cond-func.mk revision 1.10
1 # $NetBSD: cond-func.mk,v 1.10 2021/12/28 22:13:56 rillig Exp $ 2 # 3 # Tests for those parts of the functions in .if conditions that are common 4 # among several functions. 5 # 6 # The below test uses the function defined(...) since it has no side-effects, 7 # the other functions (except empty(...)) would work equally well. The 8 # function empty is special because it uses a different parsing algorithm for 9 # its argument. 10 11 DEF= defined 12 ${:UA B}= variable name with spaces 13 ${:UVAR(value)}= variable name with parentheses 14 ${:UVAR{value}}= variable name with balanced braces 15 16 # Really strange variable names must be given indirectly via another variable, 17 # so that no unbalanced braces appear in the top-level expression. 18 VARNAME_UNBALANCED_BRACES= VAR{{{value 19 ${VARNAME_UNBALANCED_BRACES}= variable name with unbalanced braces 20 21 .if !defined(DEF) 22 . error 23 .endif 24 25 # Horizontal whitespace (space tab) after the opening parenthesis is ignored. 26 .if !defined( DEF) 27 . error 28 .endif 29 30 # Horizontal whitespace (space tab) before the closing parenthesis is ignored. 31 .if !defined(DEF ) 32 . error 33 .endif 34 35 # The argument of a function must not directly contain whitespace. 36 .if !defined(A B) 37 . error 38 .endif 39 40 # If necessary, the whitespace can be generated by a variable expression. 41 .if !defined(${:UA B}) 42 . error 43 .endif 44 45 # Characters that could be mistaken for operators must not appear directly 46 # in a function argument. As with whitespace, these can be generated 47 # indirectly. 48 # 49 # It's not entirely clear why these characters are forbidden. 50 # The most plausible reason seems to be typo detection. 51 .if !defined(A&B) 52 . error 53 .endif 54 .if !defined(A|B) 55 . error 56 .endif 57 58 # Even parentheses may appear in variable names. 59 # They must be balanced though. 60 .if !defined(VAR(value)) 61 . error 62 .endif 63 64 # Braces do not have any special meaning when parsing arguments. 65 .if !defined(VAR{value}) 66 . error 67 .endif 68 69 # Braces do not have any special meaning when parsing arguments. 70 # They don't need to be balanced. 71 .if !defined(VAR{{{value) 72 . error 73 .endif 74 75 # There may be spaces around the operators and parentheses, and even 76 # inside the parentheses. The spaces inside the parentheses are not 77 # allowed for the empty() function (see cond-func-empty.mk), therefore 78 # they are typically omitted for the other functions as well. 79 .if ! defined ( DEF ) 80 . error 81 .endif 82 83 # The following condition is interpreted as defined(A) && defined(B). 84 # In lack of a function call expression, each kind of .if directive has a 85 # default function that is called when a bare word is parsed. For the plain 86 # .if directive, this function is defined(); see "struct If ifs" in cond.c. 87 .if A&B 88 . error 89 .endif 90 91 .if defined() 92 . error 93 .else 94 . info The empty variable is never defined. 95 .endif 96 97 # The plain word 'defined' is interpreted as '!empty(defined)'. 98 # That variable is not defined (yet). 99 .if defined 100 . error 101 .else 102 . info A plain function name is parsed as !empty(...). 103 .endif 104 105 # If a variable named 'defined' is actually defined, the bare word 'defined' 106 # is interpreted as 'defined(defined)', and the condition evaluates to true. 107 defined= # defined but empty 108 .if defined 109 . info A plain function name is parsed as !empty(...). 110 .else 111 . error 112 .endif 113 114 # A plain symbol name may start with one of the function names, in this case 115 # 'defined'. 116 .if defined-var 117 . error 118 .else 119 . info Symbols may start with a function name. 120 .endif 121 122 defined-var= # defined but empty 123 .if defined-var 124 . info Symbols may start with a function name. 125 .else 126 . error 127 .endif 128 129 # Missing closing parenthesis when parsing the function argument. 130 .if defined( 131 . error 132 .else 133 . error 134 .endif 135
Indexes created Mon Sep 29 21:09:56 GMT 2025