From 0b1a1f5181fdc3541397bef00a42245fb3817a3c Mon Sep 17 00:00:00 2001
From: xinchengxx <2240131203@qq.com>
Date: Tue, 11 Mar 2025 19:12:28 +0800
Subject: [PATCH] Fix code generation to comply with rfc 2585

---
 engine/src/conversion/analysis/fun/mod.rs     |  7 -------
 .../src/conversion/codegen_rs/fun_codegen.rs  | 21 +++++++++++--------
 engine/src/lib.rs                             |  4 ++--
 3 files changed, 14 insertions(+), 18 deletions(-)

diff --git a/engine/src/conversion/analysis/fun/mod.rs b/engine/src/conversion/analysis/fun/mod.rs
index 6ad07ef2c..07c7eb75f 100644
--- a/engine/src/conversion/analysis/fun/mod.rs
+++ b/engine/src/conversion/analysis/fun/mod.rs
@@ -108,9 +108,6 @@ pub(crate) struct TraitMethodDetails {
     /// interface, we may need to reorder the parameters to fit that
     /// interface.
     pub(crate) parameter_reordering: Option<Vec<usize>>,
-    /// The function we're calling from the trait requires unsafe even
-    /// though the trait and its function aren't.
-    pub(crate) trait_call_is_unsafe: bool,
 }
 
 #[derive(Clone, Debug)]
@@ -894,7 +891,6 @@ impl<'a> FnAnalyzer<'a> {
                                 avoid_self: true,
                                 method_name: make_ident(method_name),
                                 parameter_reordering: Some(vec![1, 0]),
-                                trait_call_is_unsafe: false,
                             }),
                         },
                         error_context,
@@ -930,7 +926,6 @@ impl<'a> FnAnalyzer<'a> {
                             avoid_self: false,
                             method_name: make_ident("drop"),
                             parameter_reordering: None,
-                            trait_call_is_unsafe: false,
                         }),
                     },
                     error_context,
@@ -1582,7 +1577,6 @@ impl<'a> FnAnalyzer<'a> {
                             avoid_self: false,
                             method_name,
                             parameter_reordering: None,
-                            trait_call_is_unsafe: false,
                         }),
                     },
                     ErrorContext::new_for_item(make_ident(&rust_name)),
@@ -1626,7 +1620,6 @@ impl<'a> FnAnalyzer<'a> {
                     avoid_self: false,
                     method_name: make_ident(method_name),
                     parameter_reordering: None,
-                    trait_call_is_unsafe: false,
                 }),
                 kind,
             },
diff --git a/engine/src/conversion/codegen_rs/fun_codegen.rs b/engine/src/conversion/codegen_rs/fun_codegen.rs
index 9e00da576..4317fb56e 100644
--- a/engine/src/conversion/codegen_rs/fun_codegen.rs
+++ b/engine/src/conversion/codegen_rs/fun_codegen.rs
@@ -109,16 +109,12 @@ pub(super) fn gen_function(
     let mut cpp_name_attr = Vec::new();
     let mut impl_entry = None;
     let mut trait_impl_entry = None;
-    let always_unsafe_due_to_trait_definition = match kind {
-        FnKind::TraitMethod { ref details, .. } => details.trait_call_is_unsafe,
-        _ => false,
-    };
+
     let fn_generator = FnGenerator {
         param_details: &param_details,
         cxxbridge_name: &cxxbridge_name,
         rust_name,
         unsafety: &analysis.requires_unsafe,
-        always_unsafe_due_to_trait_definition,
         doc_attrs: &doc_attrs,
         non_pod_types,
         ret_type: &ret_type,
@@ -229,7 +225,6 @@ struct FnGenerator<'a> {
     cxxbridge_name: &'a Ident,
     rust_name: &'a str,
     unsafety: &'a UnsafetyNeeded,
-    always_unsafe_due_to_trait_definition: bool,
     doc_attrs: &'a Vec<Attribute>,
     non_pod_types: &'a HashSet<QualifiedName>,
 }
@@ -309,10 +304,18 @@ impl<'a> FnGenerator<'a> {
             quote! {
                 cxxbridge::#cxxbridge_name ( #(#arg_list),* )
             },
-            any_conversion_requires_unsafe || matches!(self.unsafety, UnsafetyNeeded::JustBridge),
+            any_conversion_requires_unsafe
+                || matches!(
+                    self.unsafety,
+                    UnsafetyNeeded::JustBridge | UnsafetyNeeded::Always
+                ),
         );
-        let context_is_unsafe = matches!(self.unsafety, UnsafetyNeeded::Always)
-            || self.always_unsafe_due_to_trait_definition;
+
+        // Per RFC 2585 (https://rust-lang.github.io/rfcs/2585-unsafe-block-in-unsafe-fn.html),
+        // all calls to unsafe functions must be wrapped in an unsafe block, even within an unsafe function.
+        // Therefore, the outer context is always treated as "safe" (false), ensuring proper unsafe blocks
+        // are generated around unsafe operations.
+        let context_is_unsafe = false;
         let (call_body, ret_type) = match self.ret_conversion {
             Some(ret_conversion) if ret_conversion.rust_work_needed() => {
                 // There's a potential lurking bug below. If the return type conversion requires
diff --git a/engine/src/lib.rs b/engine/src/lib.rs
index 26a126de8..18857e1e1 100644
--- a/engine/src/lib.rs
+++ b/engine/src/lib.rs
@@ -367,7 +367,8 @@ impl IncludeCppEngine {
             .raw_line(raw_line)
             .every_module_raw_line(all_module_raw_line)
             .generate_private_functions(true)
-            .layout_tests(false); // TODO revisit later
+            .layout_tests(false) // TODO revisit later
+            .wrap_unsafe_ops(true);
 
         // 3. Passes allowlist and other options to the bindgen::Builder equivalent
         //    to --output-style=cxx --allowlist=<as passed in>
@@ -519,7 +520,6 @@ impl IncludeCppEngine {
             #[allow(dead_code)]
             #[allow(non_upper_case_globals)]
             #[allow(non_camel_case_types)]
-            #[allow(unsafe_op_in_unsafe_fn)]
             #[doc = "Generated using autocxx - do not edit directly"]
             #[doc = "@generated"]
             mod #mod_name {