--- /dev/null
+/*
+ * This code was originally part of klibc-0.103.
+ * It was adapted by David Hovemeyer <daveho@cs.umd.edu>
+ * for use in GeekOS (http://geekos.sourceforge.net).
+ *
+ * For information/source for klibc, visit
+ * http://www.kernel.org/pub/linux/libs/klibc/
+ * http://www.zytor.com/mailman/listinfo/klibc/
+ * http://www.zytor.com/cvsweb.cgi/klibc/
+ *
+ * Modifications are marked with "DHH".
+ * Summary of modifications:
+ *
+ * 1. Use struct Output_Sink to emit formatted output, rather than a
+ * character buffer, to allow output polymorphism.
+ *
+ * 2. Buffer generated numbers so that all output is generated in order.
+ *
+ * 3. Don't use long long types: unsigned long is largest
+ * supported type. Arithmetic on 64 bit types requires runtime support
+ * (at least on x86).
+ *
+ * See the file LICENSE-klibc for license information.
+ */
+
+/*
+ * vsnprintf.c
+ *
+ * vsnprintf(), from which the rest of the printf()
+ * family is built
+ */
+
+#include <stdarg.h>
+#include <stddef.h>
+#include <geekos/string.h>
+#include <limits.h>
+#include <geekos/fmtout.h> /* DHH: for struct Output_Sink */
+
+/*
+ * DHH: Hack, long long arithmetic requires runtime support.
+ * Use unsigned long as greatest unsigned integer supported.
+ */
+typedef long intmax_t;
+typedef unsigned long uintmax_t;
+typedef unsigned long uintptr_t;
+
+/* DHH */
+#define ASSERT(exp) \
+do { if (!(exp)) while(1); } while (0)
+
+enum flags {
+ FL_ZERO = 0x01, /* Zero modifier */
+ FL_MINUS = 0x02, /* Minus modifier */
+ FL_PLUS = 0x04, /* Plus modifier */
+ FL_TICK = 0x08, /* ' modifier */
+ FL_SPACE = 0x10, /* Space modifier */
+ FL_HASH = 0x20, /* # modifier */
+ FL_SIGNED = 0x40, /* Number is signed */
+ FL_UPPER = 0x80 /* Upper case digits */
+};
+
+/* These may have to be adjusted on certain implementations */
+enum ranks {
+ rank_char = -2,
+ rank_short = -1,
+ rank_int = 0,
+ rank_long = 1,
+#if 0
+ rank_longlong = 2,
+#endif
+};
+
+#define MIN_RANK rank_char
+#define MAX_RANK rank_long
+
+#define INTMAX_RANK rank_long
+#define SIZE_T_RANK rank_long
+#define PTRDIFF_T_RANK rank_long
+
+/* DHH */
+#define EMIT(x) do { (q)->Emit((q), (x)); } while (0)
+
+/*
+ * DHH - As a hack, we buffer this many digits when generating
+ * a number. Because this code originally was an implementation
+ * of vnsprintf(), it generated some digits backwards in a buffer.
+ * Obviously we can't do this when emitting output directly
+ * to the console or a file. So, we buffer the generated digits
+ * and then emit them in order.
+ *
+ * This value should be adequate to emit values up to 2^32-1 in
+ * bases 2 or greater, including tick marks.
+ */
+#define NDIGITS_MAX 43
+
+static size_t
+format_int(struct Output_Sink *q, uintmax_t val, enum flags flags,
+ int base, int width, int prec)
+{
+ char *qq;
+ size_t o = 0, oo;
+ static const char lcdigits[] = "0123456789abcdef";
+ static const char ucdigits[] = "0123456789ABCDEF";
+ const char *digits;
+ uintmax_t tmpval;
+ int minus = 0;
+ int ndigits = 0, nchars;
+ int tickskip, b4tick;
+ char digit_buffer[NDIGITS_MAX]; /* DHH */
+ size_t ndigits_save; /* DHH */
+
+ /* Select type of digits */
+ digits = (flags & FL_UPPER) ? ucdigits : lcdigits;
+
+ /* If signed, separate out the minus */
+ if ( flags & FL_SIGNED && (intmax_t)val < 0 ) {
+ minus = 1;
+ val = (uintmax_t)(-(intmax_t)val);
+ }
+
+ /* Count the number of digits needed. This returns zero for 0. */
+ tmpval = val;
+ while ( tmpval ) {
+ tmpval /= base;
+ ndigits++;
+ }
+
+ /* Adjust ndigits for size of output */
+
+ if ( flags & FL_HASH && base == 8 ) {
+ if ( prec < ndigits+1 )
+ prec = ndigits+1;
+ }
+
+ if ( ndigits < prec ) {
+ ndigits = prec; /* Mandatory number padding */
+ } else if ( val == 0 ) {
+ ndigits = 1; /* Zero still requires space */
+ }
+
+ /* For ', figure out what the skip should be */
+ if ( flags & FL_TICK ) {
+ tickskip = (base == 16) ? 4 : 3;
+ } else {
+ tickskip = ndigits; /* No tick marks */
+ }
+
+ /* Tick marks aren't digits, but generated by the number converter */
+ ndigits += (ndigits-1)/tickskip;
+
+ /* Now compute the number of nondigits */
+ nchars = ndigits;
+
+ if ( minus || (flags & (FL_PLUS|FL_SPACE)) )
+ nchars++; /* Need space for sign */
+ if ( (flags & FL_HASH) && base == 16 ) {
+ nchars += 2; /* Add 0x for hex */
+ }
+
+ /* Emit early space padding */
+ if ( !(flags & (FL_MINUS|FL_ZERO)) && width > nchars ) {
+ while ( width > nchars ) {
+ EMIT(' ');
+ width--;
+ }
+ }
+
+ /* Emit nondigits */
+ if ( minus )
+ EMIT('-');
+ else if ( flags & FL_PLUS )
+ EMIT('+');
+ else if ( flags & FL_SPACE )
+ EMIT(' ');
+
+ if ( (flags & FL_HASH) && base == 16 ) {
+ EMIT('0');
+ EMIT((flags & FL_UPPER) ? 'X' : 'x');
+ }
+
+ /* Emit zero padding */
+ if ( (flags & (FL_MINUS|FL_ZERO)) == FL_ZERO && width > ndigits ) {
+ while ( width > nchars ) {
+ EMIT('0');
+ width--;
+ }
+ }
+
+ /* Generate the number. This is done from right to left. */
+ ASSERT(ndigits <= NDIGITS_MAX); /* DHH */
+ ndigits_save = ndigits;
+ qq = digit_buffer + ndigits;
+ oo = o;
+
+ /* Emit digits to temp buffer */
+ b4tick = tickskip;
+ while ( ndigits > 0 ) {
+ if ( !b4tick-- ) {
+ qq--; oo--; ndigits--;
+ *qq = '_';
+ b4tick = tickskip-1;
+ }
+ qq--; oo--; ndigits--;
+ *qq = digits[val%base];
+ val /= base;
+ }
+
+ /* Copy digits to Output_Sink */
+ for (oo = 0; oo < ndigits_save; ++oo)
+ EMIT(digit_buffer[oo]);
+
+ /* Emit late space padding */
+ while ( (flags & FL_MINUS) && width > nchars ) {
+ EMIT(' ');
+ width--;
+ }
+
+ return o;
+}
+
+/*
+ * DHH - This function was originally vsnprintf().
+ * I renamed it to Format_Output() and changed it to take
+ * a struct Output_Sink instead of a buffer. That way, it can
+ * be used for any kind of formatted output (string, console,
+ * file, etc.)
+ */
+int Format_Output(struct Output_Sink *q, const char *format, va_list ap)
+{
+ const char *p = format;
+ char ch;
+ size_t o = 0; /* Number of characters output */
+ uintmax_t val = 0;
+ int rank = rank_int; /* Default rank */
+ int width = 0;
+ int prec = -1;
+ int base;
+ size_t sz;
+ enum flags flags = 0;
+ enum {
+ st_normal, /* Ground state */
+ st_flags, /* Special flags */
+ st_width, /* Field width */
+ st_prec, /* Field precision */
+ st_modifiers /* Length or conversion modifiers */
+ } state = st_normal;
+ const char *sarg; /* %s string argument */
+ char carg; /* %c char argument */
+ int slen; /* String length */
+
+ while ( (ch = *p++) ) {
+ switch ( state ) {
+ case st_normal:
+ if ( ch == '%' ) {
+ state = st_flags;
+ flags = 0; rank = rank_int; width = 0; prec = -1;
+ } else {
+ EMIT(ch);
+ }
+ break;
+
+ case st_flags:
+ switch ( ch ) {
+ case '-':
+ flags |= FL_MINUS;
+ break;
+ case '+':
+ flags |= FL_PLUS;
+ break;
+ case '\'':
+ flags |= FL_TICK;
+ break;
+ case ' ':
+ flags |= FL_SPACE;
+ break;
+ case '#':
+ flags |= FL_HASH;
+ break;
+ case '0':
+ flags |= FL_ZERO;
+ break;
+ default:
+ state = st_width;
+ p--; /* Process this character again */
+ break;
+ }
+ break;
+
+ case st_width:
+ if ( ch >= '0' && ch <= '9' ) {
+ width = width*10+(ch-'0');
+ } else if ( ch == '*' ) {
+ width = va_arg(ap, int);
+ if ( width < 0 ) {
+ width = -width;
+ flags |= FL_MINUS;
+ }
+ } else if ( ch == '.' ) {
+ prec = 0; /* Precision given */
+ state = st_prec;
+ } else {
+ state = st_modifiers;
+ p--; /* Process this character again */
+ }
+ break;
+
+ case st_prec:
+ if ( ch >= '0' && ch <= '9' ) {
+ prec = prec*10+(ch-'0');
+ } else if ( ch == '*' ) {
+ prec = va_arg(ap, int);
+ if ( prec < 0 )
+ prec = -1;
+ } else {
+ state = st_modifiers;
+ p--; /* Process this character again */
+ }
+ break;
+
+ case st_modifiers:
+ switch ( ch ) {
+ /* Length modifiers - nonterminal sequences */
+ case 'h':
+ rank--; /* Shorter rank */
+ break;
+ case 'l':
+ rank++; /* Longer rank */
+ break;
+ case 'j':
+ rank = INTMAX_RANK;
+ break;
+ case 'z':
+ rank = SIZE_T_RANK;
+ break;
+ case 't':
+ rank = PTRDIFF_T_RANK;
+ break;
+ case 'L':
+ case 'q':
+ rank += 2;
+ break;
+ default:
+ /* Output modifiers - terminal sequences */
+ state = st_normal; /* Next state will be normal */
+ if ( rank < MIN_RANK ) /* Canonicalize rank */
+ rank = MIN_RANK;
+ else if ( rank > MAX_RANK )
+ rank = MAX_RANK;
+
+ switch ( ch ) {
+ case 'P': /* Upper case pointer */
+ flags |= FL_UPPER;
+ /* fall through */
+ case 'p': /* Pointer */
+ base = 16;
+ prec = (CHAR_BIT*sizeof(void *)+3)/4;
+ flags |= FL_HASH;
+ val = (uintmax_t)(uintptr_t)va_arg(ap, void *);
+ goto is_integer;
+
+ case 'd': /* Signed decimal output */
+ case 'i':
+ base = 10;
+ flags |= FL_SIGNED;
+ switch (rank) {
+ case rank_char:
+ /* Yes, all these casts are needed... */
+ val = (uintmax_t)(intmax_t)(signed char)va_arg(ap, signed int);
+ break;
+ case rank_short:
+ val = (uintmax_t)(intmax_t)(signed short)va_arg(ap, signed int);
+ break;
+ case rank_int:
+ val = (uintmax_t)(intmax_t)va_arg(ap, signed int);
+ break;
+ case rank_long:
+ val = (uintmax_t)(intmax_t)va_arg(ap, signed long);
+ break;
+#if 0
+ case rank_longlong:
+ val = (uintmax_t)(intmax_t)va_arg(ap, signed long long);
+ break;
+#endif
+ }
+ goto is_integer;
+ case 'o': /* Octal */
+ base = 8;
+ goto is_unsigned;
+ case 'u': /* Unsigned decimal */
+ base = 10;
+ goto is_unsigned;
+ case 'X': /* Upper case hexadecimal */
+ flags |= FL_UPPER;
+ /* fall through */
+ case 'x': /* Hexadecimal */
+ base = 16;
+ goto is_unsigned;
+
+ is_unsigned:
+ switch (rank) {
+ case rank_char:
+ val = (uintmax_t)(unsigned char)va_arg(ap, unsigned int);
+ break;
+ case rank_short:
+ val = (uintmax_t)(unsigned short)va_arg(ap, unsigned int);
+ break;
+ case rank_int:
+ val = (uintmax_t)va_arg(ap, unsigned int);
+ break;
+ case rank_long:
+ val = (uintmax_t)va_arg(ap, unsigned long);
+ break;
+#if 0
+ case rank_longlong:
+ val = (uintmax_t)va_arg(ap, unsigned long long);
+ break;
+#endif
+ }
+ /* fall through */
+
+ is_integer:
+ sz = format_int(q, val, flags, base, width, prec);
+ q += sz; o += sz;
+ break;
+
+ case 'c': /* Character */
+ carg = (char)va_arg(ap, int);
+ sarg = &carg;
+ slen = 1;
+ goto is_string;
+ case 's': /* String */
+ sarg = va_arg(ap, const char *);
+ sarg = sarg ? sarg : "(null)";
+ slen = strlen(sarg);
+ goto is_string;
+
+ is_string:
+ {
+ char sch;
+ int i;
+
+ if ( prec != -1 && slen > prec )
+ slen = prec;
+
+ if ( width > slen && !(flags & FL_MINUS) ) {
+ char pad = (flags & FL_ZERO) ? '0' : ' ';
+ while ( width > slen ) {
+ EMIT(pad);
+ width--;
+ }
+ }
+ for ( i = slen ; i ; i-- ) {
+ sch = *sarg++;
+ EMIT(sch);
+ }
+ if ( width > slen && (flags & FL_MINUS) ) {
+ while ( width > slen ) {
+ EMIT(' ');
+ width--;
+ }
+ }
+ }
+ break;
+
+ case 'n': /* Output the number of characters written */
+ {
+ switch (rank) {
+ case rank_char:
+ *va_arg(ap, signed char *) = o;
+ break;
+ case rank_short:
+ *va_arg(ap, signed short *) = o;
+ break;
+ case rank_int:
+ *va_arg(ap, signed int *) = o;
+ break;
+ case rank_long:
+ *va_arg(ap, signed long *) = o;
+ break;
+#if 0
+ case rank_longlong:
+ *va_arg(ap, signed long long *) = o;
+ break;
+#endif
+ }
+ }
+ break;
+
+ default: /* Anything else, including % */
+ EMIT(ch);
+ break;
+ }
+ }
+ }
+ }
+
+ /* Null-terminate the string */
+#if 0
+ if ( o<n )
+ *q = '\0'; /* No overflow */
+ else if ( n>0 )
+ buffer[n-1] = '\0'; /* Overflow - terminate at end of buffer */
+#endif
+ q->Finish(q);
+
+ return o;
+}
