Files
wasmtime/crates/fuzzing
Alex Crichton 63d80fc509 Remove the need to have a Store for an InstancePre (#5683)
* Remove the need to have a `Store` for an `InstancePre`

This commit relaxes a requirement of the `InstancePre` API, notably its
construction via `Linker::instantiate_pre`. Previously this function
required a `Store<T>` to be present to be able to perform type-checking
on the contents of the linker, and now this requirement has been
removed.

Items stored within a linker are either a `HostFunc`, which has type
information inside of it, or an `Extern`, which doesn't have type
information inside of it. Due to the usage of `Extern` this is why a
`Store` was required during the `InstancePre` construction process, it's
used to extract the type of an `Extern`. This commit implements a
solution where the type information of an `Extern` is stored alongside
the `Extern` itself, meaning that the `InstancePre` construction process
no longer requires a `Store<T>`.

One caveat of this implementation is that some items, such as tables and
memories, technically have a "dynamic type" where during type checking
their current size is consulted to match against the minimum size
required of an import. This no longer works when using
`Linker::instantiate_pre` as the current size used is the one when it
was inserted into the linker rather than the one available at
instantiation time. It's hoped, however, that this is a relatively
esoteric use case that doesn't impact many real-world users.

Additionally note that this is an API-breaking change. Not only is the
`Store` argument removed from `Linker::instantiate_pre`, but some other
methods such as `Linker::define` grew a `Store` argument as the type
needs to be extracted when an item is inserted into a linker.

Closes #5675

* Fix the C API

* Fix benchmark compilation

* Add C API docs

* Update crates/wasmtime/src/linker.rs

Co-authored-by: Andrew Brown <andrew.brown@intel.com>

---------

Co-authored-by: Andrew Brown <andrew.brown@intel.com>
2023-02-02 11:54:20 -06:00
..
2019-11-21 14:51:07 -08:00

Fuzzing Infrastructure for Wasmtime

This crate provides test case generators and oracles for use with fuzzing.

These generators and oracles are generally independent of the fuzzing engine that might be using them and driving the whole fuzzing process (e.g. libFuzzer or AFL). As such, this crate does not contain any actual fuzz targets itself. Those are generally just a couple lines of glue code that plug raw input from (for example) libFuzzer into a generator, and then run one or more oracles on the generated test case.

If you're looking for the actual fuzz target definitions we currently have, they live in wasmtime/fuzz/fuzz_targets/* and are driven by cargo fuzz and libFuzzer.