1*548bfc56SSimon J. Gerraty# $NetBSD: cond-cmp-string.mk,v 1.19 2024/04/23 22:51:28 rillig Exp $ 22c3632d1SSimon J. Gerraty# 32c3632d1SSimon J. Gerraty# Tests for string comparisons in .if conditions. 42c3632d1SSimon J. Gerraty 52c3632d1SSimon J. Gerraty# This is a simple comparison of string literals. 62c3632d1SSimon J. Gerraty# Nothing surprising here. 72c3632d1SSimon J. Gerraty.if "str" != "str" 82c3632d1SSimon J. Gerraty. error 92c3632d1SSimon J. Gerraty.endif 102c3632d1SSimon J. Gerraty 112c3632d1SSimon J. Gerraty# The right-hand side of the comparison may be written without quotes. 122c3632d1SSimon J. Gerraty.if "str" != str 132c3632d1SSimon J. Gerraty. error 142c3632d1SSimon J. Gerraty.endif 152c3632d1SSimon J. Gerraty 162c3632d1SSimon J. Gerraty# The left-hand side of the comparison must be enclosed in quotes. 172c3632d1SSimon J. Gerraty# This one is not enclosed in quotes and thus generates an error message. 188c973ee2SSimon J. Gerraty# expect+1: Malformed conditional (str != str) 192c3632d1SSimon J. Gerraty.if str != str 202c3632d1SSimon J. Gerraty. error 212c3632d1SSimon J. Gerraty.endif 222c3632d1SSimon J. Gerraty 23*548bfc56SSimon J. Gerraty# An expression that occurs on the left-hand side of the comparison must be 24*548bfc56SSimon J. Gerraty# defined. 25e2eeea75SSimon J. Gerraty# 26e2eeea75SSimon J. Gerraty# The variable named "" is never defined, nevertheless it can be used as a 27*548bfc56SSimon J. Gerraty# starting point for an expression. Applying the :U modifier to such an 28*548bfc56SSimon J. Gerraty# undefined expression turns it into a defined expression. 29e2eeea75SSimon J. Gerraty# 3012904384SSimon J. Gerraty# See ApplyModifier_Defined and DEF_DEFINED. 312c3632d1SSimon J. Gerraty.if ${:Ustr} != "str" 322c3632d1SSimon J. Gerraty. error 332c3632d1SSimon J. Gerraty.endif 342c3632d1SSimon J. Gerraty 352c3632d1SSimon J. Gerraty# Any character in a string literal may be escaped using a backslash. 362c3632d1SSimon J. Gerraty# This means that "\n" does not mean a newline but a simple "n". 372c3632d1SSimon J. Gerraty.if "string" != "\s\t\r\i\n\g" 382c3632d1SSimon J. Gerraty. error 392c3632d1SSimon J. Gerraty.endif 402c3632d1SSimon J. Gerraty 412c3632d1SSimon J. Gerraty# It is not possible to concatenate two string literals to form a single 42e2eeea75SSimon J. Gerraty# string. In C, Python and the shell this is possible, but not in make. 438c973ee2SSimon J. Gerraty# expect+1: Malformed conditional ("string" != "str""ing") 442c3632d1SSimon J. Gerraty.if "string" != "str""ing" 452c3632d1SSimon J. Gerraty. error 46e2eeea75SSimon J. Gerraty.else 47e2eeea75SSimon J. Gerraty. error 482c3632d1SSimon J. Gerraty.endif 49956e45f6SSimon J. Gerraty 50956e45f6SSimon J. Gerraty# There is no = operator for strings. 518c973ee2SSimon J. Gerraty# expect+1: Malformed conditional (!("value" = "value")) 52956e45f6SSimon J. Gerraty.if !("value" = "value") 53956e45f6SSimon J. Gerraty. error 54956e45f6SSimon J. Gerraty.else 55956e45f6SSimon J. Gerraty. error 56956e45f6SSimon J. Gerraty.endif 57956e45f6SSimon J. Gerraty 58956e45f6SSimon J. Gerraty# There is no === operator for strings either. 598c973ee2SSimon J. Gerraty# expect+1: Malformed conditional (!("value" === "value")) 60956e45f6SSimon J. Gerraty.if !("value" === "value") 61956e45f6SSimon J. Gerraty. error 62956e45f6SSimon J. Gerraty.else 63956e45f6SSimon J. Gerraty. error 64956e45f6SSimon J. Gerraty.endif 65956e45f6SSimon J. Gerraty 66d5e0a182SSimon J. Gerraty# An expression can be enclosed in double quotes. 67956e45f6SSimon J. Gerraty.if ${:Uword} != "${:Uword}" 68956e45f6SSimon J. Gerraty. error 69956e45f6SSimon J. Gerraty.endif 70956e45f6SSimon J. Gerraty 71956e45f6SSimon J. Gerraty# Between 2003-01-01 (maybe even earlier) and 2020-10-30, adding one of the 72*548bfc56SSimon J. Gerraty# characters " \t!=><" directly after an expression in a string literal 73*548bfc56SSimon J. Gerraty# resulted in a "Malformed conditional", even though the string was 74*548bfc56SSimon J. Gerraty# well-formed. 75956e45f6SSimon J. Gerraty.if ${:Uword } != "${:Uword} " 76956e45f6SSimon J. Gerraty. error 77956e45f6SSimon J. Gerraty.endif 78956e45f6SSimon J. Gerraty# Some other characters worked though, and some didn't. 79956e45f6SSimon J. Gerraty# Those that are mentioned in is_separator didn't work. 80956e45f6SSimon J. Gerraty.if ${:Uword0} != "${:Uword}0" 81956e45f6SSimon J. Gerraty. error 82956e45f6SSimon J. Gerraty.endif 83956e45f6SSimon J. Gerraty.if ${:Uword&} != "${:Uword}&" 84956e45f6SSimon J. Gerraty. error 85956e45f6SSimon J. Gerraty.endif 86956e45f6SSimon J. Gerraty.if ${:Uword!} != "${:Uword}!" 87956e45f6SSimon J. Gerraty. error 88956e45f6SSimon J. Gerraty.endif 89956e45f6SSimon J. Gerraty.if ${:Uword<} != "${:Uword}<" 90956e45f6SSimon J. Gerraty. error 91956e45f6SSimon J. Gerraty.endif 92956e45f6SSimon J. Gerraty 93d5e0a182SSimon J. Gerraty# Adding another expression to the string literal works though. 94956e45f6SSimon J. Gerraty.if ${:Uword} != "${:Uwo}${:Urd}" 95956e45f6SSimon J. Gerraty. error 96956e45f6SSimon J. Gerraty.endif 97956e45f6SSimon J. Gerraty 98*548bfc56SSimon J. Gerraty# Adding a space at the beginning of the quoted expression works though. 99956e45f6SSimon J. Gerraty.if ${:U word } != " ${:Uword} " 100956e45f6SSimon J. Gerraty. error 101956e45f6SSimon J. Gerraty.endif 102e2eeea75SSimon J. Gerraty 103e2eeea75SSimon J. Gerraty# If at least one side of the comparison is a string literal, the string 104e2eeea75SSimon J. Gerraty# comparison is performed. 105e2eeea75SSimon J. Gerraty.if 12345 != "12345" 106e2eeea75SSimon J. Gerraty. error 107e2eeea75SSimon J. Gerraty.endif 108e2eeea75SSimon J. Gerraty 109e2eeea75SSimon J. Gerraty# If at least one side of the comparison is a string literal, the string 110e2eeea75SSimon J. Gerraty# comparison is performed. The ".0" in the left-hand side makes the two 111e2eeea75SSimon J. Gerraty# sides of the equation unequal. 112e2eeea75SSimon J. Gerraty.if 12345.0 == "12345" 113e2eeea75SSimon J. Gerraty. error 114e2eeea75SSimon J. Gerraty.endif 115dba7b0efSSimon J. Gerraty 116dba7b0efSSimon J. Gerraty# Strings cannot be compared relationally, only for equality. 1178c973ee2SSimon J. Gerraty# expect+1: Comparison with '<' requires both operands 'string' and 'string' to be numeric 118dba7b0efSSimon J. Gerraty.if "string" < "string" 119dba7b0efSSimon J. Gerraty. error 120dba7b0efSSimon J. Gerraty.else 121dba7b0efSSimon J. Gerraty. error 122dba7b0efSSimon J. Gerraty.endif 123dba7b0efSSimon J. Gerraty 124dba7b0efSSimon J. Gerraty# Strings cannot be compared relationally, only for equality. 1258c973ee2SSimon J. Gerraty# expect+1: Comparison with '<=' requires both operands 'string' and 'string' to be numeric 126dba7b0efSSimon J. Gerraty.if "string" <= "string" 127dba7b0efSSimon J. Gerraty. error 128dba7b0efSSimon J. Gerraty.else 129dba7b0efSSimon J. Gerraty. error 130dba7b0efSSimon J. Gerraty.endif 131dba7b0efSSimon J. Gerraty 132dba7b0efSSimon J. Gerraty# Strings cannot be compared relationally, only for equality. 1338c973ee2SSimon J. Gerraty# expect+1: Comparison with '>' requires both operands 'string' and 'string' to be numeric 134dba7b0efSSimon J. Gerraty.if "string" > "string" 135dba7b0efSSimon J. Gerraty. error 136dba7b0efSSimon J. Gerraty.else 137dba7b0efSSimon J. Gerraty. error 138dba7b0efSSimon J. Gerraty.endif 139dba7b0efSSimon J. Gerraty 140dba7b0efSSimon J. Gerraty# Strings cannot be compared relationally, only for equality. 1418c973ee2SSimon J. Gerraty# expect+1: Comparison with '>=' requires both operands 'string' and 'string' to be numeric 142dba7b0efSSimon J. Gerraty.if "string" >= "string" 143dba7b0efSSimon J. Gerraty. error 144dba7b0efSSimon J. Gerraty.else 145dba7b0efSSimon J. Gerraty. error 146dba7b0efSSimon J. Gerraty.endif 147954401e6SSimon J. Gerraty 148*548bfc56SSimon J. Gerraty# Two expressions with different values compare unequal. 149954401e6SSimon J. GerratyVAR1= value1 150954401e6SSimon J. GerratyVAR2= value2 151954401e6SSimon J. Gerraty.if ${VAR1} != ${VAR2} 152954401e6SSimon J. Gerraty.else 153954401e6SSimon J. Gerraty. error 154954401e6SSimon J. Gerraty.endif 155