41 lines
1018 B
Makefile
41 lines
1018 B
Makefile
# $NetBSD: opt-define.mk,v 1.4 2022/06/12 14:27:06 rillig Exp $
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#
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# Tests for the -D command line option, which defines global variables to the
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# value 1, like in the C preprocessor.
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.MAKEFLAGS: -DVAR
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# The variable has the exact value "1", not "1.0".
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.if ${VAR} != "1"
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. error
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.endif
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# The variable can be overwritten by assigning another value to it. This
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# would not be possible if the variable had been specified on the command line
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# as 'VAR=1' instead of '-DVAR'.
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VAR= overwritten
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.if ${VAR} != "overwritten"
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. error
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.endif
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# The variable can be undefined. If the variable had been defined in the
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# "Internal" or in the "Command" scope instead, undefining it would have no
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# effect.
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.undef VAR
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.if defined(VAR)
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. error
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.endif
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# The C preprocessor allows to define a macro with a specific value. Make
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# behaves differently, it defines a variable with the name 'VAR=value' and the
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# value 1.
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.MAKEFLAGS: -DVAR=value
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.if defined(VAR)
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. error
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.endif
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.if ${VAR=value} != "1"
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. error
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.endif
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all: .PHONY
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