* Expose memory-related options in `Config`
This commit was initially motivated by looking more into #1501, but it
ended up balooning a bit after finding a few issues. The high-level
items in this commit are:
* New configuration options via `wasmtime::Config` are exposed to
configure the tunable limits of how memories are allocated and such.
* The `MemoryCreator` trait has been updated to accurately reflect the
required allocation characteristics that JIT code expects.
* A bug has been fixed in the cranelift wasm code generation where if no
guard page was present bounds checks weren't accurately performed.
The new `Config` methods allow tuning the memory allocation
characteristics of wasmtime. Currently 64-bit platforms will reserve 6GB
chunks of memory for each linear memory, but by tweaking various config
options you can change how this is allocate, perhaps at the cost of
slower JIT code since it needs more bounds checks. The methods are
intended to be pretty thoroughly documented as to the effect they have
on the JIT code and what values you may wish to select. These new
methods have been added to the spectest fuzzer to ensure that various
configuration values for these methods don't affect correctness.
The `MemoryCreator` trait previously only allocated memories with a
`MemoryType`, but this didn't actually reflect the guarantees that JIT
code expected. JIT code is generated with an assumption about the
minimum size of the guard region, as well as whether memory is static or
dynamic (whether the base pointer can be relocated). These properties
must be upheld by custom allocation engines for JIT code to perform
correctly, so extra parameters have been added to
`MemoryCreator::new_memory` to reflect this.
Finally the fuzzing with `Config` turned up an issue where if no guard
pages present the wasm code wouldn't correctly bounds-check memory
accesses. The issue here was that with a guard page we only need to
bounds-check the first byte of access, but without a guard page we need
to bounds-check the last byte of access. This meant that the code
generation needed to account for the size of the memory operation
(load/store) and use this as the offset-to-check in the no-guard-page
scenario. I've attempted to make the various comments in cranelift a bit
more exhaustive too to hopefully make it a bit clearer for future
readers!
Closes#1501
* Review comments
* Update a comment
* Revamp memory management of `InstanceHandle`
This commit fixes a known but in Wasmtime where an instance could still
be used after it was freed. Unfortunately the fix here is a bit of a
hammer, but it's the best that we can do for now. The changes made in
this commit are:
* A `Store` now stores all `InstanceHandle` objects it ever creates.
This keeps all instances alive unconditionally (along with all host
functions and such) until the `Store` is itself dropped. Note that a
`Store` is reference counted so basically everything has to be dropped
to drop anything, there's no longer any partial deallocation of instances.
* The `InstanceHandle` type's own reference counting has been removed.
This is largely redundant with what's already happening in `Store`, so
there's no need to manage two reference counts.
* Each `InstanceHandle` no longer tracks its dependencies in terms of
instance handles. This set was actually inaccurate due to dynamic
updates to tables and such, so we needed to revamp it anyway.
* Initialization of an `InstanceHandle` is now deferred until after
`InstanceHandle::new`. This allows storing the `InstanceHandle` before
side-effectful initialization, such as copying element segments or
running the start function, to ensure that regardless of the result of
instantiation the underlying `InstanceHandle` is still available to
persist in storage.
Overall this should fix a known possible way to safely segfault Wasmtime
today (yay!) and it should also fix some flaikness I've seen on CI.
Turns out one of the spec tests
(bulk-memory-operations/partial-init-table-segment.wast) exercises this
functionality and we were hitting sporating use-after-free, but only on
Windows.
* Shuffle some APIs around
* Comment weak cycle
* Implement interrupting wasm code, reimplement stack overflow
This commit is a relatively large change for wasmtime with two main
goals:
* Primarily this enables interrupting executing wasm code with a trap,
preventing infinite loops in wasm code. Note that resumption of the
wasm code is not a goal of this commit.
* Additionally this commit reimplements how we handle stack overflow to
ensure that host functions always have a reasonable amount of stack to
run on. This fixes an issue where we might longjmp out of a host
function, skipping destructors.
Lots of various odds and ends end up falling out in this commit once the
two goals above were implemented. The strategy for implementing this was
also lifted from Spidermonkey and existing functionality inside of
Cranelift. I've tried to write up thorough documentation of how this all
works in `crates/environ/src/cranelift.rs` where gnarly-ish bits are.
A brief summary of how this works is that each function and each loop
header now checks to see if they're interrupted. Interrupts and the
stack overflow check are actually folded into one now, where function
headers check to see if they've run out of stack and the sentinel value
used to indicate an interrupt, checked in loop headers, tricks functions
into thinking they're out of stack. An interrupt is basically just
writing a value to a location which is read by JIT code.
When interrupts are delivered and what triggers them has been left up to
embedders of the `wasmtime` crate. The `wasmtime::Store` type has a
method to acquire an `InterruptHandle`, where `InterruptHandle` is a
`Send` and `Sync` type which can travel to other threads (or perhaps
even a signal handler) to get notified from. It's intended that this
provides a good degree of flexibility when interrupting wasm code. Note
though that this does have a large caveat where interrupts don't work
when you're interrupting host code, so if you've got a host import
blocking for a long time an interrupt won't actually be received until
the wasm starts running again.
Some fallout included from this change is:
* Unix signal handlers are no longer registered with `SA_ONSTACK`.
Instead they run on the native stack the thread was already using.
This is possible since stack overflow isn't handled by hitting the
guard page, but rather it's explicitly checked for in wasm now. Native
stack overflow will continue to abort the process as usual.
* Unix sigaltstack management is now no longer necessary since we don't
use it any more.
* Windows no longer has any need to reset guard pages since we no longer
try to recover from faults on guard pages.
* On all targets probestack intrinsics are disabled since we use a
different mechanism for catching stack overflow.
* The C API has been updated with interrupts handles. An example has
also been added which shows off how to interrupt a module.
Closes#139Closes#860Closes#900
* Update comment about magical interrupt value
* Store stack limit as a global value, not a closure
* Run rustfmt
* Handle review comments
* Add a comment about SA_ONSTACK
* Use `usize` for type of `INTERRUPTED`
* Parse human-readable durations
* Bring back sigaltstack handling
Allows libstd to print out stack overflow on failure still.
* Add parsing and emission of stack limit-via-preamble
* Fix new example for new apis
* Fix host segfault test in release mode
* Fix new doc example
* 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.
This commit makes the following changes to unwind information generation in
Cranelift:
* Remove frame layout change implementation in favor of processing the prologue
and epilogue instructions when unwind information is requested. This also
means this work is no longer performed for Windows, which didn't utilize it.
It also helps simplify the prologue and epilogue generation code.
* Remove the unwind sink implementation that required each unwind information
to be represented in final form. For FDEs, this meant writing a
complete frame table per function, which wastes 20 bytes or so for each
function with duplicate CIEs. This also enables Cranelift users to collect the
unwind information and write it as a single frame table.
* For System V calling convention, the unwind information is no longer stored
in code memory (it's only a requirement for Windows ABI to do so). This allows
for more compact code memory for modules with a lot of functions.
* Deletes some duplicate code relating to frame table generation. Users can
now simply use gimli to create a frame table from each function's unwind
information.
Fixes#1181.
* Consolidate trap/frame information
This commit removes `TrapRegistry` in favor of consolidating this
information in the `FRAME_INFO` we already have in the `wasmtime` crate.
This allows us to keep information generally in one place and have one
canonical location for "map this PC to some original wasm stuff". The
intent for this is to next update with enough information to go from a
program counter to a position in the original wasm file.
* Expose module offset information in `FrameInfo`
This commit implements functionality for `FrameInfo`, the wasm stack
trace of a `Trap`, to return the module/function offset. This allows
knowing the precise wasm location of each stack frame, instead of only
the main trap itself. The intention here is to provide more visibility
into the wasm source when something traps, so you know precisely where
calls were and where traps were, in order to assist in debugging.
Eventually we might use this information for mapping back to native
source languages as well (given sufficient debug information).
This change makes a previously-optional artifact of compilation always
computed on the cranelift side of things. This `ModuleAddressMap` is
then propagated to the same store of information other frame information
is stored within. This also removes the need for passing a `SourceLoc`
with wasm traps or to wasm trap creation, since the backtrace's wasm
frames will be able to infer their own `SourceLoc` from the relevant
program counters.
Preserve FPRs as required by the Windows fastcall calling convention.
This exposes an implementation limit due to Cranelift's approach to stack layout, which conflicts with expectations Windows makes in SEH layout - functions where the Cranelift user desires fastcall unwind information, that require preservation of an ABI-reserved FPR, that have a stack frame 240 bytes or larger, now produce an error when compiled. Several wasm spectests were disabled because they would trip this limit. This is a temporary constraint that should be fixed promptly.
Co-authored-by: bjorn3 <bjorn3@users.noreply.github.com>
* Option for host managed memory
* Rename Allocator to MemoryCreator
* Create LinearMemory and MemoryCreator traits in api
* Leave only one as_ptr function in LinearMemory trait
* Memory creator test
* Update comments/docs for LinearMemory and MemoryCreator traits
* Add guard page to the custom memory example
* Remove mut from LinearMemory trait as_ptr
* Host_memory_grow test
* 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
* 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
* 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>
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.
* 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>
* 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
* 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
* 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
* 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
* 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.
* Improve panics/traps from imported functions
This commit performs a few refactorings and fixes a bug as well. The
changes here are:
* The `thread_local!` in the `wasmtime` crate for trap information is
removed. The thread local in the `wasmtime_runtime` crate is now
leveraged to transmit trap information.
* Panics in user-provided functions are now caught explicitly to be
carried across JIT code manually. Getting Rust panics unwinding
through JIT code is pretty likely to be super tricky and difficult to
do, so in the meantime we can get by with catching panics and resuming
the panic once we've resumed in Rust code.
* Various take/record trap apis have all been removed in favor of
working directly with `Trap` objects, where the internal trap object
has been expanded slightly to encompass user-provided errors as well.
This borrows a bit #839 and otherwise will...
Closes#848
* Rename `r#return` to `ret`
* Reel in unsafety around `InstanceHandle`
This commit is an attempt, or at least is targeted at being a start, at
reeling in the unsafety around the `InstanceHandle` type. Currently this
type represents a sort of moral `Rc<Instance>` but is a bit more
specialized since the underlying memory is allocated through mmap.
Additionally, though, `InstanceHandle` exposes a fundamental flaw in its
safety by safetly allowing mutable access so long as you have `&mut
InstanceHandle`. This type, however, is trivially created by simply
cloning a `InstanceHandle` to get an owned reference. This means that
`&mut InstanceHandle` does not actually provide any guarantees about
uniqueness, so there's no more safety than `&InstanceHandle` itself.
This commit removes all `&mut self` APIs from `InstanceHandle`,
additionally removing some where `&self` was `unsafe` and `&mut self`
was safe (since it was trivial to subvert this "safety"). In doing so
interior mutability patterns are now used much more extensively through
structures such as `Table` and `Memory`. Additionally a number of
methods were refactored to be a bit clearer and use helper functions
where possible.
This is a relatively large commit unfortunately, but it snowballed very
quickly into touching quite a few places. My hope though is that this
will prevent developers working on wasmtime internals as well as
developers still yet to migrate to the `wasmtime` crate from falling
into trivial unsafe traps by accidentally using `&mut` when they can't.
All existing users relying on `&mut` will need to migrate to some form
of interior mutability, such as using `RefCell` or `Cell`.
This commit also additionally marks `InstanceHandle::new` as an `unsafe`
function. The rationale for this is that the `&mut`-safety is only the
beginning for the safety of `InstanceHandle`. In general the wasmtime
internals are extremely unsafe and haven't been audited for appropriate
usage of `unsafe`. Until that's done it's hoped that we can warn users
with this `unsafe` constructor and otherwise push users to the
`wasmtime` crate which we know is safe.
* Fix windows build
* Wrap up mutable memory state in one structure
Rather than having separate fields
* Use `Cell::set`, not `Cell::replace`, where possible
* Add a helper function for offsets from VMContext
* Fix a typo from merging
* rustfmt
* Use try_from, not as
* Tweak style of some setters
* 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 removes the `signature_cache` field from the `Store` type
and performs a few internal changes which are aimed to be a bit forward
looking towards #777, making `Store` threadsafe.
The changes made here are:
* The `SignatureRegistry` internal type now contains the reverse map
that `signature_cache` was serving to do. This is populated on calls
to `register` automatically and is accompanied by a `lookup` method as
well.
* The `register_wasmtime_signature` and `lookup_wasmtime_signature`
methods were removed from `Store` and now instead work by using the
`Compiler::signatures` field.
* The `SignatureRegistry` type was updated to have interior mutability.
The global `Compiler` type is highly likely to get shared across many
threads through `Store`, so it needs some form of lock somewhere for
mutation of the registry of signatures and this commit opts to put it
inside `SignatureRegistry` which will eventually allow for the removal
of most `&mut self` method on `Compiler`.
* Replace the global-exports mechanism with a caller-vmctx mechanism.
This eliminates the global exports mechanism, and instead adds a
caller-vmctx argument to wasm functions so that WASI can obtain the
memory and other things from the caller rather than looking them up in a
global registry.
This replaces #390.
* Fixup some merge conflicts
* Rustfmt
* Ensure VMContext is aligned to 16 bytes
With the removal of `global_exports` it "just so happens" that this
isn't happening naturally any more.
* Fixup some bugs with double vmctx in wasmtime crate
* Trampoline stub needed adjusting
* Use pointer type instead of always using I64 for caller vmctx
* Don't store `ir::Signature` in `Func` since we don't know the pointer
size at creation time.
* Skip the first 2 arguments in IR signatures since that's the two vmctx
parameters.
* Update cranelift to 0.56.0
* Handle more merge conflicts
* Rustfmt
Co-authored-by: Alex Crichton <alex@alexcrichton.com>
* Document and update the API of the `externals.rs` module
This commit ensures that all public methods and items are documented in
the `externals.rs` module, notably all external values that can be
imported and exported in WebAssembly. Along the way this also tidies up
the API and fixes a few bugs:
* `Global::new` now returns a `Result` and fails if the provided value
does not match the type of the global.
* `Global::set` now returns a `Result` and fails if the global is either
immutable or the provided value doesn't match the type of the global.
* `Table::new` now fails if the provided initializer does not match the
element type.
* `Table::get` now returns `Option<Val>` instead of implicitly returning
null.
* `Table::set` now returns `Result<()>`, returning an error on out of
bounds or if the input type is of the wrong type.
* `Table::grow` now returns `Result<u32>`, returning the previous number
of table elements if succesful or an error if the maximum is reached
or the initializer value is of the wrong type. Additionally a bug was
fixed here where if the wrong initializer was provided the table would
be grown still, but initialization would fail.
* `Memory::data` was renamed to `Memory::data_unchecked_mut`.
Additionally `Memory::data_unchecked` was added. Lots of caveats were
written down about how using the method can go wrong.
* `Memory::grow` now returns `Result<u32>`, returning an error if growth
fails or the number of pages previous the growth if successful.
* Run rustfmt
* Fix another test
* Update crates/api/src/externals.rs
Co-Authored-By: Sergei Pepyakin <s.pepyakin@gmail.com>
Co-authored-by: Sergei Pepyakin <s.pepyakin@gmail.com>
In preparation for eventual support for wasm interface types this commit
moves around a few panics internally inside of conversions between the
`wasmtime` crate and the underlying jit support crates. This should have
any immediately-visible user changes, but the goal is that this'll help
support interface types which means `wasmtime` will have types that are
not supported by wasmtime itself and we'll be able to more gracefully
support that with error messages instead of accidental panics.
* Remove unsafety from `Trap` API
This commit removes the `unsafe impl Send` for `Trap` by removing the
internal `HostRef` and leaving `HostRef` entirely as an implementation
detail of the C API.
cc #708
* Run rustfmt
* Remove the need for `HostRef<Store>`
This commit goes through the public API of the `wasmtime` crate and
removes the need for `HostRef<Store>`, as discussed in #708. This commit
is accompanied with a few changes:
* The `Store` type now also implements `Default`, creating a new
`Engine` with default settings and returning that.
* The `Store` type now implements `Clone`, and is documented as being a
"cheap clone" aka being reference counted. As before there is no
supported way to create a deep clone of a `Store`.
* All APIs take/return `&Store` or `Store` instead of `HostRef<Store>`,
and `HostRef<T>` is left as purely a detail of the C API.
* The `global_exports` function is tagged as `#[doc(hidden)]` for now
while we await its removal.
* The `Store` type is not yet `Send` nor `Sync` due to the usage of
`global_exports`, but it is intended to become so eventually.
* Touch up comments on some examples
* Run rustfmt
* Update the `*.wast` runner to use the `wasmtime` API
This commit migrates the `wasmtime-wast` crate, which executes `*.wast`
test suites, to use the `wasmtime` crate exclusively instead of the raw
support provided by the `wasmtime-*` family of crates.
The primary motivation for this change is to use `*.wast` test to test
the support for interface types, but interface types is only being added
in the `wasmtime` crate for now rather than all throughout the core
crates. This means that without this transition it's much more difficult
to write tests for wasm interface types!
A secondary motivation for this is that it's testing the support we
provide to users through the `wasmtime` crate, since that's the
expectation of what most users would use rather than the raw
`wasmtime-*` crates.
* Run rustfmt
* Fix the multi example
* Handle v128 values in the `wasmtime` crate
Ensure that we allocate 128-bit stack slots instead of 64-bit stack
slots.
* Update to master
* Add comment
* Refactor the `types.rs` types and structures
A few changes applied along the way:
* Documentation added to most methods and types.
* Limits are now stored with the maximum as optional rather than a
sentinel u32 value for `None`.
* The `Name` type was removed in favor of just using a bare `String`.
* The `Extern` prefix in the varaints of `ExternType` has been removed
since it was redundant.
* Accessors of `ExternType` variants no longer panic, and unwrapping
versions were added with "unwrap" in the name.
* Fields and methods named `r#type` were renamed to `ty` to avoid
requiring a raw identifier to use them.
* Remove `fail-fast: false`
This was left around since the development of GitHub Actions for
wasmtime, but they're no longer needed!
* Fix compilation of the test-programs code
* Fix compilation of wasmtime-py package
* Run rustfmt
* Tweak the API of the `Val` type
A few updates to the API of the `Val` type:
* Added a payload for `V128`.
* Replace existing accessor methods with `Option`-returning versions.
* Add `unwrap_xxx` family of methods to extract a value and panic.
* Remove `Into` conversions which panic, since panicking in `From` or
`Into` isn't idiomatic in Rust
* Add documentation to all methods/values/enums/etc.
* Rename `Val::default` to `Val::null`
* Run rustfmt
* Review comments
* 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
As discussed in https://github.com/bytecodealliance/cranelift/pull/1226, the context of Cranelift errors is lost after exiting the scope containing the Cranelift function. `CodegenError` then only contains something like `inst2: arg 0 (v4) has type i16x8, expected i8x16`, which is rarely enough information for investigating a codegen failure. This change uses Cranelift's `pretty_error` function to improve the error messages wrapped in `CompileError`; `CompileError` has lost the reference to `CodegenError` due to `pretty_error` taking ownership but this seems preferable since no backtrace is attached and losing the pretty-printed context would be worse (if `CodegenError` gains a `Backtrace` or implements `Clone` we can revisit this).
