Last minute code clean up to fix some comments and rename `address_space_size`
to `memory_reservation_size` to better describe what the option is doing.
This commit implements copying paged initialization data upon a fault of a
linear memory page.
If the initialization data is "paged", then the appropriate pages are copied
into the Wasm page (or zeroed if the page is not present in the
initialization data).
If the initialization data is not "paged", the Wasm page is zeroed so that
module instantiation can initialize the pages.
With the change to artificially limit unbounded memories based on Tunables,
it's possible to hit the assert where the minimum might exceed the static
memory bound.
This commit removes the assert in favor of a check to see if the minimum also
fits within the static memory bound. It also corrects the maximum bounding to
ensure the minimum between the memory's maximum and the configured maximum is
used.
If it does not fit, the memory will be treated as dynamic. In the case of the
pooling instance allocator, the bounds will be checked again during translation
and an appropriate error will be returned as dynamic memories are not supported
for that allocator.
This commit introduces two new methods on `InstanceAllocator`:
* `validate_module` - this method is used to validate a module after
translation but before compilation. It will be used for the upcoming pooling
allocator to ensure a module being compiled adheres to the limits of the
allocator.
* `adjust_tunables` - this method is used to adjust the `Tunables` given the
JIT compiler. The pooling allocator will use this to force all memories to
be static during compilation.
This commit refactors module instantiation in the runtime to allow for
different instance allocation strategy implementations.
It adds an `InstanceAllocator` trait with the current implementation put behind
the `OnDemandInstanceAllocator` struct.
The Wasmtime API has been updated to allow a `Config` to have an instance
allocation strategy set which will determine how instances get allocated.
This change is in preparation for an alternative *pooling* instance allocator
that can reserve all needed host process address space in advance.
This commit also makes changes to the `wasmtime_environ` crate to represent
compiled modules in a way that reduces copying at instantiation time.
This commit fully implements outer aliases of the module linking
proposal. Outer aliases can now handle multiple-level-up aliases and now
properly also handle closed-over-values of modules that are either
imported or defined.
The structure of `wasmtime::Module` was altered as part of this commit.
It is now a compiled module plus two lists of "upvars", or closed over
values used when instantiating the module. One list of upvars is
compiled artifacts which are submodules that could be used. Another is
module values that are injected via outer aliases. Serialization and
such have been updated as appropriate to handle this.
This commit updates the various tooling used by wasmtime which has new
updates to the module linking proposal. This is done primarily to sync
with WebAssembly/module-linking#26. The main change implemented here is
that wasmtime now supports creating instances from a set of values, nott
just from instantiating a module. Additionally subtyping handling of
modules with respect to imports is now properly handled by desugaring
two-level imports to imports of instances.
A number of small refactorings are included here as well, but most of
them are in accordance with the changes to `wasmparser` and the updated
binary format for module linking.
* Implement imported/exported modules/instances
This commit implements the final piece of the module linking proposal
which is to flesh out the support for importing/exporting instances and
modules. This ended up having a few changes:
* Two more `PrimaryMap` instances are now stored in an `Instance`. The value
for instances is `InstanceHandle` (pretty easy) and for modules it's
`Box<dyn Any>` (less easy).
* The custom host state for `InstanceHandle` for `wasmtime` is now
`Arc<TypeTables` to be able to fully reconstruct an instance's types
just from its instance.
* Type matching for imports now has been updated to take
instances/modules into account.
One of the main downsides of this implementation is that type matching
of imports is duplicated between wasmparser and wasmtime, leading to
posssible bugs especially in the subtelties of module linking. I'm not
sure how best to unify these two pieces of validation, however, and it
may be more trouble than it's worth.
cc #2094
* Update wat/wast/wasmparser
* Review comments
* Fix a bug in publish script to vendor the right witx
Currently there's two witx binaries in our repository given the two wasi
spec submodules, so this updates the publication script to vendor the
right one.
This commit is intended to do almost everything necessary for processing
the alias section of module linking. Most of this is internal
refactoring, the highlights being:
* Type contents are now stored separately from a `wasmtime_env::Module`.
Given that modules can freely alias types and have them used all over
the place, it seemed best to have one canonical location to type
storage which everywhere else points to (with indices). A new
`TypeTables` structure is produced during compilation which is shared
amongst all member modules in a wasm blob.
* Instantiation is heavily refactored to account for module linking. The
main gotcha here is that imports are now listed as "initializers". We
have a sort of pseudo-bytecode-interpreter which interprets the
initialization of a module. This is more complicated than just
matching imports at this point because in the module linking proposal
the module, alias, import, and instance sections may all be
interleaved. This means that imports aren't guaranteed to show up at
the beginning of the address space for modules/instances.
Otherwise most of the changes here largely fell out from these two
design points. Aliases are recorded as initializers in this scheme.
Copying around type information and/or just knowing type information
during compilation is also pretty easy since everything is just a
pointer into a `TypeTables` and we don't have to actually copy any types
themselves. Lots of various refactorings were necessary to accomodate
these changes.
Tests are hoped to cover a breadth of functionality here, but not
necessarily a depth. There's still one more piece of the module linking
proposal missing which is exporting instances/modules, which will come
in a future PR.
It's also worth nothing that there's one large TODO which isn't
implemented in this change that I plan on opening an issue for.
With module linking when a set of modules comes back from compilation
each modules has all the trampolines for the entire set of modules. This
is quite a lot of duplicate trampolines across module-linking modules.
We'll want to refactor this at some point to instead have only one set
of trampolines per set of module linking modules and have them shared
from there. I figured it was best to separate out this change, however,
since it's purely related to resource usage, and doesn't impact
non-module-linking modules at all.
cc #2094
With the module linking proposal the field name on imports is now
optional, and only the module is required to be specified. This commit
propagates this API change to the boundary of wasmtime's API, ensuring
consumers are aware of what's optional with module linking and what
isn't. Note that it's expected that all existing users will either
update accordingly or unwrap the result since module linking is
presumably disabled.
This commit adds lots of plumbing to get the type section from the
module linking proposal plumbed all the way through to the `wasmtime`
crate and the `wasmtime-c-api` crate. This isn't all that useful right
now because Wasmtime doesn't support imported/exported
modules/instances, but this is all necessary groundwork to getting that
exported at some point. I've added some light tests but I suspect the
bulk of the testing will come in a future commit.
One major change in this commit is that `SignatureIndex` no longer
follows type type index space in a wasm module. Instead a new
`TypeIndex` type is used to track that. Function signatures, still
indexed by `SignatureIndex`, are then packed together tightly.
This commit is intended to be the first of many in implementing the
module linking proposal. At this time this builds on #2059 so it
shouldn't land yet. The goal of this commit is to compile bare-bones
modules which use module linking, e.g. those with nested modules.
My hope with module linking is that almost everything in wasmtime only
needs mild refactorings to handle it. The goal is that all per-module
structures are still per-module and at the top level there's just a
`Vec` containing a bunch of modules. That's implemented currently where
`wasmtime::Module` contains `Arc<[CompiledModule]>` and an index of
which one it's pointing to. This should enable
serialization/deserialization of any module in a nested modules
scenario, no matter how you got it.
Tons of features of the module linking proposal are missing from this
commit. For example instantiation flat out doesn't work, nor does
import/export of modules or instances. That'll be coming as future
commits, but the purpose here is to start laying groundwork in Wasmtime
for handling lots of modules in lots of places.
After compilation there's actually no need to hold onto the native
signature for a wasm function type, so this commit moves out the
`ir::Signature` value from a `Module` into a separate field that's
deallocated when compilation is finished. This simplifies the
`SignatureRegistry` because it only needs to track wasm functino types
and it also means less work is done for `Func::wrap`.
This was added long ago at this point to assist with caching, but
caching has moved to a different level such that this wonky second level
of a `Module` isn't necessary. This commit removes the `ModuleLocal`
type to simplify accessors and generally make it easier to work with.
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.
* 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.
* 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
* Enable the already-passing `bulk-memoryoperations/imports.wast` test
* Implement support for the `memory.init` instruction and passive data
This adds support for passive data segments and the `memory.init` instruction
from the bulk memory operations proposal. Passive data segments are stored on
the Wasm module and then `memory.init` instructions copy their contents into
memory.
* Implement the `data.drop` instruction
This allows wasm modules to deallocate passive data segments that it doesn't
need anymore. We keep track of which segments have not been dropped on an
`Instance` and when dropping them, remove the entry from the instance's hash
map. The module always needs all of the segments for new instantiations.
* Enable final bulk memory operations spec test
This requires special casing an expected error message for an `assert_trap`,
since the expected error message contains the index of an uninitialized table
element, but our trap implementation doesn't save that diagnostic information
and shepherd it out.
* rename PassiveElemIndex to ElemIndex and same for PassiveDataIndex (#1411)
* rename PassiveDataIndex to DataIndex
* rename PassiveElemIndex to ElemIndex
* Apply renamings to wasmtime as well
* Run rustfmt
Co-authored-by: csmoe <csmoe@msn.com>
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
* 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>
* Improve handling of strings for backtraces
Largely avoid storing strings at all in the `wasmtime-*` internal
crates, and instead only store strings in a separate global cache
specific to the `wasmtime` crate itself. This global cache is inserted
and removed from dynamically as modules are created and deallocated, and
the global cache is consulted whenever a `Trap` is created to
symbolicate any wasm frames.
This also avoids the need to thread `module_name` through the jit crates
and back, and additionally removes the need for `ModuleSyncString`.
* Run rustfmt
This commit fixes the `wasmtime::Instance` instantiation API when
imports have the same name but might be imported under different types.
This is handled in the API by listing imports as a list instead of as a
name map, but they were interpreted as a name map under the hood causing
collisions.
This commit now keeps track of the index used to define each import, and
the index is passed through in the `Resolver`. Existing implementaitons
of `Resolver` all ignore this, but the API now uses it exclusivley to
match up `Extern` definitions to imports.
* Migrate back to `std::` stylistically
This commit moves away from idioms such as `alloc::` and `core::` as
imports of standard data structures and types. Instead it migrates all
crates to uniformly use `std::` for importing standard data structures
and types. This also removes the `std` and `core` features from all
crates to and removes any conditional checking for `feature = "std"`
All of this support was previously added in #407 in an effort to make
wasmtime/cranelift "`no_std` compatible". Unfortunately though this
change comes at a cost:
* The usage of `alloc` and `core` isn't idiomatic. Especially trying to
dual between types like `HashMap` from `std` as well as from
`hashbrown` causes imports to be surprising in some cases.
* Unfortunately there was no CI check that crates were `no_std`, so none
of them actually were. Many crates still imported from `std` or
depended on crates that used `std`.
It's important to note, however, that **this does not mean that wasmtime
will not run in embedded environments**. The style of the code today and
idioms aren't ready in Rust to support this degree of multiplexing and
makes it somewhat difficult to keep up with the style of `wasmtime`.
Instead it's intended that embedded runtime support will be added as
necessary. Currently only `std` is necessary to build `wasmtime`, and
platforms that natively need to execute `wasmtime` will need to use a
Rust target that supports `std`. Note though that not all of `std` needs
to be supported, but instead much of it could be configured off to
return errors, and `wasmtime` would be configured to gracefully handle
errors.
The goal of this PR is to move `wasmtime` back to idiomatic usage of
features/`std`/imports/etc and help development in the short-term.
Long-term when platform concerns arise (if any) they can be addressed by
moving back to `no_std` crates (but fixing the issues mentioned above)
or ensuring that the target in Rust has `std` available.
* Start filling out platform support doc
