Merge pull request #51 from TheBlueMatt/main
[ldk-c-bindings] / c-bindings-gen / src / blocks.rs
index 88172722efbda088aef61443fba43e2af6515e07..b2f952be5fa1cb3fdcb6f51a6d677d7680f59d60 100644 (file)
@@ -20,7 +20,7 @@ use crate::types::*;
 /// Writes out a C++ wrapper class for the given type, which contains various utilities to access
 /// the underlying C-mapped type safely avoiding some common memory management issues by handling
 /// resource-freeing and prevending accidental raw copies.
-pub fn write_cpp_wrapper(cpp_header_file: &mut File, ty: &str, has_destructor: bool) {
+pub fn write_cpp_wrapper(cpp_header_file: &mut File, ty: &str, has_destructor: bool, trait_methods: Option<Vec<(String, String)>>) {
        writeln!(cpp_header_file, "class {} {{", ty).unwrap();
        writeln!(cpp_header_file, "private:").unwrap();
        writeln!(cpp_header_file, "\tLDK{} self;", ty).unwrap();
@@ -39,6 +39,14 @@ pub fn write_cpp_wrapper(cpp_header_file: &mut File, ty: &str, has_destructor: b
        writeln!(cpp_header_file, "\tLDK{}* operator ->() {{ return &self; }}", ty).unwrap();
        writeln!(cpp_header_file, "\tconst LDK{}* operator &() const {{ return &self; }}", ty).unwrap();
        writeln!(cpp_header_file, "\tconst LDK{}* operator ->() const {{ return &self; }}", ty).unwrap();
+       if let Some(methods) = trait_methods {
+               for (meth_name, meth_docs) in methods {
+                       cpp_header_file.write_all(meth_docs.as_bytes()).unwrap();
+                       // Note that we have zero logic to print C/C__ code for a given function. Instead, we
+                       // simply use sed to replace the following in genbindings.sh
+                       writeln!(cpp_header_file, "XXX {} {}", ty, meth_name).unwrap();
+               }
+       }
        writeln!(cpp_header_file, "}};").unwrap();
 }
 
@@ -116,6 +124,12 @@ pub fn write_result_block<W: std::io::Write>(w: &mut W, mangled_container: &str,
        writeln!(w, "\t}}").unwrap();
        writeln!(w, "}}").unwrap();
 
+       writeln!(w, "/// Checks if the given object is currently in the success state").unwrap();
+       writeln!(w, "#[no_mangle]").unwrap();
+       writeln!(w, "pub extern \"C\" fn {}_is_ok(o: &{}) -> bool {{", mangled_container, mangled_container).unwrap();
+       writeln!(w, "\to.result_ok").unwrap();
+       writeln!(w, "}}").unwrap();
+
        writeln!(w, "#[no_mangle]").unwrap();
        writeln!(w, "/// Frees any resources used by the {}.", mangled_container).unwrap();
        writeln!(w, "pub extern \"C\" fn {}_free(_res: {}) {{ }}", mangled_container, mangled_container).unwrap();
@@ -137,12 +151,8 @@ pub fn write_result_block<W: std::io::Write>(w: &mut W, mangled_container: &str,
        writeln!(w, "\t}}").unwrap();
        writeln!(w, "}}").unwrap();
 
-       // TODO: Templates should use () now that they can, too
-       let templ_ok_type = if ok_type != "()" { ok_type } else { "u8" };
-       let templ_err_type = if err_type != "()" { err_type } else { "u8" };
-
-       writeln!(w, "impl From<crate::c_types::CResultTempl<{}, {}>> for {} {{", templ_ok_type, templ_err_type, mangled_container).unwrap();
-       writeln!(w, "\tfn from(mut o: crate::c_types::CResultTempl<{}, {}>) -> Self {{", templ_ok_type, templ_err_type).unwrap();
+       writeln!(w, "impl From<crate::c_types::CResultTempl<{}, {}>> for {} {{", ok_type, err_type, mangled_container).unwrap();
+       writeln!(w, "\tfn from(mut o: crate::c_types::CResultTempl<{}, {}>) -> Self {{", ok_type, err_type).unwrap();
        writeln!(w, "\t\tlet contents = if o.result_ok {{").unwrap();
        if ok_type != "()" {
                writeln!(w, "\t\t\tlet result = unsafe {{ o.contents.result }};").unwrap();
@@ -196,7 +206,7 @@ pub fn write_result_block<W: std::io::Write>(w: &mut W, mangled_container: &str,
                writeln!(w, "#[no_mangle]").unwrap();
                writeln!(w, "/// Creates a new {} which has the same data as `orig`", mangled_container).unwrap();
                writeln!(w, "/// but with all dynamically-allocated buffers duplicated in new buffers.").unwrap();
-               writeln!(w, "pub extern \"C\" fn {}_clone(orig: &{}) -> {} {{ orig.clone() }}", mangled_container, mangled_container, mangled_container).unwrap();
+               writeln!(w, "pub extern \"C\" fn {}_clone(orig: &{}) -> {} {{ Clone::clone(&orig) }}", mangled_container, mangled_container, mangled_container).unwrap();
        }
 }
 
@@ -297,7 +307,7 @@ pub fn write_tuple_block<W: std::io::Write>(w: &mut W, mangled_container: &str,
                writeln!(w, "\tfn clone(&self) -> Self {{").unwrap();
                writeln!(w, "\t\tSelf {{").unwrap();
                for idx in 0..types.len() {
-                       writeln!(w, "\t\t\t{}: self.{}.clone(),", ('a' as u8 + idx as u8) as char, ('a' as u8 + idx as u8) as char).unwrap();
+                       writeln!(w, "\t\t\t{}: Clone::clone(&self.{}),", ('a' as u8 + idx as u8) as char, ('a' as u8 + idx as u8) as char).unwrap();
                }
                writeln!(w, "\t\t}}").unwrap();
                writeln!(w, "\t}}").unwrap();
@@ -305,7 +315,7 @@ pub fn write_tuple_block<W: std::io::Write>(w: &mut W, mangled_container: &str,
                writeln!(w, "#[no_mangle]").unwrap();
                writeln!(w, "/// Creates a new tuple which has the same data as `orig`").unwrap();
                writeln!(w, "/// but with all dynamically-allocated buffers duplicated in new buffers.").unwrap();
-               writeln!(w, "pub extern \"C\" fn {}_clone(orig: &{}) -> {} {{ orig.clone() }}", mangled_container, mangled_container, mangled_container).unwrap();
+               writeln!(w, "pub extern \"C\" fn {}_clone(orig: &{}) -> {} {{ Clone::clone(&orig) }}", mangled_container, mangled_container, mangled_container).unwrap();
        }
 
        writeln!(w, "/// Creates a new {} from the contained elements.", mangled_container).unwrap();
@@ -336,24 +346,38 @@ pub fn write_option_block<W: std::io::Write>(w: &mut W, mangled_container: &str,
        writeln!(w, "/// An enum which can either contain a {} or not", inner_type).unwrap();
        writeln!(w, "pub enum {} {{", mangled_container).unwrap();
        writeln!(w, "\t/// When we're in this state, this {} contains a {}", mangled_container, inner_type).unwrap();
-       writeln!(w, "\tSome({}),", inner_type).unwrap();
+       if inner_type != "" {
+               writeln!(w, "\tSome({}),", inner_type).unwrap();
+       } else {
+               writeln!(w, "\tSome,").unwrap();
+       }
        writeln!(w, "\t/// When we're in this state, this {} contains nothing", mangled_container).unwrap();
        writeln!(w, "\tNone").unwrap();
        writeln!(w, "}}").unwrap();
 
        writeln!(w, "impl {} {{", mangled_container).unwrap();
        writeln!(w, "\t#[allow(unused)] pub(crate) fn is_some(&self) -> bool {{").unwrap();
-       writeln!(w, "\t\tif let Self::Some(_) = self {{ true }} else {{ false }}").unwrap();
+       writeln!(w, "\t\tif let Self::None = self {{ false }} else {{ true }}").unwrap();
        writeln!(w, "\t}}").unwrap();
-       writeln!(w, "\t#[allow(unused)] pub(crate) fn take(mut self) -> {} {{", inner_type).unwrap();
-       writeln!(w, "\t\tif let Self::Some(v) = self {{ v }} else {{ unreachable!() }}").unwrap();
+       writeln!(w, "\t#[allow(unused)] pub(crate) fn is_none(&self) -> bool {{").unwrap();
+       writeln!(w, "\t\t!self.is_some()").unwrap();
        writeln!(w, "\t}}").unwrap();
+       if inner_type != "" {
+               writeln!(w, "\t#[allow(unused)] pub(crate) fn take(mut self) -> {} {{", inner_type).unwrap();
+               writeln!(w, "\t\tif let Self::Some(v) = self {{ v }} else {{ unreachable!() }}").unwrap();
+               writeln!(w, "\t}}").unwrap();
+       }
        writeln!(w, "}}").unwrap();
 
        writeln!(w, "#[no_mangle]").unwrap();
        writeln!(w, "/// Constructs a new {} containing a {}", mangled_container, inner_type).unwrap();
-       writeln!(w, "pub extern \"C\" fn {}_some(o: {}) -> {} {{", mangled_container, inner_type, mangled_container).unwrap();
-       writeln!(w, "\t{}::Some(o)", mangled_container).unwrap();
+       if inner_type != "" {
+               writeln!(w, "pub extern \"C\" fn {}_some(o: {}) -> {} {{", mangled_container, inner_type, mangled_container).unwrap();
+               writeln!(w, "\t{}::Some(o)", mangled_container).unwrap();
+       } else {
+               writeln!(w, "pub extern \"C\" fn {}_some() -> {} {{", mangled_container, mangled_container).unwrap();
+               writeln!(w, "\t{}::Some", mangled_container).unwrap();
+       }
        writeln!(w, "}}").unwrap();
 
        writeln!(w, "#[no_mangle]").unwrap();
@@ -369,12 +393,38 @@ pub fn write_option_block<W: std::io::Write>(w: &mut W, mangled_container: &str,
                writeln!(w, "#[no_mangle]").unwrap();
                writeln!(w, "/// Creates a new {} which has the same data as `orig`", mangled_container).unwrap();
                writeln!(w, "/// but with all dynamically-allocated buffers duplicated in new buffers.").unwrap();
-               writeln!(w, "pub extern \"C\" fn {}_clone(orig: &{}) -> {} {{ orig.clone() }}", mangled_container, mangled_container, mangled_container).unwrap();
+               writeln!(w, "pub extern \"C\" fn {}_clone(orig: &{}) -> {} {{ Clone::clone(&orig) }}", mangled_container, mangled_container, mangled_container).unwrap();
        }
 }
 
+/// Prints the docs from a given attribute list unless its tagged no export
+pub fn writeln_fn_docs<'a, W: std::io::Write, I>(w: &mut W, attrs: &[syn::Attribute], prefix: &str, types: &mut TypeResolver, generics: Option<&GenericTypes>, args: I, ret: &syn::ReturnType) where I: Iterator<Item = &'a syn::FnArg> {
+       writeln_docs_impl(w, attrs, prefix, Some((types, generics,
+               args.filter_map(|arg| if let syn::FnArg::Typed(ty) = arg {
+                               if let syn::Pat::Ident(id) = &*ty.pat {
+                                       Some((id.ident.to_string(), &*ty.ty))
+                               } else { unimplemented!() }
+                       } else { None }),
+               if let syn::ReturnType::Type(_, ty) = ret { Some(&**ty) } else { None },
+               None
+       )));
+}
+
 /// Prints the docs from a given attribute list unless its tagged no export
 pub fn writeln_docs<W: std::io::Write>(w: &mut W, attrs: &[syn::Attribute], prefix: &str) {
+       writeln_docs_impl(w, attrs, prefix, None::<(_, _, std::vec::Drain<'_, (String, &syn::Type)>, _, _)>);
+}
+
+pub fn writeln_arg_docs<'a, W: std::io::Write, I>(w: &mut W, attrs: &[syn::Attribute], prefix: &str, types: &mut TypeResolver, generics: Option<&GenericTypes>, args: I, ret: Option<&syn::Type>) where I: Iterator<Item = (String, &'a syn::Type)> {
+       writeln_docs_impl(w, attrs, prefix, Some((types, generics, args, ret, None)))
+}
+
+pub fn writeln_field_docs<W: std::io::Write>(w: &mut W, attrs: &[syn::Attribute], prefix: &str, types: &mut TypeResolver, generics: Option<&GenericTypes>, field: &syn::Type) {
+       writeln_docs_impl(w, attrs, prefix, Some((types, generics, vec![].drain(..), None, Some(field))))
+}
+
+/// Prints the docs from a given attribute list unless its tagged no export
+fn writeln_docs_impl<'a, W: std::io::Write, I>(w: &mut W, attrs: &[syn::Attribute], prefix: &str, method_args_ret: Option<(&mut TypeResolver, Option<&GenericTypes>, I, Option<&syn::Type>, Option<&syn::Type>)>) where I: Iterator<Item = (String, &'a syn::Type)> {
        for attr in attrs.iter() {
                let tokens_clone = attr.tokens.clone();
                let mut token_iter = tokens_clone.into_iter();
@@ -410,6 +460,51 @@ pub fn writeln_docs<W: std::io::Write>(w: &mut W, attrs: &[syn::Attribute], pref
                        },
                }
        }
+       if let Some((types, generics, inp, outp, field)) = method_args_ret {
+               let mut nullable_found = false;
+               for (name, inp) in inp {
+                       if types.skip_arg(inp, generics) { continue; }
+                       if if let syn::Type::Reference(syn::TypeReference { elem, .. }) = inp {
+                               if let syn::Type::Path(syn::TypePath { ref path, .. }) = &**elem {
+                                       types.is_path_transparent_container(path, generics, true)
+                               } else { false }
+                       } else if let syn::Type::Path(syn::TypePath { ref path, .. }) = inp {
+                               types.is_path_transparent_container(path, generics, true)
+                       } else { false } {
+                               // Note downstream clients match this text exactly so any changes may require
+                               // changes in the Java and Swift bindings, at least.
+                               if !nullable_found { writeln!(w, "{}///", prefix).unwrap(); }
+                               nullable_found = true;
+                               writeln!(w, "{}/// Note that {} (or a relevant inner pointer) may be NULL or all-0s to represent None", prefix, name).unwrap();
+                       }
+               }
+               if if let Some(syn::Type::Reference(syn::TypeReference { elem, .. })) = outp {
+                       if let syn::Type::Path(syn::TypePath { ref path, .. }) = &**elem {
+                               types.is_path_transparent_container(path, generics, true)
+                       } else { false }
+               } else if let Some(syn::Type::Path(syn::TypePath { ref path, .. })) = outp {
+                       types.is_path_transparent_container(path, generics, true)
+               } else { false } {
+                       // Note downstream clients match this text exactly so any changes may require
+                       // changes in the Java and Swift bindings, at least.
+                       if !nullable_found { writeln!(w, "{}///", prefix).unwrap(); }
+                       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();
+               }
+               if if let Some(syn::Type::Reference(syn::TypeReference { elem, .. })) = field {
+                       if let syn::Type::Path(syn::TypePath { ref path, .. }) = &**elem {
+                               types.is_path_transparent_container(path, generics, true)
+                       } else { false }
+               } else if let Some(syn::Type::Path(syn::TypePath { ref path, .. })) = field {
+                       types.is_path_transparent_container(path, generics, true)
+               } else { false } {
+                       // Note downstream clients match this text exactly so any changes may require
+                       // changes in the Java and Swift bindings, at least.
+                       if !nullable_found { writeln!(w, "{}///", prefix).unwrap(); }
+                       writeln!(w, "{}/// Note that this (or a relevant inner pointer) may be NULL or all-0s to represent None", prefix).unwrap();
+               }
+       }
+
 }
 
 /// Print the parameters in a method declaration, starting after the open parenthesis, through and
@@ -622,7 +717,7 @@ pub fn write_method_call_params<W: std::io::Write>(w: &mut W, sig: &syn::Signatu
                                write!(w, "ret").unwrap();
                        } else if !to_c && self_segs_iter.is_some() && self_segs_iter.unwrap().next().is_none() {
                                // If we're returning "Self" (and not "Self::X"), just do it manually
-                               write!(w, "{} {{ inner: Box::into_raw(Box::new(ret)), is_owned: true }}", this_type).unwrap();
+                               write!(w, "{} {{ inner: ObjOps::heap_alloc(ret), is_owned: true }}", this_type).unwrap();
                        } else if to_c {
                                let new_var = types.write_from_c_conversion_new_var(w, &format_ident!("ret"), rtype, generics);
                                if new_var {
@@ -655,17 +750,9 @@ pub fn maybe_write_generics<W: std::io::Write>(w: &mut W, generics: &syn::Generi
                for (idx, generic) in generics.params.iter().enumerate() {
                        match generic {
                                syn::GenericParam::Type(type_param) => {
-                                       let mut printed_param = false;
-                                       for bound in type_param.bounds.iter() {
-                                               if let syn::TypeParamBound::Trait(trait_bound) = bound {
-                                                       assert_simple_bound(&trait_bound);
-                                                       write!(w, "{}{}", if idx != 0 { ", " } else { "" }, gen_types.maybe_resolve_ident(&type_param.ident).unwrap()).unwrap();
-                                                       if printed_param {
-                                                               unimplemented!("Can't print generic params that have multiple non-lifetime bounds");
-                                                       }
-                                                       printed_param = true;
-                                               }
-                                       }
+                                       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);
                                },
                                syn::GenericParam::Lifetime(lt) => {
                                        if concrete_lifetimes {
@@ -681,4 +768,20 @@ pub fn maybe_write_generics<W: std::io::Write>(w: &mut W, generics: &syn::Generi
        }
 }
 
-
+pub fn maybe_write_lifetime_generics<W: std::io::Write>(w: &mut W, generics: &syn::Generics, types: &TypeResolver) {
+       let mut gen_types = GenericTypes::new(None);
+       assert!(gen_types.learn_generics(generics, types));
+       if generics.params.iter().any(|param| if let syn::GenericParam::Lifetime(_) = param { true } else { false }) {
+               write!(w, "<").unwrap();
+               for (idx, generic) in generics.params.iter().enumerate() {
+                       match generic {
+                               syn::GenericParam::Type(_) => {},
+                               syn::GenericParam::Lifetime(lt) => {
+                                       write!(w, "{}'{}", if idx != 0 { ", " } else { "" }, lt.lifetime.ident).unwrap();
+                               },
+                               _ => unimplemented!(),
+                       }
+               }
+               write!(w, ">").unwrap();
+       }
+}