cxx-qt-gen: use extern "RustQt" block for inherit and signals

Closes #557

CHANGELOG.md

@@ -28,6 +28,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Always call `qt_build_utils::setup_linker()` in `CxxQtBuilder` and remove the proxy method
 - Moved to `syn` 2.0 internally and for any exported `syn` types
 - `impl cxx_qt::Threading for qobject::T` now needs to be specified for `qt_thread()` to be available
+- `#[cxx_qt::qsignals]` and `#[cxx_qt::inherit]` are now used in an `extern "RustQt"` block as `#[qsignal]` and `#[inherit]`
 
 ### Removed
 

book/src/SUMMARY.md

@@ -20,7 +20,7 @@ SPDX-License-Identifier: MIT OR Apache-2.0
 - [QObject](./qobject/index.md)
     - [`#[cxx_qt::bridge]` - Bridge Macro](./qobject/bridge-macro.md)
     - [`#[cxx_qt::qobject]` - Defining QObjects](./qobject/qobject_struct.md)
-    - [`#[cxx_qt::qsignals]` - Signals macro](./qobject/signals.md)
+    - [`#[qsignal]` - Signal macro](./qobject/signals.md)
     - [`qobject::T` - The generated QObject](./qobject/generated-qobject.md)
     - [CxxQtThread](./qobject/cxxqtthread.md)
 - [Concepts](./concepts/index.md)

book/src/concepts/inheritance.md

@@ -12,8 +12,8 @@ Some Qt APIs require you to override certain methods from an abstract base class
 To support creating such subclasses directly from within Rust, CXX-Qt provides you with multiple helpers.
 
 ## Accessing base class methods
-To access the methods of a base class in Rust, use the `#[cxx_qt::inherit]` macro.
-It can be placed in front of an `extern "C++"` block in a `#[cxx_qt::bridge]`.
+To access the methods of a base class in Rust, use the `#[inherit]` macro.
+It can be placed in front of a function in a `extern "RustQt"` block in a `#[cxx_qt::bridge]`.
 
 ```rust,ignore
 {{#include ../../../examples/qml_features/rust/src/custom_base_class.rs:book_inherit_qalm}}
@@ -27,10 +27,10 @@ It can be placed in front of an `extern "C++"` block in a `#[cxx_qt::bridge]`.
 [Full example](https://github.com/KDAB/cxx-qt/blob/main/examples/qml_features/rust/src/custom_base_class.rs)
 
 This code implements a QAbstractListModel subclass.
-For this, the `clear` method implemented in Rust needs to call `beginResetModel` and related methods from the base class, which are made accessible by using `#[cxx_qt::inherit]`.
+For this, the `clear` method implemented in Rust needs to call `beginResetModel` and related methods from the base class, which are made accessible by using `#[inherit]`.
 See [the Qt docs](https://doc.qt.io/qt-6/qabstractlistmodel.html) for more details on the specific subclassing requirements.
 
-Methods can be declared inside `#[cxx_qt::inherit]` in `extern "C++"` blocks similar to CXX, with the same restrictions regarding which types can be used.
+Methods in a `extern "RustQt"` block similar to CXX can be tagged with an `#[inherit]` attribute, with the same restrictions regarding which types can be used.
 Additionally, the `self` type must be either `self: Pin<&mut qobject::T>` or `self: &qobject::T`, where `qobject::T` must refer to a QObject marked with `#[cxx_qt::qobject]` in the `#[cxx_qt::bridge]`
 
 The declared methods will be case-converted as in other CXX-Qt APIs.
@@ -58,7 +58,7 @@ The below example overrides the [`data`](https://doc.qt.io/qt-6/qabstractitemmod
 ```
 [Full example](https://github.com/KDAB/cxx-qt/blob/main/examples/qml_features/rust/src/custom_base_class.rs)
 
-When a method is overridden using `cxx_override`, the base class version of the method can be accessed by using `#[cxx_qt::inherit]` in combination with the `#[cxx_name]` attribute.
+When a method is overridden using `cxx_override`, the base class version of the method can be accessed by using `#[inherit]` in combination with the `#[cxx_name]` attribute.
 In this case the base class version of the function must get a different name because Rust can't have two functions with the same name on one type.
 
 Example:

book/src/getting-started/1-qobjects-in-rust.md

@@ -47,7 +47,7 @@ Then you can use the afformentioned features with the help of more macros.
 - `#[cxx_qt::qobject]` - Expose a Rust struct to Qt as a QObject subclass.
     - `#[qproperty]` - Expose a field of the Rust struct to QML/C++ as a [`Q_PROPERTY`](https://doc.qt.io/qt-6/qtqml-cppintegration-exposecppattributes.html#exposing-properties).
     - `#[qinvokable]` - Expose a function on the QObject to QML and C++ as a [`Q_INVOKABLE`](https://doc.qt.io/qt-6/qtqml-cppintegration-exposecppattributes.html#exposing-methods-including-qt-slots).
-- `#[cxx_qt::qsignals]` - Define the [Signals](https://doc.qt.io/qt-6/signalsandslots.html#signals) of a QObject T.
+    - `#[qsignal]` - Define the [Signals](https://doc.qt.io/qt-6/signalsandslots.html#signals) of a QObject T.
 
 CXX-Qt will then expand this Rust module into two separate parts:
 - C++ files that define a QObject subclass for each `#[cxx_qt::qobject]` marked struct.

book/src/qobject/index.md

@@ -15,7 +15,7 @@ For a simpler introduction, take a look at our [Getting Started guide](../gettin
 QObject Features and Parts:
   * [`#[cxx_qt::bridge]` - The macro around the module](./bridge-macro.md)
   * [`#[cxx_qt::qobject]` - Marking a Rust struct as a QObject](./qobject_struct.md)
-  * [`#[cxx_qt::qsignals]` - A macro for defining signals](./signals.md)
+  * [`#[qsignal]` - A macro for defining signals](./signals.md)
   * [`qobject:T` - The generated QObject](./generated-qobject.md)
   * [`CxxQtThread` - Queueing closures onto the Qt event loop](./cxxqtthread.md)
 

book/src/qobject/qobject_struct.md

@@ -27,7 +27,7 @@ The macro does multiple other things for you though:
 - Expose the generated QObject subclass to Rust as [`qobject::MyObject`](./generated-qobject.md)
 - Generate getters/setters for all fields.
 - Generate `Q_PROPERTY`s for all fields that are marked as `#[qproperty]`.
-- Generate signals if paired with a [`#[cxx_qt::qsignals]` macro](./signals.md).
+- Generate signals if paired with a [`#[qsignal]` macro](./signals.md).
 
 ## Exposing to QML
 `#[cxx_qt::qobject]` supports registering the Qt object as a QML type directly at build time.

book/src/qobject/signals.md

@@ -5,9 +5,9 @@ SPDX-FileContributor: Andrew Hayzen <[email protected]>
 SPDX-License-Identifier: MIT OR Apache-2.0
 -->
 
-# Signals enum
+# Signals
 
-The `cxx_qt::qsignals` attribute is used on an `extern "C++"` block to define [signals](https://doc.qt.io/qt-6/signalsandslots.html) for the a QObject.
+The `qsignal` attribute is used in an `extern "RustQt"` block to define [signals](https://doc.qt.io/qt-6/signalsandslots.html) for the a QObject.
 
 ```rust,ignore,noplayground
 {{#include ../../../examples/qml_features/rust/src/signals.rs:book_signals_block}}
@@ -57,7 +57,7 @@ In this case, it is no longer possible to disconnect later.
 
 ## Emitting a signal
 
-Call the function signature defined in the `extern "C++` block to emit the signal.
+Call the function signature defined in the `extern "RustQt"` block to emit the signal.
 
 Note that these are defined on the generated QObject [`qobject::T`](./generated-qobject.md), so can be called from any mutable `#[qinvokable]`.
 

crates/cxx-qt-gen/src/parser/cxxqtdata.rs

@@ -4,18 +4,14 @@
 // SPDX-License-Identifier: MIT OR Apache-2.0
 
 use crate::syntax::foreignmod::foreign_mod_to_foreign_item_types;
+use crate::syntax::safety::Safety;
 use crate::syntax::{attribute::attribute_find_path, path::path_to_single_ident};
 use crate::{
-    parser::{
-        inherit::{InheritMethods, ParsedInheritedMethod},
-        qobject::ParsedQObject,
-        signals::{ParsedSignal, SignalMethods},
-    },
+    parser::{inherit::ParsedInheritedMethod, qobject::ParsedQObject, signals::ParsedSignal},
     syntax::expr::expr_to_string,
 };
-use proc_macro2::TokenStream;
-use quote::ToTokens;
 use std::collections::BTreeMap;
+use syn::ForeignItem;
 use syn::{
     spanned::Spanned, Attribute, Error, Ident, Item, ItemForeignMod, ItemImpl, Result, Type,
     TypePath,
@@ -184,75 +180,60 @@ impl ParsedCxxQtData {
         }
     }
 
-    fn parse_inherit_mod(&mut self, tokens: TokenStream) -> Result<()> {
-        let inherited: InheritMethods = syn::parse2(tokens)?;
-
-        self.add_inherited_methods(inherited)
-    }
-
-    fn add_inherited_methods(&mut self, inherited: InheritMethods) -> Result<()> {
-        for method in inherited.base_functions.into_iter() {
-            let parsed_inherited_method = ParsedInheritedMethod::parse(method, inherited.safety)?;
-
-            if let Some(ref mut qobject) = self
-                .qobjects
-                .get_mut(&parsed_inherited_method.qobject_ident)
-            {
-                qobject.inherited_methods.push(parsed_inherited_method);
-            } else {
-                return Err(Error::new_spanned(
-                    parsed_inherited_method.qobject_ident,
-                    "No QObject with this name found.",
-                ));
+    fn parse_foreign_mod(&mut self, foreign_mod: ItemForeignMod) -> Result<Option<Item>> {
+        if let Some(lit_str) = &foreign_mod.abi.name {
+            match lit_str.value().as_str() {
+                "RustQt" => {
+                    self.parse_foreign_mod_rust_qt(foreign_mod)?;
+                    return Ok(None);
+                }
+                // TODO: look for "C++Qt" later
+                _others => {}
             }
         }
-        Ok(())
-    }
-
-    fn parse_signals_mod(&mut self, tokens: TokenStream) -> Result<()> {
-        let signals: SignalMethods = syn::parse2(tokens)?;
 
-        self.add_signal_methods(signals)
-    }
-
-    fn add_signal_methods(&mut self, signals: SignalMethods) -> Result<()> {
-        for method in signals.base_functions.into_iter() {
-            let parsed_signal_method = ParsedSignal::parse(method, signals.safety)?;
-
-            if let Some(ref mut qobject) =
-                self.qobjects.get_mut(&parsed_signal_method.qobject_ident)
-            {
-                qobject.signals.push(parsed_signal_method);
-            } else {
-                return Err(Error::new_spanned(
-                    parsed_signal_method.qobject_ident,
-                    "No QObject with this name found.",
-                ));
-            }
-        }
-        Ok(())
+        Ok(Some(Item::ForeignMod(foreign_mod)))
     }
 
-    fn parse_foreign_mod(&mut self, mut foreign_mod: ItemForeignMod) -> Result<Option<Item>> {
-        // Check if the foreign mod has cxx_qt::inherit on it
-        if let Some(index) = attribute_find_path(&foreign_mod.attrs, &["cxx_qt", "inherit"]) {
-            // Remove the inherit attribute
-            foreign_mod.attrs.remove(index);
-
-            self.parse_inherit_mod(foreign_mod.into_token_stream())?;
-            return Ok(None);
-        }
+    fn parse_foreign_mod_rust_qt(&mut self, mut foreign_mod: ItemForeignMod) -> Result<()> {
+        let safe_call = if foreign_mod.unsafety.is_some() {
+            Safety::Safe
+        } else {
+            Safety::Unsafe
+        };
 
-        // Check if the foreign mod has cxx_qt::qsignals on it
-        if let Some(index) = attribute_find_path(&foreign_mod.attrs, &["cxx_qt", "qsignals"]) {
-            // Remove the signals attribute
-            foreign_mod.attrs.remove(index);
+        for item in foreign_mod.items.drain(..) {
+            if let ForeignItem::Fn(mut foreign_fn) = item {
+                // Test if the function is a signal
+                if let Some(index) = attribute_find_path(&foreign_fn.attrs, &["qsignal"]) {
+                    // Remove the signals attribute
+                    foreign_fn.attrs.remove(index);
+
+                    let parsed_signal_method = ParsedSignal::parse(foreign_fn, safe_call)?;
+
+                    self.with_qobject(&parsed_signal_method.qobject_ident)?
+                        .signals
+                        .push(parsed_signal_method);
+                // Test if the function is an inheritance method
+                //
+                // Note that we need to test for qsignal first as qsignals have their own inherit meaning
+                } else if let Some(index) = attribute_find_path(&foreign_fn.attrs, &["inherit"]) {
+                    // Remove the inherit attribute
+                    foreign_fn.attrs.remove(index);
+
+                    let parsed_inherited_method =
+                        ParsedInheritedMethod::parse(foreign_fn, safe_call)?;
+
+                    self.with_qobject(&parsed_inherited_method.qobject_ident)?
+                        .inherited_methods
+                        .push(parsed_inherited_method);
+                }
 
-            self.parse_signals_mod(foreign_mod.into_token_stream())?;
-            return Ok(None);
+                // TODO: test for qinvokable later
+            }
         }
 
-        Ok(Some(Item::ForeignMod(foreign_mod)))
+        Ok(())
     }
 
     /// Parse a [syn::ItemImpl] into the qobjects if it's a CXX-Qt implementation
@@ -287,6 +268,17 @@ impl ParsedCxxQtData {
 
         Ok(Some(Item::Impl(imp)))
     }
+
+    fn with_qobject(&mut self, qobject_ident: &Ident) -> Result<&mut ParsedQObject> {
+        if let Some(qobject) = self.qobjects.get_mut(qobject_ident) {
+            Ok(qobject)
+        } else {
+            Err(Error::new_spanned(
+                qobject_ident,
+                "No QObject with this name found.",
+            ))
+        }
+    }
 }
 
 #[cfg(test)]
@@ -732,17 +724,18 @@ mod tests {
         let mut cxxqtdata = create_parsed_cxx_qt_data();
 
         let unsafe_block: Item = parse_quote! {
-            #[cxx_qt::inherit]
-            unsafe extern "C++" {
+            unsafe extern "RustQt" {
+                #[inherit]
                 fn test(self: &qobject::MyObject);
 
+                #[inherit]
                 fn with_args(self: &qobject::MyObject, arg: i32);
             }
         };
         let safe_block: Item = parse_quote! {
-            #[cxx_qt::inherit]
-            extern "C++" {
+            extern "RustQt" {
                 #[cxx_name="withRename"]
+                #[inherit]
                 unsafe fn with_rename(self: Pin<&mut qobject::MyObject>, arg: i32);
             }
         };
@@ -771,12 +764,13 @@ mod tests {
     fn test_parse_qsignals_safe() {
         let mut cxxqtdata = create_parsed_cxx_qt_data();
         let block: Item = parse_quote! {
-            #[cxx_qt::qsignals]
-            unsafe extern "C++" {
+            unsafe extern "RustQt" {
+                #[qsignal]
                 fn ready(self: Pin<&mut qobject::MyObject>);
 
                 #[cxx_name="cppDataChanged"]
                 #[inherit]
+                #[qsignal]
                 fn data_changed(self: Pin<&mut qobject::MyObject>, data: i32);
             }
         };
@@ -815,8 +809,8 @@ mod tests {
     fn test_parse_qsignals_unknown_obj() {
         let mut cxxqtdata = create_parsed_cxx_qt_data();
         let block: Item = parse_quote! {
-            #[cxx_qt::qsignals]
-            unsafe extern "C++" {
+            unsafe extern "RustQt" {
+                #[qsignal]
                 fn ready(self: Pin<&mut qobject::UnknownObj>);
             }
         };
@@ -827,8 +821,8 @@ mod tests {
     fn test_parse_qsignals_unsafe() {
         let mut cxxqtdata = create_parsed_cxx_qt_data();
         let block: Item = parse_quote! {
-            #[cxx_qt::qsignals]
-            extern "C++" {
+            extern "RustQt" {
+                #[qsignal]
                 unsafe fn unsafe_signal(self: Pin<&mut qobject::MyObject>, arg: *mut T);
             }
         };