Teach bsd.lib.mk to auto generate a version map file based on

a set of symbol definitions (VERSION_DEF) and symbol mappings
(SYMBOL_MAPS).

Add an awk script to generate the version map.

Suggested by:	ru
Helped by:	ru
Reviewed by:	ru

1 files changed, 40 insertions, 0 deletions

diff --git a/share/mk/bsd.lib.mk b/share/mk/bsd.lib.mk
index c60c133..02f1d46 100644
--- a/share/mk/bsd.lib.mk
+++ b/share/mk/bsd.lib.mk
@@ -99,6 +99,46 @@ PO_FLAG=-pg
 
 all: objwarn
 
+# Generate the version map given the version definitions
+# and symbol maps.
+.if !empty(VERSION_DEF) && !empty(SYMBOL_MAPS)
+# Find the awk script that generates the version map.
+VERSION_GEN?=	version_gen.awk
+VERSION_MAP?=	Version.map
+
+# Compute the make's -m path.
+_mpath=
+_oarg=
+.for _arg in ${.MAKEFLAGS}
+.if ${_oarg} == "-m"
+_mpath+= ${_arg}
+.endif
+_oarg=  ${_arg}
+.endfor
+_mpath+= /usr/share/mk
+
+# Look up ${VERSION_GEN} in ${_mpath}.
+_vgen=
+.for path in ${_mpath}
+.if empty(_vgen)
+.if exists(${path}/${VERSION_GEN})
+_vgen=  ${path}/${VERSION_GEN}
+.endif
+.endif
+.endfor
+
+${VERSION_MAP}:
+	awk -v vfile=${VERSION_DEF} -f ${_vgen} ${SYMBOL_MAPS} \
+	    > ${.TARGET}
+.endif	# !empty(VERSION_DEF) && !empty(SYMBOL_MAPS)
+
+# Allow librararies to specify their own version map or have it
+# automatically generated (see above).
+.if !empty(VERSION_MAP)
+${SHLIB_NAME}:	${VERSION_MAP}
+LDFLAGS+=	-Wl,--version-script=${VERSION_MAP}
+.endif
+
 .if defined(LIB) && !empty(LIB) || defined(SHLIB_NAME)
 OBJS+=		${SRCS:N*.h:R:S/$/.o/}
 .endif