quick fix to remove the leak from symmetric calls

crates/rust/src/bindgen.rs

@@ -825,6 +825,11 @@ impl Bindgen for FunctionBindgen<'_, '_> {
                 self.push_str(&format!(
                     "let ptr = {alloc}::alloc({layout}).cast::<u8>();\n",
                 ));
+                if self.gen.gen.opts.symmetric && self.gen.in_import {
+                    self.push_str(&format!(
+                        "if !ptr.is_null() {{ _deallocate.push((ptr, {layout})); }}\n"
+                    ));
+                }
                 self.push_str(&format!(
                     "if ptr.is_null()\n{{\n{alloc}::handle_alloc_error({layout});\n}}\nptr\n}}",
                 ));
@@ -909,6 +914,9 @@ impl Bindgen for FunctionBindgen<'_, '_> {
                 self.push_str("(");
                 self.push_str(&operands.join(", "));
                 self.push_str(");\n");
+                if self.gen.gen.opts.symmetric && self.gen.in_import {
+                    self.push_str(&format!("for (ptr,layout) in _deallocate.drain(..) {{ _rt::alloc::dealloc(ptr, layout); }}\n"));
+                }
             }
 
             Instruction::AsyncCallWasm { name, size, align } => {

crates/rust/src/interface.rs

@@ -867,6 +867,12 @@ impl {async_support}::StreamPayload for {name} {{
         self.src.push_str("#[allow(unused_unsafe, clippy::all)]\n");
         let params = self.print_signature(func, false, &sig, true);
         self.src.push_str("{\n");
+        if self.gen.opts.symmetric {
+            uwriteln!(
+                self.src,
+                "let mut _deallocate: Vec<(*mut u8, _rt::alloc::Layout)> = Vec::new();"
+            );
+        }
         self.src.push_str("unsafe {\n");
 
         self.generate_guest_import_body(&self.wasm_import_module, func, params, async_);