Merge pull request #11 from TheBlueMatt/2021-04-upstream-bump
[ldk-c-bindings] / c-bindings-gen / src / main.rs
index 1d37bb2b6335c4a538511b13345d5f01be36a5bc..f0c5db39982a7101cf82a459c07dbf8053d1f751 100644 (file)
 //! It also generates relevant memory-management functions and free-standing functions with
 //! parameters mapped.
 
-use std::collections::{HashMap, hash_map, HashSet};
+use std::collections::{HashMap, hash_map};
 use std::env;
 use std::fs::File;
 use std::io::{Read, Write};
 use std::process;
 
-use proc_macro2::{TokenTree, TokenStream, Span};
+use proc_macro2::Span;
 
 mod types;
 mod blocks;
@@ -35,38 +35,6 @@ use blocks::*;
 // *** Manually-expanded conversions ***
 // *************************************
 
-/// Because we don't expand macros, any code that we need to generated based on their contents has
-/// to be completely manual. In this case its all just serialization, so its not too hard.
-fn convert_macro<W: std::io::Write>(w: &mut W, macro_path: &syn::Path, stream: &TokenStream, types: &TypeResolver) {
-       assert_eq!(macro_path.segments.len(), 1);
-       match &format!("{}", macro_path.segments.iter().next().unwrap().ident) as &str {
-               "impl_writeable" | "impl_writeable_len_match" => {
-                       let struct_for = if let TokenTree::Ident(i) = stream.clone().into_iter().next().unwrap() { i } else { unimplemented!(); };
-                       if let Some(s) = types.maybe_resolve_ident(&struct_for) {
-                               if !types.crate_types.opaques.get(&s).is_some() { return; }
-                               writeln!(w, "#[no_mangle]").unwrap();
-                               writeln!(w, "/// Serialize the {} into a byte array which can be read by {}_read", struct_for, struct_for).unwrap();
-                               writeln!(w, "pub extern \"C\" fn {}_write(obj: &{}) -> crate::c_types::derived::CVec_u8Z {{", struct_for, struct_for).unwrap();
-                               writeln!(w, "\tcrate::c_types::serialize_obj(unsafe {{ &(*(*obj).inner) }})").unwrap();
-                               writeln!(w, "}}").unwrap();
-                               writeln!(w, "#[no_mangle]").unwrap();
-                               writeln!(w, "pub(crate) extern \"C\" fn {}_write_void(obj: *const c_void) -> crate::c_types::derived::CVec_u8Z {{", struct_for).unwrap();
-                               writeln!(w, "\tcrate::c_types::serialize_obj(unsafe {{ &*(obj as *const native{}) }})", struct_for).unwrap();
-                               writeln!(w, "}}").unwrap();
-                               writeln!(w, "#[no_mangle]").unwrap();
-                               writeln!(w, "/// Read a {} from a byte array, created by {}_write", struct_for, struct_for).unwrap();
-                               writeln!(w, "pub extern \"C\" fn {}_read(ser: crate::c_types::u8slice) -> {} {{", struct_for, struct_for).unwrap();
-                               writeln!(w, "\tif let Ok(res) = crate::c_types::deserialize_obj(ser) {{").unwrap();
-                               writeln!(w, "\t\t{} {{ inner: Box::into_raw(Box::new(res)), is_owned: true }}", struct_for).unwrap();
-                               writeln!(w, "\t}} else {{").unwrap();
-                               writeln!(w, "\t\t{} {{ inner: std::ptr::null_mut(), is_owned: true }}", struct_for).unwrap();
-                               writeln!(w, "\t}}\n}}").unwrap();
-                       }
-               },
-               _ => {},
-       }
-}
-
 /// Convert "impl trait_path for for_ty { .. }" for manually-mapped types (ie (de)serialization)
 fn maybe_convert_trait_impl<W: std::io::Write>(w: &mut W, trait_path: &syn::Path, for_ty: &syn::Type, types: &mut TypeResolver, generics: &GenericTypes) {
        if let Some(t) = types.maybe_resolve_path(&trait_path, Some(generics)) {
@@ -211,14 +179,9 @@ fn write_trait_impl_field_assign<W: std::io::Write>(w: &mut W, trait_path: &str,
 }
 
 /// Write out the impl block for a defined trait struct which has a supertrait
-fn do_write_impl_trait<W: std::io::Write>(w: &mut W, trait_path: &str, trait_name: &syn::Ident, for_obj: &str) {
+fn do_write_impl_trait<W: std::io::Write>(w: &mut W, trait_path: &str, _trait_name: &syn::Ident, for_obj: &str) {
+eprintln!("{}", trait_path);
        match trait_path {
-               "util::events::MessageSendEventsProvider" => {
-                       writeln!(w, "impl lightning::{} for {} {{", trait_path, for_obj).unwrap();
-                       writeln!(w, "\tfn get_and_clear_pending_msg_events(&self) -> Vec<lightning::util::events::MessageSendEvent> {{").unwrap();
-                       writeln!(w, "\t\t<crate::{} as lightning::{}>::get_and_clear_pending_msg_events(&self.{})", trait_path, trait_path, trait_name).unwrap();
-                       writeln!(w, "\t}}\n}}").unwrap();
-               },
                "util::ser::Writeable" => {
                        writeln!(w, "impl lightning::{} for {} {{", trait_path, for_obj).unwrap();
                        writeln!(w, "\tfn write<W: lightning::util::ser::Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {{").unwrap();
@@ -289,7 +252,7 @@ fn writeln_trait<'a, 'b, W: std::io::Write>(w: &mut W, t: &'a syn::ItemTrait, ty
        writeln!(w, "\t/// An opaque pointer which is passed to your function implementations as an argument.").unwrap();
        writeln!(w, "\t/// This has no meaning in the LDK, and can be NULL or any other value.").unwrap();
        writeln!(w, "\tpub this_arg: *mut c_void,").unwrap();
-       let mut generated_fields = Vec::new(); // Every field's name except this_arg, used in Clone generation
+       let mut generated_fields = Vec::new(); // Every field's (name, is_clonable) except this_arg, used in Clone generation
        for item in t.items.iter() {
                match item {
                        &syn::TraitItem::Method(ref m) => {
@@ -304,8 +267,8 @@ fn writeln_trait<'a, 'b, W: std::io::Write>(w: &mut W, t: &'a syn::ItemTrait, ty
                                }
                                if m.default.is_some() { unimplemented!(); }
 
-                               gen_types.push_ctx();
-                               assert!(gen_types.learn_generics(&m.sig.generics, types));
+                               let mut meth_gen_types = gen_types.push_ctx();
+                               assert!(meth_gen_types.learn_generics(&m.sig.generics, types));
 
                                writeln_docs(w, &m.attrs, "\t");
 
@@ -322,20 +285,19 @@ fn writeln_trait<'a, 'b, W: std::io::Write>(w: &mut W, t: &'a syn::ItemTrait, ty
                                                // happen) as well as provide an Option<>al function pointer which is
                                                // called when the trait method is called which allows updating on the fly.
                                                write!(w, "\tpub {}: ", m.sig.ident).unwrap();
-                                               generated_fields.push(format!("{}", m.sig.ident));
-                                               types.write_c_type(w, &*r.elem, Some(&gen_types), false);
+                                               generated_fields.push((format!("{}", m.sig.ident), true));
+                                               types.write_c_type(w, &*r.elem, Some(&meth_gen_types), false);
                                                writeln!(w, ",").unwrap();
                                                writeln!(w, "\t/// Fill in the {} field as a reference to it will be given to Rust after this returns", m.sig.ident).unwrap();
                                                writeln!(w, "\t/// Note that this takes a pointer to this object, not the this_ptr like other methods do").unwrap();
                                                writeln!(w, "\t/// This function pointer may be NULL if {} is filled in when this object is created and never needs updating.", m.sig.ident).unwrap();
                                                writeln!(w, "\tpub set_{}: Option<extern \"C\" fn(&{})>,", m.sig.ident, trait_name).unwrap();
-                                               generated_fields.push(format!("set_{}", m.sig.ident));
+                                               generated_fields.push((format!("set_{}", m.sig.ident), true));
                                                // Note that cbindgen will now generate
                                                // typedef struct Thing {..., set_thing: (const Thing*), ...} Thing;
                                                // which does not compile since Thing is not defined before it is used.
                                                writeln!(extra_headers, "struct LDK{};", trait_name).unwrap();
                                                writeln!(extra_headers, "typedef struct LDK{} LDK{};", trait_name, trait_name).unwrap();
-                                               gen_types.pop_ctx();
                                                continue;
                                        }
                                        // Sadly, this currently doesn't do what we want, but it should be easy to get
@@ -344,36 +306,39 @@ fn writeln_trait<'a, 'b, W: std::io::Write>(w: &mut W, t: &'a syn::ItemTrait, ty
                                }
 
                                write!(w, "\tpub {}: extern \"C\" fn (", m.sig.ident).unwrap();
-                               generated_fields.push(format!("{}", m.sig.ident));
-                               write_method_params(w, &m.sig, "c_void", types, Some(&gen_types), true, false);
+                               generated_fields.push((format!("{}", m.sig.ident), true));
+                               write_method_params(w, &m.sig, "c_void", types, Some(&meth_gen_types), true, false);
                                writeln!(w, ",").unwrap();
-
-                               gen_types.pop_ctx();
                        },
                        &syn::TraitItem::Type(_) => {},
                        _ => unimplemented!(),
                }
        }
        // Add functions which may be required for supertrait implementations.
+       let mut requires_clone = false;
+       walk_supertraits!(t, Some(&types), (
+               ("Clone", _) => requires_clone = true,
+               (_, _) => {}
+       ) );
        walk_supertraits!(t, Some(&types), (
                ("Clone", _) => {
                        writeln!(w, "\t/// Creates a copy of the object pointed to by this_arg, for a copy of this {}.", trait_name).unwrap();
                        writeln!(w, "\t/// Note that the ultimate copy of the {} will have all function pointers the same as the original.", trait_name).unwrap();
                        writeln!(w, "\t/// May be NULL if no action needs to be taken, the this_arg pointer will be copied into the new {}.", trait_name).unwrap();
                        writeln!(w, "\tpub clone: Option<extern \"C\" fn (this_arg: *const c_void) -> *mut c_void>,").unwrap();
-                       generated_fields.push("clone".to_owned());
+                       generated_fields.push(("clone".to_owned(), true));
                },
                ("std::cmp::Eq", _) => {
                        writeln!(w, "\t/// Checks if two objects are equal given this object's this_arg pointer and another object.").unwrap();
                        writeln!(w, "\tpub eq: extern \"C\" fn (this_arg: *const c_void, other_arg: &{}) -> bool,", trait_name).unwrap();
                        writeln!(extra_headers, "typedef struct LDK{} LDK{};", trait_name, trait_name).unwrap();
-                       generated_fields.push("eq".to_owned());
+                       generated_fields.push(("eq".to_owned(), true));
                },
                ("std::hash::Hash", _) => {
                        writeln!(w, "\t/// Calculate a succinct non-cryptographic hash for an object given its this_arg pointer.").unwrap();
                        writeln!(w, "\t/// This is used, for example, for inclusion of this object in a hash map.").unwrap();
                        writeln!(w, "\tpub hash: extern \"C\" fn (this_arg: *const c_void) -> u64,").unwrap();
-                       generated_fields.push("hash".to_owned());
+                       generated_fields.push(("hash".to_owned(), true));
                },
                ("Send", _) => {}, ("Sync", _) => {},
                (s, i) => {
@@ -381,20 +346,125 @@ fn writeln_trait<'a, 'b, W: std::io::Write>(w: &mut W, t: &'a syn::ItemTrait, ty
                                let (docs, name, ret) = convert_trait_impl_field(s);
                                writeln!(w, "\t/// {}", docs).unwrap();
                                writeln!(w, "\tpub {}: extern \"C\" fn (this_arg: *const c_void) -> {},", name, ret).unwrap();
-                               name
+                               (name, true) // Assume clonable
                        } else {
                                // For in-crate supertraits, just store a C-mapped copy of the supertrait as a member.
-                               writeln!(w, "/// Implementation of {} for this object.", i).unwrap();
+                               writeln!(w, "\t/// Implementation of {} for this object.", i).unwrap();
                                writeln!(w, "\tpub {}: crate::{},", i, s).unwrap();
-                               format!("{}", i)
+                               let is_clonable = types.is_clonable(s);
+                               if !is_clonable && requires_clone {
+                                       writeln!(w, "\t/// Creates a copy of the {}, for a copy of this {}.", i, trait_name).unwrap();
+                                       writeln!(w, "\t/// Because {} doesn't natively support copying itself, you have to provide a full copy implementation here.", i).unwrap();
+                                       writeln!(w, "\tpub {}_clone: extern \"C\" fn (orig_{}: &{}) -> {},", i, i, i, i).unwrap();
+                               }
+                               (format!("{}", i), is_clonable)
                        });
                }
        ) );
        writeln!(w, "\t/// Frees any resources associated with this object given its this_arg pointer.").unwrap();
        writeln!(w, "\t/// Does not need to free the outer struct containing function pointers and may be NULL is no resources need to be freed.").unwrap();
        writeln!(w, "\tpub free: Option<extern \"C\" fn(this_arg: *mut c_void)>,").unwrap();
-       generated_fields.push("free".to_owned());
+       generated_fields.push(("free".to_owned(), true));
        writeln!(w, "}}").unwrap();
+
+       macro_rules! impl_trait_for_c {
+               ($t: expr, $impl_accessor: expr, $type_resolver: expr) => {
+                       for item in $t.items.iter() {
+                               match item {
+                                       syn::TraitItem::Method(m) => {
+                                               if let ExportStatus::TestOnly = export_status(&m.attrs) { continue; }
+                                               if m.default.is_some() { unimplemented!(); }
+                                               if m.sig.constness.is_some() || m.sig.asyncness.is_some() || m.sig.unsafety.is_some() ||
+                                                               m.sig.abi.is_some() || m.sig.variadic.is_some() {
+                                                       unimplemented!();
+                                               }
+                                               let mut meth_gen_types = gen_types.push_ctx();
+                                               assert!(meth_gen_types.learn_generics(&m.sig.generics, $type_resolver));
+                                               write!(w, "\tfn {}", m.sig.ident).unwrap();
+                                               $type_resolver.write_rust_generic_param(w, Some(&meth_gen_types), m.sig.generics.params.iter());
+                                               write!(w, "(").unwrap();
+                                               for inp in m.sig.inputs.iter() {
+                                                       match inp {
+                                                               syn::FnArg::Receiver(recv) => {
+                                                                       if !recv.attrs.is_empty() || recv.reference.is_none() { unimplemented!(); }
+                                                                       write!(w, "&").unwrap();
+                                                                       if let Some(lft) = &recv.reference.as_ref().unwrap().1 {
+                                                                               write!(w, "'{} ", lft.ident).unwrap();
+                                                                       }
+                                                                       if recv.mutability.is_some() {
+                                                                               write!(w, "mut self").unwrap();
+                                                                       } else {
+                                                                               write!(w, "self").unwrap();
+                                                                       }
+                                                               },
+                                                               syn::FnArg::Typed(arg) => {
+                                                                       if !arg.attrs.is_empty() { unimplemented!(); }
+                                                                       match &*arg.pat {
+                                                                               syn::Pat::Ident(ident) => {
+                                                                                       if !ident.attrs.is_empty() || ident.by_ref.is_some() ||
+                                                                                                       ident.mutability.is_some() || ident.subpat.is_some() {
+                                                                                               unimplemented!();
+                                                                                       }
+                                                                                       write!(w, ", {}{}: ", if $type_resolver.skip_arg(&*arg.ty, Some(&meth_gen_types)) { "_" } else { "" }, ident.ident).unwrap();
+                                                                               }
+                                                                               _ => unimplemented!(),
+                                                                       }
+                                                                       $type_resolver.write_rust_type(w, Some(&meth_gen_types), &*arg.ty);
+                                                               }
+                                                       }
+                                               }
+                                               write!(w, ")").unwrap();
+                                               match &m.sig.output {
+                                                       syn::ReturnType::Type(_, rtype) => {
+                                                               write!(w, " -> ").unwrap();
+                                                               $type_resolver.write_rust_type(w, Some(&meth_gen_types), &*rtype)
+                                                       },
+                                                       _ => {},
+                                               }
+                                               write!(w, " {{\n\t\t").unwrap();
+                                               match export_status(&m.attrs) {
+                                                       ExportStatus::NoExport => {
+                                                               unimplemented!();
+                                                       },
+                                                       _ => {},
+                                               }
+                                               if let syn::ReturnType::Type(_, rtype) = &m.sig.output {
+                                                       if let syn::Type::Reference(r) = &**rtype {
+                                                               assert_eq!(m.sig.inputs.len(), 1); // Must only take self!
+                                                               writeln!(w, "if let Some(f) = self{}.set_{} {{", $impl_accessor, m.sig.ident).unwrap();
+                                                               writeln!(w, "\t\t\t(f)(&self{});", $impl_accessor).unwrap();
+                                                               write!(w, "\t\t}}\n\t\t").unwrap();
+                                                               $type_resolver.write_from_c_conversion_to_ref_prefix(w, &*r.elem, Some(&meth_gen_types));
+                                                               write!(w, "self{}.{}", $impl_accessor, m.sig.ident).unwrap();
+                                                               $type_resolver.write_from_c_conversion_to_ref_suffix(w, &*r.elem, Some(&meth_gen_types));
+                                                               writeln!(w, "\n\t}}").unwrap();
+                                                               continue;
+                                                       }
+                                               }
+                                               write_method_var_decl_body(w, &m.sig, "\t", $type_resolver, Some(&meth_gen_types), true);
+                                               write!(w, "(self{}.{})(", $impl_accessor, m.sig.ident).unwrap();
+                                               write_method_call_params(w, &m.sig, "\t", $type_resolver, Some(&meth_gen_types), "", true);
+
+                                               writeln!(w, "\n\t}}").unwrap();
+                                       },
+                                       &syn::TraitItem::Type(ref t) => {
+                                               if t.default.is_some() || t.generics.lt_token.is_some() { unimplemented!(); }
+                                               let mut bounds_iter = t.bounds.iter();
+                                               match bounds_iter.next().unwrap() {
+                                                       syn::TypeParamBound::Trait(tr) => {
+                                                               writeln!(w, "\ttype {} = crate::{};", t.ident, $type_resolver.resolve_path(&tr.path, Some(&gen_types))).unwrap();
+                                                       },
+                                                       _ => unimplemented!(),
+                                               }
+                                               if bounds_iter.next().is_some() { unimplemented!(); }
+                                       },
+                                       _ => unimplemented!(),
+                               }
+                       }
+               }
+       }
+
+
        // Implement supertraits for the C-mapped struct.
        walk_supertraits!(t, Some(&types), (
                ("Send", _) => writeln!(w, "unsafe impl Send for {} {{}}", trait_name).unwrap(),
@@ -414,8 +484,13 @@ fn writeln_trait<'a, 'b, W: std::io::Write>(w: &mut W, t: &'a syn::ItemTrait, ty
                        writeln!(w, "pub extern \"C\" fn {}_clone(orig: &{}) -> {} {{", trait_name, trait_name, trait_name).unwrap();
                        writeln!(w, "\t{} {{", trait_name).unwrap();
                        writeln!(w, "\t\tthis_arg: if let Some(f) = orig.clone {{ (f)(orig.this_arg) }} else {{ orig.this_arg }},").unwrap();
-                       for field in generated_fields.iter() {
-                               writeln!(w, "\t\t{}: orig.{}.clone(),", field, field).unwrap();
+                       for (field, clonable) in generated_fields.iter() {
+                               if *clonable {
+                                       writeln!(w, "\t\t{}: Clone::clone(&orig.{}),", field, field).unwrap();
+                               } else {
+                                       writeln!(w, "\t\t{}: (orig.{}_clone)(&orig.{}),", field, field, field).unwrap();
+                                       writeln!(w, "\t\t{}_clone: orig.{}_clone,", field, field).unwrap();
+                               }
                        }
                        writeln!(w, "\t}}\n}}").unwrap();
                        writeln!(w, "impl Clone for {} {{", trait_name).unwrap();
@@ -424,7 +499,23 @@ fn writeln_trait<'a, 'b, W: std::io::Write>(w: &mut W, t: &'a syn::ItemTrait, ty
                        writeln!(w, "\t}}\n}}").unwrap();
                },
                (s, i) => {
-                       do_write_impl_trait(w, s, i, &trait_name);
+                       if let Some(supertrait) = types.crate_types.traits.get(s) {
+                               let mut module_iter = s.rsplitn(2, "::");
+                               module_iter.next().unwrap();
+                               let supertrait_module = module_iter.next().unwrap();
+                               let imports = ImportResolver::new(supertrait_module, &types.crate_types.lib_ast.modules.get(supertrait_module).unwrap().items);
+                               let resolver = TypeResolver::new("lightning", &supertrait_module, imports, types.crate_types); // TODO: Drop hard-coded crate name here
+                               writeln!(w, "impl lightning::{} for {} {{", s, trait_name).unwrap(); // TODO: Drop hard-coded crate name here
+                               impl_trait_for_c!(supertrait, format!(".{}", i), &resolver);
+                               writeln!(w, "}}").unwrap();
+                               walk_supertraits!(supertrait, Some(&types), (
+                                       ("Send", _) => writeln!(w, "unsafe impl Send for {} {{}}", trait_name).unwrap(),
+                                       ("Sync", _) => writeln!(w, "unsafe impl Sync for {} {{}}", trait_name).unwrap(),
+                                       _ => unimplemented!()
+                               ) );
+                       } else {
+                               do_write_impl_trait(w, s, i, &trait_name);
+                       }
                }
        ) );
 
@@ -433,100 +524,7 @@ fn writeln_trait<'a, 'b, W: std::io::Write>(w: &mut W, t: &'a syn::ItemTrait, ty
        write!(w, "impl rust{}", t.ident).unwrap();
        maybe_write_generics(w, &t.generics, types, false);
        writeln!(w, " for {} {{", trait_name).unwrap();
-       for item in t.items.iter() {
-               match item {
-                       syn::TraitItem::Method(m) => {
-                               if let ExportStatus::TestOnly = export_status(&m.attrs) { continue; }
-                               if m.default.is_some() { unimplemented!(); }
-                               if m.sig.constness.is_some() || m.sig.asyncness.is_some() || m.sig.unsafety.is_some() ||
-                                               m.sig.abi.is_some() || m.sig.variadic.is_some() {
-                                       unimplemented!();
-                               }
-                               gen_types.push_ctx();
-                               assert!(gen_types.learn_generics(&m.sig.generics, types));
-                               write!(w, "\tfn {}", m.sig.ident).unwrap();
-                               types.write_rust_generic_param(w, Some(&gen_types), m.sig.generics.params.iter());
-                               write!(w, "(").unwrap();
-                               for inp in m.sig.inputs.iter() {
-                                       match inp {
-                                               syn::FnArg::Receiver(recv) => {
-                                                       if !recv.attrs.is_empty() || recv.reference.is_none() { unimplemented!(); }
-                                                       write!(w, "&").unwrap();
-                                                       if let Some(lft) = &recv.reference.as_ref().unwrap().1 {
-                                                               write!(w, "'{} ", lft.ident).unwrap();
-                                                       }
-                                                       if recv.mutability.is_some() {
-                                                               write!(w, "mut self").unwrap();
-                                                       } else {
-                                                               write!(w, "self").unwrap();
-                                                       }
-                                               },
-                                               syn::FnArg::Typed(arg) => {
-                                                       if !arg.attrs.is_empty() { unimplemented!(); }
-                                                       match &*arg.pat {
-                                                               syn::Pat::Ident(ident) => {
-                                                                       if !ident.attrs.is_empty() || ident.by_ref.is_some() ||
-                                                                                       ident.mutability.is_some() || ident.subpat.is_some() {
-                                                                               unimplemented!();
-                                                                       }
-                                                                       write!(w, ", {}{}: ", if types.skip_arg(&*arg.ty, Some(&gen_types)) { "_" } else { "" }, ident.ident).unwrap();
-                                                               }
-                                                               _ => unimplemented!(),
-                                                       }
-                                                       types.write_rust_type(w, Some(&gen_types), &*arg.ty);
-                                               }
-                                       }
-                               }
-                               write!(w, ")").unwrap();
-                               match &m.sig.output {
-                                       syn::ReturnType::Type(_, rtype) => {
-                                               write!(w, " -> ").unwrap();
-                                               types.write_rust_type(w, Some(&gen_types), &*rtype)
-                                       },
-                                       _ => {},
-                               }
-                               write!(w, " {{\n\t\t").unwrap();
-                               match export_status(&m.attrs) {
-                                       ExportStatus::NoExport => {
-                                               unimplemented!();
-                                       },
-                                       _ => {},
-                               }
-                               if let syn::ReturnType::Type(_, rtype) = &m.sig.output {
-                                       if let syn::Type::Reference(r) = &**rtype {
-                                               assert_eq!(m.sig.inputs.len(), 1); // Must only take self!
-                                               writeln!(w, "if let Some(f) = self.set_{} {{", m.sig.ident).unwrap();
-                                               writeln!(w, "\t\t\t(f)(self);").unwrap();
-                                               write!(w, "\t\t}}\n\t\t").unwrap();
-                                               types.write_from_c_conversion_to_ref_prefix(w, &*r.elem, Some(&gen_types));
-                                               write!(w, "self.{}", m.sig.ident).unwrap();
-                                               types.write_from_c_conversion_to_ref_suffix(w, &*r.elem, Some(&gen_types));
-                                               writeln!(w, "\n\t}}").unwrap();
-                                               gen_types.pop_ctx();
-                                               continue;
-                                       }
-                               }
-                               write_method_var_decl_body(w, &m.sig, "\t", types, Some(&gen_types), true);
-                               write!(w, "(self.{})(", m.sig.ident).unwrap();
-                               write_method_call_params(w, &m.sig, "\t", types, Some(&gen_types), "", true);
-
-                               writeln!(w, "\n\t}}").unwrap();
-                               gen_types.pop_ctx();
-                       },
-                       &syn::TraitItem::Type(ref t) => {
-                               if t.default.is_some() || t.generics.lt_token.is_some() { unimplemented!(); }
-                               let mut bounds_iter = t.bounds.iter();
-                               match bounds_iter.next().unwrap() {
-                                       syn::TypeParamBound::Trait(tr) => {
-                                               writeln!(w, "\ttype {} = crate::{};", t.ident, types.resolve_path(&tr.path, Some(&gen_types))).unwrap();
-                                       },
-                                       _ => unimplemented!(),
-                               }
-                               if bounds_iter.next().is_some() { unimplemented!(); }
-                       },
-                       _ => unimplemented!(),
-               }
-       }
+       impl_trait_for_c!(t, "", types);
        writeln!(w, "}}\n").unwrap();
        writeln!(w, "// We're essentially a pointer already, or at least a set of pointers, so allow us to be used").unwrap();
        writeln!(w, "// directly as a Deref trait in higher-level structs:").unwrap();
@@ -802,12 +800,12 @@ fn writeln_impl<W: std::io::Write>(w: &mut W, i: &syn::ItemImpl, types: &mut Typ
                                                                        if let syn::Type::Reference(r) = &**rtype {
                                                                                write!(w, "\n\t\t{}{}: ", $indent, $m.sig.ident).unwrap();
                                                                                types.write_empty_rust_val(Some(&gen_types), w, &*r.elem);
-                                                                               writeln!(w, ",\n{}\t\tset_{}: Some({}_{}_set_{}),", $indent, $m.sig.ident, ident, trait_obj.ident, $m.sig.ident).unwrap();
+                                                                               writeln!(w, ",\n{}\t\tset_{}: Some({}_{}_set_{}),", $indent, $m.sig.ident, ident, $trait.ident, $m.sig.ident).unwrap();
                                                                                printed = true;
                                                                        }
                                                                }
                                                                if !printed {
-                                                                       write!(w, "{}\t\t{}: {}_{}_{},\n", $indent, $m.sig.ident, ident, trait_obj.ident, $m.sig.ident).unwrap();
+                                                                       write!(w, "{}\t\t{}: {}_{}_{},\n", $indent, $m.sig.ident, ident, $trait.ident, $m.sig.ident).unwrap();
                                                                }
                                                        }
                                                }
@@ -819,6 +817,11 @@ fn writeln_impl<W: std::io::Write>(w: &mut W, i: &syn::ItemImpl, types: &mut Typ
                                                                _ => {},
                                                        }
                                                }
+                                               let mut requires_clone = false;
+                                               walk_supertraits!(trait_obj, Some(&types), (
+                                                       ("Clone", _) => requires_clone = true,
+                                                       (_, _) => {}
+                                               ) );
                                                walk_supertraits!(trait_obj, Some(&types), (
                                                        ("Clone", _) => {
                                                                writeln!(w, "\t\tclone: Some({}_clone_void),", ident).unwrap();
@@ -839,6 +842,9 @@ fn writeln_impl<W: std::io::Write>(w: &mut W, i: &syn::ItemImpl, types: &mut Typ
                                                                                }
                                                                        }
                                                                        write!(w, "\t\t}},\n").unwrap();
+                                                                       if !types.is_clonable(s) && requires_clone {
+                                                                               writeln!(w, "\t\t{}_clone: {}_{}_clone,", t, ident, t).unwrap();
+                                                                       }
                                                                } else {
                                                                        write_trait_impl_field_assign(w, s, ident);
                                                                }
@@ -859,12 +865,12 @@ fn writeln_impl<W: std::io::Write>(w: &mut W, i: &syn::ItemImpl, types: &mut Typ
                                                                if let syn::ReturnType::Type(_, _) = &$m.sig.output {
                                                                        writeln!(w, "#[must_use]").unwrap();
                                                                }
-                                                               write!(w, "extern \"C\" fn {}_{}_{}(", ident, trait_obj.ident, $m.sig.ident).unwrap();
-                                                               gen_types.push_ctx();
-                                                               assert!(gen_types.learn_generics(&$m.sig.generics, types));
-                                                               write_method_params(w, &$m.sig, "c_void", types, Some(&gen_types), true, true);
+                                                               write!(w, "extern \"C\" fn {}_{}_{}(", ident, $trait.ident, $m.sig.ident).unwrap();
+                                                               let mut meth_gen_types = gen_types.push_ctx();
+                                                               assert!(meth_gen_types.learn_generics(&$m.sig.generics, types));
+                                                               write_method_params(w, &$m.sig, "c_void", types, Some(&meth_gen_types), true, true);
                                                                write!(w, " {{\n\t").unwrap();
-                                                               write_method_var_decl_body(w, &$m.sig, "", types, Some(&gen_types), false);
+                                                               write_method_var_decl_body(w, &$m.sig, "", types, Some(&meth_gen_types), false);
                                                                let mut takes_self = false;
                                                                for inp in $m.sig.inputs.iter() {
                                                                        if let syn::FnArg::Receiver(_) = inp {
@@ -894,19 +900,18 @@ fn writeln_impl<W: std::io::Write>(w: &mut W, i: &syn::ItemImpl, types: &mut Typ
                                                                        },
                                                                        _ => {},
                                                                }
-                                                               write_method_call_params(w, &$m.sig, "", types, Some(&gen_types), &real_type, false);
-                                                               gen_types.pop_ctx();
+                                                               write_method_call_params(w, &$m.sig, "", types, Some(&meth_gen_types), &real_type, false);
                                                                write!(w, "\n}}\n").unwrap();
                                                                if let syn::ReturnType::Type(_, rtype) = &$m.sig.output {
                                                                        if let syn::Type::Reference(r) = &**rtype {
                                                                                assert_eq!($m.sig.inputs.len(), 1); // Must only take self
-                                                                               writeln!(w, "extern \"C\" fn {}_{}_set_{}(trait_self_arg: &{}) {{", ident, trait_obj.ident, $m.sig.ident, trait_obj.ident).unwrap();
+                                                                               writeln!(w, "extern \"C\" fn {}_{}_set_{}(trait_self_arg: &{}) {{", ident, $trait.ident, $m.sig.ident, $trait.ident).unwrap();
                                                                                writeln!(w, "\t// This is a bit race-y in the general case, but for our specific use-cases today, we're safe").unwrap();
                                                                                writeln!(w, "\t// Specifically, we must ensure that the first time we're called it can never be in parallel").unwrap();
                                                                                write!(w, "\tif ").unwrap();
-                                                                               types.write_empty_rust_val_check(Some(&gen_types), w, &*r.elem, &format!("trait_self_arg.{}", $m.sig.ident));
+                                                                               types.write_empty_rust_val_check(Some(&meth_gen_types), w, &*r.elem, &format!("trait_self_arg.{}", $m.sig.ident));
                                                                                writeln!(w, " {{").unwrap();
-                                                                               writeln!(w, "\t\tunsafe {{ &mut *(trait_self_arg as *const {}  as *mut {}) }}.{} = {}_{}_{}(trait_self_arg.this_arg);", trait_obj.ident, trait_obj.ident, $m.sig.ident, ident, trait_obj.ident, $m.sig.ident).unwrap();
+                                                                               writeln!(w, "\t\tunsafe {{ &mut *(trait_self_arg as *const {}  as *mut {}) }}.{} = {}_{}_{}(trait_self_arg.this_arg);", $trait.ident, $trait.ident, $m.sig.ident, ident, $trait.ident, $m.sig.ident).unwrap();
                                                                                writeln!(w, "\t}}").unwrap();
                                                                                writeln!(w, "}}").unwrap();
                                                                        }
@@ -924,15 +929,22 @@ fn writeln_impl<W: std::io::Write>(w: &mut W, i: &syn::ItemImpl, types: &mut Typ
                                                        }
                                                }
                                                walk_supertraits!(trait_obj, Some(&types), (
-                                                       (s, _) => {
-                                                               if let Some(supertrait_obj) = types.crate_types.traits.get(s).cloned() {
-                                                                       for item in supertrait_obj.items.iter() {
-                                                                               match item {
-                                                                                       syn::TraitItem::Method(m) => {
-                                                                                               impl_meth!(m, s, supertrait_obj, "\t");
-                                                                                       },
-                                                                                       _ => {},
+                                                       (s, t) => {
+                                                               if let Some(supertrait_obj) = types.crate_types.traits.get(s) {
+                                                                       if !types.is_clonable(s) && requires_clone {
+                                                                               writeln!(w, "extern \"C\" fn {}_{}_clone(orig: &crate::{}) -> crate::{} {{", ident, t, s, s).unwrap();
+                                                                               writeln!(w, "\tcrate::{} {{", s).unwrap();
+                                                                               writeln!(w, "\t\tthis_arg: orig.this_arg,").unwrap();
+                                                                               writeln!(w, "\t\tfree: None,").unwrap();
+                                                                               for item in supertrait_obj.items.iter() {
+                                                                                       match item {
+                                                                                               syn::TraitItem::Method(m) => {
+                                                                                                       write_meth!(m, supertrait_obj, "");
+                                                                                               },
+                                                                                               _ => {},
+                                                                                       }
                                                                                }
+                                                                               write!(w, "\t}}\n}}\n").unwrap();
                                                                        }
                                                                }
                                                        }
@@ -990,11 +1002,11 @@ fn writeln_impl<W: std::io::Write>(w: &mut W, i: &syn::ItemImpl, types: &mut Typ
                                                                                DeclType::StructImported => format!("{}", ident),
                                                                                _ => unimplemented!(),
                                                                        };
-                                                                       gen_types.push_ctx();
-                                                                       assert!(gen_types.learn_generics(&m.sig.generics, types));
-                                                                       write_method_params(w, &m.sig, &ret_type, types, Some(&gen_types), false, true);
+                                                                       let mut meth_gen_types = gen_types.push_ctx();
+                                                                       assert!(meth_gen_types.learn_generics(&m.sig.generics, types));
+                                                                       write_method_params(w, &m.sig, &ret_type, types, Some(&meth_gen_types), false, true);
                                                                        write!(w, " {{\n\t").unwrap();
-                                                                       write_method_var_decl_body(w, &m.sig, "", types, Some(&gen_types), false);
+                                                                       write_method_var_decl_body(w, &m.sig, "", types, Some(&meth_gen_types), false);
                                                                        let mut takes_self = false;
                                                                        let mut takes_mut_self = false;
                                                                        for inp in m.sig.inputs.iter() {
@@ -1010,8 +1022,7 @@ fn writeln_impl<W: std::io::Write>(w: &mut W, i: &syn::ItemImpl, types: &mut Typ
                                                                        } else {
                                                                                write!(w, "{}::{}::{}(", types.orig_crate, resolved_path, m.sig.ident).unwrap();
                                                                        }
-                                                                       write_method_call_params(w, &m.sig, "", types, Some(&gen_types), &ret_type, false);
-                                                                       gen_types.pop_ctx();
+                                                                       write_method_call_params(w, &m.sig, "", types, Some(&meth_gen_types), &ret_type, false);
                                                                        writeln!(w, "\n}}\n").unwrap();
                                                                }
                                                        },
@@ -1284,57 +1295,11 @@ fn writeln_fn<'a, 'b, W: std::io::Write>(w: &mut W, f: &'a syn::ItemFn, types: &
 // ********************************
 // *** File/Crate Walking Logic ***
 // ********************************
-/// A public module
-struct ASTModule {
-       pub attrs: Vec<syn::Attribute>,
-       pub items: Vec<syn::Item>,
-       pub submods: Vec<String>,
-}
-/// A struct containing the syn::File AST for each file in the crate.
-struct FullLibraryAST {
-       modules: HashMap<String, ASTModule, NonRandomHash>,
-}
-impl FullLibraryAST {
-       fn load_module(&mut self, module: String, attrs: Vec<syn::Attribute>, mut items: Vec<syn::Item>) {
-               let mut non_mod_items = Vec::with_capacity(items.len());
-               let mut submods = Vec::with_capacity(items.len());
-               for item in items.drain(..) {
-                       match item {
-                               syn::Item::Mod(m) if m.content.is_some() => {
-                                       if export_status(&m.attrs) == ExportStatus::Export {
-                                               if let syn::Visibility::Public(_) = m.vis {
-                                                       let modident = format!("{}", m.ident);
-                                                       let modname = if module != "" {
-                                                               module.clone() + "::" + &modident
-                                                       } else {
-                                                               modident.clone()
-                                                       };
-                                                       self.load_module(modname, m.attrs, m.content.unwrap().1);
-                                                       submods.push(modident);
-                                               } else {
-                                                       non_mod_items.push(syn::Item::Mod(m));
-                                               }
-                                       }
-                               },
-                               syn::Item::Mod(_) => panic!("--pretty=expanded output should never have non-body modules"),
-                               _ => { non_mod_items.push(item); }
-                       }
-               }
-               self.modules.insert(module, ASTModule { attrs, items: non_mod_items, submods });
-       }
-
-       pub fn load_lib(lib: syn::File) -> Self {
-               assert_eq!(export_status(&lib.attrs), ExportStatus::Export);
-               let mut res = Self { modules: HashMap::default() };
-               res.load_module("".to_owned(), lib.attrs, lib.items);
-               res
-       }
-}
 
 /// Do the Real Work of mapping an original file to C-callable wrappers. Creates a new file at
 /// `out_path` and fills it with wrapper structs/functions to allow calling the things in the AST
 /// at `module` from C.
-fn convert_file<'a, 'b>(libast: &'a FullLibraryAST, crate_types: &mut CrateTypes<'a>, out_dir: &str, orig_crate: &str, header_file: &mut File, cpp_header_file: &mut File) {
+fn convert_file<'a, 'b>(libast: &'a FullLibraryAST, crate_types: &CrateTypes<'a>, out_dir: &str, orig_crate: &str, header_file: &mut File, cpp_header_file: &mut File) {
        for (module, astmod) in libast.modules.iter() {
                let ASTModule { ref attrs, ref items, ref submods } = astmod;
                assert_eq!(export_status(&attrs), ExportStatus::Export);
@@ -1451,11 +1416,7 @@ fn convert_file<'a, 'b>(libast: &'a FullLibraryAST, crate_types: &mut CrateTypes
                                                writeln_fn(&mut out, &f, &mut type_resolver);
                                        }
                                },
-                               syn::Item::Macro(m) => {
-                                       if m.ident.is_none() { // If its not a macro definition
-                                               convert_macro(&mut out, &m.mac.path, &m.mac.tokens, &type_resolver);
-                                       }
-                               },
+                               syn::Item::Macro(_) => {},
                                syn::Item::Verbatim(_) => {},
                                syn::Item::ExternCrate(_) => {},
                                _ => unimplemented!(),
@@ -1518,7 +1479,7 @@ fn walk_ast<'a>(ast_storage: &'a FullLibraryAST, crate_types: &mut CrateTypes<'a
                                                let trait_path = format!("{}::{}", module, t.ident);
                                                walk_supertraits!(t, None, (
                                                        ("Clone", _) => {
-                                                               crate_types.clonable_types.insert("crate::".to_owned() + &trait_path);
+                                                               crate_types.set_clonable("crate::".to_owned() + &trait_path);
                                                        },
                                                        (_, _) => {}
                                                ) );
@@ -1587,7 +1548,7 @@ fn walk_ast<'a>(ast_storage: &'a FullLibraryAST, crate_types: &mut CrateTypes<'a
                                                if let Some(trait_path) = i.trait_.as_ref() {
                                                        if path_matches_nongeneric(&trait_path.1, &["core", "clone", "Clone"]) {
                                                                if let Some(full_path) = import_resolver.maybe_resolve_path(&p.path, None) {
-                                                                       crate_types.clonable_types.insert("crate::".to_owned() + &full_path);
+                                                                       crate_types.set_clonable("crate::".to_owned() + &full_path);
                                                                }
                                                        }
                                                        if let Some(tp) = import_resolver.maybe_resolve_path(&trait_path.1, None) {
@@ -1645,18 +1606,15 @@ fn main() {
 
        // ...then walk the ASTs tracking what types we will map, and how, so that we can resolve them
        // when parsing other file ASTs...
-       let mut libtypes = CrateTypes { traits: HashMap::new(), opaques: HashMap::new(), mirrored_enums: HashMap::new(),
-               type_aliases: HashMap::new(), reverse_alias_map: HashMap::new(), templates_defined: HashMap::default(),
-               template_file: &mut derived_templates,
-               clonable_types: HashSet::new(), trait_impls: HashMap::new() };
+       let mut libtypes = CrateTypes::new(&mut derived_templates, &libast);
        walk_ast(&libast, &mut libtypes);
 
        // ... finally, do the actual file conversion/mapping, writing out types as we go.
-       convert_file(&libast, &mut libtypes, &args[1], &args[2], &mut header_file, &mut cpp_header_file);
+       convert_file(&libast, &libtypes, &args[1], &args[2], &mut header_file, &mut cpp_header_file);
 
        // For container templates which we created while walking the crate, make sure we add C++
        // mapped types so that C++ users can utilize the auto-destructors available.
-       for (ty, has_destructor) in libtypes.templates_defined.iter() {
+       for (ty, has_destructor) in libtypes.templates_defined.borrow().iter() {
                write_cpp_wrapper(&mut cpp_header_file, ty, *has_destructor);
        }
        writeln!(cpp_header_file, "}}").unwrap();