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Diffstat (limited to 'unit-tests/varmod-assign-shell.mk')
| -rw-r--r-- | unit-tests/varmod-assign-shell.mk | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/unit-tests/varmod-assign-shell.mk b/unit-tests/varmod-assign-shell.mk new file mode 100644 index 000000000000..d03692942d5b --- /dev/null +++ b/unit-tests/varmod-assign-shell.mk @@ -0,0 +1,36 @@ +# $NetBSD: varmod-assign-shell.mk,v 1.4 2022/01/10 20:32:29 rillig Exp $ +# +# Tests for the variable modifier '::!=', which assigns the output of a shell +# command to the variable, but only if the command exited successfully. This +# is different from the other places that capture the output of an external +# command (variable assignment operator '!=', expression modifier ':sh', +# expression modifier ':!...!'), which also use the output when the shell +# command fails or crashes. +# +# The variable modifier '::!=' and its close relatives have been around since +# var.c 1.45 from 2000-06-01. +# +# Before 2020.08.25.21.16.53, the variable modifier '::!=' had a bug for +# unsuccessful commands, it put the previous value of the variable into the +# error message instead of the command that was executed. That's where the +# counterintuitive error message 'make: "previous" returned non-zero status' +# comes from. +# +# BUGS +# Even though the variable modifier '::!=' produces an error message, +# the exit status of make is still 0. +# +# Having an error message instead of a warning like for the variable +# assignment operator '!=' is another unnecessary inconsistency. + +DIRECT= previous +DIRECT!= echo output; false + +ASSIGNED= previous +.MAKEFLAGS: -dv # to see the actual command +_:= ${ASSIGNED::!=echo output; ${:Ufalse}} +.MAKEFLAGS: -d0 + +all: + @echo DIRECT=${DIRECT:Q} + @echo ASSIGNED=${ASSIGNED:Q} |