cond-token-plain.mk revision 1.9
1 # $NetBSD: cond-token-plain.mk,v 1.9 2021/01/21 13:52:32 rillig Exp $ 2 # 3 # Tests for plain tokens (that is, string literals without quotes) 4 # in .if conditions. 5 6 .MAKEFLAGS: -dc 7 8 .if ${:Uvalue} != value 9 . error 10 .endif 11 12 # Malformed condition since comment parsing is done in an early phase 13 # and removes the '#' and everything behind it long before the condition 14 # parser gets to see it. 15 # 16 # XXX: The error message is missing for this malformed condition. 17 # The right-hand side of the comparison is just a '"', before unescaping. 18 .if ${:U} != "#hash" 19 . error 20 .endif 21 22 # To get a '#' into a condition, it has to be escaped using a backslash. 23 # This prevents the comment parser from removing it, and in turn, it becomes 24 # visible to CondParser_String. 25 .if ${:U\#hash} != "\#hash" 26 . error 27 .endif 28 29 # Since 2002-12-30, and still as of 2020-09-11, CondParser_Token handles 30 # the '#' specially, even though at this point, there should be no need for 31 # comment handling anymore. The comments are supposed to be stripped off 32 # in a very early parsing phase. 33 # 34 # See https://gnats.netbsd.org/19596 for example makefiles demonstrating the 35 # original problems. This workaround is probably not needed anymore. 36 # 37 # XXX: Missing error message for the malformed condition. The right-hand 38 # side before unescaping is double-quotes, backslash, backslash. 39 .if ${:U\\} != "\\#hash" 40 . error 41 .endif 42 43 # The right-hand side of a comparison is not parsed as a token, therefore 44 # the code from CondParser_Token does not apply to it. 45 # TODO: Explain the consequences. 46 # TODO: Does this mean that more syntactic variants are allowed here? 47 .if ${:U\#hash} != \#hash 48 . error 49 .endif 50 51 # XXX: What is the purpose of treating an escaped '#' in the following 52 # condition as a comment? And why only at the beginning of a token, 53 # just as in the shell? 54 .if 0 \# This is treated as a comment, but why? 55 . error 56 .endif 57 58 # Ah, ok, this can be used to add an end-of-condition comment. But does 59 # anybody really use this? This is neither documented nor obvious since 60 # the '#' is escaped. It's much clearer to write a comment in the line 61 # above the condition. 62 .if ${0 \# comment :?yes:no} != no 63 . error 64 .endif 65 .if ${1 \# comment :?yes:no} != yes 66 . error 67 .endif 68 69 # Usually there is whitespace around the comparison operator, but this is 70 # not required. 71 .if ${UNDEF:Uundefined}!=undefined 72 . error 73 .endif 74 .if ${UNDEF:U12345}>12345 75 . error 76 .endif 77 .if ${UNDEF:U12345}<12345 78 . error 79 .endif 80 .if (${UNDEF:U0})||0 81 . error 82 .endif 83 84 # Only the comparison operator terminates the comparison operand, and it's 85 # a coincidence that the '!' is both used in the '!=' comparison operator 86 # as well as for negating a comparison result. 87 # 88 # The boolean operators '&' and '|' don't terminate a comparison operand. 89 .if ${:Uvar}&&name != "var&&name" 90 . error 91 .endif 92 .if ${:Uvar}||name != "var||name" 93 . error 94 .endif 95 96 # A bare word may appear alone in a condition, without any comparison 97 # operator. It is implicitly converted into defined(bare). 98 .if bare 99 . error 100 .else 101 . info A bare word is treated like defined(...), and the variable $\ 102 'bare' is not defined. 103 .endif 104 105 VAR= defined 106 .if VAR 107 . info A bare word is treated like defined(...). 108 .else 109 . error 110 .endif 111 112 # Bare words may be intermixed with variable expressions. 113 .if V${:UA}R 114 . info ok 115 .else 116 . error 117 .endif 118 119 # In bare words, even undefined variables are allowed. Without the bare 120 # words, undefined variables are not allowed. That feels inconsistent. 121 .if V${UNDEF}AR 122 . info Undefined variables in bare words expand to an empty string. 123 .else 124 . error 125 .endif 126 127 .if 0${:Ux00} 128 . error 129 .else 130 . info Numbers can be composed from literals and variable expressions. 131 .endif 132 133 .if 0${:Ux01} 134 . info Numbers can be composed from literals and variable expressions. 135 .else 136 . error 137 .endif 138 139 # If the right-hand side is missing, it's a parse error. 140 .if "" == 141 . error 142 .else 143 . error 144 .endif 145 146 # If the left-hand side is missing, it's a parse error as well, but without 147 # a specific error message. 148 .if == "" 149 . error 150 .else 151 . error 152 .endif 153 154 # The '\\' is not a line continuation. Neither is it an unquoted string 155 # literal. Instead, it is parsed as a function argument (ParseFuncArg), 156 # and in that context, the backslash is just an ordinary character. The 157 # function argument thus stays '\\' (2 backslashes). This string is passed 158 # to FuncDefined, and since there is no variable named '\\', the condition 159 # evaluates to false. 160 .if \\ 161 . error 162 .else 163 . info The variable '\\' is not defined. 164 .endif 165 166 ${:U\\\\}= backslash 167 .if \\ 168 . info Now the variable '\\' is defined. 169 .else 170 . error 171 .endif 172 173 # Anything that doesn't start with a double quote is considered a "bare word". 174 # Strangely, a bare word may contain double quotes inside. Nobody should ever 175 # depend on this since it may well be unintended. See CondParser_String. 176 .if "unquoted\"quoted" != unquoted"quoted 177 . error 178 .endif 179 180 # See cond-token-string.mk for similar tests where the condition is enclosed 181 # in "quotes". 182 183 all: 184 @:; 185
Indexes created Fri Oct 17 23:09:53 GMT 2025