varmod-defined.mk revision 1.13
1 # $NetBSD: varmod-defined.mk,v 1.13 2022/08/24 20:22:10 rillig Exp $ 2 # 3 # Tests for the :D variable modifier, which returns the given string 4 # if the variable is defined. It is closely related to the :U modifier. 5 6 # Force the test results to be independent of the default value of this 7 # setting, which is 'yes' for NetBSD's usr.bin/make but 'no' for the bmake 8 # distribution and pkgsrc/devel/bmake. 9 .MAKE.SAVE_DOLLARS= yes 10 11 DEF= defined 12 .undef UNDEF 13 14 # Since DEF is defined, the value of the expression is "value", not 15 # "defined". 16 # 17 .if ${DEF:Dvalue} != "value" 18 . error 19 .endif 20 21 # Since UNDEF is not defined, the "value" is ignored. Instead of leaving the 22 # expression undefined, it is set to "", exactly to allow the expression to 23 # be used in .if conditions. In this place, other undefined expressions 24 # would generate an error message. 25 # XXX: Ideally the error message would be "undefined variable", but as of 26 # 2020-08-25 it is "Malformed conditional". 27 # 28 .if ${UNDEF:Dvalue} != "" 29 . error 30 .endif 31 32 # The modifier text may contain plain text as well as expressions. 33 # 34 .if ${DEF:D<${DEF}>} != "<defined>" 35 . error 36 .endif 37 38 # Special characters that would be interpreted differently can be escaped. 39 # These are '}' (the closing character of the expression), ':', '$' and '\'. 40 # Any other backslash sequences are preserved. 41 # 42 # The escaping rules for string literals in conditions are completely 43 # different though. There, any character may be escaped using a backslash. 44 # 45 .if ${DEF:D \} \: \$ \\ \) \n } != " } : \$ \\ \\) \\n " 46 . error 47 .endif 48 49 # Like in several other places in variable expressions, when 50 # ApplyModifier_Defined calls Var_Parse, double dollars lead to a parse 51 # error that is silently ignored. This makes all dollar signs disappear, 52 # except for the last, which is a well-formed variable expression. 53 # 54 .if ${DEF:D$$$$$${DEF}} != "defined" 55 . error 56 .endif 57 58 # Any other text is written without any further escaping. In contrast 59 # to the :M modifier, parentheses and braces do not need to be nested. 60 # Instead, the :D modifier is implemented sanely by parsing nested 61 # expressions as such, without trying any shortcuts. See ApplyModifier_Match 62 # for an inferior variant. 63 # 64 .if ${DEF:D!&((((} != "!&((((" 65 . error 66 .endif 67 68 # The :D modifier is often used in combination with the :U modifier. 69 # It does not matter in which order the :D and :U modifiers appear. 70 .if ${UNDEF:Dyes:Uno} != no 71 . error 72 .endif 73 .if ${UNDEF:Uno:Dyes} != no 74 . error 75 .endif 76 .if ${DEF:Dyes:Uno} != yes 77 . error 78 .endif 79 .if ${DEF:Uno:Dyes} != yes 80 . error 81 .endif 82 83 # Since the variable with the empty name is never defined, the :D modifier 84 # can be used to add comments in the middle of an expression. That 85 # expression always evaluates to an empty string. 86 .if ${:D This is a comment. } != "" 87 . error 88 .endif 89 90 # TODO: Add more tests for parsing the plain text part, to cover each branch 91 # of ApplyModifier_Defined. 92 93 # The :D and :U modifiers behave differently from the :@var@ modifier in 94 # that they preserve dollars in a ':=' assignment. This is because 95 # ApplyModifier_Defined passes the emode unmodified to Var_Parse, unlike 96 # ApplyModifier_Loop, which uses ParseModifierPart, which in turn removes 97 # the keepDollar flag from emode. 98 # 99 # XXX: This inconsistency is documented nowhere. 100 .MAKEFLAGS: -dv 101 8_DOLLARS= $$$$$$$$ 102 VAR:= ${8_DOLLARS} 103 VAR:= ${VAR:D${8_DOLLARS}} 104 VAR:= ${VAR:@var@${8_DOLLARS}@} 105 .MAKEFLAGS: -d0 106 107 108 # Before var.c 1.1030 from 2022-08-24, the following expression caused an 109 # out-of-bounds read when parsing the indirect ':D' modifier. 110 M_U_backslash:= ${:UU\\} 111 .if ${:${M_U_backslash}} != "\\" 112 . error 113 .endif 114 115 116 all: .PHONY 117
Indexes created Tue Sep 30 20:09:53 GMT 2025