From 5d83aff2dd572685d7f76406422167e12c836b0e Mon Sep 17 00:00:00 2001 From: Matt Corallo Date: Mon, 19 Apr 2021 17:17:41 -0400 Subject: [PATCH] Support FromStr and Display impls, even if impl'd in a priv module --- c-bindings-gen/src/main.rs | 61 ++++++++++++++++++++++++- c-bindings-gen/src/types.rs | 7 +++ lightning-c-bindings/src/c_types/mod.rs | 25 ++++++++-- 3 files changed, 88 insertions(+), 5 deletions(-) diff --git a/c-bindings-gen/src/main.rs b/c-bindings-gen/src/main.rs index faa51f5..a38e6e3 100644 --- a/c-bindings-gen/src/main.rs +++ b/c-bindings-gen/src/main.rs @@ -33,6 +33,8 @@ mod blocks; use types::*; use blocks::*; +const DEFAULT_IMPORTS: &'static str = "\nuse std::str::FromStr;\nuse std::ffi::c_void;\nuse bitcoin::hashes::Hash;\nuse crate::c_types::*;\n"; + // ************************************* // *** Manually-expanded conversions *** // ************************************* @@ -957,6 +959,30 @@ fn writeln_impl(w: &mut W, i: &syn::ItemImpl, types: &mut Typ writeln!(w, "pub extern \"C\" fn {}_clone(orig: &{}) -> {} {{", ident, ident, ident).unwrap(); writeln!(w, "\torig.clone()").unwrap(); writeln!(w, "}}").unwrap(); + } else if path_matches_nongeneric(&trait_path.1, &["FromStr"]) { + if let Some(container) = types.get_c_mangled_container_type( + vec![&*i.self_ty, &syn::Type::Tuple(syn::TypeTuple { paren_token: Default::default(), elems: syn::punctuated::Punctuated::new() })], + Some(&gen_types), "Result") { + writeln!(w, "#[no_mangle]").unwrap(); + writeln!(w, "/// Read a {} object from a string", ident).unwrap(); + writeln!(w, "pub extern \"C\" fn {}_from_str(s: crate::c_types::Str) -> {} {{", ident, container).unwrap(); + writeln!(w, "\tmatch {}::from_str(s.into()) {{", resolved_path).unwrap(); + writeln!(w, "\t\tOk(r) => {{").unwrap(); + let new_var = types.write_to_c_conversion_new_var(w, &syn::Ident::new("r", Span::call_site()), &*i.self_ty, Some(&gen_types), false); + write!(w, "\t\t\tcrate::c_types::CResultTempl::ok(\n\t\t\t\t").unwrap(); + types.write_to_c_conversion_inline_prefix(w, &*i.self_ty, Some(&gen_types), false); + write!(w, "{}r", if new_var { "local_" } else { "" }).unwrap(); + types.write_to_c_conversion_inline_suffix(w, &*i.self_ty, Some(&gen_types), false); + writeln!(w, "\n\t\t\t)\n\t\t}},").unwrap(); + writeln!(w, "\t\tErr(e) => crate::c_types::CResultTempl::err(0u8),").unwrap(); + writeln!(w, "\t}}.into()\n}}").unwrap(); + } + } else if path_matches_nongeneric(&trait_path.1, &["Display"]) { + writeln!(w, "#[no_mangle]").unwrap(); + writeln!(w, "/// Get the string representation of a {} object", ident).unwrap(); + writeln!(w, "pub extern \"C\" fn {}_to_str(o: &{}) -> Str {{", ident, resolved_path).unwrap(); + writeln!(w, "\tformat!(\"{{}}\", o).into()").unwrap(); + writeln!(w, "}}").unwrap(); } else { //XXX: implement for other things like ToString // If we have no generics, try a manual implementation: @@ -1289,6 +1315,35 @@ fn writeln_fn<'a, 'b, W: std::io::Write>(w: &mut W, f: &'a syn::ItemFn, types: & // *** File/Crate Walking Logic *** // ******************************** +fn convert_priv_mod<'a, 'b: 'a, W: std::io::Write>(w: &mut W, libast: &'b FullLibraryAST, crate_types: &CrateTypes<'b>, out_dir: &str, mod_path: &str, module: &'b syn::ItemMod) { + // We want to ignore all items declared in this module (as they are not pub), but we still need + // to give the ImportResolver any use statements, so we copy them here. + let mut use_items = Vec::new(); + for item in module.content.as_ref().unwrap().1.iter() { + if let syn::Item::Use(_) = item { + use_items.push(item); + } + } + let import_resolver = ImportResolver::from_borrowed_items(mod_path.splitn(2, "::").next().unwrap(), &libast.dependencies, mod_path, &use_items); + let mut types = TypeResolver::new(mod_path, import_resolver, crate_types); + + writeln!(w, "mod {} {{\n{}", module.ident, DEFAULT_IMPORTS).unwrap(); + for item in module.content.as_ref().unwrap().1.iter() { + match item { + syn::Item::Mod(m) => convert_priv_mod(w, libast, crate_types, out_dir, &format!("{}::{}", mod_path, module.ident), m), + syn::Item::Impl(i) => { + if let &syn::Type::Path(ref p) = &*i.self_ty { + if p.path.get_ident().is_some() { + writeln_impl(w, i, &mut types); + } + } + }, + _ => {}, + } + } + writeln!(w, "}}").unwrap(); +} + /// 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. @@ -1337,7 +1392,7 @@ fn convert_file<'a, 'b>(libast: &'a FullLibraryAST, crate_types: &CrateTypes<'a> writeln!(out, "pub mod c_types;").unwrap(); writeln!(out, "pub mod bitcoin;").unwrap(); } else { - writeln!(out, "\nuse std::ffi::c_void;\nuse bitcoin::hashes::Hash;\nuse crate::c_types::*;\n").unwrap(); + writeln!(out, "{}", DEFAULT_IMPORTS).unwrap(); } for m in submods { @@ -1371,7 +1426,9 @@ fn convert_file<'a, 'b>(libast: &'a FullLibraryAST, crate_types: &CrateTypes<'a> writeln_trait(&mut out, &t, &mut type_resolver, header_file, cpp_header_file); } }, - syn::Item::Mod(_) => {}, // We don't have to do anything - the top loop handles these. + syn::Item::Mod(m) => { + convert_priv_mod(&mut out, libast, crate_types, out_dir, &format!("{}::{}", module, m.ident), m); + }, syn::Item::Const(c) => { // Re-export any primitive-type constants. if let syn::Visibility::Public(_) = c.vis { diff --git a/c-bindings-gen/src/types.rs b/c-bindings-gen/src/types.rs index e4f37c6..f8ecc7c 100644 --- a/c-bindings-gen/src/types.rs +++ b/c-bindings-gen/src/types.rs @@ -2351,6 +2351,13 @@ impl<'a, 'c: 'a> TypeResolver<'a, 'c> { } self.write_c_mangled_container_path_intern(w, args, generics, ident, is_ref, is_mut, ptr_for_ref, false) } + pub fn get_c_mangled_container_type(&self, args: Vec<&syn::Type>, generics: Option<&GenericTypes>, template_name: &str) -> Option { + let mut out = Vec::new(); + if !self.write_c_mangled_container_path(&mut out, args, generics, template_name, false, false, false) { + return None; + } + Some(String::from_utf8(out).unwrap()) + } // ********************************** // *** C Type Equivalent Printing *** diff --git a/lightning-c-bindings/src/c_types/mod.rs b/lightning-c-bindings/src/c_types/mod.rs index 2248ec2..cd96dff 100644 --- a/lightning-c-bindings/src/c_types/mod.rs +++ b/lightning-c-bindings/src/c_types/mod.rs @@ -338,18 +338,20 @@ pub(crate) fn deserialize_obj_arg>(s } #[repr(C)] -#[derive(Copy, Clone)] +#[derive(Clone)] /// A Rust str object, ie a reference to a UTF8-valid string. /// This is *not* null-terminated so cannot be used directly as a C string! pub struct Str { /// A pointer to the string's bytes, in UTF8 encoding pub chars: *const u8, /// The number of bytes (not characters!) pointed to by `chars` - pub len: usize + pub len: usize, + /// Whether the data pointed to by `chars` should be freed or not. + pub chars_is_owned: bool, } impl Into for &'static str { fn into(self) -> Str { - Str { chars: self.as_ptr(), len: self.len() } + Str { chars: self.as_ptr(), len: self.len(), chars_is_owned: false } } } impl Into<&'static str> for Str { @@ -358,6 +360,23 @@ impl Into<&'static str> for Str { std::str::from_utf8(unsafe { std::slice::from_raw_parts(self.chars, self.len) }).unwrap() } } +impl Into for String { + fn into(self) -> Str { + let s = Box::leak(self.into_boxed_str()); + Str { chars: s.as_ptr(), len: s.len(), chars_is_owned: true } + } +} + +impl Drop for Str { + fn drop(&mut self) { + if self.chars_is_owned && self.len != 0 { + let _ = derived::CVec_u8Z { data: self.chars as *mut u8, datalen: self.len }; + } + } +} +#[no_mangle] +/// Frees the data buffer, if chars_is_owned is set and len > 0. +pub extern "C" fn Str_free(_res: Str) { } // Note that the C++ headers memset(0) all the Templ types to avoid deallocation! // Thus, they must gracefully handle being completely null in _free. -- 2.39.5