| 1 | #include "../git-compat-util.h" |
| 2 | |
| 3 | /* |
| 4 | * The size parameter specifies the available space, i.e. includes |
| 5 | * the trailing NUL byte; but Windows's vsnprintf uses the entire |
| 6 | * buffer and avoids the trailing NUL, should the buffer be exactly |
| 7 | * big enough for the result. Defining SNPRINTF_SIZE_CORR to 1 will |
| 8 | * therefore remove 1 byte from the reported buffer size, so we |
| 9 | * always have room for a trailing NUL byte. |
| 10 | */ |
| 11 | #ifndef SNPRINTF_SIZE_CORR |
| 12 | #if defined(WIN32) && (!defined(__GNUC__) || __GNUC__ < 4) && (!defined(_MSC_VER) || _MSC_VER < 1900) |
| 13 | #define SNPRINTF_SIZE_CORR 1 |
| 14 | #else |
| 15 | #define SNPRINTF_SIZE_CORR 0 |
| 16 | #endif |
| 17 | #endif |
| 18 | |
| 19 | #undef vsnprintf |
| 20 | int git_vsnprintf(char *str, size_t maxsize, const char *format, va_list ap) |
| 21 | { |
| 22 | va_list cp; |
| 23 | char *s; |
| 24 | int ret = -1; |
| 25 | |
| 26 | if (maxsize > 0) { |
| 27 | va_copy(cp, ap); |
| 28 | ret = vsnprintf(str, maxsize-SNPRINTF_SIZE_CORR, format, cp); |
| 29 | va_end(cp); |
| 30 | if (ret == maxsize-1) |
| 31 | ret = -1; |
| 32 | /* Windows does not NUL-terminate if result fills buffer */ |
| 33 | str[maxsize-1] = 0; |
| 34 | } |
| 35 | if (ret != -1) |
| 36 | return ret; |
| 37 | |
| 38 | s = NULL; |
| 39 | if (maxsize < 128) |
| 40 | maxsize = 128; |
| 41 | |
| 42 | while (ret == -1) { |
| 43 | maxsize *= 4; |
| 44 | str = realloc(s, maxsize); |
| 45 | if (! str) |
| 46 | break; |
| 47 | s = str; |
| 48 | va_copy(cp, ap); |
| 49 | ret = vsnprintf(str, maxsize-SNPRINTF_SIZE_CORR, format, cp); |
| 50 | va_end(cp); |
| 51 | if (ret == maxsize-1) |
| 52 | ret = -1; |
| 53 | } |
| 54 | free(s); |
| 55 | return ret; |
| 56 | } |
| 57 | |
| 58 | int git_snprintf(char *str, size_t maxsize, const char *format, ...) |
| 59 | { |
| 60 | va_list ap; |
| 61 | int ret; |
| 62 | |
| 63 | va_start(ap, format); |
| 64 | ret = git_vsnprintf(str, maxsize, format, ap); |
| 65 | va_end(ap); |
| 66 | |
| 67 | return ret; |
| 68 | } |
| 69 |