These blocks mostly consisted of redundant structure, following the same
#ifndef pattern over and over, with only minimal variation.
It's easier to maintain if the common structure is only written once and
encapsulated in a macro.
To avoid "defined but unused" warnings from GCC in the case where
MAKE_NATIVE is not defined, I had to add volatile. Adding
MAKE_ATTR_UNUSED alone would not preserve the rcsid variable in the
resulting binary.
The "at most" branch was never taken since all call sites in var.c only
ever need a substring, and the target buffer is not limited. Therefore
rename the function and make it simpler.
It's ok that bmake_strldup is defined as estrndup in case of USE_EMALLOC
since that function's implementation is compatible to the "copy
exactly", it just contains some extra null checks that will never match
since the variable values cannot (well, or should not) contain null
bytes. Theoretically they can, but the behavior then depends on the
exact implementation and is unreliable, therefore nobody does this.
After all, Makefiles are used for text processing, not for binary data.
Just in case the given str is not really a string.
The POSIX 2018 documentation on strndup does not specify as clearly as
possible whether s has to be a string or whether raw memory is
acceptable as well. It only indirectly calls the s parameter of strndup
a string.
with versions prefixed by MAKE_ATTR_* to avoid modifying the
implementation namespace. Make sure they are available in all places
using nonints.h to fix bootstrap on Linux.
