Removed uint8view() from the memory API and redundant FunctionEnv in …

…tests

examples/engine_headless.rs

@@ -96,7 +96,6 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
         // We create a headless Universal engine.
         let engine = EngineBuilder::headless();
         let mut store = Store::new(engine);
-        let _env = FunctionEnv::new(&mut store, ());
 
         println!("Deserializing module...");
         // Here we go.

examples/errors.rs

@@ -39,7 +39,6 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     // the default provided by Wasmer.
     // You can use `Store::default()` for that.
     let mut store = Store::new(Cranelift::default());
-    let _env = FunctionEnv::new(&mut store, ());
 
     println!("Compiling module...");
     // Let's compile the Wasm module.

examples/exports_function.rs

@@ -40,7 +40,6 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     // the default provided by Wasmer.
     // You can use `Store::default()` for that.
     let mut store = Store::new(Cranelift::default());
-    let _env = FunctionEnv::new(&mut store, ());
 
     println!("Compiling module...");
     // Let's compile the Wasm module.

examples/exports_global.rs

@@ -40,7 +40,6 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     // the default provided by Wasmer.
     // You can use `Store::default()` for that.
     let mut store = Store::new(Cranelift::default());
-    let _env = FunctionEnv::new(&mut store, ());
 
     println!("Compiling module...");
     // Let's compile the Wasm module.

examples/exports_memory.rs

@@ -37,7 +37,6 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     // the default provided by Wasmer.
     // You can use `Store::default()` for that.
     let mut store = Store::new(Cranelift::default());
-    let _env = FunctionEnv::new(&mut store, ());
 
     println!("Compiling module...");
     // Let's compile the Wasm module.

examples/features.rs

@@ -41,7 +41,6 @@ fn main() -> anyhow::Result<()> {
 
     // Now, let's define the store, and compile the module.
     let mut store = Store::new(engine);
-    let _env = FunctionEnv::new(&mut store, ());
     let module = Module::new(&store, wasm_bytes)?;
 
     // Finally, let's instantiate the module, and execute something

examples/imports_global.rs

@@ -40,7 +40,6 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     // the default provided by Wasmer.
     // You can use `Store::default()` for that.
     let mut store = Store::new(Cranelift::default());
-    let _env = FunctionEnv::new(&mut store, ());
 
     println!("Compiling module...");
     // Let's compile the Wasm module.

examples/instance.rs

@@ -39,7 +39,6 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     // the default provided by Wasmer.
     // You can use `Store::default()` for that.
     let mut store = Store::new(Cranelift::default());
-    let _env = FunctionEnv::new(&mut store, ());
 
     println!("Compiling module...");
     // Let's compile the Wasm module.

examples/memory.rs

@@ -59,7 +59,6 @@ fn main() -> anyhow::Result<()> {
     // the default provided by Wasmer.
     // You can use `Store::default()` for that.
     let mut store = Store::new(Cranelift::default());
-    let _env = FunctionEnv::new(&mut store, ());
 
     println!("Compiling module...");
     // Let's compile the Wasm module.

examples/metering.rs

@@ -72,7 +72,6 @@ fn main() -> anyhow::Result<()> {
     // We use our previously create compiler configuration
     // with the Universal engine.
     let mut store = Store::new(EngineBuilder::new(compiler_config));
-    let _env = FunctionEnv::new(&mut store, ());
 
     println!("Compiling module...");
     // Let's compile the Wasm module.

examples/tunables_limit_memory.rs

@@ -143,7 +143,6 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
 
     // Create a store, that holds the engine and our custom tunables
     let mut store = Store::new_with_tunables(compiler, tunables);
-    let _env = FunctionEnv::new(&mut store, ());
 
     println!("Compiling module...");
     let module = Module::new(&store, wasm_bytes)?;

lib/api/Cargo.toml

@@ -26,9 +26,9 @@ indexmap = { version = "1.6", features = ["serde-1"] }
 cfg-if = "1.0"
 thiserror = "1.0"
 more-asserts = "0.2"
-tracing = "0.1"
 # - Optional shared dependencies.
 wat = { version = "1.0", optional = true }
+tracing = { version = "0.1", optional = true }
 
 # Dependencies and Development Dependencies for `sys`.
 [target.'cfg(not(target_arch = "wasm32"))'.dependencies]

lib/api/src/js/externals/memory.rs

@@ -7,6 +7,7 @@ use std::marker::PhantomData;
 use std::mem::MaybeUninit;
 use std::slice;
 use thiserror::Error;
+#[cfg(feature = "tracing")]
 use tracing::warn;
 
 use wasm_bindgen::prelude::*;
@@ -177,7 +178,6 @@ impl Memory {
         IntoPages: Into<Pages>,
     {
         let pages = delta.into();
-        warn!("memory grow {}", pages.0);
         let js_memory = &self.handle.get_mut(store.objects_mut()).memory;
         let our_js_memory: &JSMemory = JsCast::unchecked_from_js_ref(js_memory);
         let new_pages = our_js_memory.grow(pages.0).map_err(|err| {
@@ -239,6 +239,7 @@ impl<'a> MemoryBuffer<'a> {
             .ok_or(MemoryAccessError::Overflow)?;
         let view = unsafe { &*(self.base) };
         if end > view.length().into() {
+            #[cfg(feature = "tracing")]
             warn!("attempted to read ({} bytes) beyond the bounds of the memory view ({} > {})", buf.len(), end, view.length());
             return Err(MemoryAccessError::HeapOutOfBounds);
         }
@@ -257,6 +258,7 @@ impl<'a> MemoryBuffer<'a> {
             .ok_or(MemoryAccessError::Overflow)?;
         let view = unsafe { &*(self.base) };
         if end > view.length().into() {
+            #[cfg(feature = "tracing")]
             warn!("attempted to read ({} bytes) beyond the bounds of the memory view ({} > {})", buf.len(), end, view.length());
             return Err(MemoryAccessError::HeapOutOfBounds);
         }
@@ -273,6 +275,7 @@ impl<'a> MemoryBuffer<'a> {
             .ok_or(MemoryAccessError::Overflow)?;
         let view = unsafe { &mut *(self.base) };
         if end > view.length().into() {
+            #[cfg(feature = "tracing")]
             warn!("attempted to write ({} bytes) beyond the bounds of the memory view ({} > {})", data.len(), end, view.length());
             return Err(MemoryAccessError::HeapOutOfBounds);
         }

lib/api/src/js/externals/memory_view.rs

@@ -4,6 +4,7 @@ use std::convert::TryInto;
 use std::marker::PhantomData;
 use std::mem::MaybeUninit;
 use std::slice;
+#[cfg(feature = "tracing")]
 use tracing::warn;
 
 use wasmer_types::{Bytes, Pages};
@@ -79,12 +80,6 @@ impl<'a> MemoryView<'a>
         Bytes(self.size as usize).try_into().unwrap()
     }
 
-    /// Used by tests
-    #[doc(hidden)]
-    pub fn uint8view(&self) -> js_sys::Uint8Array {
-        self.view.clone()
-    }
-
     pub(crate) fn buffer(&self) -> MemoryBuffer<'a> {
         MemoryBuffer {
             base: &self.view as *const _ as *mut _,
@@ -112,13 +107,32 @@ impl<'a> MemoryView<'a>
             .map_err(|_| MemoryAccessError::Overflow)?;
         let end = offset.checked_add(len).ok_or(MemoryAccessError::Overflow)?;
         if end > view.length() {
+            #[cfg(feature = "tracing")]
             warn!("attempted to read ({} bytes) beyond the bounds of the memory view ({} > {})", len, end, view.length());
             Err(MemoryAccessError::HeapOutOfBounds)?;
         }
         view.subarray(offset, end).copy_to(data);
         Ok(())
     }
 
+    /// Safely reads a single byte from memory at the given offset
+    ///
+    /// This method is guaranteed to be safe (from the host side) in the face of
+    /// concurrent writes.
+    pub fn read_u8(
+        &self,
+        offset: u64
+    ) -> Result<u8, MemoryAccessError> {
+        let view = &self.view;
+        let offset: u32 = offset.try_into().map_err(|_| MemoryAccessError::Overflow)?;
+        if offset >= view.length() {
+            #[cfg(feature = "tracing")]
+            warn!("attempted to read beyond the bounds of the memory view ({} >= {})", offset, view.length());
+            Err(MemoryAccessError::HeapOutOfBounds)?;
+        }
+        Ok(view.get_index(offset))
+    }
+
     /// Safely reads bytes from the memory at the given offset.
     ///
     /// This method is similar to `read` but allows reading into an
@@ -142,6 +156,7 @@ impl<'a> MemoryView<'a>
             .map_err(|_| MemoryAccessError::Overflow)?;
         let end = offset.checked_add(len).ok_or(MemoryAccessError::Overflow)?;
         if end > view.length() {
+            #[cfg(feature = "tracing")]
             warn!("attempted to read ({} bytes) beyond the bounds of the memory view ({} > {})", len, end, view.length());
             Err(MemoryAccessError::HeapOutOfBounds)?;
         }
@@ -177,10 +192,31 @@ impl<'a> MemoryView<'a>
         let view = &self.view;
         let end = offset.checked_add(len).ok_or(MemoryAccessError::Overflow)?;
         if end > view.length() {
+            #[cfg(feature = "tracing")]
             warn!("attempted to write ({} bytes) beyond the bounds of the memory view ({} > {})", len, end, view.length());
             Err(MemoryAccessError::HeapOutOfBounds)?;
         }
         view.subarray(offset, end).copy_from(data);
         Ok(())
     }
+
+    /// Safely reads a single byte from memory at the given offset
+    ///
+    /// This method is guaranteed to be safe (from the host side) in the face of
+    /// concurrent writes.
+    pub fn write_u8(
+        &self,
+        offset: u64,
+        val: u8
+    ) -> Result<(), MemoryAccessError> {
+        let view = &self.view;
+        let offset: u32 = offset.try_into().map_err(|_| MemoryAccessError::Overflow)?;
+        if offset >= view.length() {
+            #[cfg(feature = "tracing")]
+            warn!("attempted to write beyond the bounds of the memory view ({} >= {})", offset, view.length());
+            Err(MemoryAccessError::HeapOutOfBounds)?;
+        }
+        view.set_index(offset, val);
+        Ok(())
+    }
 }

lib/api/src/sys/externals/memory.rs

@@ -8,6 +8,7 @@ use std::marker::PhantomData;
 use std::mem;
 use std::mem::MaybeUninit;
 use std::slice;
+#[cfg(feature = "tracing")]
 use tracing::warn;
 use wasmer_types::Pages;
 use wasmer_vm::{InternalStoreHandle, MemoryError, StoreHandle, StoreObjects, VMExtern, VMMemory};
@@ -177,6 +178,7 @@ impl<'a> MemoryBuffer<'a> {
             .checked_add(buf.len() as u64)
             .ok_or(MemoryAccessError::Overflow)?;
         if end > self.len.try_into().unwrap() {
+            #[cfg(feature = "tracing")]
             warn!("attempted to read ({} bytes) beyond the bounds of the memory view ({} > {})", buf.len(), end, self.len);
             return Err(MemoryAccessError::HeapOutOfBounds);
         }
@@ -195,6 +197,7 @@ impl<'a> MemoryBuffer<'a> {
             .checked_add(buf.len() as u64)
             .ok_or(MemoryAccessError::Overflow)?;
         if end > self.len.try_into().unwrap() {
+            #[cfg(feature = "tracing")]
             warn!("attempted to read ({} bytes) beyond the bounds of the memory view ({} > {})", buf.len(), end, self.len);
             return Err(MemoryAccessError::HeapOutOfBounds);
         }
@@ -211,6 +214,7 @@ impl<'a> MemoryBuffer<'a> {
             .checked_add(data.len() as u64)
             .ok_or(MemoryAccessError::Overflow)?;
         if end > self.len.try_into().unwrap() {
+            #[cfg(feature = "tracing")]
             warn!("attempted to write ({} bytes) beyond the bounds of the memory view ({} > {})", data.len(), end, self.len);
             return Err(MemoryAccessError::HeapOutOfBounds);
         }

lib/api/src/sys/externals/memory_view.rs

@@ -115,6 +115,19 @@ impl<'a> MemoryView<'a>
         self.buffer.read(offset, buf)
     }
 
+    /// Safely reads a single byte from memory at the given offset
+    ///
+    /// This method is guaranteed to be safe (from the host side) in the face of
+    /// concurrent writes.
+    pub fn read_u8(
+        &self,
+        offset: u64
+    ) -> Result<u8, MemoryAccessError> {
+        let mut buf = [0u8; 1];
+        self.read(offset, &mut buf)?;
+        Ok(buf[0])
+    }
+
     /// Safely reads bytes from the memory at the given offset.
     ///
     /// This method is similar to `read` but allows reading into an
@@ -147,4 +160,18 @@ impl<'a> MemoryView<'a>
     ) -> Result<(), MemoryAccessError> {
         self.buffer.write(offset, data)
     }
+
+    /// Safely reads a single byte from memory at the given offset
+    ///
+    /// This method is guaranteed to be safe (from the host side) in the face of
+    /// concurrent writes.
+    pub fn write_u8(
+        &self,
+        offset: u64,
+        val: u8
+    ) -> Result<(), MemoryAccessError> {
+        let buf = [ val ];
+        self.write(offset, &buf)?;
+        Ok(())
+    }
 }

lib/api/tests/js_externals.rs

@@ -6,7 +6,6 @@ mod js {
     #[wasm_bindgen_test]
     fn global_new() {
         let mut store = Store::default();
-        let _env = FunctionEnv::new(&mut store, ());
         let global = Global::new(&mut store, Value::I32(10));
         assert_eq!(
             global.ty(&store),
@@ -29,7 +28,6 @@ mod js {
     #[wasm_bindgen_test]
     fn global_get() {
         let mut store = Store::default();
-        let _env = FunctionEnv::new(&mut store, ());
         let global_i32 = Global::new(&mut store, Value::I32(10));
         assert_eq!(global_i32.get(&store), Value::I32(10));
         // 64-bit values are not yet fully supported in some versions of Node
@@ -46,7 +44,6 @@ mod js {
     #[wasm_bindgen_test]
     fn global_set() {
         let mut store = Store::default();
-        let _env = FunctionEnv::new(&mut store, ());
         let global_i32 = Global::new(&mut store, Value::I32(10));
         // Set on a constant should error
         assert!(global_i32.set(&mut store, Value::I32(20)).is_err());
@@ -144,7 +141,6 @@ mod js {
     #[wasm_bindgen_test]
     fn memory_new() {
         let mut store = Store::default();
-        let _env = FunctionEnv::new(&mut store, ());
         let memory_type = MemoryType {
             shared: false,
             minimum: Pages(0),
@@ -158,7 +154,6 @@ mod js {
     #[wasm_bindgen_test]
     fn memory_grow() {
         let mut store = Store::default();
-        let _env = FunctionEnv::new(&mut store, ());
 
         let desc = MemoryType::new(Pages(10), Some(Pages(16)), false);
         let memory = Memory::new(&mut store, desc).unwrap();
@@ -444,7 +439,6 @@ mod js {
     #[wasm_bindgen_test]
     fn function_outlives_instance() {
         let mut store = Store::default();
-        let _env = FunctionEnv::new(&mut store, ());
         let wat = r#"(module
       (type $sum_t (func (param i32 i32) (result i32)))
       (func $sum_f (type $sum_t) (param $x i32) (param $y i32) (result i32)