fix: appending to nil not creating new array

duzhanyuan · Apr 25, 2022 · eac2646 · eac2646
1 parent fd8c09d
commit eac2646
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Showing 3 changed files with 40 additions and 6 deletions.
diff --git a/engine/tests/group1/slice1.gos b/engine/tests/group1/slice1.gos
@@ -87,6 +87,16 @@ func copy_slice() {
 }
 
 
+func appendToNil() {
+    var a []int
+    b := []int{6,6,6}
+    a = append(a, b...)
+    a[0] = 123
+    assert(a[0] == 123)
+    assert(b[0] == 6)
+}
+
+
 
 func main() {
     var s1 = [][]int{{0},{99},{2}}
@@ -105,4 +115,6 @@ func main() {
     append_slice()
 
     copy_slice()
+
+    appendToNil()
 }
diff --git a/vm/src/value.rs b/vm/src/value.rs
@@ -2646,7 +2646,12 @@ pub trait Dispatcher {
 
     fn slice_array(&self, arr: GosValue, begin: isize, end: isize) -> RuntimeResult<GosValue>;
 
-    fn slice_append(&self, this: GosValue, other: GosValue) -> GosValue;
+    fn slice_append(
+        &self,
+        this: GosValue,
+        other: GosValue,
+        gcv: &GcoVec,
+    ) -> RuntimeResult<GosValue>;
 
     fn slice_copy_from(&self, this: GosValue, other: GosValue) -> usize;
 
@@ -2793,19 +2798,33 @@ macro_rules! define_dispatcher {
             }
 
             #[inline]
-            fn slice_append(&self, this: GosValue, other: GosValue) -> GosValue {
+            fn slice_append(
+                &self,
+                this: GosValue,
+                other: GosValue,
+                gcv: &GcoVec,
+            ) -> RuntimeResult<GosValue> {
                 let a = this.as_slice::<$elem>();
                 let b = other.as_slice::<$elem>();
                 match b {
                     Some(y) => match a {
                         Some(x) => {
                             let mut to = x.0.clone();
                             to.append(&y.0);
-                            GosValue::new_slice(to, other.t_elem())
+                            Ok(GosValue::new_slice(to, other.t_elem()))
+                        }
+                        None => {
+                            let data = y.0.as_rust_slice().to_vec();
+                            let arr = ArrayObj::<$elem>::with_raw_data(data);
+                            let slice = SliceObj::<$elem>::with_array(
+                                GosValue::new_array(arr, other.t_elem(), gcv),
+                                0,
+                                -1,
+                            )?;
+                            Ok(GosValue::new_slice(slice, other.t_elem()))
                         }
-                        None => GosValue::new_slice(SliceObj::clone(&y.0), other.t_elem()),
                     },
-                    None => this,
+                    None => Ok(this),
                 }
             }
 

diff --git a/vm/src/vm.rs b/vm/src/vm.rs
@@ -1351,7 +1351,10 @@ impl<'a> Fiber<'a> {
                         };
                         let b = stack.pop_value();
                         let a = stack.pop_value();
-                        stack.push(dispatcher_a_s_for(inst.t0()).slice_append(a, b));
+                        match dispatcher_a_s_for(inst.t0()).slice_append(a, b, gcv) {
+                            Ok(slice) => stack.push(slice),
+                            Err(e) => go_panic_str!(panic, &e, frame, code),
+                        };
                     }
                     Opcode::COPY => {
                         let t2 = match inst.t2() {