diff options
Diffstat (limited to 'common/printf.c')
| -rw-r--r-- | common/printf.c | 236 |
1 files changed, 236 insertions, 0 deletions
diff --git a/common/printf.c b/common/printf.c new file mode 100644 index 0000000000..af393daa0b --- /dev/null +++ b/common/printf.c @@ -0,0 +1,236 @@ +/* Copyright (c) 2012 The Chromium OS Authors. All rights reserved. + * Use of this source code is governed by a BSD-style license that can be + * found in the LICENSE file. + */ + +/* Printf-like functionality for Chrome EC */ + +#include "printf.h" +#include "timer.h" +#include "util.h" + +static const char error_str[] = "ERROR"; + +int vfnprintf(int (*addchar)(void *context, int c), void *context, + const char *format, va_list args) +{ + char intbuf[34]; + /* Longest uint64 in decimal = 20 + * longest uint32 in binary = 32 + */ + int dropped_chars = 0; + int is_left; + int pad_zero; + int pad_width; + char *vstr; + int vlen; + + while (*format && !dropped_chars) { + int c = *format++; + + /* Copy normal characters */ + if (c != '%') { + dropped_chars |= addchar(context, c); + continue; + } + + /* Get first format character */ + c = *format++; + + /* Send "%" for "%%" input */ + if (c == '%' || c == '\0') { + dropped_chars |= addchar(context, '%'); + continue; + } + + /* Handle %c */ + if (c == 'c') { + c = va_arg(args, int); + dropped_chars |= addchar(context, c); + continue; + } + + /* Handle left-justification ("%-5s") */ + is_left = (c == '-'); + if (is_left) + c = *format++; + + /* Handle padding with 0's */ + pad_zero = (c == '0'); + if (pad_zero) + c = *format++; + + /* Count padding length */ + pad_width = 0; + while (c >= '0' && c <= '9') { + pad_width = (10 * pad_width) + c - '0'; + c = *format++; + } + if (pad_width > 80) { + /* Sanity check for width failed */ + format = error_str; + continue; + } + + if (c == 's') { + vstr = va_arg(args, char *); + if (vstr == NULL) + vstr = "(NULL)"; + } else { + uint64_t v; + int is_negative = 0; + int is_64bit = 0; + int base = 10; + int fixed_point = 0; + + /* Handle fixed point numbers */ + if (c == '.') { + c = *format++; + if (c < '0' || c > '9') { + format = error_str; + continue; + } + fixed_point = c - '0'; + c = *format++; + } + + if (c == 'l') { + is_64bit = 1; + c = *format++; + } + + /* Special-case: %T = current time */ + if (c == 'T') { + v = get_time().val; + is_64bit = 1; + fixed_point = 6; + } else if (is_64bit) { + v = va_arg(args, uint64_t); + } else { + v = va_arg(args, uint32_t); + } + + switch (c) { + case 'd': + if (is_64bit) { + if ((int64_t)v < 0) { + is_negative = 1; + if (v != (1ULL << 63)) + v = -v; + } + } else { + if ((int)v < 0) { + is_negative = 1; + if (v != (1ULL << 31)) + v = -(int)v; + } + } + break; + case 'u': + case 'T': + break; + case 'X': + case 'x': + case 'p': + base = 16; + break; + case 'b': + base = 2; + break; + default: + format = error_str; + } + if (format == error_str) + continue; /* Bad format specifier */ + + /* Convert integer to string, starting at end of + * buffer and working backwards. */ + vstr = intbuf + sizeof(intbuf) - 1; + *(vstr) = '\0'; + + /* Handle digits to right of decimal for fixed point + * numbers. */ + for (vlen = 0; vlen < fixed_point; vlen++) + *(--vstr) = '0' + uint64divmod(&v, 10); + if (fixed_point) + *(--vstr) = '.'; + + if (!v) + *(--vstr) = '0'; + + while (v) { + int digit = uint64divmod(&v, base); + if (digit < 10) + *(--vstr) = '0' + digit; + else if (c == 'X') + *(--vstr) = 'A' + digit - 9; + else + *(--vstr) = 'a' + digit - 9; + } + + if (is_negative) + *(--vstr) = '-'; + } + + /* Copy string (or stringified integer) */ + vlen = strlen(vstr); + while (vlen < pad_width && !is_left) { + dropped_chars |= addchar(context, pad_zero ? '0' : ' '); + vlen++; + } + while (*vstr) + dropped_chars |= addchar(context, *vstr++); + while (vlen < pad_width && is_left) { + dropped_chars |= addchar(context, ' '); + vlen++; + } + } + + /* Successful if we consumed all output */ + return dropped_chars ? EC_ERROR_OVERFLOW : EC_SUCCESS; +} + + +/* Context for snprintf() */ +struct snprintf_context { + char *str; + int size; +}; + + +/* Add a character to the string */ +static int snprintf_addchar(void *context, int c) +{ + struct snprintf_context *ctx = (struct snprintf_context *)context; + + if (!ctx->size) + return 1; + + *(ctx->str++) = c; + ctx->size--; + return 0; +} + + +/* Print formatted outut to a string */ +int snprintf(char *str, int size, const char *format, ...) +{ + struct snprintf_context ctx; + va_list args; + int rv; + + if (!str || !size) + return EC_ERROR_INVAL; + + ctx.str = str; + ctx.size = size - 1; /* Reserve space for terminating '\0' */ + + va_start(args, format); + rv = vfnprintf(snprintf_addchar, &ctx, format, args); + va_end(args); + + /* Terminate string */ + *ctx.str = '\0'; + + return rv; +} |