LUAI_MAXSTACK is limited to INT_MAX/2, so can use INT_MAX/2 to define
pseudo-indices (LUA_REGISTRYINDEX) in 'lua.h'. A change in the maximum
stack size does not need to change the Lua-C ABI.
'debug.getinfo' can return number of extra arguments added to a call by
a chain of __call metavalues. That information is being used to improve
error messages about errors in these extra arguments.
Therefore, fields ftransfer/ntransfer in lua_Debug must have type
'int'. (Maximum stack size must fit in an 'int'.) Also, this commit
adds check that maximum stack size respects size_t for size in bytes.
Avoid silent conversions from int to unsigned int when calling
'luaH_resize'; avoid silent conversions from lua_Integer to int in
'table.create'; MAXASIZE corrected for the new implementation of arrays;
'luaH_resize' checks explicitly whether new size respects MAXASIZE.
(Even constructors were bypassing that check.)
The generational mode also uses the parameters for the incremental
mode in its major collections, so it should be easy to change those
parameters without having to change the GC mode.
'lua_resetthread' is back to its original signature, to avoid
incompatibilities in the ABI between releases of the same version.
New function 'lua_closethread' added with the "correct" signature.
Closing a to-be-closed variable with 'lua_settop' is too restrictive,
as it erases all slots above the variable. Moreover, it adds side
effects to 'lua_settop', which should be a fairly basic function.
This new field gets the length of 'source' in the same structure.
Unlike the other strings in that structure, 'source' can be
relatively large, and Lua already has its length readily available.
- The warning functions get an extra parameter that tells whether
message is to be continued (instead of using end-of-lines as a signal).
- The user data for the warning function is a regular value, instead
of a writable slot inside the Lua state.
New functions to reset/kill a thread/coroutine, mainly (only?) to
close any pending to-be-closed variable. ('lua_resetthread' also
allows a thread to be reused...)
Sometimes it is useful to mark to-be-closed an index that is not
at the top of the stack (e.g., if the value to be closed came from
a function call returning multiple values).
The new syntax is <local *toclose x = f()>. The mark '*' allows other
attributes to be added later without the need of new keywords; it
also allows better error messages. The API function was also renamed
('lua_tobeclosed' -> 'lua_toclose').
Roberto I