Integers can be hexadecimal, decimal or octal. An optional case-insensitive
suffix specifies their size: HH: 8 bit, H/S: 16 bit, L: 32 bit, LL: 64 bit
An optional U suffix makes a number unsigned. Ordinary 0x hex numbers are
always treated as unsigned. +0x or -0x hex numbers are treated as signed
unless they have a U suffix. Unsigned integers cannot be larger than 2^64-1.
If n is an unsigned integer then -n is also a valid unsigned integer as in C.
Signed integers must fall into the [-2^63, 2^63-1] range or a correspondingly
smaller range when a suffix specifies a smaller type. Out of range signed
numbers trigger a warning.
Ordinary 0x hex numbers with n hex digits (counting leading zeros) use
the smallest size of 1, 2, 4 and 8 bytes that can accommodate any n-digit hex
number. If a suffix specifies a size explicitly the corresponding number of
least significant bytes are written. Otherwise, signed and unsigned integers
alike occupy the smallest of 1, 2, 4, or 8 bytes needed to accommodate them
in their respective representation.
Using strtoll() can only return numbers in the range [-2^63, 2^63-1]. This
means that 0xffffFFFFffffFFFF (2^64-1) will be out of range and is written as
max LL. Actually, every 64-bit number with high-bit set will wrongly be
written as max LL.
This commit uses strtoull() instead to fix this, and checks for unsiged out-
of-range error. strtoull() also has the neat benefit that input with a minus
sign is treated like C unsigned numbers, ie, -u is also a valid unsigned
number if only u is one. In case the input is meant to be treated as signed,
it is therefore still OK to use strtoull() in the first instance only that in
this case a second check against the range of the signed domain is necessary.
Stefan Rueger