Home | History | Annotate | Line # | Download | only in unit-tests 
      1 # $NetBSD: varmod-undefined.mk,v 1.11 2024/06/03 02:46:29 sjg Exp $
      2 #
      3 # Tests for the :U variable modifier, which returns the given string
      4 # if the variable is undefined.
      5 #
      6 # See also:
      7 #	directive-for.mk
      8 #	varmod-defined.mk
      9 
     10 # this test depends on
     11 .MAKE.SAVE_DOLLARS= yes
     12 
     13 # The pattern ${:Uword} is heavily used when expanding .for loops.
     14 #
     15 # This is how an expanded .for loop looks like.
     16 # .for word in one
     17 # .  if ${word} != one
     18 .if ${:Uone} != one
     19 # .    error ${word}
     20 .  error ${:Uone}
     21 # .  endif
     22 .endif
     23 # .endfor
     24 
     25 # The expressions in the text of the :U modifier may be arbitrarily
     26 # nested.
     27 
     28 .if ${:U${:Unested}${${${:Udeeply}}}} != nested
     29 .  error
     30 .endif
     31 
     32 # The nested expressions may contain braces, and these braces don't
     33 # need to match pairwise.  In the following example, the :S modifier uses '{'
     34 # as delimiter, which confuses both editors and humans because the opening
     35 # and closing braces don't match anymore.  It's syntactically valid though.
     36 # For more similar examples, see varmod-subst.mk, mod-subst-delimiter.
     37 
     38 .if ${:U${:Uvalue:S{a{X{}} != vXlue
     39 .  error
     40 .endif
     41 
     42 # The escaping rules for the :U modifier (left-hand side) and condition
     43 # string literals (right-hand side) are completely different.
     44 #
     45 # In the :U modifier, the backslash only escapes very few characters, all
     46 # other backslashes are retained.
     47 #
     48 # In condition string literals, the backslash always escapes the following
     49 # character, no matter whether it would be necessary or not.
     50 #
     51 # In both contexts, \n is an escaped letter n, not a newline; that's what
     52 # the .newline variable is for.
     53 #
     54 # Whitespace at the edges is preserved, on both sides of the comparison.
     55 #
     56 .if ${:U \: \} \$ \\ \a \b \n } != " : } \$ \\ \\a \\b \\n "
     57 .  error
     58 .endif
     59 # An expression enclosed in quotes may be based on an undefined variable.
     60 .if "${:U \: \} \$ \\ \a \b \n }" != " : } \$ \\ \\a \\b \\n "
     61 .  error
     62 .endif
     63 
     64 # Even after the :U modifier has been applied, the expression still remembers
     65 # that it originated from an undefined variable, and the :U modifier can
     66 # be used to overwrite the value of the expression.
     67 #
     68 .if ${UNDEF:Uvalue:S,a,X,} != "vXlue"
     69 .  error
     70 .elif ${UNDEF:Uvalue:S,a,X,:Uwas undefined} != "was undefined"
     71 .  error
     72 .endif
     73 
     74 
     75 # VARE_PARSE
     76 .if 0 && ${:U . \: \} \$ \\ ${EXPR}}
     77 .  error
     78 .endif
     79 
     80 # VARE_EVAL_KEEP_DOLLAR_AND_UNDEFINED
     81 SUBST:=		${:U . \: \} \$ \\ ${EXPR}}
     82 ${:U }=		<space>
     83 EXPR=		<expr>
     84 .if ${SUBST} != " . : } <space>\\ "
     85 .  error
     86 .endif
     87 
     88 8_DOLLAR=	$$$$$$$$
     89 .if ${8_DOLLAR} != "\$\$\$\$"
     90 .  error
     91 .endif
     92 .if ${:U${8_DOLLAR}} != "\$\$\$\$"
     93 .  error
     94 .endif
     95 .if ${x:L:@_@${8_DOLLAR}@} != "\$\$\$\$"
     96 .  error
     97 .endif
     98 EXPR:=		${8_DOLLAR}
     99 .if ${EXPR} != "\$\$\$\$"
    100 .  error
    101 .endif
    102 EXPR:=		${:U${8_DOLLAR}}
    103 .if ${EXPR} != "\$\$\$\$"
    104 .  error
    105 .endif
    106 # VARE_EVAL_KEEP_UNDEFINED
    107 EXPR:=		${x:L:@_@${8_DOLLAR}@}
    108 .if ${EXPR} != "\$\$"
    109 .  error
    110 .endif
    111 
    112 
    113 all: .PHONY
    114