Module Name: src
Committed By: rillig
Date: Mon Sep 7 19:17:36 UTC 2020
Modified Files:
src/usr.bin/make/unit-tests: comment.exp comment.mk
Log Message:
make(1): extend and explain the test for comments
To generate a diff of this commit:
cvs rdiff -u -r1.1 -r1.2 src/usr.bin/make/unit-tests/comment.exp \
src/usr.bin/make/unit-tests/comment.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/comment.exp
diff -u src/usr.bin/make/unit-tests/comment.exp:1.1 src/usr.bin/make/unit-tests/comment.exp:1.2
--- src/usr.bin/make/unit-tests/comment.exp:1.1 Thu Aug 21 13:44:51 2014
+++ src/usr.bin/make/unit-tests/comment.exp Mon Sep 7 19:17:36 2020
@@ -1,5 +1,6 @@
-comment testing start
-this is foo
-This is how a comment looks: # comment
-comment testing done
+echo This is a shell comment: # comment
+This is a shell comment:
+echo This is not a shell comment: '# comment'
+This is not a shell comment: # comment
+A shell comment can#not start in the middle of a word.
exit status 0
Index: src/usr.bin/make/unit-tests/comment.mk
diff -u src/usr.bin/make/unit-tests/comment.mk:1.1 src/usr.bin/make/unit-tests/comment.mk:1.2
--- src/usr.bin/make/unit-tests/comment.mk:1.1 Thu Aug 21 13:44:51 2014
+++ src/usr.bin/make/unit-tests/comment.mk Mon Sep 7 19:17:36 2020
@@ -1,31 +1,74 @@
-# This is a comment
-.if ${MACHINE_ARCH} == something
-FOO=bar
-.endif
-
-#\
- Multiline comment
+# $NetBSD: comment.mk,v 1.2 2020/09/07 19:17:36 rillig Exp $
+#
+# Demonstrate how comments are written in makefiles.
-BAR=# defined
-FOOBAR= # defined
+# This is a comment.
-# This is an escaped comment \
-that keeps going until the end of this line
+#\
+This is a multiline comment.
-# Another escaped comment \
+# Another multiline comment \
that \
goes \
-on
+on and on.
+
+ # Comments can be indented, but that is rather unusual.
+
+ # Comments can be indented with a tab.
+ # These are not shell commands, they are just makefile comments.
+
+.if 1 # There can be comments after conditions.
+.endif # And after the closing directive.
+
+VAR= # This comment makes the variable value empty.
+.if ${VAR} != ""
+. error
+.endif
+
+# The comment does not need to start at the beginning of a word (as in the
+# shell), it can start anywhere.
+VAR=# defined but empty
+
+# The space before the comment is always trimmed.
+VAR= value
+.if ${VAR} != "value"
+. error
+.endif
# This is NOT an escaped comment due to the double backslashes \\
-all: hi foo bar
- @echo comment testing done
+VAR= not part of the comment
+.if ${VAR} != "not part of the comment"
+. error
+.endif
-hi:
- @echo comment testing start
+# To escape a comment sign, precede it with a backslash.
+VAR= \# # Both in the assignment.
+.if ${VAR} != "\#" # And in the comparison.
+. error
+.endif
+
+# Since 2012-03-24 the variable modifier :[#] does not need to be escaped.
+# To keep the parsing code simple, any "[#" does not start a comment, even
+# outside of a variable expression.
+WORDS= ${VAR:[#]} [#
+.if ${WORDS} != "1 [#"
+. error
+.endif
-foo:
- @echo this is $@
+# An odd number of comment signs makes a line continuation, \\\
+no matter if it is 3 or 5 \\\\\
+or 9 backslashes. \\\\\\\\\
+This is the last line of the comment.
+VAR= no comment anymore
+.if ${VAR} != "no comment anymore"
+. error
+.endif
-bar:
- @echo This is how a comment looks: '# comment'
+all:
+# In the commands associated with a target, the '#' does not start a makefile
+# comment. The '#' is just passed to the shell, like any ordinary character.
+ echo This is a shell comment: # comment
+# If the '#' were to start a makefile comment, the following shell command
+# would have unbalanced quotes.
+ echo This is not a shell comment: '# comment'
+ @echo A shell comment can#not start in the middle of a word.
