ref: 797f8bc3a2be6ddec3497496e9989ab66d21800e
dir: /src/asm/format.c/
/*
* This file is part of RGBDS.
*
* Copyright (c) 2020, RGBDS contributors.
*
* SPDX-License-Identifier: MIT
*/
#include <assert.h>
#include <inttypes.h>
#include <math.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "asm/fixpoint.h"
#include "asm/format.h"
#include "asm/warning.h"
struct FormatSpec fmt_NewSpec(void)
{
struct FormatSpec fmt = {0};
return fmt;
}
bool fmt_IsEmpty(struct FormatSpec const *fmt)
{
return !fmt->state;
}
bool fmt_IsValid(struct FormatSpec const *fmt)
{
return fmt->valid || fmt->state == FORMAT_DONE;
}
bool fmt_IsFinished(struct FormatSpec const *fmt)
{
return fmt->state >= FORMAT_DONE;
}
void fmt_UseCharacter(struct FormatSpec *fmt, int c)
{
if (fmt->state == FORMAT_INVALID)
return;
switch (c) {
// sign
case ' ':
case '+':
if (fmt->state > FORMAT_SIGN)
goto invalid;
fmt->state = FORMAT_PREFIX;
fmt->sign = c;
break;
// prefix
case '#':
if (fmt->state > FORMAT_PREFIX)
goto invalid;
fmt->state = FORMAT_ALIGN;
fmt->prefix = true;
break;
// align
case '-':
if (fmt->state > FORMAT_ALIGN)
goto invalid;
fmt->state = FORMAT_WIDTH;
fmt->alignLeft = true;
break;
// pad and width
case '0':
if (fmt->state < FORMAT_WIDTH)
fmt->padZero = true;
// fallthrough
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
if (fmt->state < FORMAT_WIDTH) {
fmt->state = FORMAT_WIDTH;
fmt->width = c - '0';
} else if (fmt->state == FORMAT_WIDTH) {
fmt->width = fmt->width * 10 + (c - '0');
} else if (fmt->state == FORMAT_FRAC) {
fmt->fracWidth = fmt->fracWidth * 10 + (c - '0');
} else {
goto invalid;
}
break;
case '.':
if (fmt->state > FORMAT_WIDTH)
goto invalid;
fmt->state = FORMAT_FRAC;
fmt->hasFrac = true;
break;
// type
case 'd':
case 'u':
case 'X':
case 'x':
case 'b':
case 'o':
case 'f':
case 's':
if (fmt->state >= FORMAT_DONE)
goto invalid;
fmt->state = FORMAT_DONE;
fmt->valid = true;
fmt->type = c;
break;
default:
invalid:
fmt->state = FORMAT_INVALID;
fmt->valid = false;
}
}
void fmt_FinishCharacters(struct FormatSpec *fmt)
{
if (!fmt_IsValid(fmt))
fmt->state = FORMAT_INVALID;
}
void fmt_PrintString(char *buf, size_t bufLen, struct FormatSpec const *fmt, char const *value)
{
if (fmt->sign)
error("Formatting string with sign flag '%c'\n", fmt->sign);
if (fmt->prefix)
error("Formatting string with prefix flag '#'\n");
if (fmt->padZero)
error("Formatting string with padding flag '0'\n");
if (fmt->hasFrac)
error("Formatting string with fractional width\n");
if (fmt->type != 's')
error("Formatting string as type '%c'\n", fmt->type);
size_t len = strlen(value);
size_t totalLen = fmt->width > len ? fmt->width : len;
if (totalLen > bufLen - 1) { // bufLen includes terminator
error("Formatted string value too long\n");
totalLen = bufLen - 1;
if (len > totalLen)
len = totalLen;
}
assert(len < bufLen && totalLen < bufLen && len <= totalLen);
size_t padLen = totalLen - len;
if (fmt->alignLeft) {
memcpy(buf, value, len);
for (size_t i = len; i < totalLen; i++)
buf[i] = ' ';
} else {
for (size_t i = 0; i < padLen; i++)
buf[i] = ' ';
memcpy(buf + padLen, value, len);
}
buf[totalLen] = '\0';
}
void fmt_PrintNumber(char *buf, size_t bufLen, struct FormatSpec const *fmt, uint32_t value)
{
if (fmt->type != 'X' && fmt->type != 'x' && fmt->type != 'b' && fmt->type != 'o'
&& fmt->prefix)
error("Formatting type '%c' with prefix flag '#'\n", fmt->type);
if (fmt->type != 'f' && fmt->hasFrac)
error("Formatting type '%c' with fractional width\n", fmt->type);
if (fmt->type == 's')
error("Formatting number as type 's'\n");
char sign = fmt->sign; // 0 or ' ' or '+'
if (fmt->type == 'd' || fmt->type == 'f') {
int32_t v = value;
if (v < 0 && v != INT32_MIN) {
sign = '-';
value = -v;
}
}
char prefix = !fmt->prefix ? 0
: fmt->type == 'X' ? '$'
: fmt->type == 'x' ? '$'
: fmt->type == 'b' ? '%'
: fmt->type == 'o' ? '&'
: 0;
char valueBuf[262]; // Max 5 digits + decimal + 255 fraction digits + terminator
if (fmt->type == 'b') {
// Special case for binary
char *ptr = valueBuf;
do {
*ptr++ = (value & 1) + '0';
value >>= 1;
} while (value);
*ptr = '\0';
// Reverse the digits
size_t valueLen = ptr - valueBuf;
for (size_t i = 0, j = valueLen - 1; i < j; i++, j--) {
char c = valueBuf[i];
valueBuf[i] = valueBuf[j];
valueBuf[j] = c;
}
} else if (fmt->type == 'f') {
// Special case for fixed-point
// Default fractional width (C's is 6 for "%f"; here 5 is enough for Q16.16)
size_t fracWidth = fmt->hasFrac ? fmt->fracWidth : 5;
if (fracWidth > 255) {
error("Fractional width %zu too long, limiting to 255\n",
fracWidth);
fracWidth = 255;
}
snprintf(valueBuf, sizeof(valueBuf), "%.*f", (int)fracWidth,
value / fix_PrecisionFactor());
} else {
char const *spec = fmt->type == 'd' ? "%" PRId32
: fmt->type == 'u' ? "%" PRIu32
: fmt->type == 'X' ? "%" PRIX32
: fmt->type == 'x' ? "%" PRIx32
: fmt->type == 'o' ? "%" PRIo32
: "%" PRId32;
snprintf(valueBuf, sizeof(valueBuf), spec, value);
}
size_t len = strlen(valueBuf);
size_t numLen = (sign != 0) + (prefix != 0) + len;
size_t totalLen = fmt->width > numLen ? fmt->width : numLen;
if (totalLen > bufLen - 1) { // bufLen includes terminator
error("Formatted numeric value too long\n");
totalLen = bufLen - 1;
if (numLen > totalLen) {
len -= numLen - totalLen;
numLen = totalLen;
}
}
assert(numLen < bufLen && totalLen < bufLen && numLen <= totalLen && len <= numLen);
size_t padLen = totalLen - numLen;
size_t pos = 0;
if (fmt->alignLeft) {
if (sign)
buf[pos++] = sign;
if (prefix)
buf[pos++] = prefix;
memcpy(buf + pos, valueBuf, len);
for (size_t i = pos + len; i < totalLen; i++)
buf[i] = ' ';
} else {
if (fmt->padZero) {
// sign, then prefix, then zero padding
if (sign)
buf[pos++] = sign;
if (prefix)
buf[pos++] = prefix;
for (size_t i = 0; i < padLen; i++)
buf[pos++] = '0';
} else {
// space padding, then sign, then prefix
for (size_t i = 0; i < padLen; i++)
buf[pos++] = ' ';
if (sign)
buf[pos++] = sign;
if (prefix)
buf[pos++] = prefix;
}
memcpy(buf + pos, valueBuf, len);
}
buf[totalLen] = '\0';
}