From: Matt Corallo Date: Fri, 29 Dec 2023 20:50:22 +0000 (+0000) Subject: Support passing lifetime'd enums to C X-Git-Tag: v0.0.121.0^2~12 X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=commitdiff_plain;h=349213afe7baff6bce98dce44c5970519a5efbdb;p=ldk-c-bindings Support passing lifetime'd enums to C While this is generally unsafe, we have to do something for `CandidateRouteHop`, which is passed to the scorer. Because its incredibly performance-sensitive, forcing the bindings users to take a performance hit just to make the scoring interface marginally safer seems like a bad trade-off. --- diff --git a/c-bindings-gen/src/blocks.rs b/c-bindings-gen/src/blocks.rs index e419fe0..664ca44 100644 --- a/c-bindings-gen/src/blocks.rs +++ b/c-bindings-gen/src/blocks.rs @@ -748,6 +748,14 @@ pub fn write_method_call_params(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: &mut W, generics: &syn::Generics, generics_impld: &syn::PathArguments, types: &TypeResolver, concrete_lifetimes: bool) { + maybe_write_generics_intern(w, generics, generics_impld, types, concrete_lifetimes, false); +} + +pub fn maybe_write_non_lifetime_generics(w: &mut W, generics: &syn::Generics, generics_impld: &syn::PathArguments, types: &TypeResolver) { + maybe_write_generics_intern(w, generics, generics_impld, types, false, true); +} + +fn maybe_write_generics_intern(w: &mut W, generics: &syn::Generics, generics_impld: &syn::PathArguments, types: &TypeResolver, concrete_lifetimes: bool, dummy_lifetimes: bool) { let mut gen_types = GenericTypes::new(None); assert!(gen_types.learn_generics(generics, types)); if generics.params.is_empty() { return; } @@ -789,7 +797,9 @@ pub fn maybe_write_generics(w: &mut W, generics: &syn::Generi } }, syn::GenericParam::Lifetime(lt) => { - if concrete_lifetimes { + if dummy_lifetimes { + write!(w, "'_").unwrap(); + } else if concrete_lifetimes { write!(w, "'static").unwrap(); } else { write!(w, "{}'{}", if idx != 0 { ", " } else { "" }, lt.lifetime.ident).unwrap(); diff --git a/c-bindings-gen/src/main.rs b/c-bindings-gen/src/main.rs index 7d6a452..b72adca 100644 --- a/c-bindings-gen/src/main.rs +++ b/c-bindings-gen/src/main.rs @@ -1809,7 +1809,11 @@ fn writeln_enum<'a, 'b, W: std::io::Write>(w: &mut W, e: &'a syn::ItemEnum, type macro_rules! write_conv { ($fn_sig: expr, $to_c: expr, $ref: expr) => { - writeln!(w, "\t#[allow(unused)]\n\tpub(crate) fn {} {{\n\t\tmatch {} {{", $fn_sig, if $to_c { "native" } else { "self" }).unwrap(); + writeln!(w, "\t#[allow(unused)]\n\tpub(crate) fn {} {{", $fn_sig).unwrap(); + if $to_c && $ref { + writeln!(w, "\t\tlet native = unsafe {{ &*(native as *const _ as *const c_void as *const native{}) }};", e.ident).unwrap(); + } + writeln!(w, "\t\tmatch {} {{", if $to_c { "native" } else { "self" }).unwrap(); for var in e.variants.iter() { write!(w, "\t\t\t{}{}::{} ", if $to_c { "native" } else { "" }, e.ident, var.ident).unwrap(); let mut empty_tuple_variant = false; @@ -1933,7 +1937,10 @@ fn writeln_enum<'a, 'b, W: std::io::Write>(w: &mut W, e: &'a syn::ItemEnum, type } write_conv!(format!("into_native(self) -> native{}", e.ident), false, false); if is_clonable { - write_conv!(format!("from_native(native: &native{}) -> Self", e.ident), true, true); + let mut args = Vec::new(); + maybe_write_non_lifetime_generics(&mut args, &e.generics, &syn::PathArguments::None, &types); + let fn_line = format!("from_native(native: &{}Import{}) -> Self", e.ident, String::from_utf8(args).unwrap()); + write_conv!(fn_line, true, true); } write_conv!(format!("native_into(native: native{}) -> Self", e.ident), true, false); writeln!(w, "}}").unwrap();