* Derive `Copy` for `Val`
* Fix `clippy::clone_on_copy` for the whole repo
* Enforce `clippy::clone_on_copy` for the workspace
* fix some more clippy::clone_on_copy that got missed
* Complete implementation in wasmtime
* Get the impl of IntoFunc to point at the new HostContext from_closure method to tie it back to the new implementation
* A little bit of cleanup to comments and naming
* Update doc comment for Func wrap_async
* Remove the borrow checking from `wiggle` entirely
This commit is a refactoring of the `wiggle` crate which powers the
`*.witx`-based bindings generation of Wasmtime for wasip1 support.
Originally `wiggle` had a full-blown runtime borrow checker which
verified that borrows were disjoint when appropriate. In #8277 this was
removed in favor of a more coarse "either all shared or all mutable"
guarantee. It turns out that this exactly matches what the Rust type
system guarantees at compile time as well.
This commit removes all runtime borrow checking in favor of compile-time
borrow checking instead. This means that there is no longer the
possibility of a runtime error arising from borrowing errors. Current
bindings in Wasmtime needed no restructuring to work with this new API.
The source of the refactors here are all in the `wiggle` crate. Changes
include:
* The `GuestPtr` type lost its type parameter. Additionally it only
contains a `u32` pointer now instead.
* The `GuestMemory` trait is replaced with a simple `enum` of
possibilities.
* Helper methods on `GuestPtr` are all moved to `GuestMemory`.
* A number of abstractions were simplified now that borrow checking is
no longer necessary.
* Generated trait methods now all take `&mut GuestMemory<'_>` as an
argument.
These changes were then propagated to the `wasmtime-wasi` and
`wasi-common` crates in their preview0 and preview1 implementations of
WASI. All changes are just general refactors, no functional change is
intended here.
* Review comments
* Fix publishing of wiggle-macro crate
* Fix wiggle docs
This commit is a refactoring and modernization of wiggle's
`BorrowChecker` implementation. This type is quite old and predates
everything related to the component model for example. This type
additionally predates the implementation of WASI threads for Wasmtime as
well. In general, this type is old and has not been updated in a long
time.
Originally a `BorrowChecker` was intended to be a somewhat cheap method
of enabling the host to have active safe shared and mutable borrows to
guest memory. Over time though this hasn't really panned out. The WASI
threads proposal, for example, doesn't allow safe shared or mutable
borrows at all. Instead everything must be modeled as a copy in or copy
out of data. This means that all of `wasmtime-wasi` and `wasi-common`
have largely already been rewritten in such a way to minimize borrows
into linear memory.
Nowadays the only types that represent safe borrows are the `GuestSlice`
type and its equivalents (e.g. `GuestSliceMut`, `GuestStr`, etc). These
are minimally used throughout `wasi-common` and `wasmtime-wasi` and when
they are used they're typically isolated to a small region of memory.
This is all coupled with the facst that `BorrowChecker` never ended up
being optimized. It's a `Mutex<HashMap<..>>` effectively and a pretty
expensive one at that. The `Mutex` is required because `&BorrowChecker`
must both allow mutations and be `Sync`. The `HashMap` is used to
implement precise byte-level region checking to fulfill the original
design requirements of what `wiggle` was envisioned to be.
Given all that, this commit guts `BorrowChecker`'s implementation and
functionality. The type is now effectively a glorified `RefCell` for the
entire span of linear memory. Regions are no longer considered when
borrows are made and instead a shared borrow is considered as borrowing
the entirety of shared memory. This means that it's not possible to
simultaneously have a safe shared and mutable borrow, even if they're
disjoint, at the same time.
The goal of this commit is to address performance issues seen in #7973
which I've seen locally as well. The heavyweight implementation of
`BorrowChecker` isn't really buying us much nowadays, especially with
much development having since moved on to the component model. The hope
is that this much coarser way of implementing borrow checking, which
should be much more easily optimizable, is sufficient for the needs of
WASI and not a whole lot else.
* Fix rustdoc warnings on Nightly
I noticed during a failed doc build of another PR we've got a number of
warnings being emitted, so resolve all those here.
* Fix more warnings
* Fix rebase conflicts
* Update some CI dependencies
* Update to the latest nightly toolchain
* Update mdbook
* Update QEMU for cross-compiled testing
* Update `cargo nextest` for usage with MIRI
prtest:full
* Remove lots of unnecessary imports
* Downgrade qemu as 8.2.1 seems to segfault
* Remove more imports
* Remove unused winch trait method
* Fix warnings about unused trait methods
* More unused imports
* More unused imports
* Remove the `WASI` submodule
Historically the `WASI` submodule in this repository was used to pull
the sources of the `*.witx` files for preview1. This has never been used
by the `wasmtime-wasi` crate (which has its own copy in the
`crates/wasi/witx` folder) and was only ever used by `wasi-common`. This
submodule also served as a location for the `witx` crate itself.
Neither of these are really needed any more as the `*.witx` files are
unlikely to ever really change again. This commit removes the submodule
entirely, as well as the `path` dependency on `witx`, and copies the
`*.witx` files in the same manner as the `wasmtime-wasi` crate.
* Updated vet entries for witx
* Remove witx special cases in publish script
* Change how the wasi-common package is built
* Configure Rust lints at the workspace level
This commit adds necessary configuration knobs to have lints configured
at the workspace level in Wasmtime rather than the crate level. This
uses a feature of Cargo first released with 1.74.0 (last week) of the
`[workspace.lints]` table. This should help create a more consistent set
of lints applied across all crates in our workspace in addition to
possibly running select clippy lints on CI as well.
* Move `unused_extern_crates` to the workspace level
This commit configures a `deny` lint level for the
`unused_extern_crates` lint to the workspace level rather than the
previous configuration at the individual crate level.
* Move `trivial_numeric_casts` to workspace level
* Change workspace lint levels to `warn`
CI will ensure that these don't get checked into the codebase and
otherwise provide fewer speed bumps for in-process development.
* Move `unstable_features` lint to workspace level
* Move `unused_import_braces` lint to workspace level
* Start running Clippy on CI
This commit configures our CI to run `cargo clippy --workspace` for all
merged PRs. Historically this hasn't been all the feasible due to the
amount of configuration required to control the number of warnings on
CI, but with Cargo's new `[lint]` table it's possible to have a
one-liner to silence all lints from Clippy by default. This commit by
default sets the `all` lint in Clippy to `allow` to by-default disable
warnings from Clippy. The goal of this PR is to enable selective access
to Clippy lints for Wasmtime on CI.
* Selectively enable `clippy::cast_sign_loss`
This would have fixed#7558 so try to head off future issues with that
by warning against this situation in a few crates. This lint is still
quite noisy though for Cranelift for example so it's not worthwhile at
this time to enable it for the whole workspace.
* Fix CI error
prtest:full
This commit implements the `wasi_unstable` module, sometimes referred to
as "preview0", in the `wasmtime-wasi` crate. Previously this was only
implemented by the `wasi-common` crate but now this is implemented for
both meaning that the switch to preview2 won't lose this functionality.
The preview0 WITX files are vendored like the preview1 files and the
implementation of preview0 is exclusively implemented by delegating to
the preview1 implementation.
Adds methods of the shape `GeneratedStruct::offset_of_<field_name>() -> u32` to allow clients to get the
same offsets used in the generated `read` and `write` methods. I don't believe there is currently a
way to get these otherwise for applications that wish to selectively read and write to fields.
I considered a couple alternatives to this:
1. Add methods like `read_<field_name>` and `write_<field_name>`. The interface to these ends up
being awkward because the `GuestType` impls are currently for owned types, so these methods would be
forced to either take ownership of the entire struct to write one field, or else silently clone the
field.
2. Add `#[repr(C)]` to the generated struct definition so that clients could use tools like
`memoffset` to calculate the offset themselves. I didn't want to depend on the witx offsets
coinciding with `repr(C)`, though.
I extended the Wiggle `records` to exercise these new methods.
This commit refactors the `wasmtime` CLI executable to be able to
support not only compiling components but additionally executing
components. While I was doing this I've additionally added a new
`--preview2` argument to enable using the new experimental
implementation of preview1 based on preview2 type/structs. This is
off-by-default but is expected to become the default in the future.
Some notable features of this change are:
* The preview1-implemented-with-preview2 module now sports
`add_to_linker_{async,sync}` to replace the previous `add_to_linker`
which always did async.
* Some trait bounds in the preview1-implemented-with-preview2 module are
simplified.
* Some minor changes were made to `wiggle`'s macros to support a "block
on" that isn't the default wiggle dummy executor (as now we actually
do need Tokio)
* Many options related to core wasm `Linker` configuration, such as
`--default-values-unknown-imports`, are not implemented for components
at this time. When used with components these options return an error.
* Construction of WASI contexts has been refactored to pass around fewer
arguments to avoid threading through lots of values for both preview1
and preview2.
* Reading the input to the Wasmtime CLI has been updated to read the
input in the `run` subcommand before handing it off to the `wasmtime`
crate's API to enable the CLI to use the contents of what's loaded to
determine what to do next.
* Our generic `./ci/run-tests.sh` script has been updated to pass the
`--features component-model` flag to ensure that this CLI support is
tested during the normal test suite.
* The CLI support for `wasi-nn` supports components as well as core wasm
modules.
* Remove deny.toml exception for wasm-coredump-builder
This isn't used any more so no need to continue to list this.
* Update Wasmtime's pretty_env_logger dependency
This removes a `deny.toml` exception for that crate, but `openvino-sys`
still depends on `pretty_env_logger 0.4.0` so a new exception is added
for that.
* Update criterion and clap dependencies
This commit started out by updating the `criterion` dependency to remove
an entry in `deny.toml`, but that ended up transitively requiring a
`clap` dependency upgrade from 3.x to 4.x because `criterion` uses
pieces of clap 4.x. Most of this commit is then dedicated to updating
clap 3.x to 4.x which was relatively simple, mostly renaming attributes
here and there.
* Update gimli-related dependencies
I originally wanted to remove the `indexmap` clause in `deny.toml` but
enough dependencies haven't updated from 1.9 to 2.0 that it wasn't
possible. In the meantime though this updates some various dependencies
to bring them to the latest and a few of them now use `indexmap` 2.0.
* Update deps to remove `windows-sys 0.45.0`
This involved updating tokio/mio and then providing new audits for new
crates. The tokio exemption was updated from its old version to the new
version and tokio remains un-audited.
* Update `syn` to 2.x.x
This required a bit of rewriting for the component-macro related bits
but otherwise was pretty straightforward. The `syn` 1.x.x track is still
present in the wasi-crypto tree at this time.
I've additionally added some trusted audits for my own publications of
`wasm-bindgen`
* Update bitflags to 2.x.x
This updates Wasmtime's dependency on the `bitflags` crate to the 2.x.x
track to keep it up-to-date.
* Update the cap-std family of crates
This bumps them all to the next major version to keep up with updates.
I've additionally added trusted entries for publishes of cap-std crates
from Dan.
There's still lingering references to rustix 0.37.x which will need to
get weeded out over time.
* Update memoffset dependency to latest
Avoids having two versions in our crate graph.
* Fix tests
* Update try_from for wiggle flags
* Fix build on AArch64 Linux
* Enable `event` for rustix on Windows too
This commit goes through all proc-macros we have in this repository and
ensures that they're all flagged with `test = false` and `doctest =
false`. This comes about as I was curious why CI time was 40m which felt
a little long and upon inspection the cross-compiled builders were
taking upwards of 30 minutes just to build everything (not including
running tests) where the non-cross-compiled builders took only about
10-15 minutes to build everything.
Further investigation into this discrepancy showed that a lot of crates
are being double-compiled in a cross-compiled situation. This is
expected at a base level and something Cargo transparently handles, for
example if a build script and the final binary need the same dependency
then it's gotta get compiled twice. What was odd is that large portions
of the Wasmtime crate graph were being compiled more than they should
be.
I tracked this down to some `dev-dependencies` for procedural macros
pointing at wasmtime crates. This makes sense for the `tests/*.rs`-style
tests which are always compiled for the target, but tests for the
proc-macro itself would be compiled for the host. By disabling tests and
doctests for the proc macro itself this removes the need for the
host-compiled version of these dependencies.
Overall this reduces a full compile of all tests from ~840 units of work
to 700 units of work according to Cargo. The set of extra crates
compiled in a cross-compiled workflow is not much smaller than in a
non-cross-compiled workflow and they all generally "make sense" as core
shared dependencies which are rooted in both Wasmtime and some
proc-macro's dependency tree, for example.
This commit updates the "integrating with Wasmtime" link in
crates/wiggle/README.md which currently results in a 404 Not Found.
I hope the link in this commit is correct, but if not hopefully someone
will point out the correct page this link should point to if this is not
the case.
Signed-off-by: Daniel Bevenius <daniel.bevenius@gmail.com>
* Remove lingering references to `experimental_x64`
This hasn't been experimental for quite a long time now and these are
all mostly old vestiges of when the current backend was under
development, so remove them all as they're no longer necessary.
* Try to fix test
* Try again to fix tests
Several of these badges were out of date, with some crates in wide production
use marked as "experimental". Insted of trying to keep them up to date, just
remove them, since they are [no longer displayed on crates.io].
[no longer displayed on crates.io]: https://doc.rust-lang.org/cargo/reference/manifest.html#the-badges-section
* wiggle: Inline some trivial functions
This commit marks a number of functions in wiggle as `#[inline]` as
they're otherwise trivial, mostly returning constants. This comes out of
some work I looked at recently with Andrew where some of these functions
showed up in profiles when they shouldn't.
* wiggle: Optimize the `GuestMemory` for shared memory
This commit implements a minor optimization to the `GuestMemory`
implementation for Wasmtime to skip most methods if a shared memory is
in play. Shared memories never get borrowed and this can be used to
internally skip some borrow-checker methods.
* wiggle: Optimize `GuestPtr::to_vec`
This commit replaces the safe implementation of `GuestPtr::to_vec` with
an unsafe implementation. The purpose of this is to speed up the
function when used with shared memory which otherwise performs a bunch
of atomic reads for types like `u8` which does validation-per-element
and isn't vectorizable. On a benchmark I was helping Andrew with this
sped up the host code enough to the point that guest code dwarfed the
execution time.
* Fix build
* wiggle: copy guest strings from shared memory
Along the same lines as #5471, this change adds a new smart pointer,
`GuestStrCow`, to copy the string bytes over from Wasm memory to the
host when the string is found in shared memory. This is necessary to
maintain Rust guarantees: with shared memory, the bytes backing a
`GuestStr` could be altered by another thread and this would invalidate
the assumption that we can dereference at any point to `&str`.
`GuestStrCow` is essentially a wrapper around `GuestStr` when the memory
is not shared but copies the memory region into a `String` when the
memory is shared.
This change updates the uses of Wiggle strings in both wasi-common and
wasi-crypto.
* review: perform UTF-8 check on `GuestStr` construction
This change upgrades `UnsafeGuestSlice` in Wiggle to expose more
functionality to be able to use `std::ptr::copy` for writing bytes into
Wasm shared memory. Additionally, it adds a new `GuestCow` type for
delineating between Wasm memory regions that can be borrowed (non-shared
memory) or must be copied (shared memory) in order to maintain Rust
guarantees.
With these in place, it is now possible to implement the `preview1`
"read" functions for shared memory. Previously, these would panic if
attempting to copy to a shared memory. This change removes the panic and
introduces some (rather complex) logic for handling both the shared and
non-shared cases:
- if reading into a Wasm non-shared memory, Wiggle guarantees that no
other guest pointers will touch the memory region and, in the absence
of concurrency, a WASI function can write directly to this memory
- if reading into a Wasm shared memory, the memory region can be
concurrently modified. At @alexcrichton's request re: Rust safety,
this change copies all of the bytes into an intermediate buffer before
using `std::ptr::copy` to move them into Wasm memory.
This change only applies to the `preview0` and `preview1`
implementations of `wasi-common`. Fixing up other WASI implementations
(esp. wasi-crypto) is left for later.
Previously, all Wiggle-generated traits were generated with `&mut self`
signatures. With the addition of the `mutable` configuration option to
`from_witx!` and `wasmtime_integration!`, one can disable this, emitting
instead traits that use `&self` (i.e., `mutable: false`). This change is
helpful for implementing wasi-threads: WASI implementations with
interior mutability will now be able to communitcate this to their
Wiggle-generated code.
The other side of this change is the `get_cx` closure passed to Wiggle's
generated `add_to_linker` function. When `mutability` is set to `true`
(default), the `get_cx` function takes a `&mut` data structure from the
store and returns a corresponding `&mut` reference, usually to a field
of the passed-in structure. When `mutability: false`, the `get_cx`
closure will still take a `&mut` data structure but now will return a
`&` reference.
* Import Wasmtime support from the `wit-bindgen` repo
This commit imports the `wit-bindgen-gen-host-wasmtime-rust` crate from
the `wit-bindgen` repository into the upstream Wasmtime repository. I've
chosen to not import the full history here since the crate is relatively
small and doesn't have a ton of complexity. While the history of the
crate is quite long the current iteration of the crate's history is
relatively short so there's not a ton of import there anyway. The
thinking is that this can now continue to evolve in-tree.
* Refactor `wasmtime-component-macro` a bit
Make room for a `wit_bindgen` macro to slot in.
* Add initial support for a `bindgen` macro
* Add tests for `wasmtime::component::bindgen!`
* Improve error forgetting `async` feature
* Add end-to-end tests for bindgen
* Add an audit of `unicase`
* Add a license to the test-helpers crate
* Add vet entry for `pulldown-cmark`
* Update publish script with new crate
* Try to fix publish script
* Update audits
* Update lock file
* Add release notes for 3.0.1
* Update some version directives for crates in Wasmtime
* Mark anything with `publish = false` as version 0.0.0
* Mark the icache coherence crate with the same version as Wasmtime
* Fix manifest directives
* Add a new "trappable" mode for wiggle to make an error type
start refactoring how errors are generated and configured
put a pin in this - you can now configure a generated error
but i need to go fix Names
Names is no longer a struct, rt is hardcoded to wiggle
rest of fixes to pass tests
its called a trappable error now
don't generate UserErrorConversion trait if empty
mention in macro docs
* undo omitting the user error conversion trait when empty
`wiggle` looks for an exported `Memory` named `"memory"` to use for its
guest slices. This change allows it to use a `SharedMemory` if this is
the kind of memory used for the export.
It is `unsafe` to use shared memory in Wiggle because of broken Rust
guarantees: previously, Wiggle could hand out slices to WebAssembly
linear memory that could be concurrently modified by some other thread.
With the introduction of Wiggle's new `UnsafeGuestSlice` (#5225, #5229,
#5264), Wiggle should now correctly communicate its guarantees through
its API.
This commit refactors the internals of `wiggle` to have fewer raw pointers and more liberally use `&[UnsafeCell<_>]`. The purpose of this refactoring is to more strictly thread through lifetime information throughout the crate to avoid getting it wrong. Additionally storing `UnsafeCell<T>` at rest pushes the unsafety of access to the leaves of modifications where Rust safety guarantees are upheld. Finally this provides what I believe is a safer internal representation of `WasmtimeGuestMemory` since it technically holds onto `&mut [u8]` un-soundly as other `&mut T` pointers are handed out.
Additionally generated `GuestTypeTransparent` impls in the `wiggle` macro were removed because they are not safe for shared memories as-is and otherwise aren't needed for WASI today. The trait has been updated to indicate that all bit patterns must be valid in addition to having the same representation on the host as in the guest to accomodate this.
* wiggle: adapt Wiggle strings for shared use
This is an extension of #5229 for the `&str` and `&mut str` types. As
documented there, we are attempting to maintain Rust guarantees for
slices that Wiggle hands out in the presence of WebAssembly shared
memory, in which case multiple threads could be modifying the underlying
data of the slice.
This change changes the API of `GuestPtr` to return an `Option` which is
`None` when attempting to view the WebAssembly data as a string and the
underlying WebAssembly memory is shared. This reuses the
`UnsafeGuestSlice` structure from #5229 to do so and appropriately marks
the region as borrowed in Wiggle's manual borrow checker. Each original
call site in this project's WASI implementations is fixed up to `expect`
that a non-shared memory is used. (Note that I can find no uses of
`GuestStrMut` in the WASI implementations).
* wiggle: make `GuestStr*` containers wrappers of `GuestSlice*`
This change makes it possible to reuse the underlying logic in
`UnsafeGuestSlice` and the `GuestSlice*` implementations to continue to
expose the `GuestStr` and `GuestStrMut` types. These types now are
simple wrappers of their `GuestSlice*` variant. The UTF-8 validation
that distinguished `GuestStr*` now lives in the `TryFrom`
implementations for each type.
* wiggle: adapt Wiggle guest slices for `unsafe` shared use
When multiple threads can concurrently modify a WebAssembly shared
memory, the underlying data for a Wiggle `GuestSlice` and
`GuestSliceMut` could change due to access from other threads. This
breaks Rust guarantees when `&[T]` and `&mut [T]` slices are handed out.
This change modifies `GuestPtr` to make `as_slice` and `as_slice_mut`
return an `Option` which is `None` when the underlying WebAssembly
memory is shared.
But WASI implementations still need access to the underlying WebAssembly
memory, both to read to it and write from it. This change adds new APIs:
- `GuestPtr::to_vec` copies the bytes from WebAssembly memory (from
which we can safely take a `&[T]`)
- `GuestPtr::as_unsafe_slice_mut` returns a wrapper `struct` from which
we can `unsafe`-ly return a mutable slice (users must accept the
unsafety of concurrently modifying a `&mut [T]`)
This approach allows us to maintain Wiggle's borrow-checking
infrastructure, which enforces the guarantee that Wiggle will not modify
overlapping regions, e.g. This is important because the underlying
system calls may expect this. Though other threads may modify the same
underlying region, this is impossible to prevent; at least Wiggle will
not be able to do so.
Finally, the changes to Wiggle's API are propagated to all WASI
implementations in Wasmtime. For now, code locations that attempt to get
a guest slice will panic if the underlying memory is shared. Note that
Wiggle is not enabled for shared memory (that will come later in
something like #5054), but when it is, these panics will be clear
indicators of locations that must be re-implemented in a thread-safe
way.
* review: remove double cast
* review: refactor to include more logic in 'UnsafeGuestSlice'
* review: add reference to #4203
* review: link all thread-safe WASI fixups to #5235
* fix: consume 'UnsafeGuestSlice' during conversion to safe versions
* review: remove 'as_slice' and 'as_slice_mut'
* review: use 'as_unsafe_slice_mut' in 'to_vec'
* review: add `UnsafeBorrowResult`
This change is the first in a series of changes to support shared memory
in Wiggle. Since Wiggle was written under the assumption of
single-threaded guest-side access, this change introduces a `shared`
field to guest memories in order to flag when this assumption will not
be the case. This change always sets `shared` to `false`; once a few
more pieces are in place, `shared` will be set dynamically when a shared
memory is detected, e.g., in a change like #5054.
Using the `shared` field, we can now decide to load Wiggle values
differently under the new assumptions. This change makes the guest
`T::read` and `T::write` calls into `Relaxed` atomic loads and stores in
order to maintain WebAssembly's expected memory consistency guarantees.
We choose Rust's `Relaxed` here to match the `Unordered` memory
consistency described in the [memory model] section of the ECMA spec.
These relaxed accesses are done unconditionally, since we theorize that
the performance benefit of an additional branch vs a relaxed load is
not much.
[memory model]: https://tc39.es/ecma262/multipage/memory-model.html#sec-memory-model
Since 128-bit scalar types do not have `Atomic*` equivalents, we remove
their `T::read` and `T::write` implementations here. They are unused by
any WASI implementations in the project.
* wiggle: fix compilation with async functions when tracing is off
Fixes#5202
* switch tracing config from a boolean to a struct
This will enable more complex tracing rules in the future
* rename AsyncConfField to FunctionField
It is going to be reused for cases other than just async functions
* add support for disabling tracing per-function
This adds a `disable_for` syntax after the `tracing` boolean. For
example:
```
wiggle::from_witx!(
tracing: true disable_for {
module1::foo,
module2::{bar, baz},
}
)
```
* Return `anyhow::Error` from host functions instead of `Trap`
This commit refactors how errors are modeled when returned from host
functions and additionally refactors how custom errors work with `Trap`.
At a high level functions in Wasmtime that previously worked with
`Result<T, Trap>` now work with `Result<T>` instead where the error is
`anyhow::Error`. This includes functions such as:
* Host-defined functions in a `Linker<T>`
* `TypedFunc::call`
* Host-related callbacks like call hooks
Errors are now modeled primarily as `anyhow::Error` throughout Wasmtime.
This subsequently removes the need for `Trap` to have the ability to
represent all host-defined errors as it previously did. Consequently the
`From` implementations for any error into a `Trap` have been removed
here and the only embedder-defined way to create a `Trap` is to use
`Trap::new` with a custom string.
After this commit the distinction between a `Trap` and a host error is
the wasm backtrace that it contains. Previously all errors in host
functions would flow through a `Trap` and get a wasm backtrace attached
to them, but now this only happens if a `Trap` itself is created meaning
that arbitrary host-defined errors flowing from a host import to the
other side won't get backtraces attached. Some internals of Wasmtime
itself were updated or preserved to use `Trap::new` to capture a
backtrace where it seemed useful, such as when fuel runs out.
The main motivation for this commit is that it now enables hosts to
thread a concrete error type from a host function all the way through to
where a wasm function was invoked. Previously this could not be done
since the host error was wrapped in a `Trap` that didn't provide the
ability to get at the internals.
A consequence of this commit is that when a host error is returned that
isn't a `Trap` we'll capture a backtrace and then won't have a `Trap` to
attach it to. To avoid losing the contextual information this commit
uses the `Error::context` method to attach the backtrace as contextual
information to ensure that the backtrace is itself not lost.
This is a breaking change for likely all users of Wasmtime, but it's
hoped to be a relatively minor change to workaround. Most use cases can
likely change `-> Result<T, Trap>` to `-> Result<T>` and otherwise
explicit creation of a `Trap` is largely no longer necessary.
* Fix some doc links
* add some tests and make a backtrace type public (#55)
* Trap: avoid a trailing newline in the Display impl
which in turn ends up with three newlines between the end of the
backtrace and the `Caused by` in the anyhow Debug impl
* make BacktraceContext pub, and add tests showing downcasting behavior of anyhow::Error to traps or backtraces
* Remove now-unnecesary `Trap` downcasts in `Linker::module`
* Fix test output expectations
* Remove `Trap::i32_exit`
This commit removes special-handling in the `wasmtime::Trap` type for
the i32 exit code required by WASI. This is now instead modeled as a
specific `I32Exit` error type in the `wasmtime-wasi` crate which is
returned by the `proc_exit` hostcall. Embedders which previously tested
for i32 exits now downcast to the `I32Exit` value.
* Remove the `Trap::new` constructor
This commit removes the ability to create a trap with an arbitrary error
message. The purpose of this commit is to continue the prior trend of
leaning into the `anyhow::Error` type instead of trying to recreate it
with `Trap`. A subsequent simplification to `Trap` after this commit is
that `Trap` will simply be an `enum` of trap codes with no extra
information. This commit is doubly-motivated by the desire to always use
the new `BacktraceContext` type instead of sometimes using that and
sometimes using `Trap`.
Most of the changes here were around updating `Trap::new` calls to
`bail!` calls instead. Tests which assert particular error messages
additionally often needed to use the `:?` formatter instead of the `{}`
formatter because the prior formats the whole `anyhow::Error` and the
latter only formats the top-most error, which now contains the
backtrace.
* Merge `Trap` and `TrapCode`
With prior refactorings there's no more need for `Trap` to be opaque or
otherwise contain a backtrace. This commit parse down `Trap` to simply
an `enum` which was the old `TrapCode`. All various tests and such were
updated to handle this.
The main consequence of this commit is that all errors have a
`BacktraceContext` context attached to them. This unfortunately means
that the backtrace is printed first before the error message or trap
code, but given all the prior simplifications that seems worth it at
this time.
* Rename `BacktraceContext` to `WasmBacktrace`
This feels like a better name given how this has turned out, and
additionally this commit removes having both `WasmBacktrace` and
`BacktraceContext`.
* Soup up documentation for errors and traps
* Fix build of the C API
Co-authored-by: Pat Hickey <pat@moreproductive.org>
Wiggle generates code that instruments APIs with tracing code. This is
handy for diagnosing issues at runtime, but when inspecting the output
of Wiggle, it can make the generated code difficult for a human to
decipher. This change makes tracing a default but optional feature,
allowing users to avoid tracing code with commands like `cargo expand
--no-default-features`. This should be no change for current crates
depending on `wiggle`, `wiggle-macro`, and `wiggle-generate`.
review: add 'tracing' feature to wasi-common
review: switch to using macro configuration parsing
Co-authored-by: Andrew Brown <andrew.brown@intel.com>
* wiggle: no longer need to guard wasmtime integration behind a feature
this existed so we could use wiggle in lucet, but lucet is long EOL
* replace wiggle::Trap with wiggle::wasmtime_crate::Trap
* wiggle tests: unwrap traps because we cant assert_eq on them
* wasi-common: emit a wasmtime::Trap instead of a wiggle::Trap
formally add a dependency on wasmtime here to make it obvious, though
we do now have a transitive one via wiggle no matter what (and therefore
can get rid of the default-features=false on the wiggle dep)
* wasi-nn: use wasmtime::Trap instead of wiggle::Trap
there's no way the implementation of this func is actually
a good idea, it will panic the host process on any error,
but I'll ask @mtr to fix that
* wiggle test-helpers examples: fixes
* wasi-common cant cross compile to wasm32-unknown-emscripten anymore
this was originally for the WASI polyfill for web targets. Those days
are way behind us now.
* wasmtime wont compile for armv7-unknown-linux-gnueabihf either
* Leverage Cargo's workspace inheritance feature
This commit is an attempt to reduce the complexity of the Cargo
manifests in this repository with Cargo's workspace-inheritance feature
becoming stable in Rust 1.64.0. This feature allows specifying fields in
the root workspace `Cargo.toml` which are then reused throughout the
workspace. For example this PR shares definitions such as:
* All of the Wasmtime-family of crates now use `version.workspace =
true` to have a single location which defines the version number.
* All crates use `edition.workspace = true` to have one default edition
for the entire workspace.
* Common dependencies are listed in `[workspace.dependencies]` to avoid
typing the same version number in a lot of different places (e.g. the
`wasmparser = "0.89.0"` is now in just one spot.
Currently the workspace-inheritance feature doesn't allow having two
different versions to inherit, so all of the Cranelift-family of crates
still manually specify their version. The inter-crate dependencies,
however, are shared amongst the root workspace.
This feature can be seen as a method of "preprocessing" of sorts for
Cargo manifests. This will help us develop Wasmtime but shouldn't have
any actual impact on the published artifacts -- everything's dependency
lists are still the same.
* Fix wasi-crypto tests
This commit replaces #4869 and represents the actual version bump that
should have happened had I remembered to bump the in-tree version of
Wasmtime to 1.0.0 prior to the branch-cut date. Alas!
Nick Fitzgerald
Alex Crichton
Bruce Mitchener
Shane Snover
FrankReh
Juniper Tyree
Adam C. Foltzer
Andrew Brown
Daniel Bevenius
Dan Gohman
Alphyr
Pat Hickey
Joe Shaw
wasmtime-publish
Jamey Sharp