v1.5.0

Related to https://github.com/extism/python-sdk/issues/23 - there is
currently no way to get the length of the error message, so we need to
make sure it is a valid C string.

kernel/.gitignore

@@ -1,3 +0,0 @@
-owi-out
-*.wat
-proofs

kernel/Cargo.toml

@@ -7,7 +7,6 @@ edition = "2021"
 
 [dev-dependencies]
 wasm-bindgen-test = "0.3.39"
-owi = {git = "https://github.com/dylibso/owi-rs"}
 
 [features]
 default = ["bounds-checking"]
@@ -16,4 +15,4 @@ bounds-checking = []
 [workspace]
 members = [
   "."
-]
+]

kernel/build.sh

@@ -1,7 +1,5 @@
 #!/usr/bin/env bash
 
-set -e
-
 export CARGO_FLAGS=""
 
 while getopts d flag

kernel/examples/alloc_length.rs

@@ -1,21 +0,0 @@
-#![no_main]
-#![no_std]
-use extism_runtime_kernel::*;
-use owi::*;
-
-main!({
-    let n = alloc(1024);
-
-    let x = u64();
-    assume(x > 0);
-
-    let m = alloc(x);
-
-    // 1. Length should equal `x` while active
-    assert(length(m) == x);
-
-    // 2. Length should equal `0` after free
-    free(m); // Free the block
-    assert(length(m) == 0);
-    free(n);
-});

kernel/examples/error.rs

@@ -1,24 +0,0 @@
-#![no_main]
-#![no_std]
-use extism_runtime_kernel::*;
-use owi::*;
-
-main!({
-    let x = u64();
-    let n = u64();
-    let m = u64();
-    assume(x > 0);
-    assume(n > 0);
-    assume(m > 0);
-
-    alloc(n);
-    alloc(m);
-    let n = alloc(x);
-    assert(error_get() == 0);
-
-    error_set(n);
-    assert(error_get() == n);
-    alloc(m);
-    error_set(0);
-    assert(error_get() == 0);
-});

kernel/examples/load_store.rs

@@ -1,17 +0,0 @@
-#![no_main]
-#![no_std]
-use extism_runtime_kernel::*;
-use owi::*;
-
-main!({
-    let x = u64();
-    assume(x > 0);
-
-    let m = alloc(x);
-    assert(length(m) == x);
-    for i in 0..x {
-        store_u8(m + i, i as u8);
-        assert(load_u8(m + i) == i as u8);
-    }
-    free(m);
-});

kernel/examples/reuse.rs

@@ -1,39 +0,0 @@
-#![no_main]
-#![no_std]
-use extism_runtime_kernel::*;
-use owi::*;
-
-main!({
-    let x = u64();
-    assume(x > 0);
-
-    let y = u64();
-    assume(y > 0);
-
-    let mut tmp = 0;
-
-    for _ in 0..y {
-        let m = alloc(x);
-        if tmp == 0 {
-            tmp = m;
-        } else {
-            // Check that the existing block is being re-used
-            assert(m == tmp);
-        }
-
-        assert(length(m) == x);
-        free(m); // Free the block
-    }
-
-    let y = u64();
-    assume(y == x + 1);
-    let n = alloc(y);
-    assert(n > tmp);
-
-    let z = u64();
-    assume(z <= x);
-    assume(x - z < 32);
-    assume(z > 0);
-    let p = alloc(z);
-    assert(p == tmp);
-});

kernel/src/bin/extism-runtime.rs

@@ -1,5 +1,5 @@
-#![no_std]
 #![no_main]
+#![no_std]
 
 pub use extism_runtime_kernel::*;
 

kernel/src/lib.rs

@@ -175,7 +175,7 @@ impl MemoryRoot {
         core::ptr::write_bytes(
             self.blocks.as_mut_ptr() as *mut u8,
             MemoryStatus::Unused as u8,
-            self_position as usize - core::mem::size_of::<MemoryRoot>(),
+            self_position as usize,
         );
 
         // Clear extism runtime metadata
@@ -546,7 +546,8 @@ pub unsafe fn reset() {
     MemoryRoot::new().reset()
 }
 
-/// Set the error message offset
+/// Set the error message offset, the handle passed to this
+/// function should not be freed after this call
 #[no_mangle]
 pub unsafe fn error_set(h: Handle) {
     let root = MemoryRoot::new();
@@ -638,15 +639,4 @@ mod test {
 
         assert_eq!(last, 0);
     }
-
-    #[wasm_bindgen_test]
-    fn test_sym() {
-        unsafe {
-            reset();
-            let a = alloc(47);
-            let b = alloc(20);
-            assert_eq!(length(a), 47);
-            assert_eq!(length(b), 20);
-        }
-    }
 }

kernel/verify.sh

@@ -1,23 +0,0 @@
-#!/usr/bin/env bash
-
-set -e
-
-OUT_DIR=./target/wasm32-unknown-unknown/release/examples/
-get_proof() {
-   cp "$OUT_DIR/$1.wasm" "./proofs/$1.wasm"
-}
-
-cargo build --examples --release --target wasm32-unknown-unknown --no-default-features
-
-mkdir -p proofs
-get_proof alloc_length
-get_proof load_store
-get_proof reuse
-get_proof error
-
-for proof in $(ls proofs/*.wasm); do
-  echo "Checking $proof"
-  owi  conc "$proof" $@
-  echo
-  echo "---"
-done

runtime/Cargo.toml

@@ -9,8 +9,8 @@ repository.workspace = true
 version.workspace = true
 
 [dependencies]
-wasmtime = ">= 20.0.0, < 22.0.0"
-wasi-common = ">= 20.0.0, < 22.0.0"
+wasmtime = ">= 20.0.0, < 23.0.0"
+wasi-common = ">= 20.0.0, < 23.0.0"
 anyhow = "1"
 serde = {version = "1", features = ["derive"]}
 serde_json = "1"

runtime/README.md

@@ -12,7 +12,7 @@ To use the `extism` crate, you can add it to your Cargo file:
 
 ```toml
 [dependencies]
-extism = "1.2.0"
+extism = "1.4.1"
 ```
 
 ## Environment variables

runtime/benches/bench.rs

@@ -35,6 +35,21 @@ pub fn create_plugin(c: &mut Criterion) {
     });
 }
 
+pub fn create_plugin_no_cache(c: &mut Criterion) {
+    let mut g = c.benchmark_group("create");
+    g.noise_threshold(1.0);
+    g.significance_level(0.2);
+    g.bench_function("create_plugin_no_cache", |b| {
+        b.iter(|| {
+            let _plugin = PluginBuilder::new(COUNT_VOWELS)
+                .with_cache_disabled()
+                .with_wasi(true)
+                .build()
+                .unwrap();
+        })
+    });
+}
+
 #[derive(Debug, serde::Deserialize, PartialEq)]
 struct Count {
     count: u32,
@@ -251,6 +266,7 @@ criterion_group!(
     reflect_linked,
     basic,
     create_plugin,
+    create_plugin_no_cache,
     count_vowels
 );
 criterion_main!(benches);

runtime/src/function.rs

@@ -279,7 +279,7 @@ impl Function {
 /// For example, the following defines a host function named `add_newline` that takes a
 /// string parameter and returns a string result:
 /// ```rust
-/// extism::host_fn!(add_newline(_user_data: (), a: String) -> String { Ok(a + "\n") });
+/// extism::host_fn!(add_newline(_user_data: (); a: String) -> String { Ok(a + "\n") });
 /// ```
 /// A few things worth noting:
 /// - The function always returns a `Result` that wraps the specified return type

runtime/src/plugin.rs

@@ -81,6 +81,8 @@ pub struct Plugin {
     pub(crate) store_needs_reset: bool,
 
     pub(crate) debug_options: DebugOptions,
+
+    pub(crate) error_msg: Option<Vec<u8>>,
 }
 
 unsafe impl Send for Plugin {}
@@ -361,6 +363,7 @@ impl Plugin {
             store_needs_reset: false,
             debug_options,
             _functions: imports,
+            error_msg: None,
         };
 
         plugin.current_plugin_mut().store = &mut plugin.store;

runtime/src/sdk.rs

@@ -505,6 +505,8 @@ pub unsafe extern "C" fn extism_plugin_call_with_host_context(
     let lock = plugin.instance.clone();
     let mut lock = lock.lock().unwrap();
 
+    plugin.error_msg = None;
+
     // Get function name
     let name = std::ffi::CStr::from_ptr(func_name);
     let name = match name.to_str() {
@@ -551,10 +553,19 @@ pub unsafe extern "C" fn extism_plugin_error(plugin: *mut Plugin) -> *const c_ch
         return std::ptr::null();
     }
 
-    plugin
+    let offs = plugin.output.error_offset;
+
+    let ptr = plugin.current_plugin_mut().memory_ptr().add(offs as usize) as *const _;
+
+    let len = plugin
         .current_plugin_mut()
-        .memory_ptr()
-        .add(plugin.output.error_offset as usize) as *const _
+        .memory_length(offs)
+        .unwrap_or_default();
+
+    let mut data = std::slice::from_raw_parts(ptr, len as usize).to_vec();
+    data.push(0);
+    plugin.error_msg = Some(data);
+    plugin.error_msg.as_ref().unwrap().as_ptr() as *const _
 }
 
 /// Get the length of a plugin's output data