This extends our ifdef/ifndef test attributes to support more
complicated logic expressions.
So far we haven't really needed this (ifdef/ifndef accepts an implicitly
anded list, which has covered everything so far), but I realized there's
a simple trick to make this work.
For example, in test.toml:
ifdef = 'A && !(B || C)'
Generated ifdef:
#if (defined(A) && !(defined(B) || defined(C)))
This doesn't require complex parsing or anything, just a simple regex:
s/[a-zA-Z_0-9]\+/defined(&)/g
Is using #if defined(A) everywhere instead of #ifdef A more expensive
for the compiler? Not sure. But it seems like we're heavily dominated by
the single-threaded link time, so I'm not sure we care.
Christopher Haster
0c6e455961