Initial reorg.

This is largely the same as #305, but updated for the current tree.

crates/misc/py/src/value.rs

@@ -0,0 +1,61 @@
+//! Utility functions to handle values conversion between abstractions/targets.
+
+use pyo3::exceptions::Exception;
+use pyo3::prelude::*;
+use pyo3::types::PyAny;
+
+use core::ptr;
+use cranelift_codegen::ir;
+use wasmtime_interface_types::Value;
+
+pub fn pyobj_to_value(_: Python, p: &PyAny) -> PyResult<Value> {
+    if let Ok(n) = p.extract() {
+        Ok(Value::I32(n))
+    } else if let Ok(n) = p.extract() {
+        Ok(Value::U32(n))
+    } else if let Ok(n) = p.extract() {
+        Ok(Value::I64(n))
+    } else if let Ok(n) = p.extract() {
+        Ok(Value::U64(n))
+    } else if let Ok(n) = p.extract() {
+        Ok(Value::F64(n))
+    } else if let Ok(n) = p.extract() {
+        Ok(Value::F32(n))
+    } else if let Ok(s) = p.extract() {
+        Ok(Value::String(s))
+    } else {
+        Err(PyErr::new::<Exception, _>("unsupported value type"))
+    }
+}
+
+pub fn value_to_pyobj(py: Python, value: Value) -> PyResult<PyObject> {
+    Ok(match value {
+        Value::I32(i) => i.into_py(py),
+        Value::U32(i) => i.into_py(py),
+        Value::I64(i) => i.into_py(py),
+        Value::U64(i) => i.into_py(py),
+        Value::F32(i) => i.into_py(py),
+        Value::F64(i) => i.into_py(py),
+        Value::String(i) => i.into_py(py),
+    })
+}
+
+pub unsafe fn read_value_from(py: Python, ptr: *mut i64, ty: ir::Type) -> PyObject {
+    match ty {
+        ir::types::I32 => ptr::read(ptr as *const i32).into_py(py),
+        ir::types::I64 => ptr::read(ptr as *const i64).into_py(py),
+        ir::types::F32 => ptr::read(ptr as *const f32).into_py(py),
+        ir::types::F64 => ptr::read(ptr as *const f64).into_py(py),
+        _ => panic!("TODO add PyResult to read_value_from"),
+    }
+}
+
+pub unsafe fn write_value_to(py: Python, ptr: *mut i64, ty: ir::Type, val: PyObject) {
+    match ty {
+        ir::types::I32 => ptr::write(ptr as *mut i32, val.extract::<i32>(py).expect("i32")),
+        ir::types::I64 => ptr::write(ptr as *mut i64, val.extract::<i64>(py).expect("i64")),
+        ir::types::F32 => ptr::write(ptr as *mut f32, val.extract::<f32>(py).expect("f32")),
+        ir::types::F64 => ptr::write(ptr as *mut f64, val.extract::<f64>(py).expect("f64")),
+        _ => panic!("TODO add PyResult to write_value_to"),
+    }
+}