vis: refactor Lua integration

Lua support can now be disabled at compile time using:

 $ make CONFIG_LUA=0

This commit also adds an initial Lua API and provides a few
default hooks.

We now also require Lua >= 5.2 due to the uservalue constructs.
In principle the same functionality could be implemented using
function environments from Lua 5.1.

1 files changed, 10 insertions, 4 deletions

diff --git a/config.mk b/config.mk
index f11e8c1..0391284 100644
--- a/config.mk
+++ b/config.mk
@@ -1,6 +1,7 @@
 # optional features
 HAVE_ACL=0
 HAVE_SELINUX=0
+CONFIG_LUA=1
 
 # vis version
 RELEASE = HEAD
@@ -26,17 +27,22 @@ PREFIX ?= /usr/local
 MANPREFIX = ${PREFIX}/share/man
 SHAREPREFIX = ${PREFIX}/share/vis
 
-CFLAGS_LUA = $(shell pkg-config --cflags lua5.1 2> /dev/null || echo "-I/usr/include/lua5.1")
-CFLAGS_TERMKEY = $(shell pkg-config --cflags termkey 2> /dev/null || echo "")
-CFLAGS_CURSES = $(shell pkg-config --cflags ncursesw 2> /dev/null || echo "-I/usr/include/ncursesw")
+ifeq (${CONFIG_LUA},1)
+	CFLAGS_LUA = $(shell pkg-config --cflags lua5.2 2> /dev/null || echo "-I/usr/include/lua5.2")
+	LDFLAGS_LUA = $(shell pkg-config --libs lua5.2 2> /dev/null || echo "-llua")
+endif
 
-LDFLAGS_LUA = $(shell pkg-config --libs lua5.1 2> /dev/null || echo "-llua")
+CFLAGS_TERMKEY = $(shell pkg-config --cflags termkey 2> /dev/null || echo "")
 LDFLAGS_TERMKEY = $(shell pkg-config --libs termkey 2> /dev/null || echo "-ltermkey")
+
+CFLAGS_CURSES = $(shell pkg-config --cflags ncursesw 2> /dev/null || echo "-I/usr/include/ncursesw")
 LDFLAGS_CURSES = $(shell pkg-config --libs ncursesw 2> /dev/null || echo "-lncursesw")
 
 LIBS = -lm -ldl -lc
 OS = $(shell uname)
 
+CFLAGS += -DCONFIG_LUA=${CONFIG_LUA}
+
 ifeq (${OS},Linux)
 	ifeq (${HAVE_SELINUX},1)
 		CFLAGS += -DHAVE_SELINUX