[src/trunk]: src/usr.bin/make/unit-tests tests/make: remove dependency on exp...

[rillig <rillig%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/f2a3ff1a2afa
branches:  trunk
changeset: 373128:f2a3ff1a2afa
user:      rillig <rillig%NetBSD.org@localhost>
date:      Thu Jan 19 22:48:42 2023 +0000

description:
tests/make: remove dependency on expr(1) from a test

This saves 124 calls to the shell.

diffstat:

 usr.bin/make/unit-tests/hanoi-include.mk |  18 ++++++++++++------
 1 files changed, 12 insertions(+), 6 deletions(-)

diffs (43 lines):

diff -r a00be4d7ba9d -r f2a3ff1a2afa usr.bin/make/unit-tests/hanoi-include.mk
--- a/usr.bin/make/unit-tests/hanoi-include.mk  Thu Jan 19 21:33:06 2023 +0000
+++ b/usr.bin/make/unit-tests/hanoi-include.mk  Thu Jan 19 22:48:42 2023 +0000
@@ -1,4 +1,4 @@
-# $NetBSD: hanoi-include.mk,v 1.3 2022/05/08 07:27:50 rillig Exp $
+# $NetBSD: hanoi-include.mk,v 1.4 2023/01/19 22:48:42 rillig Exp $
 #
 # Implements the Towers of Hanoi puzzle, demonstrating a bunch of more or less
 # useful programming techniques:
@@ -21,22 +21,28 @@
 VIA?=  B                       # ... via this stack ...
 TO?=   C                       # ... to this stack.
 
-.if $N == 1
+# Since make has no built-in arithmetic functions, convert N to a list of
+# words and use the built-in word counting instead.
+.if ${N:[#]} == 1
+N:=    count ${:U:${:Urange=$N}}       # 'count' + one word for every disk
+.endif
+
+.if ${N:[#]} == 2
 .  for from to in ${FROM} ${TO}
 all::
        @echo "Move the upper disk from stack ${from} to stack ${to}."
 .  endfor
 .else
-_:=    ${N::!=expr $N - 1} ${TMP::=${VIA}} ${VIA::=${TO}} ${TO::=${TMP}}
+_:=    ${N::=${N:[1..-2]}} ${TMP::=${VIA}} ${VIA::=${TO}} ${TO::=${TMP}}
 .  include "${.PARSEDIR}/${.PARSEFILE}"
-_:=    ${N::!=expr $N + 1} ${TMP::=${VIA}} ${VIA::=${TO}} ${TO::=${TMP}}
+_:=    ${N::+=D} ${TMP::=${VIA}} ${VIA::=${TO}} ${TO::=${TMP}}
 
 .  for from to in ${FROM} ${TO}
 all::
        @echo "Move the upper disk from stack ${from} to stack ${to}."
 .  endfor
 
-_:=    ${N::!=expr $N - 1} ${TMP::=${VIA}} ${VIA::=${FROM}} ${FROM::=${TMP}}
+_:=    ${N::=${N:[1..-2]}} ${TMP::=${VIA}} ${VIA::=${FROM}} ${FROM::=${TMP}}
 .  include "${.PARSEDIR}/${.PARSEFILE}"
-_:=    ${N::!=expr $N + 1} ${TMP::=${VIA}} ${VIA::=${FROM}} ${FROM::=${TMP}}
+_:=    ${N::+=D} ${TMP::=${VIA}} ${VIA::=${FROM}} ${FROM::=${TMP}}
 .endif