A crude hack for avoiding undesired behavior with barely-normal or slightly-subnormal values. + if (floored_exp10 == FP_TYPE_MAX_SUBNORMAL_EXPONENT_OF_10) { + return FP_TYPE_MAX_SUBNORMAL_POWER_OF_10; + } + // Compute 10^(floored_exp10) but (try to) make sure that doesn't overflow + floating_point_with_bit_access dwba; + int exp2 = bastardized_floor((floating_point_t) (floored_exp10 * 3.321928094887362 + 0.5)); + const floating_point_t z = (floating_point_t) (floored_exp10 * 2.302585092994046 - exp2 * 0.6931471805599453); + const floating_point_t z2 = z * z; + dwba.U = ((printf_fp_uint_t)(exp2) + FP_TYPE_BASE_EXPONENT) << FP_TYPE_STORED_MANTISSA_BITS; + // compute exp(z) using continued fractions, + // see https://en.wikipedia.org/wiki/Exponential_function#Continued_fractions_for_ex + dwba.F *= 1 + 2 * z / (2 - z + (z2 / (6 + (z2 / (10 + z2 / 14))))); + return dwba.F; +} + +static void print_exponential_number(output_gadget_t* output, floating_point_t number, printf_size_t precision, printf_size_t width, printf_flags_t flags, char* buf, printf_size_t len) +{ + const bool negative = get_sign_bit(number); + // This number will decrease gradually (by factors of 10) as we "extract" the exponent out of it + floating_point_t abs_number = negative ? -number : number; + + int floored_exp10; + bool abs_exp10_covered_by_powers_table; + struct scaling_factor normalization; + + + // Determine the decimal exponent + if (abs_number == (floating_point_t) 0.0) { + // TODO: This is a special-case for 0.0 (and -0.0); but proper handling is required for denormals more generally. + floored_exp10 = 0; // ... and no need to set a normalization factor or check the powers table + } + else { + floating_point_t exp10 = log10_of_positive(abs_number); + floored_exp10 = bastardized_floor(exp10); + floating_point_t p10 = pow10_of_int(floored_exp10); + // correct for rounding errors + if (abs_number < p10) { + floored_exp10--; + p10 /= 10; + } + abs_exp10_covered_by_powers_table = PRINTF_ABS(floored_exp10) < PRINTF_MAX_PRECOMPUTED_POWER_OF_10; + normalization.raw_factor = abs_exp10_covered_by_powers_table ? powers_of_10[PRINTF_ABS(floored_exp10)] : p10; + } + + // We now begin accounting for the widths of the two parts of our printed field: + // the decimal part after decimal exponent extraction, and the base-10 exponent part. + // For both of these, the value of 0 has a special meaning, but not the same one: + // a 0 exponent-part width means "don't print the exponent"; a 0 decimal-part width + // means "use as many characters as necessary". + + bool fall_back_to_decimal_only_mode = false; + if (flags & FLAGS_ADAPT_EXP) { + int required_significant_digits = (precision == 0) ? 1 : (int) precision; + // Should we want to fall-back to "%f" mode, and only print the decimal part? + fall_back_to_decimal_only_mode = (floored_exp10 >= -4 && floored_exp10 < required_significant_digits); + // Now, let's adjust the precision + // This also decided how we adjust the precision value - as in "%g" mode, + // "precision" is the number of _significant digits_, and this is when we "translate" + // the precision value to an actual number of decimal digits. + int precision_ = fall_back_to_decimal_only_mode ? + (int) precision - 1 - floored_exp10 : + (int) precision - 1; // the presence of the exponent ensures only one significant digit comes before the decimal point + precision = (precision_ > 0 ? (unsigned) precision_ : 0U); + flags |= FLAGS_PRECISION; // make sure print_broken_up_decimal respects our choice above + } + +#ifdef __GNUC__ +// accounting for a static analysis bug in GCC 6.x and earlier +#pragma GCC diagnostic push +#if !defined(__has_warning) +#pragma GCC diagnostic ignored "-Wmaybe-uninitialized" +#elif __has_warning("-Wmaybe-uninitialized") +#pragma GCC diagnostic ignored "-Wmaybe-uninitialized" +#endif +#endif + normalization.multiply = (floored_exp10 < 0 && abs_exp10_covered_by_powers_table); +#ifdef __GNUC__ +#pragma GCC diagnostic pop +#endif + bool should_skip_normalization = (fall_back_to_decimal_only_mode || floored_exp10 == 0); + struct floating_point_components decimal_part_components = + should_skip_normalization ? + get_components(negative ? -abs_number : abs_number, precision) : + get_normalized_components(negative, precision, abs_number, normalization, floored_exp10); + + // Account for roll-over, e.g. rounding from 9.99 to 100.0 - which effects + // the exponent and may require additional tweaking of the parts + if (fall_back_to_decimal_only_mode) { + if ((flags & FLAGS_ADAPT_EXP) && floored_exp10 >= -1 && decimal_part_components.integral == powers_of_10[floored_exp10 + 1]) { + floored_exp10++; // Not strictly necessary, since floored_exp10 is no longer really used + if (precision > 0U) { precision--; } + // ... and it should already be the case that decimal_part_components.fractional == 0 + } + // TODO: What about rollover strictly within the fractional part? + } + else { + if (decimal_part_components.integral >= 10) { + floored_exp10++; + decimal_part_components.integral = 1; + decimal_part_components.fractional = 0; + } + } + + // the floored_exp10 format is "E%+03d" and largest possible floored_exp10 value for a 64-bit double + // is "307" (for 2^1023), so we set aside 4-5 characters overall + printf_size_t exp10_part_width = fall_back_to_decimal_only_mode ? 0U : (PRINTF_ABS(floored_exp10) < 100) ? 4U : 5U; + + printf_size_t decimal_part_width = + ((flags & FLAGS_LEFT) && exp10_part_width) ? + // We're padding on the right, so the width constraint is the exponent part's + // problem, not the decimal part's, so we'll use as many characters as we need: + 0U : + // We're padding on the left; so the width constraint is the decimal part's + // problem. Well, can both the decimal part and the exponent part fit within our overall width? + ((width > exp10_part_width) ? + // Yes, so we limit our decimal part's width. + // (Note this is trivially valid even if we've fallen back to "%f" mode) + width - exp10_part_width : + // No; we just give up on any restriction on the decimal part and use as many + // characters as we need + 0U); + + const printf_size_t printed_exponential_start_pos = output->pos; + print_broken_up_decimal(decimal_part_components, output, precision, decimal_part_width, flags, buf, len); + + if (! fall_back_to_decimal_only_mode) { + putchar_via_gadget(output, (flags & FLAGS_UPPERCASE) ? 'E' : 'e'); + print_integer(output, + ABS_FOR_PRINTING(floored_exp10), + floored_exp10 < 0, 10, 0, exp10_part_width - 1, + FLAGS_ZEROPAD | FLAGS_PLUS); + if (flags & FLAGS_LEFT) { + // We need to right-pad with spaces to meet the width requirement + while (output->pos - printed_exponential_start_pos < width) { + putchar_via_gadget(output, ' '); + } + } + } +} +#endif // PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS + +static void print_floating_point(output_gadget_t* output, floating_point_t value, printf_size_t precision, printf_size_t width, printf_flags_t flags, bool prefer_exponential) +{ + char buf[PRINTF_DECIMAL_BUFFER_SIZE]; + printf_size_t len = 0U; + + // test for special values + if (value != value) { + out_rev_(output, "nan", 3, width, flags); + return; + } + if (value < -FP_TYPE_MAX) { + out_rev_(output, "fni-", 4, width, flags); + return; + } + if (value > FP_TYPE_MAX) { + out_rev_(output, (flags & FLAGS_PLUS) ? "fni+" : "fni", (flags & FLAGS_PLUS) ? 4U : 3U, width, flags); + return; + } + + if (!prefer_exponential && + ((value > PRINTF_FLOAT_NOTATION_THRESHOLD) || (value < -PRINTF_FLOAT_NOTATION_THRESHOLD))) { + // The required behavior of standard printf is to print _every_ integral-part digit -- which could mean + // printing hundreds of characters, overflowing any fixed internal buffer and necessitating a more complicated + // implementation. +#if PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS + print_exponential_number(output, value, precision, width, flags, buf, len); +#endif + return; + } + + // set default precision, if not set explicitly + if (!(flags & FLAGS_PRECISION)) { + precision = PRINTF_DEFAULT_FLOAT_PRECISION; + } + + // limit precision so that our integer holding the fractional part does not overflow + while ((len < PRINTF_DECIMAL_BUFFER_SIZE) && (precision > PRINTF_MAX_SUPPORTED_PRECISION)) { + buf[len++] = '0'; // This respects the precision in terms of result length only + precision--; + } + +#if PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS + if (prefer_exponential) + print_exponential_number(output, value, precision, width, flags, buf, len); + else +#endif + print_decimal_number(output, value, precision, width, flags, buf, len); +} + +#endif // (PRINTF_SUPPORT_DECIMAL_SPECIFIERS || PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS) + +// Advances the format pointer past the flags, and returns the parsed flags +// due to the characters passed +static printf_flags_t parse_flags(const char** format) +{ + printf_flags_t flags = 0U; + do { + switch (**format) { + case '0': flags |= FLAGS_ZEROPAD; (*format)++; break; + case '-': flags |= FLAGS_LEFT; (*format)++; break; + case '+': flags |= FLAGS_PLUS; (*format)++; break; + case ' ': flags |= FLAGS_SPACE; (*format)++; break; + case '#': flags |= FLAGS_HASH; (*format)++; break; + default : return flags; + } + } while (true); +} + +static inline void format_string_loop(output_gadget_t* output, const char* format, va_list args) +{ +#if PRINTF_CHECK_FOR_NUL_IN_FORMAT_SPECIFIER +#define ADVANCE_IN_FORMAT_STRING(cptr_) do { (cptr_)++; if (!*(cptr_)) return; } while(0) +#else +#define ADVANCE_IN_FORMAT_STRING(cptr_) (cptr_)++ +#endif + + + while (*format) + { + if (*format != '%') { + // A regular content character + putchar_via_gadget(output, *format); + format++; + continue; + } + // We're parsing a format specifier: %[flags][width][.precision][length] + ADVANCE_IN_FORMAT_STRING(format); + + printf_flags_t flags = parse_flags(&format); + + // evaluate width field + printf_size_t width = 0U; + if (is_digit_(*format)) { + width = (printf_size_t) atou_(&format); + } + else if (*format == '*') { + const int w = va_arg(args, int); + if (w < 0) { + flags |= FLAGS_LEFT; // reverse padding + width = (printf_size_t)-w; + } + else { + width = (printf_size_t)w; + } + ADVANCE_IN_FORMAT_STRING(format); + } + + // evaluate precision field + printf_size_t precision = 0U; + if (*format == '.') { + flags |= FLAGS_PRECISION; + ADVANCE_IN_FORMAT_STRING(format); + if (is_digit_(*format)) { + precision = (printf_size_t) atou_(&format); + } + else if (*format == '*') { + const int precision_ = va_arg(args, int); + precision = precision_ > 0 ? (printf_size_t) precision_ : 0U; + ADVANCE_IN_FORMAT_STRING(format); + } + } + + // evaluate length field + switch (*format) { +#ifdef PRINTF_SUPPORT_MSVC_STYLE_INTEGER_SPECIFIERS + case 'I' : { + ADVANCE_IN_FORMAT_STRING(format); + // Greedily parse for size in bits: 8, 16, 32 or 64 + switch(*format) { + case '8': flags |= FLAGS_INT8; + ADVANCE_IN_FORMAT_STRING(format); + break; + case '1': + ADVANCE_IN_FORMAT_STRING(format); + if (*format == '6') { format++; flags |= FLAGS_INT16; } + break; + case '3': + ADVANCE_IN_FORMAT_STRING(format); + if (*format == '2') { ADVANCE_IN_FORMAT_STRING(format); flags |= FLAGS_INT32; } + break; + case '6': + ADVANCE_IN_FORMAT_STRING(format); + if (*format == '4') { ADVANCE_IN_FORMAT_STRING(format); flags |= FLAGS_INT64; } + break; + default: break; + } + break; + } +#endif + case 'l' : + flags |= FLAGS_LONG; + ADVANCE_IN_FORMAT_STRING(format); + if (*format == 'l') { + flags |= FLAGS_LONG_LONG; + ADVANCE_IN_FORMAT_STRING(format); + } + break; + case 'L' : + flags |= FLAGS_LONG_DOUBLE; + ADVANCE_IN_FORMAT_STRING(format); + break; + case 'h' : + flags |= FLAGS_SHORT; + ADVANCE_IN_FORMAT_STRING(format); + if (*format == 'h') { + flags |= FLAGS_CHAR; + ADVANCE_IN_FORMAT_STRING(format); + } + break; + case 't' : + flags |= (sizeof(ptrdiff_t) <= sizeof(int) ) ? FLAGS_INT : (sizeof(ptrdiff_t) == sizeof(long)) ? FLAGS_LONG : FLAGS_LONG_LONG; + ADVANCE_IN_FORMAT_STRING(format); + break; + case 'j' : + flags |= (sizeof(intmax_t) == sizeof(long) ? FLAGS_LONG : FLAGS_LONG_LONG); + ADVANCE_IN_FORMAT_STRING(format); + break; + case 'z' : + flags |= (sizeof(size_t) <= sizeof(int) ) ? FLAGS_INT : (sizeof(size_t) == sizeof(long)) ? FLAGS_LONG : FLAGS_LONG_LONG; + ADVANCE_IN_FORMAT_STRING(format); + break; + default: + break; + } + + // evaluate specifier + switch (*format) { + case 'd' : + case 'i' : + case 'u' : + case 'x' : + case 'X' : + case 'o' : + case 'b' : { + + if (*format == 'd' || *format == 'i') { + flags |= FLAGS_SIGNED; + } + + numeric_base_t base; + if (*format == 'x' || *format == 'X') { + base = BASE_HEX; + } + else if (*format == 'o') { + base = BASE_OCTAL; + } + else if (*format == 'b') { + base = BASE_BINARY; + } + else { + base = BASE_DECIMAL; + flags &= ~FLAGS_HASH; // decimal integers have no alternative presentation + } + + if (*format == 'X') { + flags |= FLAGS_UPPERCASE; + } + + format++; + // ignore '0' flag when precision is given + if (flags & FLAGS_PRECISION) { + flags &= ~FLAGS_ZEROPAD; + } + + if (flags & FLAGS_SIGNED) { + // A signed specifier: d, i or possibly I + bit size if enabled + + if (flags & FLAGS_LONG_LONG) { +#if PRINTF_SUPPORT_LONG_LONG + const long long value = va_arg(args, long long); + print_integer(output, ABS_FOR_PRINTING(value), value < 0, base, precision, width, flags); +#endif + } + else if (flags & FLAGS_LONG) { + const long value = va_arg(args, long); + print_integer(output, ABS_FOR_PRINTING(value), value < 0, base, precision, width, flags); + } + else { + // We never try to interpret the argument as something potentially-smaller than int, + // due to integer promotion rules: Even if the user passed a short int, short unsigned + // etc. - these will come in after promotion, as int's (or unsigned for the case of + // short unsigned when it has the same size as int) + const int value = + (flags & FLAGS_CHAR) ? (signed char) va_arg(args, int) : + (flags & FLAGS_SHORT) ? (short int) va_arg(args, int) : + va_arg(args, int); + print_integer(output, ABS_FOR_PRINTING(value), value < 0, base, precision, width, flags); + } + } + else { + // An unsigned specifier: u, x, X, o, b + + flags &= ~(FLAGS_PLUS | FLAGS_SPACE); + + if (flags & FLAGS_LONG_LONG) { +#if PRINTF_SUPPORT_LONG_LONG + print_integer(output, (printf_unsigned_value_t) va_arg(args, unsigned long long), false, base, precision, width, flags); +#endif + } + else if (flags & FLAGS_LONG) { + print_integer(output, (printf_unsigned_value_t) va_arg(args, unsigned long), false, base, precision, width, flags); + } + else { + const unsigned int value = + (flags & FLAGS_CHAR) ? (unsigned char)va_arg(args, unsigned int) : + (flags & FLAGS_SHORT) ? (unsigned short int)va_arg(args, unsigned int) : + va_arg(args, unsigned int); + print_integer(output, (printf_unsigned_value_t) value, false, base, precision, width, flags); + } + } + break; + } +#if PRINTF_SUPPORT_DECIMAL_SPECIFIERS + case 'f' : + case 'F' : { + floating_point_t value = (floating_point_t) (flags & FLAGS_LONG_DOUBLE ? va_arg(args, long double) : va_arg(args, double)); + if (*format == 'F') flags |= FLAGS_UPPERCASE; + print_floating_point(output, value, precision, width, flags, PRINTF_PREFER_DECIMAL); + format++; + break; + } +#endif +#if PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS + case 'e': + case 'E': + case 'g': + case 'G': { + floating_point_t value = (floating_point_t) (flags & FLAGS_LONG_DOUBLE ? va_arg(args, long double) : va_arg(args, double)); + if ((*format == 'g')||(*format == 'G')) flags |= FLAGS_ADAPT_EXP; + if ((*format == 'E')||(*format == 'G')) flags |= FLAGS_UPPERCASE; + print_floating_point(output, value, precision, width, flags, PRINTF_PREFER_EXPONENTIAL); + format++; + break; + } +#endif // PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS + case 'c' : { + printf_size_t l = 1U; + // pre padding + if (!(flags & FLAGS_LEFT)) { + while (l++ < width) { + putchar_via_gadget(output, ' '); + } + } + // char output + putchar_via_gadget(output, (char) va_arg(args, int) ); + // post padding + if (flags & FLAGS_LEFT) { + while (l++ < width) { + putchar_via_gadget(output, ' '); + } + } + format++; + break; + } + + case 's' : { + const char* p = va_arg(args, char*); + if (p == NULL) { + out_rev_(output, ")llun(", 6, width, flags); + } + else { + printf_size_t l = strnlen_s_(p, precision ? precision : PRINTF_MAX_POSSIBLE_BUFFER_SIZE); + // pre padding + if (flags & FLAGS_PRECISION) { + l = (l < precision ? l : precision); + } + if (!(flags & FLAGS_LEFT)) { + while (l++ < width) { + putchar_via_gadget(output, ' '); + } + } + // string output + while ((*p != 0) && (!(flags & FLAGS_PRECISION) || precision)) { + putchar_via_gadget(output, *(p++)); + --precision; + } + // post padding + if (flags & FLAGS_LEFT) { + while (l++ < width) { + putchar_via_gadget(output, ' '); + } + } + } + format++; + break; + } + + case 'p' : { + width = sizeof(void*) * 2U + 2; // 2 hex chars per byte + the "0x" prefix + flags |= FLAGS_ZEROPAD | FLAGS_POINTER; + uintptr_t value = (uintptr_t)va_arg(args, void*); + (value == (uintptr_t) NULL) ? + out_rev_(output, ")lin(", 5, width, flags) : + print_integer(output, (printf_unsigned_value_t) value, false, BASE_HEX, precision, width, flags); + format++; + break; + } + + case '%' : + putchar_via_gadget(output, '%'); + format++; + break; + + // Many people prefer to disable support for %n, as it lets the caller + // engineer a write to an arbitrary location, of a value the caller + // effectively controls - which could be a security concern in some cases. +#if PRINTF_SUPPORT_WRITEBACK_SPECIFIER + case 'n' : { + if (flags & FLAGS_CHAR) *(va_arg(args, char*)) = (char) output->pos; + else if (flags & FLAGS_SHORT) *(va_arg(args, short*)) = (short) output->pos; + else if (flags & FLAGS_LONG) *(va_arg(args, long*)) = (long) output->pos; +#if PRINTF_SUPPORT_LONG_LONG + else if (flags & FLAGS_LONG_LONG) *(va_arg(args, long long*)) = (long long int) output->pos; +#endif // PRINTF_SUPPORT_LONG_LONG + else *(va_arg(args, int*)) = (int) output->pos; + format++; + break; + } +#endif // PRINTF_SUPPORT_WRITEBACK_SPECIFIER + + default : + putchar_via_gadget(output, *format); + format++; + break; + } + } +} + +// internal vsnprintf - used for implementing _all library functions +static int vsnprintf_impl(output_gadget_t* output, const char* format, va_list args) +{ + // Note: The library only calls vsnprintf_impl() with output->pos being 0. However, it is + // possible to call this function with a non-zero pos value for some "remedial printing". + format_string_loop(output, format, args); + + // termination + append_termination_with_gadget(output); + + // return written chars without terminating \0 + return (int)output->pos; +} + +/////////////////////////////////////////////////////////////////////////////// + +int vprintf_(const char* format, va_list arg) +{ + output_gadget_t gadget = extern_putchar_gadget(); + return vsnprintf_impl(&gadget, format, arg); +} + +int vsnprintf_(char* s, size_t n, const char* format, va_list arg) +{ + output_gadget_t gadget = buffer_gadget(s, n); + return vsnprintf_impl(&gadget, format, arg); +} + +int vsprintf_(char* s, const char* format, va_list arg) +{ + return vsnprintf_(s, PRINTF_MAX_POSSIBLE_BUFFER_SIZE, format, arg); +} + +int vfctprintf(void (*out)(char c, void* extra_arg), void* extra_arg, const char* format, va_list arg) +{ + if (out == NULL) { return 0; } + output_gadget_t gadget = function_gadget(out, extra_arg); + return vsnprintf_impl(&gadget, format, arg); +} + +int printf_(const char* format, ...) +{ + va_list args; + va_start(args, format); + const int ret = vprintf_(format, args); + va_end(args); + return ret; +} + +int sprintf_(char* s, const char* format, ...) +{ + va_list args; + va_start(args, format); + const int ret = vsprintf_(s, format, args); + va_end(args); + return ret; +} + +int snprintf_(char* s, size_t n, const char* format, ...) +{ + va_list args; + va_start(args, format); + const int ret = vsnprintf_(s, n, format, args); + va_end(args); + return ret; +} + +int fctprintf(void (*out)(char c, void* extra_arg), void* extra_arg, const char* format, ...) +{ + va_list args; + va_start(args, format); + const int ret = vfctprintf(out, extra_arg, format, args); + va_end(args); + return ret; +} + diff --git a/share/printf/printf.h b/share/printf/printf.h new file mode 100644 index 0000000..48cbade --- /dev/null +++ b/share/printf/printf.h @@ -0,0 +1,236 @@ +/** + * @author (c) Eyal Rozenberg + * 2021-2023, 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 +# include +extern "C" { +#else +# include +# include +#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_SOFT +#define PRINTF_ALIAS_STANDARD_FUNCTION_NAMES_SOFT 0 +#endif + +#ifndef PRINTF_ALIAS_STANDARD_FUNCTION_NAMES_HARD +#define PRINTF_ALIAS_STANDARD_FUNCTION_NAMES_HARD 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 it, 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 + * @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_ diff --git a/share/printf/printf_config.h b/share/printf/printf_config.h new file mode 100644 index 0000000..2979c39 --- /dev/null +++ b/share/printf/printf_config.h @@ -0,0 +1,2 @@ +#define PRINTF_SUPPORT_DECIMAL_SPECIFIERS 0 +#define PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS 0 diff --git a/ulib/Makefile b/ulib/Makefile index a0864d5..bc27d06 100644 --- a/ulib/Makefile +++ b/ulib/Makefile @@ -9,9 +9,11 @@ SRCFILES := $(call GRABSRC, \ syscall \ string \ system \ + printf \ ) -CFLAGS += -isystem $(ROOT)/share -isystem $(ROOT)/ulib -isystem $(ROOT)/std/include +CFLAGS += -isystem $(ROOT)/share -isystem $(ROOT)/ulib -isystem $(ROOT)/std/include \ + -DPRINTF_INCLUDE_CONFIG_H=1 ASFILES := $(call GET_ASFILES, $(SRCFILES)) CFILES := $(call GET_CFILES, $(SRCFILES)) diff --git a/ulib/printf/printf.c b/ulib/printf/printf.c new file mode 120000 index 0000000..eb73a6e --- /dev/null +++ b/ulib/printf/printf.c @@ -0,0 +1 @@ +../../share/printf/printf.c \ No newline at end of file diff --git a/ulib/printf/printf.h b/ulib/printf/printf.h new file mode 120000 index 0000000..051f69c --- /dev/null +++ b/ulib/printf/printf.h @@ -0,0 +1 @@ +../../share/printf/printf.h \ No newline at end of file diff --git a/ulib/printf/printf_config.h b/ulib/printf/printf_config.h new file mode 120000 index 0000000..a64d127 --- /dev/null +++ b/ulib/printf/printf_config.h @@ -0,0 +1 @@ +../../share/printf/printf_config.h \ No newline at end of file diff --git a/ulib/putchar.c b/ulib/putchar.c new file mode 100644 index 0000000..0fef985 --- /dev/null +++ b/ulib/putchar.c @@ -0,0 +1,9 @@ +#include +#include +#include +#include + +void putchar_(char c) { + char buf = c; + ipcpipe(IPCPIPE_SELFPID, IPCPIPE_OUT, IPCPIPE_WRITE, (uint8_t *)&buf, sizeof(buf)); +} diff --git a/ulib/uprintf.h b/ulib/uprintf.h new file mode 100644 index 0000000..d183108 --- /dev/null +++ b/ulib/uprintf.h @@ -0,0 +1,13 @@ +#ifndef ULIB_UPRINTF_H_ +#define ULIB_UPRINTF_H_ + +#include + +#define uprintf printf_ +#define usprintf sprintf_ +#define uvsprintf vsprintf_ +#define usnprintf snprintf_ +#define uvsnprintf vsnprintf_ +#define uvprintf vprintf_ + +#endif // ULIB_UPRINTF_H_ diff --git a/user/init/main.c b/user/init/main.c index c686006..6ad6e8e 100644 --- a/user/init/main.c +++ b/user/init/main.c @@ -3,8 +3,7 @@ #include #include #include -#include -#include +#include void main(void) { debugprint("Hello world from userspace in C"); @@ -21,8 +20,7 @@ void main(void) { ioctl_closefile(ioh); - char *aba = "Hello!"; - ipcpipe(IPCPIPE_SELFPID, IPCPIPE_OUT, IPCPIPE_WRITE, (uint8_t *)aba, string_len(aba)); + uprintf("Hello world using uprintf\n"); for(;;); }