This is still missing a bunch of spec steps to construct the
audio node based on the parameters of the OscillatorNode, but it is at
least enough to construct an object to be able to add a basic test which
can get built upon as more is implemented.
If a function has the following properties:
- uses only local variables and registers
- does not use `this`
- does not use `new.target`
- does not use `super`
- does not use direct eval() calls
then it is possible to entirely skip function environment allocation
because it will never be used
This change adds gathering of information whether a function needs to
access `this` from environment and updates `prepare_for_ordinary_call()`
to skip allocation when possible.
For now, this optimisation is too aggressively blocked; e.g. if `this`
is used in a function scope, then all functions in outer scopes have to
allocate an environment. It could be improved in the future, although
this implementation already allows skipping >80% of environment
allocations on Discord, GitHub and Twitter.
AK/Platform.h did not include any other header file, but expected
various macros to be defined. While many of the macros checked here are
predefined by the compiler (i.e. GCC's TARGET_OS_CPP_BUILTINS), some
may be defined by the system headers instead. In particular, so is
__GLIBC__ on glibc-based systems.
We have to include some system header for getting __GLIBC__ (or not).
It could be possible to include something relatively small and
innocuous, like <string.h> for example, but that would still clutter
the name space and make other code that would use <string.h>
functionality, but forget to include it, build on accident; we wouldn't
want that. At the end of the day, the header that actually defines
__GLIBC__ (or not) is <features.h>. It's typically included from other
glibc headers, and not by user code directly, which makes it unlikely
to mask other code accidentlly forgetting to include it, since it
wouldn't include it in the first place.
<features.h> is not defined by POSIX and could be missing on other
systems (but it seems to be present at least when using either glibc or
musl), so guard its inclusion with __has_include().
Specifically, this fixes AK/StackInfo.cpp not picking up the glibc code
path in the cross aarch64-gnu (GNU/Hurd on 64-bit ARM) Lagom build.
Which currently will always throw an exception as it is unimplemented
under the hood - but this gives all of the plumbing we need in order to
create a oscillator node as used in the reduced turnstyle testcase.
An AudioNode is the fundamental building block used in 'Audio
Contexts'. In our immediate case, the audio node we are working towards
implementing is an oscillating source node.
This does two things:
* Clear exceptions when transferring control out of a finalizer
Otherwise they would resurface at the end of the next finalizer
(see test the new test case), or at the end of a function
* Pop one scheduled jump when transferring control out of a finalizer
This removes one old FIXME
Before this change both ExecutionContext and CallFrame were created
before executing function/module/script with a couple exceptions:
- executable created for default function argument evaluation has to
run in function's execution context.
- `execute_ast_node()` where executable compiled for ASTNode has to be
executed in running execution context.
This change moves all members previously owned by CallFrame into
ExecutionContext, and makes two exceptions where an executable that does
not have a corresponding execution context saves and restores registers
before running.
Now, all execution state lives in a single entity, which makes it a bit
easier to reason about and opens opportunities for optimizations, such
as moving registers and local variables into a single array.
The ReadableStreamPipeTo AO requires reading all chunks from a stream.
There actually isn't an AO defined to do that, so the "read all bytes"
implementation was changed to provide each chunk in a vector in commit
12cfa08a09.
This change makes reading all bytes a bit more uncomfortable in normal
use cases, as we now have to manually join the vector we receive. This
can also cause churn with huge allocations.
So instead, let's just provide an ad-hoc callback to receive each chunk
as they arrive.
