| From 050cd6971f92c2337bc506043dfcf1395dd5d622 Mon Sep 17 00:00:00 2001 |
| From: Mike Frysinger <vapier@gentoo.org> |
| Date: Sun, 6 May 2012 03:50:44 -0400 |
| Subject: [PATCH] stdio: implement assignment-allocation "m" character |
| |
| The latest POSIX spec introduces a "m" character to allocate buffers for |
| the user when using scanf type functions. This is like the old glibc "a" |
| flag, but now standardized. With packages starting to use these, we need |
| to implement it. |
| |
| for example: |
| char *s; |
| sscanf("foo", "%ms", &s); |
| printf("%s\n", s); |
| free(s); |
| This will automatically allocate storage for "s", read in "foo" to it, |
| and then display it. |
| |
| I'm not terribly familiar with the stdio layer, so this could be wrong. |
| But it seems to work for me. |
| |
| Signed-off-by: Mike Frysinger <vapier@gentoo.org> |
| --- |
| extra/Configs/Config.in | 13 --------- |
| libc/stdio/_scanf.c | 68 +++++++++++++++++++++++++++-------------------- |
| 2 files changed, 39 insertions(+), 42 deletions(-) |
| |
| diff --git a/extra/Configs/Config.in b/extra/Configs/Config.in |
| index 1060729..c2f2fc7 100644 |
| --- a/extra/Configs/Config.in |
| +++ b/extra/Configs/Config.in |
| @@ -1590,19 +1590,6 @@ config UCLIBC_PRINTF_SCANF_POSITIONAL_ARGS |
| |
| Most people will answer 9. |
| |
| - |
| -config UCLIBC_HAS_SCANF_GLIBC_A_FLAG |
| - bool "Support glibc's 'a' flag for scanf string conversions (not implemented)" |
| - help |
| - NOTE!!! Currently Not Implemented!!! Just A Place Holder!! NOTE!!! |
| - NOTE!!! Conflicts with an ANSI/ISO C99 scanf flag!! NOTE!!! |
| - |
| - Answer Y to enable support for glibc's 'a' flag for the scanf string |
| - conversions '%s', '%[', '%ls', '%l[', and '%S'. This is used to |
| - auto-allocate sufficient memory to hold the data retrieved. |
| - |
| - Most people will answer N. |
| - |
| choice |
| prompt "Stdio buffer size" |
| default UCLIBC_HAS_STDIO_BUFSIZ_4096 |
| diff --git a/libc/stdio/_scanf.c b/libc/stdio/_scanf.c |
| index f38e72b..952853c 100644 |
| --- a/libc/stdio/_scanf.c |
| +++ b/libc/stdio/_scanf.c |
| @@ -77,14 +77,6 @@ |
| #include <bits/uClibc_fpmax.h> |
| #endif /* __UCLIBC_HAS_FLOATS__ */ |
| |
| -#ifdef __UCLIBC_HAS_SCANF_GLIBC_A_FLAG__ |
| -#ifdef L_vfscanf |
| -/* only emit this once */ |
| -#warning Forcing undef of __UCLIBC_HAS_SCANF_GLIBC_A_FLAG__ until implemented! |
| -#endif |
| -#undef __UCLIBC_HAS_SCANF_GLIBC_A_FLAG__ |
| -#endif |
| - |
| #undef __STDIO_HAS_VSSCANF |
| #if defined(__STDIO_BUFFERS) || !defined(__UCLIBC_HAS_WCHAR__) || defined(__UCLIBC_HAS_GLIBC_CUSTOM_STREAMS__) |
| #define __STDIO_HAS_VSSCANF 1 |
| @@ -433,8 +425,9 @@ libc_hidden_def(vswscanf) |
| |
| |
| /* float layout 0123456789012345678901 repeat n for "l[" */ |
| -#define SPEC_CHARS "npxXoudifFeEgGaACSncs[" |
| -/* npxXoudif eEgG CS cs[ */ |
| +#define SPEC_CHARS "npxXoudifFeEgGaACSnmcs[" |
| +/* npxXoudif eEgG CS cs[ */ |
| +/* NOTE: the 'm' flag must come before any convs that support it */ |
| |
| /* NOTE: Ordering is important! In particular, CONV_LEFTBRACKET |
| * must immediately precede CONV_c. */ |
| @@ -444,7 +437,7 @@ enum { |
| CONV_p, |
| CONV_x, CONV_X, CONV_o, CONV_u, CONV_d, CONV_i, |
| CONV_f, CONV_F, CONV_e, CONV_E, CONV_g, CONV_G, CONV_a, CONV_A, |
| - CONV_C, CONV_S, CONV_LEFTBRACKET, CONV_c, CONV_s, CONV_leftbracket, |
| + CONV_C, CONV_S, CONV_LEFTBRACKET, CONV_m, CONV_c, CONV_s, CONV_leftbracket, |
| CONV_percent, CONV_whitespace /* not in SPEC_* and no flags */ |
| }; |
| |
| @@ -474,7 +467,7 @@ enum { |
| FLAG_SURPRESS = 0x10, /* MUST BE 1ST!! See DO_FLAGS. */ |
| FLAG_THOUSANDS = 0x20, |
| FLAG_I18N = 0x40, /* only works for d, i, u */ |
| - FLAG_MALLOC = 0x80, /* only works for s, S, and [ (and l[)*/ |
| + FLAG_MALLOC = 0x80, /* only works for c, s, S, and [ (and l[)*/ |
| }; |
| |
| |
| @@ -491,7 +484,7 @@ enum { |
| /* fFeEgGaA */ (0x0c|FLAG_SURPRESS|FLAG_THOUSANDS|FLAG_I18N), \ |
| /* C */ ( 0|FLAG_SURPRESS), \ |
| /* S and l[ */ ( 0|FLAG_SURPRESS|FLAG_MALLOC), \ |
| - /* c */ (0x04|FLAG_SURPRESS), \ |
| + /* c */ (0x04|FLAG_SURPRESS|FLAG_MALLOC), \ |
| /* s and [ */ (0x04|FLAG_SURPRESS|FLAG_MALLOC), \ |
| } |
| |
| @@ -904,17 +897,17 @@ int attribute_hidden __psfs_parse_spec(register psfs_t *psfs) |
| if (*psfs->fmt == *p) { |
| int p_m_spec_chars = p - spec_chars; |
| |
| -#ifdef __UCLIBC_HAS_SCANF_GLIBC_A_FLAG__ |
| -#error implement gnu a flag |
| - if ((*p == 'a') |
| - && ((psfs->fmt[1] == '[') || ((psfs->fmt[1]|0x20) == 's')) |
| - ) { /* Assumes ascii for 's' and 'S' test. */ |
| - psfs->flags |= FLAG_MALLOC; |
| + if (*p == 'm' && |
| + (psfs->fmt[1] == '[' || psfs->fmt[1] == 'c' || |
| + /* Assumes ascii for 's' and 'S' test. */ |
| + (psfs->fmt[1] | 0x20) == 's')) |
| + { |
| + if (psfs->store) |
| + psfs->flags |= FLAG_MALLOC; |
| ++psfs->fmt; |
| ++p; |
| - continue; /* The related conversions follow 'a'. */ |
| + continue; /* The related conversions follow 'm'. */ |
| } |
| -#endif /* __UCLIBC_HAS_SCANF_GLIBC_A_FLAG__ */ |
| |
| for (p = spec_ranges; p_m_spec_chars > *p ; ++p) {} |
| if (((psfs->dataargtype >> 8) | psfs->flags) |
| @@ -1265,12 +1258,6 @@ int VFSCANF (FILE *__restrict fp, const Wchar *__restrict format, va_list arg) |
| while (*wf && __isascii(*wf) && (b < buf + sizeof(buf) - 1)) { |
| *b++ = *wf++; |
| } |
| -#ifdef __UCLIBC_HAS_SCANF_GLIBC_A_FLAG__ |
| -#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. |
| - if ((*b == 'a') && ((*wf == '[') || ((*wf|0x20) == 's'))) { |
| - goto DONE; /* Spec was excessively long. */ |
| - } |
| -#endif /* __UCLIBC_HAS_SCANF_GLIBC_A_FLAG__ */ |
| *b = 0; |
| if (b == buf) { /* Bad conversion specifier! */ |
| goto DONE; |
| @@ -1390,13 +1377,36 @@ int VFSCANF (FILE *__restrict fp, const Wchar *__restrict format, va_list arg) |
| } |
| |
| if (psfs.conv_num == CONV_s) { |
| + /* We might have to handle the allocation ourselves */ |
| + int len; |
| + /* With 'm', we actually got a pointer to a pointer */ |
| + unsigned char **ptr = (void *)b; |
| + |
| + i = 0; |
| + if (psfs.flags & FLAG_MALLOC) { |
| + len = 0; |
| + b = NULL; |
| + } else |
| + len = -1; |
| + |
| /* Yes, believe it or not, a %s conversion can store nuls. */ |
| while ((__scan_getc(&sc) >= 0) && !isspace(sc.cc)) { |
| zero_conversions = 0; |
| - *b = sc.cc; |
| - b += psfs.store; |
| + if (i == len) { |
| + /* Pick a size that won't trigger a lot of |
| + * mallocs early on ... */ |
| + len += 256; |
| + b = realloc(b, len + 1); |
| + } |
| + b[i] = sc.cc; |
| + i += psfs.store; |
| fail = 0; |
| } |
| + |
| + if (psfs.flags & FLAG_MALLOC) |
| + *ptr = b; |
| + /* The code below takes care of terminating NUL */ |
| + b += i; |
| } else { |
| #ifdef __UCLIBC_HAS_WCHAR__ |
| assert((psfs.conv_num == CONV_LEFTBRACKET) || \ |
| -- |
| 1.7.10.4 |
| |