Move all lua related files to lua/ subfolder

Also remove the lexers sub directory from the Lua search path.
As a result we attempt to open fewer files during startup:

 $ strace -e open -o log ./vis +q config.h && wc -l log

In order to avoid having to modifiy all lexers which `require('lexer')`
we instead place a symlink in the top level directory.

 $ ./configure --disable-lua
 $ rm -rf lua

Should result in a source tree with most lua specifc functionality
removed.

1 files changed, 13 insertions, 5 deletions

diff --git a/vis-lua.c b/vis-lua.c
index b88a1d1..f3b0114 100644
--- a/vis-lua.c
+++ b/vis-lua.c
@@ -1804,10 +1804,8 @@ bool vis_lua_path_add(Vis *vis, const char *path) {
 	lua_getglobal(L, "package");
 	lua_pushstring(L, path);
 	lua_pushstring(L, "/?.lua;");
-	lua_pushstring(L, path);
-	lua_pushstring(L, "/lexers/?.lua;");
-	lua_getfield(L, -5, "path");
-	lua_concat(L, 5);
+	lua_getfield(L, -3, "path");
+	lua_concat(L, 3);
 	lua_setfield(L, -2, "path");
 	lua_pop(L, 1); /* package */
 	return true;
@@ -1888,7 +1886,17 @@ void vis_lua_init(Vis *vis) {
 	ssize_t len = readlink("/proc/self/exe", path, sizeof(path)-1);
 	if (len > 0) {
 		path[len] = '\0';
-		vis_lua_path_add(vis, dirname(path));
+		/* some idotic dirname(3) implementations return pointers to statically
+		 * allocated memory, hence we use memmove to copy it back */
+		char *dir = dirname(path);
+		if (dir) {
+			size_t len = strlen(dir)+1;
+			if (len < sizeof(path) - sizeof("/lua")) {
+				memmove(path, dir, len);
+				strcat(path, "/lua");
+				vis_lua_path_add(vis, path);
+			}
+		}
 	}
 
 	vis_lua_path_add(vis, getenv("VIS_PATH"));