From 4370aa4aa75391a5e2e06bccb0919109f725ed8e Mon Sep 17 00:00:00 2001 From: Lai Jiangshan Date: Fri, 6 Mar 2009 17:21:46 +0100 Subject: vsprintf: add binary printf Impact: add new APIs for binary trace printk infrastructure vbin_printf(): write args to binary buffer, string is copied when "%s" is occurred. bstr_printf(): read from binary buffer for args and format a string [fweisbec@gmail.com: rebase] Signed-off-by: Lai Jiangshan Signed-off-by: Frederic Weisbecker Cc: Linus Torvalds LKML-Reference: <1236356510-8381-2-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar --- lib/Kconfig | 3 + lib/vsprintf.c | 442 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 445 insertions(+) (limited to 'lib') diff --git a/lib/Kconfig b/lib/Kconfig index 03c2c24b9083..97d62cf091a7 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -2,6 +2,9 @@ # Library configuration # +config BINARY_PRINTF + def_bool n + menu "Library routines" config BITREVERSE diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 0fbd0121d91d..3543bbe8b1bc 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -1058,6 +1058,448 @@ int sprintf(char * buf, const char *fmt, ...) } EXPORT_SYMBOL(sprintf); +#ifdef CONFIG_BINARY_PRINTF +/* + * bprintf service: + * vbin_printf() - VA arguments to binary data + * bstr_printf() - Binary data to text string + */ + +/** + * vbin_printf - Parse a format string and place args' binary value in a buffer + * @bin_buf: The buffer to place args' binary value + * @size: The size of the buffer(by words(32bits), not characters) + * @fmt: The format string to use + * @args: Arguments for the format string + * + * The format follows C99 vsnprintf, except %n is ignored, and its argument + * is skiped. + * + * The return value is the number of words(32bits) which would be generated for + * the given input. + * + * NOTE: + * If the return value is greater than @size, the resulting bin_buf is NOT + * valid for bstr_printf(). + */ +int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args) +{ + char *str, *end; + int qualifier; + + str = (char *)bin_buf; + end = (char *)(bin_buf + size); + +#define save_arg(type) \ +do { \ + if (sizeof(type) == 8) { \ + unsigned long long value; \ + str = PTR_ALIGN(str, sizeof(u32)); \ + value = va_arg(args, unsigned long long); \ + if (str + sizeof(type) <= end) { \ + *(u32 *)str = *(u32 *)&value; \ + *(u32 *)(str + 4) = *((u32 *)&value + 1); \ + } \ + } else { \ + unsigned long value; \ + str = PTR_ALIGN(str, sizeof(type)); \ + value = va_arg(args, int); \ + if (str + sizeof(type) <= end) \ + *(typeof(type) *)str = (type)value; \ + } \ + str += sizeof(type); \ +} while (0) + + for (; *fmt ; ++fmt) { + if (*fmt != '%') + continue; + +repeat: + /* parse flags */ + ++fmt; /* this also skips first '%' */ + if (*fmt == '-' || *fmt == '+' || *fmt == ' ' + || *fmt == '#' || *fmt == '0') + goto repeat; + + /* parse field width */ + if (isdigit(*fmt)) + skip_atoi(&fmt); + else if (*fmt == '*') { + ++fmt; + /* it's the next argument */ + save_arg(int); + } + + /* parse the precision */ + if (*fmt == '.') { + ++fmt; + if (isdigit(*fmt)) + skip_atoi(&fmt); + else if (*fmt == '*') { + ++fmt; + /* it's the next argument */ + save_arg(int); + } + } + + /* parse the conversion qualifier */ + qualifier = -1; + if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' || + *fmt == 'Z' || *fmt == 'z' || *fmt == 't') { + qualifier = *fmt; + ++fmt; + if (qualifier == 'l' && *fmt == 'l') { + qualifier = 'L'; + ++fmt; + } + } + + /* parse format type */ + switch (*fmt) { + case 'c': + save_arg(char); + continue; + case 's': { + /* save the string argument */ + const char *save_str = va_arg(args, char *); + size_t len; + if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE + || (unsigned long)save_str < PAGE_SIZE) + save_str = ""; + len = strlen(save_str); + if (str + len + 1 < end) + memcpy(str, save_str, len + 1); + str += len + 1; + continue; + } + case 'p': + save_arg(void *); + /* skip all alphanumeric pointer suffixes */ + while (isalnum(fmt[1])) + fmt++; + continue; + case 'n': { + /* skip %n 's argument */ + void *skip_arg; + if (qualifier == 'l') + skip_arg = va_arg(args, long *); + else if (qualifier == 'Z' || qualifier == 'z') + skip_arg = va_arg(args, size_t *); + else + skip_arg = va_arg(args, int *); + continue; + } + case 'o': + case 'x': + case 'X': + case 'd': + case 'i': + case 'u': + /* save arg for case: 'o', 'x', 'X', 'd', 'i', 'u' */ + if (qualifier == 'L') + save_arg(long long); + else if (qualifier == 'l') + save_arg(unsigned long); + else if (qualifier == 'Z' || qualifier == 'z') + save_arg(size_t); + else if (qualifier == 't') + save_arg(ptrdiff_t); + else if (qualifier == 'h') + save_arg(short); + else + save_arg(int); + continue; + default: + if (!*fmt) + --fmt; + continue; + } + } +#undef save_arg + + return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf; +} +EXPORT_SYMBOL_GPL(vbin_printf); + +/** + * bstr_printf - Format a string from binary arguments and place it in a buffer + * @buf: The buffer to place the result into + * @size: The size of the buffer, including the trailing null space + * @fmt: The format string to use + * @bin_buf: Binary arguments for the format string + * + * This function like C99 vsnprintf, but the difference is that vsnprintf gets + * arguments from stack, and bstr_printf gets arguments from @bin_buf which is + * a binary buffer that generated by vbin_printf. + * + * The format follows C99 vsnprintf, but has some extensions: + * %pS output the name of a text symbol + * %pF output the name of a function pointer + * %pR output the address range in a struct resource + * %n is ignored + * + * The return value is the number of characters which would + * be generated for the given input, excluding the trailing + * '\0', as per ISO C99. If you want to have the exact + * number of characters written into @buf as return value + * (not including the trailing '\0'), use vscnprintf(). If the + * return is greater than or equal to @size, the resulting + * string is truncated. + */ +int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf) +{ + unsigned long long num; + int base; + char *str, *end, c; + const char *args = (const char *)bin_buf; + + int flags; + int field_width; + int precision; + int qualifier; + + if (unlikely((int) size < 0)) { + /* There can be only one.. */ + static char warn = 1; + WARN_ON(warn); + warn = 0; + return 0; + } + + str = buf; + end = buf + size; + +#define get_arg(type) \ +({ \ + typeof(type) value; \ + if (sizeof(type) == 8) { \ + args = PTR_ALIGN(args, sizeof(u32)); \ + *(u32 *)&value = *(u32 *)args; \ + *((u32 *)&value + 1) = *(u32 *)(args + 4); \ + } else { \ + args = PTR_ALIGN(args, sizeof(type)); \ + value = *(typeof(type) *)args; \ + } \ + args += sizeof(type); \ + value; \ +}) + + /* Make sure end is always >= buf */ + if (end < buf) { + end = ((void *)-1); + size = end - buf; + } + + for (; *fmt ; ++fmt) { + if (*fmt != '%') { + if (str < end) + *str = *fmt; + ++str; + continue; + } + + /* process flags */ + flags = 0; +repeat: + ++fmt; /* this also skips first '%' */ + switch (*fmt) { + case '-': + flags |= LEFT; + goto repeat; + case '+': + flags |= PLUS; + goto repeat; + case ' ': + flags |= SPACE; + goto repeat; + case '#': + flags |= SPECIAL; + goto repeat; + case '0': + flags |= ZEROPAD; + goto repeat; + } + + /* get field width */ + field_width = -1; + if (isdigit(*fmt)) + field_width = skip_atoi(&fmt); + else if (*fmt == '*') { + ++fmt; + /* it's the next argument */ + field_width = get_arg(int); + if (field_width < 0) { + field_width = -field_width; + flags |= LEFT; + } + } + + /* get the precision */ + precision = -1; + if (*fmt == '.') { + ++fmt; + if (isdigit(*fmt)) + precision = skip_atoi(&fmt); + else if (*fmt == '*') { + ++fmt; + /* it's the next argument */ + precision = get_arg(int); + } + if (precision < 0) + precision = 0; + } + + /* get the conversion qualifier */ + qualifier = -1; + if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' || + *fmt == 'Z' || *fmt == 'z' || *fmt == 't') { + qualifier = *fmt; + ++fmt; + if (qualifier == 'l' && *fmt == 'l') { + qualifier = 'L'; + ++fmt; + } + } + + /* default base */ + base = 10; + + switch (*fmt) { + case 'c': + if (!(flags & LEFT)) { + while (--field_width > 0) { + if (str < end) + *str = ' '; + ++str; + } + } + c = (unsigned char) get_arg(char); + if (str < end) + *str = c; + ++str; + while (--field_width > 0) { + if (str < end) + *str = ' '; + ++str; + } + continue; + + case 's':{ + const char *str_arg = args; + size_t len = strlen(str_arg); + args += len + 1; + str = string(str, end, (char *)str_arg, field_width, + precision, flags); + continue; + } + + case 'p': + str = pointer(fmt+1, str, end, get_arg(void *), + field_width, precision, flags); + /* Skip all alphanumeric pointer suffixes */ + while (isalnum(fmt[1])) + fmt++; + continue; + + case 'n': + /* skip %n */ + continue; + + case '%': + if (str < end) + *str = '%'; + ++str; + continue; + + /* integer number formats - set up the flags and "break" */ + case 'o': + base = 8; + break; + + case 'x': + flags |= SMALL; + case 'X': + base = 16; + break; + + case 'd': + case 'i': + flags |= SIGN; + case 'u': + break; + + default: + if (str < end) + *str = '%'; + ++str; + if (*fmt) { + if (str < end) + *str = *fmt; + ++str; + } else { + --fmt; + } + continue; + } + if (qualifier == 'L') + num = get_arg(long long); + else if (qualifier == 'l') { + num = get_arg(unsigned long); + if (flags & SIGN) + num = (signed long) num; + } else if (qualifier == 'Z' || qualifier == 'z') { + num = get_arg(size_t); + } else if (qualifier == 't') { + num = get_arg(ptrdiff_t); + } else if (qualifier == 'h') { + num = (unsigned short) get_arg(short); + if (flags & SIGN) + num = (signed short) num; + } else { + num = get_arg(unsigned int); + if (flags & SIGN) + num = (signed int) num; + } + str = number(str, end, num, base, + field_width, precision, flags); + } + if (size > 0) { + if (str < end) + *str = '\0'; + else + end[-1] = '\0'; + } +#undef get_arg + + /* the trailing null byte doesn't count towards the total */ + return str - buf; +} +EXPORT_SYMBOL_GPL(bstr_printf); + +/** + * bprintf - Parse a format string and place args' binary value in a buffer + * @bin_buf: The buffer to place args' binary value + * @size: The size of the buffer(by words(32bits), not characters) + * @fmt: The format string to use + * @...: Arguments for the format string + * + * The function returns the number of words(u32) written + * into @bin_buf. + */ +int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) +{ + va_list args; + int ret; + + va_start(args, fmt); + ret = vbin_printf(bin_buf, size, fmt, args); + va_end(args); + return ret; +} +EXPORT_SYMBOL_GPL(bprintf); + +#endif /* CONFIG_BINARY_PRINTF */ + /** * vsscanf - Unformat a buffer into a list of arguments * @buf: input buffer -- cgit v1.2.3 From fef20d9c1380f04ba9492d6463148db07b413708 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Fri, 6 Mar 2009 17:21:50 +0100 Subject: vsprintf: unify the format decoding layer for its 3 users An new optimization is making its way to ftrace. Its purpose is to make trace_printk() consuming less memory and be faster. Written by Lai Jiangshan, the approach is to delay the formatting job from tracing time to output time. Currently, a call to trace_printk() will format the whole string and insert it into the ring buffer. Then you can read it on /debug/tracing/trace file. The new implementation stores the address of the format string and the binary parameters into the ring buffer, making the packet more compact and faster to insert. Later, when the user exports the traces, the format string is retrieved with the binary parameters and the formatting job is eventually done. The new implementation rewrites a lot of format decoding bits from vsnprintf() function, making now 3 differents functions to maintain in their duplicated parts of printf format decoding bits. Suggested by Ingo Molnar, this patch tries to factorize the most possible common bits from these functions. The real common part between them is the format decoding. Although they do somewhat similar jobs, their way to export or import the parameters is very different. Thus, only the decoding layer is extracted, unless you see other parts that could be worth factorized. Changes in V2: - Address a suggestion from Linus to group the format_decode() parameters inside a structure. Changes in v3: - Address other cleanups suggested by Ingo and Linus such as passing the printf_spec struct to the format helpers: pointer()/number()/string() Note that this struct is passed by copy and not by address. This is to avoid side effects because these functions often change these values and the changes shoudn't be persistant when a callee helper returns. It would be too risky. - Various cleanups (code alignement, switch/case instead of if/else fountains). - Fix a bug that printed the first format specifier following a %p Changes in v4: - drop unapropriate const qualifier loss while casting fmt to a char * (thanks to Vegard Nossum for having pointed this out). Signed-off-by: Frederic Weisbecker Cc: Linus Torvalds Acked-by: Steven Rostedt LKML-Reference: <1236356510-8381-6-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar --- lib/vsprintf.c | 972 ++++++++++++++++++++++++++++++++------------------------- 1 file changed, 541 insertions(+), 431 deletions(-) (limited to 'lib') diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 3543bbe8b1bc..25f01578c856 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -396,7 +396,38 @@ static noinline char* put_dec(char *buf, unsigned long long num) #define SMALL 32 /* Must be 32 == 0x20 */ #define SPECIAL 64 /* 0x */ -static char *number(char *buf, char *end, unsigned long long num, int base, int size, int precision, int type) +enum format_type { + FORMAT_TYPE_NONE, /* Just a string part */ + FORMAT_TYPE_WITDH, + FORMAT_TYPE_PRECISION, + FORMAT_TYPE_CHAR, + FORMAT_TYPE_STR, + FORMAT_TYPE_PTR, + FORMAT_TYPE_PERCENT_CHAR, + FORMAT_TYPE_INVALID, + FORMAT_TYPE_LONG_LONG, + FORMAT_TYPE_ULONG, + FORMAT_TYPE_LONG, + FORMAT_TYPE_USHORT, + FORMAT_TYPE_SHORT, + FORMAT_TYPE_UINT, + FORMAT_TYPE_INT, + FORMAT_TYPE_NRCHARS, + FORMAT_TYPE_SIZE_T, + FORMAT_TYPE_PTRDIFF +}; + +struct printf_spec { + enum format_type type; + int flags; /* flags to number() */ + int field_width; /* width of output field */ + int base; + int precision; /* # of digits/chars */ + int qualifier; +}; + +static char *number(char *buf, char *end, unsigned long long num, + struct printf_spec spec) { /* we are called with base 8, 10 or 16, only, thus don't need "G..." */ static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */ @@ -404,32 +435,32 @@ static char *number(char *buf, char *end, unsigned long long num, int base, int char tmp[66]; char sign; char locase; - int need_pfx = ((type & SPECIAL) && base != 10); + int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10); int i; /* locase = 0 or 0x20. ORing digits or letters with 'locase' * produces same digits or (maybe lowercased) letters */ - locase = (type & SMALL); - if (type & LEFT) - type &= ~ZEROPAD; + locase = (spec.flags & SMALL); + if (spec.flags & LEFT) + spec.flags &= ~ZEROPAD; sign = 0; - if (type & SIGN) { + if (spec.flags & SIGN) { if ((signed long long) num < 0) { sign = '-'; num = - (signed long long) num; - size--; - } else if (type & PLUS) { + spec.field_width--; + } else if (spec.flags & PLUS) { sign = '+'; - size--; - } else if (type & SPACE) { + spec.field_width--; + } else if (spec.flags & SPACE) { sign = ' '; - size--; + spec.field_width--; } } if (need_pfx) { - size--; - if (base == 16) - size--; + spec.field_width--; + if (spec.base == 16) + spec.field_width--; } /* generate full string in tmp[], in reverse order */ @@ -441,10 +472,10 @@ static char *number(char *buf, char *end, unsigned long long num, int base, int tmp[i++] = (digits[do_div(num,base)] | locase); } while (num != 0); */ - else if (base != 10) { /* 8 or 16 */ - int mask = base - 1; + else if (spec.base != 10) { /* 8 or 16 */ + int mask = spec.base - 1; int shift = 3; - if (base == 16) shift = 4; + if (spec.base == 16) shift = 4; do { tmp[i++] = (digits[((unsigned char)num) & mask] | locase); num >>= shift; @@ -454,12 +485,12 @@ static char *number(char *buf, char *end, unsigned long long num, int base, int } /* printing 100 using %2d gives "100", not "00" */ - if (i > precision) - precision = i; + if (i > spec.precision) + spec.precision = i; /* leading space padding */ - size -= precision; - if (!(type & (ZEROPAD+LEFT))) { - while(--size >= 0) { + spec.field_width -= spec.precision; + if (!(spec.flags & (ZEROPAD+LEFT))) { + while(--spec.field_width >= 0) { if (buf < end) *buf = ' '; ++buf; @@ -476,23 +507,23 @@ static char *number(char *buf, char *end, unsigned long long num, int base, int if (buf < end) *buf = '0'; ++buf; - if (base == 16) { + if (spec.base == 16) { if (buf < end) *buf = ('X' | locase); ++buf; } } /* zero or space padding */ - if (!(type & LEFT)) { - char c = (type & ZEROPAD) ? '0' : ' '; - while (--size >= 0) { + if (!(spec.flags & LEFT)) { + char c = (spec.flags & ZEROPAD) ? '0' : ' '; + while (--spec.field_width >= 0) { if (buf < end) *buf = c; ++buf; } } /* hmm even more zero padding? */ - while (i <= --precision) { + while (i <= --spec.precision) { if (buf < end) *buf = '0'; ++buf; @@ -504,7 +535,7 @@ static char *number(char *buf, char *end, unsigned long long num, int base, int ++buf; } /* trailing space padding */ - while (--size >= 0) { + while (--spec.field_width >= 0) { if (buf < end) *buf = ' '; ++buf; @@ -512,17 +543,17 @@ static char *number(char *buf, char *end, unsigned long long num, int base, int return buf; } -static char *string(char *buf, char *end, char *s, int field_width, int precision, int flags) +static char *string(char *buf, char *end, char *s, struct printf_spec spec) { int len, i; if ((unsigned long)s < PAGE_SIZE) s = ""; - len = strnlen(s, precision); + len = strnlen(s, spec.precision); - if (!(flags & LEFT)) { - while (len < field_width--) { + if (!(spec.flags & LEFT)) { + while (len < spec.field_width--) { if (buf < end) *buf = ' '; ++buf; @@ -533,7 +564,7 @@ static char *string(char *buf, char *end, char *s, int field_width, int precisio *buf = *s; ++buf; ++s; } - while (len < field_width--) { + while (len < spec.field_width--) { if (buf < end) *buf = ' '; ++buf; @@ -541,21 +572,24 @@ static char *string(char *buf, char *end, char *s, int field_width, int precisio return buf; } -static char *symbol_string(char *buf, char *end, void *ptr, int field_width, int precision, int flags) +static char *symbol_string(char *buf, char *end, void *ptr, + struct printf_spec spec) { unsigned long value = (unsigned long) ptr; #ifdef CONFIG_KALLSYMS char sym[KSYM_SYMBOL_LEN]; sprint_symbol(sym, value); - return string(buf, end, sym, field_width, precision, flags); + return string(buf, end, sym, spec); #else - field_width = 2*sizeof(void *); - flags |= SPECIAL | SMALL | ZEROPAD; - return number(buf, end, value, 16, field_width, precision, flags); + spec.field_width = 2*sizeof(void *); + spec.flags |= SPECIAL | SMALL | ZEROPAD; + spec.base = 16; + return number(buf, end, value, spec); #endif } -static char *resource_string(char *buf, char *end, struct resource *res, int field_width, int precision, int flags) +static char *resource_string(char *buf, char *end, struct resource *res, + struct printf_spec spec) { #ifndef IO_RSRC_PRINTK_SIZE #define IO_RSRC_PRINTK_SIZE 4 @@ -564,7 +598,11 @@ static char *resource_string(char *buf, char *end, struct resource *res, int fie #ifndef MEM_RSRC_PRINTK_SIZE #define MEM_RSRC_PRINTK_SIZE 8 #endif - + struct printf_spec num_spec = { + .base = 16, + .precision = -1, + .flags = SPECIAL | SMALL | ZEROPAD, + }; /* room for the actual numbers, the two "0x", -, [, ] and the final zero */ char sym[4*sizeof(resource_size_t) + 8]; char *p = sym, *pend = sym + sizeof(sym); @@ -576,17 +614,18 @@ static char *resource_string(char *buf, char *end, struct resource *res, int fie size = MEM_RSRC_PRINTK_SIZE; *p++ = '['; - p = number(p, pend, res->start, 16, size, -1, SPECIAL | SMALL | ZEROPAD); + num_spec.field_width = size; + p = number(p, pend, res->start, num_spec); *p++ = '-'; - p = number(p, pend, res->end, 16, size, -1, SPECIAL | SMALL | ZEROPAD); + p = number(p, pend, res->end, num_spec); *p++ = ']'; *p = 0; - return string(buf, end, sym, field_width, precision, flags); + return string(buf, end, sym, spec); } -static char *mac_address_string(char *buf, char *end, u8 *addr, int field_width, - int precision, int flags) +static char *mac_address_string(char *buf, char *end, u8 *addr, + struct printf_spec spec) { char mac_addr[6 * 3]; /* (6 * 2 hex digits), 5 colons and trailing zero */ char *p = mac_addr; @@ -594,16 +633,17 @@ static char *mac_address_string(char *buf, char *end, u8 *addr, int field_width, for (i = 0; i < 6; i++) { p = pack_hex_byte(p, addr[i]); - if (!(flags & SPECIAL) && i != 5) + if (!(spec.flags & SPECIAL) && i != 5) *p++ = ':'; } *p = '\0'; + spec.flags &= ~SPECIAL; - return string(buf, end, mac_addr, field_width, precision, flags & ~SPECIAL); + return string(buf, end, mac_addr, spec); } -static char *ip6_addr_string(char *buf, char *end, u8 *addr, int field_width, - int precision, int flags) +static char *ip6_addr_string(char *buf, char *end, u8 *addr, + struct printf_spec spec) { char ip6_addr[8 * 5]; /* (8 * 4 hex digits), 7 colons and trailing zero */ char *p = ip6_addr; @@ -612,16 +652,17 @@ static char *ip6_addr_string(char *buf, char *end, u8 *addr, int field_width, for (i = 0; i < 8; i++) { p = pack_hex_byte(p, addr[2 * i]); p = pack_hex_byte(p, addr[2 * i + 1]); - if (!(flags & SPECIAL) && i != 7) + if (!(spec.flags & SPECIAL) && i != 7) *p++ = ':'; } *p = '\0'; + spec.flags &= ~SPECIAL; - return string(buf, end, ip6_addr, field_width, precision, flags & ~SPECIAL); + return string(buf, end, ip6_addr, spec); } -static char *ip4_addr_string(char *buf, char *end, u8 *addr, int field_width, - int precision, int flags) +static char *ip4_addr_string(char *buf, char *end, u8 *addr, + struct printf_spec spec) { char ip4_addr[4 * 4]; /* (4 * 3 decimal digits), 3 dots and trailing zero */ char temp[3]; /* hold each IP quad in reverse order */ @@ -637,8 +678,9 @@ static char *ip4_addr_string(char *buf, char *end, u8 *addr, int field_width, *p++ = '.'; } *p = '\0'; + spec.flags &= ~SPECIAL; - return string(buf, end, ip4_addr, field_width, precision, flags & ~SPECIAL); + return string(buf, end, ip4_addr, spec); } /* @@ -663,41 +705,234 @@ static char *ip4_addr_string(char *buf, char *end, u8 *addr, int field_width, * function pointers are really function descriptors, which contain a * pointer to the real address. */ -static char *pointer(const char *fmt, char *buf, char *end, void *ptr, int field_width, int precision, int flags) +static char *pointer(const char *fmt, char *buf, char *end, void *ptr, + struct printf_spec spec) { if (!ptr) - return string(buf, end, "(null)", field_width, precision, flags); + return string(buf, end, "(null)", spec); switch (*fmt) { case 'F': ptr = dereference_function_descriptor(ptr); /* Fallthrough */ case 'S': - return symbol_string(buf, end, ptr, field_width, precision, flags); + return symbol_string(buf, end, ptr, spec); case 'R': - return resource_string(buf, end, ptr, field_width, precision, flags); + return resource_string(buf, end, ptr, spec); case 'm': - flags |= SPECIAL; + spec.flags |= SPECIAL; /* Fallthrough */ case 'M': - return mac_address_string(buf, end, ptr, field_width, precision, flags); + return mac_address_string(buf, end, ptr, spec); case 'i': - flags |= SPECIAL; + spec.flags |= SPECIAL; /* Fallthrough */ case 'I': if (fmt[1] == '6') - return ip6_addr_string(buf, end, ptr, field_width, precision, flags); + return ip6_addr_string(buf, end, ptr, spec); if (fmt[1] == '4') - return ip4_addr_string(buf, end, ptr, field_width, precision, flags); - flags &= ~SPECIAL; + return ip4_addr_string(buf, end, ptr, spec); + spec.flags &= ~SPECIAL; + break; + } + spec.flags |= SMALL; + if (spec.field_width == -1) { + spec.field_width = 2*sizeof(void *); + spec.flags |= ZEROPAD; + } + spec.base = 16; + + return number(buf, end, (unsigned long) ptr, spec); +} + +/* + * Helper function to decode printf style format. + * Each call decode a token from the format and return the + * number of characters read (or likely the delta where it wants + * to go on the next call). + * The decoded token is returned through the parameters + * + * 'h', 'l', or 'L' for integer fields + * 'z' support added 23/7/1999 S.H. + * 'z' changed to 'Z' --davidm 1/25/99 + * 't' added for ptrdiff_t + * + * @fmt: the format string + * @type of the token returned + * @flags: various flags such as +, -, # tokens.. + * @field_width: overwritten width + * @base: base of the number (octal, hex, ...) + * @precision: precision of a number + * @qualifier: qualifier of a number (long, size_t, ...) + */ +static int format_decode(const char *fmt, struct printf_spec *spec) +{ + const char *start = fmt; + bool sign = false; + + /* we finished early by reading the field width */ + if (spec->type == FORMAT_TYPE_WITDH) { + if (spec->field_width < 0) { + spec->field_width = -spec->field_width; + spec->flags |= LEFT; + } + spec->type = FORMAT_TYPE_NONE; + goto precision; + } + + /* we finished early by reading the precision */ + if (spec->type == FORMAT_TYPE_PRECISION) { + if (spec->precision < 0) + spec->precision = 0; + + spec->type = FORMAT_TYPE_NONE; + goto qualifier; + } + + /* By default */ + spec->type = FORMAT_TYPE_NONE; + + for (; *fmt ; ++fmt) { + if (*fmt == '%') + break; + } + + /* Return the current non-format string */ + if (fmt != start || !*fmt) + return fmt - start; + + /* Process flags */ + spec->flags = 0; + + while (1) { /* this also skips first '%' */ + bool found = true; + + ++fmt; + + switch (*fmt) { + case '-': spec->flags |= LEFT; break; + case '+': spec->flags |= PLUS; break; + case ' ': spec->flags |= SPACE; break; + case '#': spec->flags |= SPECIAL; break; + case '0': spec->flags |= ZEROPAD; break; + default: found = false; + } + + if (!found) + break; + } + + /* get field width */ + spec->field_width = -1; + + if (isdigit(*fmt)) + spec->field_width = skip_atoi(&fmt); + else if (*fmt == '*') { + /* it's the next argument */ + spec->type = FORMAT_TYPE_WITDH; + return ++fmt - start; + } + +precision: + /* get the precision */ + spec->precision = -1; + if (*fmt == '.') { + ++fmt; + if (isdigit(*fmt)) { + spec->precision = skip_atoi(&fmt); + if (spec->precision < 0) + spec->precision = 0; + } else if (*fmt == '*') { + /* it's the next argument */ + spec->type = FORMAT_TYPE_WITDH; + return ++fmt - start; + } + } + +qualifier: + /* get the conversion qualifier */ + spec->qualifier = -1; + if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' || + *fmt == 'Z' || *fmt == 'z' || *fmt == 't') { + spec->qualifier = *fmt; + ++fmt; + if (spec->qualifier == 'l' && *fmt == 'l') { + spec->qualifier = 'L'; + ++fmt; + } + } + + /* default base */ + spec->base = 10; + switch (*fmt) { + case 'c': + spec->type = FORMAT_TYPE_CHAR; + return ++fmt - start; + + case 's': + spec->type = FORMAT_TYPE_STR; + return ++fmt - start; + + case 'p': + spec->type = FORMAT_TYPE_PTR; + return fmt - start; + /* skip alnum */ + + case 'n': + spec->type = FORMAT_TYPE_NRCHARS; + return ++fmt - start; + + case '%': + spec->type = FORMAT_TYPE_PERCENT_CHAR; + return ++fmt - start; + + /* integer number formats - set up the flags and "break" */ + case 'o': + spec->base = 8; break; + + case 'x': + spec->flags |= SMALL; + + case 'X': + spec->base = 16; + break; + + case 'd': + case 'i': + sign = true; + case 'u': + break; + + default: + spec->type = FORMAT_TYPE_INVALID; + return fmt - start; } - flags |= SMALL; - if (field_width == -1) { - field_width = 2*sizeof(void *); - flags |= ZEROPAD; + + if (spec->qualifier == 'L') + spec->type = FORMAT_TYPE_LONG_LONG; + else if (spec->qualifier == 'l') { + if (sign) + spec->type = FORMAT_TYPE_LONG; + else + spec->type = FORMAT_TYPE_ULONG; + } else if (spec->qualifier == 'Z' || spec->qualifier == 'z') { + spec->type = FORMAT_TYPE_SIZE_T; + } else if (spec->qualifier == 't') { + spec->type = FORMAT_TYPE_PTRDIFF; + } else if (spec->qualifier == 'h') { + if (sign) + spec->type = FORMAT_TYPE_SHORT; + else + spec->type = FORMAT_TYPE_USHORT; + } else { + if (sign) + spec->type = FORMAT_TYPE_INT; + else + spec->type = FORMAT_TYPE_UINT; } - return number(buf, end, (unsigned long) ptr, 16, field_width, precision, flags); + + return ++fmt - start; } /** @@ -726,18 +961,9 @@ static char *pointer(const char *fmt, char *buf, char *end, void *ptr, int field int vsnprintf(char *buf, size_t size, const char *fmt, va_list args) { unsigned long long num; - int base; char *str, *end, c; - - int flags; /* flags to number() */ - - int field_width; /* width of output field */ - int precision; /* min. # of digits for integers; max - number of chars for from string */ - int qualifier; /* 'h', 'l', or 'L' for integer fields */ - /* 'z' support added 23/7/1999 S.H. */ - /* 'z' changed to 'Z' --davidm 1/25/99 */ - /* 't' added for ptrdiff_t */ + int read; + struct printf_spec spec = {0}; /* Reject out-of-range values early. Large positive sizes are used for unknown buffer sizes. */ @@ -758,184 +984,144 @@ int vsnprintf(char *buf, size_t size, const char *fmt, va_list args) size = end - buf; } - for (; *fmt ; ++fmt) { - if (*fmt != '%') { - if (str < end) - *str = *fmt; - ++str; - continue; - } + while (*fmt) { + const char *old_fmt = fmt; - /* process flags */ - flags = 0; - repeat: - ++fmt; /* this also skips first '%' */ - switch (*fmt) { - case '-': flags |= LEFT; goto repeat; - case '+': flags |= PLUS; goto repeat; - case ' ': flags |= SPACE; goto repeat; - case '#': flags |= SPECIAL; goto repeat; - case '0': flags |= ZEROPAD; goto repeat; - } + read = format_decode(fmt, &spec); - /* get field width */ - field_width = -1; - if (isdigit(*fmt)) - field_width = skip_atoi(&fmt); - else if (*fmt == '*') { - ++fmt; - /* it's the next argument */ - field_width = va_arg(args, int); - if (field_width < 0) { - field_width = -field_width; - flags |= LEFT; - } - } + fmt += read; - /* get the precision */ - precision = -1; - if (*fmt == '.') { - ++fmt; - if (isdigit(*fmt)) - precision = skip_atoi(&fmt); - else if (*fmt == '*') { - ++fmt; - /* it's the next argument */ - precision = va_arg(args, int); + switch (spec.type) { + case FORMAT_TYPE_NONE: { + int copy = read; + if (str < end) { + if (copy > end - str) + copy = end - str; + memcpy(str, old_fmt, copy); } - if (precision < 0) - precision = 0; + str += read; + break; } - /* get the conversion qualifier */ - qualifier = -1; - if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' || - *fmt =='Z' || *fmt == 'z' || *fmt == 't') { - qualifier = *fmt; - ++fmt; - if (qualifier == 'l' && *fmt == 'l') { - qualifier = 'L'; - ++fmt; - } - } + case FORMAT_TYPE_WITDH: + spec.field_width = va_arg(args, int); + break; - /* default base */ - base = 10; + case FORMAT_TYPE_PRECISION: + spec.precision = va_arg(args, int); + break; - switch (*fmt) { - case 'c': - if (!(flags & LEFT)) { - while (--field_width > 0) { - if (str < end) - *str = ' '; - ++str; - } - } - c = (unsigned char) va_arg(args, int); - if (str < end) - *str = c; - ++str; - while (--field_width > 0) { + case FORMAT_TYPE_CHAR: + if (!(spec.flags & LEFT)) { + while (--spec.field_width > 0) { if (str < end) *str = ' '; ++str; - } - continue; - - case 's': - str = string(str, end, va_arg(args, char *), field_width, precision, flags); - continue; - - case 'p': - str = pointer(fmt+1, str, end, - va_arg(args, void *), - field_width, precision, flags); - /* Skip all alphanumeric pointer suffixes */ - while (isalnum(fmt[1])) - fmt++; - continue; - - case 'n': - /* FIXME: - * What does C99 say about the overflow case here? */ - if (qualifier == 'l') { - long * ip = va_arg(args, long *); - *ip = (str - buf); - } else if (qualifier == 'Z' || qualifier == 'z') { - size_t * ip = va_arg(args, size_t *); - *ip = (str - buf); - } else { - int * ip = va_arg(args, int *); - *ip = (str - buf); - } - continue; - case '%': + } + } + c = (unsigned char) va_arg(args, int); + if (str < end) + *str = c; + ++str; + while (--spec.field_width > 0) { if (str < end) - *str = '%'; + *str = ' '; ++str; - continue; + } + break; - /* integer number formats - set up the flags and "break" */ - case 'o': - base = 8; - break; + case FORMAT_TYPE_STR: + str = string(str, end, va_arg(args, char *), spec); + break; - case 'x': - flags |= SMALL; - case 'X': - base = 16; - break; + case FORMAT_TYPE_PTR: + str = pointer(fmt+1, str, end, va_arg(args, void *), + spec); + while (isalnum(*fmt)) + fmt++; + break; - case 'd': - case 'i': - flags |= SIGN; - case 'u': - break; + case FORMAT_TYPE_PERCENT_CHAR: + if (str < end) + *str = '%'; + ++str; + break; - default: + case FORMAT_TYPE_INVALID: + if (str < end) + *str = '%'; + ++str; + if (*fmt) { if (str < end) - *str = '%'; + *str = *fmt; ++str; - if (*fmt) { - if (str < end) - *str = *fmt; - ++str; - } else { - --fmt; - } - continue; + } else { + --fmt; + } + break; + + case FORMAT_TYPE_NRCHARS: { + int qualifier = spec.qualifier; + + if (qualifier == 'l') { + long *ip = va_arg(args, long *); + *ip = (str - buf); + } else if (qualifier == 'Z' || + qualifier == 'z') { + size_t *ip = va_arg(args, size_t *); + *ip = (str - buf); + } else { + int *ip = va_arg(args, int *); + *ip = (str - buf); + } + break; } - if (qualifier == 'L') - num = va_arg(args, long long); - else if (qualifier == 'l') { - num = va_arg(args, unsigned long); - if (flags & SIGN) - num = (signed long) num; - } else if (qualifier == 'Z' || qualifier == 'z') { - num = va_arg(args, size_t); - } else if (qualifier == 't') { - num = va_arg(args, ptrdiff_t); - } else if (qualifier == 'h') { - num = (unsigned short) va_arg(args, int); - if (flags & SIGN) - num = (signed short) num; - } else { - num = va_arg(args, unsigned int); - if (flags & SIGN) - num = (signed int) num; + + default: + switch (spec.type) { + case FORMAT_TYPE_LONG_LONG: + num = va_arg(args, long long); + break; + case FORMAT_TYPE_ULONG: + num = va_arg(args, unsigned long); + break; + case FORMAT_TYPE_LONG: + num = va_arg(args, long); + break; + case FORMAT_TYPE_SIZE_T: + num = va_arg(args, size_t); + break; + case FORMAT_TYPE_PTRDIFF: + num = va_arg(args, ptrdiff_t); + break; + case FORMAT_TYPE_USHORT: + num = (unsigned short) va_arg(args, int); + break; + case FORMAT_TYPE_SHORT: + num = (short) va_arg(args, int); + break; + case FORMAT_TYPE_UINT: + num = va_arg(args, unsigned int); + break; + default: + num = va_arg(args, unsigned int); + } + + str = number(str, end, num, spec); } - str = number(str, end, num, base, - field_width, precision, flags); } + if (size > 0) { if (str < end) *str = '\0'; else end[-1] = '\0'; } + /* the trailing null byte doesn't count towards the total */ return str-buf; + } EXPORT_SYMBOL(vsnprintf); @@ -1084,8 +1270,9 @@ EXPORT_SYMBOL(sprintf); */ int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args) { + struct printf_spec spec = {0}; char *str, *end; - int qualifier; + int read; str = (char *)bin_buf; end = (char *)(bin_buf + size); @@ -1110,57 +1297,26 @@ do { \ str += sizeof(type); \ } while (0) - for (; *fmt ; ++fmt) { - if (*fmt != '%') - continue; -repeat: - /* parse flags */ - ++fmt; /* this also skips first '%' */ - if (*fmt == '-' || *fmt == '+' || *fmt == ' ' - || *fmt == '#' || *fmt == '0') - goto repeat; + while (*fmt) { + read = format_decode(fmt, &spec); - /* parse field width */ - if (isdigit(*fmt)) - skip_atoi(&fmt); - else if (*fmt == '*') { - ++fmt; - /* it's the next argument */ - save_arg(int); - } + fmt += read; - /* parse the precision */ - if (*fmt == '.') { - ++fmt; - if (isdigit(*fmt)) - skip_atoi(&fmt); - else if (*fmt == '*') { - ++fmt; - /* it's the next argument */ - save_arg(int); - } - } + switch (spec.type) { + case FORMAT_TYPE_NONE: + break; - /* parse the conversion qualifier */ - qualifier = -1; - if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' || - *fmt == 'Z' || *fmt == 'z' || *fmt == 't') { - qualifier = *fmt; - ++fmt; - if (qualifier == 'l' && *fmt == 'l') { - qualifier = 'L'; - ++fmt; - } - } + case FORMAT_TYPE_WITDH: + case FORMAT_TYPE_PRECISION: + save_arg(int); + break; - /* parse format type */ - switch (*fmt) { - case 'c': + case FORMAT_TYPE_CHAR: save_arg(char); - continue; - case 's': { - /* save the string argument */ + break; + + case FORMAT_TYPE_STR: { const char *save_str = va_arg(args, char *); size_t len; if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE @@ -1170,16 +1326,27 @@ repeat: if (str + len + 1 < end) memcpy(str, save_str, len + 1); str += len + 1; - continue; + break; } - case 'p': + + case FORMAT_TYPE_PTR: save_arg(void *); /* skip all alphanumeric pointer suffixes */ - while (isalnum(fmt[1])) + while (isalnum(*fmt)) fmt++; - continue; - case 'n': { + break; + + case FORMAT_TYPE_PERCENT_CHAR: + break; + + case FORMAT_TYPE_INVALID: + if (!*fmt) + --fmt; + break; + + case FORMAT_TYPE_NRCHARS: { /* skip %n 's argument */ + int qualifier = spec.qualifier; void *skip_arg; if (qualifier == 'l') skip_arg = va_arg(args, long *); @@ -1187,37 +1354,37 @@ repeat: skip_arg = va_arg(args, size_t *); else skip_arg = va_arg(args, int *); - continue; + break; } - case 'o': - case 'x': - case 'X': - case 'd': - case 'i': - case 'u': - /* save arg for case: 'o', 'x', 'X', 'd', 'i', 'u' */ - if (qualifier == 'L') + + default: + switch (spec.type) { + + case FORMAT_TYPE_LONG_LONG: save_arg(long long); - else if (qualifier == 'l') + break; + case FORMAT_TYPE_ULONG: + case FORMAT_TYPE_LONG: save_arg(unsigned long); - else if (qualifier == 'Z' || qualifier == 'z') + break; + case FORMAT_TYPE_SIZE_T: save_arg(size_t); - else if (qualifier == 't') + break; + case FORMAT_TYPE_PTRDIFF: save_arg(ptrdiff_t); - else if (qualifier == 'h') + break; + case FORMAT_TYPE_USHORT: + case FORMAT_TYPE_SHORT: save_arg(short); - else + break; + default: save_arg(int); - continue; - default: - if (!*fmt) - --fmt; - continue; + } } } -#undef save_arg - return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf; + +#undef save_arg } EXPORT_SYMBOL_GPL(vbin_printf); @@ -1249,14 +1416,10 @@ EXPORT_SYMBOL_GPL(vbin_printf); int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf) { unsigned long long num; - int base; char *str, *end, c; const char *args = (const char *)bin_buf; - int flags; - int field_width; - int precision; - int qualifier; + struct printf_spec spec = {0}; if (unlikely((int) size < 0)) { /* There can be only one.. */ @@ -1290,84 +1453,37 @@ int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf) size = end - buf; } - for (; *fmt ; ++fmt) { - if (*fmt != '%') { - if (str < end) - *str = *fmt; - ++str; - continue; - } + while (*fmt) { + int read; + const char *old_fmt = fmt; - /* process flags */ - flags = 0; -repeat: - ++fmt; /* this also skips first '%' */ - switch (*fmt) { - case '-': - flags |= LEFT; - goto repeat; - case '+': - flags |= PLUS; - goto repeat; - case ' ': - flags |= SPACE; - goto repeat; - case '#': - flags |= SPECIAL; - goto repeat; - case '0': - flags |= ZEROPAD; - goto repeat; - } + read = format_decode(fmt, &spec); - /* get field width */ - field_width = -1; - if (isdigit(*fmt)) - field_width = skip_atoi(&fmt); - else if (*fmt == '*') { - ++fmt; - /* it's the next argument */ - field_width = get_arg(int); - if (field_width < 0) { - field_width = -field_width; - flags |= LEFT; - } - } + fmt += read; - /* get the precision */ - precision = -1; - if (*fmt == '.') { - ++fmt; - if (isdigit(*fmt)) - precision = skip_atoi(&fmt); - else if (*fmt == '*') { - ++fmt; - /* it's the next argument */ - precision = get_arg(int); + switch (spec.type) { + case FORMAT_TYPE_NONE: { + int copy = read; + if (str < end) { + if (copy > end - str) + copy = end - str; + memcpy(str, old_fmt, copy); } - if (precision < 0) - precision = 0; + str += read; + break; } - /* get the conversion qualifier */ - qualifier = -1; - if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' || - *fmt == 'Z' || *fmt == 'z' || *fmt == 't') { - qualifier = *fmt; - ++fmt; - if (qualifier == 'l' && *fmt == 'l') { - qualifier = 'L'; - ++fmt; - } - } + case FORMAT_TYPE_WITDH: + spec.field_width = get_arg(int); + break; - /* default base */ - base = 10; + case FORMAT_TYPE_PRECISION: + spec.precision = get_arg(int); + break; - switch (*fmt) { - case 'c': - if (!(flags & LEFT)) { - while (--field_width > 0) { + case FORMAT_TYPE_CHAR: + if (!(spec.flags & LEFT)) { + while (--spec.field_width > 0) { if (str < end) *str = ' '; ++str; @@ -1377,58 +1493,34 @@ repeat: if (str < end) *str = c; ++str; - while (--field_width > 0) { + while (--spec.field_width > 0) { if (str < end) *str = ' '; ++str; } - continue; + break; - case 's':{ + case FORMAT_TYPE_STR: { const char *str_arg = args; size_t len = strlen(str_arg); args += len + 1; - str = string(str, end, (char *)str_arg, field_width, - precision, flags); - continue; + str = string(str, end, (char *)str_arg, spec); + break; } - case 'p': - str = pointer(fmt+1, str, end, get_arg(void *), - field_width, precision, flags); - /* Skip all alphanumeric pointer suffixes */ - while (isalnum(fmt[1])) + case FORMAT_TYPE_PTR: + str = pointer(fmt+1, str, end, get_arg(void *), spec); + while (isalnum(*fmt)) fmt++; - continue; - - case 'n': - /* skip %n */ - continue; + break; - case '%': + case FORMAT_TYPE_PERCENT_CHAR: if (str < end) *str = '%'; ++str; - continue; - - /* integer number formats - set up the flags and "break" */ - case 'o': - base = 8; - break; - - case 'x': - flags |= SMALL; - case 'X': - base = 16; break; - case 'd': - case 'i': - flags |= SIGN; - case 'u': - break; - - default: + case FORMAT_TYPE_INVALID: if (str < end) *str = '%'; ++str; @@ -1439,36 +1531,54 @@ repeat: } else { --fmt; } - continue; - } - if (qualifier == 'L') - num = get_arg(long long); - else if (qualifier == 'l') { - num = get_arg(unsigned long); - if (flags & SIGN) - num = (signed long) num; - } else if (qualifier == 'Z' || qualifier == 'z') { - num = get_arg(size_t); - } else if (qualifier == 't') { - num = get_arg(ptrdiff_t); - } else if (qualifier == 'h') { - num = (unsigned short) get_arg(short); - if (flags & SIGN) - num = (signed short) num; - } else { - num = get_arg(unsigned int); - if (flags & SIGN) - num = (signed int) num; + break; + + case FORMAT_TYPE_NRCHARS: + /* skip */ + break; + + default: + switch (spec.type) { + + case FORMAT_TYPE_LONG_LONG: + num = get_arg(long long); + break; + case FORMAT_TYPE_ULONG: + num = get_arg(unsigned long); + break; + case FORMAT_TYPE_LONG: + num = get_arg(unsigned long); + break; + case FORMAT_TYPE_SIZE_T: + num = get_arg(size_t); + break; + case FORMAT_TYPE_PTRDIFF: + num = get_arg(ptrdiff_t); + break; + case FORMAT_TYPE_USHORT: + num = get_arg(unsigned short); + break; + case FORMAT_TYPE_SHORT: + num = get_arg(short); + break; + case FORMAT_TYPE_UINT: + num = get_arg(unsigned int); + break; + default: + num = get_arg(int); + } + + str = number(str, end, num, spec); } - str = number(str, end, num, base, - field_width, precision, flags); } + if (size > 0) { if (str < end) *str = '\0'; else end[-1] = '\0'; } + #undef get_arg /* the trailing null byte doesn't count towards the total */ -- cgit v1.2.3