Merge pull request #38 from TheBlueMatt/main
[ldk-c-bindings] / c-bindings-gen / src / blocks.rs
index 28323498336c750d97abe45e899d282a3042265a..9c404411a2719d4b979e8b920d1f0ef516e7b3c8 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();
 }
 
@@ -137,12 +145,8 @@ 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();
@@ -373,8 +377,34 @@ pub fn write_option_block<W: std::io::Write>(w: &mut W, mangled_container: &str,
        }
 }
 
+/// 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 +440,51 @@ 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
@@ -648,7 +723,7 @@ pub fn write_method_call_params<W: std::io::Write>(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: std::io::Write>(w: &mut W, generics: &syn::Generics, types: &TypeResolver, concrete_lifetimes: bool) {
-       let mut gen_types = GenericTypes::new();
+       let mut gen_types = GenericTypes::new(None);
        assert!(gen_types.learn_generics(generics, types));
        if !generics.params.is_empty() {
                write!(w, "<").unwrap();