Module Name: src
Committed By: rillig
Date: Tue Nov 17 20:08:09 UTC 2020
Modified Files:
src/usr.bin/make/unit-tests: varmod-shell.exp varmod-shell.mk
Log Message:
make(1): document 20-year-old bug in the :!cmd! modifier
To generate a diff of this commit:
cvs rdiff -u -r1.1 -r1.2 src/usr.bin/make/unit-tests/varmod-shell.exp
cvs rdiff -u -r1.3 -r1.4 src/usr.bin/make/unit-tests/varmod-shell.mk
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/usr.bin/make/unit-tests/varmod-shell.exp
diff -u src/usr.bin/make/unit-tests/varmod-shell.exp:1.1 src/usr.bin/make/unit-tests/varmod-shell.exp:1.2
--- src/usr.bin/make/unit-tests/varmod-shell.exp:1.1 Sun Aug 16 12:07:51 2020
+++ src/usr.bin/make/unit-tests/varmod-shell.exp Tue Nov 17 20:08:09 2020
@@ -1 +1,3 @@
+make: "" returned non-zero status
+make: "previous value" returned non-zero status
exit status 0
Index: src/usr.bin/make/unit-tests/varmod-shell.mk
diff -u src/usr.bin/make/unit-tests/varmod-shell.mk:1.3 src/usr.bin/make/unit-tests/varmod-shell.mk:1.4
--- src/usr.bin/make/unit-tests/varmod-shell.mk:1.3 Sun Nov 15 20:20:58 2020
+++ src/usr.bin/make/unit-tests/varmod-shell.mk Tue Nov 17 20:08:09 2020
@@ -1,11 +1,35 @@
-# $NetBSD: varmod-shell.mk,v 1.3 2020/11/15 20:20:58 rillig Exp $
+# $NetBSD: varmod-shell.mk,v 1.4 2020/11/17 20:08:09 rillig Exp $
#
# Tests for the :sh variable modifier, which runs the shell command
# given by the variable value and returns its output.
#
-# TODO: Since when is this modifier available?
+# This modifier has been added on 2000-04-29.
+#
+# See also:
+# ApplyModifier_ShellCommand
# TODO: Implementation
+# The command to be run is enclosed between exclamation marks.
+# The previous value of the expression is irrelevant for this modifier.
+# The :!cmd! modifier turns an undefined expression into a defined one.
+.if ${:!echo word!} != "word"
+. error
+.endif
+
+# If the command exits with non-zero, an error message is printed.
+# XXX: Processing continues as usual though.
+#
+# Since 2000-04-29, the error message mentions the previous
+# value of the expression (which is usually an empty string) instead of the
+# command that was executed. It's strange that such a simple bug could
+# survive such a long time.
+.if ${:!echo word; false!} != "word"
+. error
+.endif
+.if ${:Uprevious value:!echo word; false!} != "word"
+. error
+.endif
+
all:
@:;
