Support mapping core::fmt::Debug as a supertrait
[ldk-c-bindings] / c-bindings-gen / src / main.rs
index 2f94e432e4f351c36e8f975cb531d1d57258f7ba..9cd32feb8f7bfe6d1ebeee93e076cfa25c0bf82f 100644 (file)
@@ -163,7 +163,6 @@ 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) {
-eprintln!("{}", trait_path);
        match trait_path {
                "lightning::util::ser::Writeable" => {
                        writeln!(w, "impl {} for {} {{", trait_path, for_obj).unwrap();
@@ -330,6 +329,13 @@ fn writeln_trait<'a, 'b, W: std::io::Write>(w: &mut W, t: &'a syn::ItemTrait, ty
                                Some(format!("\t/**\n\t * {}\n\t * {}\n\t */\n", hash_docs_a, hash_docs_b))));
                },
                ("Send", _) => {}, ("Sync", _) => {},
+               ("std::fmt::Debug", _)|("core::fmt::Debug", _) => {
+                       let debug_docs = "Return a human-readable \"debug\" string describing this object";
+                       writeln!(w, "\t/// {}", debug_docs).unwrap();
+                       writeln!(w, "\tpub debug_str: extern \"C\" fn (this_arg: *const c_void) -> crate::c_types::Str,").unwrap();
+                       generated_fields.push(("debug_str".to_owned(), None,
+                               Some(format!("\t/**\n\t * {}\n\t */\n", debug_docs))));
+               },
                (s, i) => {
                        // TODO: Both of the below should expose supertrait methods in C++, but doing so is
                        // nontrivial.
@@ -495,6 +501,13 @@ fn writeln_trait<'a, 'b, W: std::io::Write>(w: &mut W, t: &'a syn::ItemTrait, ty
                        writeln!(w, "\t\t{}_clone(self)", trait_name).unwrap();
                        writeln!(w, "\t}}\n}}").unwrap();
                },
+               ("std::fmt::Debug", _)|("core::fmt::Debug", _) => {
+                       writeln!(w, "impl core::fmt::Debug for {} {{", trait_name).unwrap();
+                       writeln!(w, "\tfn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {{").unwrap();
+                       writeln!(w, "\t\tf.write_str((self.debug_str)(self.this_arg).into_str())").unwrap();
+                       writeln!(w, "\t}}").unwrap();
+                       writeln!(w, "}}").unwrap();
+               },
                (s, i) => {
                        if let Some(supertrait) = types.crate_types.traits.get(s) {
                                let mut module_iter = s.rsplitn(2, "::");
@@ -563,7 +576,7 @@ fn writeln_opaque<W: std::io::Write>(w: &mut W, ident: &syn::Ident, struct_name:
        writeln!(w, "}}\n").unwrap();
        writeln!(w, "impl Drop for {} {{\n\tfn drop(&mut self) {{", struct_name).unwrap();
        writeln!(w, "\t\tif self.is_owned && !<*mut native{}>::is_null(self.inner) {{", ident).unwrap();
-       writeln!(w, "\t\t\tlet _ = unsafe {{ Box::from_raw(self.inner) }};\n\t\t}}\n\t}}\n}}").unwrap();
+       writeln!(w, "\t\t\tlet _ = unsafe {{ Box::from_raw(ObjOps::untweak_ptr(self.inner)) }};\n\t\t}}\n\t}}\n}}").unwrap();
        writeln!(w, "/// Frees any resources used by the {}, if is_owned is set and inner is non-NULL.", struct_name).unwrap();
        writeln!(w, "#[no_mangle]\npub extern \"C\" fn {}_free(this_obj: {}) {{ }}", struct_name, struct_name).unwrap();
        writeln!(w, "#[allow(unused)]").unwrap();
@@ -571,11 +584,17 @@ fn writeln_opaque<W: std::io::Write>(w: &mut W, ident: &syn::Ident, struct_name:
        writeln!(w, "extern \"C\" fn {}_free_void(this_ptr: *mut c_void) {{", struct_name).unwrap();
        writeln!(w, "\tunsafe {{ let _ = Box::from_raw(this_ptr as *mut native{}); }}\n}}", struct_name).unwrap();
        writeln!(w, "#[allow(unused)]").unwrap();
-       writeln!(w, "/// When moving out of the pointer, we have to ensure we aren't a reference, this makes that easy").unwrap();
        writeln!(w, "impl {} {{", struct_name).unwrap();
+       writeln!(w, "\tpub(crate) fn get_native_ref(&self) -> &'static native{} {{", struct_name).unwrap();
+       writeln!(w, "\t\tunsafe {{ &*ObjOps::untweak_ptr(self.inner) }}").unwrap();
+       writeln!(w, "\t}}").unwrap();
+       writeln!(w, "\tpub(crate) fn get_native_mut_ref(&self) -> &'static mut native{} {{", struct_name).unwrap();
+       writeln!(w, "\t\tunsafe {{ &mut *ObjOps::untweak_ptr(self.inner) }}").unwrap();
+       writeln!(w, "\t}}").unwrap();
+       writeln!(w, "\t/// When moving out of the pointer, we have to ensure we aren't a reference, this makes that easy").unwrap();
        writeln!(w, "\tpub(crate) fn take_inner(mut self) -> *mut native{} {{", struct_name).unwrap();
        writeln!(w, "\t\tassert!(self.is_owned);").unwrap();
-       writeln!(w, "\t\tlet ret = self.inner;").unwrap();
+       writeln!(w, "\t\tlet ret = ObjOps::untweak_ptr(self.inner);").unwrap();
        writeln!(w, "\t\tself.inner = std::ptr::null_mut();").unwrap();
        writeln!(w, "\t\tret").unwrap();
        writeln!(w, "\t}}\n}}").unwrap();
@@ -613,20 +632,19 @@ fn writeln_struct<'a, 'b, W: std::io::Write>(w: &mut W, s: &'a syn::ItemStruct,
                                }
 
                                if let Some(ident) = &field.ident {
-                                       let ref_type = syn::Type::Reference(syn::TypeReference {
-                                               and_token: syn::Token!(&)(Span::call_site()), lifetime: None, mutability: None,
-                                               elem: Box::new(field.ty.clone()) });
-                                       if types.understood_c_type(&ref_type, Some(&gen_types)) {
-                                               writeln_arg_docs(w, &field.attrs, "", types, Some(&gen_types), vec![].drain(..), Some(&ref_type));
-                                               write!(w, "#[no_mangle]\npub extern \"C\" fn {}_get_{}(this_ptr: &{}) -> ", struct_name, ident, struct_name).unwrap();
-                                               types.write_c_type(w, &ref_type, Some(&gen_types), true);
-                                               write!(w, " {{\n\tlet mut inner_val = &mut unsafe {{ &mut *this_ptr.inner }}.{};\n\t", ident).unwrap();
-                                               let local_var = types.write_to_c_conversion_new_var(w, &format_ident!("inner_val"), &ref_type, Some(&gen_types), true);
-                                               if local_var { write!(w, "\n\t").unwrap(); }
-                                               types.write_to_c_conversion_inline_prefix(w, &ref_type, Some(&gen_types), true);
-                                               write!(w, "inner_val").unwrap();
-                                               types.write_to_c_conversion_inline_suffix(w, &ref_type, Some(&gen_types), true);
-                                               writeln!(w, "\n}}").unwrap();
+                                       if let Some(ref_type) = types.create_ownable_reference(&field.ty, Some(&gen_types)) {
+                                               if types.understood_c_type(&ref_type, Some(&gen_types)) {
+                                                       writeln_arg_docs(w, &field.attrs, "", types, Some(&gen_types), vec![].drain(..), Some(&ref_type));
+                                                       write!(w, "#[no_mangle]\npub extern \"C\" fn {}_get_{}(this_ptr: &{}) -> ", struct_name, ident, struct_name).unwrap();
+                                                       types.write_c_type(w, &ref_type, Some(&gen_types), true);
+                                                       write!(w, " {{\n\tlet mut inner_val = &mut this_ptr.get_native_mut_ref().{};\n\t", ident).unwrap();
+                                                       let local_var = types.write_to_c_conversion_new_var(w, &format_ident!("inner_val"), &ref_type, Some(&gen_types), true);
+                                                       if local_var { write!(w, "\n\t").unwrap(); }
+                                                       types.write_to_c_conversion_inline_prefix(w, &ref_type, Some(&gen_types), true);
+                                                       write!(w, "inner_val").unwrap();
+                                                       types.write_to_c_conversion_inline_suffix(w, &ref_type, Some(&gen_types), true);
+                                                       writeln!(w, "\n}}").unwrap();
+                                               }
                                        }
 
                                        if types.understood_c_type(&field.ty, Some(&gen_types)) {
@@ -636,7 +654,7 @@ fn writeln_struct<'a, 'b, W: std::io::Write>(w: &mut W, s: &'a syn::ItemStruct,
                                                write!(w, ") {{\n\t").unwrap();
                                                let local_var = types.write_from_c_conversion_new_var(w, &format_ident!("val"), &field.ty, Some(&gen_types));
                                                if local_var { write!(w, "\n\t").unwrap(); }
-                                               write!(w, "unsafe {{ &mut *this_ptr.inner }}.{} = ", ident).unwrap();
+                                               write!(w, "unsafe {{ &mut *ObjOps::untweak_ptr(this_ptr.inner) }}.{} = ", ident).unwrap();
                                                types.write_from_c_conversion_prefix(w, &field.ty, Some(&gen_types));
                                                write!(w, "val").unwrap();
                                                types.write_from_c_conversion_suffix(w, &field.ty, Some(&gen_types));
@@ -662,7 +680,7 @@ fn writeln_struct<'a, 'b, W: std::io::Write>(w: &mut W, s: &'a syn::ItemStruct,
                                        write!(w, "\n\t").unwrap();
                                }
                        }
-                       writeln!(w, "{} {{ inner: Box::into_raw(Box::new(native{} {{", struct_name, s.ident).unwrap();
+                       writeln!(w, "{} {{ inner: ObjOps::heap_alloc(native{} {{", struct_name, s.ident).unwrap();
                        for field in fields.named.iter() {
                                write!(w, "\t\t{}: ", field.ident.as_ref().unwrap()).unwrap();
                                types.write_from_c_conversion_prefix(w, &field.ty, Some(&gen_types));
@@ -670,7 +688,7 @@ fn writeln_struct<'a, 'b, W: std::io::Write>(w: &mut W, s: &'a syn::ItemStruct,
                                types.write_from_c_conversion_suffix(w, &field.ty, Some(&gen_types));
                                writeln!(w, ",").unwrap();
                        }
-                       writeln!(w, "\t}})), is_owned: true }}\n}}").unwrap();
+                       writeln!(w, "\t}}), is_owned: true }}\n}}").unwrap();
                }
        }
 }
@@ -764,7 +782,7 @@ fn writeln_impl<W: std::io::Write>(w: &mut W, i: &syn::ItemImpl, types: &mut Typ
                                                // type-conversion logic without actually knowing the concrete native type.
                                                writeln!(w, "impl From<native{}> for crate::{} {{", ident, full_trait_path).unwrap();
                                                writeln!(w, "\tfn from(obj: native{}) -> Self {{", ident).unwrap();
-                                               writeln!(w, "\t\tlet mut rust_obj = {} {{ inner: Box::into_raw(Box::new(obj)), is_owned: true }};", ident).unwrap();
+                                               writeln!(w, "\t\tlet mut rust_obj = {} {{ inner: ObjOps::heap_alloc(obj), is_owned: true }};", ident).unwrap();
                                                writeln!(w, "\t\tlet mut ret = {}_as_{}(&rust_obj);", ident, trait_obj.ident).unwrap();
                                                writeln!(w, "\t\t// We want to free rust_obj when ret gets drop()'d, not rust_obj, so wipe rust_obj's pointer and set ret's free() fn").unwrap();
                                                writeln!(w, "\t\trust_obj.inner = std::ptr::null_mut();").unwrap();
@@ -775,7 +793,7 @@ fn writeln_impl<W: std::io::Write>(w: &mut W, i: &syn::ItemImpl, types: &mut Typ
                                                writeln!(w, "/// This copies the `inner` pointer in this_arg and thus the returned {} must be freed before this_arg is", trait_obj.ident).unwrap();
                                                write!(w, "#[no_mangle]\npub extern \"C\" fn {}_as_{}(this_arg: &{}) -> crate::{} {{\n", ident, trait_obj.ident, ident, full_trait_path).unwrap();
                                                writeln!(w, "\tcrate::{} {{", full_trait_path).unwrap();
-                                               writeln!(w, "\t\tthis_arg: unsafe {{ (*this_arg).inner as *mut c_void }},").unwrap();
+                                               writeln!(w, "\t\tthis_arg: unsafe {{ ObjOps::untweak_ptr((*this_arg).inner) as *mut c_void }},").unwrap();
                                                writeln!(w, "\t\tfree: None,").unwrap();
 
                                                macro_rules! write_meth {
@@ -823,10 +841,11 @@ fn writeln_impl<W: std::io::Write>(w: &mut W, i: &syn::ItemImpl, types: &mut Typ
                                                        },
                                                        ("Sync", _) => {}, ("Send", _) => {},
                                                        ("std::marker::Sync", _) => {}, ("std::marker::Send", _) => {},
+                                                       ("core::fmt::Debug", _) => {},
                                                        (s, t) => {
                                                                if let Some(supertrait_obj) = types.crate_types.traits.get(s) {
                                                                        writeln!(w, "\t\t{}: crate::{} {{", t, s).unwrap();
-                                                                       writeln!(w, "\t\t\tthis_arg: unsafe {{ (*this_arg).inner as *mut c_void }},").unwrap();
+                                                                       writeln!(w, "\t\t\tthis_arg: unsafe {{ ObjOps::untweak_ptr((*this_arg).inner) as *mut c_void }},").unwrap();
                                                                        writeln!(w, "\t\t\tfree: None,").unwrap();
                                                                        for item in supertrait_obj.items.iter() {
                                                                                match item {
@@ -941,7 +960,7 @@ fn writeln_impl<W: std::io::Write>(w: &mut W, i: &syn::ItemImpl, types: &mut Typ
                                        } else if path_matches_nongeneric(&trait_path.1, &["Default"]) {
                                                writeln!(w, "/// Creates a \"default\" {}. See struct and individual field documentaiton for details on which values are used.", ident).unwrap();
                                                write!(w, "#[must_use]\n#[no_mangle]\npub extern \"C\" fn {}_default() -> {} {{\n", ident, ident).unwrap();
-                                               write!(w, "\t{} {{ inner: Box::into_raw(Box::new(Default::default())), is_owned: true }}\n", ident).unwrap();
+                                               write!(w, "\t{} {{ inner: ObjOps::heap_alloc(Default::default()), is_owned: true }}\n", ident).unwrap();
                                                write!(w, "}}\n").unwrap();
                                        } else if path_matches_nongeneric(&trait_path.1, &["core", "cmp", "PartialEq"]) {
                                        } else if path_matches_nongeneric(&trait_path.1, &["core", "cmp", "Eq"]) {
@@ -996,7 +1015,7 @@ fn writeln_impl<W: std::io::Write>(w: &mut W, i: &syn::ItemImpl, types: &mut Typ
                                                writeln!(w, "\tfn clone(&self) -> Self {{").unwrap();
                                                writeln!(w, "\t\tSelf {{").unwrap();
                                                writeln!(w, "\t\t\tinner: if <*mut native{}>::is_null(self.inner) {{ std::ptr::null_mut() }} else {{", ident).unwrap();
-                                               writeln!(w, "\t\t\t\tBox::into_raw(Box::new(unsafe {{ &*self.inner }}.clone())) }},").unwrap();
+                                               writeln!(w, "\t\t\t\tObjOps::heap_alloc(unsafe {{ &*ObjOps::untweak_ptr(self.inner) }}.clone()) }},").unwrap();
                                                writeln!(w, "\t\t\tis_owned: true,").unwrap();
                                                writeln!(w, "\t\t}}\n\t}}\n}}").unwrap();
                                                writeln!(w, "#[allow(unused)]").unwrap();
@@ -1093,9 +1112,9 @@ fn writeln_impl<W: std::io::Write>(w: &mut W, i: &syn::ItemImpl, types: &mut Typ
                                                                                                if takes_owned_self {
                                                                                                        write!(w, "(*unsafe {{ Box::from_raw(this_arg.take_inner()) }}).{}(", m.sig.ident).unwrap();
                                                                                                } else if takes_mut_self {
-                                                                                                       write!(w, "unsafe {{ &mut (*(this_arg.inner as *mut native{})) }}.{}(", ident, m.sig.ident).unwrap();
+                                                                                                       write!(w, "unsafe {{ &mut (*ObjOps::untweak_ptr(this_arg.inner as *mut native{})) }}.{}(", ident, m.sig.ident).unwrap();
                                                                                                } else {
-                                                                                                       write!(w, "unsafe {{ &*this_arg.inner }}.{}(", m.sig.ident).unwrap();
+                                                                                                       write!(w, "unsafe {{ &*ObjOps::untweak_ptr(this_arg.inner) }}.{}(", m.sig.ident).unwrap();
                                                                                                }
                                                                                        },
                                                                                        _ => unimplemented!(),