style.Makefile: document the style for lists

[sjg]

share/man/man5/style.Makefile.5

262

probably worth calling out that a list of libs that represent link-order is a well known exception.

Also do you want to specify a trigger for the above format?
Ie a single line list of up to N elements is ok, but beyond that switch to one per line format.

[obrien]

share/man/man5/style.Makefile.5

262

Based on 0e1e341b486cdf it would seem not even libs need to be an exception. I have added a "trigger".

[obrien]

update

[obrien]

update

[jhb]

Eh, I'm not sure this is actually the style we want? Lots of places in the tree fix the diff problem by just using multiple += statements, e.g.:

FOO= foo
FOO+= bar
FOO+= baz

The solution advocated here is only in limited use in the tree and it might be better to recommend something already in use.

[sjg]

In D53429#1221417, @jhb wrote:

Eh, I'm not sure this is actually the style we want? Lots of places in the tree fix the diff problem by just using multiple += statements, e.g.:

FOO= foo
FOO+= bar
FOO+= baz

Good comment/question.
The += approach certainly works and can achieve the same goal.
There's cost though in terms of memory churn in make.

The solution advocated here is only in limited use in the tree and it might be better to recommend something already in use.

Readability and maintainability of makefiles is important and changing style for change sake is bad.

There seem to be enough people who care about build performance though to perhaps give some weight to makefile efficiency?

For small makefiles it makes little difference, but for large makefiles the difference is measurable.