1# $NetBSD: directive-export-impl.mk,v 1.3 2021/04/03 23:08:30 rillig Exp $
2#
3# Test for the implementation of exporting variables to child processes.
4# This involves marking variables for export, actually exporting them,
5# or marking them for being re-exported.
6#
7# See also:
8#	Var_Export
9#	ExportVar
10#	VarExportedMode (global)
11#	VarFlags.exported (per variable)
12#	VarFlags.reexport (per variable)
13#	VarExportMode (per call of Var_Export and ExportVar)
14
15: ${:U:sh}			# side effect: initialize .SHELL
16
17.MAKEFLAGS: -dcpv
18
19# This is a variable that references another variable.  At this point, the
20# other variable is still undefined.
21UT_VAR=		<${REF}>
22
23# At this point, ExportVar("UT_VAR", VEM_PLAIN) is called.  Since the
24# variable value refers to another variable, ExportVar does not actually
25# export the variable but only marks it as VarFlags.exported and
26# VarFlags.reexport.  After that, ExportVars registers the variable name in
27# .MAKE.EXPORTED.  That's all for now.
28.export UT_VAR
29
30# The following expression has both flags 'exported' and 'reexport' set.
31# These flags do not show up anywhere, not even in the debug log.
32: ${UT_VAR:N*}
33
34# At the last moment before actually forking off the child process for the
35# :!...! modifier, Cmd_Exec calls Var_ReexportVars to have all relevant
36# variables exported.  Since this variable has both of the above-mentioned
37# flags set, it is actually exported to the environment.  The variable flags
38# are not modified though, since the next time the :!...! modifier is
39# evaluated, the referenced variables could have changed, therefore the
40# variable will be exported anew for each ':sh' modifier, ':!...!' modifier,
41# '!=' variable assignment.
42.if ${:!echo "\$UT_VAR"!} != "<>"
43.  error
44.endif
45
46# The following expression still has 'exported' and 'reexport' set.
47# These flags do not show up anywhere though, not even in the debug log.
48# These flags means that the variable is still marked as being re-exported
49# for each child process.
50: ${UT_VAR:N*}
51
52# Now the referenced variable gets defined.  This does not influence anything
53# in the process of exporting the variable value, though.
54REF=		defined
55
56# Nothing surprising here.  The variable UT_VAR gets exported, and this time,
57# REF is defined and gets expanded into the exported environment variable.
58.if ${:!echo "\$UT_VAR"!} != "<defined>"
59.  error
60.endif
61
62all:
63.MAKEFLAGS: -d0
64