+ifdef NO_LUA
+ LUA_MESSAGE := linking without specified Lua support
+ CGIT_CFLAGS += -DNO_LUA
+else
+LUAJIT_CFLAGS := $(shell pkg-config --cflags luajit 2>/dev/null)
+LUAJIT_LIBS := $(shell pkg-config --libs luajit 2>/dev/null)
+LUA_LIBS := $(shell pkg-config --libs lua 2>/dev/null)
+LUA_CFLAGS := $(shell pkg-config --cflags lua 2>/dev/null)
+ifeq (JIT,$(LUA_IMPLEMENTATION))
+ ifeq ($(strip $(LUAJIT_LIBS)),)
+ $(error LuaJIT specified via LUA_IMPLEMENTATION=JIT, but library could not be found.)
+ endif
+ LUA_MESSAGE := linking with selected LuaJIT
+ CGIT_LIBS += $(LUAJIT_LIBS)
+ CGIT_CFLAGS += $(LUAJIT_CFLAGS)
+else ifeq (VANILLA,$(LUA_IMPLEMENTATION))
+ ifeq ($(strip $(LUA_LIBS)),)
+ $(error Lua specified via LUA_IMPLEMENTATION=VANILLA, but library could not be found.)
+ endif
+ LUA_MESSAGE := linking with selected Lua
+ CGIT_LIBS += $(LUA_LIBS)
+ CGIT_LIBS += $(LUA_CFLAGS)
+else ifneq ($(strip $(LUAJIT_LIBS)),)
+ LUA_MESSAGE := linking with autodetected LuaJIT
+ CGIT_LIBS += $(LUAJIT_LIBS)
+ CGIT_CFLAGS += $(LUAJIT_CFLAGS)
+else ifneq ($(strip $(LUA_LIBS)),)
+ LUA_MESSAGE := linking with autodetected Lua
+ CGIT_LIBS += $(LUA_LIBS)
+ CGIT_CFLAGS += $(LUA_CFLAGS)
+else
+ LUA_MESSAGE := linking without autodetected Lua support
+ NO_LUA := YesPlease
+ CGIT_CFLAGS += -DNO_LUA
+endif
+
+endif
+
+# Add -ldl to linker flags on non-BSD systems.
+ifeq ($(findstring BSD,$(uname_S)),)
+ CGIT_LIBS += -ldl
+endif
+
+