Pass temp value as ref into ctx.

sharksforarms · Jul 25, 2023 · 55b44fb · 55b44fb
1 parent d045596
commit 55b44fb
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Showing 3 changed files with 35 additions and 5 deletions.
diff --git a/deku-derive/src/macros/deku_write.rs b/deku-derive/src/macros/deku_write.rs
@@ -534,8 +534,8 @@ fn emit_field_write(
             if let Some(temp_value) = &f.temp_value {
                 let field_type = &f.ty;
                 quote! {
-                    let #field_ident: #field_type = #temp_value;
-                    ::#crate_::DekuWrite::write(#object_prefix &#field_ident, __deku_output, (#write_args))
+                    let #field_ident: &#field_type = &#temp_value;
+                    ::#crate_::DekuWrite::write(#object_prefix #field_ident, __deku_output, (#write_args))
                 }
             } else {
                 quote! { core::result::Result::<(), ::#crate_::DekuError>::Ok(()) }

diff --git a/src/attributes.rs b/src/attributes.rs
@@ -511,7 +511,7 @@ Example:
 #[deku_derive(DekuRead, DekuWrite)]
 #[derive(Debug, PartialEq)]
 struct DekuTest {
-    #[deku(temp, temp_value = "items.len() as u8")]
+    #[deku(temp, temp_value = "(items.len() as u8)")]
     num_items: u8,
 
     #[deku(count = "num_items", endian = "big")]

diff --git a/tests/test_attributes/test_temp.rs b/tests/test_attributes/test_temp.rs
@@ -6,7 +6,7 @@ fn test_temp_field_write() {
     #[deku_derive(DekuRead, DekuWrite)]
     #[derive(PartialEq, Debug)]
     struct TestStruct {
-        #[deku(temp, temp_value = "self.field_b.len() as _")]
+        #[deku(temp, temp_value = "(self.field_b.len() as _)")]
         field_a: u8,
         #[deku(count = "field_a")]
         field_b: Vec<u8>,
@@ -88,7 +88,7 @@ fn test_temp_field_unnamed_write() {
     #[deku_derive(DekuRead, DekuWrite)]
     #[derive(PartialEq, Debug)]
     struct TestStruct(
-        #[deku(temp, temp_value = "self.0.len() as _")] u8,
+        #[deku(temp, temp_value = "(self.0.len() as _)")] u8,
         #[deku(count = "field_0")] Vec<u8>,
     );
 
@@ -160,3 +160,33 @@ fn test_temp_enum_field_write() {
     let ret_write: Vec<u8> = TestEnum::VarB(0x10).to_bytes().unwrap();
     assert_eq!(test_data, ret_write);
 }
+
+#[test]
+fn test_context() {
+    use deku::prelude::*;
+    use std::convert::TryInto;
+
+    #[deku_derive(DekuRead, DekuWrite)]
+    #[derive(Debug, PartialEq)]
+    #[deku(ctx = "_field1: u8, _field2: u8")]
+    struct Child {}
+
+    #[deku_derive(DekuRead, DekuWrite)]
+    #[derive(Debug, PartialEq)]
+    struct Parent {
+        pub field1: u8,
+
+        #[deku(temp, temp_value = "self.field1")]
+        pub field2: u8,
+
+        #[deku(ctx = "*field1, *field2")]
+        pub field3: Child,
+    }
+
+    let value = Parent {
+        field1: 0x01,
+        field3: Child {},
+    };
+    let value: Vec<u8> = value.try_into().unwrap();
+    assert_eq!(vec![0x01, 0x01], value);
+}