Missed a file in the last commit. Sorry! (0.38.0)

src/rust/src/vm/mod.rs

@@ -0,0 +1,70 @@
+/*
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2025 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ * Added: 2026-01-27
+ */
+
+//! Rust VM helpers and opcode handlers exposed via C ABI.
+//!
+//! Functions in this module are compiled into the Rust static library and can
+//! be called from the C VM. They operate on the VM stack using the minimal C
+//! ABI helpers declared on the C side (`vm_pop_i64`, `vm_push_i64`).
+
+use super::Vm;
+
+extern "C" {
+    fn vm_pop_i64(vm: *mut Vm) -> i64;
+    fn vm_push_i64(vm: *mut Vm, v: i64);
+}
+
+/// Multiply the top two integers on the VM stack.
+///
+/// Before: [..., a, b]
+/// After:  [..., a*b]
+#[no_mangle]
+pub extern "C" fn fun_op_rmul(vm: *mut Vm) -> i32 {
+    unsafe {
+        let b = vm_pop_i64(vm);
+        let a = vm_pop_i64(vm);
+        vm_push_i64(vm, a.saturating_mul(b));
+    }
+    0
+}
+
+/// Subtract the top two integers on the VM stack.
+///
+/// Before: [..., a, b]
+/// After:  [..., a-b]
+#[no_mangle]
+pub extern "C" fn fun_op_rsub(vm: *mut Vm) -> i32 {
+    unsafe {
+        let b = vm_pop_i64(vm);
+        let a = vm_pop_i64(vm);
+        vm_push_i64(vm, a.wrapping_sub(b));
+    }
+    0
+}
+
+/// Integer division of the top two integers on the VM stack (a / b).
+/// Pushes 0 and returns 1 when dividing by zero.
+///
+/// Before: [..., a, b]
+/// After:  [..., a/b]
+#[no_mangle]
+pub extern "C" fn fun_op_rdiv(vm: *mut Vm) -> i32 {
+    unsafe {
+        let b = vm_pop_i64(vm);
+        let a = vm_pop_i64(vm);
+        if b == 0 {
+            vm_push_i64(vm, 0);
+            return 1; // indicate error (div by zero)
+        }
+        vm_push_i64(vm, a / b);
+    }
+    0
+}