directive-ifmake.mk revision 1.12
1 # $NetBSD: directive-ifmake.mk,v 1.12 2023/11/19 21:47:52 rillig Exp $ 2 # 3 # Tests for the .ifmake directive, which provides a shortcut for asking 4 # whether a certain target is requested to be made from the command line. 5 # 6 # TODO: Describe why the shortcut may be useful (if it's useful at all), 7 # instead of using the more general '.if make(target)'. 8 9 .MAKEFLAGS: first second 10 11 # This is the most basic form. 12 .ifmake first 13 # expect+1: ok: positive condition works 14 . info ok: positive condition works 15 .else 16 . warning positive condition fails 17 .endif 18 19 # The '!' is interpreted as 'not'. A possible alternative interpretation of 20 # this condition is whether the target named "!first" was requested. To 21 # distinguish these cases, see the next test. 22 .ifmake !first 23 . warning unexpected 24 .else 25 # expect+1: ok: negation works 26 . info ok: negation works 27 .endif 28 29 # See if the exclamation mark really means "not", or if it is just part of 30 # the target name. Since it means 'not', the two exclamation marks are 31 # effectively ignored, and 'first' is indeed a requested target. If the 32 # exclamation mark were part of the name instead, the name would be '!!first', 33 # and such a target was not requested to be made. 34 .ifmake !!first 35 # expect+1: ok: double negation works 36 . info ok: double negation works 37 .else 38 . warning double negation fails 39 .endif 40 41 # Multiple targets can be combined using the && and || operators. 42 .ifmake first && second 43 # expect+1: ok: both mentioned 44 . info ok: both mentioned 45 .else 46 . warning && does not work as expected 47 .endif 48 49 # Negation also works in complex conditions. 50 .ifmake first && !unmentioned 51 # expect+1: ok: only those mentioned 52 . info ok: only those mentioned 53 .else 54 . warning && with ! does not work as expected 55 .endif 56 57 # Using the .MAKEFLAGS special dependency target, arbitrary command 58 # line options can be added at parse time. This means that it is 59 # possible to extend the targets to be made. 60 .MAKEFLAGS: late-target 61 .ifmake late-target 62 # expect+1: Targets can even be added at parse time. 63 . info Targets can even be added at parse time. 64 .else 65 . info No, targets cannot be added at parse time anymore. 66 .endif 67 68 # Numbers are interpreted as numbers, no matter whether the directive is 69 # a plain .if or an .ifmake. 70 .ifmake 0 71 . error 72 .endif 73 .ifmake 1 74 .else 75 . error 76 .endif 77 78 # A condition that consists of an expression only (without any 79 # comparison operator) can be used with .if and the other .ifxxx directives. 80 .ifmake ${:Ufirst} 81 # expect+1: ok 82 . info ok 83 .else 84 . error 85 .endif 86 87 88 # As an edge case, a target can actually be named "!first" on the command 89 # line. There is no way to define a target of this name though since in a 90 # dependency line, a plain '!' is interpreted as a dependency operator. 91 92 .MAKEFLAGS: !edge 93 .ifmake edge 94 . error 95 .endif 96 97 # The '\!edge' in the following condition is parsed as a bare word. For such 98 # a bare word, there is no escaping mechanism so the backslash passes through. 99 # Since the condition function 'make' accepts a pattern instead of a plain 100 # target name, the '\' is finally discarded in Str_Match. 101 .ifmake \!edge 102 .else 103 . error 104 .endif 105 106 # In a dependency line, a plain '!' is interpreted as a dependency operator 107 # (the other two are ':' and '::'). If the '!' is escaped by a '\', as 108 # implemented in ParseDependencyTargetWord, the additional backslash is never 109 # removed though. The target name thus becomes '\!edge' instead of the 110 # intended '!edge'. Defining a target whose name contains a '!' will either 111 # require additional tricks, or it may even be impossible. 112 113 first second unmentioned late-target \!edge: 114 : $@ 115
Indexes created Sat Oct 18 17:09:52 GMT 2025