Integrate Lightbeam with latest Wasmtime master (#1232)

* Implement trap info in Lightbeam

* Start using wasm-reader instead of wasmparser for parsing operators

* Update to use wasm-reader, some reductions in allocation, support source location tracking for traps, start to support multi-value

The only thing that still needs to be supported for multi-value is stack returns, but we need to make it compatible with Cranelift.

* Error when running out of registers (although we'd hope it should be impossible) instead of panicking

* WIP: Update Lightbeam to work with latest Wasmtime

* WIP: Update Lightbeam to use current wasmtime

* WIP: Migrate to new system for builtin functions

* WIP: Update Lightbeam to work with latest Wasmtime

* Remove multi_mut

* Format

* Fix some bugs around arguments, add debuginfo offset tracking

* Complete integration with new Wasmtime

* Remove commented code

* Fix formatting

* Fix warnings, remove unused dependencies

* Fix `iter` if there are too many elements, fix compilation for latest wasmtime

* Fix float arguments on stack

* Remove wasm-reader and trap info work

* Allocate stack space _before_ passing arguments, fail if we can't zero a xmm reg

* Fix stack argument offset calculation

* Fix stack arguments in Lightbeam

* Re-add WASI because it somehow got removed during rebase

* Workaround for apparent `type_alias_impl_trait`-related bug in rustdoc

* Fix breakages caused by rebase, remove module offset info as it is unrelated to wasmtime integration PR and was broken by rebase

* Add TODO comment explaining `lightbeam::ModuleContext` trait

crates/lightbeam/Cargo.toml

@@ -11,19 +11,20 @@ keywords = ["webassembly", "wasm", "compile", "compiler", "jit"]
 edition = "2018"
 
 [dependencies]
-smallvec = "1.0.0"
+capstone = "0.6.0"
+cranelift-codegen = { path = "../../cranelift/codegen", version = "0.62.0" }
+derive_more = "0.99"
 dynasm = "0.5.2"
 dynasmrt = "0.5.2"
-wasmparser = "0.51.2"
-memoffset = "0.5.3"
+iter-enum = "0.2"
 itertools = "0.8.2"
-capstone = "0.6.0"
-thiserror = "1.0.9"
-cranelift-codegen = { path = "../../cranelift/codegen", version = "0.62.0" }
-multi_mut = "0.1"
-either = "1.5"
-typemap = "0.3"
+memoffset = "0.5.3"
 more-asserts = "0.2.1"
+smallvec = "1.0.0"
+staticvec = "0.8"
+thiserror = "1.0.9"
+typemap = "0.3"
+wasmparser = "0.51.2"
 
 [dev-dependencies]
 lazy_static = "1.2"

crates/lightbeam/src/disassemble.rs

@@ -3,9 +3,9 @@ use dynasmrt::AssemblyOffset;
 use std::error::Error;
 use std::fmt::{Display, Write};
 
-pub fn disassemble(
+pub fn disassemble<D: Display>(
     mem: &[u8],
-    mut ops: &[(AssemblyOffset, impl Display)],
+    mut ops: &[(AssemblyOffset, D)],
 ) -> Result<(), Box<dyn Error>> {
     let cs = Capstone::new()
         .x86()

crates/lightbeam/src/lib.rs

@@ -8,7 +8,7 @@ mod backend;
 mod disassemble;
 mod error;
 mod function_body;
-mod microwasm;
+pub mod microwasm;
 mod module;
 mod translate_sections;
 
@@ -16,7 +16,10 @@ mod translate_sections;
 mod benches;
 
 pub use crate::backend::CodeGenSession;
-pub use crate::function_body::translate_wasm as translate_function;
+pub use crate::function_body::{
+    translate_wasm as translate_function, NullOffsetSink, OffsetSink, Sinks,
+};
 pub use crate::module::{
     translate, ExecutableModule, ExecutionError, ModuleContext, Signature, TranslatedModule,
 };
+pub use disassemble::disassemble;

crates/lightbeam/src/module.rs

@@ -300,8 +300,9 @@ impl Signature for CraneliftSignature {
         // TODO: We want to instead add the `VMContext` to the signature used by
         //       cranelift, removing the special-casing from the internals.
         assert_eq!(self.params[0].purpose, ir::ArgumentPurpose::VMContext);
+        // `self.params[1]` should be caller vmctx
         assert_eq!(self.call_conv, isa::CallConv::SystemV);
-        &self.params[1..]
+        &self.params[2..]
     }
 
     fn returns(&self) -> &[Self::Type] {
@@ -332,6 +333,7 @@ pub trait ModuleContext {
     type Signature: Signature;
     type GlobalType: SigType;
 
+    fn vmctx_builtin_function(&self, index: u32) -> u32;
     fn vmctx_vmglobal_definition(&self, index: u32) -> u32;
     fn vmctx_vmglobal_import_from(&self, index: u32) -> u32;
     fn vmctx_vmmemory_import_from(&self, memory_index: u32) -> u32;
@@ -424,6 +426,10 @@ impl ModuleContext for SimpleContext {
         Some(index)
     }
 
+    fn vmctx_builtin_function(&self, _index: u32) -> u32 {
+        unimplemented!()
+    }
+
     fn vmctx_vmfunction_import_body(&self, _func_index: u32) -> u32 {
         unimplemented!()
     }

crates/lightbeam/src/translate_sections.rs

@@ -1,6 +1,5 @@
-use crate::backend::{CodeGenSession, TranslatedCodeSection};
+use crate::backend::TranslatedCodeSection;
 use crate::error::Error;
-use crate::function_body;
 use crate::module::SimpleContext;
 use cranelift_codegen::{binemit, ir};
 use wasmparser::{
@@ -106,20 +105,13 @@ impl binemit::RelocSink for UnimplementedRelocSink {
 
 /// Parses the Code section of the wasm module.
 pub fn code(
-    code: CodeSectionReader,
-    translation_ctx: &SimpleContext,
+    _code: CodeSectionReader,
+    _translation_ctx: &SimpleContext,
 ) -> Result<TranslatedCodeSection, Error> {
-    let func_count = code.get_count();
-    let mut session = CodeGenSession::new(func_count, translation_ctx);
-
-    for (idx, body) in code.into_iter().enumerate() {
-        let body = body?;
-        let mut relocs = UnimplementedRelocSink;
-
-        function_body::translate_wasm(&mut session, &mut relocs, idx as u32, &body)?;
-    }
-
-    Ok(session.into_translated_code_section()?)
+    // TODO: Remove the Lightbeam harness entirely, this is just to make this compile.
+    //       We do all our testing through Wasmtime now, there's no reason to duplicate
+    //       writing a WebAssembly environment in Lightbeam too.
+    unimplemented!("Incomplete migration to wasm-reader");
 }
 
 /// Parses the Data section of the wasm module.