1 1.7 rillig # $NetBSD: varname-dot-make-save_dollars.mk,v 1.7 2021/12/03 18:43:52 rillig Exp $ 2 1.1 rillig # 3 1.3 rillig # Tests for the special .MAKE.SAVE_DOLLARS variable, which controls whether 4 1.3 rillig # the assignment operator ':=' converts '$$' to a single '$' or keeps it 5 1.3 rillig # as-is. 6 1.3 rillig # 7 1.3 rillig # See also: 8 1.5 rillig # var-op-expand.mk for ':=' in general 9 1.5 rillig # varmisc.mk for parsing the boolean values 10 1.3 rillig 11 1.3 rillig # Initially, the variable .MAKE.SAVE_DOLLARS is undefined. At this point the 12 1.3 rillig # behavior of the assignment operator ':=' depends. NetBSD's usr.bin/make 13 1.3 rillig # preserves the '$$' as-is, while the bmake distribution replaces '$$' with 14 1.3 rillig # '$'. 15 1.3 rillig .if ${.MAKE.SAVE_DOLLARS:Uundefined} != "undefined" 16 1.3 rillig . error 17 1.3 rillig .endif 18 1.3 rillig 19 1.3 rillig 20 1.6 rillig # When dollars are preserved, this setting not only applies to literal 21 1.6 rillig # dollars, but also to those that come indirectly from other expressions. 22 1.5 rillig DOLLARS= $$$$$$$$ 23 1.3 rillig .MAKE.SAVE_DOLLARS= yes 24 1.3 rillig VAR:= ${DOLLARS} 25 1.3 rillig # The reduction from 8 '$' to 4 '$' happens when ${VAR} is evaluated in the 26 1.5 rillig # condition; .MAKE.SAVE_DOLLARS only applies at the moment where the 27 1.5 rillig # assignment is performed using ':='. 28 1.3 rillig .if ${VAR} != "\$\$\$\$" 29 1.3 rillig . error 30 1.3 rillig .endif 31 1.3 rillig 32 1.6 rillig # When dollars are preserved, this setting not only applies to literal 33 1.6 rillig # dollars, but also to those that come indirectly from other expressions. 34 1.6 rillig DOLLARS= $$$$$$$$ 35 1.6 rillig .MAKE.SAVE_DOLLARS= no 36 1.6 rillig VAR:= ${DOLLARS} 37 1.6 rillig .if ${VAR} != "\$\$" 38 1.6 rillig . error 39 1.6 rillig .endif 40 1.6 rillig 41 1.5 rillig # The 'yes' preserves the dollars from the literal. 42 1.3 rillig .MAKE.SAVE_DOLLARS= yes 43 1.3 rillig VAR:= $$$$$$$$ 44 1.3 rillig .if ${VAR} != "\$\$\$\$" 45 1.3 rillig . error 46 1.3 rillig .endif 47 1.3 rillig 48 1.5 rillig # The 'no' converts each '$$' to '$'. 49 1.3 rillig .MAKE.SAVE_DOLLARS= no 50 1.3 rillig VAR:= $$$$$$$$ 51 1.3 rillig .if ${VAR} != "\$\$" 52 1.3 rillig . error 53 1.3 rillig .endif 54 1.3 rillig 55 1.3 rillig # It's even possible to change the dollar interpretation in the middle of 56 1.5 rillig # evaluating an expression, but there is no practical need for it. 57 1.3 rillig .MAKE.SAVE_DOLLARS= no 58 1.3 rillig VAR:= $$$$-${.MAKE.SAVE_DOLLARS::=yes}-$$$$ 59 1.3 rillig .if ${VAR} != "\$--\$\$" 60 1.3 rillig . error 61 1.3 rillig .endif 62 1.1 rillig 63 1.6 rillig # The '$' from the ':U' expressions do not appear as literal '$$' to the 64 1.6 rillig # parser (no matter whether directly or indirectly), they only appear as '$$' 65 1.6 rillig # in the value of an expression, therefore .MAKE.SAVE_DOLLARS doesn't apply 66 1.6 rillig # here. 67 1.4 rillig .MAKE.SAVE_DOLLARS= no 68 1.3 rillig VAR:= ${:U\$\$\$\$}-${.MAKE.SAVE_DOLLARS::=yes}-${:U\$\$\$\$} 69 1.3 rillig .if ${VAR} != "\$\$--\$\$" 70 1.3 rillig . error 71 1.3 rillig .endif 72 1.1 rillig 73 1.4 rillig # Undefining .MAKE.SAVE_DOLLARS does not have any effect, in particular it 74 1.4 rillig # does not restore the default behavior. 75 1.4 rillig .MAKE.SAVE_DOLLARS= no 76 1.4 rillig .undef .MAKE.SAVE_DOLLARS 77 1.4 rillig VAR:= $$$$$$$$ 78 1.4 rillig .if ${VAR} != "\$\$" 79 1.4 rillig . error 80 1.4 rillig .endif 81 1.4 rillig 82 1.4 rillig # Undefining .MAKE.SAVE_DOLLARS does not have any effect, in particular it 83 1.4 rillig # does not restore the default behavior. 84 1.4 rillig .MAKE.SAVE_DOLLARS= yes 85 1.4 rillig .undef .MAKE.SAVE_DOLLARS 86 1.4 rillig VAR:= $$$$$$$$ 87 1.4 rillig .if ${VAR} != "\$\$\$\$" 88 1.4 rillig . error 89 1.4 rillig .endif 90 1.4 rillig 91 1.6 rillig # The variable '.MAKE.SAVE_DOLLARS' not only affects literal '$$' on the 92 1.6 rillig # right-hand side of the assignment operator ':=', it also affects dollars 93 1.6 rillig # in indirect expressions. 94 1.6 rillig # 95 1.6 rillig # In this example, it affects the command in CMD itself, not the result of 96 1.6 rillig # running that command. 97 1.6 rillig .MAKE.SAVE_DOLLARS= no 98 1.6 rillig CMD= echo '$$$$$$$$' 99 1.6 rillig VAR:= ${CMD:sh} 100 1.6 rillig .if ${VAR} != "\$\$" 101 1.6 rillig . error 102 1.6 rillig .endif 103 1.6 rillig 104 1.6 rillig .MAKE.SAVE_DOLLARS= yes 105 1.6 rillig CMD= echo '$$$$$$$$' 106 1.6 rillig VAR:= ${CMD:sh} 107 1.6 rillig .if ${VAR} != "\$\$\$\$" 108 1.6 rillig . error 109 1.6 rillig .endif 110 1.6 rillig 111 1.7 rillig 112 1.7 rillig # In the modifier ':@var@body@', .MAKE.SAVE_DOLLARS does not affect the body. 113 1.7 rillig # In both cases, each '$$' is replaced with a single '$', no matter whether 114 1.7 rillig # directly or indirectly via another expression. 115 1.7 rillig .MAKE.SAVE_DOLLARS= no 116 1.7 rillig DOLLARS= $$$$$$$$ 117 1.7 rillig VAR:= ${word:L:@word@$$$$$$$$-${DOLLARS}@} 118 1.7 rillig .if ${VAR} != "\$\$-\$\$" 119 1.7 rillig . error 120 1.7 rillig .endif 121 1.7 rillig 122 1.7 rillig .MAKE.SAVE_DOLLARS= yes 123 1.7 rillig DOLLARS= $$$$$$$$ 124 1.7 rillig VAR:= ${word:L:@word@$$$$$$$$-${DOLLARS}@} 125 1.7 rillig .if ${VAR} != "\$\$-\$\$" 126 1.7 rillig . error 127 1.7 rillig .endif 128 1.7 rillig 129 1.7 rillig 130 1.1 rillig all: 131
Indexes created Thu Oct 02 10:09:58 GMT 2025