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livetrax/libs/lua
Robin Gareus 520dcf8cdf rework lua-bridge C++ variable references
Since lua functions are closures, C++ methods that pass arguments by
reference cannot be used directly. The previous approach (boost::ref)
failed with clang. Assume the following:

  void foo (float&) { }
  static inline float& bar () {
    boost::reference_wrapper<float> r (42);
    return r.get ();
  }

  foo ( bar () );

With gcc, "r" goes out of scope after foo's arguments are processed
and all is well.
But with clang,  "r" already leave scope when *inlined* bar() returns.

Solution: allocate some user-data on the lua-stack to hold the reference.
There is no reference to this user-data so lua will eventually
garbage collect it.

(theoretically, creating the table which holds the return-values
could trigger an emergency garbage collection when memory is low and
free the reference just while they're being pushed to the table, then
gain FuncArgs<Params> already dereferenced them all as variable on the
C stack -- probably again compiler specific)
2016-07-18 23:52:40 +02:00
..
lua amend previous commit (forgotten checkin) 2016-07-18 13:11:18 +02:00
lua-5.3.3 update to lua-5.3.3 2016-07-18 12:28:36 +02:00
LuaBridge rework lua-bridge C++ variable references 2016-07-18 23:52:40 +02:00
MSVClua
lua.cc update to lua-5.3.3 2016-07-18 12:28:36 +02:00
luastate.cc tweak lua gc 2016-07-06 03:32:08 +02:00
wscript