Index: /usr/ports/devel/gflags/Makefile
===================================================================
--- /usr/ports/devel/gflags/Makefile	(revision 423642)
+++ /usr/ports/devel/gflags/Makefile	(working copy)
@@ -24,4 +24,12 @@
 
 SHEBANG_FILES=	src/gflags_completions.sh
 
+post-install:
+	${CP} ${WRKSRC}/libgflags.pc.in ${STAGEDIR}${PREFIX}/libdata/pkgconfig/libgflags.pc
+	@${REINPLACE_CMD} -i '' \
+		-e 's|@prefix@|${PREFIX}|g' \
+		-e 's|@version@|${DISTVERSION}|g' \
+		${STAGEDIR}${PREFIX}/libdata/pkgconfig/libgflags.pc
+
+
 .include <bsd.port.mk>
Index: /usr/ports/devel/gflags/files/patch-libgflags.pc.in
===================================================================
--- /usr/ports/devel/gflags/files/patch-libgflags.pc.in	(nonexistent)
+++ /usr/ports/devel/gflags/files/patch-libgflags.pc.in	(working copy)
@@ -0,0 +1,13 @@
+--- libgflags.pc.in.orig	2016-06-20 14:46:51 UTC
++++ libgflags.pc.in
+@@ -0,0 +1,10 @@
++prefix=@prefix@
++exec_prefix=${prefix}
++libdir=${exec_prefix}/lib
++includedir=${prefix}/include
++
++Name: libgflags
++Description: Commandline flags module for C++
++Version: @version@
++Libs: -L${libdir} -lgflags
++Cflags: -I${includedir}
Index: /usr/ports/devel/gflags/pkg-plist
===================================================================
--- /usr/ports/devel/gflags/pkg-plist	(revision 423642)
+++ /usr/ports/devel/gflags/pkg-plist	(working copy)
@@ -14,3 +14,4 @@
 lib/libgflags_nothreads.so
 lib/libgflags_nothreads.so.2
 lib/libgflags_nothreads.so.2.1.2
+libdata/pkgconfig/libgflags.pc