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gilligan/Makefile

Created February 8, 2015 19:10
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parallel make problem
Raw
magic
#!/bin/bash
echo "MAGIC!"
cp src/foo.y dst/foo.x
cp src/bar.y dst/bar.x
cp src/baz.y dst/baz.x
Raw
Makefile
all: foo
foo: dst/foo.x dst/bar.x dst/baz.x
dst/foo.x dst/bar.x dst/baz.x : src/foo.y src/bar.y src/baz.y
@./magic
clean:
rm dst/*
@gilligan
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gilligan commented Feb 8, 2015 

$ make
MAGIC!

versus

$ make -j 8
MAGIC!
MAGIC!
MAGIC!
cp: cannot create regular file ‘dst/foo.x’: File exists

how can I get make to only invoke magic once as it is supposed to ?

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gilligan commented Feb 8, 2015 

all: foo
foo: dst/foo.x dst/bar.x dst/baz.x
dst/%.x: src/%.y ; ./magic
clean:
    -rm dst/*

#dst/foo.x dst/bar.x dst/baz.x : src/foo.y src/bar.y src/baz.y

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