[src/trunk]: src/usr.bin/make/unit-tests tests/make: show how to use indirect...

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

details:   https://anonhg.NetBSD.org/src/rev/646f770ff155
branches:  trunk
changeset: 377214:646f770ff155
user:      rillig <rillig%NetBSD.org@localhost>
date:      Sat Jul 01 09:06:34 2023 +0000

description:
tests/make: show how to use indirect conditions in the '?:' modifier

diffstat:

 usr.bin/make/unit-tests/varmod-ifelse.exp |  26 ++++++++++----
 usr.bin/make/unit-tests/varmod-ifelse.mk  |  54 +++++++++++++++++++++++++-----
 2 files changed, 63 insertions(+), 17 deletions(-)

diffs (146 lines):

diff -r d85d78c82536 -r 646f770ff155 usr.bin/make/unit-tests/varmod-ifelse.exp
--- a/usr.bin/make/unit-tests/varmod-ifelse.exp Sat Jul 01 07:10:13 2023 +0000
+++ b/usr.bin/make/unit-tests/varmod-ifelse.exp Sat Jul 01 09:06:34 2023 +0000
@@ -16,17 +16,17 @@ CondParser_Eval: ${VAR} == value
 Comparing "value" == "value"
 Comparing "ok" != "ok"
 make: "varmod-ifelse.mk" line 158: no.
-make: "varmod-ifelse.mk" line 161: Comparison with '>=' requires both operands 'no' and '10' to be numeric
+make: "varmod-ifelse.mk" line 162: Comparison with '>=' requires both operands 'no' and '10' to be numeric
 make: Bad conditional expression 'string == "literal" || no >= 10' in 'string == "literal" || no >= 10?yes:no'
-make: "varmod-ifelse.mk" line 161: .
+make: "varmod-ifelse.mk" line 162: .
 make: Bad conditional expression 'string == "literal" &&  >= 10' in 'string == "literal" &&  >= 10?yes:no'
-make: "varmod-ifelse.mk" line 167: .
+make: "varmod-ifelse.mk" line 169: .
 make: Bad conditional expression 'string == "literal" ||  >= 10' in 'string == "literal" ||  >= 10?yes:no'
-make: "varmod-ifelse.mk" line 169: .
-make: "varmod-ifelse.mk" line 177: true
-make: "varmod-ifelse.mk" line 180: false
+make: "varmod-ifelse.mk" line 172: .
+make: "varmod-ifelse.mk" line 180: <true>
+make: "varmod-ifelse.mk" line 183: <false>
 make: Bad conditional expression '     ' in '  ?true:false'
-make: "varmod-ifelse.mk" line 182: 
+make: "varmod-ifelse.mk" line 186: <>
 CondParser_Eval: 0 && ${1:?${:Uthen0:S,}},,}:${:Uelse0:S,}},,}} != "not evaluated"
 CondParser_Eval: 1 && ${0:?${:Uthen1:S,}},,}:${:Uelse1:S,}},,}} != "else1"
 CondParser_Eval: 0
@@ -34,6 +34,18 @@ Comparing "else1" != "else1"
 CondParser_Eval: 2 && ${1:?${:Uthen2:S,}},,}:${:Uelse2:S,}},,}} != "then2"
 CondParser_Eval: 1
 Comparing "then2" != "then2"
+CondParser_Eval: ${DELAYED} == "one"
+Comparing "two" == "one"
+make: "varmod-ifelse.mk" line 282: no
+CondParser_Eval: ${DELAYED} == "two"
+Comparing "two" == "two"
+make: "varmod-ifelse.mk" line 284: yes
+CondParser_Eval: ${DELAYED} == "one"
+Comparing "two" == "one"
+make: "varmod-ifelse.mk" line 287: no
+CondParser_Eval: ${DELAYED} == "two"
+Comparing "two" == "two"
+make: "varmod-ifelse.mk" line 290: yes
 make: Fatal errors encountered -- cannot continue
 make: stopped in unit-tests
 exit status 1
diff -r d85d78c82536 -r 646f770ff155 usr.bin/make/unit-tests/varmod-ifelse.mk
--- a/usr.bin/make/unit-tests/varmod-ifelse.mk  Sat Jul 01 07:10:13 2023 +0000
+++ b/usr.bin/make/unit-tests/varmod-ifelse.mk  Sat Jul 01 09:06:34 2023 +0000
@@ -1,4 +1,4 @@
-# $NetBSD: varmod-ifelse.mk,v 1.22 2023/06/01 20:56:35 rillig Exp $
+# $NetBSD: varmod-ifelse.mk,v 1.23 2023/07/01 09:06:34 rillig Exp $
 #
 # Tests for the ${cond:?then:else} variable modifier, which evaluates either
 # the then-expression or the else-expression, depending on the condition.
@@ -97,11 +97,11 @@ COND:=      ${${UNDEF} == "":?bad-assign:bad-
 .endif
 .MAKEFLAGS: -d0
 
-# As of 2020-12-10, the variable "name" is first expanded, and the result of
+# As of 2020-12-10, the variable "VAR" is first expanded, and the result of
 # this expansion is then taken as the condition.  To force the variable
 # expression in the condition to be evaluated at exactly the right point,
 # the '$' of the intended '${VAR}' escapes from the parser in form of the
-# expression ${:U\$}.  Because of this escaping, the variable "name" and thus
+# expression ${:U\$}.  Because of this escaping, the variable "VAR" and thus
 # the condition ends up as "${VAR} == value", just as intended.
 #
 # This hack does not work for variables from .for loops since these are
@@ -156,15 +156,18 @@ STRING=           string
 NUMBER=                no              # not really a number
 # expect+1: no.
 .info ${${STRING} == "literal" && ${NUMBER} >= 10:?yes:no}.
-# expect+2: .
-# expect+1: Comparison with '>=' requires both operands 'no' and '10' to be numeric
+# expect+3: Comparison with '>=' requires both operands 'no' and '10' to be numeric
+# expect: make: Bad conditional expression 'string == "literal" || no >= 10' in 'string == "literal" || no >= 10?yes:no'
+# expect+1: .
 .info ${${STRING} == "literal" || ${NUMBER} >= 10:?yes:no}.
 
 # The following situation occasionally occurs with MKINET6 or similar
 # variables.
 NUMBER=                # empty, not really a number either
+# expect: make: Bad conditional expression 'string == "literal" &&  >= 10' in 'string == "literal" &&  >= 10?yes:no'
 # expect+1: .
 .info ${${STRING} == "literal" && ${NUMBER} >= 10:?yes:no}.
+# expect: make: Bad conditional expression 'string == "literal" ||  >= 10' in 'string == "literal" ||  >= 10?yes:no'
 # expect+1: .
 .info ${${STRING} == "literal" || ${NUMBER} >= 10:?yes:no}.
 
@@ -173,13 +176,14 @@ PLUS=             +
 ASTERISK=      *
 EMPTY=         # empty
 # "true" since "+" is not the empty string.
-# expect+1: true
-.info ${${PLUS}                :?true:false}
+# expect+1: <true>
+.info <${${PLUS}               :?true:false}>
 # "false" since the variable named "*" is not defined.
-# expect+1: false
-.info ${${ASTERISK}    :?true:false}
+# expect+1: <false>
+.info <${${ASTERISK}   :?true:false}>
 # syntax error since the condition is completely blank.
-.info ${${EMPTY}       :?true:false}
+# expect+1: <>
+.info <${${EMPTY}      :?true:false}>
 
 
 # Since the condition of the '?:' modifier is expanded before being parsed and
@@ -256,4 +260,34 @@ PRIMES=    2 3 5 7 11
 # with the 'then2' formed the result 'then2,,}}'.
 .  error
 .endif
+
+
+# Since the condition is taken from the variable name of the expression, not
+# from its value, it is evaluated early.  It is possible though to construct
+# conditions that are evaluated lazily, at exactly the right point.  There is
+# no way to escape a '$' directly in the variable name, but there are
+# alternative ways to bring a '$' into the condition.
+#
+#      In an indirect condition using the ':U' modifier, each '$', ':' and
+#      '}' must be escaped as '\$', '\:' and '\}', respectively, but '{' must
+#      not be escaped.
+#
+#      In an indirect condition using a separate variable, each '$' must be
+#      escaped as '$$'.
+#
+# These two forms allow the variables to contain arbitrary characters, as the
+# condition parser does not see them.
+DELAYED=       two
+# expect+1: no
+.info ${ ${:U \${DELAYED\} == "one"}:?yes:no}
+# expect+1: yes
+.info ${ ${:U \${DELAYED\} == "two"}:?yes:no}
+INDIRECT_COND1=        $${DELAYED} == "one"
+# expect+1: no
+.info ${ ${INDIRECT_COND1}:?yes:no}
+INDIRECT_COND2=        $${DELAYED} == "two"
+# expect+1: yes
+.info ${ ${INDIRECT_COND2}:?yes:no}
+
+
 .MAKEFLAGS: -d0