libc/stdio/vsnprintf.c

   1 /* Copyright (C) 2004       Manuel Novoa III    <mjn3@codepoet.org>
   2  *
   3  * GNU Library General Public License (LGPL) version 2 or later.
   4  *
   5  * Dedicated to Toni.  See uClibc/DEDICATION.mjn3 for details.
   6  */
   7
   8 #include "_stdio.h"
   9 #include <stdarg.h>
  10
  11
  12 #ifdef __UCLIBC_MJN3_ONLY__
  13 #warning WISHLIST: Implement vsnprintf for non-buffered and no custom stream case.
  14 #endif /* __UCLIBC_MJN3_ONLY__ */
  15
  16 #ifdef __STDIO_BUFFERS
  17 /* NB: we can still have __USE_OLD_VFPRINTF__ defined in this case! */
  18
  19 int vsnprintf(char *__restrict buf, size_t size,
  20                           const char * __restrict format, va_list arg)
  21 {
  22         FILE f;
  23         int rv;
  24
  25 /*      __STDIO_STREAM_RESET_GCS(&f); */
  26 #ifdef __UCLIBC_HAS_GLIBC_CUSTOM_STREAMS__
  27         f.__cookie = &(f.__filedes);
  28         f.__gcs.read = NULL;
  29         f.__gcs.write = NULL;
  30         f.__gcs.seek = NULL;
  31         f.__gcs.close = NULL;
  32 #endif
  33
  34         f.__filedes = __STDIO_STREAM_FAKE_VSNPRINTF_FILEDES;
  35         f.__modeflags = (__FLAG_NARROW|__FLAG_WRITEONLY|__FLAG_WRITING);
  36
  37 #ifdef __UCLIBC_HAS_WCHAR__
  38         f.__ungot_width[0] = 0;
  39 #endif /* __UCLIBC_HAS_WCHAR__ */
  40 #ifdef __STDIO_MBSTATE
  41         __INIT_MBSTATE(&(f.__state));
  42 #endif /* __STDIO_MBSTATE */
  43
  44 #if (defined(__STDIO_BUFFERS) || defined(__USE_OLD_VFPRINTF__)) && defined(__UCLIBC_HAS_THREADS__)
  45         f.__user_locking = 1;           /* Set user locking. */
  46         STDIO_INIT_MUTEX(f.__lock);
  47 #endif
  48         f.__nextopen = NULL;
  49
  50         if (size > SIZE_MAX - (size_t) buf) {
  51                 size = SIZE_MAX - (size_t) buf;
  52         }
  53
  54 /* TODO: this comment seems to be wrong */
  55         /* Set these last since __bufputc initialization depends on
  56          * __user_locking and only gets set if user locking is on. */
  57         f.__bufstart = (unsigned char *) buf;
  58         f.__bufend = (unsigned char *) buf + size;
  59         __STDIO_STREAM_INIT_BUFREAD_BUFPOS(&f);
  60         __STDIO_STREAM_DISABLE_GETC(&f);
  61         __STDIO_STREAM_ENABLE_PUTC(&f);
  62
  63 #ifdef __USE_OLD_VFPRINTF__
  64         rv = vfprintf(&f, format, arg);
  65 #else
  66         rv = _vfprintf_internal(&f, format, arg);
  67 #endif
  68         if (size) {
  69                 if (f.__bufpos == f.__bufend) {
  70                         --f.__bufpos;
  71                 }
  72                 *f.__bufpos = 0;
  73         }
  74         return rv;
  75 }
  76 libc_hidden_def(vsnprintf)
  77
  78 #elif defined(__USE_OLD_VFPRINTF__)
  79
  80 typedef struct {
  81         FILE f;
  82         unsigned char *bufend;          /* pointer to 1 past end of buffer */
  83         unsigned char *bufpos;
  84 } __FILE_vsnprintf;
  85
  86 int vsnprintf(char *__restrict buf, size_t size,
  87                           const char * __restrict format, va_list arg)
  88 {
  89         __FILE_vsnprintf f;
  90         int rv;
  91
  92         f.bufpos = buf;
  93
  94         if (size > SIZE_MAX - (size_t) buf) {
  95                 size = SIZE_MAX - (size_t) buf;
  96         }
  97         f.bufend = buf + size;
  98
  99 /*      __STDIO_STREAM_RESET_GCS(&f.f); */
 100 #ifdef __UCLIBC_HAS_GLIBC_CUSTOM_STREAMS__
 101         f.f.__cookie = &(f.f.__filedes);
 102         f.f.__gcs.read = NULL;
 103         f.f.__gcs.write = NULL;
 104         f.f.__gcs.seek = NULL;
 105         f.f.__gcs.close = NULL;
 106 #endif
 107
 108         f.f.__filedes = __STDIO_STREAM_FAKE_VSNPRINTF_FILEDES_NB;
 109         f.f.__modeflags = (__FLAG_NARROW|__FLAG_WRITEONLY|__FLAG_WRITING);
 110
 111 #ifdef __UCLIBC_HAS_WCHAR__
 112         f.f.__ungot_width[0] = 0;
 113 #endif /* __UCLIBC_HAS_WCHAR__ */
 114 #ifdef __STDIO_MBSTATE
 115         __INIT_MBSTATE(&(f.f.__state));
 116 #endif /* __STDIO_MBSTATE */
 117
 118 #ifdef __UCLIBC_HAS_THREADS__
 119         f.f.__user_locking = 1;         /* Set user locking. */
 120         STDIO_INIT_MUTEX(f.f.__lock);
 121 #endif
 122         f.f.__nextopen = NULL;
 123
 124         rv = vfprintf((FILE *) &f, format, arg);
 125         if (size) {
 126                 if (f.bufpos == f.bufend) {
 127                         --f.bufpos;
 128                 }
 129                 *f.bufpos = 0;
 130         }
 131         return rv;
 132 }
 133 libc_hidden_def(vsnprintf)
 134
 135 #elif defined(__UCLIBC_HAS_GLIBC_CUSTOM_STREAMS__)
 136
 137 typedef struct {
 138         size_t pos;
 139         size_t len;
 140         unsigned char *buf;
 141         FILE *fp;
 142 } __snpf_cookie;
 143
 144 #define COOKIE ((__snpf_cookie *) cookie)
 145
 146 static ssize_t snpf_write(register void *cookie, const char *buf,
 147                                                   size_t bufsize)
 148 {
 149         size_t count;
 150         register char *p;
 151
 152         /* Note: bufsize < SSIZE_MAX because of _stdio_WRITE. */
 153
 154         if (COOKIE->len > COOKIE->pos) {
 155                 count = COOKIE->len - COOKIE->pos - 1; /* Leave space for nul. */
 156                 if (count > bufsize) {
 157                         count = bufsize;
 158                 }
 159
 160                 p = COOKIE->buf + COOKIE->pos;
 161                 while (count) {
 162                         *p++ = *buf++;
 163                         --count;
 164                 }
 165                 *p = 0;
 166         }
 167
 168         COOKIE->pos += bufsize;
 169
 170         return bufsize;
 171 }
 172
 173 #undef COOKIE
 174
 175 int vsnprintf(char *__restrict buf, size_t size,
 176                           const char * __restrict format, va_list arg)
 177 {
 178         FILE f;
 179         __snpf_cookie cookie;
 180         int rv;
 181
 182         cookie.buf = buf;
 183         cookie.len = size;
 184         cookie.pos = 0;
 185         cookie.fp = &f;
 186
 187         f.__cookie = &cookie;
 188         f.__gcs.write = snpf_write;
 189         f.__gcs.read = NULL;
 190         f.__gcs.seek = NULL;
 191         f.__gcs.close = NULL;
 192
 193         f.__filedes = -1;                       /* For debugging. */
 194         f.__modeflags = (__FLAG_NARROW|__FLAG_WRITEONLY|__FLAG_WRITING);
 195
 196 #ifdef __UCLIBC_HAS_WCHAR__
 197         f.__ungot_width[0] = 0;
 198 #endif /* __UCLIBC_HAS_WCHAR__ */
 199 #ifdef __STDIO_MBSTATE
 200         __INIT_MBSTATE(&(f.__state));
 201 #endif /* __STDIO_MBSTATE */
 202
 203         f.__nextopen = NULL;
 204
 205         rv = _vfprintf_internal(&f, format, arg);
 206
 207         return rv;
 208 }
 209 libc_hidden_def(vsnprintf)
 210
 211 #else
 212 #warning Skipping vsnprintf since no buffering, no custom streams, and not old vfprintf!
 213 #ifdef __STDIO_HAS_VSNPRINTF
 214 #error WHOA! __STDIO_HAS_VSNPRINTF is defined!
 215 #endif
 216 #endif