Make it harder to specify invalid LIBADD by causing values without

corresponding DPADD_<lib> variables to produce a useful error message.

Differential Revision:	https://reviews.freebsd.org/D2295
Reviewed by:	bapt
Sponsored by:	DARPA, AFRL

UPDATING

@@ -35,6 +35,11 @@ NOTE TO PEOPLE WHO THINK THAT FreeBSD 11.x IS SLOW:
 	The const qualifier has been removed from iconv(3) to comply with
 	POSIX.  The ports tree is aware of this from r384038 onwards.
 
+20150416:
+	Libraries specified by LIBADD in Makefiles must have a corresponding
+	DPADD_<lib> variable to ensure correct dependencies.  This is now
+	enforced in src.libnames.mk.
+
 20150324:
 	From legacy ata(4) driver was removed support for SATA controllers
 	supported by more functional drivers ahci(4), siis(4) and mvs(4).

share/mk/src.libnames.mk

@@ -282,10 +282,14 @@ LDADD_gssapi_krb5+=	${LDADD_pthread}
 .if ${_PRIVATELIBS:M${_l}}
 USEPRIVATELIB+=	${_l}
 .endif
-DPADD+=		${DPADD_${_l}}
+DPADD+=		${DPADD_${_l}:Umissing-dpadd_${_l}}
 LDADD+=		${LDADD_${_l}}
 .endfor
 
+.if defined(DPADD) && ${DPADD:Mmissing-dpadd_*}
+.error Missing ${DPADD:Mmissing-dpadd_*:S/missing-dpadd_//:S/^/DPADD_/} variable add "${DPADD:Mmissing-dpadd_*:S/missing-dpadd_//}" to _LIBRARIES, _INTERNALLIBS, or _PRIVATELIBS and define "${DPADD:Mmissing-dpadd_*:S/missing-dpadd_//:S/^/LIB/:tu}".
+.endif
+
 .if defined(USEPRIVATELIB)
 LDFLAGS+=	-rpath ${LIBPRIVATEDIR}
 .endif