Add basic pyobject c-api functions (#7872)

crates/capi/src/object.rs

@@ -1,7 +1,8 @@
 use crate::PyObject;
 use crate::pystate::with_vm;
-use core::ffi::{c_int, c_uint, c_ulong};
-use rustpython_vm::builtins::PyType;
+use core::ffi::{CStr, c_char, c_int, c_uint, c_ulong};
+use core::ptr::NonNull;
+use rustpython_vm::builtins::{PyStr, PyType};
 use rustpython_vm::{AsObject, Py};
 
 pub type PyTypeObject = Py<PyType>;
@@ -46,3 +47,91 @@ pub extern "C" fn Py_GetConstantBorrowed(constant_id: c_uint) -> *mut PyObject {
         Ok(constant)
     })
 }
+
+#[unsafe(no_mangle)]
+pub unsafe extern "C" fn PyObject_GetAttr(
+    obj: *mut PyObject,
+    name: *mut PyObject,
+) -> *mut PyObject {
+    with_vm(|vm| {
+        let obj = unsafe { &*obj };
+        let name = unsafe { &*name }.try_downcast_ref::<PyStr>(vm)?;
+        obj.get_attr(name, vm)
+    })
+}
+
+#[unsafe(no_mangle)]
+pub unsafe extern "C" fn PyObject_GetAttrString(
+    obj: *mut PyObject,
+    attr_name: *const c_char,
+) -> *mut PyObject {
+    with_vm(|vm| {
+        let obj = unsafe { &*obj };
+        let name = unsafe {
+            CStr::from_ptr(attr_name)
+                .to_str()
+                .expect("attribute name must be valid UTF-8")
+        };
+        obj.get_attr(name, vm)
+    })
+}
+
+#[unsafe(no_mangle)]
+pub unsafe extern "C" fn PyObject_SetAttrString(
+    obj: *mut PyObject,
+    attr_name: *const c_char,
+    value: *mut PyObject,
+) -> c_int {
+    with_vm(|vm| {
+        let obj = unsafe { &*obj };
+        let name = unsafe { CStr::from_ptr(attr_name) }
+            .to_str()
+            .expect("attribute name must be valid UTF-8");
+        let value = unsafe { &*value }.to_owned();
+        obj.set_attr(name, value, vm)
+    })
+}
+
+#[unsafe(no_mangle)]
+pub unsafe extern "C" fn PyObject_SetAttr(
+    obj: *mut PyObject,
+    name: *mut PyObject,
+    value: *mut PyObject,
+) -> c_int {
+    with_vm(|vm| {
+        let obj = unsafe { &*obj };
+        let name = unsafe { &*name }.try_downcast_ref::<PyStr>(vm)?;
+        let value = unsafe { &*value }.to_owned();
+        obj.set_attr(name, value, vm)
+    })
+}
+
+#[unsafe(no_mangle)]
+pub extern "C" fn PyObject_Repr(obj: *mut PyObject) -> *mut PyObject {
+    with_vm(|vm| {
+        let Some(obj) = NonNull::new(obj) else {
+            return Ok(vm.ctx.new_str("<NULL>"));
+        };
+
+        unsafe { obj.as_ref() }.repr(vm)
+    })
+}
+
+#[unsafe(no_mangle)]
+pub extern "C" fn PyObject_Str(obj: *mut PyObject) -> *mut PyObject {
+    with_vm(|vm| {
+        let Some(obj) = NonNull::new(obj) else {
+            return Ok(vm.ctx.new_str("<NULL>"));
+        };
+
+        unsafe { obj.as_ref() }.str(vm)
+    })
+}
+
+#[unsafe(no_mangle)]
+pub unsafe extern "C" fn PyObject_IsTrue(obj: *mut PyObject) -> c_int {
+    with_vm(|vm| {
+        let obj = unsafe { &*obj };
+        obj.to_owned().is_true(vm)
+    })
+}