// Copyright 2021 The Chromium Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. /// C++ bindings for base. /// /// This mod contains all the FFI bindings for C++ types in the base /// namespace. It should declare shared types, and the 'extern "C++"' /// section indicating C++ functions that are callable from Rust. /// /// Other [cxx::bridge] mods throughout the //base codebase may exist /// for exporting Rust functions to C++. /// /// C++ functions which exist only for the benefit of calls from /// Rust->C++ should live within the base::rs_glue C++ namespace. #[cxx::bridge(namespace=base::rs_glue)] pub(crate) mod ffi { unsafe extern "C++" { include!("base/rs_glue/values_glue.h"); /// C++ `base::Value` #[namespace=base] type Value; // Bindings to existing base::Value methods which happen to // line up with our needs precisely. #[cxx_name = "Append"] fn ValueAppendBool(self: Pin<&mut Value>, val: bool); #[cxx_name = "Append"] fn ValueAppendInteger(self: Pin<&mut Value>, val: i32); #[cxx_name = "Append"] fn ValueAppendDouble(self: Pin<&mut Value>, val: f64); // Free functions in C++ for cases where existing base::Value // APIs don't quite match our needs. // Set a key on a base::Value of type DICTIONARY to the given // value. fn ValueSetNoneKey(v: Pin<&mut Value>, key: &str); fn ValueSetBoolKey(v: Pin<&mut Value>, key: &str, val: bool); fn ValueSetIntegerKey(v: Pin<&mut Value>, key: &str, val: i32); fn ValueSetDoubleKey(v: Pin<&mut Value>, key: &str, val: f64); fn ValueSetStringKey(v: Pin<&mut Value>, key: &str, value: &str); // Returns a new child base::Value, of type DICTIONARY. fn ValueSetDictKey<'a>(v: Pin<&'a mut Value>, key: &str) -> Pin<&'a mut Value>; // Returns a new child base::Value, of type LIST. fn ValueSetListKey<'a>(v: Pin<&'a mut Value>, key: &str) -> Pin<&'a mut Value>; // Appends to a base::Value of type LIST. fn ValueAppendNone(v: Pin<&mut Value>); fn ValueAppendString(v: Pin<&mut Value>, value: &str); // Returns a new child base::Value, of type DICTIONARY. fn ValueAppendDict(v: Pin<&mut Value>) -> Pin<&mut Value>; // Returns a new child base::Value, of type LIST. fn ValueAppendList(v: Pin<&mut Value>) -> Pin<&mut Value>; fn ValueReserveSize(v: Pin<&mut Value>, len: usize); /// Represents a slot (on stack or heap) into which a new /// `base::Value` can be constructed. Only C++ code can construct /// such a slot. /// /// This type exists because we want to expose many functions /// which *construct* a `base::Value` which needs to live somewhere. /// For that reason, we can't simply extract a reference /// to the underlying base::Value because it doesn't yet exist. /// Future interop tools should support constructing a base::Value /// in Rust and moving it (by value). /// TODO(crbug.com/1272780): Use bindgen-like tools to generate /// direct bindings to C++ constructors. type ValueSlot; // Construct a base::Value of the given type, with the given value. fn ConstructNoneValue(v: Pin<&mut ValueSlot>); fn ConstructBoolValue(v: Pin<&mut ValueSlot>, val: bool); fn ConstructIntegerValue(v: Pin<&mut ValueSlot>, val: i32); fn ConstructDoubleValue(v: Pin<&mut ValueSlot>, val: f64); fn ConstructStringValue(v: Pin<&mut ValueSlot>, value: &str); // Returns a reference to the base::Value within the // `absl::optional` (which is of type DICTIONARY) // so that it can be populated. fn ConstructDictValue(v: Pin<&mut ValueSlot>) -> Pin<&mut Value>; // Returns a reference to the base::Value within the // `absl::optional` (which is of type LIST) // so that it can be populated. fn ConstructListValue(v: Pin<&mut ValueSlot>) -> Pin<&mut Value>; fn DumpValueSlot(v: &ValueSlot) -> String; // Defined for Rust tests to crate a ValueSlot, because it requires C++ to do the creation // at this time. fn NewValueSlotForTesting() -> UniquePtr; } }