1*8d5c8e21SSimon J. Gerraty# $NetBSD: directive-export.mk,v 1.12 2024/06/01 10:06:23 rillig Exp $ 22c3632d1SSimon J. Gerraty# 32c3632d1SSimon J. Gerraty# Tests for the .export directive. 406b9b3e0SSimon J. Gerraty# 506b9b3e0SSimon J. Gerraty# See also: 606b9b3e0SSimon J. Gerraty# directive-misspellings.mk 72c3632d1SSimon J. Gerraty 82c3632d1SSimon J. Gerraty# TODO: Implementation 92c3632d1SSimon J. Gerraty 10956e45f6SSimon J. GerratyINDIRECT= indirect 11956e45f6SSimon J. GerratyVAR= value $$ ${INDIRECT} 12956e45f6SSimon J. Gerraty 1306b9b3e0SSimon J. Gerraty# Before 2020-12-13, this unusual expression invoked undefined behavior since 1406b9b3e0SSimon J. Gerraty# it accessed out-of-bounds memory via Var_Export -> ExportVar -> MayExport. 1506b9b3e0SSimon J. Gerraty.export ${:U } 1606b9b3e0SSimon J. Gerraty 17956e45f6SSimon J. Gerraty# A variable is exported using the .export directive. 18956e45f6SSimon J. Gerraty# During that, its value is expanded, just like almost everywhere else. 19956e45f6SSimon J. Gerraty.export VAR 20956e45f6SSimon J. Gerraty.if ${:!env | grep '^VAR'!} != "VAR=value \$ indirect" 21956e45f6SSimon J. Gerraty. error 22956e45f6SSimon J. Gerraty.endif 23956e45f6SSimon J. Gerraty 24956e45f6SSimon J. Gerraty# Undefining a variable that has been exported implicitly removes it from 25956e45f6SSimon J. Gerraty# the environment of all child processes. 26956e45f6SSimon J. Gerraty.undef VAR 27956e45f6SSimon J. Gerraty.if ${:!env | grep '^VAR' || true!} != "" 28956e45f6SSimon J. Gerraty. error 29956e45f6SSimon J. Gerraty.endif 30956e45f6SSimon J. Gerraty 31*8d5c8e21SSimon J. Gerraty# Before var.c 1.1117 from 2024-06-01, a plain ".export" without a syntactical 32*8d5c8e21SSimon J. Gerraty# argument exported all global variables. This case could be triggered 33*8d5c8e21SSimon J. Gerraty# unintentionally by writing a line of the form ".export ${VARNAMES}" to a 34*8d5c8e21SSimon J. Gerraty# makefile, when VARNAMES was an empty list. 35*8d5c8e21SSimon J. Gerraty# expect+1: warning: .export requires an argument. 3606b9b3e0SSimon J. Gerraty.export 37e2eeea75SSimon J. Gerraty 38b0c40a00SSimon J. Gerraty# An empty argument means no additional variables to export. 39b0c40a00SSimon J. Gerraty.export ${:U} 40b0c40a00SSimon J. Gerraty 41b0c40a00SSimon J. Gerraty 42d5e0a182SSimon J. Gerraty# Before a child process is started, whether for the '!=' assignment operator 43d5e0a182SSimon J. Gerraty# or for the ':sh' modifier, all variables that were marked for being exported 44d5e0a182SSimon J. Gerraty# are expanded and then exported. If expanding such a variable requires 45d5e0a182SSimon J. Gerraty# running a child command, the marked-as-exported variables would need to be 46d5e0a182SSimon J. Gerraty# exported first, ending in an endless loop. To avoid this endless loop, 47d5e0a182SSimon J. Gerraty# don't export the variables while preparing a child process, see 48d5e0a182SSimon J. Gerraty# ExportVarEnv. 49b0c40a00SSimon J. GerratyEMPTY_SHELL= ${:sh} 50b0c40a00SSimon J. Gerraty.export EMPTY_SHELL # only marked for export at this point 51b0c40a00SSimon J. Gerraty_!= :;: # Force the variable to be actually exported. 52b0c40a00SSimon J. Gerraty 53b0c40a00SSimon J. Gerraty 5498875883SSimon J. Gerraty# If the '.export' directive exports a variable whose value contains a '$', 5598875883SSimon J. Gerraty# the actual export action is deferred until a subprocess is started, assuming 5698875883SSimon J. Gerraty# that only subprocesses access the environment variables. The ':localtime' 5798875883SSimon J. Gerraty# modifier depends on the 'TZ' environment variable, without any subprocess. 5898875883SSimon J. Gerratyexport TZ=${UTC} 5998875883SSimon J. Gerraty# expect+1: 00:00:00 6098875883SSimon J. Gerraty.info ${%T:L:localtime=86400} 6198875883SSimon J. GerratyINDIRECT_TZ= ${:UAmerica/Los_Angeles} 6298875883SSimon J. GerratyTZ= ${INDIRECT_TZ} 6398875883SSimon J. Gerraty.export TZ 6498875883SSimon J. Gerraty# expect+1: 00:00:00 6598875883SSimon J. Gerraty.info ${%T:L:localtime=86400} 6698875883SSimon J. Gerraty_!= echo 'force exporting the environment variables' 6798875883SSimon J. Gerraty# expect+1: 16:00:00 6898875883SSimon J. Gerraty.info ${%T:L:localtime=86400} 6998875883SSimon J. Gerraty 7098875883SSimon J. Gerraty 712c3632d1SSimon J. Gerratyall: 72