Before calling a finalizer, Lua not only checks stack limits, but
actually ensures that a minimum number of slots are already allocated
for the call. (If it cannot ensure that, it postpones the finalizer.)
That avoids finalizers not running due to memory errors that the
programmer cannot control.
The computation of a new debt could overflow when we give a too large
step to 'collectgarbage"step"' and the current debt was already
negative. This is only an issue if your platform cares for it or if you
compile Lua with an option like '-fsanitize=undefined'.
If the stack does not have some minimum available space, the GC defers
calling a finalizer until the next cycle. That avoids errors while
running a finalizer that the programmer cannot control.
Conceptually, all functions get their vararg arguments in a vararg
table. The storing of vararg arguments in the stack is always treated
as an optimization.
- New macro l_strcoll to ease changing 'strcoll' to something else.
- MAXINDEXRK==1 in 'ltests.h' is enough to run test 'code.lua'.
- Removed unused '#include' in 'lutf8lib.c'.
When calling 'luaK_storevar', the 'expdesc' for the variable must be
created before the one for the expression, to satisfy the assumptions
for register allocation. So, in a statement like 'global a = exp', where
'a' is actually '_ENV.a', this variable must be handled before the
initializing expression 'exp'.
When dumping a string, adding 2 to its size may overflow a size_t for
external strings, which may not have a header. (Adding 1 is Ok, because
all strings end with a '\0' not included in their size.) The new method
for saving NULL strings code them as a repeated string, using the
reserved index 0.
The check for limit of local variables is made after generating code to
initialize them. If there are too many local variables not initialized,
the coding of instruction OP_LOADNIL could overflow an argument.
A vararg table can be virtual. If the vararg table is used only as
a base in indexing expressions, the code does not need to create an
actual table for it. Instead, it compiles the indexing expressions
into direct accesses to the internal vararg data.
- LUAMOD_API defined as 'extern "C"' in C++.
- "ANSI C" is in fact "ISO C" (comments)
- Removed option -std from makefile in testes/libs. (Easier to change
to C++ for tests).
In C, we may have several "setjmp" nested, and the "longjmp" will go
to the one given by the corresponding "jmp_buf". In C++, a "throw"
will always go to the inner "catch". So, the "catch" must check
whether it is the recipient of the "throw" and, if not, rethrow
the exception to the outer level.
An external definition for LUA_32BITS can change the API, but libraries
check number-format compatibility when loading. So, any incompatible
modules will report a clear error.
These definitions were in luaconf.h only because the standard libraries
need them. Now that llimits.h is included by the libraries, it offers a
more private place for these definitions.
