Programming

Quick question about Makefiles: is there any reason to put recipe lines inside parens? I'm not asking about variable expansion -- I mean an entire line. For example, see SuiteSparse: https://github.com/DrTimothyAldenDavis/SuiteSparse/blob/dev/Makefile

Normally, you would use parens to make sure you don't mess with your state, but each line of a recipe in GNU Make is effectively run in its own environment anyway.

I've seen it a few places now, so just wondering whether it is simply stylistic preference or if there is some effect I'm missing.

EDIT: Okay, did find one case where it could matter, although it doesn't apply in SuiteSparse. If you use the .ONESHELL special target, then all lines of your recipes run in a single shell, rather than each getting their own shell. In that case, if you wanted to get back something like the original new-shell-per-line behavior, you could wrap lines in parens as described above. TIL.

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