* Move function names out of `Module`
This commit moves function names in a module out of the
`wasmtime_environ::Module` type and into separate sections stored in the
final compiled artifact. Spurred on by #3787 to look at module load
times I noticed that a huge amount of time was spent in deserializing
this map. The `spidermonkey.wasm` file, for example, has a 3MB name
section which is a lot of unnecessary data to deserialize at module load
time.
The names of functions are now split out into their own dedicated
section of the compiled artifact and metadata about them is stored in a
more compact format at runtime by avoiding a `BTreeMap` and instead
using a sorted array. Overall this improves deserialize times by up to
80% for modules with large name sections since the name section is no
longer deserialized at load time and it's lazily paged in as names are
actually referenced.
* Fix a typo
* Fix compiled module determinism
Need to not only sort afterwards but also first to ensure the data of
the name section is consistent.
During instance initialization, we build two sorts of arrays eagerly:
- We create an "anyfunc" (a `VMCallerCheckedAnyfunc`) for every function
in an instance.
- We initialize every element of a funcref table with an initializer to
a pointer to one of these anyfuncs.
Most instances will not touch (via call_indirect or table.get) all
funcref table elements. And most anyfuncs will never be referenced,
because most functions are never placed in tables or used with
`ref.func`. Thus, both of these initialization tasks are quite wasteful.
Profiling shows that a significant fraction of the remaining
instance-initialization time after our other recent optimizations is
going into these two tasks.
This PR implements two basic ideas:
- The anyfunc array can be lazily initialized as long as we retain the
information needed to do so. For now, in this PR, we just recreate the
anyfunc whenever a pointer is taken to it, because doing so is fast
enough; in the future we could keep some state to know whether the
anyfunc has been written yet and skip this work if redundant.
This technique allows us to leave the anyfunc array as uninitialized
memory, which can be a significant savings. Filling it with
initialized anyfuncs is very expensive, but even zeroing it is
expensive: e.g. in a large module, it can be >500KB.
- A funcref table can be lazily initialized as long as we retain a link
to its corresponding instance and function index for each element. A
zero in a table element means "uninitialized", and a slowpath does the
initialization.
Funcref tables are a little tricky because funcrefs can be null. We need
to distinguish "element was initially non-null, but user stored explicit
null later" from "element never touched" (ie the lazy init should not
blow away an explicitly stored null). We solve this by stealing the LSB
from every funcref (anyfunc pointer): when the LSB is set, the funcref
is initialized and we don't hit the lazy-init slowpath. We insert the
bit on storing to the table and mask it off after loading.
We do have to set up a precomputed array of `FuncIndex`s for the table
in order for this to work. We do this as part of the module compilation.
This PR also refactors the way that the runtime crate gains access to
information computed during module compilation.
Performance effect measured with in-tree benches/instantiation.rs, using
SpiderMonkey built for WASI, and with memfd enabled:
```
BEFORE:
sequential/default/spidermonkey.wasm
time: [68.569 us 68.696 us 68.856 us]
sequential/pooling/spidermonkey.wasm
time: [69.406 us 69.435 us 69.465 us]
parallel/default/spidermonkey.wasm: with 1 background thread
time: [69.444 us 69.470 us 69.497 us]
parallel/default/spidermonkey.wasm: with 16 background threads
time: [183.72 us 184.31 us 184.89 us]
parallel/pooling/spidermonkey.wasm: with 1 background thread
time: [69.018 us 69.070 us 69.136 us]
parallel/pooling/spidermonkey.wasm: with 16 background threads
time: [326.81 us 337.32 us 347.01 us]
WITH THIS PR:
sequential/default/spidermonkey.wasm
time: [6.7821 us 6.8096 us 6.8397 us]
change: [-90.245% -90.193% -90.142%] (p = 0.00 < 0.05)
Performance has improved.
sequential/pooling/spidermonkey.wasm
time: [3.0410 us 3.0558 us 3.0724 us]
change: [-95.566% -95.552% -95.537%] (p = 0.00 < 0.05)
Performance has improved.
parallel/default/spidermonkey.wasm: with 1 background thread
time: [7.2643 us 7.2689 us 7.2735 us]
change: [-89.541% -89.533% -89.525%] (p = 0.00 < 0.05)
Performance has improved.
parallel/default/spidermonkey.wasm: with 16 background threads
time: [147.36 us 148.99 us 150.74 us]
change: [-18.997% -18.081% -17.285%] (p = 0.00 < 0.05)
Performance has improved.
parallel/pooling/spidermonkey.wasm: with 1 background thread
time: [3.1009 us 3.1021 us 3.1033 us]
change: [-95.517% -95.511% -95.506%] (p = 0.00 < 0.05)
Performance has improved.
parallel/pooling/spidermonkey.wasm: with 16 background threads
time: [49.449 us 50.475 us 51.540 us]
change: [-85.423% -84.964% -84.465%] (p = 0.00 < 0.05)
Performance has improved.
```
So an improvement of something like 80-95% for a very large module (7420
functions in its one funcref table, 31928 functions total).
This commit fixes a panic which can happen on a module with an invalid
name section where one of the functions named has the index `u32::MAX`.
Previously Wasmtime would create a new `FuncIndex` with the indices
found in the name section but the sentinel `u32::MAX` causes a panic.
Cranelift otherwise limits the number of functions through `wasmparser`
which has a hard limit (lower than `u32::MAX`) so this commit applies a
fix of only recording function names for function indices that are
actually present in the module.
* Update the spec reference testsuite submodule
This commit brings in recent updates to the spec test suite. Most of the
changes here were already fixed in `wasmparser` with some tweaks to
esoteric modules, but Wasmtime also gets a bug fix where where import
matching for the size of tables/memories is based on the current runtime
size of the table/memory rather than the original type of the
table/memory. This means that during type matching the actual value is
consulted for its size rather than using the minimum size listed in its
type.
* Fix now-missing directories in build script
We _must not_ trigger a GC when moving refs from host code into
Wasm (e.g. returned from a host function or passed as arguments to a Wasm
function). After insertion into the table, this reference is no longer
rooted. If multiple references are being sent from the host into Wasm and we
allowed GCs during insertion, then the following events could happen:
* Reference A is inserted into the activations table. This does not trigger a
GC, but does fill the table to capacity.
* The caller's reference to A is removed. Now the only reference to A is from
the activations table.
* Reference B is inserted into the activations table. Because the table is at
capacity, a GC is triggered.
* A is reclaimed because the only reference keeping it alive was the activation
table's reference (it isn't inside any Wasm frames on the stack yet, so stack
scanning and stack maps don't increment its reference count).
* We transfer control to Wasm, giving it A and B. Wasm uses A. That's a use
after free.
To prevent uses after free, we cannot GC when moving refs into the
`VMExternRefActivationsTable` because we are passing them from the host to Wasm.
On the other hand, when we are *cloning* -- as opposed to moving -- refs from
the host to Wasm, then it is fine to GC while inserting into the activations
table, because the original referent that we are cloning from is still alive and
rooting the ref.
* Remove some allocations in `CodeMemory`
This commit removes the `FinishedFunctions` type as well as allocations
associated with trampolines when allocating inside of a `CodeMemory`.
The main goal of this commit is to improve the time spent in
`CodeMemory` where currently today a good portion of time is spent
simply parsing symbol names and trying to extract function indices from
them. Instead this commit implements a new strategy (different from #3236)
where compilation records offset/length information for all
functions/trampolines so this doesn't need to be re-learned from the
object file later.
A consequence of this commit is that this offset information will be
decoded/encoded through `bincode` unconditionally, but we can also
optimize that later if necessary as well.
Internally this involved quite a bit of refactoring since the previous
map for `FinishedFunctions` was relatively heavily relied upon.
* comments
* Reduce indentation in `to_paged`
Use a few early-returns from `match` to avoid lots of extra indentation.
* Move wasm data sections out of `wasmtime_environ::Module`
This is the first step down the road of #3230. The long-term goal is
that `Module` is always `bincode`-decoded, but wasm data segments are a
possibly very-large portion of this residing in modules which we don't
want to shove through bincode. This refactors the internals of wasmtime
to be ok with this data living separately from the `Module` itself,
providing access at necessary locations.
Wasm data segments are now extracted from a wasm module and
concatenated directly. Data sections then describe ranges within this
concatenated list of data, and passive data works the same way. This
implementation does not lend itself to eventually optimizing the case
where passive data is dropped and no longer needed. That's left for a
future PR.
* Move `CompiledFunction` into wasmtime-cranelift
This commit moves the `wasmtime_environ::CompiledFunction` type into the
`wasmtime-cranelift` crate. This type has lots of Cranelift-specific
pieces of compilation and doesn't need to be generated by all Wasmtime
compilers. This replaces the usage in the `Compiler` trait with a
`Box<Any>` type that each compiler can select. Each compiler must still
produce a `FunctionInfo`, however, which is shared information we'll
deserialize for each module.
The `wasmtime-debug` crate is also folded into the `wasmtime-cranelift`
crate as a result of this commit. One possibility was to move the
`CompiledFunction` commit into its own crate and have `wasmtime-debug`
depend on that, but since `wasmtime-debug` is Cranelift-specific at this
time it didn't seem like it was too too necessary to keep it separate.
If `wasmtime-debug` supports other backends in the future we can
recreate a new crate, perhaps with it refactored to not depend on
Cranelift.
* Move wasmtime_environ::reference_type
This now belongs in wasmtime-cranelift and nowhere else
* Remove `Type` reexport in wasmtime-environ
One less dependency on `cranelift-codegen`!
* Remove `types` reexport from `wasmtime-environ`
Less cranelift!
* Remove `SourceLoc` from wasmtime-environ
Change the `srcloc`, `start_srcloc`, and `end_srcloc` fields to a custom
`FilePos` type instead of `ir::SourceLoc`. These are only used in a few
places so there's not much to lose from an extra abstraction for these
leaf use cases outside of cranelift.
* Remove wasmtime-environ's dep on cranelift's `StackMap`
This commit "clones" the `StackMap` data structure in to
`wasmtime-environ` to have an independent representation that that
chosen by Cranelift. This allows Wasmtime to decouple this runtime
dependency of stack map information and let the two evolve
independently, if necessary.
An alternative would be to refactor cranelift's implementation into a
separate crate and have wasmtime depend on that but it seemed a bit like
overkill to do so and easier to clone just a few lines for this.
* Define code offsets in wasmtime-environ with `u32`
Don't use Cranelift's `binemit::CodeOffset` alias to define this field
type since the `wasmtime-environ` crate will be losing the
`cranelift-codegen` dependency soon.
* Commit to using `cranelift-entity` in Wasmtime
This commit removes the reexport of `cranelift-entity` from the
`wasmtime-environ` crate and instead directly depends on the
`cranelift-entity` crate in all referencing crates. The original reason
for the reexport was to make cranelift version bumps easier since it's
less versions to change, but nowadays we have a script to do that.
Otherwise this encourages crates to use whatever they want from
`cranelift-entity` since we'll always depend on the whole crate.
It's expected that the `cranelift-entity` crate will continue to be a
lean crate in dependencies and suitable for use at both runtime and
compile time. Consequently there's no need to avoid its usage in
Wasmtime at runtime, since "remove Cranelift at compile time" is
primarily about the `cranelift-codegen` crate.
* Remove most uses of `cranelift-codegen` in `wasmtime-environ`
There's only one final use remaining, which is the reexport of
`TrapCode`, which will get handled later.
* Limit the glob-reexport of `cranelift_wasm`
This commit removes the glob reexport of `cranelift-wasm` from the
`wasmtime-environ` crate. This is intended to explicitly define what
we're reexporting and is a transitionary step to curtail the amount of
dependencies taken on `cranelift-wasm` throughout the codebase. For
example some functions used by debuginfo mapping are better imported
directly from the crate since they're Cranelift-specific. Note that
this is intended to be a temporary state affairs, soon this reexport
will be gone entirely.
Additionally this commit reduces imports from `cranelift_wasm` and also
primarily imports from `crate::wasm` within `wasmtime-environ` to get a
better sense of what's imported from where and what will need to be
shared.
* Extract types from cranelift-wasm to cranelift-wasm-types
This commit creates a new crate called `cranelift-wasm-types` and
extracts type definitions from the `cranelift-wasm` crate into this new
crate. The purpose of this crate is to be a shared definition of wasm
types that can be shared both by compilers (like Cranelift) as well as
wasm runtimes (e.g. Wasmtime). This new `cranelift-wasm-types` crate
doesn't depend on `cranelift-codegen` and is the final step in severing
the unconditional dependency from Wasmtime to `cranelift-codegen`.
The final refactoring in this commit is to then reexport this crate from
`wasmtime-environ`, delete the `cranelift-codegen` dependency, and then
update all `use` paths to point to these new types.
The main change of substance here is that the `TrapCode` enum is
mirrored from Cranelift into this `cranelift-wasm-types` crate. While
this unfortunately results in three definitions (one more which is
non-exhaustive in Wasmtime itself) it's hopefully not too onerous and
ideally something we can patch up in the future.
* Get lightbeam compiling
* Remove unnecessary dependency
* Fix compile with uffd
* Update publish script
* Fix more uffd tests
* Rename cranelift-wasm-types to wasmtime-types
This reflects the purpose a bit more where it's types specifically
intended for Wasmtime and its support.
* Fix publish script
The main purpose for doing this is that this is a large piece of
functionality used by Wasmtime which is entirely independent of
Cranelift. Eventually Wasmtime wants to be able to compile without
Cranelift, but it can't also depend on `cranelift-wasm` in that
situation for module translation which means that something needs to
happen. One option is to refactor what's in `cranelift-wasm` into a
separate crate (since all these pieces don't actually depend on
`cranelift-codegen`), but I personally chose to not do this because:
* The `ModuleEnvironment` trait, AFAIK, only has a primary user of
Wasmtime. The Spidermonkey integration, for example, does not use this.
* This is an extra layer of abstraction between Wasmtime and the
compilation phase which was a bit of a pain to maintain. It couldn't
be Wasmtime-specific as it was part of Cranelift but at the same time
it had lots of Wasmtime-centric functionality (such as module
linking).
* Updating the "dummy" implementation has become pretty onerous over
time as frequent additions are made and the "dummy" implementation was
never actually used anywhere. This ended up feeling like effectively
busy-work to update this.
For these reasons I've opted to to move the meat of `cranelift-wasm`
used by `wasmtime-environ` directly into `wasmtime-environ`. This means
that the only real meat that Wasmtime uses from `cranelift-wasm` is the
function-translation bits in the `wasmtime-cranelift` crate.
The changes in `wasmtime-environ` are largely to inline module parsing
together so it's a bit easier to follow instead of trying to connect
the dots between lots of various function calls.
This commit started off by deleting the `cranelift_codegen::settings`
reexport in the `wasmtime-environ` crate and then basically played
whack-a-mole until everything compiled again. The main result of this is
that the `wasmtime-*` family of crates have generally less of a
dependency on the `TargetIsa` trait and type from Cranelift. While the
dependency isn't entirely severed yet this is at least a significant
start.
This commit is intended to be largely refactorings, no functional
changes are intended here. The refactorings are:
* A `CompilerBuilder` trait has been added to `wasmtime_environ` which
server as an abstraction used to create compilers and configure them
in a uniform fashion. The `wasmtime::Config` type now uses this
instead of cranelift-specific settings. The `wasmtime-jit` crate
exports the ability to create a compiler builder from a
`CompilationStrategy`, which only works for Cranelift right now. In a
cranelift-less build of Wasmtime this is expected to return a trait
object that fails all requests to compile.
* The `Compiler` trait in the `wasmtime_environ` crate has been souped
up with a number of methods that Wasmtime and other crates needed.
* The `wasmtime-debug` crate is now moved entirely behind the
`wasmtime-cranelift` crate.
* The `wasmtime-cranelift` crate is now only depended on by the
`wasmtime-jit` crate.
* Wasm types in `cranelift-wasm` no longer contain their IR type,
instead they only contain the `WasmType`. This is required to get
everything to align correctly but will also be required in a future
refactoring where the types used by `cranelift-wasm` will be extracted
to a separate crate.
* I moved around a fair bit of code in `wasmtime-cranelift`.
* Some gdb-specific jit-specific code has moved from `wasmtime-debug` to
`wasmtime-jit`.
* Implement the memory64 proposal in Wasmtime
This commit implements the WebAssembly [memory64 proposal][proposal] in
both Wasmtime and Cranelift. In terms of work done Cranelift ended up
needing very little work here since most of it was already prepared for
64-bit memories at one point or another. Most of the work in Wasmtime is
largely refactoring, changing a bunch of `u32` values to something else.
A number of internal and public interfaces are changing as a result of
this commit, for example:
* Acessors on `wasmtime::Memory` that work with pages now all return
`u64` unconditionally rather than `u32`. This makes it possible to
accommodate 64-bit memories with this API, but we may also want to
consider `usize` here at some point since the host can't grow past
`usize`-limited pages anyway.
* The `wasmtime::Limits` structure is removed in favor of
minimum/maximum methods on table/memory types.
* Many libcall intrinsics called by jit code now unconditionally take
`u64` arguments instead of `u32`. Return values are `usize`, however,
since the return value, if successful, is always bounded by host
memory while arguments can come from any guest.
* The `heap_addr` clif instruction now takes a 64-bit offset argument
instead of a 32-bit one. It turns out that the legalization of
`heap_addr` already worked with 64-bit offsets, so this change was
fairly trivial to make.
* The runtime implementation of mmap-based linear memories has changed
to largely work in `usize` quantities in its API and in bytes instead
of pages. This simplifies various aspects and reflects that
mmap-memories are always bound by `usize` since that's what the host
is using to address things, and additionally most calculations care
about bytes rather than pages except for the very edge where we're
going to/from wasm.
Overall I've tried to minimize the amount of `as` casts as possible,
using checked `try_from` and checked arithemtic with either error
handling or explicit `unwrap()` calls to tell us about bugs in the
future. Most locations have relatively obvious things to do with various
implications on various hosts, and I think they should all be roughly of
the right shape but time will tell. I mostly relied on the compiler
complaining that various types weren't aligned to figure out
type-casting, and I manually audited some of the more obvious locations.
I suspect we have a number of hidden locations that will panic on 32-bit
hosts if 64-bit modules try to run there, but otherwise I think we
should be generally ok (famous last words). In any case I wouldn't want
to enable this by default naturally until we've fuzzed it for some time.
In terms of the actual underlying implementation, no one should expect
memory64 to be all that fast. Right now it's implemented with
"dynamic" heaps which have a few consequences:
* All memory accesses are bounds-checked. I'm not sure how aggressively
Cranelift tries to optimize out bounds checks, but I suspect not a ton
since we haven't stressed this much historically.
* Heaps are always precisely sized. This means that every call to
`memory.grow` will incur a `memcpy` of memory from the old heap to the
new. We probably want to at least look into `mremap` on Linux and
otherwise try to implement schemes where dynamic heaps have some
reserved pages to grow into to help amortize the cost of
`memory.grow`.
The memory64 spec test suite is scheduled to now run on CI, but as with
all the other spec test suites it's really not all that comprehensive.
I've tried adding more tests for basic things as I've had to implement
guards for them, but I wouldn't really consider the testing adequate
from just this PR itself. I did try to take care in one test to actually
allocate a 4gb+ heap and then avoid running that in the pooling
allocator or in emulation because otherwise that may fail or take
excessively long.
[proposal]: https://github.com/WebAssembly/memory64/blob/master/proposals/memory64/Overview.md
* Fix some tests
* More test fixes
* Fix wasmtime tests
* Fix doctests
* Revert to 32-bit immediate offsets in `heap_addr`
This commit updates the generation of addresses in wasm code to always
use 32-bit offsets for `heap_addr`, and if the calculated offset is
bigger than 32-bits we emit a manual add with an overflow check.
* Disable memory64 for spectest fuzzing
* Fix wrong offset being added to heap addr
* More comments!
* Clarify bytes/pages
* Bump the wasm-tools crates
Pulls in some updates here and there, mostly for updating crates to the
latest version to prepare for later memory64 work.
* Update lightbeam
This incorrectly assumed that we had unparsed dwarf information,
regardless of custom section name. This commit updates the logic to
calculate that by first checking the section name before we set the flag
indicating that there's unparsed debuginfo.
* Upgrade to the latest versions of gimli, addr2line, object
And adapt to API changes. New gimli supports wasm dwarf, resulting in
some simplifications in the debug crate.
* upgrade gimli usage in linux-specific profiling too
* Add "continue" statement after interpreting a wasm local dwarf opcode
Now that we're using "possibly exported" as an impactful decision for
codegen (which trampolines to generate and which ABI a function has)
it's important that we calculate this property of a wasm function
correctly! Previously Wasmtime forgot to processed "declared" elements
in apart from active/passive element segments, but this updates Wasmtime
to ensure that these entries are processed and all the functions
contained within are flagged as "possibly exported".
Closes#2850
* Optimize `table.init` instruction and instantiation
This commit optimizes table initialization as part of instance
instantiation and also applies the same optimization to the `table.init`
instruction. One part of this commit is to remove some preexisting
duplication between instance instantiation and the `table.init`
instruction itself, after this the actual implementation of `table.init`
is optimized to effectively have fewer bounds checks in fewer places and
have a much tighter loop for instantiation.
A big fallout from this change is that memory/table initializer offsets
are now stored as `u32` instead of `usize` to remove a few casts in a
few places. This ended up requiring moving some overflow checks that
happened in parsing to later in code itself because otherwise the wrong
spec test errors are emitted during testing. I've tried to trace where
these can possibly overflow but I think that I managed to get
everything.
In a local synthetic test where an empty module with a single 80,000
element initializer this improves total instantiation time by 4x (562us
=> 141us)
* Review comments
* Fully support multiple returns in Wasmtime
For quite some time now Wasmtime has "supported" multiple return values,
but only in the mose bare bones ways. Up until recently you couldn't get
a typed version of functions with multiple return values, and never have
you been able to use `Func::wrap` with functions that return multiple
values. Even recently where `Func::typed` can call functions that return
multiple values it uses a double-indirection by calling a trampoline
which calls the real function.
The underlying reason for this lack of support is that cranelift's ABI
for returning multiple values is not possible to write in Rust. For
example if a wasm function returns two `i32` values there is no Rust (or
C!) function you can write to correspond to that. This commit, however
fixes that.
This commit adds two new ABIs to Cranelift: `WasmtimeSystemV` and
`WasmtimeFastcall`. The intention is that these Wasmtime-specific ABIs
match their corresponding ABI (e.g. `SystemV` or `WindowsFastcall`) for
everything *except* how multiple values are returned. For multiple
return values we simply define our own version of the ABI which Wasmtime
implements, which is that for N return values the first is returned as
if the function only returned that and the latter N-1 return values are
returned via an out-ptr that's the last parameter to the function.
These custom ABIs provides the ability for Wasmtime to bind these in
Rust meaning that `Func::wrap` can now wrap functions that return
multiple values and `Func::typed` no longer uses trampolines when
calling functions that return multiple values. Although there's lots of
internal changes there's no actual changes in the API surface area of
Wasmtime, just a few more impls of more public traits which means that
more types are supported in more places!
Another change made with this PR is a consolidation of how the ABI of
each function in a wasm module is selected. The native `SystemV` ABI,
for example, is more efficient at returning multiple values than the
wasmtime version of the ABI (since more things are in more registers).
To continue to take advantage of this Wasmtime will now classify some
functions in a wasm module with the "fast" ABI. Only functions that are
not reachable externally from the module are classified with the fast
ABI (e.g. those not exported, used in tables, or used with `ref.func`).
This should enable purely internal functions of modules to have a faster
calling convention than those which might be exposed to Wasmtime itself.
Closes#1178
* Tweak some names and add docs
* "fix" lightbeam compile
* Fix TODO with dummy environ
* Unwind info is a property of the target, not the ABI
* Remove lightbeam unused imports
* Attempt to fix arm64
* Document new ABIs aren't stable
* Fix filetests to use the right target
* Don't always do 64-bit stores with cranelift
This was overwriting upper bits when 32-bit registers were being stored
into return values, so fix the code inline to do a sized store instead
of one-size-fits-all store.
* At least get tests passing on the old backend
* Fix a typo
* Add some filetests with mixed abi calls
* Get `multi` example working
* Fix doctests on old x86 backend
* Add a mixture of wasmtime/system_v tests
Currently wasmtime will generate a `SignatureIndex`-per-type in the
module itself, even if the module itself declares the same type multiple
times. To make matters worse if the same type is declared across
multiple modules used in a module-linking-using-module then the
signature will be recorded each time it's declared.
This commit adds a simple map to module translation to deduplicate these
function types. This should improve the performance of module-linking
graphs where the same function type may be declared in a number of
modules. For modules that don't use module linking this adds an extra
map that's not used too often, but the time spent managing it should be
dwarfed by other compile tasks.
* Add `anyhow` dependency to `wasmtime-runtime`.
* Revert `get_data` back to `fn`.
* Remove `DataInitializer` and box the data in `Module` translation instead.
* Improve comments on `MemoryInitialization`.
* Remove `MemoryInitialization::OutOfBounds` in favor of proper bulk memory
semantics.
* Use segmented memory initialization except for when the uffd feature is
enabled on Linux.
* Validate modules with the allocator after translation.
* Updated various functions in the runtime to return `anyhow::Result`.
* Use a slice when copying pages instead of `ptr::copy_nonoverlapping`.
* Remove unnecessary casts in `OnDemandAllocator::deallocate`.
* Better document the `uffd` feature.
* Use WebAssembly page-sized pages in the paged initialization.
* Remove the stack pool from the uffd handler and simply protect just the guard
pages.
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.
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.
This method attempted to reserve space in the `results` list of final
modules. Unfortunately `results.reserve(nmodules)` isn't enough here
because this can be called many times before a module is actually
finished and pushed onto the vector. The attempted logic to work around
this was buggy, however, and would simply trigger geometric growth on
every single reservation because it erroneously assumed that a
reservation would be exactly met.
This is fixed by avoiding looking at the vector's capacity and instead
keeping track of modules-to-be in a side field. This is the incremented
and passed to `reserve` as it represents the number of modules that will
eventually make their way into the result vector.
* 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
* Provide filename/line number information in `Trap`
This commit extends the `Trap` type and `Store` to retain DWARF debug
information found in a wasm file unconditionally, if it's present. This
then enables us to print filenames and line numbers which point back to
actual source code when a trap backtrace is printed. Additionally the
`FrameInfo` type has been souped up to return filename/line number
information as well.
The implementation here is pretty simplistic currently. The meat of all
the work happens in `gimli` and `addr2line`, and otherwise wasmtime is
just schlepping around bytes of dwarf debuginfo here and there!
The general goal here is to assist with debugging when using wasmtime
because filenames and line numbers are generally orders of magnitude
better even when you already have a stack trace. Another nicety here is
that backtraces will display inlined frames (learned through debug
information), improving the experience in release mode as well.
An example of this is that with this file:
```rust
fn main() {
panic!("hello");
}
```
we get this stack trace:
```
$ rustc foo.rs --target wasm32-wasi -g
$ cargo run foo.wasm
Finished dev [unoptimized + debuginfo] target(s) in 0.16s
Running `target/debug/wasmtime foo.wasm`
thread 'main' panicked at 'hello', foo.rs:2:5
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
Error: failed to run main module `foo.wasm`
Caused by:
0: failed to invoke command default
1: wasm trap: unreachable
wasm backtrace:
0: 0x6c1c - panic_abort::__rust_start_panic::abort::h2d60298621b1ccbf
at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/library/panic_abort/src/lib.rs:77:17
- __rust_start_panic
at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/library/panic_abort/src/lib.rs:32:5
1: 0x68c7 - rust_panic
at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/library/std/src/panicking.rs:626:9
2: 0x65a1 - std::panicking::rust_panic_with_hook::h2345fb0909b53e12
at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/library/std/src/panicking.rs:596:5
3: 0x1436 - std::panicking::begin_panic::{{closure}}::h106f151a6db8c8fb
at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/library/std/src/panicking.rs:506:9
4: 0xda8 - std::sys_common::backtrace::__rust_end_short_backtrace::he55aa13f22782798
at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/library/std/src/sys_common/backtrace.rs:153:18
5: 0x1324 - std::panicking::begin_panic::h1727e7d1d719c76f
at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/library/std/src/panicking.rs:505:12
6: 0xfde - foo::main::h2db1313a64510850
at /Users/acrichton/code/wasmtime/foo.rs:2:5
7: 0x11d5 - core::ops::function::FnOnce::call_once::h20ee1cc04aeff1fc
at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/library/core/src/ops/function.rs:227:5
8: 0xddf - std::sys_common::backtrace::__rust_begin_short_backtrace::h054493e41e27e69c
at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/library/std/src/sys_common/backtrace.rs:137:18
9: 0x1d5a - std::rt::lang_start::{{closure}}::hd83784448d3fcb42
at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/library/std/src/rt.rs:66:18
10: 0x69d8 - core::ops::function::impls::<impl core::ops::function::FnOnce<A> for &F>::call_once::h564d3dad35014917
at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/library/core/src/ops/function.rs:259:13
- std::panicking::try::do_call::hdca4832ace5a8603
at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/library/std/src/panicking.rs:381:40
- std::panicking::try::ha8624a1a6854b456
at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/library/std/src/panicking.rs:345:19
- std::panic::catch_unwind::h71421f57cf2bc688
at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/library/std/src/panic.rs:382:14
- std::rt::lang_start_internal::h260050c92cd470af
at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/library/std/src/rt.rs:51:25
11: 0x1d0c - std::rt::lang_start::h0b4bcf3c5e498224
at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/library/std/src/rt.rs:65:5
12: 0xffc - <unknown>!__original_main
13: 0x393 - __muloti4
at /cargo/registry/src/github.com-1ecc6299db9ec823/compiler_builtins-0.1.35/src/macros.rs:269
```
This is relatively noisy by default but there's filenames and line
numbers! Additionally frame 10 can be seen to have lots of frames
inlined into it. All information is always available to the embedder but
we could try to handle the `__rust_begin_short_backtrace` and
`__rust_end_short_backtrace` markers to trim the backtrace by default as
well.
The only gotcha here is that it looks like `__muloti4` is out of place.
That's because the libc that Rust ships with doesn't have dwarf
information, although I'm not sure why we land in that function for
symbolizing it...
* Add a configuration switch for debuginfo
* Control debuginfo by default with `WASM_BACKTRACE_DETAILS`
* Try cpp_demangle on demangling as well
* Rename to WASMTIME_BACKTRACE_DETAILS
This commit implements the interpretation necessary of the instance
section of the module linking proposal. Instantiating a module which
itself has nested instantiated instances will now instantiate the nested
instances properly. This isn't all that useful without the ability to
alias exports off the result, but we can at least observe the side
effects of instantiation through the `start` function.
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`.
* Validate modules while translating
This commit is a change to cranelift-wasm to validate each function body
as it is translated. Additionally top-level module translation functions
will perform module validation. This commit builds on changes in
wasmparser to perform module validation interwtwined with parsing and
translation. This will be necessary for future wasm features such as
module linking where the type behind a function index, for example, can
be far away in another module. Additionally this also brings a nice
benefit where parsing the binary only happens once (instead of having an
up-front serial validation step) and validation can happen in parallel
for each function.
Most of the changes in this commit are plumbing to make sure everything
lines up right. The major functional change here is that module
compilation should be faster by validating in parallel (or skipping
function validation entirely in the case of a cache hit). Otherwise from
a user-facing perspective nothing should be that different.
This commit does mean that cranelift's translation now inherently
validates the input wasm module. This means that the Spidermonkey
integration of cranelift-wasm will also be validating the function as
it's being translated with cranelift. The associated PR for wasmparser
(bytecodealliance/wasmparser#62) provides the necessary tools to create
a `FuncValidator` for Gecko, but this is something I'll want careful
review for before landing!
* Read function operators until EOF
This way we can let the validator take care of any issues with
mismatched `end` instructions and/or trailing operators/bytes.
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.
* Don't re-parse wasm for debuginfo
This commit updates debuginfo parsing to happen during the main
translation of the original wasm module. This avoid re-parsing the wasm
module twice (at least the section-level headers). Additionally this
ties debuginfo directly to a `ModuleTranslation` which makes it easier
to process debuginfo for nested modules in the upcoming module linking
proposal.
The changes here are summarized by taking the `read_debuginfo` function
and merging it with the main module translation that happens which is
driven by cranelift. Some new hooks were added to the module environment
trait to support this, but most of it was integrating with existing hooks.
* Fix tests in debug crate
`funcref`s are implemented as `NonNull<VMCallerCheckedAnyfunc>`.
This should be more efficient than using a `VMExternRef` that points at a
`VMCallerCheckedAnyfunc` because it gets rid of an indirection, dynamic
allocation, and some reference counting.
Note that the null function reference is *NOT* a null pointer; it is a
`VMCallerCheckedAnyfunc` that has a null `func_ptr` member.
Part of #929
For host VM code, we use plain reference counting, where cloning increments
the reference count, and dropping decrements it. We can avoid many of the
on-stack increment/decrement operations that typically plague the
performance of reference counting via Rust's ownership and borrowing system.
Moving a `VMExternRef` avoids mutating its reference count, and borrowing it
either avoids the reference count increment or delays it until if/when the
`VMExternRef` is cloned.
When passing a `VMExternRef` into compiled Wasm code, we don't want to do
reference count mutations for every compiled `local.{get,set}`, nor for
every function call. Therefore, we use a variation of **deferred reference
counting**, where we only mutate reference counts when storing
`VMExternRef`s somewhere that outlives the activation: into a global or
table. Simultaneously, we over-approximate the set of `VMExternRef`s that
are inside Wasm function activations. Periodically, we walk the stack at GC
safe points, and use stack map information to precisely identify the set of
`VMExternRef`s inside Wasm activations. Then we take the difference between
this precise set and our over-approximation, and decrement the reference
count for each of the `VMExternRef`s that are in our over-approximation but
not in the precise set. Finally, the over-approximation is replaced with the
precise set.
The `VMExternRefActivationsTable` implements the over-approximized set of
`VMExternRef`s referenced by Wasm activations. Calling a Wasm function and
passing it a `VMExternRef` moves the `VMExternRef` into the table, and the
compiled Wasm function logically "borrows" the `VMExternRef` from the
table. Similarly, `global.get` and `table.get` operations clone the gotten
`VMExternRef` into the `VMExternRefActivationsTable` and then "borrow" the
reference out of the table.
When a `VMExternRef` is returned to host code from a Wasm function, the host
increments the reference count (because the reference is logically
"borrowed" from the `VMExternRefActivationsTable` and the reference count
from the table will be dropped at the next GC).
For more general information on deferred reference counting, see *An
Examination of Deferred Reference Counting and Cycle Detection* by Quinane:
https://openresearch-repository.anu.edu.au/bitstream/1885/42030/2/hon-thesis.pdf
cc #929Fixes#1804
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.
In the `ModuleEnvironment::declare_signature` callback, also pass the original
Wasm function signature, so that consumers may associate this information with
each compiled function. This is often necessary because while each Wasm
signature gets compiled down into a single native signature, multiple Wasm
signatures might compile down into the same native signature, and in these cases
the original Wasm signature is required for dynamic type checking of calls.
* 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.
* wasmtime: Pass around more contexts instead of fields
This commit refactors some wasmtime internals to pass around more
context-style structures rather than individual fields of each
structure. The intention here is to make the addition of fields to a
structure easier to plumb throughout the internals of wasmtime.
Currently you need to edit lots of functions to pass lots of parameters,
but ideally after this you'll only need to edit one or two struct fields
and then relevant locations have access to the information already.
Updates in this commit are:
* `debug_info` configuration is now folded into `Tunables`. Additionally
a `wasmtime::Config` now holds a `Tunables` directly and is passed
into an internal `Compiler`. Eventually this should allow for direct
configuration of the `Tunables` attributes from the `wasmtime` API,
but no new configuration is exposed at this time.
* `ModuleTranslation` is now passed around as a whole rather than
passing individual components to allow access to all the fields,
including `Tunables`.
This was motivated by investigating what it would take to optionally
allow loops and such to get interrupted, but that sort of codegen
setting was currently relatively difficult to plumb all the way through
and now it's hoped to be largely just an addition to `Tunables`.
* Fix lightbeam compile
* 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
