1# $NetBSD: cond-undef-lint.mk,v 1.8 2025/01/11 21:21:33 rillig Exp $ 2# 3# Tests for defined and undefined variables in .if conditions, in lint mode. 4# 5# As of 2020-09-14, lint mode contains experimental code for printing 6# accurate error messages in case of undefined variables, instead of the 7# wrong "Malformed condition". 8# 9# See also: 10# opt-debug-lint.mk 11 12.MAKEFLAGS: -dL 13 14# DEF is defined, UNDEF is not. 15DEF= defined 16 17# An expression based on a defined variable is fine. 18.if !${DEF} 19. error 20.endif 21 22# Since the condition fails to evaluate, neither of the branches is taken. 23# expect+1: Variable "UNDEF" is undefined 24.if ${UNDEF} 25. error 26.else 27. error 28.endif 29 30# The variable name depends on the undefined variable, which is probably a 31# mistake. The variable UNDEF, as used here, can be easily turned into 32# an expression that is always defined, using the :U modifier. 33# 34# expect+1: Variable "VAR." is undefined 35.if ${VAR.${UNDEF}} 36. error 37.else 38. error 39.endif 40 41# The inner variable DEF is defined, but the resulting name VAR.defined 42# refers to an undefined variable, thus an error message. 43# 44# expect+1: Variable "VAR.defined" is undefined 45.if ${VAR.${DEF}} 46. error 47.else 48. error 49.endif 50 51 52# Variables that are referenced indirectly may be undefined in a condition. 53# 54# A practical example for this is CFLAGS, which consists of CWARNS, COPTS 55# and a few others. Just because these nested variables are not defined, 56# this does not make the condition invalid. 57# 58# The crucial point is that at the point where the variable appears in the 59# condition, there is no way to influence the definedness of the nested 60# variables. In particular, there is no modifier that would turn undefined 61# nested variables into empty strings, as an equivalent to the :U modifier. 62INDIRECT= ${NESTED_UNDEF} ${NESTED_DEF} 63NESTED_DEF= nested-defined 64 65# Since NESTED_UNDEF is not controllable at this point, it must not generate 66# an error message, and it doesn't do so, since 2020-09-14. 67.if !${INDIRECT} 68. error 69.endif 70