I did this by adding intelligence into the algorithm such that the
second expansion was only actually performed when the prerequisite list
contained at least one "$", so we knew it is actually needed.
Without this we were using up a LOT more memory, since every single
target (even ones never used by make) had their file variables
initialized. This also used a lot more CPU, since we needed to create
and populate a new variable hash table for every target.
There is one issue remaining with this feature: it leaks memory. In
pattern_search() we now initialize the file variables for every pattern
target, which allocates a hash table, etc. However, sometimes we
recursively invoke pattern_search() (for intermediate files) with an
automatic variable (alloca() I believe) as the file. When that function
returns, obviously, the file variable hash memory is lost.
Incorporate "order-only" prerequisites patch. Wrote a test for it.
The test shows what might be a bug in the code; I need to look at it
more closely (anyway it doesn't behave as I expected). Also I haven't
done the docs yet.
New version of the manual, put into the doc subdir.
Enhancements: $(eval ...) and $(value ...) functions, various bug
fixes, etc. See the ChangeLog.
More to come.
* Update maintainers build process; remove GNUmakefile. Require builders to
run automake && autoreconf by hand.
* Use AC_SUBST_FILE to get the maintMakefile included, rather than GNU
make's include directive, which conflicts with automake 1.4's include
directive.