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Fixes #115: Unifying _ntoa_long and _ntoa_long_long into a single…
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… `ntoa` function.

* Defined an `NTOA_VALUE_TYPE` based on whether `long long` is supported.
* Using an `NTOA_ABS()` macro instead of repeating the one-liner code used earlier; and it eagerly casts to avoid problems with extremal negative values.
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@eyalroz
eyalroz committed Aug 3, 2021
1 parent 64e2b3e commit b232802
Showing 1 changed file with 21 additions and 48 deletions.
69 changes: 21 additions & 48 deletions printf.c
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Original file line number Diff line number Diff line change
Expand Up @@ -91,6 +91,12 @@
#define PRINTF_SUPPORT_PTRDIFF_LENGTH_MODIFIER 1
#endif

#if PRINTF_SUPPORT_LONG_LONG
#define NTOA_VALUE_TYPE unsigned long long
#else
#define NTOA_VALUE_TYPE unsigned long
#endif

///////////////////////////////////////////////////////////////////////////////

// The following will convert the number-of-digits into an exponential-notation literal
Expand Down Expand Up @@ -120,6 +126,7 @@
#include <float.h>
#endif

#define NTOA_ABS(_x) ( (_x) > 0 ? (NTOA_VALUE_TYPE)(_x) : -((NTOA_VALUE_TYPE)_x) )

// output function type
typedef void (*out_fct_type)(char character, void* buffer, size_t idx, size_t maxlen);
Expand Down Expand Up @@ -296,41 +303,8 @@ static size_t _ntoa_format(out_fct_type out, char* buffer, size_t idx, size_t ma
}


// internal itoa for 'long' type
static size_t _ntoa_long(out_fct_type out, char* buffer, size_t idx, size_t maxlen, unsigned long value, bool negative, unsigned long base, unsigned int precision, unsigned int width, unsigned int flags)
{
char buf[PRINTF_NTOA_BUFFER_SIZE];
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 != 8U) {
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_NTOA_BUFFER_SIZE));
}

return _ntoa_format(out, buffer, idx, maxlen, buf, len, negative, (unsigned int)base, precision, width, flags);
}


// internal itoa for 'long long' type
#if PRINTF_SUPPORT_LONG_LONG
static size_t _ntoa_long_long(out_fct_type out, char* buffer, size_t idx, size_t maxlen, unsigned long long value, bool negative, unsigned long long base, unsigned int precision, unsigned int width, unsigned int flags)
// internal itoa
static size_t _ntoa(out_fct_type out, char* buffer, size_t idx, size_t maxlen, NTOA_VALUE_TYPE value, bool negative, NTOA_VALUE_TYPE base, unsigned int precision, unsigned int width, unsigned int flags)
{
char buf[PRINTF_NTOA_BUFFER_SIZE];
size_t len = 0U;
Expand Down Expand Up @@ -359,7 +333,6 @@ static size_t _ntoa_long_long(out_fct_type out, char* buffer, size_t idx, size_t

return _ntoa_format(out, buffer, idx, maxlen, buf, len, negative, (unsigned int)base, precision, width, flags);
}
#endif // PRINTF_SUPPORT_LONG_LONG


#if PRINTF_SUPPORT_FLOAT_SPECIFIERS
Expand Down Expand Up @@ -617,10 +590,10 @@ static size_t _etoa(out_fct_type out, char* buffer, size_t idx, size_t maxlen, d
// output the exponential symbol
out((flags & FLAGS_UPPERCASE) ? 'E' : 'e', buffer, idx++, maxlen);
// output the exponent value
idx = _ntoa_long(out, buffer, idx, maxlen,
(unsigned long)((expval < 0) ? -expval : expval),
expval < 0, 10, 0, minwidth-1,
FLAGS_ZEROPAD | FLAGS_PLUS);
idx = _ntoa(out, buffer, idx, maxlen,
NTOA_ABS(expval),
expval < 0, 10, 0, minwidth-1,
FLAGS_ZEROPAD | FLAGS_PLUS);
// might need to right-pad spaces
if (flags & FLAGS_LEFT) {
while (idx - start_idx < width) out(' ', buffer, idx++, maxlen);
Expand Down Expand Up @@ -783,31 +756,31 @@ static int _vsnprintf(out_fct_type out, char* buffer, const size_t maxlen, const
if (flags & FLAGS_LONG_LONG) {
#if PRINTF_SUPPORT_LONG_LONG
const long long value = va_arg(va, long long);
idx = _ntoa_long_long(out, buffer, idx, maxlen, (unsigned long long)(value > 0 ? value : 0 - value), value < 0, base, precision, width, flags);
idx = _ntoa(out, buffer, idx, maxlen, NTOA_ABS(value), value < 0, base, precision, width, flags);
#endif
}
else if (flags & FLAGS_LONG) {
const long value = va_arg(va, long);
idx = _ntoa_long(out, buffer, idx, maxlen, (unsigned long)(value > 0 ? value : 0 - value), value < 0, base, precision, width, flags);
idx = _ntoa(out, buffer, idx, maxlen, NTOA_ABS(value), value < 0, base, precision, width, flags);
}
else {
const int value = (flags & FLAGS_CHAR) ? (signed char)va_arg(va, int) : (flags & FLAGS_SHORT) ? (short int)va_arg(va, int) : va_arg(va, int);
idx = _ntoa_long(out, buffer, idx, maxlen, (unsigned int)(value > 0 ? value : 0 - value), value < 0, base, precision, width, flags);
idx = _ntoa(out, buffer, idx, maxlen, NTOA_ABS(value), value < 0, base, precision, width, flags);
}
}
else {
// unsigned
if (flags & FLAGS_LONG_LONG) {
#if PRINTF_SUPPORT_LONG_LONG
idx = _ntoa_long_long(out, buffer, idx, maxlen, va_arg(va, unsigned long long), false, base, precision, width, flags);
idx = _ntoa(out, buffer, idx, maxlen, (NTOA_VALUE_TYPE) va_arg(va, unsigned long long), false, base, precision, width, flags);
#endif
}
else if (flags & FLAGS_LONG) {
idx = _ntoa_long(out, buffer, idx, maxlen, va_arg(va, unsigned long), false, base, precision, width, flags);
idx = _ntoa(out, buffer, idx, maxlen, (NTOA_VALUE_TYPE) va_arg(va, unsigned long), false, base, precision, width, flags);
}
else {
const unsigned int value = (flags & FLAGS_CHAR) ? (unsigned char)va_arg(va, unsigned int) : (flags & FLAGS_SHORT) ? (unsigned short int)va_arg(va, unsigned int) : va_arg(va, unsigned int);
idx = _ntoa_long(out, buffer, idx, maxlen, value, false, base, precision, width, flags);
idx = _ntoa(out, buffer, idx, maxlen, (NTOA_VALUE_TYPE) value, false, base, precision, width, flags);
}
}
format++;
Expand Down Expand Up @@ -895,11 +868,11 @@ static int _vsnprintf(out_fct_type out, char* buffer, const size_t maxlen, const
#if PRINTF_SUPPORT_LONG_LONG
const bool is_ll = sizeof(uintptr_t) == sizeof(long long);
if (is_ll) {
idx = _ntoa_long_long(out, buffer, idx, maxlen, value, false, 16U, precision, width, flags);
idx = _ntoa(out, buffer, idx, maxlen, (NTOA_VALUE_TYPE) value, false, 16U, precision, width, flags);
}
else {
#endif
idx = _ntoa_long(out, buffer, idx, maxlen, (unsigned long)((uintptr_t)va_arg(va, void*)), false, 16U, precision, width, flags);
idx = _ntoa(out, buffer, idx, maxlen, (NTOA_VALUE_TYPE)((uintptr_t)va_arg(va, void*)), false, 16U, precision, width, flags);
#if PRINTF_SUPPORT_LONG_LONG
}
#endif
Expand Down

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