automake-1.16: SUBDIRS vs DIST_SUBDIRS
7.2.1 ‘SUBDIRS’ vs. ‘DIST_SUBDIRS’
----------------------------------
Automake considers two sets of directories, defined by the variables
‘SUBDIRS’ and ‘DIST_SUBDIRS’.
‘SUBDIRS’ contains the subdirectories of the current directory that
must be built (⇒Subdirectories). It must be defined manually;
Automake will never guess a directory is to be built. As we will see in
the next two sections, it is possible to define it conditionally so that
some directory will be omitted from the build.
‘DIST_SUBDIRS’ is used in rules that need to recurse in all
directories, even those that have been conditionally left out of the
build. Recall our example where we may not want to build subdirectory
‘opt/’, but yet we want to distribute it? This is where ‘DIST_SUBDIRS’
comes into play: ‘opt’ may not appear in ‘SUBDIRS’, but it must appear
in ‘DIST_SUBDIRS’.
Precisely, ‘DIST_SUBDIRS’ is used by ‘make maintainer-clean’, ‘make
distclean’ and ‘make dist’. All other recursive rules use ‘SUBDIRS’.
If ‘SUBDIRS’ is defined conditionally using Automake conditionals,
Automake will define ‘DIST_SUBDIRS’ automatically from the possible
values of ‘SUBDIRS’ in all conditions.
If ‘SUBDIRS’ contains ‘AC_SUBST’ variables, ‘DIST_SUBDIRS’ will not
be defined correctly because Automake does not know the possible values
of these variables. In this case ‘DIST_SUBDIRS’ needs to be defined
manually.
Info Catalog
automake-1.16: Conditional Subdirectories
automake-1.16: Subdirectories with AM_CONDITIONAL