Commit Graph

141 Commits

Author SHA1 Message Date
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
afd980b4f6 Refactor the internals of Func to remove layers of indirection (#1363)
* Remove `WrappedCallable` indirection

At this point `Func` has evolved quite a bit since inception and the
`WrappedCallable` trait I don't believe is needed any longer. This
should help clean up a few entry points by having fewer traits in play.

* Remove the `Callable` trait

This commit removes the `wasmtime::Callable` trait, changing the
signature of `Func::new` to take an appropriately typed `Fn`.
Additionally the function now always takes `&Caller` like `Func::wrap`
optionally can, to empower `Func::new` to have the same capabilities of
`Func::wrap`.

* Add a test for an already-fixed issue

Closes #849

* rustfmt

* Update more locations for `Callable`

* rustfmt

* Remove a stray leading borrow

* Review feedback

* Remove unneeded `wasmtime_call_trampoline` shim
2020-03-19 14:21:45 -05:00
Alex Crichton
39ba281bc7 Update some documentation on Memory (#1360)
* Update some documentation on `Memory`

Merged #1357 a bit too quickly before all feedback came in!

* More words about growth
2020-03-19 09:16:40 -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
d2666b2f3b Expand Memory docs and add examples (#1357)
Try to thoroughly document unsafety of `Memory` and how it can be used
safely.

cc #1272
2020-03-18 14:39:55 -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
Alex Crichton
ba0dc40b2b Handle select relocations while generating trampolines (#1347)
* Handle select relocations while generating trampolines

Trampoline generation for all function signatures exposed a preexisting
bug in wasmtime where trampoline generation occasionally does have
relocations, but it's asserted that trampolines don't generate
relocations, causing a panic. The relocation is currently primarily the
probestack function which happens when functions might have a huge
number of parameters, but not so huge as to blow the wasmparser limit of
how many parameters are allowed.

This commit fixes the issue by handling relocations for trampolines in
the same manner as the rest of the code. Note that dynamically-generated
trampolines via the `Func` API still panic if they have too many
arguments and generate a relocation, but it seems like we can try to fix
that later if the need truly arises.

Closes #1322

* Log trampoline relocations
2020-03-17 16:30:21 -05:00
Alex Crichton
65e32b3660 Store module name on wasmtime_environ::Module (#1309)
* Store module name on `wasmtime_environ::Module`

This keeps all name information in one place so we dont' have to keep
extra structures around in `wasmtime::Module`.

* rustfmt
2020-03-13 17:51:10 -05:00
Alex Crichton
950dc2fbc6 Fill out API docs on wasmtime::Module (#1305)
* Fill out API docs on `wasmtime::Module`

Part of #1272

* Apply suggestions from code review

Co-Authored-By: Nick Fitzgerald <fitzgen@gmail.com>

Co-authored-by: Nick Fitzgerald <fitzgen@gmail.com>
2020-03-12 16:41:17 -05:00
Alex Crichton
3e2be43502 Pre-generate trampoline functions (#957)
* Refactor wasmtime_runtime::Export

Instead of an enumeration with variants that have data fields have an
enumeration where each variant has a struct, and each struct has the
data fields. This allows us to store the structs in the `wasmtime` API
and avoid lots of `panic!` calls and various extraneous matches.

* Pre-generate trampoline functions

The `wasmtime` crate supports calling arbitrary function signatures in
wasm code, and to do this it generates "trampoline functions" which have
a known ABI that then internally convert to a particular signature's ABI
and call it. These trampoline functions are currently generated
on-the-fly and are cached in the global `Store` structure. This,
however, is suboptimal for a few reasons:

* Due to how code memory is managed each trampoline resides in its own
  64kb allocation of memory. This means if you have N trampolines you're
  using N * 64kb of memory, which is quite a lot of overhead!

* Trampolines are never free'd, even if the referencing module goes
  away. This is similar to #925.

* Trampolines are a source of shared state which prevents `Store` from
  being easily thread safe.

This commit refactors how trampolines are managed inside of the
`wasmtime` crate and jit/runtime internals. All trampolines are now
allocated in the same pass of `CodeMemory` that the main module is
allocated into. A trampoline is generated per-signature in a module as
well, instead of per-function. This cache of trampolines is stored
directly inside of an `Instance`. Trampolines are stored based on
`VMSharedSignatureIndex` so they can be looked up from the internals of
the `ExportFunction` value.

The `Func` API has been updated with various bits and pieces to ensure
the right trampolines are registered in the right places. Overall this
should ensure that all trampolines necessary are generated up-front
rather than lazily. This allows us to remove the trampoline cache from
the `Compiler` type, and move one step closer to making `Compiler`
threadsafe for usage across multiple threads.

Note that as one small caveat the `Func::wrap*` family of functions
don't need to generate a trampoline at runtime, they actually generate
the trampoline at compile time which gets passed in.

Also in addition to shuffling a lot of code around this fixes one minor
bug found in `code_memory.rs`, where `self.position` was loaded before
allocation, but the allocation may push a new chunk which would cause
`self.position` to be zero instead.

* Pass the `SignatureRegistry` as an argument to where it's needed.

This avoids the need for storing it in an `Arc`.

* Ignore tramoplines for functions with lots of arguments

Co-authored-by: Dan Gohman <sunfish@mozilla.com>
2020-03-12 16:17:48 -05:00
Alex Crichton
34f768ddd5 Temporarily remove support for interface types (#1292)
* Temporarily remove support for interface types

This commit temporarily removes support for interface types from the
`wasmtime` CLI and removes the `wasmtime-interface-types` crate. An
error is now printed for any input wasm modules that have wasm interface
types sections to indicate that support has been removed and references
to two issues are printed as well:

* #677 - tracking work for re-adding interface types support
* #1271 - rationale for removal and links to other discussions

Closes #1271

* Update the python extension
2020-03-12 15:05:39 -05:00
Alex Crichton
3c51d3adb8 Move all examples to a top-level directory (#1286)
* Move all examples to a top-level directory

This commit moves all API examples (Rust and C) to a top-level
`examples` directory. This is intended to make it more discoverable and
conventional as to where examples are located. Additionally all examples
are now available in both Rust and C to see how to execute the example
in the language you're familiar with. The intention is that as more
languages are supported we'd add more languages as examples here too.

Each example is also accompanied by either a `*.wat` file which is
parsed as input, or a Rust project in a `wasm` folder which is compiled
as input.

A simple driver crate was also added to `crates/misc` which executes all
the examples on CI, ensuring the C and Rust examples all execute
successfully.
2020-03-11 15:37:24 -05:00
Alex Crichton
11510ec426 Disallow values to cross stores (#1016)
* Disallow values to cross stores

Lots of internals in the wasmtime-{jit,runtime} crates are highly
unsafe, so it's up to the `wasmtime` API crate to figure out how to make
it safe. One guarantee we need to provide is that values never cross
between stores. For example you can't take a function in one store and
move it over into a different instance in a different store. This
dynamic check can't be performed at compile time and it's up to
`wasmtime` to do the check itself.

This adds a number of checks, but not all of them, to the codebase for
now. This primarily adds checks around instantiation, globals, and
tables. The main hole in this is functions, where you can pass in
arguments or return values that are not from the right store. For now
though we can't compile modules with `anyref` parameters/returns anyway,
so we should be good. Eventually when that is supported we'll need to
put the guards in place.

Closes #958

* Clarify how values test they come from stores

* Allow null anyref to initialize tables
2020-03-10 09:28:31 -05:00
Alex Crichton
85fab0ab56 Expand Func documentation, rewrite Rust embed docs (#1236)
This commit expands the documentation of the `Func` type as well as
updating the Rust embedding tutorial with more recent APIs. I wanted to
also leave space in the Rust tutorial to get more ambitious over time
with what it's documenting, but I stopped around here, curious to see
what others think about it!
2020-03-05 12:54:42 -06:00
Maciej Woś
8acfdbdd8a add more wrappers and getters (#1222) 2020-03-03 22:58:11 -06:00
Alex Crichton
0dbfad3aa7 Fix broken API doc links (#1020)
Also enable the lint to guarantee they stay un-broken.
2020-02-28 12:44:27 -06:00
Dan Gohman
588cdd47f9 Add dependency versions and a README.md (#1004)
* Add a version to a path dependeency for publishing on crates.io.

* Add a README.md for wasmtime-profiling.

* Add versions to the wasmtime-profiling dependencies.
2020-02-26 18:13:50 -06:00
Nick Fitzgerald
ef0cabf8b4 Address review feedback 2020-02-26 14:37:28 -08:00
Nick Fitzgerald
81227892da Implement bulk memory's partial failure instantiation semantics
Essentially, table and memory out of bounds errors are no longer link errors,
but traps after linking. This means that the partail writes / inits are visible.
2020-02-26 14:35:09 -08:00
Nick Fitzgerald
cb97e4ec8e Implement table.init and elem.drop from the bulk memory proposal 2020-02-26 14:35:09 -08:00
Nick Fitzgerald
33b4a37bcb Add support for table.copy
This adds support for the `table.copy` instruction from the bulk memory
proposal. It also supports multiple tables, which were introduced by the
reference types proposal.

Part of #928
2020-02-26 14:30:43 -08:00
Nick Fitzgerald
6d01fd4103 deps: Update wat to 1.0.9 2020-02-26 14:23:33 -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
c8ab1e293e Improve robustness of cache loading/storing (#974)
* Improve robustness of cache loading/storing

Today wasmtime incorrectly loads compiled compiled modules from the
global cache when toggling settings such as optimizations. For example
if you execute `wasmtime foo.wasm` that will cache globally an
unoptimized version of the wasm module. If you then execute `wasmtime -O
foo.wasm` it would then reload the unoptimized version from cache, not
realizing the compilation settings were different, and use that instead.
This can lead to very surprising behavior naturally!

This commit updates how the cache is managed in an attempt to make it
much more robust against these sorts of issues. This takes a leaf out of
rustc's playbook and models the cache with a function that looks like:

    fn load<T: Hash>(
        &self,
        data: T,
        compute: fn(T) -> CacheEntry,
    ) -> CacheEntry;

The goal here is that it guarantees that all the `data` necessary to
`compute` the result of the cache entry is hashable and stored into the
hash key entry. This was previously open-coded and manually managed
where items were hashed explicitly, but this construction guarantees
that everything reasonable `compute` could use to compile the module is
stored in `data`, which is itself hashable.

This refactoring then resulted in a few workarounds and a few fixes,
including the original issue:

* The `Module` type was split into `Module` and `ModuleLocal` where only
  the latter is hashed. The previous hash function for a `Module` left
  out items like the `start_func` and didn't hash items like the imports
  of the module. Omitting the `start_func` was fine since compilation
  didn't actually use it, but omitting imports seemed uncomfortable
  because while compilation didn't use the import values it did use the
  *number* of imports, which seems like it should then be put into the
  cache key. The `ModuleLocal` type now derives `Hash` to guarantee that
  all of its contents affect the hash key.

* The `ModuleTranslationState` from `cranelift-wasm` doesn't implement
  `Hash` which means that we have a manual wrapper to work around that.
  This will be fixed with an upstream implementation, since this state
  affects the generated wasm code. Currently this is just a map of
  signatures, which is present in `Module` anyway, so we should be good
  for the time being.

* Hashing `dyn TargetIsa` was also added, where previously it was not
  fully hashed. Previously only the target name was used as part of the
  cache key, but crucially the flags of compilation were omitted (for
  example the optimization flags). Unfortunately the trait object itself
  is not hashable so we still have to manually write a wrapper to hash
  it, but we likely want to add upstream some utilities to hash isa
  objects into cranelift itself. For now though we can continue to add
  hashed fields as necessary.

Overall the goal here was to use the compiler to expose what we're not
hashing, and then make sure we organize data and write the right code to
ensure everything is hashed, and nothing more.

* Update crates/environ/src/module.rs

Co-Authored-By: Peter Huene <peterhuene@protonmail.com>

* Fix lightbeam

* Fix compilation of tests

* Update the expected structure of the cache

* Revert "Update the expected structure of the cache"

This reverts commit 2b53fee426a4e411c313d8c1e424841ba304a9cd.

* Separate the cache dir a bit

* Add a test the cache is busted with opt levels

* rustfmt

Co-authored-by: Peter Huene <peterhuene@protonmail.com>
2020-02-26 16:18:02 -06:00
Peter Huene
0c23c2e5e0 Merge pull request #988 from peterhuene/default-opt-level
Change default opt-level for Config to `speed`.
2020-02-26 11:03:17 -08:00
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
Peter Huene
70275a2a1d Change default opt-level for Config to speed.
This commit changes the default opt-level for a new `Config` to `speed`.

Fixes #981.
2020-02-26 09:59:45 -08:00
Dan Gohman
d55a9967b1 Remove some obsolete re-exports in wasmtime-jit. (#992)
These were from when wasmtime-jit was trying to present a different API;
now they're not needed.
2020-02-26 05:13:28 -08:00
Peter Huene
07066835db Implement PartialEq on FuncType. 2020-02-25 13:41:16 -08:00
Josh Triplett
aa78d491b0 Make Func::getN return a Result rather than an Option (#966)
This allows getN to return a detailed explanation of any type signature
mismatch, and makes it easy to just use `?` on the result of getN rather
than constructing a (necessarily vaguer) error message in the caller.
2020-02-22 17:56:23 -06:00
Josh Triplett
8be80cbd0d Extend Func::getN up to get10, allowing up to 10-argument functions (#965)
* Func: Number type arguments rather than using successive letters

This simplifies future extension, and avoids potential conflicts with
other type argument names.

* Extend Func::getN up to get10, allowing up to 10-argument functions
2020-02-22 17:09:06 -06:00
Johnnie Birch
9c6150b103 Adds perf jitdump support (#360)
Patch adds support for the perf jitdump file specification.
With this patch it should be possible to see profile data for code
generated and maped at runtime. Specifically the patch adds support
for the JIT_CODE_LOAD and the JIT_DEBUG_INFO record as described in
the specification. Dumping jitfiles is enabled with the --jitdump
flag. When the -g flag is also used there is an attempt to dump file
and line number information where this option would be most useful
when the WASM file already includes DWARF debug information.

The generation of the jitdump files has been tested on only a few wasm
files. This patch is expected to be useful/serviceable where currently
there is no means for jit profiling, but future patches may benefit
line mapping and add support for additional jitdump record types.

Usage Example:
Record
  sudo perf record -k 1 -e instructions:u target/debug/wasmtime -g
  --jitdump test.wasm
Combine
  sudo perf inject -v -j -i perf.data -o perf.jit.data
Report
  sudo perf report -i perf.jit.data -F+period,srcline
2020-02-21 08:30:21 -06:00
Alex Crichton
80b095f2e2 Add API to statically assert signature of a Func (#955)
* Add API to statically assert signature of a `Func`

This commit add a family of APIs to `Func` named `getN` where `N` is the
number of arguments. Each function will attempt to statically assert the
signature of a `Func` and, if matching, returns a corresponding closure
which can be used to invoke the underlying function.

The purpose of this commit is to add a highly optimized way to enter a
wasm module, performing type checks up front and avoiding all the costs
of boxing and unboxing arguments within a `Val`. In general this should
be much more optimized than the previous `call` API for entering a wasm
module, if the signature is statically known.

* rustfmt

* Remove stray debugging
2020-02-20 09:28:12 -06:00
Alex Crichton
4283fdc862 Fix a possible use-after-free with Global (#956)
* Fix a possible use-after-free with `Global`

This commit fixes an issue with the implementation of the
`wasmtime::Global` type where if it previously outlived the original
`Instance` it came from then you could run into a use-after-free. Now
the `Global` type holds onto its underlying `InstanceHandle` to ensure
it retains ownership of the underlying backing store of the global's
memory.

* rustfmt
2020-02-19 20:57:41 -06:00
Alex Crichton
b69a061d23 Add a test that segfault handlers ignore non-wasm segfaults (#941)
This is the subject of #940 which while fixed is good to have a
regression test for!
2020-02-18 16:22:18 -06:00
Alex Crichton
a09eed97db Update wasmparser to 0.51.2 (#952)
Fixes a bug in multi-value loop validation,
bytecodealliance/wasmparser#195
2020-02-18 13:59:22 -06:00
Alex Crichton
16affacafb Generate trampolines based on signatures (#947)
* Generate trampolines based on signatures

Instead of generating a trampoline-per-function generate a
trampoline-per-signature. This should hopefully greatly increase the
cache hit rate on trampolines within a module and avoid generating a
function-per-function.

* Update crates/runtime/src/traphandlers.rs

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

Co-authored-by: Sergei Pepyakin <s.pepyakin@gmail.com>
2020-02-18 12:32:52 -06:00
Alex Crichton
d7c9a90df9 Re-update the wat crate (#935)
This was accidentally downgraded as part of #926, but we want to be sure
to pull in wast 7.0.0!
2020-02-11 16:09:07 -08:00
Alex Crichton
ca509f8c29 Update wasmparser (#934)
Pulls in bytecodealliance/wasmparser#193 which is a good bug fix to
have!
2020-02-11 16:01:05 -08:00
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
9802005061 Remove the action and context modules from wasmtime_jit (#924)
* Remove the `action` and `context` modules from `wasmtime_jit`

These modules are now no longer necessary with the `wasmtime` crate
fleshed out, and they're entirely subsumed by the `wasmtime` API as
well.

* Remove some more modules
2020-02-07 13:22:07 -06:00
Alex Crichton
f5b505de04 Remove the jit_function_registry global state (#915)
* Remove the `jit_function_registry` global state

This commit removes on the final pieces of global state in wasmtime
today, the `jit_function_registry` module. The purpose of this module is
to help translate a native backtrace with native program counters into a
wasm backtrace with module names, function names, and wasm module
indices. To that end this module retained a global map of function
ranges to this metadata information for each compiled function.

It turns out that we already had a `NAMES` global in the `wasmtime`
crate for symbolicating backtrace addresses, so this commit moves that
global into its own file and restructures the internals to account for
program counter ranges as well. The general set of changes here are:

* Remove `jit_function_registry`
* Remove `NAMES`
* Create a new `frame_info` module which has a singleton global
  registering compiled module's frame information.
* Update traps to use the `frame_info` module to symbolicate pcs,
  directly extracting a `FrameInfo` from the module.
* Register and unregister information on a module level instead of on a
  per-function level (at least in terms of locking granluarity).

This commit leaves the new `FRAME_INFO` global variable as the only
remaining "critical" global variable in `wasmtime`, which only exists
due to the API of `Trap` where it doesn't take in any extra context when
capturing a stack trace through which we could hang off frame
information. I'm thinking though that this is ok, and we can always
tweak the API of `Trap` in the future if necessary if we truly need to
accomodate this.

* Remove a lazy_static dep

* Add some comments and restructure
2020-02-07 07:33:21 -06:00
Alex Crichton
a6adf52429 Add more CLI flags for wasm features (#917)
* Add more CLI flags for wasm features

This commit adds a few more flags to enable wasm features via the CLI,
mirroring the existing `--enable-simd` flag:

* `--enable-reference-types`
* `--enable-multi-value`
* `--enable-threads`
* `--enable-bulk-memory`

Additionally the bulk memory feature is now automatically enabled if
`reference-types` or `threads` are enabled since those two proposals
largely depend on `bulk-memory`.

* Add --enable-all to enable all wasm features

* Update src/lib.rs

Co-Authored-By: Peter Huene <peterhuene@protonmail.com>

* Apply suggestions from code review

Co-Authored-By: Peter Huene <peterhuene@protonmail.com>

Co-authored-by: Peter Huene <peterhuene@protonmail.com>
2020-02-07 04:06:59 -06:00
Alex Crichton
70345aff31 Remove all global state from the caching system (#863)
* Remove all global state from the caching system

This commit is a continuation of an effort to remove usages of
`lazy_static!` and similar global state macros which can otherwise be
accomodated with passing objects around. Previously there was a global
cache system initialized per-process, but it was initialized in a bit of
a roundabout way and wasn't actually reachable from the `wasmtime` crate
itself. The changes here remove all global state, refactor many of the
internals in the cache system, and makes configuration possible through
the `wasmtime` crate.

Specifically some changes here are:

* Usage of `lazy_static!` and many `static` items in the cache module
  have all been removed.
* Global `cache_config()`, `worker()`, and `init()` functions have all
  been removed. Instead a `CacheConfig` is a "root object" which
  internally owns its worker and passing around the `CacheConfig` is
  required for cache usage.
* The `wasmtime::Config` structure has grown options to load and parse
  cache files at runtime. Currently only loading files is supported,
  although we can likely eventually support programmatically configuring
  APIs as well.
* Usage of the `spin` crate has been removed and the dependency is removed.
* The internal `errors` field of `CacheConfig` is removed, instead
  changing all relevant methods to return a `Result<()>` instead of
  storing errors internally.
* Tests have all been updated with the new interfaces and APIs.

Functionally no real change is intended here. Usage of the `wasmtime`
CLI, for example, should still enable the cache by default.

* Fix lightbeam compilation
2020-02-06 13:11:06 -06:00
Alex Crichton
348c597a8e Remove global state for trap registration (#909)
* Remove global state for trap registration

There's a number of changes brought about in this commit, motivated by a
few things. One motivation was to remove an instance of using
`lazy_static!` in an effort to remove global state and encapsulate it
wherever possible. A second motivation came when investigating a
slowly-compiling wasm module (a bit too slowly) where a good chunk of
time was spent in managing trap registrations.

The specific change made here is that `TrapRegistry` is now stored
inside of a `Compiler` instead of inside a global. Additionally traps
are "bulk registered" for a module rather than one-by-one. This form of
bulk-registration allows optimizing the locks used here, where a lock is
only held for a module at-a-time instead of once-per-function.

With these changes the "unregister" logic has also been tweaked a bit
here and there to continue to work. As a nice side effect the `Compiler`
type now has one fewer field that requires actual mutability and has
been updated for multi-threaded compilation, nudging us closer to a
world where we can support multi-threaded compilation. Yay!

In terms of performance improvements, a local wasm test file that
previously took 3 seconds to compile is now 10% faster to compile,
taking ~2.7 seconds now.

* Perform trap resolution after unwinding

This avoids taking locks in signal handlers which feels a bit iffy...

* Remove `TrapRegistration::dummy()`

Avoid an case where you're trying to lookup trap information from a
dummy module for something that happened in a different module.

* Tweak some comments
2020-02-06 12:40:50 -06:00
Alex Crichton
9dffaf9d57 Update wasmparser dependency (#912)
* Update wasmparser dependency

Closes #905

* Fix lightbeam compilation
2020-02-06 12:25:32 -06:00
Alex Crichton
c860edc14f Disable cranelift's verifier by default (#882)
The intention of the `wasmtime` crate was to disable this verifier by
default, but it looks like cranelift actually has it turned on by
default which was making our documentation incorrect!

This was discovered by seeing a number of timeouts when fuzzing. The
debug verifier is great for fuzzing, however, so fuzzing is updated to
enable this unconditionally, meaning we'll still have timeouts. For
general users though this should make the documentation correct that the
`wasmtime` crate, by default, disables the debug verifier.
2020-02-06 19:04:53 +01:00
Alex Crichton
3dd5a3cb3f Reimplement wasmtime-wasi on top of wasmtime (#899)
* Reimplement `wasmtime-wasi` on top of `wasmtime`

This commit reimplements the `wasmtime-wasi` crate on top of the
`wasmtime` API crate, instead of being placed on top of the `wasmtime-*`
family of internal crates. The purpose here is to continue to exercise
the API as well as avoid usage of internals wherever possible and
instead use the safe API as much as possible.

The `wasmtime-wasi` crate's API has been updated as part of this PR as
well. The general outline of it is now:

* Each module snapshot has a `WasiCtxBuilder`, `WasiCtx`, and `Wasi`
  type.
  * The `WasiCtx*` types are reexported from `wasi-common`.
  * The `Wasi` type is synthesized by the `wig` crate's procedural macro
* The `Wasi` type exposes one constructor which takes a `Store` and a
  `WasiCtx`, and produces a `Wasi`
* Each `Wasi` struct fields for all the exported functions in that wasi
  module. They're all public an they all have type `wasmtime::Func`
* The `Wasi` type has a `get_export` method to fetch an struct field by
  name.

The intention here is that we can continue to make progress on #727 by
integrating WASI construction into the `Instance::new` experience, but
it requires everything to be part of the same system!

The main oddity required by the `wasmtime-wasi` crate is that it needs
access to the caller's `memory` export, if any. This is currently done
with a bit of a hack and is expected to go away once interface types are
more fully baked in.

* Remove now no-longer-necessary APIs from `wasmtime`

* rustfmt

* Rename to from_abi
2020-02-06 09:23:06 -06:00
Alex Crichton
9f76df6c85 Remove trap registration from wasmtime crate (#903)
Our trampoline shims no longer have traps baked into them so this is
largely all dead code now at this point.
2020-02-05 10:28:50 -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