PackedFunc returns result

Author: nhynes

rust/common/src/lib.rs

@@ -19,6 +19,13 @@ pub mod ffi {
 
     pub type BackendPackedCFunc =
         extern "C" fn(args: *const TVMValue, type_codes: *const c_int, num_args: c_int) -> c_int;
+
+    pub fn get_last_error() -> String {
+        unsafe { std::ffi::CStr::from_ptr(TVMGetLastError()) }
+            .to_str()
+            .expect("double fault")
+            .to_owned()
+    }
 }
 
 pub mod array;

rust/common/src/packed_func.rs

@@ -3,7 +3,7 @@ use std::{any::Any, convert::TryFrom, marker::PhantomData, os::raw::c_void, str:
 pub use crate::ffi::TVMValue;
 use crate::{errors::*, ffi::*, value::*};
 
-pub type PackedFunc = Box<Fn(&[TVMArgValue]) -> TVMRetValue + Send + Sync>;
+pub type PackedFunc = Box<Fn(&[TVMArgValue]) -> Result<TVMRetValue>>;
 
 /// Calls a packed function and returns a `TVMRetValue`.
 ///

rust/runtime/src/graph.rs

@@ -279,7 +279,7 @@ impl<'m, 't> GraphExecutor<'m, 't> {
                     .iter()
                     .map(|t| t.into())
                     .collect::<Vec<TVMArgValue>>();
-                func(args.as_slice());
+                func(args.as_slice()).unwrap();
             };
             op_execs.push(op);
         }

rust/runtime/src/module.rs

@@ -36,7 +36,7 @@ impl Default for SystemLibModule {
 // @see `WrapPackedFunc` in `llvm_module.cc`.
 pub(super) fn wrap_backend_packed_func(func: BackendPackedCFunc) -> PackedFunc {
     box move |args: &[TVMArgValue]| {
-        func(
+        let exit_code = func(
             args.iter()
                 .map(|ref arg| arg.value)
                 .collect::<Vec<TVMValue>>()
@@ -47,7 +47,11 @@ pub(super) fn wrap_backend_packed_func(func: BackendPackedCFunc) -> PackedFunc {
                 .as_ptr() as *const i32,
             args.len() as i32,
         );
-        TVMRetValue::default()
+        if exit_code == 0 {
+            Ok(TVMRetValue::default())
+        } else {
+            Err(tvm_common::ffi::get_last_error().into())
+        }
     }
 }