feat(lua/util): remove dependency on luaL_setfuncs

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>

src/bindings/lua/CMakeLists.txt

@@ -1 +1 @@
-add_library(lua name.cpp numerics.cpp)
+add_library(lua util.cpp name.cpp numerics.cpp)

src/bindings/lua/name.cpp

@@ -8,6 +8,7 @@ Author: Leonardo de Moura
 #include <lua.hpp>
 #include "util/debug.h"
 #include "util/name.h"
+#include "bindings/lua/util.h"
 
 namespace lean {
 static int name_gc(lua_State * L);
@@ -81,7 +82,7 @@ static int name_lt(lua_State * L) {
 
 void init_name(lua_State * L) {
     luaL_newmetatable(L, "name.mt");
-    luaL_setfuncs(L, name_m, 0);
+    setfuncs(L, name_m, 0);
 
     lua_pushcfunction(L, mk_name);
     lua_setglobal(L, "name");

src/bindings/lua/numerics.cpp

@@ -10,6 +10,7 @@ Author: Leonardo de Moura
 #include "util/debug.h"
 #include "util/numerics/mpz.h"
 #include "util/numerics/mpq.h"
+#include "bindings/lua/util.h"
 
 namespace lean {
 template<typename T, char const * N, char const * M>
@@ -99,7 +100,7 @@ public:
 
     static void init(lua_State * L) {
         luaL_newmetatable(L, M);
-        luaL_setfuncs(L, m, 0);
+        setfuncs(L, m, 0);
 
         lua_pushcfunction(L, mk);
         lua_setglobal(L, N);

src/bindings/lua/util.cpp

@@ -0,0 +1,25 @@
+/*
+Copyright (c) 2013 Microsoft Corporation. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+
+Author: Leonardo de Moura
+*/
+#ifdef LEAN_USE_LUA
+#include <lua.hpp>
+namespace lean {
+/**
+   \brief luaL_setfuncs replacement. The function luaL_setfuncs is only available in Lua 5.2.
+*/
+void setfuncs(lua_State * L, luaL_Reg const * l, int nup) {
+    luaL_checkstack(L, nup, "too many upvalues");
+    for (; l->name != NULL; l++) {
+        // fill the table with given functions
+        for (int i = 0; i < nup; i++) // copy upvalues to the top
+            lua_pushvalue(L, -nup);
+        lua_pushcclosure(L, l->func, nup);  // closure with those upvalues
+        lua_setfield(L, -(nup + 2), l->name);
+    }
+    lua_pop(L, nup);  // remove upvalues
+}
+}
+#endif

src/bindings/lua/util.h

@@ -0,0 +1,12 @@
+/*
+Copyright (c) 2013 Microsoft Corporation. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+
+Author: Leonardo de Moura
+*/
+#ifdef LEAN_USE_LUA
+#include <lua.hpp>
+namespace lean {
+void setfuncs(lua_State * L, luaL_Reg const * l, int nup);
+}
+#endif