Commit Graph

64 Commits

Author SHA1 Message Date
Alex Crichton
1000f21338 Update wasmparser to 0.59.0 (#2013)
This commit is intended to update wasmparser to 0.59.0. This primarily
includes bytecodealliance/wasm-tools#40 which is a large update to how
parsing and validation works. The impact on Wasmtime is pretty small at
this time, but over time I'd like to refactor the internals here to lean
more heavily on that upstream wasmparser refactoring.

For now, though, the intention is to get on the train of wasmparser's
latest `main` branch to ensure we get bug fixes and such.

As part of this update a few other crates and such were updated. This is
primarily to handle the new encoding of `ref.is_null` where the type is
not part of the instruction encoding any more.
2020-07-13 16:22:41 -05:00
Till Schneidereit
f80c2abffb Update various crates' object and wast dependencies (#1908)
This somewhat cuts down on duplicate dependencies. `wast` is used in a much older version (`11.0.0`) by `witx`, and can be updated without issues there as well, but this at least gets us from 3 copies to 2.
2020-07-01 09:11:38 -05:00
Nick Fitzgerald
e40c039e65 wasmtime: Rip out incomplete/incorrect externref "host info" support
Better to be loud that we don't support attaching arbitrary host info to
`externref`s than to limp along and pretend we do support it. Supporting it
properly won't reuse any of this code anyways.
2020-06-25 14:00:40 -07:00
Nick Fitzgerald
58bb5dd953 wasmtime: Add support for func.ref and table.grow with funcrefs
`funcref`s are implemented as `NonNull<VMCallerCheckedAnyfunc>`.

This should be more efficient than using a `VMExternRef` that points at a
`VMCallerCheckedAnyfunc` because it gets rid of an indirection, dynamic
allocation, and some reference counting.

Note that the null function reference is *NOT* a null pointer; it is a
`VMCallerCheckedAnyfunc` that has a null `func_ptr` member.

Part of #929
2020-06-24 10:08:13 -07:00
Dan Gohman
caa87048ab Wasmtime 0.18.0 and Cranelift 0.65.0. 2020-06-11 17:49:56 -07:00
Dan Gohman
a76639c6fb Wasmtime 0.17.0 and Cranelift 0.64.0. (#1805) 2020-06-02 18:51:59 -07:00
Yury Delendik
15c68f2cc1 Disconnects Store state fields from Compiler (#1761)
*  Moves CodeMemory, VMInterrupts and SignatureRegistry from Compiler
*  CompiledModule holds CodeMemory and GdbJitImageRegistration
*  Store keeps track of its JIT code
*  Makes "jit_int.rs" stuff Send+Sync
*  Adds the threads example.
2020-06-02 13:44:39 -05:00
Nick Fitzgerald
a8ee0554a9 wasmtime: Initial, partial support for externref
This is enough to get an `externref -> externref` identity function
passing.

However, `externref`s that are dropped by compiled Wasm code are (safely)
leaked. Follow up work will leverage cranelift's stack maps to resolve this
issue.
2020-06-01 15:09:51 -07:00
Leonardo Yvens
0b3b9c298e impl From<anyhow::Error> for Trap (#1753)
* From<anyhow::Error> for Trap

* Add TrapReason::Error

* wasmtime: Improve Error to Trap conversion

* Remove Trap::message
2020-05-29 15:24:12 -05:00
Nick Fitzgerald
f28b3738ee Rename anyref to externref across the board 2020-05-20 11:58:55 -07:00
Nick Fitzgerald
1a4f3fb2df Update deps and tests for anyref --> externref
* Update to using `wasmparser` 0.55.0
* Update wasmprinter to 0.2.5
* Update `wat` to 1.0.18, and `wast` to 17.0.0
2020-05-14 12:47:37 -07:00
Dan Gohman
fb0b9e3ae6 Change proc_exit to unwind the stack rather than exiting the host process. (#1646)
* Remove Cranelift's OutOfBounds trap, which is no longer used.

* Change proc_exit to unwind instead of exit the host process.

This implements the semantics in https://github.com/WebAssembly/WASI/pull/235.

Fixes #783.
Fixes #993.

* Fix exit-status tests on Windows.

* Revert the wiggle changes and re-introduce the wasi-common implementations.

* Move `wasi_proc_exit` into the wasmtime-wasi crate.

* Revert the spec_testsuite change.

* Remove the old proc_exit implementations.

* Make `TrapReason` an implementation detail.

* Allow exit status 2 on Windows too.

* Fix a documentation link.

* Really fix a documentation link.
2020-05-13 15:59:43 -07:00
Josh Triplett
08983bf39c Move crates/api to crates/wasmtime (#1693)
The `wasmtime` crate currently lives in `crates/api` for historical
reasons, because we once called it `wasmtime-api` crate. This creates a
stumbling block for new contributors.

As discussed on Zulip, rename the directory to `crates/wasmtime`.
2020-05-13 16:04:31 -05:00
Alex Crichton
57fb1c69c5 Enable the multi-value proposal by default (#1667)
This was merged into the wasm spec upstream in WebAssembly/spec#1145, so
let's follow the spec and enable it by default here as well!
2020-05-06 12:37:29 -05:00
Alex Crichton
a7d90af19d Update wasmparser and wast dependencies (#1663)
Brings in updates to SIMD spec ops renumbering.
2020-05-05 16:13:14 -05:00
Dan Gohman
864cf98c8d Update release notes, wasmtime 0.16, cranelift 0.63. 2020-04-29 17:30:25 -07:00
Dan Gohman
9364eb1d98 Refactor (#1524)
* Compute instance exports on demand.

Instead having instances eagerly compute a Vec of Externs, and bumping
the refcount for each Extern, compute Externs on demand.

This also enables `Instance::get_export` to avoid doing a linear search.

This also means that the closure returned by `get0` and friends now
holds an `InstanceHandle` to dynamically hold the instance live rather
than being scoped to a lifetime.

* Compute module imports and exports on demand too.

And compute Extern::ty on demand too.

* Add a utility function for computing an ExternType.

* Add a utility function for looking up a function's signature.

* Add a utility function for computing the ValType of a Global.

* Rename wasmtime_environ::Export to EntityIndex.

This helps differentiate it from other Export types in the tree, and
describes what it is.

* Fix a typo in a comment.

* Simplify module imports and exports.

* Make `Instance::exports` return the export names.

This significantly simplifies the public API, as it's relatively common
to need the names, and this avoids the need to do a zip with
`Module::exports`.

This also changes `ImportType` and `ExportType` to have public members
instead of private members and accessors, as I find that simplifies the
usage particularly in cases where there are temporary instances.

* Remove `Instance::module`.

This doesn't quite remove `Instance`'s `module` member, it gets a step
closer.

* Use a InstanceHandle utility function.

* Don't consume self in the `Func::get*` methods.

Instead, just create a closure containing the instance handle and the
export for them to call.

* Use `ExactSizeIterator` to avoid needing separate `num_*` methods.

* Rename `Extern::func()` etc. to `into_func()` etc.

* Revise examples to avoid using `nth`.

* Add convenience methods to instance for getting specific extern types.

* Use the convenience functions in more tests and examples.

* Avoid cloning strings for `ImportType` and `ExportType`.

* Remove more obviated clone() calls.

* Simplify `Func`'s closure state.

* Make wasmtime::Export's fields private.

This makes them more consistent with ExportType.

* Fix compilation error.

* Make a lifetime parameter explicit, and use better lifetime names.

Instead of 'me, use 'instance and 'module to make it clear what the
lifetime is.

* More lifetime cleanups.
2020-04-20 15:55:33 -05:00
Alex Crichton
59a502c8de Update the wat/wast crates (#1511)
Pulls in a fix for a fuzz bug found recently where `br_on_null` might
not resolve indices and could cause a panic.
2020-04-15 11:08:22 -05:00
Alex Crichton
63c97e365e Update some dependencies (#1496)
Update the `wast` crate to 13 and handle the new `QuoteModule` case as
well.
2020-04-10 17:11:23 -05:00
Alex Crichton
328de8bf9b Add APIs to lookup values in Linker (#1480)
* Add APIs to lookup values in `Linker`

This commit adds three new methods to `Linker` in order to inspect it
after values have been inserted:

* `Linker::iter` - iterates over all defined values
* `Linker::get` - lookup a value by its `ImportType`
* `Linker::get_by_name` - lookup values based on their name

Closes #1454

* More apis!
2020-04-07 18:16:59 -05:00
Alex Crichton
bd374fd6fc Add Wasmtime-specific C API functions to return errors (#1467)
* Add Wasmtime-specific C API functions to return errors

This commit adds new `wasmtime_*` symbols to the C API, many of which
mirror the existing counterparts in the `wasm.h` header. These APIs are
enhanced in a number of respects:

* Detailed error information is now available through a
  `wasmtime_error_t`. Currently this only exposes one function which is
  to extract a string version of the error.

* There is a distinction now between traps and errors during
  instantiation and function calling. Traps only happen if wasm traps,
  and errors can happen for things like runtime type errors when
  interacting with the API.

* APIs have improved safety with respect to embedders where the lengths
  of arrays are now taken as explicit parameters rather than assumed
  from other parameters.

* Handle trap updates

* Update C examples

* Fix memory.c compile on MSVC

* Update test assertions

* Refactor C slightly

* Bare-bones .NET update

* Remove bogus nul handling
2020-04-06 15:13:06 -05:00
Dan Gohman
fde5ddf159 Fixes for 0.15 (#1449)
* Wasmtime 0.15.0 and Cranelift 0.62.0. (#1398)

* Bump more ad-hoc versions.

* Add build.rs to wasi-common's Cargo.toml.

* Update the env var name in more places.

* Remove a redundant echo.
2020-04-03 13:13:37 -07:00
Dan Gohman
092538cc54 Test 0.14 (#1417)
* Bump Wasmtime to 0.14.0.

* Update the publish script for the wiggle crate wiggle.

* More fixes.

* Fix lightbeam depenency version.

* cargo update

* Cargo update wasi-tests too.

And add cargo update to the version-bump scripts.
2020-03-26 21:53:42 -07:00
Dan Gohman
6fa9be7767 Wasmtime 0.13.0 and Cranelift 0.61.0. (#1398)
This also updates the publishing scripts to work with newly added
and reorganized crates.
2020-03-26 13:19:02 -07:00
Alex Crichton
c241f18b81 Use Linker in *.wast testing (#1391)
* Use `Linker` in `*.wast` testing

By default `Linker` disallows shadowing previously defined items, but it
looks like the `*.wast` test suites rely on this so this commit adds a
boolean flag to `Linker` as well indicating whether duplicates are
allowed.

* Review comments

* Add a test with a number of recursive instances

* Deny warnings in doctests

* No tabs
2020-03-24 17:37:32 -05:00
Alex Crichton
3b7cb6ee64 Enable jitdump profiling support by default (#1310)
* 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!
2020-03-20 11:44:51 -05:00
Alex Crichton
f63c3c814e Add a first-class way of accessing caller's exports (#1290)
* Add a first-class way of accessing caller's exports

This commit is a continuation of #1237 and updates the API of `Func` to
allow defining host functions which have easy access to a caller's
memory in particular. The new APIs look like so:

* The `Func::wrap*` family of functions was condensed into one
  `Func::wrap` function.
* The ABI layer of conversions in `WasmTy` were removed
* An optional `Caller<'_>` argument can be at the front of all
  host-defined functions now.

The old way the wasi bindings looked up memory has been removed and is
now replaced with the `Caller` type. The `Caller` type has a
`get_export` method on it which allows looking up a caller's export by
name, allowing you to get access to the caller's memory easily, and even
during instantiation.

* Add a temporary note

* Move some docs
2020-03-18 16:57:31 -05:00
Alex Crichton
5bd03d282f Update a number of wasmtime's dependencies (#1355)
* Run `cargo update`
* Use `cargo outdated` to guide some manual version bumps
2020-03-18 14:15:33 -05:00
Nick Fitzgerald
674a6208d8 Implement data.drop and memory.init and get the rest of the bulk memory spec tests passing (#1264)
* Enable the already-passing `bulk-memoryoperations/imports.wast` test

* Implement support for the `memory.init` instruction and passive data

This adds support for passive data segments and the `memory.init` instruction
from the bulk memory operations proposal. Passive data segments are stored on
the Wasm module and then `memory.init` instructions copy their contents into
memory.

* Implement the `data.drop` instruction

This allows wasm modules to deallocate passive data segments that it doesn't
need anymore. We keep track of which segments have not been dropped on an
`Instance` and when dropping them, remove the entry from the instance's hash
map. The module always needs all of the segments for new instantiations.

* Enable final bulk memory operations spec test

This requires special casing an expected error message for an `assert_trap`,
since the expected error message contains the index of an uninitialized table
element, but our trap implementation doesn't save that diagnostic information
and shepherd it out.
2020-03-10 09:30:11 -05:00
Nick Fitzgerald
cb97e4ec8e Implement table.init and elem.drop from the bulk memory proposal 2020-02-26 14:35:09 -08:00
Alex Crichton
33a39ff4f0 Bump to 0.12.0 (#997)
* Bump to 0.12.0

* Another lockfile update
2020-02-26 16:19:12 -06:00
Alex Crichton
427fc9a732 Update the wat and wast crates (#998)
Now with support for annotations, plus a few minor bug fixes
2020-02-26 12:36:00 -06:00
Josh Triplett
48202e0c31 Update dependencies to current versions, reducing duplicate versions (#963)
* Cargo.lock: Update, to no longer use multiple versions of autocfg

* Update wasmtime-debug and wasmtime-profiling to current gimli 0.20.0

This also eliminates duplicate versions of gimli and arrayvec, and
eliminates the nodrop dependency entirely.

* Update wasmtime-profiling to goblin 0.1.3 and object 0.17.0

This also eliminates two duplicate versions of goblin, and duplicate
versions of proc-macro2, quote, syn, scroll_derive, and unicode-xid.

* Update wasmtime-profiling to current scroll 0.10.1

This eliminates duplicate versions of scroll.

* Update wasmtime-profiling to current target-lexicon 0.10.0

This eliminates duplicate versions of target-lexicon.

* Update wasmtime-interface-types to current walrus and wasm-webidl-bindings

This also eliminates the oldest of the three duplicate versions of
wasmparser.

* Update wasmtime-wast to current wast 8.0.0

This eliminates one of the duplicate versions of wast.
2020-02-22 17:10:44 -06:00
Nick Fitzgerald
2af544de8b Update to cranelift 0.58.0 and enable (but ignore) reference types and bulk memory tests (#926)
* Update cranelift to 0.58.0

* Update `wasmprinter` dep to require 0.2.1

We already had it in the lock file, but this ensures we won't ever go back down.

* Ensure that our error messages match `assert_invalid`'s

The bulk of this work was done in
https://github.com/bytecodealliance/wasmparser/pull/186 but now we can test it
at the `wasmtime` level as well.

Fixes #492

* Stop feeling guilty about not matching `assert_malformed` messages

Remove the "TODO" and stop printing warning messages. These would just be busy
work to implement, and getting all the messages the exact same relies on using
the same structure as the spec interpreter's parser, which means that where you
have a helper function and they don't, then things go wrong, and vice versa. Not
worth it.

Fixes #492

* Enable (but ignore) the reference-types proposal tests

* Match test suite directly, instead of roundabout starts/endswith

* Enable (but ignore) bulk memory operations proposal test suite
2020-02-07 16:47:55 -06:00
Alex Crichton
1bfca842b0 Support Func imports with zero shims (#839)
* Move `Func` to its own file

* Support `Func` imports with zero shims

This commit extends the `Func` type in the `wasmtime` crate with static
`wrap*` constructors. The goal of these constructors is to create a
`Func` type which has zero shims associated with it, creating as small
of a layer as possible between wasm code and calling imported Rust code.

This is achieved by creating an `extern "C"` shim function which matches
the ABI of what Cranelift will generate, and then the host function is
passed directly into an `InstanceHandle` to get called later. This also
enables enough inlining opportunities that LLVM will be able to see all
functions and inline everything to the point where your function is
called immediately from wasm, no questions asked.
2020-02-04 14:32:35 -06:00
Alex Crichton
70f179b499 Update wast to 7.0.0, fix stack overflow (#897)
This updates the `wast` dependency to include bytecodealliance/wat#48
which fixes a stack overflow for deeply recursive `*.wat` files.
2020-02-04 15:14:16 +01:00
Alex Crichton
0bee67a852 Document and update the API of the externals.rs module (#812)
* Document and update the API of the `externals.rs` module

This commit ensures that all public methods and items are documented in
the `externals.rs` module, notably all external values that can be
imported and exported in WebAssembly. Along the way this also tidies up
the API and fixes a few bugs:

* `Global::new` now returns a `Result` and fails if the provided value
  does not match the type of the global.
* `Global::set` now returns a `Result` and fails if the global is either
  immutable or the provided value doesn't match the type of the global.
* `Table::new` now fails if the provided initializer does not match the
  element type.
* `Table::get` now returns `Option<Val>` instead of implicitly returning
  null.
* `Table::set` now returns `Result<()>`, returning an error on out of
  bounds or if the input type is of the wrong type.
* `Table::grow` now returns `Result<u32>`, returning the previous number
  of table elements if succesful or an error if the maximum is reached
  or the initializer value is of the wrong type. Additionally a bug was
  fixed here where if the wrong initializer was provided the table would
  be grown still, but initialization would fail.
* `Memory::data` was renamed to `Memory::data_unchecked_mut`.
  Additionally `Memory::data_unchecked` was added. Lots of caveats were
  written down about how using the method can go wrong.
* `Memory::grow` now returns `Result<u32>`, returning an error if growth
  fails or the number of pages previous the growth if successful.

* Run rustfmt

* Fix another test

* Update crates/api/src/externals.rs

Co-Authored-By: Sergei Pepyakin <s.pepyakin@gmail.com>

Co-authored-by: Sergei Pepyakin <s.pepyakin@gmail.com>
2020-01-17 09:43:35 -06:00
Alex Crichton
e5afdd2ede Document the wasmtime::Instance APIs (#814)
* Document the `wasmtime::Instance` APIs

This documents oddities like the import list and export list and how to
match them all up. Addtionally this largely just expands all the docs
related to `Instance` to get filled out.

This also moves the `set_signal_handler` functions into
platform-specific modules in order to follow Rust idioms about how to
expose platform-specific information. Additionally the methods are
marked `unsafe` because I figure anything having to do with signal
handling is `unsafe` inherently. I don't actually know what these
functions do, so they're currently still undocumented.

* Fix build of python bindings

* Fix some rebase conflicts
2020-01-16 17:58:44 -06:00
Alex Crichton
420dcd76fd Don't require Store in Instance constructor (#810)
* Don't require `Store` in `Instance` constructor

This can be inferred from the `Module` argument. Additionally add a
`store` accessor to an `Instance` in case it's needed to instantiate
another `Module`.

cc #708

* Update more constructors

* Fix a doctest

* Don't ignore store in `wasm_instance_new`

* Run rustfmt
2020-01-13 17:50:57 -06:00
Dan Gohman
ef2177ed3a Update to the latest spec_testsuite and dependencies. (#803)
* Update to the latest spec_testsuite and dependencies.

Update to target-lexicon 0.10, cranelift 0.54, wast 0.6, faerie 0.14,
and the latest spec_testsuite.

For wast and cranelift-wasm, update the code for API changes.

* Factor out the code for matching f32, f64, and v128.

This takes the idea from #802 to split out `f32_matches`, `f64_matches`,
and `v128_matches` functions, which better factor out the matching
functionality between scalar and vector.
2020-01-10 13:57:38 -08:00
Alex Crichton
28a938a62f Remove allow(improper_ctypes) (#797)
This was a bug on nightly a month or so ago but has since been fixed!
2020-01-10 14:41:49 -06:00
Alex Crichton
90db89d327 Refactor the wasmtime-wast crate, fix an early return (#798)
This commit refactors the `wasmtime-wast` crate to internally make it a
bit more concise with less repetition. Additionally it also improves the
error messages by guaranteeing that all failed tests have context
indicating where the test was defined.

It turns out there was also a bug in the previous implementation where
an `AssertMalformed` directive with a `quote` module would accidentally
skip all further tests. This has now been fixed, and all futher tests
continued to pass except for the `simd_const.wast` test. This test has
been disabled temporarily but once the `wasmparser` and `wast` crates
are updated (being worked on independently) this should be possible to
re-enable.
2020-01-10 14:17:49 -06:00
Alex Crichton
6571fb8f4f Remove HostRef from the wasmtime public API (#788)
* Remove `HostRef` from the `wasmtime` public API

This commit removes all remaining usages of `HostRef` in the public API
of the `wasmtime` crate. This involved a number of API decisions such
as:

* None of `Func`, `Global`, `Table`, or `Memory` are wrapped in `HostRef`
* All of `Func`, `Global`, `Table`, and `Memory` implement `Clone` now.
* Methods called `type` are renamed to `ty` to avoid typing `r#type`.
* Methods requiring mutability for external items now no longer require
  mutability. The mutable reference here is sort of a lie anyway since
  the internals are aliased by the underlying module anyway. This
  affects:
  * `Table::set`
  * `Table::grow`
  * `Memory::grow`
  * `Instance::set_signal_handler`
* The `Val::FuncRef` type is now no longer automatically coerced to
  `AnyRef`. This is technically a breaking change which is pretty bad,
  but I'm hoping that we can live with this interim state while we sort
  out the `AnyRef` story in general.
* The implementation of the C API was refactored and updated in a few
  locations to account for these changes:
  * Accessing the exports of an instance are now cached to ensure we
    always hand out the same `HostRef` values.
  * `wasm_*_t` for external values no longer have internal cache,
    instead they all wrap `wasm_external_t` and have an unchecked
    accessor for the underlying variant (since the type is proof that
    it's there). This makes casting back and forth much more trivial.

This is all related to #708 and while there's still more work to be done
in terms of documentation, this is the major bulk of the rest of the
implementation work on #708 I believe.

* More API updates

* Run rustfmt

* Fix a doc test

* More test updates
2020-01-10 10:42:14 -06:00
Dan Gohman
336ee94c89 Bump version to 0.9.0 (#790) 2020-01-09 21:57:40 -08:00
Alex Crichton
1fe76ef9e3 Remove the need for HostRef<Module>
This commit continues previous work and also #708 by removing the need
to use `HostRef<Module>` in the API of the `wasmtime` crate. The API
changes performed here are:

* The `Module` type is now itself internally reference counted.
* The `Module::store` function now returns the `Store` that was used to
  create a `Module`
* Documentation for `Module` and its methods have been expanded.
2020-01-08 12:46:18 -08:00
Alex Crichton
eb1991c579 Revert "Remove the need for HostRef<Module> (#778)"
This reverts commit 7b33f1c619.

Pushed a few extra commits by accident, so reverting this.
2020-01-08 12:44:59 -08:00
Alex Crichton
7b33f1c619 Remove the need for HostRef<Module> (#778)
* Remove the need for `HostRef<Module>`

This commit continues previous work and also #708 by removing the need
to use `HostRef<Module>` in the API of the `wasmtime` crate. The API
changes performed here are:

* The `Module` type is now itself internally reference counted.
* The `Module::store` function now returns the `Store` that was used to
  create a `Module`
* Documentation for `Module` and its methods have been expanded.

* Fix compliation of test programs harness

* Fix the python extension

* Update `CodeMemory` to be `Send + Sync`

This commit updates the `CodeMemory` type in wasmtime to be both `Send`
and `Sync` by updating the implementation of `Mmap` to not store raw
pointers. This avoids the need for an `unsafe impl` and leaves the
unsafety as it is currently.

* Fix a typo
2020-01-08 14:42:37 -06:00
Alex Crichton
045d6a7310 Remove the need for HostRef<Store> (#771)
* Remove the need for `HostRef<Store>`

This commit goes through the public API of the `wasmtime` crate and
removes the need for `HostRef<Store>`, as discussed in #708. This commit
is accompanied with a few changes:

* The `Store` type now also implements `Default`, creating a new
  `Engine` with default settings and returning that.

* The `Store` type now implements `Clone`, and is documented as being a
  "cheap clone" aka being reference counted. As before there is no
  supported way to create a deep clone of a `Store`.

* All APIs take/return `&Store` or `Store` instead of `HostRef<Store>`,
  and `HostRef<T>` is left as purely a detail of the C API.

* The `global_exports` function is tagged as `#[doc(hidden)]` for now
  while we await its removal.

* The `Store` type is not yet `Send` nor `Sync` due to the usage of
  `global_exports`, but it is intended to become so eventually.

* Touch up comments on some examples

* Run rustfmt
2020-01-07 16:29:44 -06:00
Andrew Brown
dd8a1fc907 Update wast to 5.0.1 (#774) 2020-01-07 15:41:26 -06:00
Alex Crichton
9ead93684e Ensure Trap is returned for start function traps (#768)
* Ensure `Trap` is returned for start function traps

Handle another case of errors coming out of instantiation, resolve a
FIXME, and remove an unneeded dependency from the wast testsuite crate.

* Run rustfmt
2020-01-07 11:45:13 -06:00