Make rustc stop complaining about unused `Box::from_raw`s

[ldk-c-bindings] / c-bindings-gen / src / blocks.rs

diff --git a/c-bindings-gen/src/blocks.rs b/c-bindings-gen/src/blocks.rs
index e97fb65e88e4c0a58dfcf82e959e48515aecbc9f..28f30026ed0810ef0263be3a8b4636a234d59b54 100644 (file)
--- a/c-bindings-gen/src/blocks.rs
+++ b/c-bindings-gen/src/blocks.rs
@@ -250,7 +250,7 @@ pub fn write_vec_block<W: std::io::Write>(w: &mut W, mangled_container: &str, in
        writeln!(w, "impl Drop for {} {{", mangled_container).unwrap();
        writeln!(w, "\tfn drop(&mut self) {{").unwrap();
        writeln!(w, "\t\tif self.datalen == 0 {{ return; }}").unwrap();
-       writeln!(w, "\t\tunsafe {{ Box::from_raw(core::slice::from_raw_parts_mut(self.data, self.datalen)) }};").unwrap();
+       writeln!(w, "\t\tlet _ = unsafe {{ Box::from_raw(core::slice::from_raw_parts_mut(self.data, self.datalen)) }};").unwrap();
        writeln!(w, "\t}}").unwrap();
        writeln!(w, "}}").unwrap();
        if clonable {
@@ -460,7 +460,7 @@ fn writeln_docs_impl<'a, W: std::io::Write, I>(w: &mut W, attrs: &[syn::Attribut
                        },
                }
        }
-       if let Some((types, generics, inp, outp, field)) = method_args_ret {
+       if let Some((types, generics, inp, outp, field_ty)) = method_args_ret {
                let mut nullable_found = false;
                for (name, inp) in inp {
                        if types.skip_arg(inp, generics) { continue; }
@@ -491,8 +491,13 @@ fn writeln_docs_impl<'a, W: std::io::Write, I>(w: &mut W, attrs: &[syn::Attribut
                        nullable_found = true;
                        writeln!(w, "{}/// Note that the return value (or a relevant inner pointer) may be NULL or all-0s to represent None", prefix).unwrap();
                }
+               let field = field_ty.map(|ty| generics.resolve_type(ty));
                if if let Some(syn::Type::Reference(syn::TypeReference { elem, .. })) = field {
                        if let syn::Type::Path(syn::TypePath { ref path, .. }) = &**elem {
+                               let resolved_path = types.resolve_path(path, generics);
+                               if types.crate_types.opaques.get(&resolved_path).is_some() {
+                                       writeln!(w, "{}/// Note that this field is expected to be a reference.", prefix).unwrap();
+                               }
                                types.is_path_transparent_container(path, generics, true)
                        } else { false }
                } else if let Some(syn::Type::Path(syn::TypePath { ref path, .. })) = field {
@@ -571,7 +576,7 @@ pub fn write_method_params<W: std::io::Write>(w: &mut W, sig: &syn::Signature, t
                                        },
                                        _ => unimplemented!(),
                                }
-                               w.write(&c_type).unwrap();
+                               w.write_all(&c_type).unwrap();
                        }
                }
        }
@@ -742,7 +747,7 @@ pub fn write_method_call_params<W: std::io::Write>(w: &mut W, sig: &syn::Signatu
 
 /// Prints concrete generic parameters for a struct/trait/function, including the less-than and
 /// greater-than symbols, if any generic parameters are defined.
-pub fn maybe_write_generics<W: std::io::Write>(w: &mut W, generics: &syn::Generics, types: &TypeResolver, concrete_lifetimes: bool) {
+pub fn maybe_write_generics<W: std::io::Write>(w: &mut W, generics: &syn::Generics, generics_impld: &syn::PathArguments, types: &TypeResolver, concrete_lifetimes: bool) {
        let mut gen_types = GenericTypes::new(None);
        assert!(gen_types.learn_generics(generics, types));
        if generics.params.is_empty() { return; }
@@ -773,7 +778,15 @@ pub fn maybe_write_generics<W: std::io::Write>(w: &mut W, generics: &syn::Generi
                        syn::GenericParam::Type(type_param) => {
                                write!(w, "{}", if idx != 0 { ", " } else { "" }).unwrap();
                                let type_ident = &type_param.ident;
-                               types.write_c_type_in_generic_param(w, &syn::parse_quote!(#type_ident), Some(&gen_types), false);
+                               if types.understood_c_type(&syn::parse_quote!(#type_ident), Some(&gen_types)) {
+                                       types.write_c_type_in_generic_param(w, &syn::parse_quote!(#type_ident), Some(&gen_types), false);
+                               } else {
+                                       if let syn::PathArguments::AngleBracketed(args) = generics_impld {
+                                               if let syn::GenericArgument::Type(ty) = &args.args[idx] {
+                                                       types.write_c_type_in_generic_param(w, &ty, Some(&gen_types), false);
+                                               }
+                                       }
+                               }
                        },
                        syn::GenericParam::Lifetime(lt) => {
                                if concrete_lifetimes {