xref: /third_party/musl/src/stdio/vfwprintf.c (revision 570af302)
1#include "stdio_impl.h"
2#include <errno.h>
3#include <ctype.h>
4#include <limits.h>
5#include <string.h>
6#include <stdarg.h>
7#include <stddef.h>
8#include <stdlib.h>
9#include <wchar.h>
10#include <inttypes.h>
11
12/* Convenient bit representation for modifier flags, which all fall
13 * within 31 codepoints of the space character. */
14
15#define ALT_FORM   (1U<<'#'-' ')
16#define ZERO_PAD   (1U<<'0'-' ')
17#define LEFT_ADJ   (1U<<'-'-' ')
18#define PAD_POS    (1U<<' '-' ')
19#define MARK_POS   (1U<<'+'-' ')
20#define GROUPED    (1U<<'\''-' ')
21
22#define FLAGMASK (ALT_FORM|ZERO_PAD|LEFT_ADJ|PAD_POS|MARK_POS|GROUPED)
23
24/* State machine to accept length modifiers + conversion specifiers.
25 * Result is 0 on failure, or an argument type to pop on success. */
26
27enum {
28	BARE, LPRE, LLPRE, HPRE, HHPRE, BIGLPRE,
29	ZTPRE, JPRE,
30	STOP,
31	PTR, INT, UINT, ULLONG,
32	LONG, ULONG,
33	SHORT, USHORT, CHAR, UCHAR,
34	LLONG, SIZET, IMAX, UMAX, PDIFF, UIPTR,
35	DBL, LDBL,
36	NOARG,
37	MAXSTATE
38};
39
40#define S(x) [(x)-'A']
41
42static const unsigned char states[]['z'-'A'+1] = {
43	{ /* 0: bare types */
44		S('d') = INT, S('i') = INT,
45		S('o') = UINT, S('u') = UINT, S('x') = UINT, S('X') = UINT,
46		S('e') = DBL, S('f') = DBL, S('g') = DBL, S('a') = DBL,
47		S('E') = DBL, S('F') = DBL, S('G') = DBL, S('A') = DBL,
48		S('c') = INT, S('C') = UINT,
49		S('s') = PTR, S('S') = PTR, S('p') = UIPTR, S('n') = PTR,
50		S('m') = NOARG,
51		S('l') = LPRE, S('h') = HPRE, S('L') = BIGLPRE,
52		S('z') = ZTPRE, S('j') = JPRE, S('t') = ZTPRE,
53	}, { /* 1: l-prefixed */
54		S('d') = LONG, S('i') = LONG,
55		S('o') = ULONG, S('u') = ULONG, S('x') = ULONG, S('X') = ULONG,
56		S('e') = DBL, S('f') = DBL, S('g') = DBL, S('a') = DBL,
57		S('E') = DBL, S('F') = DBL, S('G') = DBL, S('A') = DBL,
58		S('c') = UINT, S('s') = PTR, S('n') = PTR,
59		S('l') = LLPRE,
60	}, { /* 2: ll-prefixed */
61		S('d') = LLONG, S('i') = LLONG,
62		S('o') = ULLONG, S('u') = ULLONG,
63		S('x') = ULLONG, S('X') = ULLONG,
64		S('n') = PTR,
65	}, { /* 3: h-prefixed */
66		S('d') = SHORT, S('i') = SHORT,
67		S('o') = USHORT, S('u') = USHORT,
68		S('x') = USHORT, S('X') = USHORT,
69		S('n') = PTR,
70		S('h') = HHPRE,
71	}, { /* 4: hh-prefixed */
72		S('d') = CHAR, S('i') = CHAR,
73		S('o') = UCHAR, S('u') = UCHAR,
74		S('x') = UCHAR, S('X') = UCHAR,
75		S('n') = PTR,
76	}, { /* 5: L-prefixed */
77		S('e') = LDBL, S('f') = LDBL, S('g') = LDBL, S('a') = LDBL,
78		S('E') = LDBL, S('F') = LDBL, S('G') = LDBL, S('A') = LDBL,
79		S('n') = PTR,
80	}, { /* 6: z- or t-prefixed (assumed to be same size) */
81		S('d') = PDIFF, S('i') = PDIFF,
82		S('o') = SIZET, S('u') = SIZET,
83		S('x') = SIZET, S('X') = SIZET,
84		S('n') = PTR,
85	}, { /* 7: j-prefixed */
86		S('d') = IMAX, S('i') = IMAX,
87		S('o') = UMAX, S('u') = UMAX,
88		S('x') = UMAX, S('X') = UMAX,
89		S('n') = PTR,
90	}
91};
92
93#define OOB(x) ((unsigned)(x)-'A' > 'z'-'A')
94
95union arg
96{
97	uintmax_t i;
98	long double f;
99	void *p;
100};
101
102static void pop_arg(union arg *arg, int type, va_list *ap)
103{
104	switch (type) {
105	       case PTR:	arg->p = va_arg(*ap, void *);
106	break; case INT:	arg->i = va_arg(*ap, int);
107	break; case UINT:	arg->i = va_arg(*ap, unsigned int);
108	break; case LONG:	arg->i = va_arg(*ap, long);
109	break; case ULONG:	arg->i = va_arg(*ap, unsigned long);
110	break; case ULLONG:	arg->i = va_arg(*ap, unsigned long long);
111	break; case SHORT:	arg->i = (short)va_arg(*ap, int);
112	break; case USHORT:	arg->i = (unsigned short)va_arg(*ap, int);
113	break; case CHAR:	arg->i = (signed char)va_arg(*ap, int);
114	break; case UCHAR:	arg->i = (unsigned char)va_arg(*ap, int);
115	break; case LLONG:	arg->i = va_arg(*ap, long long);
116	break; case SIZET:	arg->i = va_arg(*ap, size_t);
117	break; case IMAX:	arg->i = va_arg(*ap, intmax_t);
118	break; case UMAX:	arg->i = va_arg(*ap, uintmax_t);
119	break; case PDIFF:	arg->i = va_arg(*ap, ptrdiff_t);
120	break; case UIPTR:	arg->i = (uintptr_t)va_arg(*ap, void *);
121	break; case DBL:	arg->f = va_arg(*ap, double);
122	break; case LDBL:	arg->f = va_arg(*ap, long double);
123	}
124}
125
126static void out(FILE *f, const wchar_t *s, size_t l)
127{
128	while (l-- && !ferror(f)) fputwc(*s++, f);
129}
130
131static void pad(FILE *f, int n, int fl)
132{
133	if ((fl & LEFT_ADJ) || !n || ferror(f)) return;
134	fprintf(f, "%*s", n, "");
135}
136
137static int getint(wchar_t **s) {
138	int i;
139	for (i=0; iswdigit(**s); (*s)++) {
140		if (i > INT_MAX/10U || **s-'0' > INT_MAX-10*i) i = -1;
141		else i = 10*i + (**s-'0');
142	}
143	return i;
144}
145
146static const char sizeprefix['y'-'a'] = {
147['a'-'a']='L', ['e'-'a']='L', ['f'-'a']='L', ['g'-'a']='L',
148['d'-'a']='j', ['i'-'a']='j', ['o'-'a']='j', ['u'-'a']='j', ['x'-'a']='j',
149['p'-'a']='j'
150};
151
152static int wprintf_core(FILE *f, const wchar_t *fmt, va_list *ap, union arg *nl_arg, int *nl_type)
153{
154	wchar_t *a, *z, *s=(wchar_t *)fmt;
155	unsigned l10n=0, fl;
156	int w, p, xp;
157	union arg arg;
158	int argpos;
159	unsigned st, ps;
160	int cnt=0, l=0;
161	int i;
162	int t;
163	char *bs;
164	char charfmt[16];
165	wchar_t wc;
166
167	for (;;) {
168		/* This error is only specified for snprintf, but since it's
169		 * unspecified for other forms, do the same. Stop immediately
170		 * on overflow; otherwise %n could produce wrong results. */
171		if (l > INT_MAX - cnt) goto overflow;
172
173		/* Update output count, end loop when fmt is exhausted */
174		cnt += l;
175		if (!*s) break;
176
177		/* Handle literal text and %% format specifiers */
178		for (a=s; *s && *s!='%'; s++);
179		for (z=s; s[0]=='%' && s[1]=='%'; z++, s+=2);
180		if (z-a > INT_MAX-cnt) goto overflow;
181		l = z-a;
182		if (f) out(f, a, l);
183		if (l) continue;
184
185		if (iswdigit(s[1]) && s[2]=='$') {
186			l10n=1;
187			argpos = s[1]-'0';
188			s+=3;
189		} else {
190			argpos = -1;
191			s++;
192		}
193
194		/* Read modifier flags */
195		for (fl=0; (unsigned)*s-' '<32 && (FLAGMASK&(1U<<*s-' ')); s++)
196			fl |= 1U<<*s-' ';
197
198		/* Read field width */
199		if (*s=='*') {
200			if (iswdigit(s[1]) && s[2]=='$') {
201				l10n=1;
202				nl_type[s[1]-'0'] = INT;
203				w = nl_arg[s[1]-'0'].i;
204				s+=3;
205			} else if (!l10n) {
206				w = f ? va_arg(*ap, int) : 0;
207				s++;
208			} else goto inval;
209			if (w<0) fl|=LEFT_ADJ, w=-w;
210		} else if ((w=getint(&s))<0) goto overflow;
211
212		/* Read precision */
213		if (*s=='.' && s[1]=='*') {
214			if (isdigit(s[2]) && s[3]=='$') {
215				nl_type[s[2]-'0'] = INT;
216				p = nl_arg[s[2]-'0'].i;
217				s+=4;
218			} else if (!l10n) {
219				p = f ? va_arg(*ap, int) : 0;
220				s+=2;
221			} else goto inval;
222			xp = (p>=0);
223		} else if (*s=='.') {
224			s++;
225			p = getint(&s);
226			xp = 1;
227		} else {
228			p = -1;
229			xp = 0;
230		}
231
232		/* Format specifier state machine */
233		st=0;
234		do {
235			if (OOB(*s)) goto inval;
236			ps=st;
237			st=states[st]S(*s++);
238		} while (st-1<STOP);
239		if (!st) goto inval;
240
241		/* Check validity of argument type (nl/normal) */
242		if (st==NOARG) {
243			if (argpos>=0) goto inval;
244		} else {
245			if (argpos>=0) nl_type[argpos]=st, arg=nl_arg[argpos];
246			else if (f) pop_arg(&arg, st, ap);
247			else return 0;
248		}
249
250		if (!f) continue;
251
252		/* Do not process any new directives once in error state. */
253		if (ferror(f)) return -1;
254
255		t = s[-1];
256		if (ps && (t&15)==3) t&=~32;
257
258		switch (t) {
259		case 'n':
260			switch(ps) {
261			case BARE: *(int *)arg.p = cnt; break;
262			case LPRE: *(long *)arg.p = cnt; break;
263			case LLPRE: *(long long *)arg.p = cnt; break;
264			case HPRE: *(unsigned short *)arg.p = cnt; break;
265			case HHPRE: *(unsigned char *)arg.p = cnt; break;
266			case ZTPRE: *(size_t *)arg.p = cnt; break;
267			case JPRE: *(uintmax_t *)arg.p = cnt; break;
268			}
269			continue;
270		case 'c':
271		case 'C':
272			if (w<1) w=1;
273			pad(f, w-1, fl);
274			out(f, &(wchar_t){t=='C' ? arg.i : btowc(arg.i)}, 1);
275			pad(f, w-1, fl^LEFT_ADJ);
276			l = w;
277			continue;
278		case 'S':
279			a = arg.p;
280			z = a + wcsnlen(a, p<0 ? INT_MAX : p);
281			if (p<0 && *z) goto overflow;
282			p = z-a;
283			if (w<p) w=p;
284			pad(f, w-p, fl);
285			out(f, a, p);
286			pad(f, w-p, fl^LEFT_ADJ);
287			l=w;
288			continue;
289		case 'm':
290			arg.p = strerror(errno);
291		case 's':
292			if (!arg.p) arg.p = "(null)";
293			bs = arg.p;
294			for (i=l=0; l<(p<0?INT_MAX:p) && (i=mbtowc(&wc, bs, MB_LEN_MAX))>0; bs+=i, l++);
295			if (i<0) return -1;
296			if (p<0 && *bs) goto overflow;
297			p=l;
298			if (w<p) w=p;
299			pad(f, w-p, fl);
300			bs = arg.p;
301			while (l--) {
302				i=mbtowc(&wc, bs, MB_LEN_MAX);
303				bs+=i;
304				out(f, &wc, 1);
305			}
306			pad(f, w-p, fl^LEFT_ADJ);
307			l=w;
308			continue;
309		}
310
311		if (xp && p<0) goto overflow;
312		snprintf(charfmt, sizeof charfmt, "%%%s%s%s%s%s*.*%c%c",
313			"#"+!(fl & ALT_FORM),
314			"+"+!(fl & MARK_POS),
315			"-"+!(fl & LEFT_ADJ),
316			" "+!(fl & PAD_POS),
317			"0"+!(fl & ZERO_PAD),
318			sizeprefix[(t|32)-'a'], t);
319
320		switch (t|32) {
321		case 'a': case 'e': case 'f': case 'g':
322			l = fprintf(f, charfmt, w, p, arg.f);
323			break;
324		case 'd': case 'i': case 'o': case 'u': case 'x': case 'p':
325			l = fprintf(f, charfmt, w, p, arg.i);
326			break;
327		}
328	}
329
330	if (f) return cnt;
331	if (!l10n) return 0;
332
333	for (i=1; i<=NL_ARGMAX && nl_type[i]; i++)
334		pop_arg(nl_arg+i, nl_type[i], ap);
335	for (; i<=NL_ARGMAX && !nl_type[i]; i++);
336	if (i<=NL_ARGMAX) return -1;
337	return 1;
338
339inval:
340	errno = EINVAL;
341	return -1;
342overflow:
343	errno = EOVERFLOW;
344	return -1;
345}
346
347int vfwprintf(FILE *restrict f, const wchar_t *restrict fmt, va_list ap)
348{
349	va_list ap2;
350	int nl_type[NL_ARGMAX+1] = {0};
351	union arg nl_arg[NL_ARGMAX+1];
352	int olderr;
353	int ret;
354
355	/* the copy allows passing va_list* even if va_list is an array */
356	va_copy(ap2, ap);
357	if (wprintf_core(0, fmt, &ap2, nl_arg, nl_type) < 0) {
358		va_end(ap2);
359		return -1;
360	}
361
362	FLOCK(f);
363	fwide(f, 1);
364	olderr = f->flags & F_ERR;
365	f->flags &= ~F_ERR;
366	ret = wprintf_core(f, fmt, &ap2, nl_arg, nl_type);
367	if (ferror(f)) ret = -1;
368	f->flags |= olderr;
369	FUNLOCK(f);
370	va_end(ap2);
371	return ret;
372}
373