This is (part of) a normative change in the ECMA-262 spec. See:
https://github.com/tc39/ecma262/commit/a9ae96e
This implements just support for resizing ArrayBuffer objects. This does
not implement the SharedArrayBuffer changes, as we do not have enough
support to do so.
This commit un-deprecates DeprecatedString, and repurposes it as a byte
string.
As the null state has already been removed, there are no other
particularly hairy blockers in repurposing this type as a byte string
(what it _really_ is).
This commit is auto-generated:
$ xs=$(ack -l \bDeprecatedString\b\|deprecated_string AK Userland \
Meta Ports Ladybird Tests Kernel)
$ perl -pie 's/\bDeprecatedString\b/ByteString/g;
s/deprecated_string/byte_string/g' $xs
$ clang-format --style=file -i \
$(git diff --name-only | grep \.cpp\|\.h)
$ gn format $(git ls-files '*.gn' '*.gni')
This patch makes IteratorRecord an Object. Although it's not exposed to
author code, this does allow us to store it in a VM register.
Now that we can store it in a VM register, we don't need to convert it
back and forth between IteratorRecord and Object when accessing it from
bytecode.
The big win here is avoiding 3 [[Get]] accesses on every iteration step
of for..of loops. There are also a bunch of smaller efficiencies gained.
20% speed-up on this microbenchmark:
function go(a) {
for (const p of a) {
}
}
const a = [];
a.length = 1_000_000;
go(a);
This ensures that repeated loads of the same module succeed. (There is a
specific criteria where the same exact module object has to be returned
for multiple loads of the same referrer + specifier.)
Note that we don't check the referrer at the moment, that's a FIXME.
In particular, this patch focuses on:
- Updating the old "import assertions" to the new "import attributes"
- Allowing realms as module import referrer
The number of registers in a call frame never changes, so we can
allocate it at the end of the CallFrame object and save ourselves the
cost of allocating separate Vector storage for every call frame.
Instead of allocating these in a mixture of ways, we now always put
them on the malloc heap, and keep an intrusive linked list of them
that we can iterate for GC marking purposes.
This required setting things up so that all function objects can plop
a PrimitiveString there instead of an AK string.
This is a step towards making ExecutionContext easier to allocate.
(Instead of MarkedVector<Value>.) This is a step towards not storing
argument lists in MarkedVector<Value> at all. Note that they still end
up in MarkedVectors since that's what ExecutionContext has.
The previous implementation was calling `backtrace()` for every
function call, which is quite slow.
Instead, this implementation provides VM::stack_trace() which unwinds
the native stack, maps it through NativeExecutable::get_source_range
and combines it with source ranges from interpreted call frames.
This commit removes DeprecatedString's "null" state, and replaces all
its users with one of the following:
- A normal, empty DeprecatedString
- Optional<DeprecatedString>
Note that null states of DeprecatedFlyString/StringView/etc are *not*
affected by this commit. However, DeprecatedString::empty() is now
considered equal to a null StringView.
Instead of trying to keep a live reference to the bytecode interpreter's
current instruction stream iterator, we now simply copy the current
iterator whenever pushing to the ExecutionContext stack.
This fixes a stack-use-after-return issue reported by ASAN.
This works by adding source start/end offset to every bytecode
instruction. In the future we can make this more efficient by keeping
a map of bytecode ranges to source ranges in the Executable instead,
but let's just get traces working first.
Co-Authored-By: Andrew Kaster <akaster@serenityos.org>
This change introduces a very basic GC graph dumper. The `dump_graph()`
function outputs JSON data that contains information about all nodes in
the graph, including their class types and edges.
Root nodes will have a property indicating their root type or source
location if the root is captured by a SafeFunction. It would be useful
to add source location for other types of roots in the future.
Output JSON dump have following format:
```json
"4908721208": {
"class_name": "Accessor",
"edges": [
"4909298232",
"4909297976"
]
},
"4907520440": {
"root": "SafeFunction Optional Optional.h:137",
"class_name": "Realm",
"edges": [
"4908269624",
"4924821560",
"4908409240",
"4908483960",
"4924527672"
]
},
"4908251320": {
"class_name": "CSSStyleRule",
"edges": [
"4908302648",
"4925101656",
"4908251192"
]
},
```
This loosens the connection to the AST interpreter and will allow us to
generate SourceRanges for the Bytecode interpreter in the future as well
Moves UnrealizedSourceRanges from TracebackFrame to the JS namespace for
this
Rather than splitting the Iterator type and its AOs into two files,
let's combine them into one file to match every other JS runtime object
that we have.
This is in preparation for an upcoming implementation of the Iterator
Helpers proposal. That proposal will require a JS::Object type named
"Iterator", so this rename is to avoid conflicts.
Instead of assuming that there's an active AST interpreter, this code
now takes VM& everywhere and invokes the appropriate interpreter.
92 new passes on test262. :^)
The JS::VM now owns the one Bytecode::Interpreter. We no longer have
multiple bytecode interpreters, and there is no concept of a "current"
bytecode interpreter.
If you ask for VM::bytecode_interpreter_if_exists(), it will return null
if we're not running the program in "bytecode enabled" mode.
If you ask for VM::bytecode_interpreter(), it will return a bytecode
interpreter in all modes. This is used for situations where even the AST
interpreter switches to bytecode mode (generators, etc.)
Don't try to implement this AO in bytecode. Instead, the bytecode
Interpreter class now has a run() API with the same inputs as the AST
interpreter. It sets up the necessary environments etc, including
invoking the GlobalDeclarationInstantiation AO.
