Support converting Option<&[]> to C

[ldk-c-bindings] / c-bindings-gen / src / types.rs

diff --git a/c-bindings-gen/src/types.rs b/c-bindings-gen/src/types.rs
index 224b3ecfcb8caa3905ce45823aaf27abf7b3ff2f..14fd918e2be81cb267a01f08f18206bf0bbd1b7b 100644 (file)
--- a/c-bindings-gen/src/types.rs
+++ b/c-bindings-gen/src/types.rs
@@ -46,6 +46,10 @@ pub fn get_single_remaining_path_seg<'a, I: Iterator<Item=&'a syn::PathSegment>>
        } else { None }
 }
 
+pub fn first_seg_is_stdlib(first_seg_str: &str) -> bool {
+       first_seg_str == "std" || first_seg_str == "core" || first_seg_str == "alloc"
+}
+
 pub fn single_ident_generic_path_to_ident(p: &syn::Path) -> Option<&syn::Ident> {
        if p.segments.len() == 1 {
                Some(&p.segments.iter().next().unwrap().ident)
@@ -600,7 +604,7 @@ impl<'mod_lifetime, 'crate_lft: 'mod_lifetime> ImportResolver<'mod_lifetime, 'cr
                                }
                        } else if let Some(_) = self.priv_modules.get(&first_seg.ident) {
                                Some(format!("{}::{}{}", self.module_path, first_seg.ident, remaining))
-                       } else if first_seg_str == "std" || first_seg_str == "core" || self.dependencies.contains(&first_seg.ident) {
+                       } else if first_seg_is_stdlib(&first_seg_str) || self.dependencies.contains(&first_seg.ident) {
                                Some(first_seg_str + &remaining)
                        } else { None }
                }
@@ -1369,6 +1373,14 @@ impl<'a, 'c: 'a> TypeResolver<'a, 'c> {
                                        }
                                }
                                if let Some(t) = single_contained {
+                                       if let syn::Type::Reference(syn::TypeReference { elem, .. }) = t {
+                                               if let syn::Type::Slice(_) = &**elem {
+                                                       return Some(("if ", vec![
+                                                                       (".is_none() { SmartPtr::null() } else { SmartPtr::from_obj(".to_string(),
+                                                                        format!("({}.unwrap())", var_access))
+                                                               ], ") }", ContainerPrefixLocation::PerConv));
+                                               }
+                                       }
                                        let mut v = Vec::new();
                                        self.write_empty_rust_val(generics, &mut v, t);
                                        let s = String::from_utf8(v).unwrap();
@@ -2102,7 +2114,8 @@ impl<'a, 'c: 'a> TypeResolver<'a, 'c> {
 
                                if let Some((prefix, conversions, suffix, prefix_location)) = container_lookup(&$container_type, is_ref && ty_has_inner, only_contained_type, ident, var) {
                                        assert_eq!(conversions.len(), $args_len);
-                                       write!(w, "let mut local_{}{} = ", ident, if !to_c && needs_ref_map {"_base"} else { "" }).unwrap();
+                                       write!(w, "let mut local_{}{} = ", ident,
+                                               if (!to_c && needs_ref_map) || (to_c && $container_type == "Option" && contains_slice) {"_base"} else { "" }).unwrap();
                                        if prefix_location == ContainerPrefixLocation::OutsideConv {
                                                var_prefix(w, $args_iter().next().unwrap(), generics, is_ref, ptr_for_ref, true);
                                        }
@@ -2127,7 +2140,7 @@ impl<'a, 'c: 'a> TypeResolver<'a, 'c> {
                                                        write!(w, "ObjOps::heap_alloc(").unwrap();
                                                }
 
-                                               write!(w, "{}{}", if contains_slice { "local_" } else { "" }, if new_var { new_var_name } else { var_access }).unwrap();
+                                               write!(w, "{}{}", if contains_slice && !to_c { "local_" } else { "" }, if new_var { new_var_name } else { var_access }).unwrap();
                                                if prefix_location == ContainerPrefixLocation::PerConv {
                                                        var_suffix(w, conv_ty, generics, is_ref && ty_has_inner, ptr_for_ref, false);
                                                } else if !is_ref && !needs_ref_map && to_c && only_contained_has_inner {
@@ -2146,6 +2159,8 @@ impl<'a, 'c: 'a> TypeResolver<'a, 'c> {
                                                        write!(w, ".map(|a| &a[..])").unwrap();
                                                }
                                                write!(w, ";").unwrap();
+                                       } else if to_c && $container_type == "Option" && contains_slice {
+                                               write!(w, " let mut local_{} = *local_{}_base;", ident, ident).unwrap();
                                        }
                                        return true;
                                }