This commit is a fairly large refactor, mainly because it unified the
two different ways that existed to represent references.
Now Reference values are also a kind of value.
It also implements a printer for values/references instead of copying
the implementation everywhere.
Checking for this (and get()'ing it) is always invalid, so let's just
disallow it.
This also finds two bugs where the code is checking for types that can
never actually be in the variant (which was actually a refactor
artifact).
This allows multiply different kinds of interpreters to be used by the
runtime; currently a BytecodeInterpreter and a
DebuggerBytecodeInterpreter is provided.
This should make it easier to implement multiple types of interpreters
on top of a configuration, and also give a small speed boost in not
initialising as many Stack objects.
Doing that was causing a lot of malloc/free traffic, but since there's
no need to have a stable pointer to them, we can just store them by
value.
This makes execution significantly faster :^)
This allows the JS side to access the wasm memory, assuming it's
exported by the module.
This can be used to draw stuff on the wasm side and display them from
the js side, for example :^)
Previously, the ip would not be propagated correctly, and we would
produce invalid jumps when more than one level of nesting was involved.
This makes loops work :P
This commit is a bit of a mixed bag, but most of the changes are
repetitive enough to just include in a single commit.
The following instructions remain unimplemented:
- br.table
- table.init
- table.get
- table.set
- table.copy
- table.size
- table.grow
- table.fill
- ref.null
- ref.func
- ref.is_null
- drop
- i32/i64.clz
- i32/i64.ctz
- i32/i64.popcnt
- i32/i64.rotl
- i32/i64.rotr
- X.trunc.Y
- X.trunc_sat.Y
- memory.size
- memory.grow
- memory.init
- memory.copy
- memory.fill
- elem.drop
- data.drop
As the parser now flattens out the instructions and inserts synthetic
nesting/structured instructions where needed, we can treat the whole
thing as a simple parsed bytecode stream.
This currently knows how to execute the following instructions:
- unreachable
- nop
- local.get
- local.set
- {i,f}{32,64}.const
- block
- loop
- if/else
- branch / branch_if
- i32_add
- i32_and/or/xor
- i32_ne
This also extends the 'wasm' utility to optionally execute the first
function in the module with optionally user-supplied arguments.
This adds very basic support for module instantiation/allocation, as
well as a stub for an interpreter (and executions APIs).
The 'wasm' utility is further expanded to instantiate, and attempt
executing the first non-imported function in the module.
Note that as the execution is a stub, the expected result is a zero.
Regardless, this will allow future commits to implement the JS
WebAssembly API. :^)
