Add a "fork" of musl as //fusl.

fusl/src/stdio/vfprintf.c

+#include "stdio_impl.h"
+#include <errno.h>
+#include <ctype.h>
+#include <limits.h>
+#include <string.h>
+#include <stdarg.h>
+#include <wchar.h>
+#include <inttypes.h>
+#include <math.h>
+#include <float.h>
+
+/* Some useful macros */
+
+#define MAX(a,b) ((a)>(b) ? (a) : (b))
+#define MIN(a,b) ((a)<(b) ? (a) : (b))
+
+/* Convenient bit representation for modifier flags, which all fall
+ * within 31 codepoints of the space character. */
+
+#define ALT_FORM   (1U<<'#'-' ')
+#define ZERO_PAD   (1U<<'0'-' ')
+#define LEFT_ADJ   (1U<<'-'-' ')
+#define PAD_POS    (1U<<' '-' ')
+#define MARK_POS   (1U<<'+'-' ')
+#define GROUPED    (1U<<'\''-' ')
+
+#define FLAGMASK (ALT_FORM|ZERO_PAD|LEFT_ADJ|PAD_POS|MARK_POS|GROUPED)
+
+#if UINT_MAX == ULONG_MAX
+#define LONG_IS_INT
+#endif
+
+#if SIZE_MAX != ULONG_MAX || UINTMAX_MAX != ULLONG_MAX
+#define ODD_TYPES
+#endif
+
+/* State machine to accept length modifiers + conversion specifiers.
+ * Result is 0 on failure, or an argument type to pop on success. */
+
+enum {
+        BARE, LPRE, LLPRE, HPRE, HHPRE, BIGLPRE,
+        ZTPRE, JPRE,
+        STOP,
+        PTR, INT, UINT, ULLONG,
+#ifndef LONG_IS_INT
+        LONG, ULONG,
+#else
+#define LONG INT
+#define ULONG UINT
+#endif
+        SHORT, USHORT, CHAR, UCHAR,
+#ifdef ODD_TYPES
+        LLONG, SIZET, IMAX, UMAX, PDIFF, UIPTR,
+#else
+#define LLONG ULLONG
+#define SIZET ULONG
+#define IMAX LLONG
+#define UMAX ULLONG
+#define PDIFF LONG
+#define UIPTR ULONG
+#endif
+        DBL, LDBL,
+        NOARG,
+        MAXSTATE
+};
+
+#define S(x) [(x)-'A']
+
+static const unsigned char states[]['z'-'A'+1] = {
+        { /* 0: bare types */
+                S('d') = INT, S('i') = INT,
+                S('o') = UINT, S('u') = UINT, S('x') = UINT, S('X') = UINT,
+                S('e') = DBL, S('f') = DBL, S('g') = DBL, S('a') = DBL,
+                S('E') = DBL, S('F') = DBL, S('G') = DBL, S('A') = DBL,
+                S('c') = CHAR, S('C') = INT,
+                S('s') = PTR, S('S') = PTR, S('p') = UIPTR, S('n') = PTR,
+                S('m') = NOARG,
+                S('l') = LPRE, S('h') = HPRE, S('L') = BIGLPRE,
+                S('z') = ZTPRE, S('j') = JPRE, S('t') = ZTPRE,
+        }, { /* 1: l-prefixed */
+                S('d') = LONG, S('i') = LONG,
+                S('o') = ULONG, S('u') = ULONG, S('x') = ULONG, S('X') = ULONG,
+                S('e') = DBL, S('f') = DBL, S('g') = DBL, S('a') = DBL,
+                S('E') = DBL, S('F') = DBL, S('G') = DBL, S('A') = DBL,
+                S('c') = INT, S('s') = PTR, S('n') = PTR,
+                S('l') = LLPRE,
+        }, { /* 2: ll-prefixed */
+                S('d') = LLONG, S('i') = LLONG,
+                S('o') = ULLONG, S('u') = ULLONG,
+                S('x') = ULLONG, S('X') = ULLONG,
+                S('n') = PTR,
+        }, { /* 3: h-prefixed */
+                S('d') = SHORT, S('i') = SHORT,
+                S('o') = USHORT, S('u') = USHORT,
+                S('x') = USHORT, S('X') = USHORT,
+                S('n') = PTR,
+                S('h') = HHPRE,
+        }, { /* 4: hh-prefixed */
+                S('d') = CHAR, S('i') = CHAR,
+                S('o') = UCHAR, S('u') = UCHAR,
+                S('x') = UCHAR, S('X') = UCHAR,
+                S('n') = PTR,
+        }, { /* 5: L-prefixed */
+                S('e') = LDBL, S('f') = LDBL, S('g') = LDBL, S('a') = LDBL,
+                S('E') = LDBL, S('F') = LDBL, S('G') = LDBL, S('A') = LDBL,
+                S('n') = PTR,
+        }, { /* 6: z- or t-prefixed (assumed to be same size) */
+                S('d') = PDIFF, S('i') = PDIFF,
+                S('o') = SIZET, S('u') = SIZET,
+                S('x') = SIZET, S('X') = SIZET,
+                S('n') = PTR,
+        }, { /* 7: j-prefixed */
+                S('d') = IMAX, S('i') = IMAX,
+                S('o') = UMAX, S('u') = UMAX,
+                S('x') = UMAX, S('X') = UMAX,
+                S('n') = PTR,
+        }
+};
+
+#define OOB(x) ((unsigned)(x)-'A' > 'z'-'A')
+
+union arg
+{
+        uintmax_t i;
+        long double f;
+        void *p;
+};
+
+static void pop_arg(union arg *arg, int type, va_list *ap)
+{
+        /* Give the compiler a hint for optimizing the switch. */
+        if ((unsigned)type > MAXSTATE) return;
+        switch (type) {
+               case PTR:        arg->p = va_arg(*ap, void *);
+        break; case INT:        arg->i = va_arg(*ap, int);
+        break; case UINT:       arg->i = va_arg(*ap, unsigned int);
+#ifndef LONG_IS_INT
+        break; case LONG:       arg->i = va_arg(*ap, long);
+        break; case ULONG:      arg->i = va_arg(*ap, unsigned long);
+#endif
+        break; case ULLONG:     arg->i = va_arg(*ap, unsigned long long);
+        break; case SHORT:      arg->i = (short)va_arg(*ap, int);
+        break; case USHORT:     arg->i = (unsigned short)va_arg(*ap, int);
+        break; case CHAR:       arg->i = (signed char)va_arg(*ap, int);
+        break; case UCHAR:      arg->i = (unsigned char)va_arg(*ap, int);
+#ifdef ODD_TYPES
+        break; case LLONG:      arg->i = va_arg(*ap, long long);
+        break; case SIZET:      arg->i = va_arg(*ap, size_t);
+        break; case IMAX:       arg->i = va_arg(*ap, intmax_t);
+        break; case UMAX:       arg->i = va_arg(*ap, uintmax_t);
+        break; case PDIFF:      arg->i = va_arg(*ap, ptrdiff_t);
+        break; case UIPTR:      arg->i = (uintptr_t)va_arg(*ap, void *);
+#endif
+        break; case DBL:        arg->f = va_arg(*ap, double);
+        break; case LDBL:       arg->f = va_arg(*ap, long double);
+        }
+}
+
+static void out(FILE *f, const char *s, size_t l)
+{
+        if (!(f->flags & F_ERR)) __fwritex((void *)s, l, f);
+}
+
+static void pad(FILE *f, char c, int w, int l, int fl)
+{
+        char pad[256];
+        if (fl & (LEFT_ADJ | ZERO_PAD) || l >= w) return;
+        l = w - l;
+        memset(pad, c, l>sizeof pad ? sizeof pad : l);
+        for (; l >= sizeof pad; l -= sizeof pad)
+                out(f, pad, sizeof pad);
+        out(f, pad, l);
+}
+
+static const char xdigits[16] = {
+        "0123456789ABCDEF"
+};
+
+static char *fmt_x(uintmax_t x, char *s, int lower)
+{
+        for (; x; x>>=4) *--s = xdigits[(x&15)]|lower;
+        return s;
+}
+
+static char *fmt_o(uintmax_t x, char *s)
+{
+        for (; x; x>>=3) *--s = '0' + (x&7);
+        return s;
+}
+
+static char *fmt_u(uintmax_t x, char *s)
+{
+        unsigned long y;
+        for (   ; x>ULONG_MAX; x/=10) *--s = '0' + x%10;
+        for (y=x;           y; y/=10) *--s = '0' + y%10;
+        return s;
+}
+
+/* Do not override this check. The floating point printing code below
+ * depends on the float.h constants being right. If they are wrong, it
+ * may overflow the stack. */
+#if LDBL_MANT_DIG == 53
+typedef char compiler_defines_long_double_incorrectly[9-(int)sizeof(long double)];
+#endif
+
+static int fmt_fp(FILE *f, long double y, int w, int p, int fl, int t)
+{
+        uint32_t big[(LDBL_MANT_DIG+28)/29 + 1          // mantissa expansion
+                + (LDBL_MAX_EXP+LDBL_MANT_DIG+28+8)/9]; // exponent expansion
+        uint32_t *a, *d, *r, *z;
+        int e2=0, e, i, j, l;
+        char buf[9+LDBL_MANT_DIG/4], *s;
+        const char *prefix="-0X+0X 0X-0x+0x 0x";
+        int pl;
+        char ebuf0[3*sizeof(int)], *ebuf=&ebuf0[3*sizeof(int)], *estr;
+
+        pl=1;
+        if (signbit(y)) {
+                y=-y;
+        } else if (fl & MARK_POS) {
+                prefix+=3;
+        } else if (fl & PAD_POS) {
+                prefix+=6;
+        } else prefix++, pl=0;
+
+        if (!isfinite(y)) {
+                char *s = (t&32)?"inf":"INF";
+                if (y!=y) s=(t&32)?"nan":"NAN";
+                pad(f, ' ', w, 3+pl, fl&~ZERO_PAD);
+                out(f, prefix, pl);
+                out(f, s, 3);
+                pad(f, ' ', w, 3+pl, fl^LEFT_ADJ);
+                return MAX(w, 3+pl);
+        }
+
+        y = frexpl(y, &e2) * 2;
+        if (y) e2--;
+
+        if ((t|32)=='a') {
+                long double round = 8.0;
+                int re;
+
+                if (t&32) prefix += 9;
+                pl += 2;
+
+                if (p<0 || p>=LDBL_MANT_DIG/4-1) re=0;
+                else re=LDBL_MANT_DIG/4-1-p;
+
+                if (re) {
+                        while (re--) round*=16;
+                        if (*prefix=='-') {
+                                y=-y;
+                                y-=round;
+                                y+=round;
+                                y=-y;
+                        } else {
+                                y+=round;
+                                y-=round;
+                        }
+                }
+
+                estr=fmt_u(e2<0 ? -e2 : e2, ebuf);
+                if (estr==ebuf) *--estr='0';
+                *--estr = (e2<0 ? '-' : '+');
+                *--estr = t+('p'-'a');
+
+                s=buf;
+                do {
+                        int x=y;
+                        *s++=xdigits[x]|(t&32);
+                        y=16*(y-x);
+                        if (s-buf==1 && (y||p>0||(fl&ALT_FORM))) *s++='.';
+                } while (y);
+
+                if (p && s-buf-2 < p)
+                        l = (p+2) + (ebuf-estr);
+                else
+                        l = (s-buf) + (ebuf-estr);
+
+                pad(f, ' ', w, pl+l, fl);
+                out(f, prefix, pl);
+                pad(f, '0', w, pl+l, fl^ZERO_PAD);
+                out(f, buf, s-buf);
+                pad(f, '0', l-(ebuf-estr)-(s-buf), 0, 0);
+                out(f, estr, ebuf-estr);
+                pad(f, ' ', w, pl+l, fl^LEFT_ADJ);
+                return MAX(w, pl+l);
+        }
+        if (p<0) p=6;
+
+        if (y) y *= 0x1p28, e2-=28;
+
+        if (e2<0) a=r=z=big;
+        else a=r=z=big+sizeof(big)/sizeof(*big) - LDBL_MANT_DIG - 1;
+
+        do {
+                *z = y;
+                y = 1000000000*(y-*z++);
+        } while (y);
+
+        while (e2>0) {
+                uint32_t carry=0;
+                int sh=MIN(29,e2);
+                for (d=z-1; d>=a; d--) {
+                        uint64_t x = ((uint64_t)*d<<sh)+carry;
+                        *d = x % 1000000000;
+                        carry = x / 1000000000;
+                }
+                if (carry) *--a = carry;
+                while (z>a && !z[-1]) z--;
+                e2-=sh;
+        }
+        while (e2<0) {
+                uint32_t carry=0, *b;
+                int sh=MIN(9,-e2), need=1+(p+LDBL_MANT_DIG/3+8)/9;
+                for (d=a; d<z; d++) {
+                        uint32_t rm = *d & (1<<sh)-1;
+                        *d = (*d>>sh) + carry;
+                        carry = (1000000000>>sh) * rm;
+                }
+                if (!*a) a++;
+                if (carry) *z++ = carry;
+                /* Avoid (slow!) computation past requested precision */
+                b = (t|32)=='f' ? r : a;
+                if (z-b > need) z = b+need;
+                e2+=sh;
+        }
+
+        if (a<z) for (i=10, e=9*(r-a); *a>=i; i*=10, e++);
+        else e=0;
+
+        /* Perform rounding: j is precision after the radix (possibly neg) */
+        j = p - ((t|32)!='f')*e - ((t|32)=='g' && p);
+        if (j < 9*(z-r-1)) {
+                uint32_t x;
+                /* We avoid C's broken division of negative numbers */
+                d = r + 1 + ((j+9*LDBL_MAX_EXP)/9 - LDBL_MAX_EXP);
+                j += 9*LDBL_MAX_EXP;
+                j %= 9;
+                for (i=10, j++; j<9; i*=10, j++);
+                x = *d % i;
+                /* Are there any significant digits past j? */
+                if (x || d+1!=z) {
+                        long double round = 2/LDBL_EPSILON;
+                        long double small;
+                        if (*d/i & 1) round += 2;
+                        if (x<i/2) small=0x0.8p0;
+                        else if (x==i/2 && d+1==z) small=0x1.0p0;
+                        else small=0x1.8p0;
+                        if (pl && *prefix=='-') round*=-1, small*=-1;
+                        *d -= x;
+                        /* Decide whether to round by probing round+small */
+                        if (round+small != round) {
+                                *d = *d + i;
+                                while (*d > 999999999) {
+                                        *d--=0;
+                                        if (d<a) *--a=0;
+                                        (*d)++;
+                                }
+                                for (i=10, e=9*(r-a); *a>=i; i*=10, e++);
+                        }
+                }
+                if (z>d+1) z=d+1;
+        }
+        for (; z>a && !z[-1]; z--);
+        
+        if ((t|32)=='g') {
+                if (!p) p++;
+                if (p>e && e>=-4) {
+                        t--;
+                        p-=e+1;
+                } else {
+                        t-=2;
+                        p--;
+                }
+                if (!(fl&ALT_FORM)) {
+                        /* Count trailing zeros in last place */
+                        if (z>a && z[-1]) for (i=10, j=0; z[-1]%i==0; i*=10, j++);
+                        else j=9;
+                        if ((t|32)=='f')
+                                p = MIN(p,MAX(0,9*(z-r-1)-j));
+                        else
+                                p = MIN(p,MAX(0,9*(z-r-1)+e-j));
+                }
+        }
+        l = 1 + p + (p || (fl&ALT_FORM));
+        if ((t|32)=='f') {
+                if (e>0) l+=e;
+        } else {
+                estr=fmt_u(e<0 ? -e : e, ebuf);
+                while(ebuf-estr<2) *--estr='0';
+                *--estr = (e<0 ? '-' : '+');
+                *--estr = t;
+                l += ebuf-estr;
+        }
+
+        pad(f, ' ', w, pl+l, fl);
+        out(f, prefix, pl);
+        pad(f, '0', w, pl+l, fl^ZERO_PAD);
+
+        if ((t|32)=='f') {
+                if (a>r) a=r;
+                for (d=a; d<=r; d++) {
+                        char *s = fmt_u(*d, buf+9);
+                        if (d!=a) while (s>buf) *--s='0';
+                        else if (s==buf+9) *--s='0';
+                        out(f, s, buf+9-s);
+                }
+                if (p || (fl&ALT_FORM)) out(f, ".", 1);
+                for (; d<z && p>0; d++, p-=9) {
+                        char *s = fmt_u(*d, buf+9);
+                        while (s>buf) *--s='0';
+                        out(f, s, MIN(9,p));
+                }
+                pad(f, '0', p+9, 9, 0);
+        } else {
+                if (z<=a) z=a+1;
+                for (d=a; d<z && p>=0; d++) {
+                        char *s = fmt_u(*d, buf+9);
+                        if (s==buf+9) *--s='0';
+                        if (d!=a) while (s>buf) *--s='0';
+                        else {
+                                out(f, s++, 1);
+                                if (p>0||(fl&ALT_FORM)) out(f, ".", 1);
+                        }
+                        out(f, s, MIN(buf+9-s, p));
+                        p -= buf+9-s;
+                }
+                pad(f, '0', p+18, 18, 0);
+                out(f, estr, ebuf-estr);
+        }
+
+        pad(f, ' ', w, pl+l, fl^LEFT_ADJ);
+
+        return MAX(w, pl+l);
+}
+
+static int getint(char **s) {
+        int i;
+        for (i=0; isdigit(**s); (*s)++)
+                i = 10*i + (**s-'0');
+        return i;
+}
+
+static int printf_core(FILE *f, const char *fmt, va_list *ap, union arg *nl_arg, int *nl_type)
+{
+        char *a, *z, *s=(char *)fmt;
+        unsigned l10n=0, fl;
+        int w, p;
+        union arg arg;
+        int argpos;
+        unsigned st, ps;
+        int cnt=0, l=0;
+        int i;
+        char buf[sizeof(uintmax_t)*3+3+LDBL_MANT_DIG/4];
+        const char *prefix;
+        int t, pl;
+        wchar_t wc[2], *ws;
+        char mb[4];
+
+        for (;;) {
+                /* Update output count, end loop when fmt is exhausted */
+                if (cnt >= 0) {
+                        if (l > INT_MAX - cnt) {
+                                errno = EOVERFLOW;
+                                cnt = -1;
+                        } else cnt += l;
+                }
+                if (!*s) break;
+
+                /* Handle literal text and %% format specifiers */
+                for (a=s; *s && *s!='%'; s++);
+                for (z=s; s[0]=='%' && s[1]=='%'; z++, s+=2);
+                l = z-a;
+                if (f) out(f, a, l);
+                if (l) continue;
+
+                if (isdigit(s[1]) && s[2]=='$') {
+                        l10n=1;
+                        argpos = s[1]-'0';
+                        s+=3;
+                } else {
+                        argpos = -1;
+                        s++;
+                }
+
+                /* Read modifier flags */
+                for (fl=0; (unsigned)*s-' '<32 && (FLAGMASK&(1U<<*s-' ')); s++)
+                        fl |= 1U<<*s-' ';
+
+                /* Read field width */
+                if (*s=='*') {
+                        if (isdigit(s[1]) && s[2]=='$') {
+                                l10n=1;
+                                nl_type[s[1]-'0'] = INT;
+                                w = nl_arg[s[1]-'0'].i;
+                                s+=3;
+                        } else if (!l10n) {
+                                w = f ? va_arg(*ap, int) : 0;
+                                s++;
+                        } else return -1;
+                        if (w<0) fl|=LEFT_ADJ, w=-w;
+                } else if ((w=getint(&s))<0) return -1;
+
+                /* Read precision */
+                if (*s=='.' && s[1]=='*') {
+                        if (isdigit(s[2]) && s[3]=='$') {
+                                nl_type[s[2]-'0'] = INT;
+                                p = nl_arg[s[2]-'0'].i;
+                                s+=4;
+                        } else if (!l10n) {
+                                p = f ? va_arg(*ap, int) : 0;
+                                s+=2;
+                        } else return -1;
+                } else if (*s=='.') {
+                        s++;
+                        p = getint(&s);
+                } else p = -1;
+
+                /* Format specifier state machine */
+                st=0;
+                do {
+                        if (OOB(*s)) return -1;
+                        ps=st;
+                        st=states[st]S(*s++);
+                } while (st-1<STOP);
+                if (!st) return -1;
+
+                /* Check validity of argument type (nl/normal) */
+                if (st==NOARG) {
+                        if (argpos>=0) return -1;
+                } else {
+                        if (argpos>=0) nl_type[argpos]=st, arg=nl_arg[argpos];
+                        else if (f) pop_arg(&arg, st, ap);
+                        else return 0;
+                }
+
+                if (!f) continue;
+
+                z = buf + sizeof(buf);
+                prefix = "-+   0X0x";
+                pl = 0;
+                t = s[-1];
+
+                /* Transform ls,lc -> S,C */
+                if (ps && (t&15)==3) t&=~32;
+
+                /* - and 0 flags are mutually exclusive */
+                if (fl & LEFT_ADJ) fl &= ~ZERO_PAD;
+
+                switch(t) {
+                case 'n':
+                        switch(ps) {
+                        case BARE: *(int *)arg.p = cnt; break;
+                        case LPRE: *(long *)arg.p = cnt; break;
+                        case LLPRE: *(long long *)arg.p = cnt; break;
+                        case HPRE: *(unsigned short *)arg.p = cnt; break;
+                        case HHPRE: *(unsigned char *)arg.p = cnt; break;
+                        case ZTPRE: *(size_t *)arg.p = cnt; break;
+                        case JPRE: *(uintmax_t *)arg.p = cnt; break;
+                        }
+                        continue;
+                case 'p':
+                        p = MAX(p, 2*sizeof(void*));
+                        t = 'x';
+                        fl |= ALT_FORM;
+                case 'x': case 'X':
+                        a = fmt_x(arg.i, z, t&32);
+                        if (arg.i && (fl & ALT_FORM)) prefix+=(t>>4), pl=2;
+                        if (0) {
+                case 'o':
+                        a = fmt_o(arg.i, z);
+                        if ((fl&ALT_FORM) && p<z-a+1) p=z-a+1;
+                        } if (0) {
+                case 'd': case 'i':
+                        pl=1;
+                        if (arg.i>INTMAX_MAX) {
+                                arg.i=-arg.i;
+                        } else if (fl & MARK_POS) {
+                                prefix++;
+                        } else if (fl & PAD_POS) {
+                                prefix+=2;
+                        } else pl=0;
+                case 'u':
+                        a = fmt_u(arg.i, z);
+                        }
+                        if (p>=0) fl &= ~ZERO_PAD;
+                        if (!arg.i && !p) {
+                                a=z;
+                                break;
+                        }
+                        p = MAX(p, z-a + !arg.i);
+                        break;
+                case 'c':
+                        *(a=z-(p=1))=arg.i;
+                        fl &= ~ZERO_PAD;
+                        break;
+                case 'm':
+                        if (1) a = strerror(errno); else
+                case 's':
+                        a = arg.p ? arg.p : "(null)";
+                        z = memchr(a, 0, p);
+                        if (!z) z=a+p;
+                        else p=z-a;
+                        fl &= ~ZERO_PAD;
+                        break;
+                case 'C':
+                        wc[0] = arg.i;
+                        wc[1] = 0;
+                        arg.p = wc;
+                        p = -1;
+                case 'S':
+                        ws = arg.p;
+                        for (i=l=0; i<0U+p && *ws && (l=wctomb(mb, *ws++))>=0 && l<=0U+p-i; i+=l);
+                        if (l<0) return -1;
+                        p = i;
+                        pad(f, ' ', w, p, fl);
+                        ws = arg.p;
+                        for (i=0; i<0U+p && *ws && i+(l=wctomb(mb, *ws++))<=p; i+=l)
+                                out(f, mb, l);
+                        pad(f, ' ', w, p, fl^LEFT_ADJ);
+                        l = w>p ? w : p;
+                        continue;
+                case 'e': case 'f': case 'g': case 'a':
+                case 'E': case 'F': case 'G': case 'A':
+                        l = fmt_fp(f, arg.f, w, p, fl, t);
+                        continue;
+                }
+
+                if (p < z-a) p = z-a;
+                if (w < pl+p) w = pl+p;
+
+                pad(f, ' ', w, pl+p, fl);
+                out(f, prefix, pl);
+                pad(f, '0', w, pl+p, fl^ZERO_PAD);
+                pad(f, '0', p, z-a, 0);
+                out(f, a, z-a);
+                pad(f, ' ', w, pl+p, fl^LEFT_ADJ);
+
+                l = w;
+        }
+
+        if (f) return cnt;
+        if (!l10n) return 0;
+
+        for (i=1; i<=NL_ARGMAX && nl_type[i]; i++)
+                pop_arg(nl_arg+i, nl_type[i], ap);
+        for (; i<=NL_ARGMAX && !nl_type[i]; i++);
+        if (i<=NL_ARGMAX) return -1;
+        return 1;
+}
+
+int vfprintf(FILE *restrict f, const char *restrict fmt, va_list ap)
+{
+        va_list ap2;
+        int nl_type[NL_ARGMAX+1] = {0};
+        union arg nl_arg[NL_ARGMAX+1];
+        unsigned char internal_buf[80], *saved_buf = 0;
+        int olderr;
+        int ret;
+
+        /* the copy allows passing va_list* even if va_list is an array */
+        va_copy(ap2, ap);
+        if (printf_core(0, fmt, &ap2, nl_arg, nl_type) < 0) {
+                va_end(ap2);
+                return -1;
+        }
+
+        FLOCK(f);
+        olderr = f->flags & F_ERR;
+        if (f->mode < 1) f->flags &= ~F_ERR;
+        if (!f->buf_size) {
+                saved_buf = f->buf;
+                f->wpos = f->wbase = f->buf = internal_buf;
+                f->buf_size = sizeof internal_buf;
+                f->wend = internal_buf + sizeof internal_buf;
+        }
+        ret = printf_core(f, fmt, &ap2, nl_arg, nl_type);
+        if (saved_buf) {
+                f->write(f, 0, 0);
+                if (!f->wpos) ret = -1;
+                f->buf = saved_buf;
+                f->buf_size = 0;
+                f->wpos = f->wbase = f->wend = 0;
+        }
+        if (f->flags & F_ERR) ret = -1;
+        f->flags |= olderr;
+        FUNLOCK(f);
+        va_end(ap2);
+        return ret;
+}