Clever Geek Handbook

Creating targets from computed variables in make

Here's an example that doesn't work

say-hello := greeting
say-bye := farewell

greeting:
    @echo "Hello"

farewell:
    @echo "Bye"

.SECONDEXPANSION:
%-guvnah: $$(say-$*)
    @echo "Target was: $(say-$*)"

Command

make hello-guvnah

Should issue

hello
Target was: greeting

But only shows

Target was: greeting
+3


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1 answer


And this happens if you double-escape $*

the pre-order so that it expands during secondary expansion instead of the first pass:



.SECONDEXPANSION:
%-guvnah: $$(say-$$*)
    @echo "Target was: $(say-$*)"
+2


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