Added bsd.pkg.help.mk, which provides the "help" target.

Since more and more files follow the convention of documenting variables
in a common format, it makes sense to be able to get the documentation
of a single variable by simple means, instead of searching through the
whole mk/ directory.

Try "make help TOPIC=CONFIGURE_DIRS" for an example.

2 files changed, 67 insertions, 2 deletions

diff --git a/mk/bsd.pkg.help.mk b/mk/bsd.pkg.help.mk
new file mode 100644
index 00000000000..bd186bf8d94
--- /dev/null
+++ b/mk/bsd.pkg.help.mk
@@ -0,0 +1,62 @@
+# $NetBSD: bsd.pkg.help.mk,v 1.1 2006/08/02 09:46:22 rillig Exp $
+#
+
+# This is the integrated pkgsrc online help system. To query for the
+# meaning of a variable, run "make help TOPIC=VARNAME". All variables from
+# certain pkgsrc Makefile fragments that have inline comments are eligible
+# for querying.
+
+.if !defined(_PKGSRC_HELP_MK)
+_PKGSRC_HELP_MK=	# defined
+
+_HELP_FILES=		# empty
+_HELP_FILES+=		mk/defaults/mk.conf
+_HELP_FILES+=		mk/bsd.prefs.mk
+_HELP_FILES+=		mk/bsd.pkg.mk
+_HELP_FILES+=		mk/*/*-vars.mk
+
+_HELP_AWK= \
+	BEGIN {								\
+		hline = "===============";				\
+		hline = hline hline hline hline hline;			\
+		found = 0;						\
+		var = 0; comment = 0; n = 0; lines[n++] = hline;	\
+	}								\
+	/./ {								\
+		lines[n++] = $$0;					\
+	}								\
+	($$1 == VARNAME"?=") || ($$1 == "\#"VARNAME"=") {		\
+		var = 1;						\
+	}								\
+	/^\#/ {								\
+		comment = 1;						\
+	}								\
+	/^$$/ {								\
+		if (var == 1 && comment == 1) {				\
+			found = 1;					\
+			for (i = 0; i < n; i++) { print lines[i]; }	\
+		}							\
+		var = 0; comment = 0; n = 0; lines[n++] = hline;	\
+	}								\
+	END {								\
+		if (found) {						\
+			print hline;					\
+		} else {						\
+			print "No help found for " VARNAME ".";		\
+		}							\
+	}
+
+.if !defined(TOPIC) && defined(VARNAME)
+TOPIC=		${VARNAME}
+.endif
+
+help:
+.if !defined(TOPIC)
+	@${ECHO} "usage: "${MAKE:Q}" help TOPIC=<VARNAME>" 1>&2
+.else
+	@set -e; cd ${PKGSRCDIR};					\
+	{ for i in ${_HELP_FILES}; do ${CAT} "$$i"; ${ECHO} ""; done; }	\
+	| ${AWK} -v VARNAME=${TOPIC} '${_HELP_AWK:M*}'
+.endif
+
+.endif
diff --git a/mk/bsd.pkg.mk b/mk/bsd.pkg.mk
index 96075aa8451..aa96c02345b 100644
--- a/mk/bsd.pkg.mk
+++ b/mk/bsd.pkg.mk
@@ -1,4 +1,4 @@
-#	$NetBSD: bsd.pkg.mk,v 1.1878 2006/07/27 21:46:45 jlam Exp $
+#	$NetBSD: bsd.pkg.mk,v 1.1879 2006/08/02 09:46:22 rillig Exp $
 #
 # This file is in the public domain.
 #
@@ -1017,6 +1017,9 @@ changes-entry:
 	${ECHO} ${_CTYPE1}${_CTYPE2}${_CTYPE3} >> ${PKGSRC_CHANGES:Q}
 
 .include "${PKGSRCDIR}/mk/internal/build-defs-message.mk"
-.if make(debug)
+.if make(debug) || make(build-env)
 .include "${PKGSRCDIR}/mk/bsd.pkg.debug.mk"
 .endif
+.if make(help)
+.include "${PKGSRCDIR}/mk/bsd.pkg.help.mk"
+.endif