wasmparser: feature gate Wasm simd support (#1903)

* add for_each_simd_operator generator macro

* define SimdOperator enum

* add SimdOperator::operator_arity impl

* add VisitSimdOperator trait definition

* define VisitSimdOperator delegates

* add benchmark NopVisit impl

* add simd crate feature

* add simd_visitor method to VisitOperator trait

* add VisitSimdOperator impl to OperatorFactory

* use VisitOperator::simd_visitor in BinaryReader::visit_operator

* add lifetime to return value of simd_visitor method

* add VisitSimdOperator impl for OperatorValidator

* add Operator::Simd variant

* remove simd operators from for_each_operator macro

* adjust wasmprinter crate for simd crate feature

* enable wasmparser's simd feature by default

* fix trait impl signature

* add docs to wasmparser's simd crate feature

* feature gate simd related code in wasmparser

* update docs for SimdOperator

* add missing `simd` crate feature gates

* move simd op validation down in file

* put simd specific operator validation in separate file

* add docs to for_each_simd_operator macro

* move for_each_simd_operator macro into a separate file

* fix docs for VisitSimdOperator

* allow missing docs again for VisitSimdOperator

This is just like with VisitOperator trait.

* add docs and example to VisitOperator::simd_visitor

* move visit_0xfd_operator into separate file

We do this to further improve compile times for when the `simd` crate feature is disabled.

* apply rustftm

* wasmprinter: fix remaining simd feature toggles

* apply rustfmt

* fix wasmparser benchmarks

* wasm-encoder: add simd support

* apply rustfmt and avoid formatting some parts

* wasm-mutate: fix compile errors

* apply rustfmt

* fix dev-dependencies for wasm-mutate

* add simd_visitor impl to NopVisitor

* add missing VisitSimdOperator impl for WasmProposalValidator

* mark doc example as compile_fail

* add simd support for VisitConstOperator

* use wasmparser/simd in validate tool

* add simd crate feature propagation to wasm-tools CLI tool

* wasm-smith: use wasmparser/simd crate feature

* apply rustfmt

* feature gate simd_visitor impl

* unconditionally enable simd for wasmprinter

* unconditionally enable simd for wasm-encoder

* remove wasm-tools simd feature (enable by default)

* use macros generate for_each_operator macros

- This does not yet provide a for_each_operator macro in for !simd mode but that should be easily added.
- This is WIP in that is currently does not handle the documentation of the macros well. We might need to also generate the macro docs in the macros themselves.

* remove comment out line

* put docs on the exported macros

* fix macro imports

* fix bugs in generator macros

* improve compile times for macros

* group macro operators together

* restructure for_each_operator macros

This improves compile times performance significantly.

* apply rustfmt

* re-structure the new exposed macros

The wasmparser crate now exposes 3 different for_each macros:

- for_each_operator: Same as before the PR. Iterates over _all_ operators. This is going to be used to implement a routine for all Operator enum variants.
- for_each_visit_oeprator: This is going to be used to implement the `VisitOperator` trait.
- for_each_visit_simd_operator: This is going to be used to implement the `VisitSimdOperator` trait.

* fix macro doc links

* fix broken doc links

* fix crate after making Operator enum inline

* export all internal macro (debug)

* wasmprinter: use for_each_[visit[_simd]]_operator

* wasm-encoder: use simd feature in dependencies

* fix wasm-encoder compilation

* wasmparser: use macros via crate:: namespace

* expose macros via use statements

* use doc(inline)

* use intra-doc links

* wit-component: fix wasmparser usage

* wasm-mutate: fix wasmparser usage

This mostly reverts the changes done in past commits of the PR.

* wasm-dump: fix wasmparser usage

* wasmparser: fix benchmarks

* fix doc tests

* change doc example for for_each_operator macro

* rename doc test macro

* fix typo

* apply rustfmt

* craft new doc example for for_each_operator! macro

* Minor changes

* Revert `crates/wasm-encoder/src/reencode.rs` back to `main` version
  (no changes needed any more)
* Minor whitespace/style changes
* Document the macros some more in `wasmparser/src/lib.rs`
* Reorganize macro-defining-macros to have more predictable names.

* A few more minor adjustments

---------

Co-authored-by: Alex Crichton <[email protected]>

Cargo.toml

@@ -102,7 +102,7 @@ wasm-metadata = { version = "0.220.0", path = "crates/wasm-metadata" }
 wasm-mutate = { version = "0.220.0", path = "crates/wasm-mutate" }
 wasm-shrink = { version = "0.220.0", path = "crates/wasm-shrink" }
 wasm-smith = { version = "0.220.0", path = "crates/wasm-smith" }
-wasmparser = { version = "0.220.0", path = "crates/wasmparser", default-features = false, features = ['std'] }
+wasmparser = { version = "0.220.0", path = "crates/wasmparser", default-features = false, features = ['std','simd'] }
 wasmprinter = { version = "0.220.0", path = "crates/wasmprinter", default-features = false }
 wast = { version = "220.0.0", path = "crates/wast", default-features = false }
 wat = { version = "1.220.0", path = "crates/wat", default-features = false }
@@ -122,7 +122,7 @@ wat = { workspace = true, features = ['dwarf', 'component-model'] }
 termcolor = { workspace = true }
 
 # Dependencies of `validate`
-wasmparser = { workspace = true, optional = true, features = ['component-model'] }
+wasmparser = { workspace = true, optional = true, features = ['component-model', 'simd'] }
 rayon = { workspace = true, optional = true }
 bitflags = { workspace = true, optional = true }
 

crates/wasm-encoder/Cargo.toml

@@ -24,7 +24,7 @@ leb128 = { workspace = true }
 
 # Enable this dependency to get a bunch of `From<wasmparser::Foo> for
 # wasm_encoder::Foo` impls.
-wasmparser = { optional = true, workspace = true }
+wasmparser = { optional = true, workspace = true, features = ["simd"] }
 
 [dev-dependencies]
 anyhow = { workspace = true }

crates/wasm-encoder/src/reencode.rs

@@ -1563,6 +1563,7 @@ pub mod utils {
                             translate!(build $op $($($arg)*)?)
                         }
                     )*
+                    unexpected => unreachable!("encountered unexpected Wasm operator: {unexpected:?}"),
                 })
             };
 

crates/wasm-mutate/Cargo.toml

@@ -13,8 +13,8 @@ workspace = true
 [dependencies]
 clap = { workspace = true, optional = true }
 thiserror = "1.0.28"
-wasmparser = { workspace = true }
-wasm-encoder = { workspace = true, features = ["wasmparser"] }
+wasmparser = { workspace = true, features = ['simd'] }
+wasm-encoder = { workspace = true, features = ['wasmparser'] }
 rand = { workspace = true }
 log = { workspace = true }
 egg = "0.6.0"
@@ -24,4 +24,4 @@ anyhow = { workspace = true }
 wat = { workspace = true }
 wasmprinter = { workspace = true }
 env_logger = { workspace = true }
-wasmparser = { workspace = true, features = ['validate', 'features'] }
+wasmparser = { workspace = true, features = ['validate', 'features', 'simd'] }

crates/wasm-smith/Cargo.toml

@@ -32,13 +32,13 @@ leb128 = { workspace = true }
 serde = { workspace = true, optional = true }
 serde_derive = { workspace = true, optional = true }
 wasm-encoder = { workspace = true }
-wasmparser = { workspace = true, optional = true, features = ['validate', 'features'] }
+wasmparser = { workspace = true, optional = true, features = ['validate', 'features', 'simd'] }
 wat = { workspace = true, optional = true }
 
 [dev-dependencies]
 criterion = { workspace = true }
 rand = { workspace = true }
-wasmparser = { workspace = true, features = ["validate", "features"] }
+wasmparser = { workspace = true, features = ['validate', 'features', 'simd'] }
 wasmprinter = { workspace = true }
 wat = { workspace = true }
 

crates/wasmparser/Cargo.toml

@@ -42,7 +42,7 @@ name = "benchmark"
 harness = false
 
 [features]
-default = ['std', 'validate', 'serde', 'features', 'component-model', 'hash-collections']
+default = ['std', 'validate', 'serde', 'features', 'component-model', 'hash-collections', 'simd']
 
 # A feature which enables implementations of `std::error::Error` as appropriate
 # along with other convenience APIs. This additionally uses the standard
@@ -82,3 +82,8 @@ features = []
 # WebAssembly. This is enabled by default but if your use case is only
 # interested in working with core modules then this feature can be disabled.
 component-model = ['dep:semver']
+
+# A feature that enables parsing and validating the `simd` and `relaxed-simd`
+# proposals for WebAssembly. This is enabled by default but if your use case is
+# only interested in working on non-SIMD code then this feature can be disabled.
+simd = []

crates/wasmparser/benches/benchmark.rs

@@ -4,6 +4,7 @@ use once_cell::unsync::Lazy;
 use std::fs;
 use std::path::Path;
 use std::path::PathBuf;
+use wasmparser::VisitSimdOperator;
 use wasmparser::{DataKind, ElementKind, Parser, Payload, Validator, VisitOperator, WasmFeatures};
 
 /// A benchmark input.
@@ -364,5 +365,14 @@ macro_rules! define_visit_operator {
 impl<'a> VisitOperator<'a> for NopVisit {
     type Output = ();
 
-    wasmparser::for_each_operator!(define_visit_operator);
+    fn simd_visitor(&mut self) -> Option<&mut dyn VisitSimdOperator<'a, Output = Self::Output>> {
+        Some(self)
+    }
+
+    wasmparser::for_each_visit_operator!(define_visit_operator);
+}
+
+#[allow(unused_variables)]
+impl<'a> VisitSimdOperator<'a> for NopVisit {
+    wasmparser::for_each_visit_simd_operator!(define_visit_operator);
 }

crates/wasmparser/src/arity.rs

@@ -253,6 +253,6 @@ impl Operator<'_> {
                 }
             );
         }
-        for_each_operator!(define_arity)
+        crate::for_each_operator!(define_arity)
     }
 }