toolchain/uClibc/patches-0.9.33.2/010-backport_sscanf_alloc.patch

   1 From 8cfb43de636faa401634340d1a18404844f9ba5a Mon Sep 17 00:00:00 2001
   2 From: Mike Frysinger <vapier@gentoo.org>
   3 Date: Sun, 6 May 2012 03:50:44 -0400
   4 Subject: [PATCH] stdio: implement assignment-allocation "m" character
   5
   6 The latest POSIX spec introduces a "m" character to allocate buffers for
   7 the user when using scanf type functions.  This is like the old glibc "a"
   8 flag, but now standardized.  With packages starting to use these, we need
   9 to implement it.
  10
  11 for example:
  12         char *s;
  13         sscanf("foo", "%ms", &s);
  14         printf("%s\n", s);
  15         free(s);
  16 This will automatically allocate storage for "s", read in "foo" to it,
  17 and then display it.
  18
  19 I'm not terribly familiar with the stdio layer, so this could be wrong.
  20 But it seems to work for me.
  21
  22 Signed-off-by: Mike Frysinger <vapier@gentoo.org>
  23 Signed-off-by: Felix Fietkau <nbd@openwrt.org>
  24 ---
  25  extra/Configs/Config.in | 13 ----------
  26  libc/stdio/_scanf.c     | 68 ++++++++++++++++++++++++++++---------------------
  27  2 files changed, 39 insertions(+), 42 deletions(-)
  28
  29 --- a/extra/Configs/Config.in
  30 +++ b/extra/Configs/Config.in
  31 @@ -1590,19 +1590,6 @@ config UCLIBC_PRINTF_SCANF_POSITIONAL_AR
  32
  33           Most people will answer 9.
  34
  35 -
  36 -config UCLIBC_HAS_SCANF_GLIBC_A_FLAG
  37 -       bool "Support glibc's 'a' flag for scanf string conversions (not implemented)"
  38 -       help
  39 -         NOTE!!!  Currently Not Implemented!!! Just A Place Holder!!  NOTE!!!
  40 -         NOTE!!!  Conflicts with an ANSI/ISO C99 scanf flag!!         NOTE!!!
  41 -
  42 -         Answer Y to enable support for glibc's 'a' flag for the scanf string
  43 -         conversions '%s', '%[', '%ls', '%l[', and '%S'.  This is used to
  44 -         auto-allocate sufficient memory to hold the data retrieved.
  45 -
  46 -         Most people will answer N.
  47 -
  48  choice
  49         prompt "Stdio buffer size"
  50         default UCLIBC_HAS_STDIO_BUFSIZ_4096
  51 --- a/libc/stdio/_scanf.c
  52 +++ b/libc/stdio/_scanf.c
  53 @@ -77,14 +77,6 @@
  54  #include <bits/uClibc_fpmax.h>
  55  #endif /* __UCLIBC_HAS_FLOATS__ */
  56
  57 -#ifdef __UCLIBC_HAS_SCANF_GLIBC_A_FLAG__
  58 -#ifdef L_vfscanf
  59 -/* only emit this once */
  60 -#warning Forcing undef of __UCLIBC_HAS_SCANF_GLIBC_A_FLAG__ until implemented!
  61 -#endif
  62 -#undef __UCLIBC_HAS_SCANF_GLIBC_A_FLAG__
  63 -#endif
  64 -
  65  #undef __STDIO_HAS_VSSCANF
  66  #if defined(__STDIO_BUFFERS) || !defined(__UCLIBC_HAS_WCHAR__) || defined(__UCLIBC_HAS_GLIBC_CUSTOM_STREAMS__)
  67  #define __STDIO_HAS_VSSCANF 1
  68 @@ -433,8 +425,9 @@ libc_hidden_def(vswscanf)
  69
  70
  71  /* float layout          0123456789012345678901  repeat n for "l[" */
  72 -#define SPEC_CHARS             "npxXoudifFeEgGaACSncs["
  73 -/*                       npxXoudif eEgG  CS cs[ */
  74 +#define SPEC_CHARS             "npxXoudifFeEgGaACSnmcs["
  75 +/*                       npxXoudif eEgG  CS  cs[ */
  76 +/* NOTE: the 'm' flag must come before any convs that support it */
  77
  78  /* NOTE: Ordering is important!  In particular, CONV_LEFTBRACKET
  79   * must immediately precede CONV_c. */
  80 @@ -444,7 +437,7 @@ enum {
  81         CONV_p,
  82         CONV_x, CONV_X, CONV_o, CONV_u, CONV_d, CONV_i,
  83         CONV_f, CONV_F, CONV_e, CONV_E, CONV_g, CONV_G, CONV_a, CONV_A,
  84 -       CONV_C, CONV_S, CONV_LEFTBRACKET, CONV_c, CONV_s, CONV_leftbracket,
  85 +       CONV_C, CONV_S, CONV_LEFTBRACKET, CONV_m, CONV_c, CONV_s, CONV_leftbracket,
  86         CONV_percent, CONV_whitespace /* not in SPEC_* and no flags */
  87  };
  88
  89 @@ -474,7 +467,7 @@ enum {
  90         FLAG_SURPRESS   =   0x10,       /* MUST BE 1ST!!  See DO_FLAGS. */
  91         FLAG_THOUSANDS  =       0x20,
  92         FLAG_I18N               =       0x40,   /* only works for d, i, u */
  93 -       FLAG_MALLOC     =   0x80,       /* only works for s, S, and [ (and l[)*/
  94 +       FLAG_MALLOC     =   0x80,       /* only works for c, s, S, and [ (and l[)*/
  95  };
  96
  97
  98 @@ -491,7 +484,7 @@ enum {
  99         /* fFeEgGaA */  (0x0c|FLAG_SURPRESS|FLAG_THOUSANDS|FLAG_I18N), \
 100         /* C */                 (   0|FLAG_SURPRESS), \
 101         /* S and l[ */  (   0|FLAG_SURPRESS|FLAG_MALLOC), \
 102 -       /* c */                 (0x04|FLAG_SURPRESS), \
 103 +       /* c */                 (0x04|FLAG_SURPRESS|FLAG_MALLOC), \
 104         /* s and [ */   (0x04|FLAG_SURPRESS|FLAG_MALLOC), \
 105  }
 106
 107 @@ -904,17 +897,17 @@ int attribute_hidden __psfs_parse_spec(r
 108                 if (*psfs->fmt == *p) {
 109                         int p_m_spec_chars = p - spec_chars;
 110
 111 -#ifdef __UCLIBC_HAS_SCANF_GLIBC_A_FLAG__
 112 -#error implement gnu a flag
 113 -                       if ((*p == 'a')
 114 -                               && ((psfs->fmt[1] == '[') || ((psfs->fmt[1]|0x20) == 's'))
 115 -                               ) {             /* Assumes ascii for 's' and 'S' test. */
 116 -                               psfs->flags |= FLAG_MALLOC;
 117 +                       if (*p == 'm' &&
 118 +                               (psfs->fmt[1] == '[' || psfs->fmt[1] == 'c' ||
 119 +                                /* Assumes ascii for 's' and 'S' test. */
 120 +                                (psfs->fmt[1] | 0x20) == 's'))
 121 +                       {
 122 +                               if (psfs->store)
 123 +                                       psfs->flags |= FLAG_MALLOC;
 124                                 ++psfs->fmt;
 125                                 ++p;
 126 -                               continue; /* The related conversions follow 'a'. */
 127 +                               continue; /* The related conversions follow 'm'. */
 128                         }
 129 -#endif /* __UCLIBC_HAS_SCANF_GLIBC_A_FLAG__ */
 130
 131                         for (p = spec_ranges; p_m_spec_chars > *p ; ++p) {}
 132                         if (((psfs->dataargtype >> 8) | psfs->flags)
 133 @@ -1265,12 +1258,6 @@ int VFSCANF (FILE *__restrict fp, const
 134                                 while (*wf && __isascii(*wf) && (b < buf + sizeof(buf) - 1)) {
 135                                         *b++ = *wf++;
 136                                 }
 137 -#ifdef __UCLIBC_HAS_SCANF_GLIBC_A_FLAG__
 138 -#error this is wrong... we need to ched in __psfs_parse_spec instead since this checks last char in buffer and conversion my have stopped before it.
 139 -                               if ((*b == 'a') && ((*wf == '[') || ((*wf|0x20) == 's'))) {
 140 -                                       goto DONE;      /* Spec was excessively long. */
 141 -                               }
 142 -#endif /* __UCLIBC_HAS_SCANF_GLIBC_A_FLAG__ */
 143                                 *b = 0;
 144                                 if (b == buf) { /* Bad conversion specifier! */
 145                                         goto DONE;
 146 @@ -1390,13 +1377,36 @@ int VFSCANF (FILE *__restrict fp, const
 147                                 }
 148
 149                                 if (psfs.conv_num == CONV_s) {
 150 +                                       /* We might have to handle the allocation ourselves */
 151 +                                       int len;
 152 +                                       /* With 'm', we actually got a pointer to a pointer */
 153 +                                       unsigned char **ptr = (void *)b;
 154 +
 155 +                                       i = 0;
 156 +                                       if (psfs.flags & FLAG_MALLOC) {
 157 +                                               len = 0;
 158 +                                               b = NULL;
 159 +                                       } else
 160 +                                               len = -1;
 161 +
 162                                         /* Yes, believe it or not, a %s conversion can store nuls. */
 163                                         while ((__scan_getc(&sc) >= 0) && !isspace(sc.cc)) {
 164                                                 zero_conversions = 0;
 165 -                                               *b = sc.cc;
 166 -                                               b += psfs.store;
 167 +                                               if (i == len) {
 168 +                                                       /* Pick a size that won't trigger a lot of
 169 +                                                        * mallocs early on ... */
 170 +                                                       len += 256;
 171 +                                                       b = realloc(b, len + 1);
 172 +                                               }
 173 +                                               b[i] = sc.cc;
 174 +                                               i += psfs.store;
 175                                                 fail = 0;
 176                                         }
 177 +
 178 +                                       if (psfs.flags & FLAG_MALLOC)
 179 +                                               *ptr = b;
 180 +                                       /* The code below takes care of terminating NUL */
 181 +                                       b += i;
 182                                 } else {
 183  #ifdef __UCLIBC_HAS_WCHAR__
 184                                         assert((psfs.conv_num == CONV_LEFTBRACKET) || \