1 # $NetBSD: varmod-order-shuffle.mk,v 1.5 2020/10/24 08:46:08 rillig Exp $
3 # Tests for the :Ox variable modifier, which returns the words of the
6 # As of 2020-08-16, make uses random(3) seeded by the current time in seconds.
7 # This makes the random numbers completely predictable since there is no other
8 # part of make that uses random numbers.
12 NUMBERS= one two three four five six seven eight nine ten
14 # Note that 1 in every 10! trials two independently generated
15 # randomized orderings will be the same. The test framework doesn't
16 # support checking probabilistic output, so we accept that each of the
17 # 3 :Ox tests will incorrectly fail with probability 2.756E-7, which
18 # lets the whole test fail once in 1.209.600 runs, on average.
20 # Create two shuffles using the := assignment operator.
21 shuffled1:= ${NUMBERS:Ox}
22 shuffled2:= ${NUMBERS:Ox}
23 .if ${shuffled1} == ${shuffled2}
24 . error ${shuffled1} == ${shuffled2}
27 # Sorting the list before shuffling it has no effect.
28 shuffled1:= ${NUMBERS:O:Ox}
29 shuffled2:= ${NUMBERS:O:Ox}
30 .if ${shuffled1} == ${shuffled2}
31 . error ${shuffled1} == ${shuffled2}
34 # Sorting after shuffling must produce the original numbers.
35 sorted:= ${NUMBERS:Ox:O}
36 .if ${sorted} != ${NUMBERS:O}
37 . error ${sorted} != ${NUMBERS:O}