Commit Graph

25 Commits

Author SHA1 Message Date
Alex Crichton
3da677796b Reword env var hint for dwarf debug info (#3081)
* Reword env var hint for dwarf debug info

Try not to declare that more information will indeed be displayed,
instead suggest that the output may improve if the env var is set since
dwarf debug info wasn't parsed.

cc bytecodealliance/wasmtime-go#90

* Fix test assertion
2021-07-15 16:33:47 -05:00
Alex Crichton
7a1b7cdf92 Implement RFC 11: Redesigning Wasmtime's APIs (#2897)
Implement Wasmtime's new API as designed by RFC 11. This is quite a large commit which has had lots of discussion externally, so for more information it's best to read the RFC thread and the PR thread.
2021-06-03 09:10:53 -05:00
Pat Hickey
0f5bdc6497 only wasi_cap_std_sync and wasi_tokio need to define WasiCtxBuilders (#2917)
* wasmtime-wasi: re-exporting this WasiCtxBuilder was shadowing the right one

wasi-common's WasiCtxBuilder is really only useful wasi_cap_std_sync and
wasi_tokio to implement their own Builder on top of.

This re-export of wasi-common's is 1. not useful and 2. shadow's the
re-export of the right one in sync::*.

* wasi-common: eliminate WasiCtxBuilder, make the builder methods on WasiCtx instead

* delete wasi-common::WasiCtxBuilder altogether

just put those methods directly on &mut WasiCtx.

As a bonus, the sync and tokio WasiCtxBuilder::build functions
are no longer fallible!

* bench fixes

* more test fixes
2021-05-21 12:59:39 -05:00
Alex Crichton
7ec073cef1 Bring back per-thread lazy initialization (#2863)
* Bring back per-thread lazy initialization

Platforms Wasmtime supports may have per-thread initialization that
needs to run before WebAssembly. For example Unix needs to setup a
sigaltstack and macOS needs to set up mach ports. In #2757 this
per-thread setup was moved out of the invocation of a wasm function,
relying on the lack of Send for Store to initialize the thread at Store
creation time and never worry about it later.

This conflicted with [wasmtime's desired multithreading
story](https://github.com/bytecodealliance/wasmtime/pull/2812) so a new
[`Store::notify_switched_thread` was
added](https://github.com/bytecodealliance/wasmtime/pull/2822) to
explicitly indicate a Store has moved to another thread (if it unsafely
did so).

It turns out though that it's not always easy to determine when a
`Store` moves to a new thread. For example the Go bindings for Wasmtime
are generally unaware when a goroutine switches OS threads. This led to
https://github.com/bytecodealliance/wasmtime-go/issues/74 where a SIGILL
was left uncaught, making it appear that traps aren't working properly.

This commit revisits the decision in #2757 and moves per-thread
initialization back into the path of calling into WebAssembly. This is
differently from before, though, where there's still only one TLS access
on the path of calling into WebAssembly, unlike before where it was a
separate access. This allows us to get the speed benefits of #2757 as
well as the flexibility benefits of not having to explicitly move a
store between threads.

With this new ability this commit deletes the recently added
`Store::notify_switched_thread` method since it's no longer necessary.

* Fix a test compiling
2021-04-28 12:08:27 -05:00
Benjamin Bouvier
ba73b458b8 Introduce a new API that allows notifying that a Store has moved to a new thread (#2822)
* Introduce a new API that allows notifying that a Store has moved to a new thread

* Add backlink to documentation, and mention the new API in the multithreading doc;
2021-04-16 11:15:35 -05:00
Benjamin Bouvier
7588565078 Tweaks some tests for Mac aarch64
- some tests don't pass because of bad interactions with the system's
libunwind; ignore them for now.
- the page size on mac aarch64 is 16K, not 4K; tweak some tests which
were expecting 4K or multiples of 4K pages to use a multiple of host page size
instead.
- a cranelift-native test needed an update for the new calling convention.
2021-04-07 14:54:50 +02:00
Chris Fallin
cb48ea406e Switch default to new x86_64 backend.
This PR switches the default backend on x86, for both the
`cranelift-codegen` crate and for Wasmtime, to the new
(`MachInst`-style, `VCode`-based) backend that has been under
development and testing for some time now.

The old backend is still available by default in builds with the
`old-x86-backend` feature, or by requesting `BackendVariant::Legacy`
from the appropriate APIs.

As part of that switch, it adds some more runtime-configurable plumbing
to the testing infrastructure so that tests can be run using the
appropriate backend. `clif-util test` is now capable of parsing a
backend selector option from filetests and instantiating the correct
backend.

CI has been updated so that the old x86 backend continues to run its
tests, just as we used to run the new x64 backend separately.

At some point, we will remove the old x86 backend entirely, once we are
satisfied that the new backend has not caused any unforeseen issues and
we do not need to revert.
2021-04-02 11:35:53 -07:00
Pat Hickey
ae4c5a9d7f fixes in tests and examples 2021-03-26 15:37:57 -07:00
Alex Crichton
2697a18d2f Redo the statically typed Func API (#2719)
* Redo the statically typed `Func` API

This commit reimplements the `Func` API with respect to statically typed
dispatch. Previously `Func` had a `getN` and `getN_async` family of
methods which were implemented for 0 to 16 parameters. The return value
of these functions was an `impl Fn(..)` closure with the appropriate
parameters and return values.

There are a number of downsides with this approach that have become
apparent over time:

* The addition of `*_async` doubled the API surface area (which is quite
  large here due to one-method-per-number-of-parameters).
* The [documentation of `Func`][old-docs] are quite verbose and feel
  "polluted" with all these getters, making it harder to understand the
  other methods that can be used to interact with a `Func`.
* These methods unconditionally pay the cost of returning an owned `impl
  Fn` with a `'static` lifetime. While cheap, this is still paying the
  cost for cloning the `Store` effectively and moving data into the
  closed-over environment.
* Storage of the return value into a struct, for example, always
  requires `Box`-ing the returned closure since it otherwise cannot be
  named.
* Recently I had the desire to implement an "unchecked" path for
  invoking wasm where you unsafely assert the type signature of a wasm
  function. Doing this with today's scheme would require doubling
  (again) the API surface area for both async and synchronous calls,
  further polluting the documentation.

The main benefit of the previous scheme is that by returning a `impl Fn`
it was quite easy and ergonomic to actually invoke the function. In
practice, though, examples would often have something akin to
`.get0::<()>()?()?` which is a lot of things to interpret all at once.
Note that `get0` means "0 parameters" yet a type parameter is passed.
There's also a double function invocation which looks like a lot of
characters all lined up in a row.

Overall, I think that the previous design is starting to show too many
cracks and deserves a rewrite. This commit is that rewrite.

The new design in this commit is to delete the `getN{,_async}` family of
functions and instead have a new API:

    impl Func {
        fn typed<P, R>(&self) -> Result<&Typed<P, R>>;
    }

    impl Typed<P, R> {
        fn call(&self, params: P) -> Result<R, Trap>;
        async fn call_async(&self, params: P) -> Result<R, Trap>;
    }

This should entirely replace the current scheme, albeit by slightly
losing ergonomics use cases. The idea behind the API is that the
existence of `Typed<P, R>` is a "proof" that the underlying function
takes `P` and returns `R`. The `Func::typed` method peforms a runtime
type-check to ensure that types all match up, and if successful you get
a `Typed` value. Otherwise an error is returned.

Once you have a `Typed` then, like `Func`, you can either `call` or
`call_async`. The difference with a `Typed`, however, is that the
params/results are statically known and hence these calls can be much
more efficient.

This is a much smaller API surface area from before and should greatly
simplify the `Func` documentation. There's still a problem where
`Func::wrapN_async` produces a lot of functions to document, but that's
now the sole offender. It's a nice benefit that the
statically-typed-async verisons are now expressed with an `async`
function rather than a function-returning-a-future which makes it both
more efficient and easier to understand.

The type `P` and `R` are intended to either be bare types (e.g. `i32`)
or tuples of any length (including 0). At this time `R` is only allowed
to be `()` or a bare `i32`-style type because multi-value is not
supported with a native ABI (yet). The `P`, however, can be any size of
tuples of parameters. This is also where some ergonomics are lost
because instead of `f(1, 2)` you now have to write `f.call((1, 2))`
(note the double-parens). Similarly `f()` becomes `f.call(())`.

Overall I feel that this is a better tradeoff than before. While not
universally better due to the loss in ergonomics I feel that this design
is much more flexible in terms of what you can do with the return value
and also understanding the API surface area (just less to take in).

[old-docs]: https://docs.rs/wasmtime/0.24.0/wasmtime/struct.Func.html#method.get0

* Rename Typed to TypedFunc

* Implement multi-value returns through `Func::typed`

* Fix examples in docs

* Fix some more errors

* More test fixes

* Rebasing and adding `get_typed_func`

* Updating tests

* Fix typo

* More doc tweaks

* Tweak visibility on `Func::invoke`

* Fix tests again
2021-03-11 14:43:34 -06:00
Peter Huene
54c07d8f16 Implement shared host functions. (#2625)
* Implement defining host functions at the Config level.

This commit introduces defining host functions at the `Config` rather than with
`Func` tied to a `Store`.

The intention here is to enable a host to define all of the functions once
with a `Config` and then use a `Linker` (or directly with
`Store::get_host_func`) to use the functions when instantiating a module.

This should help improve the performance of use cases where a `Store` is
short-lived and redefining the functions at every module instantiation is a
noticeable performance hit.

This commit adds `add_to_config` to the code generation for Wasmtime's `Wasi`
type.

The new method adds the WASI functions to the given config as host functions.

This commit adds context functions to `Store`: `get` to get a context of a
particular type and `set` to set the context on the store.

For safety, `set` cannot replace an existing context value of the same type.

`Wasi::set_context` was added to set the WASI context for a `Store` when using
`Wasi::add_to_config`.

* Add `Config::define_host_func_async`.

* Make config "async" rather than store.

This commit moves the concept of "async-ness" to `Config` rather than `Store`.

Note: this is a breaking API change for anyone that's already adopted the new
async support in Wasmtime.

Now `Config::new_async` is used to create an "async" config and any `Store`
associated with that config is inherently "async".

This is needed for async shared host functions to have some sanity check during their
execution (async host functions, like "async" `Func`, need to be called with
the "async" variants).

* Update async function tests to smoke async shared host functions.

This commit updates the async function tests to also smoke the shared host
functions, plus `Func::wrap0_async`.

This also changes the "wrap async" method names on `Config` to
`wrap$N_host_func_async` to slightly better match what is on `Func`.

* Move the instance allocator into `Engine`.

This commit moves the instantiated instance allocator from `Config` into
`Engine`.

This makes certain settings in `Config` no longer order-dependent, which is how
`Config` should ideally be.

This also removes the confusing concept of the "default" instance allocator,
instead opting to construct the on-demand instance allocator when needed.

This does alter the semantics of the instance allocator as now each `Engine`
gets its own instance allocator rather than sharing a single one between all
engines created from a configuration.

* Make `Engine::new` return `Result`.

This is a breaking API change for anyone using `Engine::new`.

As creating the pooling instance allocator may fail (likely cause is not enough
memory for the provided limits), instead of panicking when creating an
`Engine`, `Engine::new` now returns a `Result`.

* Remove `Config::new_async`.

This commit removes `Config::new_async` in favor of treating "async support" as
any other setting on `Config`.

The setting is `Config::async_support`.

* Remove order dependency when defining async host functions in `Config`.

This commit removes the order dependency where async support must be enabled on
the `Config` prior to defining async host functions.

The check is now delayed to when an `Engine` is created from the config.

* Update WASI example to use shared `Wasi::add_to_config`.

This commit updates the WASI example to use `Wasi::add_to_config`.

As only a single store and instance are used in the example, it has no semantic
difference from the previous example, but the intention is to steer users
towards defining WASI on the config and only using `Wasi::add_to_linker` when
more explicit scoping of the WASI context is required.
2021-03-11 10:14:03 -06:00
Pat Hickey
8e015ca9e7 traps needed stdio 2021-02-01 15:50:05 -08:00
Pat Hickey
8313a62e46 fix test 2021-01-29 19:54:27 -08:00
Alex Crichton
51c1d4bbd6 Provide filename/line number information in Trap (#2452)
* Provide filename/line number information in `Trap`

This commit extends the `Trap` type and `Store` to retain DWARF debug
information found in a wasm file unconditionally, if it's present. This
then enables us to print filenames and line numbers which point back to
actual source code when a trap backtrace is printed. Additionally the
`FrameInfo` type has been souped up to return filename/line number
information as well.

The implementation here is pretty simplistic currently. The meat of all
the work happens in `gimli` and `addr2line`, and otherwise wasmtime is
just schlepping around bytes of dwarf debuginfo here and there!

The general goal here is to assist with debugging when using wasmtime
because filenames and line numbers are generally orders of magnitude
better even when you already have a stack trace. Another nicety here is
that backtraces will display inlined frames (learned through debug
information), improving the experience in release mode as well.

An example of this is that with this file:

```rust
fn main() {
    panic!("hello");
}
```

we get this stack trace:

```
$ rustc foo.rs --target wasm32-wasi -g
$ cargo run foo.wasm
    Finished dev [unoptimized + debuginfo] target(s) in 0.16s
     Running `target/debug/wasmtime foo.wasm`
thread 'main' panicked at 'hello', foo.rs:2:5
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
Error: failed to run main module `foo.wasm`

Caused by:
    0: failed to invoke command default
    1: wasm trap: unreachable
       wasm backtrace:
           0: 0x6c1c - panic_abort::__rust_start_panic::abort::h2d60298621b1ccbf
                           at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/library/panic_abort/src/lib.rs:77:17
                     - __rust_start_panic
                           at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/library/panic_abort/src/lib.rs:32:5
           1: 0x68c7 - rust_panic
                           at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/library/std/src/panicking.rs:626:9
           2: 0x65a1 - std::panicking::rust_panic_with_hook::h2345fb0909b53e12
                           at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/library/std/src/panicking.rs:596:5
           3: 0x1436 - std::panicking::begin_panic::{{closure}}::h106f151a6db8c8fb
                           at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/library/std/src/panicking.rs:506:9
           4:  0xda8 - std::sys_common::backtrace::__rust_end_short_backtrace::he55aa13f22782798
                           at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/library/std/src/sys_common/backtrace.rs:153:18
           5: 0x1324 - std::panicking::begin_panic::h1727e7d1d719c76f
                           at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/library/std/src/panicking.rs:505:12
           6:  0xfde - foo::main::h2db1313a64510850
                           at /Users/acrichton/code/wasmtime/foo.rs:2:5
           7: 0x11d5 - core::ops::function::FnOnce::call_once::h20ee1cc04aeff1fc
                           at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/library/core/src/ops/function.rs:227:5
           8:  0xddf - std::sys_common::backtrace::__rust_begin_short_backtrace::h054493e41e27e69c
                           at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/library/std/src/sys_common/backtrace.rs:137:18
           9: 0x1d5a - std::rt::lang_start::{{closure}}::hd83784448d3fcb42
                           at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/library/std/src/rt.rs:66:18
          10: 0x69d8 - core::ops::function::impls::<impl core::ops::function::FnOnce<A> for &F>::call_once::h564d3dad35014917
                           at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/library/core/src/ops/function.rs:259:13
                     - std::panicking::try::do_call::hdca4832ace5a8603
                           at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/library/std/src/panicking.rs:381:40
                     - std::panicking::try::ha8624a1a6854b456
                           at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/library/std/src/panicking.rs:345:19
                     - std::panic::catch_unwind::h71421f57cf2bc688
                           at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/library/std/src/panic.rs:382:14
                     - std::rt::lang_start_internal::h260050c92cd470af
                           at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/library/std/src/rt.rs:51:25
          11: 0x1d0c - std::rt::lang_start::h0b4bcf3c5e498224
                           at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/library/std/src/rt.rs:65:5
          12:  0xffc - <unknown>!__original_main
          13:  0x393 - __muloti4
                           at /cargo/registry/src/github.com-1ecc6299db9ec823/compiler_builtins-0.1.35/src/macros.rs:269
```

This is relatively noisy by default but there's filenames and line
numbers! Additionally frame 10 can be seen to have lots of frames
inlined into it. All information is always available to the embedder but
we could try to handle the `__rust_begin_short_backtrace` and
`__rust_end_short_backtrace` markers to trim the backtrace by default as
well.

The only gotcha here is that it looks like `__muloti4` is out of place.
That's because the libc that Rust ships with doesn't have dwarf
information, although I'm not sure why we land in that function for
symbolizing it...

* Add a configuration switch for debuginfo

* Control debuginfo by default with `WASM_BACKTRACE_DETAILS`

* Try cpp_demangle on demangling as well

* Rename to WASMTIME_BACKTRACE_DETAILS
2020-12-01 16:56:23 -06:00
Yury Delendik
b2b7bc10e2 machinst aarch64: New backend unwind (#2313)
* Unwind information for aarch64 backend.
2020-11-06 08:02:45 -06:00
Alex Crichton
a277cf5ee4 Store WasmFuncType in FuncType (#2365)
This commit updates `wasmtime::FuncType` to exactly store an internal
`WasmFuncType` from the cranelift crates. This allows us to remove a
translation layer when we are given a `FuncType` and want to get an
internal cranelift type out as a result.

The other major change from this commit was changing the constructor and
accessors of `FuncType` to be iterator-based instead of exposing
implementation details.
2020-11-05 08:49:03 -06:00
Leonardo Yvens
bde9555793 Add Trap::trap_code (#2309)
* add Trap::trap_code

* Add non-exhaustive wasmtime::TrapCode

* wasmtime: Better document TrapCode

* move and refactor test
2020-10-27 16:30:45 -05:00
Yury Delendik
de4af90af6 machinst x64: New backend unwind (#2266)
Addresses unwind for experimental x64 backend. The preliminary code enables backtrace on SystemV call convension.
2020-10-23 15:19:41 -05:00
Benjamin Bouvier
79abcdb035 machinst x64: add testing to the CI; 2020-07-30 10:32:00 +02:00
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
Alex Crichton
db92dcd990 Update test ignore annotations for aarch64 (#1643)
Looks like everything is in general passing now so it's probably time to
close #1521 and all other remaining tests that are failing are
classified under new more focused issues.

Closes #1521
2020-05-01 11:24:53 -05:00
Alex Crichton
d1aa86f91a Add AArch64 tests to CI (#1526)
* Add AArch64 tests to CI

This commit enhances our CI with an AArch64 builder. Currently we have
no physical hardware to run on so for now we run all tests in an
emulator. The AArch64 build is cross-compiled from x86_64 from Linux.
Tests all happen in release mode with a recent version of QEMU (recent
version because it's so much faster, and in release mode because debug
mode tests take quite a long time in an emulator).

The goal here was not to get all tests passing on CI, but rather to get
AArch64 running on CI and get it green at the same time. To achieve that
goal many tests are now ignored on aarch64 platforms. Many tests fail
due to unimplemented functionality in the aarch64 backend (#1521), and
all wasmtime tests involving compilation are also disabled due to
panicking attempting to generate generate instruction offset information
for trap symbolication (#1523).

Despite this, though, all Cranelift tests and other wasmtime tests
should be runnin on AArch64 through QEMU with this PR. Additionally
we'll have an AArch64 binary release of Wasmtime for Linux, although it
won't be too useful just yet since it will panic on almost all wasm
modules.

* Review comments
2020-04-22 12:56:54 -05:00
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
4c82da440a Move most wasmtime tests into one test suite (#1544)
* Move most wasmtime tests into one test suite

This commit moves most wasmtime tests into a single test suite which
gets compiled into one executable instead of having lots of test
executables. The goal here is to reduce disk space on CI, and this
should be achieved by having fewer executables which means fewer copies
of `libwasmtime.rlib` linked across binaries on the system. More
importantly though this means that DWARF debug information should only
be in one executable rather than duplicated across many.

* Share more build caches

Globally set `RUSTFLAGS` to `-Dwarnings` instead of individually so all
build steps share the same value.

* Allow some dead code in cranelift-codegen

Prevents having to fix all warnings for all possible feature
combinations, only the main ones which come up.

* Update some debug file paths
2020-04-17 17:22:12 -05:00