Merge branch 'master' into wasi-common

.github/workflows/main.yml

@@ -70,19 +70,19 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        build: [stable, beta, nightly, windows, linux]
+        build: [stable, beta, nightly, windows, macos]
         include:
           - build: stable
-            os: macos-latest
+            os: ubuntu-latest
             rust: stable
           - build: beta
-            os: macos-latest
+            os: ubuntu-latest
             rust: beta
           - build: nightly
-            os: macos-latest
-            rust: nightly
-          - build: linux
             os: ubuntu-latest
+            rust: nightly
+          - build: macos
+            os: macos-latest
             rust: stable
           - build: windows
             os: windows-latest
@@ -216,7 +216,7 @@ jobs:
     - run: $CENTOS cargo build --release --bin wasmtime --bin wasm2obj
       shell: bash
     # Build `libwasmtime_api.so`
-    - run: $CENTOS cargo build --release --features wasm-c-api --manifest-path wasmtime-api/Cargo.toml
+    - run: $CENTOS cargo build --release --manifest-path wasmtime-api/Cargo.toml
       shell: bash
     # Test what we just built
     - run: $CENTOS cargo test --features wasi-common/wasm_tests --release --all --exclude lightbeam --exclude wasmtime-wasi-c --exclude wasmtime-py --exclude wasmtime-api

Cargo.toml

@@ -38,9 +38,8 @@ libc = "0.2.60"
 rayon = "1.1"
 wasm-webidl-bindings = "0.6"
 
-# build.rs tests whether to enable a workaround for the libc strtof function.
+[build-dependencies]
-[target.'cfg(target_os = "linux")'.build-dependencies]
+anyhow = "1.0.19"
-libc = "0.2.60"
 
 [workspace]
 members = [

README.md

@@ -35,34 +35,24 @@ of ongoing research.
 Additional goals for Wasmtime include:
  - Support a variety of host APIs (not just WASI), with fast calling sequences,
    and develop proposals for additional API modules to be part of WASI.
- - Implement the [proposed WebAssembly C API].
+ - Facilitate development and testing around the [Cranelift] and [Lightbeam] JITs,
- - Facilitate testing, experimentation, and development around the [Cranelift] and
+   and other WebAssembly execution strategies.
-   [Lightbeam] JITs.
  - Develop a native ABI used for compiling WebAssembly suitable for use in both
    JIT and AOT to native object files.
 
-[proposed WebAssembly C API]: https://github.com/rossberg/wasm-c-api
 [Cranelift]: https://github.com/CraneStation/cranelift
-[Lightbeam]: https://github.com/CraneStation/lightbeam
+[Lightbeam]: https://github.com/CraneStation/wasmtime/tree/master/lightbeam
 
 #### Including Wasmtime in your project
-Wasmtime exposes an API for JIT compilation through the `wasmtime-jit` subcrate, which depends on `wasmtime-environ` and `wasmtime-runtime` for the ABI and runtime support respectively. However, this API is not documented and subject to change. Please use at your own risk!
 
-Build the individual crates as such:
+Wasmtime exposes an API for embedding as a library through the `wasmtime-api` subcrate,
+which contains both a [high-level and safe Rust API], as well as a C-compatible API
+compatible with the [proposed WebAssembly C API].
 
-```
+For more information, see the [Rust API embedding chapter] of the Wasmtime documentation.
-cargo build --package wasmtime-jit
-```
 
-Wasmtime does not currently publish these crates on crates.io. They may be included as a git dependency, like this:
+[high-level and safe Rust API]: https://docs.rs/wasmtime-api/
-
+[proposed WebAssembly C API]: https://github.com/WebAssembly/wasm-c-api
-```toml
+[Rust API embedding chapter]: https://cranestation.github.io/wasmtime/embed-rust.html
-[dependencies]
-wasmtime-environ = { git = "https://github.com/CraneStation/wasmtime", rev = "somecommithash" }
-wasmtime-runtime = { git = "https://github.com/CraneStation/wasmtime", rev = "somecommithash" }
-wasmtime-jit = { git = "https://github.com/CraneStation/wasmtime", rev = "somecommithash" }
-```
-
-All three crates must be specified as dependencies for `wasmtime-jit` to build correctly, at the moment.
 
 It's Wasmtime.

build.rs

@@ -3,108 +3,105 @@
 //! By generating a separate `#[test]` test for each file, we allow cargo test
 //! to automatically run the files in parallel.
 
+use anyhow::Context;
 use std::env;
-use std::fs::{read_dir, File};
+use std::fmt::Write;
-use std::io::{self, Write};
+use std::fs;
 use std::path::{Path, PathBuf};
+use std::process::Command;
 
-fn main() {
+fn main() -> anyhow::Result<()> {
-    let out_dir =
+    let out_dir = PathBuf::from(
-        PathBuf::from(env::var("OUT_DIR").expect("The OUT_DIR environment variable must be set"));
+        env::var_os("OUT_DIR").expect("The OUT_DIR environment variable must be set"),
-    let mut out = File::create(out_dir.join("wast_testsuite_tests.rs"))
+    );
-        .expect("error generating test source file");
+    let mut out = String::new();
 
     for strategy in &[
         "Cranelift",
         #[cfg(feature = "lightbeam")]
         "Lightbeam",
     ] {
-        writeln!(out, "#[cfg(test)]").expect("generating tests");
+        writeln!(out, "#[cfg(test)]")?;
-        writeln!(out, "#[allow(non_snake_case)]").expect("generating tests");
+        writeln!(out, "#[allow(non_snake_case)]")?;
-        writeln!(out, "mod {} {{", strategy).expect("generating tests");
+        writeln!(out, "mod {} {{", strategy)?;
 
-        test_directory(&mut out, "misc_testsuite", strategy).expect("generating tests");
+        test_directory(&mut out, "misc_testsuite", strategy)?;
-        test_directory(&mut out, "spec_testsuite", strategy).expect("generating tests");
+        let spec_tests = test_directory(&mut out, "spec_testsuite", strategy)?;
-        // Skip running spec_testsuite tests if the submodule isn't checked out.
+        // Skip running spec_testsuite tests if the submodule isn't checked
-        if read_dir("spec_testsuite")
+        // out.
-            .expect("reading testsuite directory")
+        if spec_tests > 0 {
-            .next()
+            start_test_module(&mut out, "simd")?;
-            .is_some()
+            write_testsuite_tests(
-        {
-            test_file(
                 &mut out,
-                &to_os_path(&["spec_testsuite", "proposals", "simd", "simd_address.wast"]),
+                "spec_testsuite/proposals/simd/simd_address.wast",
+                "simd",
                 strategy,
-            )
+            )?;
-            .expect("generating tests");
+            write_testsuite_tests(
-            test_file(
                 &mut out,
-                &to_os_path(&["spec_testsuite", "proposals", "simd", "simd_align.wast"]),
+                "spec_testsuite/proposals/simd/simd_align.wast",
+                "simd",
                 strategy,
-            )
+            )?;
-            .expect("generating tests");
+            write_testsuite_tests(
-            test_file(
                 &mut out,
-                &to_os_path(&["spec_testsuite", "proposals", "simd", "simd_const.wast"]),
+                "spec_testsuite/proposals/simd/simd_const.wast",
+                "simd",
                 strategy,
-            )
+            )?;
-            .expect("generating tests");
+            finish_test_module(&mut out)?;
 
-            let multi_value_suite = &to_os_path(&["spec_testsuite", "proposals", "multi-value"]);
+            test_directory(&mut out, "spec_testsuite/proposals/multi-value", strategy)
-            test_directory(&mut out, &multi_value_suite, strategy).expect("generating tests");
+                .expect("generating tests");
         } else {
             println!("cargo:warning=The spec testsuite is disabled. To enable, run `git submodule update --remote`.");
         }
 
-        writeln!(out, "}}").expect("generating tests");
+        writeln!(out, "}}")?;
     }
+
+    // Write out our auto-generated tests and opportunistically format them with
+    // `rustfmt` if it's installed.
+    let output = out_dir.join("wast_testsuite_tests.rs");
+    fs::write(&output, out)?;
+    drop(Command::new("rustfmt").arg(&output).status());
+    Ok(())
 }
 
-/// Helper for creating OS-independent paths.
+fn test_directory(
-fn to_os_path(components: &[&str]) -> String {
+    out: &mut String,
-    let path: PathBuf = components.iter().collect();
+    path: impl AsRef<Path>,
-    path.display().to_string()
+    strategy: &str,
-}
+) -> anyhow::Result<usize> {
-
+    let path = path.as_ref();
-fn test_directory(out: &mut File, path: &str, strategy: &str) -> io::Result<()> {
+    let mut dir_entries: Vec<_> = path
-    let mut dir_entries: Vec<_> = read_dir(path)
+        .read_dir()
-        .expect("reading testsuite directory")
+        .context(format!("failed to read {:?}", path))?
         .map(|r| r.expect("reading testsuite directory entry"))
-        .filter(|dir_entry| {
+        .filter_map(|dir_entry| {
             let p = dir_entry.path();
-            if let Some(ext) = p.extension() {
+            let ext = p.extension()?;
             // Only look at wast files.
-                if ext == "wast" {
+            if ext != "wast" {
+                return None;
+            }
             // Ignore files starting with `.`, which could be editor temporary files
-                    if let Some(stem) = p.file_stem() {
+            if p.file_stem()?.to_str()?.starts_with(".") {
-                        if let Some(stemstr) = stem.to_str() {
+                return None;
-                            if !stemstr.starts_with('.') {
-                                return true;
             }
-                        }
+            Some(p)
-                    }
-                }
-            }
-            false
         })
         .collect();
 
-    dir_entries.sort_by_key(|dir| dir.path());
+    dir_entries.sort();
 
     let testsuite = &extract_name(path);
     start_test_module(out, testsuite)?;
-    for dir_entry in dir_entries {
+    for entry in dir_entries.iter() {
-        write_testsuite_tests(out, &dir_entry.path(), testsuite, strategy)?;
+        write_testsuite_tests(out, entry, testsuite, strategy)?;
     }
-    finish_test_module(out)
+    finish_test_module(out)?;
-}
+    Ok(dir_entries.len())
-
-fn test_file(out: &mut File, testfile: &str, strategy: &str) -> io::Result<()> {
-    let path = Path::new(testfile);
-    let testsuite = format!("single_test_{}", extract_name(path));
-    start_test_module(out, &testsuite)?;
-    write_testsuite_tests(out, path, &testsuite, strategy)?;
-    finish_test_module(out)
 }
 
 /// Extract a valid Rust identifier from the stem of a path.
@@ -118,63 +115,38 @@ fn extract_name(path: impl AsRef<Path>) -> String {
         .replace("/", "_")
 }
 
-fn start_test_module(out: &mut File, testsuite: &str) -> io::Result<()> {
+fn start_test_module(out: &mut String, testsuite: &str) -> anyhow::Result<()> {
-    writeln!(out, "    mod {} {{", testsuite)?;
+    writeln!(out, "mod {} {{", testsuite)?;
-    writeln!(
+    Ok(())
-        out,
-        "        use super::super::{{native_isa, Path, WastContext, Compiler, Features, CompilationStrategy}};"
-    )
 }
 
-fn finish_test_module(out: &mut File) -> io::Result<()> {
+fn finish_test_module(out: &mut String) -> anyhow::Result<()> {
-    writeln!(out, "    }}")
+    out.push_str("}\n");
+    Ok(())
 }
 
 fn write_testsuite_tests(
-    out: &mut File,
+    out: &mut String,
-    path: &Path,
+    path: impl AsRef<Path>,
     testsuite: &str,
     strategy: &str,
-) -> io::Result<()> {
+) -> anyhow::Result<()> {
+    let path = path.as_ref();
+    println!("cargo:rerun-if-changed={}", path.display());
     let testname = extract_name(path);
 
-    writeln!(out, "        #[test]")?;
+    writeln!(out, "#[test]")?;
     if ignore(testsuite, &testname, strategy) {
-        writeln!(out, "        #[ignore]")?;
+        writeln!(out, "#[ignore]")?;
     }
-    writeln!(out, "        fn r#{}() {{", &testname)?;
+    writeln!(out, "fn r#{}() -> anyhow::Result<()> {{", &testname)?;
-    writeln!(out, "            let isa = native_isa();")?;
     writeln!(
         out,
-        "            let compiler = Compiler::new(isa, CompilationStrategy::{});",
+        "crate::run_wast(r#\"{}\"#, crate::CompilationStrategy::{})",
+        path.display(),
         strategy
     )?;
-    writeln!(
+    writeln!(out, "}}")?;
-        out,
-        "            let features = Features {{ simd: {}, multi_value: {}, ..Default::default() }};",
-        testsuite.contains("simd"),
-        testsuite.contains("multi_value")
-    )?;
-    writeln!(
-        out,
-        "            let mut wast_context = WastContext::new(Box::new(compiler)).with_features(features);"
-    )?;
-    writeln!(out, "            wast_context")?;
-    writeln!(out, "                .register_spectest()")?;
-    writeln!(
-        out,
-        "                .expect(\"instantiating \\\"spectest\\\"\");"
-    )?;
-    writeln!(out, "            wast_context")?;
-    write!(out, "                .run_file(Path::new(\"")?;
-    // Write out the string with escape_debug to prevent special characters such
-    // as backslash from being reinterpreted.
-    for c in path.display().to_string().chars() {
-        write!(out, "{}", c.escape_debug())?;
-    }
-    writeln!(out, "\"))")?;
-    writeln!(out, "                .expect(\"error running wast file\");",)?;
-    writeln!(out, "        }}")?;
     writeln!(out)?;
     Ok(())
 }
@@ -206,66 +178,9 @@ fn ignore(testsuite: &str, testname: &str, strategy: &str) -> bool {
             // ABI only has a single return register, so we need to wait on full
             // multi-value support in Cranelift.
             (_, _) if is_multi_value => true,
-
-            // Until Windows unwind information is added we must disable SIMD spec tests that trap.
-            (_, _) if testname.starts_with("simd") => return true,
-
-            ("spec_testsuite", "address") => true,
-            ("spec_testsuite", "align") => true,
-            ("spec_testsuite", "call") => true,
-            ("spec_testsuite", "call_indirect") => true,
-            ("spec_testsuite", "conversions") => true,
-            ("spec_testsuite", "elem") => true,
-            ("spec_testsuite", "fac") => true,
-            ("spec_testsuite", "func_ptrs") => true,
-            ("spec_testsuite", "globals") => true,
-            ("spec_testsuite", "i32") => true,
-            ("spec_testsuite", "i64") => true,
-            ("spec_testsuite", "f32") => true,
-            ("spec_testsuite", "f64") => true,
-            ("spec_testsuite", "if") => true,
-            ("spec_testsuite", "imports") => true,
-            ("spec_testsuite", "int_exprs") => true,
-            ("spec_testsuite", "linking") => true,
-            ("spec_testsuite", "memory_grow") => true,
-            ("spec_testsuite", "memory_trap") => true,
-            ("spec_testsuite", "resizing") => true,
-            ("spec_testsuite", "select") => true,
-            ("spec_testsuite", "skip_stack_guard_page") => true,
-            ("spec_testsuite", "start") => true,
-            ("spec_testsuite", "traps") => true,
-            ("spec_testsuite", "unreachable") => true,
-            ("spec_testsuite", "unwind") => true,
-            ("misc_testsuite", "misc_traps") => true,
-            ("misc_testsuite", "stack_overflow") => true,
             (_, _) => false,
         };
     }
 
-    #[cfg(target_os = "linux")]
-    {
-        // Test whether the libc correctly parses the following constant; if so,
-        // we can run the "const" test. If not, the "const" test will fail, since
-        // we use wabt to parse the tests and wabt uses strtof.
-        extern "C" {
-            pub fn strtof(s: *const libc::c_char, endp: *mut *mut libc::c_char) -> libc::c_float;
-        }
-        if unsafe {
-            strtof(
-                b"8.8817847263968443574e-16" as *const u8 as *const libc::c_char,
-                core::ptr::null_mut(),
-            )
-        }
-        .to_bits()
-            != 0x26800001
-        {
-            return match (testsuite, testname) {
-                ("spec_testsuite", "const") => true,
-                ("single_file_spec_test", "simd_const") => true,
-                (_, _) => false,
-            };
-        }
-    }
-
     false
 }

docs/embed-rust.md

@@ -1,3 +1,99 @@
 # Embedding Wasmtime in Rust
 
-... more coming soon
+This document shows how to embed Wasmtime using the Rust API, and run a simple
+wasm program.
+
+# Create some wasm
+
+Let's create a simple WebAssembly file with a single exported function that returns an integer:
+
+```wat
+(;; wat2wasm hello.wat -o $WASM_FILES/hello.wasm ;;)
+(module
+  (func (export "answer") (result i32)
+     i32.const 42
+  )
+)
+```
+
+# Create rust project
+
+```
+$ cargo new --bin wasmtime_hello
+$ cd wasmtime_hello
+$ cp $WASM_FILES/hello.wasm .
+```
+
+We will be using the wasmtime engine/API to run the wasm file, so we will add the dependency to `Cargo.toml`:
+
+```
+[dependencies]
+wasmtime-api = { git = "https://github.com/CraneStation/wasmtime" }
+```
+
+It is time to add code to the `src/main.rs`. First, the engine and storage need to be activated:
+
+```rust
+use wasmtime_api::*;
+
+let engine = HostRef::new(Engine::default());
+let store = HostRef::new(Store::new(&engine));
+```
+
+The `HostRef` will be used a lot -- it is a "convenience" object to store and refer an object between the host and
+the embedded environments.
+
+The `hello.wasm` can be read from the file system and provided to the `Module` object constructor as `&[u8]`:
+
+```rust
+use std::fs::read;
+
+let hello_wasm = read("hello.wasm").expect("wasm file");
+
+let module = HostRef::new(Module::new(&store, &hello_wasm).expect("wasm module"));
+```
+
+The module instance can now be created. Normally, you would provide exports, but in this case, there is none required:
+
+```rust
+let instance = Instance::new(&store, &module, &[]).expect("wasm instance");
+```
+
+Everything is set. If a WebAssembly module has a start function -- it was run.
+The instance's exports can be used at this point. This wasm file has only one export, so we can index it directly:
+
+```rust
+let answer_fn = instance.exports()[0].func().expect("answer function");
+```
+
+The exported function can be called using the `call` method. Remember that in most of the cases, 
+a `HostRef<_>` object will be returned, so `borrow()` or `borrow_mut()` method has to be used to refer the
+specific object. The exported "answer" function accepts no parameters and returns a single `i32` value.
+
+```rust
+let result = answer_fn.borrow().call(&[]).expect("success");
+println!("Answer: {}", result[0].i32());
+```
+
+The names of the WebAssembly module's imports and exports can be discovered by means of module's corresponding methods.
+
+# src/main.rs
+
+```rust
+use std::fs::read;
+use wasmtime_api::*;
+
+fn main() {
+    let engine = HostRef::new(Engine::default());
+    let store = HostRef::new(Store::new(&engine));
+
+    let wasm = read("hello.wasm").expect("wasm file");
+
+    let module = HostRef::new(Module::new(&store, &wasm).expect("wasm module"));
+    let instance = Instance::new(&store, &module, &[]).expect("wasm instance");
+
+    let answer_fn = instance.exports()[0].func().expect("answer function");
+    let result = answer_fn.borrow().call(&[]).expect("success");
+    println!("Answer: {}", result[0].i32());
+}
+```

lightbeam/src/microwasm.rs

@@ -1179,8 +1179,12 @@ where
                 sig!((ty) -> (ty))
             }
 
-            WasmOperator::GetGlobal { global_index } => sig!(() -> (self.module.global_type(*global_index).to_microwasm_type())),
+            WasmOperator::GetGlobal { global_index } => {
-            WasmOperator::SetGlobal { global_index } => sig!((self.module.global_type(*global_index).to_microwasm_type()) -> ()),
+                sig!(() -> (self.module.global_type(*global_index).to_microwasm_type()))
+            }
+            WasmOperator::SetGlobal { global_index } => {
+                sig!((self.module.global_type(*global_index).to_microwasm_type()) -> ())
+            }
 
             WasmOperator::F32Load { .. } => sig!((I32) -> (F32)),
             WasmOperator::F64Load { .. } => sig!((I32) -> (F64)),
@@ -1259,8 +1263,12 @@ where
             | WasmOperator::F64Le
             | WasmOperator::F64Ge => sig!((F64, F64) -> (I32)),
 
-            WasmOperator::I32Clz | WasmOperator::I32Ctz | WasmOperator::I32Popcnt => sig!((I32) -> (I32)),
+            WasmOperator::I32Clz | WasmOperator::I32Ctz | WasmOperator::I32Popcnt => {
-            WasmOperator::I64Clz | WasmOperator::I64Ctz | WasmOperator::I64Popcnt => sig!((I64) -> (I64)),
+                sig!((I32) -> (I32))
+            }
+            WasmOperator::I64Clz | WasmOperator::I64Ctz | WasmOperator::I64Popcnt => {
+                sig!((I64) -> (I64))
+            }
 
             WasmOperator::I32Add
             | WasmOperator::I32Sub

lightbeam/src/tests.rs

@@ -1027,18 +1027,18 @@ test_select!(select64, i64);
 mod benches {
     extern crate test;
 
-    use super::{translate, wabt, FIBONACCI, FIBONACCI_OPT};
+    use super::{translate, FIBONACCI, FIBONACCI_OPT};
 
     #[bench]
     fn bench_fibonacci_compile(b: &mut test::Bencher) {
-        let wasm = wabt::wat2wasm(FIBONACCI).unwrap();
+        let wasm = wat::parse_str(FIBONACCI).unwrap();
 
         b.iter(|| test::black_box(translate(&wasm).unwrap()));
     }
 
     #[bench]
     fn bench_fibonacci_run(b: &mut test::Bencher) {
-        let wasm = wabt::wat2wasm(FIBONACCI_OPT).unwrap();
+        let wasm = wat::parse_str(FIBONACCI_OPT).unwrap();
         let module = translate(&wasm).unwrap();
 
         b.iter(|| module.execute_func::<_, u32>(0, (20,)));
@@ -1046,7 +1046,7 @@ mod benches {
 
     #[bench]
     fn bench_fibonacci_compile_run(b: &mut test::Bencher) {
-        let wasm = wabt::wat2wasm(FIBONACCI).unwrap();
+        let wasm = wat::parse_str(FIBONACCI).unwrap();
 
         b.iter(|| translate(&wasm).unwrap().execute_func::<_, u32>(0, (20,)));
     }

misc/wasmtime-py/src/import.rs

@@ -16,7 +16,7 @@ use cranelift_entity::{EntityRef, PrimaryMap};
 use cranelift_frontend::{FunctionBuilder, FunctionBuilderContext};
 use cranelift_wasm::{DefinedFuncIndex, FuncIndex};
 use target_lexicon::HOST;
-use wasmtime_environ::{Export, Module};
+use wasmtime_environ::{CompiledFunction, Export, Module};
 use wasmtime_jit::CodeMemory;
 use wasmtime_runtime::{Imports, InstanceHandle, VMContext, VMFunctionBody};
 
@@ -184,9 +184,16 @@ fn make_trampoline(
         )
         .expect("compile_and_emit");
 
+    let mut unwind_info = Vec::new();
+    context.emit_unwind_info(isa, &mut unwind_info);
+
     code_memory
-        .allocate_copy_of_byte_slice(&code_buf)
+        .allocate_for_function(&CompiledFunction {
-        .expect("allocate_copy_of_byte_slice")
+            body: code_buf,
+            jt_offsets: context.func.jt_offsets,
+            unwind_info,
+        })
+        .expect("allocate_for_function")
         .as_ptr()
 }
 

src/bin/wasmtime.rs

@@ -270,14 +270,14 @@ fn main() -> Result<()> {
         strategy,
     );
     let engine = HostRef::new(Engine::new(config));
-    let store = HostRef::new(Store::new(engine));
+    let store = HostRef::new(Store::new(&engine));
 
     let mut module_registry = HashMap::new();
 
     // Make spectest available by default.
     module_registry.insert(
         "spectest".to_owned(),
-        Instance::from_handle(store.clone(), instantiate_spectest()?)?,
+        Instance::from_handle(&store, instantiate_spectest()?)?,
     );
 
     // Make wasi available by default.
@@ -301,36 +301,36 @@ fn main() -> Result<()> {
 
     module_registry.insert(
         "wasi_unstable".to_owned(),
-        Instance::from_handle(store.clone(), wasi.clone())?,
+        Instance::from_handle(&store, wasi.clone())?,
     );
     module_registry.insert(
         "wasi_unstable_preview0".to_owned(),
-        Instance::from_handle(store.clone(), wasi)?,
+        Instance::from_handle(&store, wasi)?,
     );
 
     // Load the preload wasm modules.
     for filename in &args.flag_preload {
         let path = Path::new(&filename);
-        instantiate_module(store.clone(), &module_registry, path)
+        instantiate_module(&store, &module_registry, path)
             .with_context(|| format!("failed to process preload at `{}`", path.display()))?;
     }
 
     // Load the main wasm module.
     let path = Path::new(&args.arg_file);
-    handle_module(store, &module_registry, &args, path)
+    handle_module(&store, &module_registry, &args, path)
         .with_context(|| format!("failed to process main module `{}`", path.display()))?;
     Ok(())
 }
 
 fn instantiate_module(
-    store: HostRef<Store>,
+    store: &HostRef<Store>,
     module_registry: &HashMap<String, (Instance, HashMap<String, usize>)>,
     path: &Path,
 ) -> Result<(HostRef<Instance>, HostRef<Module>, Vec<u8>)> {
     // Read the wasm module binary either as `*.wat` or a raw binary
     let data = wat::parse_file(path.to_path_buf())?;
 
-    let module = HostRef::new(Module::new(store.clone(), &data)?);
+    let module = HostRef::new(Module::new(store, &data)?);
 
     // Resolve import using module_registry.
     let imports = module
@@ -356,18 +356,18 @@ fn instantiate_module(
         })
         .collect::<Result<Vec<_>, _>>()?;
 
-    let instance = HostRef::new(Instance::new(store.clone(), module.clone(), &imports)?);
+    let instance = HostRef::new(Instance::new(store, &module, &imports)?);
 
     Ok((instance, module, data))
 }
 
 fn handle_module(
-    store: HostRef<Store>,
+    store: &HostRef<Store>,
     module_registry: &HashMap<String, (Instance, HashMap<String, usize>)>,
     args: &Args,
     path: &Path,
 ) -> Result<()> {
-    let (instance, _module, data) = instantiate_module(store.clone(), module_registry, path)?;
+    let (instance, _module, data) = instantiate_module(store, module_registry, path)?;
 
     // If a function to invoke was given, invoke it.
     if let Some(f) = &args.flag_invoke {
@@ -379,7 +379,7 @@ fn handle_module(
 }
 
 fn invoke_export(
-    store: HostRef<Store>,
+    store: &HostRef<Store>,
     instance: HostRef<Instance>,
     data: &ModuleData,
     name: &str,

tests/wast_testsuites.rs

@@ -9,7 +9,24 @@ use wasmtime_wast::WastContext;
 
 include!(concat!(env!("OUT_DIR"), "/wast_testsuite_tests.rs"));
 
-#[cfg(test)]
+// Each of the tests included from `wast_testsuite_tests` will call this
+// function which actually executes the `wast` test suite given the `strategy`
+// to compile it.
+fn run_wast(wast: &str, strategy: CompilationStrategy) -> anyhow::Result<()> {
+    let wast = Path::new(wast);
+    let isa = native_isa();
+    let compiler = Compiler::new(isa, strategy);
+    let features = Features {
+        simd: wast.iter().any(|s| s == "simd"),
+        multi_value: wast.iter().any(|s| s == "multi-value"),
+        ..Default::default()
+    };
+    let mut wast_context = WastContext::new(Box::new(compiler)).with_features(features);
+    wast_context.register_spectest()?;
+    wast_context.run_file(wast)?;
+    Ok(())
+}
+
 fn native_isa() -> Box<dyn isa::TargetIsa> {
     let mut flag_builder = settings::builder();
     flag_builder.enable("enable_verifier").unwrap();

wasmtime-api/Cargo.toml

@@ -30,7 +30,6 @@ hashbrown = { version = "0.6.0", optional = true }
 [features]
 default = ["std"]
 std = ["cranelift-codegen/std", "cranelift-wasm/std", "wasmtime-environ/std", "wasmparser/std"]
-wasm-c-api = []
 core = ["hashbrown/nightly", "cranelift-codegen/core", "cranelift-wasm/core", "wasmtime-environ/core", "wasmparser/core"]
 
 [dev-dependencies]

wasmtime-api/c-examples/Makefile

@@ -46,9 +46,9 @@ WASM_CC_LIBS = $(error unsupported C++)
 
 # Compiler config
 ifeq (${WASMTIME_API_MODE},release)
-  CARGO_BUILD_FLAGS = --features "wasm-c-api" --release
+  CARGO_BUILD_FLAGS = --release
 else
-  CARGO_BUILD_FLAGS = --features "wasm-c-api"
+  CARGO_BUILD_FLAGS =
 endif
 
 ifeq (${C_COMP},clang)

wasmtime-api/examples/gcd.rs

@@ -10,10 +10,10 @@ fn main() -> Result<()> {
 
     // Instantiate engine and store.
     let engine = HostRef::new(Engine::default());
-    let store = HostRef::new(Store::new(engine));
+    let store = HostRef::new(Store::new(&engine));
 
     // Load a module.
-    let module = HostRef::new(Module::new(store.clone(), &wasm)?);
+    let module = HostRef::new(Module::new(&store, &wasm)?);
 
     // Find index of the `gcd` export.
     let gcd_index = module
@@ -26,7 +26,7 @@ fn main() -> Result<()> {
         .0;
 
     // Instantiate the module.
-    let instance = HostRef::new(Instance::new(store.clone(), module, &[])?);
+    let instance = HostRef::new(Instance::new(&store, &module, &[])?);
 
     // Invoke `gcd` export
     let gcd = instance.borrow().exports()[gcd_index]

wasmtime-api/examples/hello.rs

@@ -21,8 +21,8 @@ impl Callable for HelloCallback {
 fn main() -> Result<()> {
     // Initialize.
     println!("Initializing...");
-    let engine = HostRef::new(Engine::new(Config::default()));
+    let engine = HostRef::new(Engine::default());
-    let store = HostRef::new(Store::new(engine));
+    let store = HostRef::new(Store::new(&engine));
 
     // Load binary.
     println!("Loading binary...");
@@ -30,19 +30,18 @@ fn main() -> Result<()> {
 
     // Compile.
     println!("Compiling module...");
-    let module =
+    let module = HostRef::new(Module::new(&store, &binary).context("> Error compiling module!")?);
-        HostRef::new(Module::new(store.clone(), &binary).context("> Error compiling module!")?);
 
     // Create external print functions.
     println!("Creating callback...");
     let hello_type = FuncType::new(Box::new([]), Box::new([]));
-    let hello_func = HostRef::new(Func::new(store.clone(), hello_type, Rc::new(HelloCallback)));
+    let hello_func = HostRef::new(Func::new(&store, hello_type, Rc::new(HelloCallback)));
 
     // Instantiate.
     println!("Instantiating module...");
     let imports = vec![hello_func.into()];
     let instance = HostRef::new(
-        Instance::new(store.clone(), module, imports.as_slice())
+        Instance::new(&store, &module, imports.as_slice())
             .context("> Error instantiating module!")?,
     );
 

wasmtime-api/examples/memory.rs

@@ -64,8 +64,8 @@ macro_rules! call {
 fn main() -> Result<(), Error> {
     // Initialize.
     println!("Initializing...");
-    let engine = HostRef::new(Engine::new(Config::default()));
+    let engine = HostRef::new(Engine::default());
-    let store = HostRef::new(Store::new(engine));
+    let store = HostRef::new(Store::new(&engine));
 
     // Load binary.
     println!("Loading binary...");
@@ -73,14 +73,12 @@ fn main() -> Result<(), Error> {
 
     // Compile.
     println!("Compiling module...");
-    let module =
+    let module = HostRef::new(Module::new(&store, &binary).context("> Error compiling module!")?);
-        HostRef::new(Module::new(store.clone(), &binary).context("> Error compiling module!")?);
 
     // Instantiate.
     println!("Instantiating module...");
-    let instance = HostRef::new(
+    let instance =
-        Instance::new(store.clone(), module, &[]).context("> Error instantiating module!")?,
+        HostRef::new(Instance::new(&store, &module, &[]).context("> Error instantiating module!")?);
-    );
 
     // Extract export.
     println!("Extracting export...");
@@ -141,7 +139,7 @@ fn main() -> Result<(), Error> {
     // TODO(wasm+): Once Wasm allows multiple memories, turn this into import.
     println!("Creating stand-alone memory...");
     let memorytype = MemoryType::new(Limits::new(5, 5));
-    let mut memory2 = Memory::new(store.clone(), memorytype);
+    let mut memory2 = Memory::new(&store, memorytype);
     check!(memory2.size(), 5u32);
     check!(memory2.grow(1), false);
     check!(memory2.grow(0), true);

wasmtime-api/examples/multi.rs

@@ -24,8 +24,8 @@ impl Callable for Callback {
 fn main() -> Result<()> {
     // Initialize.
     println!("Initializing...");
-    let engine = HostRef::new(Engine::new(Config::default()));
+    let engine = HostRef::new(Engine::default());
-    let store = HostRef::new(Store::new(engine));
+    let store = HostRef::new(Store::new(&engine));
 
     // Load binary.
     println!("Loading binary...");
@@ -33,8 +33,7 @@ fn main() -> Result<()> {
 
     // Compile.
     println!("Compiling module...");
-    let module =
+    let module = HostRef::new(Module::new(&store, &binary).context("Error compiling module!")?);
-        HostRef::new(Module::new(store.clone(), &binary).context("Error compiling module!")?);
 
     // Create external print functions.
     println!("Creating callback...");
@@ -42,13 +41,13 @@ fn main() -> Result<()> {
         Box::new([ValType::I32, ValType::I64]),
         Box::new([ValType::I64, ValType::I32]),
     );
-    let callback_func = HostRef::new(Func::new(store.clone(), callback_type, Rc::new(Callback)));
+    let callback_func = HostRef::new(Func::new(&store, callback_type, Rc::new(Callback)));
 
     // Instantiate.
     println!("Instantiating module...");
     let imports = vec![callback_func.into()];
     let instance = HostRef::new(
-        Instance::new(store.clone(), module, imports.as_slice())
+        Instance::new(&store, &module, imports.as_slice())
             .context("Error instantiating module!")?,
     );
 

wasmtime-api/src/callable.rs

@@ -34,9 +34,9 @@ pub(crate) struct WasmtimeFn {
 }
 
 impl WasmtimeFn {
-    pub fn new(store: HostRef<Store>, instance: InstanceHandle, export: Export) -> WasmtimeFn {
+    pub fn new(store: &HostRef<Store>, instance: InstanceHandle, export: Export) -> WasmtimeFn {
         WasmtimeFn {
-            store,
+            store: store.clone(),
             instance,
             export,
         }

wasmtime-api/src/externals.rs

@@ -66,7 +66,7 @@ impl Extern {
     }
 
     pub(crate) fn from_wasmtime_export(
-        store: HostRef<Store>,
+        store: &HostRef<Store>,
         instance_handle: InstanceHandle,
         export: wasmtime_runtime::Export,
     ) -> Extern {
@@ -118,18 +118,18 @@ pub struct Func {
 }
 
 impl Func {
-    pub fn new(store: HostRef<Store>, ty: FuncType, callable: Rc<dyn Callable + 'static>) -> Self {
+    pub fn new(store: &HostRef<Store>, ty: FuncType, callable: Rc<dyn Callable + 'static>) -> Self {
         let callable = Rc::new(NativeCallable::new(callable, &ty, &store));
         Func::from_wrapped(store, ty, callable)
     }
 
     fn from_wrapped(
-        store: HostRef<Store>,
+        store: &HostRef<Store>,
         r#type: FuncType,
         callable: Rc<dyn WrappedCallable + 'static>,
     ) -> Func {
         Func {
-            _store: store,
+            _store: store.clone(),
             callable,
             r#type,
         }
@@ -159,7 +159,7 @@ impl Func {
 
     pub(crate) fn from_wasmtime_function(
         export: wasmtime_runtime::Export,
-        store: HostRef<Store>,
+        store: &HostRef<Store>,
         instance_handle: InstanceHandle,
     ) -> Self {
         let ty = if let wasmtime_runtime::Export::Function { signature, .. } = &export {
@@ -167,7 +167,7 @@ impl Func {
         } else {
             panic!("expected function export")
         };
-        let callable = WasmtimeFn::new(store.clone(), instance_handle, export.clone());
+        let callable = WasmtimeFn::new(store, instance_handle, export.clone());
         Func::from_wrapped(store, ty, Rc::new(callable))
     }
 }
@@ -187,11 +187,11 @@ pub struct Global {
 }
 
 impl Global {
-    pub fn new(store: HostRef<Store>, r#type: GlobalType, val: Val) -> Global {
+    pub fn new(store: &HostRef<Store>, r#type: GlobalType, val: Val) -> Global {
         let (wasmtime_export, wasmtime_state) =
             generate_global_export(&r#type, val).expect("generated global");
         Global {
-            _store: store,
+            _store: store.clone(),
             r#type,
             wasmtime_export,
             wasmtime_state: Some(wasmtime_state),
@@ -248,7 +248,7 @@ impl Global {
 
     pub(crate) fn from_wasmtime_global(
         export: wasmtime_runtime::Export,
-        store: HostRef<Store>,
+        store: &HostRef<Store>,
     ) -> Global {
         let global = if let wasmtime_runtime::Export::Global { ref global, .. } = export {
             global
@@ -257,7 +257,7 @@ impl Global {
         };
         let ty = GlobalType::from_cranelift_global(global.clone());
         Global {
-            _store: store,
+            _store: store.clone(),
             r#type: ty,
             wasmtime_export: export,
             wasmtime_state: None,
@@ -302,7 +302,7 @@ fn set_table_item(
 }
 
 impl Table {
-    pub fn new(store: HostRef<Store>, r#type: TableType, init: Val) -> Table {
+    pub fn new(store: &HostRef<Store>, r#type: TableType, init: Val) -> Table {
         match r#type.element() {
             ValType::FuncRef => (),
             _ => panic!("table is not for funcref"),
@@ -317,7 +317,7 @@ impl Table {
                 let len = unsafe { (*definition).current_elements };
                 for i in 0..len {
                     let _success =
-                        set_table_item(&mut wasmtime_handle, &store, index, i, init.clone());
+                        set_table_item(&mut wasmtime_handle, store, index, i, init.clone());
                     assert!(_success);
                 }
             }
@@ -325,7 +325,7 @@ impl Table {
         }
 
         Table {
-            store,
+            store: store.clone(),
             r#type,
             wasmtime_handle,
             wasmtime_export,
@@ -387,7 +387,7 @@ impl Table {
 
     pub(crate) fn from_wasmtime_table(
         export: wasmtime_runtime::Export,
-        store: HostRef<Store>,
+        store: &HostRef<Store>,
         instance_handle: wasmtime_runtime::InstanceHandle,
     ) -> Table {
         let table = if let wasmtime_runtime::Export::Table { ref table, .. } = export {
@@ -397,7 +397,7 @@ impl Table {
         };
         let ty = TableType::from_cranelift_table(table.table.clone());
         Table {
-            store,
+            store: store.clone(),
             r#type: ty,
             wasmtime_handle: instance_handle,
             wasmtime_export: export,
@@ -413,11 +413,11 @@ pub struct Memory {
 }
 
 impl Memory {
-    pub fn new(store: HostRef<Store>, r#type: MemoryType) -> Memory {
+    pub fn new(store: &HostRef<Store>, r#type: MemoryType) -> Memory {
         let (wasmtime_handle, wasmtime_export) =
             generate_memory_export(&r#type).expect("generated memory");
         Memory {
-            _store: store,
+            _store: store.clone(),
             r#type,
             wasmtime_handle,
             wasmtime_export,
@@ -471,7 +471,7 @@ impl Memory {
 
     pub(crate) fn from_wasmtime_memory(
         export: wasmtime_runtime::Export,
-        store: HostRef<Store>,
+        store: &HostRef<Store>,
         instance_handle: wasmtime_runtime::InstanceHandle,
     ) -> Memory {
         let memory = if let wasmtime_runtime::Export::Memory { ref memory, .. } = export {
@@ -481,7 +481,7 @@ impl Memory {
         };
         let ty = MemoryType::from_cranelift_memory(memory.memory.clone());
         Memory {
-            _store: store,
+            _store: store.clone(),
             r#type: ty,
             wasmtime_handle: instance_handle,
             wasmtime_export: export,

wasmtime-api/src/instance.rs

@@ -61,8 +61,8 @@ pub struct Instance {
 
 impl Instance {
     pub fn new(
-        store: HostRef<Store>,
+        store: &HostRef<Store>,
-        module: HostRef<Module>,
+        module: &HostRef<Module>,
         externs: &[Extern],
     ) -> Result<Instance> {
         let context = store.borrow_mut().context().clone();
@@ -84,7 +84,7 @@ impl Instance {
                 let name = export.name().to_string();
                 let export = instance_handle.lookup(&name).expect("export");
                 exports.push(Extern::from_wasmtime_export(
-                    store.clone(),
+                    store,
                     instance_handle.clone(),
                     export,
                 ));
@@ -103,7 +103,7 @@ impl Instance {
     }
 
     pub fn from_handle(
-        store: HostRef<Store>,
+        store: &HostRef<Store>,
         instance_handle: InstanceHandle,
     ) -> Result<(Instance, HashMap<String, usize>)> {
         let contexts = HashSet::new();
@@ -121,7 +121,7 @@ impl Instance {
             }
             export_names_map.insert(name.to_owned(), exports.len());
             exports.push(Extern::from_wasmtime_export(
-                store.clone(),
+                store,
                 instance_handle.clone(),
                 export.clone(),
             ));

wasmtime-api/src/lib.rs

@@ -14,7 +14,6 @@ mod trap;
 mod types;
 mod values;
 
-#[cfg(feature = "wasm-c-api")]
 pub mod wasm;
 
 #[macro_use]

wasmtime-api/src/module.rs

@@ -182,10 +182,10 @@ pub struct Module {
 }
 
 impl Module {
-    pub fn new(store: HostRef<Store>, binary: &[u8]) -> Result<Module> {
+    pub fn new(store: &HostRef<Store>, binary: &[u8]) -> Result<Module> {
         let (imports, exports) = read_imports_and_exports(binary)?;
         Ok(Module {
-            store,
+            store: store.clone(),
             binary: binary.into(),
             imports,
             exports,

wasmtime-api/src/runtime.rs

@@ -102,13 +102,13 @@ pub struct Store {
 }
 
 impl Store {
-    pub fn new(engine: HostRef<Engine>) -> Store {
+    pub fn new(engine: &HostRef<Engine>) -> Store {
         let flags = engine.borrow().config().flags().clone();
         let features = engine.borrow().config().features().clone();
         let debug_info = engine.borrow().config().debug_info();
         let strategy = engine.borrow().config().strategy();
         Store {
-            engine,
+            engine: engine.clone(),
             context: Context::create(flags, features, debug_info, strategy),
             global_exports: Rc::new(RefCell::new(HashMap::new())),
             signature_cache: HashMap::new(),

wasmtime-api/src/trampoline/func.rs

@@ -9,8 +9,7 @@ use cranelift_codegen::{binemit, ir, isa};
 use cranelift_entity::{EntityRef, PrimaryMap};
 use cranelift_frontend::{FunctionBuilder, FunctionBuilderContext};
 use cranelift_wasm::{DefinedFuncIndex, FuncIndex};
-//use target_lexicon::HOST;
+use wasmtime_environ::{CompiledFunction, Export, Module};
-use wasmtime_environ::{Export, Module};
 use wasmtime_jit::CodeMemory;
 use wasmtime_runtime::{InstanceHandle, VMContext, VMFunctionBody};
 
@@ -185,9 +184,16 @@ fn make_trampoline(
         )
         .expect("compile_and_emit");
 
+    let mut unwind_info = Vec::new();
+    context.emit_unwind_info(isa, &mut unwind_info);
+
     code_memory
-        .allocate_copy_of_byte_slice(&code_buf)
+        .allocate_for_function(&CompiledFunction {
-        .expect("allocate_copy_of_byte_slice")
+            body: code_buf,
+            jt_offsets: context.func.jt_offsets,
+            unwind_info,
+        })
+        .expect("allocate_for_function")
         .as_ptr()
 }
 

wasmtime-api/src/values.rs

@@ -230,6 +230,6 @@ pub(crate) fn from_checked_anyfunc(
         signature,
         vmctx: item.vmctx,
     };
-    let f = Func::from_wasmtime_function(export, store.clone(), instance_handle);
+    let f = Func::from_wasmtime_function(export, store, instance_handle);
     Val::FuncRef(HostRef::new(f))
 }

wasmtime-api/src/wasm.rs

@@ -609,7 +609,7 @@ pub unsafe extern "C" fn wasm_func_new(
     ty: *const wasm_functype_t,
     callback: wasm_func_callback_t,
 ) -> *mut wasm_func_t {
-    let store = (*store).store.clone();
+    let store = &(*store).store;
     let ty = (*ty).functype.clone();
     let callback = Rc::new(callback);
     let func = Box::new(wasm_func_t {
@@ -663,13 +663,13 @@ pub unsafe extern "C" fn wasm_instance_new(
     imports: *const *const wasm_extern_t,
     result: *mut *mut wasm_trap_t,
 ) -> *mut wasm_instance_t {
-    let store = (*store).store.clone();
+    let store = &(*store).store;
     let mut externs: Vec<Extern> = Vec::with_capacity((*module).imports.len());
     for i in 0..(*module).imports.len() {
         let import = *imports.offset(i as isize);
         externs.push((*import).ext.clone());
     }
-    let module = (*module).module.clone();
+    let module = &(*module).module;
     match Instance::new(store, module, &externs) {
         Ok(instance) => {
             let instance = Box::new(wasm_instance_t {
@@ -731,7 +731,7 @@ pub unsafe extern "C" fn wasm_module_new(
     binary: *const wasm_byte_vec_t,
 ) -> *mut wasm_module_t {
     let binary = (*binary).as_slice();
-    let store = (*store).store.clone();
+    let store = &(*store).store;
     let module = Module::new(store, binary).expect("module");
     let imports = module
         .imports()
@@ -766,9 +766,9 @@ pub unsafe extern "C" fn wasm_store_delete(store: *mut wasm_store_t) {
 
 #[no_mangle]
 pub unsafe extern "C" fn wasm_store_new(engine: *mut wasm_engine_t) -> *mut wasm_store_t {
-    let engine = (*engine).engine.clone();
+    let engine = &(*engine).engine;
     let store = Box::new(wasm_store_t {
-        store: HostRef::new(Store::new(engine)),
+        store: HostRef::new(Store::new(&engine)),
     });
     Box::into_raw(store)
 }
@@ -804,7 +804,7 @@ pub unsafe extern "C" fn wasm_func_new_with_env(
     env: *mut ::core::ffi::c_void,
     finalizer: ::core::option::Option<unsafe extern "C" fn(arg1: *mut ::core::ffi::c_void)>,
 ) -> *mut wasm_func_t {
-    let store = (*store).store.clone();
+    let store = &(*store).store;
     let ty = (*ty).functype.clone();
     let callback = Rc::new(CallbackWithEnv {
         callback,
@@ -1327,7 +1327,7 @@ pub unsafe extern "C" fn wasm_global_new(
     val: *const wasm_val_t,
 ) -> *mut wasm_global_t {
     let global = HostRef::new(Global::new(
-        (*store).store.clone(),
+        &(*store).store,
         (*gt).globaltype.clone(),
         (*val).val(),
     ));
@@ -1446,10 +1446,7 @@ pub unsafe extern "C" fn wasm_memory_new(
     store: *mut wasm_store_t,
     mt: *const wasm_memorytype_t,
 ) -> *mut wasm_memory_t {
-    let memory = HostRef::new(Memory::new(
+    let memory = HostRef::new(Memory::new(&(*store).store, (*mt).memorytype.clone()));
-        (*store).store.clone(),
-        (*mt).memorytype.clone(),
-    ));
     let m = Box::new(wasm_memory_t { memory, ext: None });
     Box::into_raw(m)
 }
@@ -1537,11 +1534,7 @@ pub unsafe extern "C" fn wasm_table_new(
         Val::AnyRef(AnyRef::Null)
     };
     let t = Box::new(wasm_table_t {
-        table: HostRef::new(Table::new(
+        table: HostRef::new(Table::new(&(*store).store, (*tt).tabletype.clone(), init)),
-            (*store).store.clone(),
-            (*tt).tabletype.clone(),
-            init,
-        )),
         ext: None,
     });
     Box::into_raw(t)

wasmtime-api/tests/import_calling_export.rs

@@ -25,10 +25,10 @@ fn test_import_calling_export() {
     }
 
     let engine = HostRef::new(Engine::new(Config::default()));
-    let store = HostRef::new(Store::new(engine));
+    let store = HostRef::new(Store::new(&engine));
     let module = HostRef::new(
         Module::new(
-            store.clone(),
+            &store,
             &read("tests/import_calling_export.wasm").expect("failed to read wasm file"),
         )
         .expect("failed to create module"),
@@ -39,15 +39,14 @@ fn test_import_calling_export() {
     });
 
     let callback_func = HostRef::new(Func::new(
-        store.clone(),
+        &store,
         FuncType::new(Box::new([]), Box::new([])),
         callback.clone(),
     ));
 
     let imports = vec![callback_func.into()];
     let instance = HostRef::new(
-        Instance::new(store.clone(), module, imports.as_slice())
+        Instance::new(&store, &module, imports.as_slice()).expect("failed to instantiate module"),
-            .expect("failed to instantiate module"),
     );
 
     let exports = Ref::map(instance.borrow(), |instance| instance.exports());

wasmtime-environ/src/cache/tests.rs

@@ -1,7 +1,7 @@
 use super::config::tests::test_prolog;
 use super::*;
 use crate::address_map::{FunctionAddressMap, InstructionAddressMap};
-use crate::compilation::{CodeAndJTOffsets, Relocation, RelocationTarget, TrapInformation};
+use crate::compilation::{CompiledFunction, Relocation, RelocationTarget, TrapInformation};
 use crate::module::{MemoryPlan, MemoryStyle, Module};
 use alloc::boxed::Box;
 use alloc::vec::Vec;
@@ -258,9 +258,10 @@ fn new_module_cache_data(rng: &mut impl Rng) -> ModuleCacheData {
                     *v = (j as u32) * 3 / 4
                 }
             });
-            CodeAndJTOffsets {
+            CompiledFunction {
                 body: (0..(i * 3 / 2)).collect(),
                 jt_offsets: sm,
+                unwind_info: (0..(i * 3 / 2)).collect(),
             }
         })
         .collect();

wasmtime-environ/src/compilation.rs

@@ -12,17 +12,20 @@ use serde::{Deserialize, Serialize};
 use std::ops::Range;
 use thiserror::Error;
 
-/// Compiled machine code: body and jump table offsets.
+/// Compiled function: machine code body, jump table offsets, and unwind information.
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq)]
-pub struct CodeAndJTOffsets {
+pub struct CompiledFunction {
     /// The function body.
     pub body: Vec<u8>,
 
     /// The jump tables offsets (in the body).
     pub jt_offsets: ir::JumpTableOffsets,
+
+    /// The unwind information.
+    pub unwind_info: Vec<u8>,
 }
 
-type Functions = PrimaryMap<DefinedFuncIndex, CodeAndJTOffsets>;
+type Functions = PrimaryMap<DefinedFuncIndex, CompiledFunction>;
 
 /// The result of compiling a WebAssembly module's functions.
 #[derive(Deserialize, Serialize, Debug, PartialEq, Eq)]
@@ -40,21 +43,22 @@ impl Compilation {
     /// Allocates the compilation result with the given function bodies.
     pub fn from_buffer(
         buffer: Vec<u8>,
-        functions: impl IntoIterator<Item = (Range<usize>, ir::JumpTableOffsets)>,
+        functions: impl IntoIterator<Item = (Range<usize>, ir::JumpTableOffsets, Range<usize>)>,
     ) -> Self {
         Self::new(
             functions
                 .into_iter()
-                .map(|(range, jt_offsets)| CodeAndJTOffsets {
+                .map(|(body_range, jt_offsets, unwind_range)| CompiledFunction {
-                    body: buffer[range].to_vec(),
+                    body: buffer[body_range].to_vec(),
                     jt_offsets,
+                    unwind_info: buffer[unwind_range].to_vec(),
                 })
                 .collect(),
         )
     }
 
     /// Gets the bytes of a single function
-    pub fn get(&self, func: DefinedFuncIndex) -> &CodeAndJTOffsets {
+    pub fn get(&self, func: DefinedFuncIndex) -> &CompiledFunction {
         &self.functions[func]
     }
 
@@ -67,7 +71,7 @@ impl Compilation {
     pub fn get_jt_offsets(&self) -> PrimaryMap<DefinedFuncIndex, ir::JumpTableOffsets> {
         self.functions
             .iter()
-            .map(|(_, code_and_jt)| code_and_jt.jt_offsets.clone())
+            .map(|(_, func)| func.jt_offsets.clone())
             .collect::<PrimaryMap<DefinedFuncIndex, _>>()
     }
 }
@@ -88,7 +92,7 @@ pub struct Iter<'a> {
 }
 
 impl<'a> Iterator for Iter<'a> {
-    type Item = &'a CodeAndJTOffsets;
+    type Item = &'a CompiledFunction;
 
     fn next(&mut self) -> Option<Self::Item> {
         self.iterator.next().map(|(_, b)| b)

wasmtime-environ/src/cranelift.rs

@@ -5,7 +5,7 @@ use crate::address_map::{
 };
 use crate::cache::{ModuleCacheData, ModuleCacheEntry};
 use crate::compilation::{
-    CodeAndJTOffsets, Compilation, CompileError, Relocation, RelocationTarget, Relocations,
+    Compilation, CompileError, CompiledFunction, Relocation, RelocationTarget, Relocations,
     TrapInformation, Traps,
 };
 use crate::func_environ::{
@@ -235,6 +235,7 @@ impl crate::compilation::Compiler for Cranelift {
                             )?;
 
                             let mut code_buf: Vec<u8> = Vec::new();
+                            let mut unwind_info = Vec::new();
                             let mut reloc_sink = RelocSink::new(func_index);
                             let mut trap_sink = TrapSink::new();
                             let mut stackmap_sink = binemit::NullStackmapSink {};
@@ -246,7 +247,7 @@ impl crate::compilation::Compiler for Cranelift {
                                 &mut stackmap_sink,
                             )?;
 
-                            let jt_offsets = context.func.jt_offsets.clone();
+                            context.emit_unwind_info(isa, &mut unwind_info);
 
                             let address_transform = if generate_debug_info {
                                 let body_len = code_buf.len();
@@ -261,16 +262,15 @@ impl crate::compilation::Compiler for Cranelift {
                                 None
                             };
 
-                            let stack_slots = context.func.stack_slots.clone();
-
                             Ok((
                                 code_buf,
-                                jt_offsets,
+                                context.func.jt_offsets,
                                 reloc_sink.func_relocs,
                                 address_transform,
                                 ranges,
-                                stack_slots,
+                                context.func.stack_slots,
                                 trap_sink.traps,
+                                unwind_info,
                             ))
                         },
                     )
@@ -285,10 +285,12 @@ impl crate::compilation::Compiler for Cranelift {
                             ranges,
                             sss,
                             function_traps,
+                            unwind_info,
                         )| {
-                            functions.push(CodeAndJTOffsets {
+                            functions.push(CompiledFunction {
                                 body: function,
                                 jt_offsets: func_jt_offsets,
+                                unwind_info,
                             });
                             relocations.push(relocs);
                             if let Some(address_transform) = address_transform {

wasmtime-environ/src/lib.rs

@@ -46,8 +46,8 @@ pub use crate::address_map::{
 };
 pub use crate::cache::{create_new_config as cache_create_new_config, init as cache_init};
 pub use crate::compilation::{
-    Compilation, CompileError, Compiler, Relocation, RelocationTarget, Relocations,
+    Compilation, CompileError, CompiledFunction, Compiler, Relocation, RelocationTarget,
-    TrapInformation, Traps,
+    Relocations, TrapInformation, Traps,
 };
 pub use crate::cranelift::Cranelift;
 pub use crate::func_environ::BuiltinFunctionIndex;

wasmtime-environ/src/lightbeam.rs

@@ -65,10 +65,11 @@ impl crate::compilation::Compiler for Lightbeam {
 
         // TODO pass jump table offsets to Compilation::from_buffer() when they
         // are implemented in lightbeam -- using empty set of offsets for now.
+        // TODO: pass an empty range for the unwind information until lightbeam emits it
         let code_section_ranges_and_jt = code_section
             .funcs()
             .into_iter()
-            .map(|r| (r, SecondaryMap::new()));
+            .map(|r| (r, SecondaryMap::new(), 0..0));
 
         Ok((
             Compilation::from_buffer(code_section.buffer().to_vec(), code_section_ranges_and_jt),

wasmtime-jit/Cargo.toml

@@ -25,6 +25,9 @@ target-lexicon = { version = "0.9.0", default-features = false }
 hashbrown = { version = "0.6.0", optional = true }
 wasmparser = { version = "0.39.2", default-features = false }
 
+[target.'cfg(target_os = "windows")'.dependencies]
+winapi = { version = "0.3.7", features = ["winnt", "impl-default"] }
+
 [features]
 default = ["std"]
 std = ["cranelift-codegen/std", "cranelift-wasm/std", "wasmtime-environ/std", "wasmtime-debug/std", "wasmtime-runtime/std", "wasmparser/std"]

wasmtime-jit/src/code_memory.rs

@@ -1,16 +1,18 @@
 //! Memory management for executable code.
 
+use crate::function_table::FunctionTable;
 use alloc::boxed::Box;
 use alloc::string::String;
 use alloc::vec::Vec;
 use core::{cmp, mem};
 use region;
+use wasmtime_environ::{Compilation, CompiledFunction};
 use wasmtime_runtime::{Mmap, VMFunctionBody};
 
 /// Memory manager for executable code.
 pub struct CodeMemory {
-    current: Mmap,
+    current: (Mmap, FunctionTable),
-    mmaps: Vec<Mmap>,
+    mmaps: Vec<(Mmap, FunctionTable)>,
     position: usize,
     published: usize,
 }
@@ -19,30 +21,144 @@ impl CodeMemory {
     /// Create a new `CodeMemory` instance.
     pub fn new() -> Self {
         Self {
-            current: Mmap::new(),
+            current: (Mmap::new(), FunctionTable::new()),
             mmaps: Vec::new(),
             position: 0,
             published: 0,
         }
     }
 
+    /// Allocate a continuous memory block for a single compiled function.
+    /// TODO: Reorganize the code that calls this to emit code directly into the
+    /// mmap region rather than into a Vec that we need to copy in.
+    pub fn allocate_for_function(
+        &mut self,
+        func: &CompiledFunction,
+    ) -> Result<&mut [VMFunctionBody], String> {
+        let size = Self::function_allocation_size(func);
+
+        let start = self.position as u32;
+        let (buf, table) = self.allocate(size)?;
+
+        let (_, _, _, vmfunc) = Self::copy_function(func, start, buf, table);
+
+        Ok(vmfunc)
+    }
+
+    /// Allocate a continuous memory block for a compilation.
+    ///
+    /// Allocates memory for both the function bodies as well as function unwind data.
+    pub fn allocate_for_compilation(
+        &mut self,
+        compilation: &Compilation,
+    ) -> Result<Box<[&mut [VMFunctionBody]]>, String> {
+        let total_len = compilation
+            .into_iter()
+            .fold(0, |acc, func| acc + Self::function_allocation_size(func));
+
+        let mut start = self.position as u32;
+        let (mut buf, mut table) = self.allocate(total_len)?;
+        let mut result = Vec::with_capacity(compilation.len());
+
+        for func in compilation.into_iter() {
+            let (next_start, next_buf, next_table, vmfunc) =
+                Self::copy_function(func, start, buf, table);
+
+            result.push(vmfunc);
+
+            start = next_start;
+            buf = next_buf;
+            table = next_table;
+        }
+
+        Ok(result.into_boxed_slice())
+    }
+
+    /// Make all allocated memory executable.
+    pub fn publish(&mut self) {
+        self.push_current(0)
+            .expect("failed to push current memory map");
+
+        for (m, t) in &mut self.mmaps[self.published..] {
+            if m.len() != 0 {
+                unsafe {
+                    region::protect(m.as_mut_ptr(), m.len(), region::Protection::ReadExecute)
+                }
+                .expect("unable to make memory readonly and executable");
+            }
+
+            t.publish(m.as_ptr() as u64)
+                .expect("failed to publish function table");
+        }
+
+        self.published = self.mmaps.len();
+    }
+
     /// Allocate `size` bytes of memory which can be made executable later by
     /// calling `publish()`. Note that we allocate the memory as writeable so
     /// that it can be written to and patched, though we make it readonly before
     /// actually executing from it.
     ///
     /// TODO: Add an alignment flag.
-    fn allocate(&mut self, size: usize) -> Result<&mut [u8], String> {
+    fn allocate(&mut self, size: usize) -> Result<(&mut [u8], &mut FunctionTable), String> {
-        if self.current.len() - self.position < size {
+        if self.current.0.len() - self.position < size {
-            self.mmaps.push(mem::replace(
+            self.push_current(cmp::max(0x10000, size))?;
-                &mut self.current,
-                Mmap::with_at_least(cmp::max(0x10000, size))?,
-            ));
-            self.position = 0;
         }
+
         let old_position = self.position;
         self.position += size;
-        Ok(&mut self.current.as_mut_slice()[old_position..self.position])
+
+        Ok((
+            &mut self.current.0.as_mut_slice()[old_position..self.position],
+            &mut self.current.1,
+        ))
+    }
+
+    /// Calculates the allocation size of the given compiled function.
+    fn function_allocation_size(func: &CompiledFunction) -> usize {
+        if func.unwind_info.is_empty() {
+            func.body.len()
+        } else {
+            // Account for necessary unwind information alignment padding (32-bit)
+            ((func.body.len() + 3) & !3) + func.unwind_info.len()
+        }
+    }
+
+    /// Copies the data of the compiled function to the given buffer.
+    ///
+    /// This will also add the function to the current function table.
+    fn copy_function<'a>(
+        func: &CompiledFunction,
+        func_start: u32,
+        buf: &'a mut [u8],
+        table: &'a mut FunctionTable,
+    ) -> (
+        u32,
+        &'a mut [u8],
+        &'a mut FunctionTable,
+        &'a mut [VMFunctionBody],
+    ) {
+        let func_end = func_start + (func.body.len() as u32);
+
+        let (body, remainder) = buf.split_at_mut(func.body.len());
+        body.copy_from_slice(&func.body);
+        let vmfunc = Self::view_as_mut_vmfunc_slice(body);
+
+        if func.unwind_info.is_empty() {
+            return (func_end, remainder, table, vmfunc);
+        }
+
+        // Keep unwind information 32-bit aligned (round up to the nearest 4 byte boundary)
+        let padding = ((func.body.len() + 3) & !3) - func.body.len();
+        let (unwind, remainder) = remainder.split_at_mut(padding + func.unwind_info.len());
+        unwind[padding..].copy_from_slice(&func.unwind_info);
+
+        let unwind_start = func_end + (padding as u32);
+        let unwind_end = unwind_start + (func.unwind_info.len() as u32);
+
+        table.add_function(func_start, func_end, unwind_start);
+
+        (unwind_end, remainder, table, vmfunc)
     }
 
     /// Convert mut a slice from u8 to VMFunctionBody.
@@ -52,51 +168,28 @@ impl CodeMemory {
         unsafe { &mut *body_ptr }
     }
 
-    /// Allocate enough memory to hold a copy of `slice` and copy the data into it.
+    /// Pushes the current Mmap (and function table) and allocates a new Mmap of the given size.
-    /// TODO: Reorganize the code that calls this to emit code directly into the
+    fn push_current(&mut self, new_size: usize) -> Result<(), String> {
-    /// mmap region rather than into a Vec that we need to copy in.
+        let previous = mem::replace(
-    pub fn allocate_copy_of_byte_slice(
+            &mut self.current,
-        &mut self,
+            (
-        slice: &[u8],
+                if new_size == 0 {
-    ) -> Result<&mut [VMFunctionBody], String> {
+                    Mmap::new()
-        let new = self.allocate(slice.len())?;
+                } else {
-        new.copy_from_slice(slice);
+                    Mmap::with_at_least(cmp::max(0x10000, new_size))?
-        Ok(Self::view_as_mut_vmfunc_slice(new))
+                },
+                FunctionTable::new(),
+            ),
+        );
+
+        if previous.0.len() > 0 {
+            self.mmaps.push(previous);
+        } else {
+            assert!(previous.1.len() == 0);
         }
 
-    /// Allocate enough continuous memory block for multiple code blocks. See also
-    /// allocate_copy_of_byte_slice.
-    pub fn allocate_copy_of_byte_slices(
-        &mut self,
-        slices: &[&[u8]],
-    ) -> Result<Box<[&mut [VMFunctionBody]]>, String> {
-        let total_len = slices.into_iter().fold(0, |acc, slice| acc + slice.len());
-        let new = self.allocate(total_len)?;
-        let mut tail = new;
-        let mut result = Vec::with_capacity(slices.len());
-        for slice in slices {
-            let (block, next_tail) = tail.split_at_mut(slice.len());
-            block.copy_from_slice(slice);
-            tail = next_tail;
-            result.push(Self::view_as_mut_vmfunc_slice(block));
-        }
-        Ok(result.into_boxed_slice())
-    }
-
-    /// Make all allocated memory executable.
-    pub fn publish(&mut self) {
-        self.mmaps
-            .push(mem::replace(&mut self.current, Mmap::new()));
         self.position = 0;
 
-        for m in &mut self.mmaps[self.published..] {
+        Ok(())
-            if m.len() != 0 {
-                unsafe {
-                    region::protect(m.as_mut_ptr(), m.len(), region::Protection::ReadExecute)
-                }
-                .expect("unable to make memory readonly and executable");
-            }
-        }
-        self.published = self.mmaps.len();
     }
 }

wasmtime-jit/src/compiler.rs

@@ -17,8 +17,8 @@ use cranelift_frontend::{FunctionBuilder, FunctionBuilderContext};
 use cranelift_wasm::{DefinedFuncIndex, DefinedMemoryIndex, ModuleTranslationState};
 use wasmtime_debug::{emit_debugsections_image, DebugInfoData};
 use wasmtime_environ::{
-    Compilation, CompileError, Compiler as _C, FunctionBodyData, Module, ModuleVmctxInfo,
+    Compilation, CompileError, CompiledFunction, Compiler as _C, FunctionBodyData, Module,
-    Relocations, Traps, Tunables, VMOffsets,
+    ModuleVmctxInfo, Relocations, Traps, Tunables, VMOffsets,
 };
 use wasmtime_runtime::{
     get_mut_trap_registry, InstantiationError, SignatureRegistry, TrapRegistrationGuard,
@@ -323,7 +323,8 @@ fn make_trampoline(
         builder.finalize()
     }
 
-    let mut code_buf: Vec<u8> = Vec::new();
+    let mut code_buf = Vec::new();
+    let mut unwind_info = Vec::new();
     let mut reloc_sink = RelocSink {};
     let mut trap_sink = binemit::NullTrapSink {};
     let mut stackmap_sink = binemit::NullStackmapSink {};
@@ -337,8 +338,14 @@ fn make_trampoline(
         )
         .map_err(|error| SetupError::Compile(CompileError::Codegen(error)))?;
 
+    context.emit_unwind_info(isa, &mut unwind_info);
+
     Ok(code_memory
-        .allocate_copy_of_byte_slice(&code_buf)
+        .allocate_for_function(&CompiledFunction {
+            body: code_buf,
+            jt_offsets: context.func.jt_offsets,
+            unwind_info,
+        })
         .map_err(|message| SetupError::Instantiate(InstantiationError::Resource(message)))?
         .as_ptr())
 }
@@ -347,14 +354,8 @@ fn allocate_functions(
     code_memory: &mut CodeMemory,
     compilation: &Compilation,
 ) -> Result<PrimaryMap<DefinedFuncIndex, *mut [VMFunctionBody]>, String> {
-    // Allocate code for all function in one continuous memory block.
+    let fat_ptrs = code_memory.allocate_for_compilation(compilation)?;
-    // First, collect all function bodies into vector to pass to the
+
-    // allocate_copy_of_byte_slices.
-    let bodies = compilation
-        .into_iter()
-        .map(|code_and_jt| &code_and_jt.body[..])
-        .collect::<Vec<&[u8]>>();
-    let fat_ptrs = code_memory.allocate_copy_of_byte_slices(&bodies)?;
     // Second, create a PrimaryMap from result vector of pointers.
     let mut result = PrimaryMap::with_capacity(compilation.len());
     for i in 0..fat_ptrs.len() {

wasmtime-jit/src/function_table.rs

@@ -0,0 +1,134 @@
+//! Runtime function table.
+//!
+//! This module is primarily used to track JIT functions on Windows for stack walking and unwind.
+
+/// Represents a runtime function table.
+///
+/// The runtime function table is not implemented for non-Windows target platforms.
+#[cfg(not(target_os = "windows"))]
+pub(crate) struct FunctionTable;
+
+#[cfg(not(target_os = "windows"))]
+impl FunctionTable {
+    /// Creates a new function table.
+    pub fn new() -> Self {
+        Self
+    }
+
+    /// Returns the number of functions in the table, also referred to as its 'length'.
+    ///
+    /// For non-Windows platforms, the table will always be empty.
+    pub fn len(&self) -> usize {
+        0
+    }
+
+    /// Adds a function to the table based off of the start offset, end offset, and unwind offset.
+    ///
+    /// The offsets are from the "module base", which is provided when the table is published.
+    ///
+    /// For non-Windows platforms, this is a no-op.
+    pub fn add_function(&mut self, _start: u32, _end: u32, _unwind: u32) {}
+
+    /// Publishes the function table using the given base address.
+    ///
+    /// A published function table will automatically be deleted when it is dropped.
+    ///
+    /// For non-Windows platforms, this is a no-op.
+    pub fn publish(&mut self, _base_address: u64) -> Result<(), String> {
+        Ok(())
+    }
+}
+
+/// Represents a runtime function table.
+///
+/// This is used to register JIT code with the operating system to enable stack walking and unwinding.
+#[cfg(all(target_os = "windows", target_arch = "x86_64"))]
+pub(crate) struct FunctionTable {
+    functions: Vec<winapi::um::winnt::RUNTIME_FUNCTION>,
+    published: bool,
+}
+
+#[cfg(all(target_os = "windows", target_arch = "x86_64"))]
+impl FunctionTable {
+    /// Creates a new function table.
+    pub fn new() -> Self {
+        Self {
+            functions: Vec::new(),
+            published: false,
+        }
+    }
+
+    /// Returns the number of functions in the table, also referred to as its 'length'.
+    pub fn len(&self) -> usize {
+        self.functions.len()
+    }
+
+    /// Adds a function to the table based off of the start offset, end offset, and unwind offset.
+    ///
+    /// The offsets are from the "module base", which is provided when the table is published.
+    pub fn add_function(&mut self, start: u32, end: u32, unwind: u32) {
+        use winapi::um::winnt;
+
+        assert!(!self.published, "table has already been published");
+
+        let mut entry = winnt::RUNTIME_FUNCTION::default();
+
+        entry.BeginAddress = start;
+        entry.EndAddress = end;
+
+        unsafe {
+            *entry.u.UnwindInfoAddress_mut() = unwind;
+        }
+
+        self.functions.push(entry);
+    }
+
+    /// Publishes the function table using the given base address.
+    ///
+    /// A published function table will automatically be deleted when it is dropped.
+    pub fn publish(&mut self, base_address: u64) -> Result<(), String> {
+        use winapi::um::winnt;
+
+        if self.published {
+            return Err("function table was already published".into());
+        }
+
+        self.published = true;
+
+        if self.functions.is_empty() {
+            return Ok(());
+        }
+
+        unsafe {
+            // Windows heap allocations are 32-bit aligned, but assert just in case
+            assert!(
+                (self.functions.as_mut_ptr() as u64) % 4 == 0,
+                "function table allocation was not aligned"
+            );
+
+            if winnt::RtlAddFunctionTable(
+                self.functions.as_mut_ptr(),
+                self.functions.len() as u32,
+                base_address,
+            ) == 0
+            {
+                return Err("failed to add function table".into());
+            }
+        }
+
+        Ok(())
+    }
+}
+
+#[cfg(target_os = "windows")]
+impl Drop for FunctionTable {
+    fn drop(&mut self) {
+        use winapi::um::winnt;
+
+        if self.published {
+            unsafe {
+                winnt::RtlDeleteFunctionTable(self.functions.as_mut_ptr());
+            }
+        }
+    }
+}

wasmtime-jit/src/lib.rs

@@ -34,6 +34,7 @@ mod action;
 mod code_memory;
 mod compiler;
 mod context;
+mod function_table;
 mod instantiate;
 mod link;
 mod namespace;

wasmtime-runtime/signalhandlers/SignalHandlers.cpp

@@ -404,7 +404,7 @@ static
 __attribute__ ((warn_unused_result))
 #endif
 bool
-HandleTrap(CONTEXT* context)
+HandleTrap(CONTEXT* context, bool reset_guard_page)
 {
     assert(sAlreadyHandlingTrap);
 
@@ -412,7 +412,7 @@ HandleTrap(CONTEXT* context)
         return false;
     }
 
-    RecordTrap(ContextToPC(context));
+    RecordTrap(ContextToPC(context), reset_guard_page);
 
     // Unwind calls longjmp, so it doesn't run the automatic
     // sAlreadhHanldingTrap cleanups, so reset it manually before doing
@@ -467,7 +467,8 @@ WasmTrapHandler(LPEXCEPTION_POINTERS exception)
         return EXCEPTION_CONTINUE_SEARCH;
     }
 
-    if (!HandleTrap(exception->ContextRecord)) {
+    if (!HandleTrap(exception->ContextRecord,
+                    record->ExceptionCode == EXCEPTION_STACK_OVERFLOW)) {
         return EXCEPTION_CONTINUE_SEARCH;
     }
 
@@ -549,7 +550,7 @@ HandleMachException(const ExceptionRequest& request)
 
     {
         AutoHandlingTrap aht;
-        if (!HandleTrap(&context)) {
+        if (!HandleTrap(&context, false)) {
             return false;
         }
     }
@@ -632,7 +633,7 @@ WasmTrapHandler(int signum, siginfo_t* info, void* context)
     if (!sAlreadyHandlingTrap) {
         AutoHandlingTrap aht;
         assert(signum == SIGSEGV || signum == SIGBUS || signum == SIGFPE || signum == SIGILL);
-        if (HandleTrap(static_cast<CONTEXT*>(context))) {
+        if (HandleTrap(static_cast<CONTEXT*>(context), false)) {
             return;
         }
     }

wasmtime-runtime/signalhandlers/SignalHandlers.hpp

@@ -13,7 +13,7 @@ extern "C" {
 
 int8_t CheckIfTrapAtAddress(const uint8_t* pc);
 // Record the Trap code and wasm bytecode offset in TLS somewhere
-void RecordTrap(const uint8_t* pc);
+void RecordTrap(const uint8_t* pc, bool reset_guard_page);
 
 void* EnterScope(void*);
 void LeaveScope(void*);

wasmtime-runtime/src/traphandlers.rs

@@ -21,6 +21,7 @@ extern "C" {
 thread_local! {
     static RECORDED_TRAP: Cell<Option<TrapDescription>> = Cell::new(None);
     static JMP_BUF: Cell<*const u8> = Cell::new(ptr::null());
+    static RESET_GUARD_PAGE: Cell<bool> = Cell::new(false);
 }
 
 /// Check if there is a trap at given PC
@@ -40,7 +41,7 @@ pub extern "C" fn CheckIfTrapAtAddress(_pc: *const u8) -> i8 {
 #[doc(hidden)]
 #[allow(non_snake_case)]
 #[no_mangle]
-pub extern "C" fn RecordTrap(pc: *const u8) {
+pub extern "C" fn RecordTrap(pc: *const u8, reset_guard_page: bool) {
     // TODO: please see explanation in CheckIfTrapAtAddress.
     let registry = get_trap_registry();
     let trap_desc = registry
@@ -49,6 +50,11 @@ pub extern "C" fn RecordTrap(pc: *const u8) {
             source_loc: ir::SourceLoc::default(),
             trap_code: ir::TrapCode::StackOverflow,
         });
+
+    if reset_guard_page {
+        RESET_GUARD_PAGE.with(|v| v.set(true));
+    }
+
     RECORDED_TRAP.with(|data| {
         assert_eq!(
             data.get(),
@@ -77,9 +83,32 @@ pub extern "C" fn GetScope() -> *const u8 {
 #[allow(non_snake_case)]
 #[no_mangle]
 pub extern "C" fn LeaveScope(ptr: *const u8) {
+    RESET_GUARD_PAGE.with(|v| {
+        if v.get() {
+            reset_guard_page();
+            v.set(false);
+        }
+    });
+
     JMP_BUF.with(|buf| buf.set(ptr))
 }
 
+#[cfg(target_os = "windows")]
+fn reset_guard_page() {
+    extern "C" {
+        fn _resetstkoflw() -> winapi::ctypes::c_int;
+    }
+
+    // We need to restore guard page under stack to handle future stack overflows properly.
+    // https://docs.microsoft.com/en-us/cpp/c-runtime-library/reference/resetstkoflw?view=vs-2019
+    if unsafe { _resetstkoflw() } == 0 {
+        panic!("failed to restore stack guard page");
+    }
+}
+
+#[cfg(not(target_os = "windows"))]
+fn reset_guard_page() {}
+
 fn trap_message() -> String {
     let trap_desc = RECORDED_TRAP
         .with(|data| data.replace(None))