* Upgrade to the latest versions of gimli, addr2line, object
And adapt to API changes. New gimli supports wasm dwarf, resulting in
some simplifications in the debug crate.
* upgrade gimli usage in linux-specific profiling too
* Add "continue" statement after interpreting a wasm local dwarf opcode
* Consume fuel during function execution
This commit adds codegen infrastructure necessary to instrument wasm
code to consume fuel as it executes. Currently nothing is really done
with the fuel, but that'll come in later commits.
The focus of this commit is to implement the codegen infrastructure
necessary to consume fuel and account for fuel consumed correctly.
* Periodically check remaining fuel in wasm JIT code
This commit enables wasm code to periodically check to see if fuel has
run out. When fuel runs out an intrinsic is called which can do what it
needs to do in the result of fuel running out. For now a trap is thrown
to have at least some semantics in synchronous stores, but another
planned use for this feature is for asynchronous stores to periodically
yield back to the host based on fuel running out.
Checks for remaining fuel happen in the same locations as interrupt
checks, which is to say the start of the function as well as loop
headers.
* Improve codegen by caching `*const VMInterrupts`
The location of the shared interrupt value and fuel value is through a
double-indirection on the vmctx (load through the vmctx and then load
through that pointer). The second pointer in this chain, however, never
changes, so we can alter codegen to account for this and remove some
extraneous load instructions and hopefully reduce some register
pressure even maybe.
* Add tests fuel can abort infinite loops
* More fuzzing with fuel
Use fuel to time out modules in addition to time, using fuzz input to
figure out which.
* Update docs on trapping instructions
* Fix doc links
* Fix a fuzz test
* Change setting fuel to adding fuel
* Fix a doc link
* Squelch some rustdoc warnings
The jitdump header contains a "magic" field that is defined to hold
the value 0x4A695444 as u32 in native endianness. (This allows
consumers of the file to detect the endianness of the platform
where the file was written, and apply it when reading other fields.)
However, current code always writes 0x4A695444 in little-endian
byte order, even on big-endian system. This makes consumers fail
when attempting to read files written on big-endian platforms.
Fixed by always writing the magic in native endianness.
* Enable jitdump profiling support by default
This the result of some of the investigation I was doing for #1017. I've
done a number of refactorings here which culminated in a number of
changes that all amount to what I think should result in jitdump support being
enabled by default:
* Pass in a list of finished functions instead of just a range to
ensure that we're emitting jit dump data for a specific module rather
than a whole `CodeMemory` which may have other modules.
* Define `ProfilingStrategy` in the `wasmtime` crate to have everything
locally-defined
* Add support to the C API to enable profiling
* Documentation added for profiling with jitdump to the book
* Split out supported/unsupported files in `jitdump.rs` to avoid having
lots of `#[cfg]`.
* Make dependencies optional that are only used for `jitdump`.
* Move initialization up-front to `JitDumpAgent::new()` instead of
deferring it to the first module.
* Pass around `Arc<dyn ProfilingAgent>` instead of
`Option<Arc<Mutex<Box<dyn ProfilingAgent>>>>`
The `jitdump` Cargo feature is now enabled by default which means that
our published binaries, C API artifacts, and crates will support
profiling at runtime by default. The support I don't think is fully
fleshed out and working but I think it's probably in a good enough spot
we can get users playing around with it!
