From 26f12903dab2fafeaaefb02349763618ce96d070 Mon Sep 17 00:00:00 2001 From: Paul Selkirk Date: Mon, 26 Oct 2015 15:18:58 -0400 Subject: Based on user/ft/stm32-dev-bridge, without the project-specific build directories (and duplicated code). --- libc/printf.c | 412 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 412 insertions(+) create mode 100644 libc/printf.c (limited to 'libc') diff --git a/libc/printf.c b/libc/printf.c new file mode 100644 index 0000000..78f210a --- /dev/null +++ b/libc/printf.c @@ -0,0 +1,412 @@ +/***************************************************************************** +Stripped-down printf() +Chris Giese http://my.execpc.com/~geezer +Release date: Dec 12, 2003 +This code is public domain (no copyright). +You can do whatever you want with it. + +Revised Dec 12, 2003 +- fixed vsprintf() and sprintf() in test code + +Revised Jan 28, 2002 +- changes to make characters 0x80-0xFF display properly + +Revised June 10, 2001 +- changes to make vsprintf() terminate string with '\0' + +Revised May 12, 2000 +- math in DO_NUM is now unsigned, as it should be +- %0 flag (pad left with zeroes) now works +- actually did some TESTING, maybe fixed some other bugs + +%[flag][width][.prec][mod][conv] +flag: - left justify, pad right w/ blanks DONE + 0 pad left w/ 0 for numerics DONE + + always print sign, + or - no + ' ' (blank) no + # (???) no + +width: (field width) DONE + +prec: (precision) no + +conv: d,i decimal int DONE + u decimal unsigned DONE + o octal DONE + x,X hex DONE + f,e,g,E,G float no + c char DONE + s string DONE + p ptr DONE + +mod: N near ptr DONE + F far ptr no + h short (16-bit) int DONE + l long (32-bit) int DONE + L long long (64-bit) int no +*****************************************************************************/ +#include /* strlen() */ +#include /* stdout, putchar(), fputs() (but not printf() :) */ + +#if 1 +#include /* va_list, va_start(), va_arg(), va_end() */ +#else +/* home-brew STDARG.H, also public-domain: */ + +/* Assume: width of stack == width of int. Don't use sizeof(char *) or +other pointer because sizeof(char *)==4 for LARGE-model 16-bit code. +Assume: width is a power of 2 */ +#define STACK_WIDTH sizeof(int) + +/* Round up object width so it's an even multiple of STACK_WIDTH. +Using & for division here, so STACK_WIDTH must be a power of 2. */ +#define TYPE_WIDTH(TYPE) \ + ((sizeof(TYPE) + STACK_WIDTH - 1) & ~(STACK_WIDTH - 1)) + +/* point the va_list pointer to LASTARG, +then advance beyond it to the first variable arg */ +#define va_start(PTR, LASTARG) \ + PTR = (va_list)((char *)&(LASTARG) + TYPE_WIDTH(LASTARG)) + +#define va_end(PTR) /* nothing */ + +/* Increment the va_list pointer, then return +(evaluate to, actually) the previous value of the pointer. +WHEEE! At last; a valid use for the C comma operator! */ +#define va_arg(PTR, TYPE) ( \ + (char *)(PTR) += TYPE_WIDTH(TYPE) \ + , \ + *((TYPE *)((char *)(PTR) - TYPE_WIDTH(TYPE))) \ + ) +/* Every other compiler/libc seems to be using 'void *', so... +(I _was_ using 'unsigned char *') */ +typedef void *va_list; + +#endif + +/* flags used in processing format string */ +#define PR_LJ 0x01 /* left justify */ +#define PR_CA 0x02 /* use A-F instead of a-f for hex */ +#define PR_SG 0x04 /* signed numeric conversion (%d vs. %u) */ +#define PR_32 0x08 /* long (32-bit) numeric conversion */ +#define PR_16 0x10 /* short (16-bit) numeric conversion */ +#define PR_WS 0x20 /* PR_SG set and num was < 0 */ +#define PR_LZ 0x40 /* pad left with '0' instead of ' ' */ +#define PR_FP 0x80 /* pointers are far */ +#if 0 +/* largest number handled is 2^32-1, lowest radix handled is 8. +2^32-1 in base 8 has 11 digits (add 5 for trailing NUL and for slop) */ +#define PR_BUFLEN 16 +#else +/* largest number handled is 2^64-1, lowest radix handled is 8. +2^64-1 in base 8 has 22 digits (add 2 for trailing NUL and for slop) */ +#define PR_BUFLEN 24 +#endif + +typedef int (*fnptr_t)(unsigned c, void **helper); +/***************************************************************************** +name: do_printf +action: minimal subfunction for ?printf, calls function + 'fn' with arg 'ptr' for each character to be output +returns:total number of characters output +*****************************************************************************/ +int do_printf(const char *fmt, va_list args, fnptr_t fn, void *ptr) +{ + unsigned flags, actual_wd, count, given_wd; + unsigned char *where, buf[PR_BUFLEN]; + unsigned char state, radix; + long num; + + state = flags = count = given_wd = 0; +/* begin scanning format specifier list */ + for(; *fmt; fmt++) + { + switch(state) + { +/* STATE 0: AWAITING % */ + case 0: + if(*fmt != '%') /* not %... */ + { + fn(*fmt, &ptr); /* ...just echo it */ + count++; + break; + } +/* found %, get next char and advance state to check if next char is a flag */ + state++; + fmt++; + /* FALL THROUGH */ +/* STATE 1: AWAITING FLAGS (%-0) */ + case 1: + if(*fmt == '%') /* %% */ + { + fn(*fmt, &ptr); + count++; + state = flags = given_wd = 0; + break; + } + if(*fmt == '-') + { + if(flags & PR_LJ)/* %-- is illegal */ + state = flags = given_wd = 0; + else + flags |= PR_LJ; + break; + } +/* not a flag char: advance state to check if it's field width */ + state++; +/* check now for '%0...' */ + if(*fmt == '0') + { + flags |= PR_LZ; + fmt++; + } + /* FALL THROUGH */ +/* STATE 2: AWAITING (NUMERIC) FIELD WIDTH */ + case 2: + if(*fmt >= '0' && *fmt <= '9') + { + given_wd = 10 * given_wd + + (*fmt - '0'); + break; + } +/* not field width: advance state to check if it's a modifier */ + state++; + /* FALL THROUGH */ +/* STATE 3: AWAITING MODIFIER CHARS (FNlh) */ + case 3: + if(*fmt == 'F') + { + flags |= PR_FP; + break; + } + if(*fmt == 'N') + break; + if(*fmt == 'l') + { + flags |= PR_32; + break; + } + if(*fmt == 'h') + { + flags |= PR_16; + break; + } +/* not modifier: advance state to check if it's a conversion char */ + state++; + /* FALL THROUGH */ +/* STATE 4: AWAITING CONVERSION CHARS (Xxpndiuocs) */ + case 4: + where = buf + PR_BUFLEN - 1; + *where = '\0'; + switch(*fmt) + { + case 'X': + flags |= PR_CA; + /* FALL THROUGH */ +/* xxx - far pointers (%Fp, %Fn) not yet supported */ + case 'x': + case 'p': + case 'n': + radix = 16; + goto DO_NUM; + case 'd': + case 'i': + flags |= PR_SG; + /* FALL THROUGH */ + case 'u': + radix = 10; + goto DO_NUM; + case 'o': + radix = 8; +/* load the value to be printed. l=long=32 bits: */ +DO_NUM: if(flags & PR_32) + num = va_arg(args, unsigned long); +/* h=short=16 bits (signed or unsigned) */ + else if(flags & PR_16) + { + if(flags & PR_SG) + num = va_arg(args, short); + else + num = va_arg(args, unsigned short); + } +/* no h nor l: sizeof(int) bits (signed or unsigned) */ + else + { + if(flags & PR_SG) + num = va_arg(args, int); + else + num = va_arg(args, unsigned int); + } +/* take care of sign */ + if(flags & PR_SG) + { + if(num < 0) + { + flags |= PR_WS; + num = -num; + } + } +/* convert binary to octal/decimal/hex ASCII +OK, I found my mistake. The math here is _always_ unsigned */ + do + { + unsigned long temp; + + temp = (unsigned long)num % radix; + where--; + if(temp < 10) + *where = temp + '0'; + else if(flags & PR_CA) + *where = temp - 10 + 'A'; + else + *where = temp - 10 + 'a'; + num = (unsigned long)num / radix; + } + while(num != 0); + goto EMIT; + case 'c': +/* disallow pad-left-with-zeroes for %c */ + flags &= ~PR_LZ; + where--; + *where = (unsigned char)va_arg(args, + unsigned char); + actual_wd = 1; + goto EMIT2; + case 's': +/* disallow pad-left-with-zeroes for %s */ + flags &= ~PR_LZ; + where = va_arg(args, unsigned char *); +EMIT: + actual_wd = strlen(where); + if(flags & PR_WS) + actual_wd++; +/* if we pad left with ZEROES, do the sign now */ + if((flags & (PR_WS | PR_LZ)) == + (PR_WS | PR_LZ)) + { + fn('-', &ptr); + count++; + } +/* pad on left with spaces or zeroes (for right justify) */ +EMIT2: if((flags & PR_LJ) == 0) + { + while(given_wd > actual_wd) + { + fn(flags & PR_LZ ? + '0' : ' ', &ptr); + count++; + given_wd--; + } + } +/* if we pad left with SPACES, do the sign now */ + if((flags & (PR_WS | PR_LZ)) == PR_WS) + { + fn('-', &ptr); + count++; + } +/* emit string/char/converted number */ + while(*where != '\0') + { + fn(*where++, &ptr); + count++; + } +/* pad on right with spaces (for left justify) */ + if(given_wd < actual_wd) + given_wd = 0; + else given_wd -= actual_wd; + for(; given_wd; given_wd--) + { + fn(' ', &ptr); + count++; + } + break; + default: + break; + } + default: + state = flags = given_wd = 0; + break; + } + } + return count; +} +#if 1 /* testing */ +/***************************************************************************** +SPRINTF +*****************************************************************************/ +static int vsprintf_help(unsigned c, void **ptr) +{ + char *dst; + + dst = *ptr; + *dst++ = (char)c; + *ptr = dst; + return 0 ; +} +/***************************************************************************** +*****************************************************************************/ +int vsprintf(char *buf, const char *fmt, va_list args) +{ + int rv; + + rv = do_printf(fmt, args, vsprintf_help, (void *)buf); + buf[rv] = '\0'; + return rv; +} +/***************************************************************************** +*****************************************************************************/ +int sprintf(char *buf, const char *fmt, ...) +{ + va_list args; + int rv; + + va_start(args, fmt); + rv = vsprintf(buf, fmt, args); + va_end(args); + return rv; +} +/***************************************************************************** +PRINTF +You must write your own putchar() +*****************************************************************************/ +int vprintf_help(unsigned c, void **ptr) +{ + putchar(c); + return 0 ; +} +/***************************************************************************** +*****************************************************************************/ +int vprintf(const char *fmt, va_list args) +{ + return do_printf(fmt, args, vprintf_help, NULL); +} +/***************************************************************************** +*****************************************************************************/ +int printf(const char *fmt, ...) +{ + va_list args; + int rv; + + va_start(args, fmt); + rv = vprintf(fmt, args); + va_end(args); + return rv; +} +#endif +#if 0 +/***************************************************************************** +*****************************************************************************/ +int main(void) +{ + char buf[64]; + + sprintf(buf, "%lu score and %i years ago...\n", 4L, -7); + fputs(buf, stdout); /* puts() adds newline */ + + sprintf(buf, "-1L == 0x%lX == octal %lo\n", -1L, -1L); + fputs(buf, stdout); /* puts() adds newline */ + + printf("<%-8s> and <%8s> justified strings\n", "left", "right"); + return 0; +} +#endif -- cgit v1.2.3