- After converting a generic GCObject to a specific type ('gco2*'),
avoid using the original GCObject (to reduce aliasing).
- Small corrections in comments in 'lopcodes.h'
- Added tests about who calls __close metamethods
Shrink a stack only when the final stack size can be at most 2/3 the
previous size with half of its entries empty. This commit also
improves the clarity of 'luaD_growstack'.
A "with stack" implementation gains too little in performance to be
worth all the noise from C-stack overflows.
This commit is almost a sketch, to test performance. There are several
pending stuff:
- review control of C-stack overflow and error messages;
- what to do with setcstacklimit;
- review comments;
- review unroll of Lua calls.
When "undumping" a long string, the function 'loadVector' can call the
reader function, which can run the garbage collector, which can collect
the string being read. So, the string must be anchored during the call
to 'loadVector'.
This commit fixes a bug introduced in commit 9cf3299fa. TOUCHED2
objects are always black while the mutator runs, but they can become
temporarily gray inside a minor collection (e.g., if the object is a
weak table).
Tables were using this bit to indicate their array sizes were real
('isrealasize'), but this bit can be useful for tests. Instead, they
can use bit 7 of their 'flag' field for that purpose. (There are only
six fast-access metamethods.) This 'flag' field only exists in tables,
so this use does not affect other types.
OLD1 objects can be potentially anywhere in the 'allgc' list (up
to 'reallyold'), but frequently they are all after 'old1' (natural
evolution of survivals) or do not exist at all (when all objects die
young). So, instead of 'markold' starts looking for them always
from the start of 'allgc', the collector keeps an extra pointer,
'firstold1', that points to the first OLD1 object in the 'allgc' list,
or is NULL if there are no OLD1 objects in that list.
Barriers cannot be active during sweep, even in generational mode.
(Although gen. mode is not incremental, it can hit a barrier when
deleting a thread and closing its upvalues.) The colors of objects are
being changed during sweep and, therefore, cannot be trusted.
When entering a coroutine, the computation of nCcalls added 'from->nci'
to correct for preallocated CallInfos, but 'nci' includes also the
Callinfos already used.
Allow memory errors to be raised through the API (throwing the
error with the memory error message); error in external allocations
raises a memory error; memory errors in coroutines are re-raised
as memory errors.
To allow their use in memory tests, some functions in 'ltests.c'
should never allocate memory. To avoid this allocation, the
library registers the strings used for status codes, and keeps
the variable '_WARN' always defined (with false instead of nil).
In 'lundump.c', when loading the upvalues of a function, there can be
a read error if the chunk is truncated. In that case, the creation
of the error message can trigger an emergency collection while the
prototype is still anchored. So, the prototype must be GC consistent
before loading the upvales, which implies that it the 'name' fields
must be filled with NULL before the reading.
The parser were mixing compiler indices of variables with stack indices,
so that when a to-be-closed variable was used inside the scope of
compile-time constants (which may be optimized away), it might be closed
in the wrong place. (See new tests for examples.)
Besides fixing the bugs, this commit also changed comments and variable
names to avoid that kind of confusion and added tests.
(Undoing part of commit f53eabeed8.) It is better to keep this encoding
stable, so that all Lua versions can read at least the version of a
binary file.
Instead of an explicit value (field 'b'), true and false use different
tag variants. This avoids reading an extra field and results in more
direct code. (Most code that uses booleans needs to distinguish between
true and false anyway.)
The initial "\n\t" to properly indent a searcher message is being added
by 'findloader' when building the error message, instead of being
included in the original message by each searcher itself.
- Several details in 'lcode.c'
- A few more tests for code generation
- Bug in assert in 'lcode.c' ("=" x "==")
- Comments in 'lopcodes.h' and 'ltable.c'
The difference in performance between immediate operands and K operands
does not seem to justify all those extra opcodes. We only keep OP_ADDI,
due to its ubiquity and because the difference is a little more relevant.
(Later, OP_SUBI will be implemented by OP_ADDI, negating the constant.)
In arithmetic/bitwise operators, the call to metamethods is made
in a separate opcode following the main one. (The main
opcode skips this next one when the operation succeeds.) This
change reduces slightly the size of the binary and the complexity
of the arithmetic/bitwise opcodes. It also simplfies the treatment
of errors and yeld/resume in these operations, as there are much
fewer cases to consider. (Only OP_MMBIN/OP_MMBINI/OP_MMBINK,
instead of all variants of all arithmetic/bitwise operators.)
The family of opcodes OP_ADDK (arithmetic operators with K constant)
were not being handled in 'luaV_finishOp', which completes their
task after an yield.
When using warn-mode '@store', from the test library, the tests ensure
not only that the expected warnings were issued, but also that there was
no extra warnings.
The macro 'luaL_pushfail' documents all places in the standard libraries
that return nil to signal some kind of failure. It is defined as
'lua_pushnil'. The manual also got a notation (@fail) to document those
returns. The tests were changed to be agnostic regarding whether 'fail'
is 'nil' or 'false'.
Added the concept of control messages to the warning system, plus the
implementation of the controls "@on"/"@off" to turn warnings on/off.
Moreover, the warning system in the test library adds some other
controls to ease the test of warnings.
When initializing a to-be-closed variable, check whether it has a
'__close' metamethod (or is a false value) and raise an error if
if it hasn't. This produces more accurate error messages. (The
check before closing still need to be done: in the C API, the value
is not constant; and the object may lose its '__close' metamethod
during the block.)
