advanced/WasmMem bindings

crates/api/examples/hello4.rs

@@ -7,13 +7,23 @@ use wasmtime_api::*;
 #[macro_use]
 extern crate wasmtime_bindings_macro;
 
-struct Callback;
+pub struct Syscalls;
 
-#[wasmtime_impl(module(callback_mod))]
-impl Callback {
-    fn callback(&self) {
-        println!("Calling back...");
-        println!("> Hello World!");
+use wasmtime_bindings_macro::wasmtime_impl;
+#[wasmtime_impl(module(syscalls_mod), context(wasmtime_wasi::WasiMem))]
+impl Syscalls {
+    fn __print_char(&self, c: u8) {
+        print!("{}", c as char);
+    }
+
+    fn __print_string(&self, buf: *mut u8, length: i32, capacity: i32) {
+        let s =
+            //unsafe { std::string::String::from_raw_parts(buf, length as usize, capacity as usize) };
+            String::from(
+                std::str::from_utf8(unsafe { std::slice::from_raw_parts(buf, length as usize) }).unwrap()
+            );
+
+        print!("{}", s);
     }
 }
 
@@ -30,7 +40,7 @@ fn main() -> Result<()> {
 
     // Load binary.
     println!("Loading binary...");
-    let binary = read("examples/hello.wasm")?;
+    let binary = read("examples/hello4.wasm")?;
 
     // Compile.
     println!("Compiling module...");
@@ -40,15 +50,15 @@ fn main() -> Result<()> {
 
     // Create external print functions.
     println!("Creating callback...");
-    let callback_mod = HostRef::new(
+    let syscalls_mod = HostRef::new(
         wrap_wasmtime_module!(
-            &store, |_imports| Callback; module(callback_mod)
+            &store, |_imports| Syscalls; module(syscalls_mod)
         )
         .map_err(|_| format_err!("> Error compiling callback module!"))?,
     );
-    let callback_instance = Instance::new(&store, &callback_mod, &[])
+    let callback_instance = Instance::new(&store, &syscalls_mod, &[])
         .map_err(|_| format_err!("> Error instantiating callback module!"))?;
-    let hello_func = &callback_instance.exports()[0];
+    let hello_func = &callback_instance.exports()[1];
 
     // Instantiate.
     println!("Instantiating module...");

crates/api/examples/hello4.wat

@@ -0,0 +1,8 @@
+(module
+  (import "" "__print_string" (func $print_string (param i32 i32 i32)))
+  (memory (export "memory") 1 1)
+  (func (export "run")
+    (call $print_string (i32.const 0) (i32.const 9) (i32.const 9))
+  )
+  (data (i32.const 0) "Hello, 4!")
+)

crates/api/src/trampoline/create_handle.rs

@@ -19,9 +19,10 @@ pub(crate) fn create_handle(
     signature_registry: Option<RefMut<Store>>,
     finished_functions: PrimaryMap<DefinedFuncIndex, *const VMFunctionBody>,
     state: Box<dyn Any>,
+    global_exports: Option<Rc<RefCell<HashMap<String, Option<wasmtime_runtime::Export>>>>>,
 ) -> Result<InstanceHandle> {
     let global_exports: Rc<RefCell<HashMap<String, Option<wasmtime_runtime::Export>>>> =
-        Rc::new(RefCell::new(HashMap::new()));
+        global_exports.unwrap_or_else(|| Rc::new(RefCell::new(HashMap::new())));
 
     let imports = Imports::new(
         HashSet::new(),

crates/api/src/trampoline/func.rs

@@ -239,6 +239,7 @@ pub fn create_handle_with_function(
         Some(store.borrow_mut()),
         finished_functions,
         Box::new(trampoline_state),
+        None,
     )
 }
 
@@ -264,6 +265,7 @@ pub fn create_handle_for_wrapped(
         Some(store.borrow_mut()),
         finished_functions,
         Box::new(()),
+        None,
     )
 }
 
@@ -296,7 +298,14 @@ pub fn create_handle_for_trait(
 
     let state = state_builder.build_state(externs);
 
-    create_handle(module, Some(store.borrow_mut()), finished_functions, state)
+    let exports = store.borrow().global_exports().clone();
+    create_handle(
+        module,
+        Some(store.borrow_mut()),
+        finished_functions,
+        state,
+        Some(exports),
+    )
 }
 
 /// We don't expect trampoline compilation to produce any relocations, so

crates/api/src/trampoline/global.rs

@@ -33,7 +33,7 @@ pub fn create_global(gt: &GlobalType, val: Val) -> Result<(wasmtime_runtime::Exp
         initializer: cranelift_wasm::GlobalInit::Import, // TODO is it right?
     };
     let mut handle =
-        create_handle(Module::new(), None, PrimaryMap::new(), Box::new(())).expect("handle");
+        create_handle(Module::new(), None, PrimaryMap::new(), Box::new(()), None).expect("handle");
     Ok((
         wasmtime_runtime::Export::Global {
             definition: definition.as_mut(),

crates/api/src/trampoline/memory.rs

@@ -30,5 +30,5 @@ pub fn create_handle_with_memory(memory: &MemoryType) -> Result<InstanceHandle>
         wasmtime_environ::Export::Memory(memory_id),
     );
 
-    create_handle(module, None, PrimaryMap::new(), Box::new(()))
+    create_handle(module, None, PrimaryMap::new(), Box::new(()), None)
 }

crates/api/src/trampoline/table.rs

@@ -32,5 +32,5 @@ pub fn create_handle_with_table(table: &TableType) -> Result<InstanceHandle> {
         wasmtime_environ::Export::Table(table_id),
     );
 
-    create_handle(module, None, PrimaryMap::new(), Box::new(()))
+    create_handle(module, None, PrimaryMap::new(), Box::new(()), None)
 }

crates/bindings/src/lib.rs

@@ -74,6 +74,12 @@ impl IntoIRType for i32 {
     }
 }
 
+impl IntoIRType for u32 {
+    fn into_ir_type() -> codegen::ir::Type {
+        codegen::ir::types::I32
+    }
+}
+
 impl IntoIRType for i64 {
     fn into_ir_type() -> codegen::ir::Type {
         codegen::ir::types::I64

crates/wasi/src/lib.rs

@@ -8,5 +8,5 @@ mod trait_impl;
 #[macro_use]
 extern crate wasmtime_bindings_macro;
 pub use instantiate::{instantiate_wasi, instantiate_wasi_with_context};
-pub use r#trait::{wasi_mod, Wasi};
+pub use r#trait::{wasi_mod, Wasi, WasiMem};
 pub use trait_impl::instantiate_wasi2;