This latest refactor adds "extractor macros" in place of the
very-confusing-even-to-the-DSL-author reverse-rules-as-extractors
concept. It was beautifully symmetric but also just too mind-bending to
be practical.
It also adds argument polarity to external extractors. This is inspired
by Prolog's similar notion (see e.g. the "+x" vs. "-x" argument notation
in library documentation) where the unification-based semantics allow
for bidirectional flow through arguments. We don't want polymorphism
or dynamism w.r.t. directions/polarities here; the polarities are
static; but it is useful to be able to feed values *into* an extractor
(aside from the one value being extracted). Semantically this still
correlates to a term-rewriting/value-equivalence world since we can
still translate all of this to a list of equality constraints.
To make that work, this change also adds expressions into patterns,
specifically only for extractor "input" args. This required quite a bit
of internal refactoring but is only a small addition to the language
semantics.
I plan to build out the little instruction-selector sketch further but
the one that is here (in `test3.isle`) is starting to get interesting
already with the current DSL semantics.
See long block comment in codegen.rs. In brief, I think we actually want
to compile to a trie with priority-intervals, a sort of hybrid of a
priority tree and a trie representing decisions keyed on match-ops
(PatternInsts).
The reasons are:
1. The lexicographic ordering that is fundamental to the FSM-building in
the Peepmatic view of the problem is sort of fundamentally limited
w.r.t. our notion of rule priorities. See the example in the block
comment.
2. While the FSM is nice for interpreter-based execution, when compiling
to a language with structured control flow, what we really want is a
tree; otherwise, if we want to form DAGs to share substructure, we
need something like a "diamond-recovery" algorithm that finds common
suffixes of *input match-op sequences*, and then we need to
incorporate something like phi-nodes in order to allow captures from
either side of the diamond to be used.
3. One of the main advantages of the automaton/transducer approach,
namely sharing suffixes of the *output* sequence (emitting partial
output at each state transition), is unfortunately not applicable if
we allow the overall function to be partial. Otherwise, there is
always the possibility that we fail at the last match op, so we
cannot allow any external constructors to be called until we reach
the final state anyway.
4. Pragmatically, I found I was having to significantly edit the
peepmatic_automata implementation to adapt to this use-case
(compilation to Rust), and it seemed more practical to design the
data structure we want than to try to shoehorn the existing thing
into the new problem.
WIP, hopefully working soon.
This commit adds the `pooling-allocator` feature to both the `wasmtime` and
`wasmtime-runtime` crates.
The feature controls whether or not the pooling allocator implementation is
built into the runtime and exposed as a supported instance allocation strategy
in the wasmtime API.
The feature is on by default for the `wasmtime` crate.
Closes#3513.
* Change the bump-version workflow's schedule
Either I don't understand cron or GitHub doesn't understand cron. It's
not clear which. I think that
https://github.com/bytecodealliance/wasmtime/pull/3511 may have fallen
within our schedule but it was supposed to be on a weekday. Otherwise
https://github.com/bytecodealliance/wasmtime/pull/3499 was certainly
spurious. This commit moves to a simpler "just do it on the same day
each month" and we can manually figure out weekdays and such. Hopefully
this should reduce the number of spurious PRs we're getting to bump
versions.
This also removes the script to force a version bump since I found a
button on the GitHub UI to do the same thing. Additionally I've updated
the patch-release documentation to use this button. Note that this
button takes inputs as well which means we can further automate patch
releases to look even more like normal release process, differing only
in one part of the argument used to trigger the workflow.
* Fix a typo
When encountering a subprogram that is dead code (as indicated by the
dead code proposal
https://dwarfstd.org/ShowIssue.php?issue=200609.1), don't generate debug
output for the subprogram or any of its children.
Its a manually written impl, not a derive, because InstancePre<T>: Clone
does not require T: Clone.
The clone should be reasonably inexpensive: Clone for Module is just an
Arc, and Clone for Definition should also just be an Arc on the HostFunc
or Instance variants. An InstancePre shouldnt contain any
Definition::Extern variants because there is not yet a Store associated
with it- right?
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.
* Add a configuration option to force "static" memories
In poking around at some things earlier today I realized that one
configuration option for memories we haven't exposed from embeddings
like the CLI is to forcibly limit the size of memory growth and force
using a static memory style. This means that the CLI, for example, can't
limit memory growth by default and memories are only limited in size by
what the OS can give and the wasm's own memory type. This configuration
option means that the CLI can artificially limit the size of wasm linear
memories.
Additionally another motivation for this is for testing out various
codegen ramifications of static/dynamic memories. This is the only way
to force a static memory, by default, for wasm64 memories with no
maximum size listed for example.
* Review feedback
This opcode was removed as part of the old-backend cleanup in #3446.
While this opcode will definitely go away eventually, it is
unfortunately still used today in Lucet (as we just discovered while
working to upgrade Lucet's pinned Cranelift version). Lucet is
deprecated and slated to eventually be completely sunset in favor of
Wasmtime; but until that happens, we need to keep this opcode.
