/**************************************************************************//*****
* @file printf.c
* @brief Implementation of several stdio.h methods, such as printf(),
* sprintf() and so on. This reduces the memory footprint of the
* binary when using those methods, compared to the libc implementation.
********************************************************************************/
#include <stdio.h>
#include <stdarg.h>
#include "print.h"
/** Maximum string size allowed (in bytes). */
#define MAX_STRING_SIZE 100
/** Required for proper compilation. */
struct _reent r = {0, (FILE *) 0, (FILE *) 1, (FILE *) 0};
//struct _reent *_impure_ptr = &r;
/**
* @brief Writes a character inside the given string. Returns 1.
*
* @param pStr Storage string.
* @param c Character to write.
*/
signed int PutChar(char *pStr, char c)
{
*pStr = c;
return 1;
}
/**
* @brief Writes a string inside the given string.
*
* @param pStr Storage string.
* @param pSource Source string.
* @return The size of the written
*/
signed int PutString(char *pStr, const char *pSource)
{
signed int num = 0;
while (*pSource != 0) {
*pStr++ = *pSource++;
num++;
}
return num;
}
/**
* @brief Writes an unsigned int inside the given string, using the provided fill &
* width parameters.
*
* @param pStr Storage string.
* @param fill Fill character.
* @param width Minimum integer width.
* @param value Integer value.
*/
signed int PutUnsignedInt(
char *pStr,
char fill,
signed int width,
unsigned int value)
{
signed int num = 0;
/* Take current digit into account when calculating width */
width--;
/* Recursively write upper digits */
if ((value / 10) > 0) {
num = PutUnsignedInt(pStr, fill, width, value / 10);
pStr += num;
}
/* Write filler characters */
else {
while (width > 0) {
PutChar(pStr, fill);
pStr++;
num++;
width--;
}
}
/* Write lower digit */
num += PutChar(pStr, (value % 10) + '0');
return num;
}
/**
* @brief Writes a signed int inside the given string, using the provided fill & width
* parameters.
*
* @param pStr Storage string.
* @param fill Fill character.
* @param width Minimum integer width.
* @param value Signed integer value.
*/
signed int PutSignedInt(
char *pStr,
char fill,
signed int width,
signed int value)
{
signed int num = 0;
unsigned int absolute;
/* Compute absolute value */
if (value < 0) {
absolute = -value;
}
else {
absolute = value;
}
/* Take current digit into account when calculating width */
width--;
/* Recursively write upper digits */
if ((absolute / 10) > 0) {
if (value < 0) {
num = PutSignedInt(pStr, fill, width, -(absolute / 10));
}
else {
num = PutSignedInt(pStr, fill, width, absolute / 10);
}
pStr += num;
}
else {
/* Reserve space for sign */
if (value < 0) {
width--;
}
/* Write filler characters */
while (width > 0) {
PutChar(pStr, fill);
pStr++;
num++;
width--;
}
/* Write sign */
if (value < 0) {
num += PutChar(pStr, '-');
pStr++;
}
}
/* Write lower digit */
num += PutChar(pStr, (absolute % 10) + '0');
return num;
}
/**
* @brief Writes an hexadecimal value into a string, using the given fill, width &
* capital parameters.
*
* @param pStr Storage string.
* @param fill Fill character.
* @param width Minimum integer width.
* @param maj Indicates if the letters must be printed in lower- or upper-case.
* @param value Hexadecimal value.
*
* @return The number of char written
*/
signed int PutHexa(
char *pStr,
char fill,
signed int width,
unsigned char maj,
unsigned int value)
{
signed int num = 0;
/* Decrement width */
width--;
/* Recursively output upper digits */
if ((value >> 4) > 0) {
num += PutHexa(pStr, fill, width, maj, value >> 4);
pStr += num;
}
/* Write filler chars */
else {
while (width > 0) {
PutChar(pStr, fill);
pStr++;
num++;
width--;
}
}
/* Write current digit */
if ((value & 0xF) < 10) {
PutChar(pStr, (value & 0xF) + '0');
}
else if (maj) {
PutChar(pStr, (value & 0xF) - 10 + 'A');
}
else {
PutChar(pStr, (value & 0xF) - 10 + 'a');
}
num++;
return num;
}
/* Global Functions ----------------------------------------------------------- */
/**
* @brief Stores the result of a formatted string into another string. Format
* arguments are given in a va_list instance.
*
* @param pStr Destination string.
* @param length Length of Destination string.
* @param pFormat Format string.
* @param ap Argument list.
*
* @return The number of characters written.
*/
signed int vsnprintf(char *pStr, size_t length, const char *pFormat, va_list ap)
{
char fill;
unsigned char width;
signed int num = 0;
signed int size = 0;
/* Clear the string */
if (pStr) {
*pStr = 0;
}
/* Phase string */
while (*pFormat != 0 && size < length) {
/* Normal character */
if (*pFormat != '%') {
*pStr++ = *pFormat++;
size++;
}
/* Escaped '%' */
else if (*(pFormat+1) == '%') {
*pStr++ = '%';
pFormat += 2;
size++;
}
/* Token delimiter */
else {
fill = ' ';
width = 0;
pFormat++;
/* Parse filler */
if (*pFormat == '0') {
fill = '0';
pFormat++;
}
/* Parse width */
while ((*pFormat >= '0') && (*pFormat <= '9')) {
width = (width*10) + *pFormat-'0';
pFormat++;
}
/* Check if there is enough space */
if (size + width > length) {
width = length - size;
}
/* Parse type */
switch (*pFormat) {
case 'd':
case 'i': num = PutSignedInt(pStr, fill, width, va_arg(ap, signed int)); break;
case 'u': num = PutUnsignedInt(pStr, fill, width, va_arg(ap, unsigned int)); break;
case 'x': num = PutHexa(pStr, fill, width, 0, va_arg(ap, unsigned int)); break;
case 'X': num = PutHexa(pStr, fill, width, 1, va_arg(ap, unsigned int)); break;
case 's': num = PutString(pStr, va_arg(ap, char *)); break;
case 'c': num = PutChar(pStr, va_arg(ap, unsigned int)); break;
default:
return EOF;
}
pFormat++;
pStr += num;
size += num;
}
}
/* NULL-terminated (final \0 is not counted) */
if (size < length) {
*pStr = 0;
}
else {
*(--pStr) = 0;
size--;
}
return size;
}
/**
* @brief Stores the result of a formatted string into another string. Format
* arguments are given in a va_list instance.
*
* @param pStr Destination string.
* @param length Length of Destination string.
* @param pFormat Format string.
* @param ... Other arguments
*
* @return The number of characters written.
*/
signed int snprintf(char *pString, size_t length, const char *pFormat, ...)
{
va_list ap;
signed int rc;
va_start(ap, pFormat);
rc = vsnprintf(pString, length, pFormat, ap);
va_end(ap);
return rc;
}
/**
* @brief Stores the result of a formatted string into another string. Format
* arguments are given in a va_list instance.
*
* @param pString Destination string.
* @param length Length of Destination string.
* @param pFormat Format string.
* @param ap Argument list.
*
* @return The number of characters written.
*/
signed int vsprintf(char *pString, const char *pFormat, va_list ap)
{
return vsnprintf(pString, MAX_STRING_SIZE, pFormat, ap);
}
/**
* @brief Outputs a formatted string on the given stream. Format arguments are given
* in a va_list instance.
*
* @param pStream Output stream.
* @param pFormat Format string
* @param ap Argument list.
*/
signed int vfprintf(FILE *pStream, const char *pFormat, va_list ap)
{
char pStr[MAX_STRING_SIZE];
char pError[] = "stdio.c: increase MAX_STRING_SIZE\n\r";
/* Write formatted string in buffer */
if (vsprintf(pStr, pFormat, ap) >= MAX_STRING_SIZE) {
fputs(pError, stderr);
while (1); /* Increase MAX_STRING_SIZE */
}
/* Display string */
return fputs(pStr, pStream);
}
/**
* @brief Outputs a formatted string on the DBGU stream. Format arguments are given
* in a va_list instance.
*
* @param pFormat Format string.
* @param ap Argument list.
*/
signed int vprintf(const char *pFormat, va_list ap)
{
return vfprintf(stdout, pFormat, ap);
}
/**
* @brief Outputs a formatted string on the given stream, using a variable
* number of arguments.
*
* @param pStream Output stream.
* @param pFormat Format string.
*/
signed int fprintf(FILE *pStream, const char *pFormat, ...)
{
va_list ap;
signed int result;
/* Forward call to vfprintf */
va_start(ap, pFormat);
result = vfprintf(pStream, pFormat, ap);
va_end(ap);
return result;
}
/**
* @brief Outputs a formatted string on the DBGU stream, using a variable number of
* arguments.
*
* @param pFormat Format string.
*/
signed int printf(const char *pFormat, ...)
{
va_list ap;
signed int result;
/* Forward call to vprintf */
va_start(ap, pFormat);
result = vprintf(pFormat, ap);
va_end(ap);
return result;
}
/**
* @brief Writes a formatted string inside another string.
*
* @param pStr torage string.
* @param pFormat Format string.
*/
signed int sprintf(char *pStr, const char *pFormat, ...)
{
va_list ap;
signed int result;
// Forward call to vsprintf
va_start(ap, pFormat);
result = vsprintf(pStr, pFormat, ap);
va_end(ap);
return result;
}
/**
* @brief Outputs a string on stdout.
*
* @param pStr String to output.
*/
signed int puts(const char *pStr)
{
return fputs(pStr, stdout);
}
/**
* @brief Implementation of fputc using the DBGU as the standard output. Required
* for printf().
*
* @param c Character to write.
* @param pStream Output stream.
* @param The character written if successful, or -1 if the output stream is
* not stdout or stderr.
*/
signed int fputc(signed int c, FILE *pStream)
{
if ((pStream == stdout) || (pStream == stderr)) {
PrintChar(c);
return c;
}
else {
return EOF;
}
}