feat: add doom example, fix import argument order

Signed-off-by: Henry <mail@henrygressmann.de>

3 files changed, 47 insertions, 1 deletions

diff --git a/crates/tinywasm/src/interpreter/executor.rs b/crates/tinywasm/src/interpreter/executor.rs
index b1178d8..4d862d6 100644
--- a/crates/tinywasm/src/interpreter/executor.rs
+++ b/crates/tinywasm/src/interpreter/executor.rs
@@ -6,6 +6,7 @@ use super::no_std_floats::NoStdFloatExt;
 
 use alloc::boxed::Box;
 use alloc::rc::Rc;
+use alloc::vec::Vec;
 
 use alloc::sync::Arc;
 use interpreter::stack::CallFrame;
@@ -969,7 +970,8 @@ impl<'store, const BUDGETED: bool> Executor<'store, BUDGETED> {
     }
 
     fn exec_call_host(&mut self, host_func: Rc<HostFunction>) -> Result<(), Trap> {
-        let params = self.store.value_stack.pop_types(host_func.ty.params()).collect::<Box<_>>();
+        let mut params = self.store.value_stack.pop_types(host_func.ty.params().iter().rev()).collect::<Vec<_>>();
+        params.reverse();
         let res = match host_func.call(FuncContext { store: self.store, module_addr: self.module.idx() }, &params) {
             Ok(res) => res,
             Err(err) => {
diff --git a/crates/tinywasm/src/reference.rs b/crates/tinywasm/src/reference.rs
index 44916b4..5f8d46f 100644
--- a/crates/tinywasm/src/reference.rs
+++ b/crates/tinywasm/src/reference.rs
@@ -261,6 +261,19 @@ impl Memory {
         })
     }
 
+    /// Copies a nul-terminated C string into memory.
+    pub fn write_cstring(&self, store: &mut Store, offset: usize, string: &CString) -> Result<()> {
+        self.copy_from_slice(store, offset, string.as_bytes_with_nul())
+    }
+
+    /// Copies a UTF-8 string into memory and appends a trailing nul byte.
+    pub fn write_cstring_bytes(&self, store: &mut Store, offset: usize, string: &str) -> Result<()> {
+        let mut bytes = Vec::with_capacity(string.len() + 1);
+        bytes.extend_from_slice(string.as_bytes());
+        bytes.push(0);
+        self.copy_from_slice(store, offset, &bytes)
+    }
+
     /// Reads a C-style string from memory.
     pub fn read_cstring(&self, store: &Store, offset: usize, len: usize) -> Result<CString> {
         CString::from_vec_with_nul(self.read_vec(store, offset, len)?)
diff --git a/crates/tinywasm/tests/host_import_arg_order.rs b/crates/tinywasm/tests/host_import_arg_order.rs
new file mode 100644
index 0000000..2004641
--- /dev/null
+++ b/crates/tinywasm/tests/host_import_arg_order.rs
@@ -0,0 +1,31 @@
+use tinywasm::{HostFunction, Imports, ModuleInstance, Store};
+
+#[test]
+fn multi_arg_host_imports_preserve_source_order() {
+    let wasm = wat::parse_str(
+        r#"
+        (module
+          (import "env" "pair" (func $pair (param i32 i32) (result i32)))
+          (func (export "call_pair") (param i32 i32) (result i32)
+            local.get 0
+            local.get 1
+            call $pair))
+        "#,
+    )
+    .unwrap();
+
+    let module = tinywasm::parse_bytes(&wasm).unwrap();
+    let mut store = Store::default();
+
+    let pair = HostFunction::from(&mut store, |_ctx, (left, right): (i32, i32)| -> tinywasm::Result<i32> {
+        Ok(left * 1000 + right)
+    });
+
+    let mut imports = Imports::new();
+    imports.define("env", "pair", pair);
+
+    let instance = ModuleInstance::instantiate(&mut store, &module, Some(imports)).unwrap();
+    let func = instance.func::<(i32, i32), i32>(&store, "call_pair").unwrap();
+
+    assert_eq!(func.call(&mut store, (12, 34)).unwrap(), 12034);
+}