All-weak tables are not being revisited after being visited during
propagation; if it gets a new metatable after that, the new metatable
may not be marked.
No thread started with pcall (instead of resume) can be closed,
because coroutine.close would not respect the expected number of
results from the protected call.
A goto cannot jump into the scope of any variable declaration,
including 'global *'. To report the error, it needs a "name" for
the scope it is entering.
New function 'resetCI' resets the CallInfo list of a thread, ensuring
a proper state when creating a new thread, closing a thread, or
closing a state, so that we can run code after that. (When closing a
thread, we need to run its __close metamethods; when closing a
state, we need to run its __close metamethods and its finalizers.)
If a metatable is a weak table, its __newindex field could be collected
by an emergency collection while being used in 'luaV_finishset'. (This
bug has similarities with bug 5.3.2-1, fixed in commit a272fa66.)
This function can be called unprotected, so it should not raise any
kind of errors. (It could raise a memory-allocation error when creating
a message).
Tests for memory-allocation errors moved from 'api.lua' to this new
file, as 'api.lua' was already too big. (Besides, these tests have
nothing to do with the API.)
Lua can easily overflow an unsigned short counting nested calls.
(The limit to this value is the maximum stack size, LUAI_MAXSTACK,
which is currently 1e6.)
Since commit f407b3c4a, it was being used for two distinct (and
incompatible) meanings:
A: Function has TBC variables (now bit CIST_TBC)
B: Interpreter is closing TBC variables (original bit CIST_CLSRET)
B implies A, but A does not imply B.
The compilation of a goto or a label just create an entry and generate
boilerplate code for the gotos. As we don't know yet whether it needs a
CLOSE, we code a jump followed by a CLOSE, which is then dead code.
When a block ends (and then we know for sure whether there are variables
that need to be closed), we check the goto's against the labels of that
block. When closing a goto against a label, if it needs a CLOSE, the
compiler swaps the order of the jump and the CLOSE, making the CLOSE
active.
Optimize this opcode for the common case. For long names or method
calls after too many constants, operation can be coded as a move
followed by 'gettable'.
Instead of using 'alimit' for keeping the size of the array and at
the same time being a hint for '#t', a table now keeps these two
values separate. The Table structure has a field 'asize' with the
size of the array, while the length hint is kept in the array itself.
That way, tables with no array part waste no space with that field.
Moreover, the space for the hint may have zero cost for small arrays,
if the array of tags plus the hint still fits in a single word.
'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.
Without this extra space, sequences of insertions/deletions (and
some other uses) can have unpexpected low performances. See the
added tests for an example, and *Mathematical Models to Analyze Lua
Hybrid Tables and Why They Need a Fix* (Martínez, Nicaud, Rotondo;
arXiv:2208.13602v2) for detais.
Array part needs 1/3 of its elements filled, instead of 1/2.
Array entries use ~1/3 the memory of hash entries, so this new rule
still ensures that array parts do not use more memory than keeping
the values in the hash, while allowing more uses of the array part,
which is more efficient than the hash.
If there are no integer keys outside the array part, there is no
reason to resize it, saving the time to count its elements. Moreover,
assignments to non-integer keys will not collapse a table created with
'table.create'.
In function 'luaK_exp2val', used to generate code for indices: Macro
'hasjumps' does not consider the case when the whole expression is a
"jump" (a test). In all other of its uses, the surrounding code ensures
that the expression cannot be VJMP.
