Add initial Lua scripting support

This is preliminary. There are still tons of issues, and any aspect
of scripting may change in the future. I decided to merge this
(preliminary) work now because it makes it easier to develop it, not
because it's done. lua.rst is clear enough about it (plus some
sarcasm).

This requires linking to Lua. Lua has no official pkg-config file, but
there are distribution specific .pc files, all with different names.
Adding a non-pkg-config based configure test was considered, but we'd
rather not.

One major complication is that libquvi links against Lua too, and if
the Lua version is different from mpv's, you will get a crash as soon
as libquvi uses Lua. (libquvi by design always runs when a file is
opened.) I would consider this the problem of distros and whoever
builds mpv, but to make things easier for users, we add a terrible
runtime test to the configure script, which probes whether libquvi
will crash. This is disabled when cross-compiling, but in that case
we hope the user knows what he is doing.

1 files changed, 114 insertions, 0 deletions

diff --git a/configure b/configure
index 482a34aecc..32525f9de9 100755
--- a/configure
+++ b/configure
@@ -293,6 +293,9 @@ Installation directories:
 
 Optional features:
   --disable-encoding     disable encoding functionality [enable]
+  --disable-lua          disable Lua scripting support [autodetect]
+  --lua=LUA              select Lua package which should be autodetected
+                         Choices: 51 51deb 52 52deb luajit
   --disable-libguess     disable libguess [autodetect]
   --enable-terminfo      use terminfo database for key codes [autodetect]
   --enable-termcap       use termcap database for key codes [autodetect]
@@ -485,6 +488,7 @@ _pthreads=auto
 _ass=auto
 _libass_osd=auto
 _rpath=no
+lua=auto
 libpostproc=auto
 libavfilter=auto
 vf_lavfi=auto
@@ -679,6 +683,9 @@ for ac_option do
   --disable-libavresample) _disable_avresample=yes ;;
   --enable-libavresample) _disable_avresample=no   ;;
 
+  --enable-lua)         lua=yes         ;;
+  --disable-lua)        lua=no          ;;
+  --lua=*)              lua_pkg=$(echo $ac_option | cut -d '=' -f 2) ;;
   --enable-lirc)        _lirc=yes       ;;
   --disable-lirc)       _lirc=no        ;;
   --enable-lircc)       _lircc=yes      ;;
@@ -2982,6 +2989,111 @@ fi
 echores "$_pvr"
 
 
+# Note: Lua has no official .pc file, so there are different OS-specific ones.
+# Also, we support luajit, which is compatible to 5.1.
+# The situation is further complicated by distros supporting multiple Lua
+# versions, without ensuring libraries linking to conflicting Lua libs don't
+# cause issues. This is a real problem with libquvi.
+
+cat > $TMPC << EOF
+#include <stdlib.h>
+#include <lua.h>
+#include <lualib.h>
+#include <lauxlib.h>
+EOF
+# abuse $TMPH file as second temp file
+cat > $TMPH << EOF
+void test_lua(void) {
+    lua_State *L = luaL_newstate();
+    lua_pushstring(L, "test");
+    lua_setglobal(L, "test");
+}
+void test_other(void) {
+EOF
+
+# test all other Lua using packages (hack that gives us time)
+if test "$_libquvi4" = yes ; then
+
+echo "#include <quvi/quvi.h>" >> $TMPC
+cat >> $TMPH << EOF
+    quvi_t q;
+    if (quvi_init(&q) == QUVI_OK)
+        quvi_supported(q, "http://nope");
+EOF
+
+fi
+
+if test "$_libquvi9" = yes ; then
+
+echo "#include <quvi.h>" >> $TMPC
+cat >> $TMPH << EOF
+    quvi_t q = quvi_new();
+    if (quvi_ok(q))
+        quvi_supports(q, "http://nope", QUVI_SUPPORTS_MODE_OFFLINE, QUVI_SUPPORTS_TYPE_MEDIA);
+EOF
+
+fi
+
+cat >> $TMPH << EOF
+}
+int main(void) {
+    test_lua();
+    test_other();
+    return 0;
+}
+EOF
+
+cat $TMPH >> $TMPC
+
+test_lua() {
+    # changed by pkg_config_add
+    old_extra_cflags="$extra_cflags"
+    old_libs_mplayer="$libs_mplayer"
+    echocheck "Lua $2 ($1)"
+    if test "$lua" = yes ; then
+        echores "no"
+        return 1
+    fi
+    if test "x$lua_pkg" != "x" && test "$lua_pkg" != "$1" ; then
+        echores "no"
+        return 1
+    fi
+    if pkg_config_add "$2" ; then
+        if test $_cross_compile = no ; then
+            if cc_check && tmp_run ; then
+                echo > /dev/null # idiot NOP
+            else
+                extra_cflags="$old_extra_cflags"
+                libs_mplayer="$old_libs_mplayer"
+                echores "no - does not run"
+                return 1
+            fi
+        fi
+        lua=yes
+    fi
+    echores "$lua"
+    test "$lua" = yes
+    return $?
+}
+
+if test "$lua" = auto ; then
+
+lua=no
+test_lua 51 "lua >= 5.1.0 lua < 5.2.0"
+test_lua 51deb "lua5.1 >= 5.1.0" # debian
+test_lua luajit "luajit >= 2.0.0"
+# assume all our dependencies (libquvi in particular) link with 5.1
+test_lua 52 "lua >= 5.2.0"
+test_lua 52deb "lua5.2 >= 5.2.0" # debian
+
+fi
+
+if test "$lua" = yes ; then
+    def_lua='#define CONFIG_LUA 1'
+else
+    def_lua='#undef CONFIG_LUA'
+fi
+
 echocheck "encoding"
 if test "$_encoding" = yes ; then
     def_encoding="#define CONFIG_ENCODING 1"
@@ -3155,6 +3267,7 @@ DUMMY_OSD = $_dummy_osd
 LIBBLURAY = $_bluray
 LIBBS2B = $_libbs2b
 LCMS2 = $_lcms2
+LUA = $lua
 LIBPOSTPROC = $libpostproc
 LIBAVDEVICE = $libavdevice
 LIBAVFILTER = $libavfilter
@@ -3341,6 +3454,7 @@ $def_libquvi9
 $def_libguess
 
 $def_lcms2
+$def_lua
 
 
 /* libvo options */