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

fusl/src/stdio/vfwprintf.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>
+
+/* 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('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 wchar_t *s, size_t l)
+{
+        while (l-- && !(f->flags & F_ERR)) fputwc(*s++, f);
+}
+
+static int getint(wchar_t **s) {
+        int i;
+        for (i=0; iswdigit(**s); (*s)++)
+                i = 10*i + (**s-'0');
+        return i;
+}
+
+static const char sizeprefix['y'-'a'] = {
+['a'-'a']='L', ['e'-'a']='L', ['f'-'a']='L', ['g'-'a']='L',
+['d'-'a']='j', ['i'-'a']='j', ['o'-'a']='j', ['u'-'a']='j', ['x'-'a']='j',
+['p'-'a']='j'
+};
+
+static int wprintf_core(FILE *f, const wchar_t *fmt, va_list *ap, union arg *nl_arg, int *nl_type)
+{
+        wchar_t *a, *z, *s=(wchar_t *)fmt;
+        unsigned l10n=0, litpct, fl;
+        int w, p;
+        union arg arg;
+        int argpos;
+        unsigned st, ps;
+        int cnt=0, l=0;
+        int i;
+        int t;
+        char *bs;
+        char charfmt[16];
+        wchar_t wc;
+
+        for (;;) {
+                /* Update output count, end loop when fmt is exhausted */
+                if (cnt >= 0) {
+                        if (l > INT_MAX - cnt) {
+                                if (!ferror(f)) errno = EOVERFLOW;
+                                cnt = -1;
+                        } else cnt += l;
+                }
+                if (!*s) break;
+
+                /* Handle literal text and %% format specifiers */
+                for (a=s; *s && *s!='%'; s++);
+                litpct = wcsspn(s, L"%")/2; /* Optimize %%%% runs */
+                z = s+litpct;
+                s += 2*litpct;
+                l = z-a;
+                if (f) out(f, a, l);
+                if (l) continue;
+
+                if (iswdigit(s[1]) && s[2]=='$') {
+                        l10n=1;
+                        argpos = s[1]-'0';
+                        s+=3;
+                } else {
+                        argpos = -1;
+                        s++;
+                }
+
+                /* Read modifier flags */
+                for (fl=0; (unsigned)*s-' '<32 && (FLAGMASK&(1U<<*s-' ')); s++)
+                        fl |= 1U<<*s-' ';
+
+                /* Read field width */
+                if (*s=='*') {
+                        if (iswdigit(s[1]) && s[2]=='$') {
+                                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;
+                t = s[-1];
+                if (ps && (t&15)==3) t&=~32;
+
+                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 'c':
+                        fputwc(btowc(arg.i), f);
+                        l = 1;
+                        continue;
+                case 'C':
+                        fputwc(arg.i, f);
+                        l = 1;
+                        continue;
+                case 'S':
+                        a = arg.p;
+                        z = wmemchr(a, 0, p);
+                        if (z) p=z-a;
+                        if (w<p) w=p;
+                        if (!(fl&LEFT_ADJ)) fprintf(f, "%.*s", w-p, "");
+                        out(f, a, p);
+                        if ((fl&LEFT_ADJ)) fprintf(f, "%.*s", w-p, "");
+                        l=w;
+                        continue;
+                case 'm':
+                        arg.p = strerror(errno);
+                case 's':
+                        if (!arg.p) arg.p = "(null)";
+                        bs = arg.p;
+                        if (p<0) p = INT_MAX;
+                        for (i=l=0; l<p && (i=mbtowc(&wc, bs, MB_LEN_MAX))>0; bs+=i, l++);
+                        if (i<0) return -1;
+                        p=l;
+                        if (w<p) w=p;
+                        if (!(fl&LEFT_ADJ)) fprintf(f, "%.*s", w-p, "");
+                        bs = arg.p;
+                        while (l--) {
+                                i=mbtowc(&wc, bs, MB_LEN_MAX);
+                                bs+=i;
+                                fputwc(wc, f);
+                        }
+                        if ((fl&LEFT_ADJ)) fprintf(f, "%.*s", w-p, "");
+                        l=w;
+                        continue;
+                }
+
+                snprintf(charfmt, sizeof charfmt, "%%%s%s%s%s%s*.*%c%c",
+                        "#"+!(fl & ALT_FORM),
+                        "+"+!(fl & MARK_POS),
+                        "-"+!(fl & LEFT_ADJ),
+                        " "+!(fl & PAD_POS),
+                        "0"+!(fl & ZERO_PAD),
+                        sizeprefix[(t|32)-'a'], t);
+
+                switch (t|32) {
+                case 'a': case 'e': case 'f': case 'g':
+                        l = fprintf(f, charfmt, w, p, arg.f);
+                        break;
+                case 'd': case 'i': case 'o': case 'u': case 'x': case 'p':
+                        l = fprintf(f, charfmt, w, p, arg.i);
+                        break;
+                }
+        }
+
+        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 vfwprintf(FILE *restrict f, const wchar_t *restrict fmt, va_list ap)
+{
+        va_list ap2;
+        int nl_type[NL_ARGMAX] = {0};
+        union arg nl_arg[NL_ARGMAX];
+        int olderr;
+        int ret;
+
+        /* the copy allows passing va_list* even if va_list is an array */
+        va_copy(ap2, ap);
+        if (wprintf_core(0, fmt, &ap2, nl_arg, nl_type) < 0) {
+                va_end(ap2);
+                return -1;
+        }
+
+        FLOCK(f);
+        fwide(f, 1);
+        olderr = f->flags & F_ERR;
+        f->flags &= ~F_ERR;
+        ret = wprintf_core(f, fmt, &ap2, nl_arg, nl_type);
+        if (f->flags & F_ERR) ret = -1;
+        f->flags |= olderr;
+        FUNLOCK(f);
+        va_end(ap2);
+        return ret;
+}