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/*
 * Copyright (C) 2001-2004 Jakub Jermar
 * Copyright (C) 2006 Josef Cejka
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup generic 
 * @{
 */
/**
 * @file
 * @brief   Printing functions.
 */

#include <printf/printf_core.h>
#include <putchar.h>
#include <print.h>
#include <synch/spinlock.h>
#include <arch/arg.h>
#include <arch/asm.h>

#include <arch.h>

SPINLOCK_INITIALIZE(printflock);            /**< printf spinlock */

#define __PRINTF_FLAG_PREFIX        0x00000001  /**< show prefixes 0x or 0*/
#define __PRINTF_FLAG_SIGNED        0x00000002  /**< signed / unsigned number */
#define __PRINTF_FLAG_ZEROPADDED    0x00000004  /**< print leading zeroes */
#define __PRINTF_FLAG_LEFTALIGNED   0x00000010  /**< align to left */
#define __PRINTF_FLAG_SHOWPLUS      0x00000020  /**< always show + sign */
#define __PRINTF_FLAG_SPACESIGN     0x00000040  /**< print space instead of plus */
#define __PRINTF_FLAG_BIGCHARS      0x00000080  /**< show big characters */
#define __PRINTF_FLAG_NEGATIVE      0x00000100  /**< number has - sign */

#define PRINT_NUMBER_BUFFER_SIZE    (64+5)      /**< Buffer big enought for 64 bit number
                             * printed in base 2, sign, prefix and
                             * 0 to terminate string.. (last one is only for better testing 
                             * end of buffer by zero-filling subroutine)*/

/** Enumeration of possible arguments types.
 */
typedef enum {
    PrintfQualifierByte = 0,
    PrintfQualifierShort,
    PrintfQualifierInt,
    PrintfQualifierLong,
    PrintfQualifierLongLong,
    PrintfQualifierNative,
    PrintfQualifierPointer
} qualifier_t;

static char digits_small[] = "0123456789abcdef";    /**< Small hexadecimal characters */
static char digits_big[] = "0123456789ABCDEF";  /**< Big hexadecimal characters */

/** Checks c for a digit.
 * @param c One character.
 * @return nonzero if c is from interval '0 to '9'.
 */
static inline int isdigit(int c)
{
    return ((c >= '0' )&&( c <= '9'));
}

/** Compute length of given zero terminated string.
 * @param str Pointer to valid string.
 * @return string length without trailing zero.
 */
static unative_t strlen(const char *str) 
{
    unative_t counter = 0;

    while (str[counter] != 0) {
        counter++;
    }

    return counter;
}

/** Print count chars from buffer without adding newline
 * @param buf Buffer with size at least count bytes - NULL pointer NOT allowed!
 * @param count 
 * @param ps output method and its data
 * @return number of printed characters
 */
static int printf_putnchars(const char * buf, size_t count, struct printf_spec *ps)
{
    return ps->write((void *)buf, count, ps->data);
}

/** Print string without added newline
 * @param str string to print
 * @param ps write function specification and support data
 * @return number of printed characters
 */
static int printf_putstr(const char * str, struct printf_spec *ps)
{
    size_t count;
    
    if (str == NULL) {
        return printf_putnchars("(NULL)", 6, ps);
    }

    count = strlen(str);

    return ps->write((void *) str, count, ps->data);
}

/** Print one character to output
 * @param c one character
 * @param ps output method
 * @return number of printed characters
 */
static int printf_putchar(int c, struct printf_spec *ps)
{
    unsigned char ch = c;
    
    return ps->write((void *) &ch, 1, ps->data);
}

/** Print one formatted character
 * @param c character to print
 * @param width 
 * @param flags
 * @return number of printed characters, negative value on fail
 */
static int print_char(char c, int width, uint64_t flags, struct printf_spec *ps)
{
    int counter = 0;
    
    if (!(flags & __PRINTF_FLAG_LEFTALIGNED)) {
        while (--width > 0) {   /* one space is consumed by character itself hence predecrement */
            if (printf_putchar(' ', ps) > 0)    
                ++counter;
        }
    }
    
    if (printf_putchar(c, ps) > 0)
        counter++;

    while (--width > 0) { /* one space is consumed by character itself hence predecrement */
        if (printf_putchar(' ', ps) > 0)
            ++counter;
    }
    
    return ++counter;
}

/** Print one string
 * @param s string
 * @param width 
 * @param precision
 * @param flags
 * @return number of printed characters or negative value on fail
 */
                        
static int print_string(char *s, int width, int precision, uint64_t flags, struct printf_spec *ps)
{
    int counter = 0;
    size_t size;
    int retval;

    if (s == NULL) {
        return printf_putstr("(NULL)", ps);
    }
    
    size = strlen(s);

    /* print leading spaces */

    if (precision == 0) 
        precision = size;

    width -= precision;
    
    if (!(flags & __PRINTF_FLAG_LEFTALIGNED)) {
        while (width-- > 0) {   
            if (printf_putchar(' ', ps) == 1)   
                counter++;
        }
    }

    while (precision > size) {
        precision--;
        if (printf_putchar(' ', ps) == 1)   
            ++counter;
    }
    
    if ((retval = printf_putnchars(s, precision, ps)) < 0) {
        return -counter;
    }
    counter += retval;  

    while (width-- > 0) {
        if (printf_putchar(' ', ps) == 1)   
            ++counter;
    }
    
    return counter;
}


/** Print number in given base
 *
 * Print significant digits of a number in given
 * base.
 *
 * @param num  Number to print.
 * @param width
 * @param precision
 * @param base Base to print the number in (should
 *             be in range 2 .. 16).
 * @param flags output modifiers
 * @return number of written characters or EOF
 *
 */
static int print_number(uint64_t num, int width, int precision, int base , uint64_t flags, struct printf_spec *ps)
{
    char *digits = digits_small;
    char d[PRINT_NUMBER_BUFFER_SIZE];   /* this is good enough even for base == 2, prefix and sign */
    char *ptr = &d[PRINT_NUMBER_BUFFER_SIZE - 1];
    int size = 0; /* size of number with all prefixes and signs */
    int number_size; /* size of plain number */
    char sgn;
    int retval;
    int counter = 0;
    
    if (flags & __PRINTF_FLAG_BIGCHARS) 
        digits = digits_big;    
    
    *ptr-- = 0; /* Put zero at end of string */

    if (num == 0) {
        *ptr-- = '0';
        size++;
    } else {
        do {
            *ptr-- = digits[num % base];
            size++;
        } while (num /= base);
    }
    
    number_size = size;

    /* Collect sum of all prefixes/signs/... to calculate padding and leading zeroes */
    if (flags & __PRINTF_FLAG_PREFIX) {
        switch(base) {
        case 2: /* Binary formating is not standard, but usefull */
            size += 2;
            break;
        case 8:
            size++;
            break;
        case 16:
            size += 2;
            break;
        }
    }

    sgn = 0;
    if (flags & __PRINTF_FLAG_SIGNED) {
        if (flags & __PRINTF_FLAG_NEGATIVE) {
            sgn = '-';
            size++;
        } else if (flags & __PRINTF_FLAG_SHOWPLUS) {
                sgn = '+';
                size++;
            } else if (flags & __PRINTF_FLAG_SPACESIGN) {
                    sgn = ' ';
                    size++;
                }
    }

    if (flags & __PRINTF_FLAG_LEFTALIGNED) {
        flags &= ~__PRINTF_FLAG_ZEROPADDED;
    }

    /* if number is leftaligned or precision is specified then zeropadding is ignored */
    if (flags & __PRINTF_FLAG_ZEROPADDED) {
        if ((precision == 0) && (width > size)) {
            precision = width - size + number_size;
        }
    }

    /* print leading spaces */
    if (number_size > precision) /* We must print whole number not only a part */
        precision = number_size;

    width -= precision + size - number_size;
    
    if (!(flags & __PRINTF_FLAG_LEFTALIGNED)) {
        while (width-- > 0) {   
            if (printf_putchar(' ', ps) == 1)   
                counter++;
        }
    }
    
    
    /* print sign */
    if (sgn) {
        if (printf_putchar(sgn, ps) == 1)
            counter++;
    }
    
    /* print prefix */
    
    if (flags & __PRINTF_FLAG_PREFIX) {
        switch(base) {
        case 2: /* Binary formating is not standard, but usefull */
            if (printf_putchar('0', ps) == 1)
                counter++;
            if (flags & __PRINTF_FLAG_BIGCHARS) {
                if (printf_putchar('B', ps) == 1)
                    counter++;
            } else {
                if (printf_putchar('b', ps) == 1)
                    counter++;
            }
            break;
        case 8:
            if (printf_putchar('o', ps) == 1)
                counter++;
            break;
        case 16:
            if (printf_putchar('0', ps) == 1)
                counter++;
            if (flags & __PRINTF_FLAG_BIGCHARS) {
                if (printf_putchar('X', ps) == 1)
                    counter++;
            } else {
                if (printf_putchar('x', ps) == 1)
                    counter++;
            }
            break;
        }
    }

    /* print leading zeroes */
    precision -= number_size;
    while (precision-- > 0) {   
        if (printf_putchar('0', ps) == 1)
            counter++;
    }

    
    /* print number itself */

    if ((retval = printf_putstr(++ptr, ps)) > 0) {
        counter += retval;
    }
    
    /* print ending spaces */
    
    while (width-- > 0) {   
        if (printf_putchar(' ', ps) == 1)   
            counter++;
    }

    return counter;
}


/** Print formatted string.
 *
 * Print string formatted according to the fmt parameter
 * and variadic arguments. Each formatting directive
 * must have the following form:
 * 
 *  \% [ FLAGS ] [ WIDTH ] [ .PRECISION ] [ TYPE ] CONVERSION
 *
 * FLAGS:@n
 *  - "#" Force to print prefix.
 *  For conversion \%o the prefix is 0, for \%x and \%X prefixes are 0x and 0X
 *  and for conversion \%b the prefix is 0b.
 *
 *  - "-"   Align to left.
 *
 *  - "+"   Print positive sign just as negative.
 *
 *  - " "   If the printed number is positive and "+" flag is not set, print space in
 *  place of sign.
 *
 *  - "0"    Print 0 as padding instead of spaces. Zeroes are placed between sign and the
 *  rest of the number. This flag is ignored if "-" flag is specified.
 * 
 * WIDTH:@n
 *  - Specify minimal width of printed argument. If it is bigger, width is ignored.
 * If width is specified with a "*" character instead of number, width is taken from
 * parameter list. And integer parameter is expected before parameter for processed
 * conversion specification. If this value is negative its absolute value is taken
 * and the "-" flag is set.
 *
 * PRECISION:@n
 *  - Value precision. For numbers it specifies minimum valid numbers.
 * Smaller numbers are printed with leading zeroes. Bigger numbers are not affected.
 * Strings with more than precision characters are cut off.
 * Just as with width, an "*" can be used used instead of a number.
 * An integer value is then expected in parameters. When both width and precision
 * are specified using "*", the first parameter is used for width and the second one
 * for precision.
 * 
 * TYPE:@n
 *  - "hh"  Signed or unsigned char.@n
 *  - "h"   Signed or usigned short.@n
 *  - ""    Signed or usigned int (default value).@n
 *  - "l"   Signed or usigned long int.@n
 *  - "ll"  Signed or usigned long long int.@n
 *  - "z"   unative_t (non-standard extension).@n
 * 
 * 
 * CONVERSION:@n
 *  - % Print percentile character itself.
 *
 *  - c Print single character.
 *
 *  - s Print zero terminated string. If a NULL value is passed as value, "(NULL)" is printed instead.
 * 
 *  - P, p  Print value of a pointer. Void * value is expected and it is printed in hexadecimal notation with prefix
 *  (as with \%#X or \%#x for 32bit or \%#X / \%#x for 64bit long pointers).
 *
 *  - b Print value as unsigned binary number. Prefix is not printed by default. (Nonstandard extension.)
 * 
 *  - o Print value as unsigned octal number. Prefix is not printed by default. 
 *
 *  - d,i   Print signed decimal number. There is no difference between d and i conversion.
 *
 *  - u Print unsigned decimal number.
 *
 *  - X, x  Print hexadecimal number with upper- or lower-case. Prefix is not printed by default.
 * 
 * All other characters from fmt except the formatting directives
 * are printed in verbatim.
 *
 * @param fmt Formatting NULL terminated string.
 * @return Number of printed characters or negative value on failure.
 */
int printf_core(const char *fmt, struct printf_spec *ps, va_list ap)
{
    int irqpri;
    int i = 0, j = 0; /**< i is index of currently processed char from fmt, j is index to the first not printed nonformating character */
    int end;
    int counter; /**< counter of printed characters */
    int retval; /**< used to store return values from called functions */
    char c;
    qualifier_t qualifier;  /* type of argument */
    int base;   /**< base in which will be parameter (numbers only) printed */
    uint64_t number; /**< argument value */
    size_t  size; /**< byte size of integer parameter */
    int width, precision;
    uint64_t flags;
    
    counter = 0;
    
    irqpri = interrupts_disable();
    spinlock_lock(&printflock);

    while ((c = fmt[i])) {
        /* control character */
        if (c == '%' ) { 
            /* print common characters if any processed */  
            if (i > j) {
                if ((retval = printf_putnchars(&fmt[j], (size_t)(i - j), ps)) < 0) { /* error */
                    counter = -counter;
                    goto out;
                }
                counter += retval;
            }
        
            j = i;
            /* parse modifiers */
            flags = 0;
            end = 0;
            
            do {
                ++i;
                switch (c = fmt[i]) {
                case '#': flags |= __PRINTF_FLAG_PREFIX; break;
                case '-': flags |= __PRINTF_FLAG_LEFTALIGNED; break;
                case '+': flags |= __PRINTF_FLAG_SHOWPLUS; break;
                case ' ': flags |= __PRINTF_FLAG_SPACESIGN; break;
                case '0': flags |= __PRINTF_FLAG_ZEROPADDED; break;
                default: end = 1;
                };  
                
            } while (end == 0); 
            
            /* width & '*' operator */
            width = 0;
            if (isdigit(fmt[i])) {
                while (isdigit(fmt[i])) {
                    width *= 10;
                    width += fmt[i++] - '0';
                }
            } else if (fmt[i] == '*') {
                /* get width value from argument list*/
                i++;
                width = (int)va_arg(ap, int);
                if (width < 0) {
                    /* negative width means to set '-' flag */
                    width *= -1;
                    flags |= __PRINTF_FLAG_LEFTALIGNED;
                }
            }
            
            /* precision and '*' operator */    
            precision = 0;
            if (fmt[i] == '.') {
                ++i;
                if (isdigit(fmt[i])) {
                    while (isdigit(fmt[i])) {
                        precision *= 10;
                        precision += fmt[i++] - '0';
                    }
                } else if (fmt[i] == '*') {
                    /* get precision value from argument list*/
                    i++;
                    precision = (int)va_arg(ap, int);
                    if (precision < 0) {
                        /* negative precision means to ignore it */
                        precision = 0;
                    }
                }
            }

            switch (fmt[i++]) {
            /** TODO: unimplemented qualifiers:
             * t ptrdiff_t - ISO C 99
             */
            case 'h':   /* char or short */
                qualifier = PrintfQualifierShort;
                if (fmt[i] == 'h') {
                    i++;
                    qualifier = PrintfQualifierByte;
                }
                break;
            case 'l':   /* long or long long*/
                qualifier = PrintfQualifierLong;
                if (fmt[i] == 'l') {
                    i++;
                    qualifier = PrintfQualifierLongLong;
                }
                break;
            case 'z':   /* unative_t */
                qualifier = PrintfQualifierNative;
                break;
            default:
                qualifier = PrintfQualifierInt; /* default type */
                --i;
            }   
            
            base = 10;

            switch (c = fmt[i]) {

            /*
            * String and character conversions.
            */
            case 's':
                if ((retval = print_string(va_arg(ap, char*), width, precision, flags, ps)) < 0) {
                    counter = -counter;
                    goto out;
                };

                counter += retval;
                j = i + 1; 
                goto next_char;
            case 'c':
                c = va_arg(ap, unsigned int);
                if ((retval = print_char(c, width, flags, ps)) < 0) {
                    counter = -counter;
                    goto out;
                };
                    
                counter += retval;
                j = i + 1;
                goto next_char;

            /* 
             * Integer values
             */
            case 'P': /* pointer */
                    flags |= __PRINTF_FLAG_BIGCHARS;
            case 'p':
                flags |= __PRINTF_FLAG_PREFIX;
                base = 16;
                qualifier = PrintfQualifierPointer;
                break;  
            case 'b': 
                base = 2;
                break;
            case 'o':
                base = 8;
                break;
            case 'd':
            case 'i':
                flags |= __PRINTF_FLAG_SIGNED;  
            case 'u':
                break;
            case 'X':
                flags |= __PRINTF_FLAG_BIGCHARS;
            case 'x':
                base = 16;
                break;
            /* percentile itself */
            case '%': 
                j = i;
                goto next_char;
            /*
             * Bad formatting.
             */
            default:
                /* Unknown format
                 * now, j is index of '%' so we will
                 * print whole bad format sequence
                 */
                goto next_char;     
            }
        
        
        /* Print integers */
            /* print number */
            switch (qualifier) {
            case PrintfQualifierByte:
                size = sizeof(unsigned char);
                number = (uint64_t)va_arg(ap, unsigned int);
                break;
            case PrintfQualifierShort:
                size = sizeof(unsigned short);
                number = (uint64_t)va_arg(ap, unsigned int);
                break;
            case PrintfQualifierInt:
                size = sizeof(unsigned int);
                number = (uint64_t)va_arg(ap, unsigned int);
                break;
            case PrintfQualifierLong:
                size = sizeof(unsigned long);
                number = (uint64_t)va_arg(ap, unsigned long);
                break;
            case PrintfQualifierLongLong:
                size = sizeof(unsigned long long);
                number = (uint64_t)va_arg(ap, unsigned long long);
                break;
            case PrintfQualifierPointer:
                size = sizeof(void *);
                number = (uint64_t)(unsigned long)va_arg(ap, void *);
                break;
            case PrintfQualifierNative:
                size = sizeof(unative_t);
                number = (uint64_t)va_arg(ap, unative_t);
                break;
            default: /* Unknown qualifier */
                counter = -counter;
                goto out;
            }
            
            if (flags & __PRINTF_FLAG_SIGNED) {
                if (number & (0x1 << (size*8 - 1))) {
                    flags |= __PRINTF_FLAG_NEGATIVE;
                
                    if (size == sizeof(uint64_t)) {
                        number = -((int64_t)number);
                    } else {
                        number = ~number;
                        number &= (~((0xFFFFFFFFFFFFFFFFll) <<  (size * 8)));
                        number++;
                    }
                }
            }

            if ((retval = print_number(number, width, precision, base, flags, ps)) < 0) {
                counter = -counter;
                goto out;
            };

            counter += retval;
            j = i + 1;
        }   
next_char:
            
        ++i;
    }
    
    if (i > j) {
        if ((retval = printf_putnchars(&fmt[j], (unative_t)(i - j), ps)) < 0) { /* error */
            counter = -counter;
            goto out;
            
        }
        counter += retval;
    }

out:
    spinlock_unlock(&printflock);
    interrupts_restore(irqpri);
    
    return counter;
}

/** @}
 */