Instead of manually specifying the types and names of imports to stub
out, `--export-noop` can be used to export stub functions for any
unresolved function import.
This makes running and debugging random wasm files much easier.
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.
This allows multiply different kinds of interpreters to be used by the
runtime; currently a BytecodeInterpreter and a
DebuggerBytecodeInterpreter is provided.
This will simply "link" any given module instances and produce a list of
external values that can be used to instantiate a module.
Note that this is extremely basic and cannot resolve circular
dependencies, and depends on the instance order.
Managing the instantiated modules becomes a pain if they're on the
stack, since an instantiated module will eventually reference itself.
To make using this simpler, just avoid copying the instance.
This fixes a FIXME and will allow linking only select modules together,
instead of linking every instantiated module into a big mess of exported
entities :P
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. :^)
It's much better to tell the user "hey, the magic numbers don't check
out" than "oh there was a problem with your input" :P
Also refactors some stuff to make it possible to efficiently use the
parser error enum without it getting in the way.
This can currently parse a really simple module.
Note that it cannot parse the DataCount section, and it's still missing
almost all of the instructions.
This commit also adds a 'wasm' test utility that tries to parse a given
webassembly binary file.
It currently does nothing but exit when the parse fails, but it's a
start :^)
