/
nanoprintf.h
1116 lines (970 loc) · 36.1 KB
/
nanoprintf.h
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/* nanoprintf: a tiny embeddable printf replacement written in C.
https://github.com/charlesnicholson/nanoprintf
dual-licensed under 0bsd and unlicense, take your pick. see eof for details. */
#ifndef NANOPRINTF_H_INCLUDED
#define NANOPRINTF_H_INCLUDED
#include <stdarg.h>
#include <stddef.h>
// Define this to fully sandbox nanoprintf inside of a translation unit.
#ifdef NANOPRINTF_VISIBILITY_STATIC
#define NPF_VISIBILITY static
#else
#define NPF_VISIBILITY extern
#endif
#if defined(__clang__) || defined(__GNUC__) || defined(__GNUG__)
#define NPF_PRINTF_ATTR(FORMAT_INDEX, VARGS_INDEX) \
__attribute__((format(printf, FORMAT_INDEX, VARGS_INDEX)))
#else
#define NPF_PRINTF_ATTR(FORMAT_INDEX, VARGS_INDEX)
#endif
// Public API
#ifdef __cplusplus
extern "C" {
#endif
// The npf_ functions all return the number of bytes required to express the
// fully-formatted string, not including the null terminator character.
// The npf_ functions do not return negative values, since the lack of 'l' length
// modifier support makes encoding errors impossible.
NPF_VISIBILITY int npf_snprintf(
char *buffer, size_t bufsz, const char *format, ...) NPF_PRINTF_ATTR(3, 4);
NPF_VISIBILITY int npf_vsnprintf(
char *buffer, size_t bufsz, char const *format, va_list vlist) NPF_PRINTF_ATTR(3, 0);
typedef void (*npf_putc)(int c, void *ctx);
NPF_VISIBILITY int npf_pprintf(
npf_putc pc, void *pc_ctx, char const *format, ...) NPF_PRINTF_ATTR(3, 4);
NPF_VISIBILITY int npf_vpprintf(
npf_putc pc, void *pc_ctx, char const *format, va_list vlist) NPF_PRINTF_ATTR(3, 0);
#ifdef __cplusplus
}
#endif
#endif // NANOPRINTF_H_INCLUDED
/* The implementation of nanoprintf begins here, to be compiled only if
NANOPRINTF_IMPLEMENTATION is defined. In a multi-file library what follows would
be nanoprintf.c. */
#ifdef NANOPRINTF_IMPLEMENTATION
#ifndef NANOPRINTF_IMPLEMENTATION_INCLUDED
#define NANOPRINTF_IMPLEMENTATION_INCLUDED
#include <inttypes.h>
#include <stdint.h>
// Pick reasonable defaults if nothing's been configured.
#if !defined(NANOPRINTF_USE_FIELD_WIDTH_FORMAT_SPECIFIERS) && \
!defined(NANOPRINTF_USE_PRECISION_FORMAT_SPECIFIERS) && \
!defined(NANOPRINTF_USE_FLOAT_FORMAT_SPECIFIERS) && \
!defined(NANOPRINTF_USE_LARGE_FORMAT_SPECIFIERS) && \
!defined(NANOPRINTF_USE_BINARY_FORMAT_SPECIFIERS) && \
!defined(NANOPRINTF_USE_WRITEBACK_FORMAT_SPECIFIERS)
#define NANOPRINTF_USE_FIELD_WIDTH_FORMAT_SPECIFIERS 1
#define NANOPRINTF_USE_PRECISION_FORMAT_SPECIFIERS 1
#define NANOPRINTF_USE_FLOAT_FORMAT_SPECIFIERS 1
#define NANOPRINTF_USE_LARGE_FORMAT_SPECIFIERS 0
#define NANOPRINTF_USE_BINARY_FORMAT_SPECIFIERS 0
#define NANOPRINTF_USE_WRITEBACK_FORMAT_SPECIFIERS 0
#endif
// If anything's been configured, everything must be configured.
#ifndef NANOPRINTF_USE_FIELD_WIDTH_FORMAT_SPECIFIERS
#error NANOPRINTF_USE_FIELD_WIDTH_FORMAT_SPECIFIERS must be #defined to 0 or 1
#endif
#ifndef NANOPRINTF_USE_PRECISION_FORMAT_SPECIFIERS
#error NANOPRINTF_USE_PRECISION_FORMAT_SPECIFIERS must be #defined to 0 or 1
#endif
#ifndef NANOPRINTF_USE_FLOAT_FORMAT_SPECIFIERS
#error NANOPRINTF_USE_FLOAT_FORMAT_SPECIFIERS must be #defined to 0 or 1
#endif
#ifndef NANOPRINTF_USE_LARGE_FORMAT_SPECIFIERS
#error NANOPRINTF_USE_LARGE_FORMAT_SPECIFIERS must be #defined to 0 or 1
#endif
#ifndef NANOPRINTF_USE_BINARY_FORMAT_SPECIFIERS
#error NANOPRINTF_USE_BINARY_FORMAT_SPECIFIERS must be #defined to 0 or 1
#endif
#ifndef NANOPRINTF_USE_WRITEBACK_FORMAT_SPECIFIERS
#error NANOPRINTF_USE_WRITEBACK_FORMAT_SPECIFIERS must be #defined to 0 or 1
#endif
// Ensure flags are compatible.
#if (NANOPRINTF_USE_FLOAT_FORMAT_SPECIFIERS == 1) && \
(NANOPRINTF_USE_PRECISION_FORMAT_SPECIFIERS == 0)
#error Precision format specifiers must be enabled if float support is enabled.
#endif
// intmax_t / uintmax_t require stdint from c99 / c++11
#if NANOPRINTF_USE_LARGE_FORMAT_SPECIFIERS == 1
#ifndef _MSC_VER
#ifdef __cplusplus
#if __cplusplus < 201103L
#error large format specifier support requires C++11 or later.
#endif
#else
#if __STDC_VERSION__ < 199409L
#error nanoprintf requires C99 or later.
#endif
#endif
#endif
#endif
// Figure out if we can disable warnings with pragmas.
#ifdef __clang__
#define NANOPRINTF_CLANG 1
#define NANOPRINTF_GCC_PAST_4_6 0
#else
#define NANOPRINTF_CLANG 0
#if defined(__GNUC__) && ((__GNUC__ > 4) || ((__GNUC__ == 4) && (__GNUC_MINOR__ > 6)))
#define NANOPRINTF_GCC_PAST_4_6 1
#else
#define NANOPRINTF_GCC_PAST_4_6 0
#endif
#endif
#if NANOPRINTF_CLANG || NANOPRINTF_GCC_PAST_4_6
#define NANOPRINTF_HAVE_GCC_WARNING_PRAGMAS 1
#else
#define NANOPRINTF_HAVE_GCC_WARNING_PRAGMAS 0
#endif
#if NANOPRINTF_HAVE_GCC_WARNING_PRAGMAS
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-function"
#pragma GCC diagnostic ignored "-Wimplicit-fallthrough"
#ifdef __cplusplus
#pragma GCC diagnostic ignored "-Wold-style-cast"
#endif
#pragma GCC diagnostic ignored "-Wpadded"
#pragma GCC diagnostic ignored "-Wfloat-equal"
#if NANOPRINTF_CLANG
#pragma GCC diagnostic ignored "-Wc++98-compat-pedantic"
#pragma GCC diagnostic ignored "-Wcovered-switch-default"
#pragma GCC diagnostic ignored "-Wdeclaration-after-statement"
#ifndef __APPLE__
#pragma GCC diagnostic ignored "-Wunsafe-buffer-usage"
#endif
#elif NANOPRINTF_GCC_PAST_4_6
#pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
#endif
#endif
#ifdef _MSC_VER
#pragma warning(push)
#pragma warning(disable:4514) // unreferenced inline function removed
#pragma warning(disable:4505) // unreferenced function removed
#pragma warning(disable:4701) // possibly uninitialized
#pragma warning(disable:4706) // assignment in conditional
#pragma warning(disable:4710) // not inlined
#pragma warning(disable:4711) // selected for inline
#pragma warning(disable:4820) // padding after data member
#pragma warning(disable:5039) // extern "C" throw
#pragma warning(disable:5045) // spectre mitigation
#pragma warning(disable:5262) // implicit switch fall-through
#endif
#if (NANOPRINTF_USE_FIELD_WIDTH_FORMAT_SPECIFIERS == 1) || \
(NANOPRINTF_USE_PRECISION_FORMAT_SPECIFIERS == 1)
typedef enum {
NPF_FMT_SPEC_OPT_NONE,
NPF_FMT_SPEC_OPT_LITERAL,
NPF_FMT_SPEC_OPT_STAR,
} npf_fmt_spec_opt_t;
#endif
typedef enum {
NPF_FMT_SPEC_LEN_MOD_NONE,
NPF_FMT_SPEC_LEN_MOD_SHORT, // 'h'
NPF_FMT_SPEC_LEN_MOD_LONG_DOUBLE, // 'L'
NPF_FMT_SPEC_LEN_MOD_CHAR, // 'hh'
NPF_FMT_SPEC_LEN_MOD_LONG, // 'l'
#if NANOPRINTF_USE_LARGE_FORMAT_SPECIFIERS == 1
NPF_FMT_SPEC_LEN_MOD_LARGE_LONG_LONG, // 'll'
NPF_FMT_SPEC_LEN_MOD_LARGE_INTMAX, // 'j'
NPF_FMT_SPEC_LEN_MOD_LARGE_SIZET, // 'z'
NPF_FMT_SPEC_LEN_MOD_LARGE_PTRDIFFT, // 't'
#endif
} npf_format_spec_length_modifier_t;
typedef enum {
NPF_FMT_SPEC_CONV_PERCENT, // '%'
NPF_FMT_SPEC_CONV_CHAR, // 'c'
NPF_FMT_SPEC_CONV_STRING, // 's'
NPF_FMT_SPEC_CONV_SIGNED_INT, // 'i', 'd'
#if NANOPRINTF_USE_BINARY_FORMAT_SPECIFIERS == 1
NPF_FMT_SPEC_CONV_BINARY, // 'b'
#endif
NPF_FMT_SPEC_CONV_OCTAL, // 'o'
NPF_FMT_SPEC_CONV_HEX_INT, // 'x', 'X'
NPF_FMT_SPEC_CONV_UNSIGNED_INT, // 'u'
NPF_FMT_SPEC_CONV_POINTER, // 'p'
#if NANOPRINTF_USE_WRITEBACK_FORMAT_SPECIFIERS == 1
NPF_FMT_SPEC_CONV_WRITEBACK, // 'n'
#endif
#if NANOPRINTF_USE_FLOAT_FORMAT_SPECIFIERS == 1
NPF_FMT_SPEC_CONV_FLOAT_DEC, // 'f', 'F'
NPF_FMT_SPEC_CONV_FLOAT_SCI, // 'e', 'E'
NPF_FMT_SPEC_CONV_FLOAT_SHORTEST, // 'g', 'G'
NPF_FMT_SPEC_CONV_FLOAT_HEX, // 'a', 'A'
#endif
} npf_format_spec_conversion_t;
typedef struct npf_format_spec {
char prepend; // ' ' or '+'
char alt_form; // '#'
#if NANOPRINTF_USE_FIELD_WIDTH_FORMAT_SPECIFIERS == 1
npf_fmt_spec_opt_t field_width_opt;
int field_width;
char left_justified; // '-'
char leading_zero_pad; // '0'
#endif
#if NANOPRINTF_USE_PRECISION_FORMAT_SPECIFIERS == 1
npf_fmt_spec_opt_t prec_opt;
int prec;
#endif
npf_format_spec_length_modifier_t length_modifier;
npf_format_spec_conversion_t conv_spec;
char case_adjust;
} npf_format_spec_t;
#if NANOPRINTF_USE_LARGE_FORMAT_SPECIFIERS == 0
typedef long npf_int_t;
typedef unsigned long npf_uint_t;
#else
typedef intmax_t npf_int_t;
typedef uintmax_t npf_uint_t;
#endif
typedef struct npf_bufputc_ctx {
char *dst;
size_t len;
size_t cur;
} npf_bufputc_ctx_t;
static int npf_parse_format_spec(char const *format, npf_format_spec_t *out_spec);
static void npf_bufputc(int c, void *ctx);
static void npf_bufputc_nop(int c, void *ctx);
static int npf_itoa_rev(char *buf, npf_int_t i);
static int npf_utoa_rev(char *buf, npf_uint_t i, unsigned base, unsigned case_adjust);
#if NANOPRINTF_USE_FLOAT_FORMAT_SPECIFIERS == 1
static int npf_fsplit_abs(float f,
uint64_t *out_int_part,
uint64_t *out_frac_part,
int *out_frac_base10_neg_e);
static int npf_ftoa_rev(char *buf, float f, npf_format_spec_t const *spec, int *out_frac_chars);
#endif
#if NANOPRINTF_USE_BINARY_FORMAT_SPECIFIERS == 1
static int npf_bin_len(npf_uint_t i);
#endif
#if NANOPRINTF_USE_LARGE_FORMAT_SPECIFIERS == 1
#ifdef _MSC_VER
#include <BaseTsd.h>
typedef SSIZE_T ssize_t;
#else
#include <sys/types.h>
#endif
#endif
#ifdef _MSC_VER
#include <intrin.h>
#endif
static int npf_max(int x, int y) { return (x > y) ? x : y; }
int npf_parse_format_spec(char const *format, npf_format_spec_t *out_spec) {
char const *cur = format;
#if NANOPRINTF_USE_FIELD_WIDTH_FORMAT_SPECIFIERS == 1
out_spec->left_justified = 0;
out_spec->leading_zero_pad = 0;
#endif
out_spec->case_adjust = 'a'-'A'; // lowercase
out_spec->prepend = 0;
out_spec->alt_form = 0;
while (*++cur) { // cur points at the leading '%' character
switch (*cur) { // Optional flags
#if NANOPRINTF_USE_FIELD_WIDTH_FORMAT_SPECIFIERS == 1
case '-': out_spec->left_justified = '-'; out_spec->leading_zero_pad = 0; continue;
case '0': out_spec->leading_zero_pad = !out_spec->left_justified; continue;
#endif
case '+': out_spec->prepend = '+'; continue;
case ' ': if (out_spec->prepend == 0) { out_spec->prepend = ' '; } continue;
case '#': out_spec->alt_form = '#'; continue;
default: break;
}
break;
}
#if NANOPRINTF_USE_FIELD_WIDTH_FORMAT_SPECIFIERS == 1
out_spec->field_width_opt = NPF_FMT_SPEC_OPT_NONE;
if (*cur == '*') {
out_spec->field_width_opt = NPF_FMT_SPEC_OPT_STAR;
++cur;
} else {
out_spec->field_width = 0;
while ((*cur >= '0') && (*cur <= '9')) {
out_spec->field_width_opt = NPF_FMT_SPEC_OPT_LITERAL;
out_spec->field_width = (out_spec->field_width * 10) + (*cur++ - '0');
}
}
#endif
#if NANOPRINTF_USE_PRECISION_FORMAT_SPECIFIERS == 1
out_spec->prec = 0;
out_spec->prec_opt = NPF_FMT_SPEC_OPT_NONE;
if (*cur == '.') {
++cur;
if (*cur == '*') {
out_spec->prec_opt = NPF_FMT_SPEC_OPT_STAR;
++cur;
} else {
if (*cur == '-') {
++cur;
out_spec->prec_opt = NPF_FMT_SPEC_OPT_NONE;
} else {
out_spec->prec_opt = NPF_FMT_SPEC_OPT_LITERAL;
}
while ((*cur >= '0') && (*cur <= '9')) {
out_spec->prec = (out_spec->prec * 10) + (*cur++ - '0');
}
}
}
#endif
int tmp_conv = -1;
out_spec->length_modifier = NPF_FMT_SPEC_LEN_MOD_NONE;
switch (*cur++) { // Length modifier
case 'h':
out_spec->length_modifier = NPF_FMT_SPEC_LEN_MOD_SHORT;
if (*cur == 'h') {
out_spec->length_modifier = NPF_FMT_SPEC_LEN_MOD_CHAR;
++cur;
}
break;
case 'l':
out_spec->length_modifier = NPF_FMT_SPEC_LEN_MOD_LONG;
#if NANOPRINTF_USE_LARGE_FORMAT_SPECIFIERS == 1
if (*cur == 'l') {
out_spec->length_modifier = NPF_FMT_SPEC_LEN_MOD_LARGE_LONG_LONG;
++cur;
}
#endif
break;
#if NANOPRINTF_USE_FLOAT_FORMAT_SPECIFIERS == 1
case 'L': out_spec->length_modifier = NPF_FMT_SPEC_LEN_MOD_LONG_DOUBLE; break;
#endif
#if NANOPRINTF_USE_LARGE_FORMAT_SPECIFIERS == 1
case 'j': out_spec->length_modifier = NPF_FMT_SPEC_LEN_MOD_LARGE_INTMAX; break;
case 'z': out_spec->length_modifier = NPF_FMT_SPEC_LEN_MOD_LARGE_SIZET; break;
case 't': out_spec->length_modifier = NPF_FMT_SPEC_LEN_MOD_LARGE_PTRDIFFT; break;
#endif
default: --cur; break;
}
switch (*cur++) { // Conversion specifier
case '%': out_spec->conv_spec = NPF_FMT_SPEC_CONV_PERCENT;
#if NANOPRINTF_USE_PRECISION_FORMAT_SPECIFIERS == 1
out_spec->prec_opt = NPF_FMT_SPEC_OPT_NONE;
#endif
break;
case 'c': out_spec->conv_spec = NPF_FMT_SPEC_CONV_CHAR;
#if NANOPRINTF_USE_PRECISION_FORMAT_SPECIFIERS == 1
out_spec->prec_opt = NPF_FMT_SPEC_OPT_NONE;
#endif
break;
case 's': out_spec->conv_spec = NPF_FMT_SPEC_CONV_STRING;
#if NANOPRINTF_USE_FIELD_WIDTH_FORMAT_SPECIFIERS == 1
out_spec->leading_zero_pad = 0;
#endif
break;
case 'i':
case 'd': tmp_conv = NPF_FMT_SPEC_CONV_SIGNED_INT;
case 'o': if (tmp_conv == -1) { tmp_conv = NPF_FMT_SPEC_CONV_OCTAL; }
case 'u': if (tmp_conv == -1) { tmp_conv = NPF_FMT_SPEC_CONV_UNSIGNED_INT; }
case 'X': if (tmp_conv == -1) { out_spec->case_adjust = 0; }
case 'x': if (tmp_conv == -1) { tmp_conv = NPF_FMT_SPEC_CONV_HEX_INT; }
out_spec->conv_spec = (npf_format_spec_conversion_t)tmp_conv;
#if (NANOPRINTF_USE_FIELD_WIDTH_FORMAT_SPECIFIERS == 1) && \
(NANOPRINTF_USE_PRECISION_FORMAT_SPECIFIERS == 1)
if (out_spec->prec_opt != NPF_FMT_SPEC_OPT_NONE) { out_spec->leading_zero_pad = 0; }
#endif
break;
#if NANOPRINTF_USE_FLOAT_FORMAT_SPECIFIERS == 1
case 'F': out_spec->case_adjust = 0;
case 'f':
out_spec->conv_spec = NPF_FMT_SPEC_CONV_FLOAT_DEC;
if (out_spec->prec_opt == NPF_FMT_SPEC_OPT_NONE) { out_spec->prec = 6; }
break;
case 'E': out_spec->case_adjust = 0;
case 'e':
out_spec->conv_spec = NPF_FMT_SPEC_CONV_FLOAT_SCI;
if (out_spec->prec_opt == NPF_FMT_SPEC_OPT_NONE) { out_spec->prec = 6; }
break;
case 'G': out_spec->case_adjust = 0;
case 'g':
out_spec->conv_spec = NPF_FMT_SPEC_CONV_FLOAT_SHORTEST;
if (out_spec->prec_opt == NPF_FMT_SPEC_OPT_NONE) { out_spec->prec = 6; }
break;
case 'A': out_spec->case_adjust = 0;
case 'a':
out_spec->conv_spec = NPF_FMT_SPEC_CONV_FLOAT_HEX;
if (out_spec->prec_opt == NPF_FMT_SPEC_OPT_NONE) { out_spec->prec = 6; }
break;
#endif
#if NANOPRINTF_USE_WRITEBACK_FORMAT_SPECIFIERS == 1
case 'n':
// todo: reject string if flags or width or precision exist
out_spec->conv_spec = NPF_FMT_SPEC_CONV_WRITEBACK;
#if NANOPRINTF_USE_PRECISION_FORMAT_SPECIFIERS == 1
out_spec->prec_opt = NPF_FMT_SPEC_OPT_NONE;
#endif
break;
#endif
case 'p':
out_spec->conv_spec = NPF_FMT_SPEC_CONV_POINTER;
#if NANOPRINTF_USE_PRECISION_FORMAT_SPECIFIERS == 1
out_spec->prec_opt = NPF_FMT_SPEC_OPT_NONE;
#endif
break;
#if NANOPRINTF_USE_BINARY_FORMAT_SPECIFIERS == 1
case 'B':
out_spec->case_adjust = 0;
case 'b':
out_spec->conv_spec = NPF_FMT_SPEC_CONV_BINARY;
break;
#endif
default: return 0;
}
return (int)(cur - format);
}
int npf_itoa_rev(char *buf, npf_int_t i) {
int n = 0;
int const sign = (i >= 0) ? 1 : -1;
do { *buf++ = (char)('0' + (sign * (i % 10))); i /= 10; ++n; } while (i);
return n;
}
int npf_utoa_rev(char *buf, npf_uint_t i, unsigned base, unsigned case_adj) {
int n = 0;
do {
unsigned const d = (unsigned)(i % base);
*buf++ = (char)((d < 10) ? ('0' + d) : ('A' + case_adj + (d - 10)));
i /= base;
++n;
} while (i);
return n;
}
#if NANOPRINTF_USE_FLOAT_FORMAT_SPECIFIERS == 1
enum {
NPF_MANTISSA_BITS = 23,
NPF_EXPONENT_BITS = 8,
NPF_EXPONENT_BIAS = 127,
NPF_FRACTION_BIN_DIGITS = 64,
NPF_MAX_FRACTION_DEC_DIGITS = 9
};
int npf_fsplit_abs(float f, uint64_t *out_int_part, uint64_t *out_frac_part,
int *out_frac_base10_neg_exp) {
/* conversion algorithm by Wojciech Muła (zdję[email protected])
http://0x80.pl/notesen/2015-12-29-float-to-string.html
grisu2 (https://bit.ly/2JgMggX) and ryu (https://bit.ly/2RLXSg0)
are fast + precise + round, but require large lookup tables. */
uint32_t f_bits; { // union-cast is UB, let compiler optimize byte-copy loop.
char const *src = (char const *)&f;
char *dst = (char *)&f_bits;
for (unsigned i = 0; i < sizeof(f_bits); ++i) { dst[i] = src[i]; }
}
int const exponent =
((int)((f_bits >> NPF_MANTISSA_BITS) & ((1u << NPF_EXPONENT_BITS) - 1u)) -
NPF_EXPONENT_BIAS) - NPF_MANTISSA_BITS;
if (exponent >= (64 - NPF_MANTISSA_BITS)) { return 0; } // value is out of range
uint32_t const implicit_one = ((uint32_t)1) << NPF_MANTISSA_BITS;
uint32_t const mantissa = f_bits & (implicit_one - 1);
uint32_t const mantissa_norm = mantissa | implicit_one;
if (exponent > 0) {
*out_int_part = (uint64_t)mantissa_norm << exponent;
} else if (exponent < 0) {
if (-exponent > NPF_MANTISSA_BITS) {
*out_int_part = 0;
} else {
*out_int_part = mantissa_norm >> -exponent;
}
} else {
*out_int_part = mantissa_norm;
}
uint64_t frac; {
int const shift = NPF_FRACTION_BIN_DIGITS + exponent - 4;
if ((shift >= (NPF_FRACTION_BIN_DIGITS - 4)) || (shift < 0)) {
frac = 0;
} else {
frac = ((uint64_t)mantissa_norm) << shift;
}
// multiply off the leading one's digit
frac &= 0x0fffffffffffffffllu;
frac *= 10;
}
{ // Count the number of 0s at the beginning of the fractional part.
int frac_base10_neg_exp = 0;
while (frac && ((frac >> (NPF_FRACTION_BIN_DIGITS - 4))) == 0) {
++frac_base10_neg_exp;
frac &= 0x0fffffffffffffffllu;
frac *= 10;
}
*out_frac_base10_neg_exp = frac_base10_neg_exp;
}
{ // Convert the fractional part to base 10.
uint64_t frac_part = 0;
for (int i = 0; frac && (i < NPF_MAX_FRACTION_DEC_DIGITS); ++i) {
frac_part *= 10;
frac_part += (uint64_t)(frac >> (NPF_FRACTION_BIN_DIGITS - 4));
frac &= 0x0fffffffffffffffllu;
frac *= 10;
}
*out_frac_part = frac_part;
}
return 1;
}
int npf_ftoa_rev(char *buf, float f, npf_format_spec_t const *spec, int *out_frac_chars) {
uint32_t f_bits; { // union-cast is UB, let compiler optimize byte-copy loop.
char const *src = (char const *)&f;
char *dst = (char *)&f_bits;
for (unsigned i = 0; i < sizeof(f_bits); ++i) { dst[i] = src[i]; }
}
if ((uint8_t)(f_bits >> 23) == 0xFF) {
if (f_bits & 0x7fffff) {
for (int i = 0; i < 3; ++i) { *buf++ = (char)("NAN"[i] + spec->case_adjust); }
} else {
for (int i = 0; i < 3; ++i) { *buf++ = (char)("FNI"[i] + spec->case_adjust); }
}
return -3;
}
uint64_t int_part, frac_part;
int frac_base10_neg_exp;
if (npf_fsplit_abs(f, &int_part, &frac_part, &frac_base10_neg_exp) == 0) {
for (int i = 0; i < 3; ++i) { *buf++ = (char)("ROO"[i] + spec->case_adjust); }
return -3;
}
char *dst = buf;
while (frac_part) { // write the fractional digits
*dst++ = (char)('0' + (frac_part % 10));
frac_part /= 10;
}
// write the 0 digits between the . and the first fractional digit
while (frac_base10_neg_exp-- > 0) { *dst++ = '0'; }
*out_frac_chars = (int)(dst - buf);
// round the value to the specified precision
if (spec->prec < *out_frac_chars) {
char *digit = dst - spec->prec - 1;
unsigned carry = (*digit >= '5');
while (carry && (++digit < dst)) {
carry = (*digit == '9');
*digit = carry ? '0' : (*digit + 1);
}
int_part += carry; // overflow is not possible
}
*dst++ = '.';
// write the integer digits
do { *dst++ = (char)('0' + (int_part % 10)); int_part /= 10; } while (int_part);
return (int)(dst - buf);
}
#endif // NANOPRINTF_USE_FLOAT_FORMAT_SPECIFIERS
#if NANOPRINTF_USE_BINARY_FORMAT_SPECIFIERS == 1
int npf_bin_len(npf_uint_t u) {
// Return the length of the binary string format of 'u', preferring intrinsics.
if (!u) { return 1; }
#ifdef _MSC_VER // Win64, use _BSR64 for everything. If x86, use _BSR when non-large.
#ifdef _M_X64
#define NPF_HAVE_BUILTIN_CLZ
#define NPF_CLZ _BitScanReverse64
#elif NANOPRINTF_USE_LARGE_FORMAT_SPECIFIERS == 0
#define NPF_HAVE_BUILTIN_CLZ
#define NPF_CLZ _BitScanReverse
#endif
#ifdef NPF_HAVE_BUILTIN_CLZ
unsigned long idx;
NPF_CLZ(&idx, u);
return (int)(idx + 1);
#endif
#elif defined(NANOPRINTF_CLANG) || defined(NANOPRINTF_GCC_PAST_4_6)
#define NPF_HAVE_BUILTIN_CLZ
#if NANOPRINTF_USE_LARGE_FORMAT_SPECIFIERS == 1
#define NPF_CLZ(X) ((sizeof(long long) * 8) - (size_t)__builtin_clzll(X))
#else
#define NPF_CLZ(X) ((sizeof(long) * 8) - (size_t)__builtin_clzl(X))
#endif
return (int)NPF_CLZ(u);
#endif
#ifndef NPF_HAVE_BUILTIN_CLZ
int n;
for (n = 0; u; ++n, u >>= 1); // slow but small software fallback
return n;
#else
#undef NPF_HAVE_BUILTIN_CLZ
#undef NPF_CLZ
#endif
}
#endif
void npf_bufputc(int c, void *ctx) {
npf_bufputc_ctx_t *bpc = (npf_bufputc_ctx_t *)ctx;
if (bpc->cur < bpc->len) { bpc->dst[bpc->cur++] = (char)c; }
}
void npf_bufputc_nop(int c, void *ctx) { (void)c; (void)ctx; }
typedef struct npf_cnt_putc_ctx {
npf_putc pc;
void *ctx;
int n;
} npf_cnt_putc_ctx_t;
static void npf_putc_cnt(int c, void *ctx) {
npf_cnt_putc_ctx_t *pc_cnt = (npf_cnt_putc_ctx_t *)ctx;
++pc_cnt->n;
pc_cnt->pc(c, pc_cnt->ctx); // sibling-call optimization
}
#define NPF_PUTC(VAL) do { npf_putc_cnt((int)(VAL), &pc_cnt); } while (0)
#define NPF_EXTRACT(MOD, CAST_TO, EXTRACT_AS) \
case NPF_FMT_SPEC_LEN_MOD_##MOD: val = (CAST_TO)va_arg(args, EXTRACT_AS); break
#define NPF_WRITEBACK(MOD, TYPE) \
case NPF_FMT_SPEC_LEN_MOD_##MOD: *(va_arg(args, TYPE *)) = (TYPE)pc_cnt.n; break
int npf_vpprintf(npf_putc pc, void *pc_ctx, char const *format, va_list args) {
npf_format_spec_t fs;
char const *cur = format;
npf_cnt_putc_ctx_t pc_cnt;
pc_cnt.pc = pc;
pc_cnt.ctx = pc_ctx;
pc_cnt.n = 0;
while (*cur) {
int const fs_len = (*cur != '%') ? 0 : npf_parse_format_spec(cur, &fs);
if (!fs_len) { NPF_PUTC(*cur++); continue; }
cur += fs_len;
// Extract star-args immediately
#if NANOPRINTF_USE_FIELD_WIDTH_FORMAT_SPECIFIERS == 1
if (fs.field_width_opt == NPF_FMT_SPEC_OPT_STAR) {
fs.field_width_opt = NPF_FMT_SPEC_OPT_LITERAL;
fs.field_width = va_arg(args, int);
if (fs.field_width < 0) {
fs.field_width = -fs.field_width;
fs.left_justified = 1;
}
}
#endif
#if NANOPRINTF_USE_PRECISION_FORMAT_SPECIFIERS == 1
if (fs.prec_opt == NPF_FMT_SPEC_OPT_STAR) {
fs.prec_opt = NPF_FMT_SPEC_OPT_NONE;
fs.prec = va_arg(args, int);
if (fs.prec >= 0) { fs.prec_opt = NPF_FMT_SPEC_OPT_LITERAL; }
}
#endif
union { char cbuf_mem[32]; npf_uint_t binval; } u;
char *cbuf = u.cbuf_mem, sign_c = 0;
int cbuf_len = 0, need_0x = 0;
#if NANOPRINTF_USE_FIELD_WIDTH_FORMAT_SPECIFIERS == 1
int field_pad = 0;
char pad_c = 0;
#endif
#if NANOPRINTF_USE_PRECISION_FORMAT_SPECIFIERS == 1
int prec_pad = 0;
#if NANOPRINTF_USE_FIELD_WIDTH_FORMAT_SPECIFIERS == 1
int zero = 0;
#endif
#endif
#if NANOPRINTF_USE_FLOAT_FORMAT_SPECIFIERS == 1
int frac_chars = 0, inf_or_nan = 0;
#endif
// Extract and convert the argument to string, point cbuf at the text.
switch (fs.conv_spec) {
case NPF_FMT_SPEC_CONV_PERCENT:
*cbuf = '%';
cbuf_len = 1;
break;
case NPF_FMT_SPEC_CONV_CHAR:
*cbuf = (char)va_arg(args, int);
cbuf_len = 1;
break;
case NPF_FMT_SPEC_CONV_STRING: {
cbuf = va_arg(args, char *);
#if NANOPRINTF_USE_PRECISION_FORMAT_SPECIFIERS == 1
for (char const *s = cbuf;
((fs.prec_opt == NPF_FMT_SPEC_OPT_NONE) || (cbuf_len < fs.prec)) && *s;
++s, ++cbuf_len);
#else
for (char const *s = cbuf; *s; ++s, ++cbuf_len); // strlen
#endif
} break;
case NPF_FMT_SPEC_CONV_SIGNED_INT: {
npf_int_t val = 0;
switch (fs.length_modifier) {
NPF_EXTRACT(NONE, int, int);
NPF_EXTRACT(SHORT, short, int);
NPF_EXTRACT(LONG_DOUBLE, int, int);
NPF_EXTRACT(CHAR, char, int);
NPF_EXTRACT(LONG, long, long);
#if NANOPRINTF_USE_LARGE_FORMAT_SPECIFIERS == 1
NPF_EXTRACT(LARGE_LONG_LONG, long long, long long);
NPF_EXTRACT(LARGE_INTMAX, intmax_t, intmax_t);
NPF_EXTRACT(LARGE_SIZET, ssize_t, ssize_t);
NPF_EXTRACT(LARGE_PTRDIFFT, ptrdiff_t, ptrdiff_t);
#endif
default: break;
}
sign_c = (val < 0) ? '-' : fs.prepend;
#if NANOPRINTF_USE_PRECISION_FORMAT_SPECIFIERS == 1
#if NANOPRINTF_USE_FIELD_WIDTH_FORMAT_SPECIFIERS == 1
zero = !val;
#endif
// special case, if prec and value are 0, skip
if (!val && (fs.prec_opt == NPF_FMT_SPEC_OPT_LITERAL) && !fs.prec) {
cbuf_len = 0;
} else
#endif
{ cbuf_len = npf_itoa_rev(cbuf, val); }
} break;
#if NANOPRINTF_USE_BINARY_FORMAT_SPECIFIERS == 1
case NPF_FMT_SPEC_CONV_BINARY:
#endif
case NPF_FMT_SPEC_CONV_OCTAL:
case NPF_FMT_SPEC_CONV_HEX_INT:
case NPF_FMT_SPEC_CONV_UNSIGNED_INT: {
npf_uint_t val = 0;
switch (fs.length_modifier) {
NPF_EXTRACT(NONE, unsigned, unsigned);
NPF_EXTRACT(SHORT, unsigned short, unsigned);
NPF_EXTRACT(LONG_DOUBLE, unsigned, unsigned);
NPF_EXTRACT(CHAR, unsigned char, unsigned);
NPF_EXTRACT(LONG, unsigned long, unsigned long);
#if NANOPRINTF_USE_LARGE_FORMAT_SPECIFIERS == 1
NPF_EXTRACT(LARGE_LONG_LONG, unsigned long long, unsigned long long);
NPF_EXTRACT(LARGE_INTMAX, uintmax_t, uintmax_t);
NPF_EXTRACT(LARGE_SIZET, size_t, size_t);
NPF_EXTRACT(LARGE_PTRDIFFT, size_t, size_t);
#endif
default: break;
}
#if NANOPRINTF_USE_PRECISION_FORMAT_SPECIFIERS == 1
#if NANOPRINTF_USE_FIELD_WIDTH_FORMAT_SPECIFIERS == 1
zero = !val;
#endif
if (!val && (fs.prec_opt == NPF_FMT_SPEC_OPT_LITERAL) && !fs.prec) {
// Zero value and explicitly-requested zero precision means "print nothing".
if ((fs.conv_spec == NPF_FMT_SPEC_CONV_OCTAL) && fs.alt_form) {
fs.prec = 1; // octal special case, print a single '0'
}
} else
#endif
#if NANOPRINTF_USE_BINARY_FORMAT_SPECIFIERS == 1
if (fs.conv_spec == NPF_FMT_SPEC_CONV_BINARY) {
cbuf_len = npf_bin_len(val); u.binval = val;
} else
#endif
{
unsigned const base = (fs.conv_spec == NPF_FMT_SPEC_CONV_OCTAL) ?
8u : ((fs.conv_spec == NPF_FMT_SPEC_CONV_HEX_INT) ? 16u : 10u);
cbuf_len = npf_utoa_rev(cbuf, val, base, (unsigned)fs.case_adjust);
}
if (val && fs.alt_form && (fs.conv_spec == NPF_FMT_SPEC_CONV_OCTAL)) {
cbuf[cbuf_len++] = '0'; // OK to add leading octal '0' immediately.
}
if (val && fs.alt_form) { // 0x or 0b but can't write it yet.
if (fs.conv_spec == NPF_FMT_SPEC_CONV_HEX_INT) { need_0x = 'X'; }
#if NANOPRINTF_USE_BINARY_FORMAT_SPECIFIERS == 1
else if (fs.conv_spec == NPF_FMT_SPEC_CONV_BINARY) { need_0x = 'B'; }
#endif
if (need_0x) { need_0x += fs.case_adjust; }
}
} break;
case NPF_FMT_SPEC_CONV_POINTER: {
cbuf_len =
npf_utoa_rev(cbuf, (npf_uint_t)(uintptr_t)va_arg(args, void *), 16, 'a'-'A');
need_0x = 'x';
} break;
#if NANOPRINTF_USE_WRITEBACK_FORMAT_SPECIFIERS == 1
case NPF_FMT_SPEC_CONV_WRITEBACK:
switch (fs.length_modifier) {
NPF_WRITEBACK(NONE, int);
NPF_WRITEBACK(SHORT, short);
NPF_WRITEBACK(LONG, long);
NPF_WRITEBACK(LONG_DOUBLE, double);
NPF_WRITEBACK(CHAR, signed char);
#if NANOPRINTF_USE_LARGE_FORMAT_SPECIFIERS == 1
NPF_WRITEBACK(LARGE_LONG_LONG, long long);
NPF_WRITEBACK(LARGE_INTMAX, intmax_t);
NPF_WRITEBACK(LARGE_SIZET, size_t);
NPF_WRITEBACK(LARGE_PTRDIFFT, ptrdiff_t);
#endif
default: break;
} break;
#endif
#if NANOPRINTF_USE_FLOAT_FORMAT_SPECIFIERS == 1
case NPF_FMT_SPEC_CONV_FLOAT_DEC:
case NPF_FMT_SPEC_CONV_FLOAT_SCI:
case NPF_FMT_SPEC_CONV_FLOAT_SHORTEST:
case NPF_FMT_SPEC_CONV_FLOAT_HEX: {
float val;
if (fs.length_modifier == NPF_FMT_SPEC_LEN_MOD_LONG_DOUBLE) {
val = (float)va_arg(args, long double);
} else {
val = (float)va_arg(args, double);
}
sign_c = (val < 0.f) ? '-' : fs.prepend;
#if NANOPRINTF_USE_FIELD_WIDTH_FORMAT_SPECIFIERS == 1
zero = (val == 0.f);
#endif
cbuf_len = npf_ftoa_rev(cbuf, val, &fs, &frac_chars);
if (cbuf_len < 0) {
cbuf_len = -cbuf_len;
inf_or_nan = 1;
} else {
int const prec_adj = npf_max(0, frac_chars - fs.prec);
cbuf += prec_adj;
cbuf_len -= prec_adj;
}
} break;
#endif
default: break;
}
#if NANOPRINTF_USE_FIELD_WIDTH_FORMAT_SPECIFIERS == 1
// Compute the field width pad character
if (fs.field_width_opt == NPF_FMT_SPEC_OPT_LITERAL) {
if (fs.leading_zero_pad) { // '0' flag is only legal with numeric types
if ((fs.conv_spec != NPF_FMT_SPEC_CONV_STRING) &&
(fs.conv_spec != NPF_FMT_SPEC_CONV_CHAR) &&
(fs.conv_spec != NPF_FMT_SPEC_CONV_PERCENT)) {
#if NANOPRINTF_USE_PRECISION_FORMAT_SPECIFIERS == 1
if ((fs.prec_opt == NPF_FMT_SPEC_OPT_LITERAL) && !fs.prec && zero) {
pad_c = ' ';
} else
#endif
{ pad_c = '0'; }
}
} else { pad_c = ' '; }
}
#endif
// Compute the number of bytes to truncate or '0'-pad.
if (fs.conv_spec != NPF_FMT_SPEC_CONV_STRING) {
#if NANOPRINTF_USE_FLOAT_FORMAT_SPECIFIERS == 1
if (!inf_or_nan) { // float precision is after the decimal point
int const prec_start =
(fs.conv_spec == NPF_FMT_SPEC_CONV_FLOAT_DEC) ? frac_chars : cbuf_len;
prec_pad = npf_max(0, fs.prec - prec_start);
}
#elif NANOPRINTF_USE_PRECISION_FORMAT_SPECIFIERS == 1
prec_pad = npf_max(0, fs.prec - cbuf_len);
#endif
}
#if NANOPRINTF_USE_FIELD_WIDTH_FORMAT_SPECIFIERS == 1
// Given the full converted length, how many pad bytes?
field_pad = fs.field_width - cbuf_len - !!sign_c;
if (need_0x) { field_pad -= 2; }
#if NANOPRINTF_USE_FLOAT_FORMAT_SPECIFIERS == 1
if ((fs.conv_spec == NPF_FMT_SPEC_CONV_FLOAT_DEC) && !fs.prec && !fs.alt_form) {
++field_pad; // 0-pad, no decimal point.
}
#endif
#if NANOPRINTF_USE_PRECISION_FORMAT_SPECIFIERS == 1
field_pad -= prec_pad;
#endif
field_pad = npf_max(0, field_pad);
#endif // NANOPRINTF_USE_FIELD_WIDTH_FORMAT_SPECIFIERS
#if NANOPRINTF_USE_FIELD_WIDTH_FORMAT_SPECIFIERS == 1
// Apply right-justified field width if requested
if (!fs.left_justified && pad_c) { // If leading zeros pad, sign goes first.
if (pad_c == '0') {
if (sign_c) { NPF_PUTC(sign_c); sign_c = 0; }
// Pad byte is '0', write '0x' before '0' pad chars.
if (need_0x) { NPF_PUTC('0'); NPF_PUTC(need_0x); }
}
while (field_pad-- > 0) { NPF_PUTC(pad_c); }
// Pad byte is ' ', write '0x' after ' ' pad chars but before number.
if ((pad_c != '0') && need_0x) { NPF_PUTC('0'); NPF_PUTC(need_0x); }
} else
#endif
{ if (need_0x) { NPF_PUTC('0'); NPF_PUTC(need_0x); } } // no pad, '0x' requested.
// Write the converted payload
if (fs.conv_spec == NPF_FMT_SPEC_CONV_STRING) {
for (int i = 0; i < cbuf_len; ++i) { NPF_PUTC(cbuf[i]); }
} else {
if (sign_c) { NPF_PUTC(sign_c); }
#if NANOPRINTF_USE_FLOAT_FORMAT_SPECIFIERS == 1
if (fs.conv_spec != NPF_FMT_SPEC_CONV_FLOAT_DEC) {
#endif
#if NANOPRINTF_USE_PRECISION_FORMAT_SPECIFIERS == 1
while (prec_pad-- > 0) { NPF_PUTC('0'); } // int precision leads.
#endif
#if NANOPRINTF_USE_FLOAT_FORMAT_SPECIFIERS == 1
} else {
// if 0 precision, skip the fractional part and '.'
// if 0 prec + alternative form, keep the '.'
if (!fs.prec && !fs.alt_form) { ++cbuf; --cbuf_len; }
}
#endif
#if NANOPRINTF_USE_BINARY_FORMAT_SPECIFIERS == 1
if (fs.conv_spec == NPF_FMT_SPEC_CONV_BINARY) {
while (cbuf_len) { NPF_PUTC('0' + ((u.binval >> --cbuf_len) & 1)); }
} else
#endif
{ while (cbuf_len-- > 0) { NPF_PUTC(cbuf[cbuf_len]); } } // payload is reversed
#if NANOPRINTF_USE_FLOAT_FORMAT_SPECIFIERS == 1
// real precision comes after the number.
if ((fs.conv_spec == NPF_FMT_SPEC_CONV_FLOAT_DEC) && !inf_or_nan) {
while (prec_pad-- > 0) { NPF_PUTC('0'); }
}
#endif