[Scons-users] What are the $( ,,, $) for

[Russell, J.J.]

This one has got to be easy. This is about the syntax of _CPPINCFLAGS and other similar variables.  So

_CPPINCFLAGS = $( ${_concat(INCPREFIX, CPPPATH, INCSUFFIX, __env__, RDirs, TARGET, SOURCE)} $)

What is the purpose of leading $( and trailing $)’s.   They get emitted when the default definition of $CCCOMSTR is used, so they seemingly get passed to the compiler, but they really can’t since a cut and paste of the compile command results in GCC rejecting them as bad syntax.  (I find cutting and pasting the exact compile command useful when tracking down obscure errors.  I can just modify the command, but those syntactic elements are annoying.)

As a bonus question, what does the ‘$’ before the ‘{_concat do?  This must have to do with deferring the translation, but that’s kinda of vague.

Jim Russell