This is an editorial change in the ECMA-262 spec. See:
784fc65
Note we were already doing this for a nicer error message. This is also
what lets GetIteratorFromMethod accept the method parameter as a nonnull
pointer.
This is an editorial change in the ECMA-262 spec. See:
ff60140
In doing so, as the new name implies, callsites are updated to pass in
an IteratorRecord themselves, rather than an iterable value.
This is an editorial change in the ECMA-262 spec. See:
956e5af
This splits the GetIterator AO into two AOs, to remove some recursion
and to (soon) remove optional parameters.
This is in preparation of implementing %IteratorHelperPrototype%.return.
That will invoke GeneratorResumeAbrupt, which will execute the generator
with an abrupt completion. At that time, we must take care to close the
current inner iterator.
This is required for %IteratorHelperPrototype%.return, which needs to
operate on the internal slots of the base GeneratorObject. Doing so also
provides us with the appropriate VM to be used in invocations to the
overridden IteratorHelper::execute.
In the Iterator Helpers proposal, we must create a generator object with
additional internal slots and behavior differences.
GeneratorObject is currently implemented assuming it wraps around an
ECMAScriptFunctionObject with generated bytecode. In this proposal, we
instead have "Abstract Closure" blocks. So this marks the `execute`
method as virtual, to allow the future subclass to essentially just
invoke those closures.
We will also require mutable access to the [[GeneratorState]] internal
slot.
This optional parameter is not currently set by any caller, but will be
for the Iterator Helpers proposal. In all specs, this parameter is a
static string, so we can just use a StringView rather than allocating a
(Deprecated)String on each invocation.
This also changes this optional parameter to be passed by const-ref, as
it does not need to be copied.
The dollar sign is a special character in POSIX shells and in the Ninja
build file format. If the file name contains a `$`, something goes wrong
in the escaping/unescaping of this symbol, and CMake/GCC/Clang generate
invalid dependency files where not all instances of `$` are escaped
properly. Because of this, Ninja fails to rebuild `$262Object.cpp` if
the headers included by it have changed.
Stale `$262Object.cpp.o` files have been the cause of mysterious crashes
multiple times which only go away after doing a clean build. Let's
prevent these from happening again by removing the `$` from the
filename.
We were implicitly converting the throw completion's value into a normal
completion in `AsyncFunctionDriverWrapper::continue_async_execution`,
which meant the routine generated by `generate_await` didn't know that
the value had to be thrown when execution resumed.
Without this change, we mistakenly pass 13 tests for `Array.fromAsync`,
which we do not implement yet. But even with that "regression", we pass
17 more test262 tests in total.
If an exception was thrown while evaluating the argument of an `await`
expression, we should jump to the continuation block instead of eagerly
rejecting the caller async function.
This restores the behavior prior to the addition of the separate `Await`
instruction in d66eb4e3.
If the exception from the `try` block has already been caught by
`catch`, we need to clear the saved exception before entering `finally`
so that ContinuePendingUnwind will not re-throw it.
9 new passes on test262 :^)
CreateVariable is not needed for locals because they are not stored in
environment and created binding will not be used. Also if all variables
in loop initialization sections are local then CreateLexicalEnvironment
and LeaveLexicalEnvironment can also be ommitted.
When someone calls PrimitiveString::utf16_string() on a rope string,
we know for sure that the client wants a UTF-16 string and may not
be interested in a UTF-8 version at all.
To avoid round-tripping through UTF-8 in this scenario, callers can
now inform resolve_rope_if_needed() about their preferred encoding,
should rope resolution take place. The UTF-16 case is actually a lot
simpler than the UTF-8 case, since we can simply ask for UTF-16 data
for each fiber of the rope, and then concatenate all the fibers.
Since LibJS always uses UTF-16 for regular expression matching, this
avoids round-tripping through UTF-8 whenever the input to a regex test
is already UTF-16. :^)
The RegExpLiteral AST node already has the parsed regex::Parser::Result
so let's plumb that over to the bytecode executable instead of reparsing
the regex every time NewRegExp is executed.
~12% speed-up on language/literals/regexp/S7.8.5_A2.1_T2.js in test262.
This optimization was no longer helpful after the bug fix for missing
invalidation on global delete was introduced in 331f6a9e6, since we
now have to check bindings for presence in the global environment every
time anyway.
Since the bytecode VM now has fast GetGlobal in most cases, let's not
even worry about this and just remove the unhelpful "optimization".
In fact, removing this is actually an *optimization*, since we avoid
a redundant has_binding() check on every global variable access. :^)
Using mmap was quite punishing on inputs with lots of basic blocks,
such as test262 tests with eval() in a loop that goes 64k times..
~27% speed-up on language/literals/regexp/S7.8.5_A2.1_T2.js but
presumably everything everywhere will benefit from this. :^)
This change speeds up the process of checking variable declaration
within the scope by replacing the iteration through all declared
variables (without the ability to exit early from the loop) with hash
map lookups.
This change cuts google maps loading by 17s on my computer.
