Merge pull request #40 from TheBlueMatt/main
[ldk-c-bindings] / c-bindings-gen / src / main.rs
index cb7305bd7ee2356676326c30e8b699625d75b574..ce69294928af16714f3e7b645d34cbc2faa9f510 100644 (file)
@@ -563,7 +563,7 @@ fn writeln_opaque<W: std::io::Write>(w: &mut W, ident: &syn::Ident, struct_name:
        writeln!(w, "}}\n").unwrap();
        writeln!(w, "impl Drop for {} {{\n\tfn drop(&mut self) {{", struct_name).unwrap();
        writeln!(w, "\t\tif self.is_owned && !<*mut native{}>::is_null(self.inner) {{", ident).unwrap();
-       writeln!(w, "\t\t\tlet _ = unsafe {{ Box::from_raw(self.inner) }};\n\t\t}}\n\t}}\n}}").unwrap();
+       writeln!(w, "\t\t\tlet _ = unsafe {{ Box::from_raw(ObjOps::untweak_ptr(self.inner)) }};\n\t\t}}\n\t}}\n}}").unwrap();
        writeln!(w, "/// Frees any resources used by the {}, if is_owned is set and inner is non-NULL.", struct_name).unwrap();
        writeln!(w, "#[no_mangle]\npub extern \"C\" fn {}_free(this_obj: {}) {{ }}", struct_name, struct_name).unwrap();
        writeln!(w, "#[allow(unused)]").unwrap();
@@ -571,11 +571,17 @@ fn writeln_opaque<W: std::io::Write>(w: &mut W, ident: &syn::Ident, struct_name:
        writeln!(w, "extern \"C\" fn {}_free_void(this_ptr: *mut c_void) {{", struct_name).unwrap();
        writeln!(w, "\tunsafe {{ let _ = Box::from_raw(this_ptr as *mut native{}); }}\n}}", struct_name).unwrap();
        writeln!(w, "#[allow(unused)]").unwrap();
-       writeln!(w, "/// When moving out of the pointer, we have to ensure we aren't a reference, this makes that easy").unwrap();
        writeln!(w, "impl {} {{", struct_name).unwrap();
+       writeln!(w, "\tpub(crate) fn get_native_ref(&self) -> &'static native{} {{", struct_name).unwrap();
+       writeln!(w, "\t\tunsafe {{ &*ObjOps::untweak_ptr(self.inner) }}").unwrap();
+       writeln!(w, "\t}}").unwrap();
+       writeln!(w, "\tpub(crate) fn get_native_mut_ref(&self) -> &'static mut native{} {{", struct_name).unwrap();
+       writeln!(w, "\t\tunsafe {{ &mut *ObjOps::untweak_ptr(self.inner) }}").unwrap();
+       writeln!(w, "\t}}").unwrap();
+       writeln!(w, "\t/// When moving out of the pointer, we have to ensure we aren't a reference, this makes that easy").unwrap();
        writeln!(w, "\tpub(crate) fn take_inner(mut self) -> *mut native{} {{", struct_name).unwrap();
        writeln!(w, "\t\tassert!(self.is_owned);").unwrap();
-       writeln!(w, "\t\tlet ret = self.inner;").unwrap();
+       writeln!(w, "\t\tlet ret = ObjOps::untweak_ptr(self.inner);").unwrap();
        writeln!(w, "\t\tself.inner = std::ptr::null_mut();").unwrap();
        writeln!(w, "\t\tret").unwrap();
        writeln!(w, "\t}}\n}}").unwrap();
@@ -620,7 +626,7 @@ fn writeln_struct<'a, 'b, W: std::io::Write>(w: &mut W, s: &'a syn::ItemStruct,
                                                writeln_arg_docs(w, &field.attrs, "", types, Some(&gen_types), vec![].drain(..), Some(&ref_type));
                                                write!(w, "#[no_mangle]\npub extern \"C\" fn {}_get_{}(this_ptr: &{}) -> ", struct_name, ident, struct_name).unwrap();
                                                types.write_c_type(w, &ref_type, Some(&gen_types), true);
-                                               write!(w, " {{\n\tlet mut inner_val = &mut unsafe {{ &mut *this_ptr.inner }}.{};\n\t", ident).unwrap();
+                                               write!(w, " {{\n\tlet mut inner_val = &mut this_ptr.get_native_mut_ref().{};\n\t", ident).unwrap();
                                                let local_var = types.write_to_c_conversion_new_var(w, &format_ident!("inner_val"), &ref_type, Some(&gen_types), true);
                                                if local_var { write!(w, "\n\t").unwrap(); }
                                                types.write_to_c_conversion_inline_prefix(w, &ref_type, Some(&gen_types), true);
@@ -636,7 +642,7 @@ fn writeln_struct<'a, 'b, W: std::io::Write>(w: &mut W, s: &'a syn::ItemStruct,
                                                write!(w, ") {{\n\t").unwrap();
                                                let local_var = types.write_from_c_conversion_new_var(w, &format_ident!("val"), &field.ty, Some(&gen_types));
                                                if local_var { write!(w, "\n\t").unwrap(); }
-                                               write!(w, "unsafe {{ &mut *this_ptr.inner }}.{} = ", ident).unwrap();
+                                               write!(w, "unsafe {{ &mut *ObjOps::untweak_ptr(this_ptr.inner) }}.{} = ", ident).unwrap();
                                                types.write_from_c_conversion_prefix(w, &field.ty, Some(&gen_types));
                                                write!(w, "val").unwrap();
                                                types.write_from_c_conversion_suffix(w, &field.ty, Some(&gen_types));
@@ -662,7 +668,7 @@ fn writeln_struct<'a, 'b, W: std::io::Write>(w: &mut W, s: &'a syn::ItemStruct,
                                        write!(w, "\n\t").unwrap();
                                }
                        }
-                       writeln!(w, "{} {{ inner: Box::into_raw(Box::new(native{} {{", struct_name, s.ident).unwrap();
+                       writeln!(w, "{} {{ inner: ObjOps::heap_alloc(native{} {{", struct_name, s.ident).unwrap();
                        for field in fields.named.iter() {
                                write!(w, "\t\t{}: ", field.ident.as_ref().unwrap()).unwrap();
                                types.write_from_c_conversion_prefix(w, &field.ty, Some(&gen_types));
@@ -670,7 +676,7 @@ fn writeln_struct<'a, 'b, W: std::io::Write>(w: &mut W, s: &'a syn::ItemStruct,
                                types.write_from_c_conversion_suffix(w, &field.ty, Some(&gen_types));
                                writeln!(w, ",").unwrap();
                        }
-                       writeln!(w, "\t}})), is_owned: true }}\n}}").unwrap();
+                       writeln!(w, "\t}}), is_owned: true }}\n}}").unwrap();
                }
        }
 }
@@ -764,7 +770,7 @@ fn writeln_impl<W: std::io::Write>(w: &mut W, i: &syn::ItemImpl, types: &mut Typ
                                                // type-conversion logic without actually knowing the concrete native type.
                                                writeln!(w, "impl From<native{}> for crate::{} {{", ident, full_trait_path).unwrap();
                                                writeln!(w, "\tfn from(obj: native{}) -> Self {{", ident).unwrap();
-                                               writeln!(w, "\t\tlet mut rust_obj = {} {{ inner: Box::into_raw(Box::new(obj)), is_owned: true }};", ident).unwrap();
+                                               writeln!(w, "\t\tlet mut rust_obj = {} {{ inner: ObjOps::heap_alloc(obj), is_owned: true }};", ident).unwrap();
                                                writeln!(w, "\t\tlet mut ret = {}_as_{}(&rust_obj);", ident, trait_obj.ident).unwrap();
                                                writeln!(w, "\t\t// We want to free rust_obj when ret gets drop()'d, not rust_obj, so wipe rust_obj's pointer and set ret's free() fn").unwrap();
                                                writeln!(w, "\t\trust_obj.inner = std::ptr::null_mut();").unwrap();
@@ -775,7 +781,7 @@ fn writeln_impl<W: std::io::Write>(w: &mut W, i: &syn::ItemImpl, types: &mut Typ
                                                writeln!(w, "/// This copies the `inner` pointer in this_arg and thus the returned {} must be freed before this_arg is", trait_obj.ident).unwrap();
                                                write!(w, "#[no_mangle]\npub extern \"C\" fn {}_as_{}(this_arg: &{}) -> crate::{} {{\n", ident, trait_obj.ident, ident, full_trait_path).unwrap();
                                                writeln!(w, "\tcrate::{} {{", full_trait_path).unwrap();
-                                               writeln!(w, "\t\tthis_arg: unsafe {{ (*this_arg).inner as *mut c_void }},").unwrap();
+                                               writeln!(w, "\t\tthis_arg: unsafe {{ ObjOps::untweak_ptr((*this_arg).inner) as *mut c_void }},").unwrap();
                                                writeln!(w, "\t\tfree: None,").unwrap();
 
                                                macro_rules! write_meth {
@@ -826,7 +832,7 @@ fn writeln_impl<W: std::io::Write>(w: &mut W, i: &syn::ItemImpl, types: &mut Typ
                                                        (s, t) => {
                                                                if let Some(supertrait_obj) = types.crate_types.traits.get(s) {
                                                                        writeln!(w, "\t\t{}: crate::{} {{", t, s).unwrap();
-                                                                       writeln!(w, "\t\t\tthis_arg: unsafe {{ (*this_arg).inner as *mut c_void }},").unwrap();
+                                                                       writeln!(w, "\t\t\tthis_arg: unsafe {{ ObjOps::untweak_ptr((*this_arg).inner) as *mut c_void }},").unwrap();
                                                                        writeln!(w, "\t\t\tfree: None,").unwrap();
                                                                        for item in supertrait_obj.items.iter() {
                                                                                match item {
@@ -941,7 +947,7 @@ fn writeln_impl<W: std::io::Write>(w: &mut W, i: &syn::ItemImpl, types: &mut Typ
                                        } else if path_matches_nongeneric(&trait_path.1, &["Default"]) {
                                                writeln!(w, "/// Creates a \"default\" {}. See struct and individual field documentaiton for details on which values are used.", ident).unwrap();
                                                write!(w, "#[must_use]\n#[no_mangle]\npub extern \"C\" fn {}_default() -> {} {{\n", ident, ident).unwrap();
-                                               write!(w, "\t{} {{ inner: Box::into_raw(Box::new(Default::default())), is_owned: true }}\n", ident).unwrap();
+                                               write!(w, "\t{} {{ inner: ObjOps::heap_alloc(Default::default()), is_owned: true }}\n", ident).unwrap();
                                                write!(w, "}}\n").unwrap();
                                        } else if path_matches_nongeneric(&trait_path.1, &["core", "cmp", "PartialEq"]) {
                                        } else if path_matches_nongeneric(&trait_path.1, &["core", "cmp", "Eq"]) {
@@ -996,7 +1002,7 @@ fn writeln_impl<W: std::io::Write>(w: &mut W, i: &syn::ItemImpl, types: &mut Typ
                                                writeln!(w, "\tfn clone(&self) -> Self {{").unwrap();
                                                writeln!(w, "\t\tSelf {{").unwrap();
                                                writeln!(w, "\t\t\tinner: if <*mut native{}>::is_null(self.inner) {{ std::ptr::null_mut() }} else {{", ident).unwrap();
-                                               writeln!(w, "\t\t\t\tBox::into_raw(Box::new(unsafe {{ &*self.inner }}.clone())) }},").unwrap();
+                                               writeln!(w, "\t\t\t\tObjOps::heap_alloc(unsafe {{ &*ObjOps::untweak_ptr(self.inner) }}.clone()) }},").unwrap();
                                                writeln!(w, "\t\t\tis_owned: true,").unwrap();
                                                writeln!(w, "\t\t}}\n\t}}\n}}").unwrap();
                                                writeln!(w, "#[allow(unused)]").unwrap();
@@ -1093,9 +1099,9 @@ fn writeln_impl<W: std::io::Write>(w: &mut W, i: &syn::ItemImpl, types: &mut Typ
                                                                                                if takes_owned_self {
                                                                                                        write!(w, "(*unsafe {{ Box::from_raw(this_arg.take_inner()) }}).{}(", m.sig.ident).unwrap();
                                                                                                } else if takes_mut_self {
-                                                                                                       write!(w, "unsafe {{ &mut (*(this_arg.inner as *mut native{})) }}.{}(", ident, m.sig.ident).unwrap();
+                                                                                                       write!(w, "unsafe {{ &mut (*ObjOps::untweak_ptr(this_arg.inner as *mut native{})) }}.{}(", ident, m.sig.ident).unwrap();
                                                                                                } else {
-                                                                                                       write!(w, "unsafe {{ &*this_arg.inner }}.{}(", m.sig.ident).unwrap();
+                                                                                                       write!(w, "unsafe {{ &*ObjOps::untweak_ptr(this_arg.inner) }}.{}(", m.sig.ident).unwrap();
                                                                                                }
                                                                                        },
                                                                                        _ => unimplemented!(),
@@ -1170,6 +1176,23 @@ fn writeln_impl<W: std::io::Write>(w: &mut W, i: &syn::ItemImpl, types: &mut Typ
        }
 }
 
+/// Replaces upper case charachters with underscore followed by lower case except the first
+/// charachter and repeated upper case characthers (which are only made lower case).
+fn camel_to_snake_case(camel: &str) -> String {
+       let mut res = "".to_string();
+       let mut last_upper = -1;
+       for (idx, c) in camel.chars().enumerate() {
+               if c.is_uppercase() {
+                       if last_upper != idx as isize - 1 { res.push('_'); }
+                       res.push(c.to_lowercase().next().unwrap());
+                       last_upper = idx as isize;
+               } else {
+                       res.push(c);
+               }
+       }
+       res
+}
+
 
 /// Print a mapping of an enum. If all of the enum's fields are C-mapped in some form (or the enum
 /// is unitary), we generate an equivalent enum with all types replaced with their C mapped
@@ -1193,25 +1216,31 @@ fn writeln_enum<'a, 'b, W: std::io::Write>(w: &mut W, e: &'a syn::ItemEnum, type
        assert!(gen_types.learn_generics(&e.generics, types));
 
        let mut needs_free = false;
+       let mut constr = Vec::new();
 
        writeln!(w, "#[must_use]\n#[derive(Clone)]\n#[repr(C)]\npub enum {} {{", e.ident).unwrap();
        for var in e.variants.iter() {
                assert_eq!(export_status(&var.attrs), ExportStatus::Export); // We can't partially-export a mirrored enum
                writeln_docs(w, &var.attrs, "\t");
                write!(w, "\t{}", var.ident).unwrap();
+               writeln!(&mut constr, "#[no_mangle]\n/// Utility method to constructs a new {}-variant {}", var.ident, e.ident).unwrap();
+               let constr_name = camel_to_snake_case(&format!("{}", var.ident));
+               write!(&mut constr, "pub extern \"C\" fn {}_{}(", e.ident, constr_name).unwrap();
+               let mut empty_tuple_variant = false;
                if let syn::Fields::Named(fields) = &var.fields {
                        needs_free = true;
                        writeln!(w, " {{").unwrap();
-                       for field in fields.named.iter() {
+                       for (idx, field) in fields.named.iter().enumerate() {
                                if export_status(&field.attrs) == ExportStatus::TestOnly { continue; }
                                writeln_field_docs(w, &field.attrs, "\t\t", types, Some(&gen_types), &field.ty);
                                write!(w, "\t\t{}: ", field.ident.as_ref().unwrap()).unwrap();
+                               write!(&mut constr, "{}{}: ", if idx != 0 { ", " } else { "" }, field.ident.as_ref().unwrap()).unwrap();
                                types.write_c_type(w, &field.ty, Some(&gen_types), false);
+                               types.write_c_type(&mut constr, &field.ty, Some(&gen_types), false);
                                writeln!(w, ",").unwrap();
                        }
                        write!(w, "\t}}").unwrap();
                } else if let syn::Fields::Unnamed(fields) = &var.fields {
-                       let mut empty_tuple_variant = false;
                        if fields.unnamed.len() == 1 {
                                let mut empty_check = Vec::new();
                                types.write_c_type(&mut empty_check, &fields.unnamed[0].ty, Some(&gen_types), false);
@@ -1224,15 +1253,37 @@ fn writeln_enum<'a, 'b, W: std::io::Write>(w: &mut W, e: &'a syn::ItemEnum, type
                                write!(w, "(").unwrap();
                                for (idx, field) in fields.unnamed.iter().enumerate() {
                                        if export_status(&field.attrs) == ExportStatus::TestOnly { continue; }
+                                       write!(&mut constr, "{}: ", ('a' as u8 + idx as u8) as char).unwrap();
                                        types.write_c_type(w, &field.ty, Some(&gen_types), false);
+                                       types.write_c_type(&mut constr, &field.ty, Some(&gen_types), false);
                                        if idx != fields.unnamed.len() - 1 {
                                                write!(w, ",").unwrap();
+                                               write!(&mut constr, ",").unwrap();
                                        }
                                }
                                write!(w, ")").unwrap();
                        }
                }
                if var.discriminant.is_some() { unimplemented!(); }
+               write!(&mut constr, ") -> {} {{\n\t{}::{}", e.ident, e.ident, var.ident).unwrap();
+               if let syn::Fields::Named(fields) = &var.fields {
+                       writeln!(&mut constr, " {{").unwrap();
+                       for field in fields.named.iter() {
+                               writeln!(&mut constr, "\t\t{},", field.ident.as_ref().unwrap()).unwrap();
+                       }
+                       writeln!(&mut constr, "\t}}").unwrap();
+               } else if let syn::Fields::Unnamed(fields) = &var.fields {
+                       if !empty_tuple_variant {
+                               write!(&mut constr, "(").unwrap();
+                               for idx in 0..fields.unnamed.len() {
+                                       write!(&mut constr, "{}, ", ('a' as u8 + idx as u8) as char).unwrap();
+                               }
+                               writeln!(&mut constr, ")").unwrap();
+                       } else {
+                               writeln!(&mut constr, "").unwrap();
+                       }
+               }
+               writeln!(&mut constr, "}}").unwrap();
                writeln!(w, ",").unwrap();
        }
        writeln!(w, "}}\nuse {}::{} as native{};\nimpl {} {{", types.module_path, e.ident, e.ident, e.ident).unwrap();
@@ -1373,6 +1424,7 @@ fn writeln_enum<'a, 'b, W: std::io::Write>(w: &mut W, e: &'a syn::ItemEnum, type
        writeln!(w, "pub extern \"C\" fn {}_clone(orig: &{}) -> {} {{", e.ident, e.ident, e.ident).unwrap();
        writeln!(w, "\torig.clone()").unwrap();
        writeln!(w, "}}").unwrap();
+       w.write_all(&constr).unwrap();
        write_cpp_wrapper(cpp_headers, &format!("{}", e.ident), needs_free, None);
 }