diff options
Diffstat (limited to 'src/editfns.c')
| -rw-r--r-- | src/editfns.c | 43 |
1 files changed, 31 insertions, 12 deletions
diff --git a/src/editfns.c b/src/editfns.c index 98187df5d97..1dbae8f5d4b 100644 --- a/src/editfns.c +++ b/src/editfns.c @@ -3851,6 +3851,23 @@ usage: (propertize STRING &rest PROPERTIES) */) return string; } +/* Convert the prefix of STR from ASCII decimal digits to a number. + Set *STR_END to the address of the first non-digit. Return the + number, or PTRDIFF_MAX on overflow. Return 0 if there is no number. + This is like strtol for ptrdiff_t and base 10 and C locale, + except without negative numbers or errno. */ + +static ptrdiff_t +str2num (char *str, char **str_end) +{ + ptrdiff_t n = 0; + for (; c_isdigit (*str); str++) + if (INT_MULTIPLY_WRAPV (n, 10, &n) || INT_ADD_WRAPV (n, *str - '0', &n)) + n = PTRDIFF_MAX; + *str_end = str; + return n; +} + DEFUN ("format", Fformat, Sformat, 1, MANY, 0, doc: /* Format a string out of a format-string and arguments. The first argument is a format control string. @@ -4057,17 +4074,16 @@ styled_format (ptrdiff_t nargs, Lisp_Object *args, bool message) digits to print after the '.' for floats, or the max. number of chars to print from a string. */ - uintmax_t num; + ptrdiff_t num; char *num_end; if (c_isdigit (*format)) { - num = strtoumax (format, &num_end, 10); + num = str2num (format, &num_end); if (*num_end == '$') { if (num == 0) error ("Invalid format field number 0"); - n = min (num, PTRDIFF_MAX); - n--; + n = num - 1; format = num_end + 1; } } @@ -4095,15 +4111,15 @@ styled_format (ptrdiff_t nargs, Lisp_Object *args, bool message) space_flag &= ! plus_flag; zero_flag &= ! minus_flag; - num = strtoumax (format, &num_end, 10); + num = str2num (format, &num_end); if (max_bufsize <= num) string_overflow (); ptrdiff_t field_width = num; bool precision_given = *num_end == '.'; - uintmax_t precision = (precision_given - ? strtoumax (num_end + 1, &num_end, 10) - : UINTMAX_MAX); + ptrdiff_t precision = (precision_given + ? str2num (num_end + 1, &num_end) + : PTRDIFF_MAX); format = num_end; if (format == end) @@ -4176,7 +4192,7 @@ styled_format (ptrdiff_t nargs, Lisp_Object *args, bool message) /* handle case (precision[n] >= 0) */ ptrdiff_t prec = -1; - if (precision_given && precision <= TYPE_MAXIMUM (ptrdiff_t)) + if (precision_given) prec = precision; /* lisp_string_width ignores a precision of 0, but GNU @@ -4424,8 +4440,9 @@ styled_format (ptrdiff_t nargs, Lisp_Object *args, bool message) padding and excess precision. Deal with excess precision first. This happens only when the format specifies ridiculously large precision. */ - uintmax_t excess_precision = precision - prec; - uintmax_t leading_zeros = 0, trailing_zeros = 0; + ptrdiff_t excess_precision + = precision_given ? precision - prec : 0; + ptrdiff_t leading_zeros = 0, trailing_zeros = 0; if (excess_precision) { if (float_conversion) @@ -4451,7 +4468,9 @@ styled_format (ptrdiff_t nargs, Lisp_Object *args, bool message) /* Compute the total bytes needed for this item, including excess precision and padding. */ - uintmax_t numwidth = sprintf_bytes + excess_precision; + ptrdiff_t numwidth; + if (INT_ADD_WRAPV (sprintf_bytes, excess_precision, &numwidth)) + numwidth = PTRDIFF_MAX; ptrdiff_t padding = numwidth < field_width ? field_width - numwidth : 0; if (max_bufsize - sprintf_bytes <= excess_precision |