# $NetBSD: cond-func.mk,v 1.1 2020/08/20 17:45:47 rillig Exp $ # # Tests for those parts of the functions in .if conditions that are common # among several functions. # # The below test uses the function defined(...) since it has no side-effects, # the other functions (except empty(...)) would work equally well. DEF= defined ${:UA B}= variable name with spaces ${:UVAR(value)}= variable name with parentheses ${:UVAR{value}}= variable name with braces .if !defined(DEF) .error .endif # Horizontal whitespace after the opening parenthesis is ignored. .if !defined( DEF) .error .endif # Horizontal whitespace before the closing parenthesis is ignored. .if !defined(DEF ) .error .endif # The argument of a function must not directly contain whitespace. .if !defined(A B) .error .endif # If necessary, the whitespace can be generated by a variable expression. .if !defined(${:UA B}) .error .endif # Characters that could be mistaken for operators must not appear directly # in a function argument. As with whitespace, these can be generated # indirectly. # # It's not entirely clear why these characters are forbidden. # The most plausible reason seems to be typo detection. .if !defined(A&B) .error .endif .if !defined(A|B) .error .endif # Even parentheses may appear in variable names. # They must be balanced though. .if !defined(VAR(value)) .error .endif # Braces do not have any special meaning when parsing arguments. .if !defined(VAR{value}) .error .endif all: @:;