cxx-qt-gen: add parsing phase of extern "C++Qt"

Related to KDAB#577

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

@@ -8,7 +8,10 @@ use crate::syntax::foreignmod::{foreign_mod_to_foreign_item_types, ForeignTypeId
 use crate::syntax::path::path_from_idents;
 use crate::syntax::safety::Safety;
 use crate::{
-    parser::{inherit::ParsedInheritedMethod, qobject::ParsedQObject, signals::ParsedSignal},
+    parser::{
+        externcxxqt::ParsedExternCxxQt, inherit::ParsedInheritedMethod, method::ParsedMethod,
+        qobject::ParsedQObject, signals::ParsedSignal,
+    },
     syntax::expr::expr_to_string,
 };
 use quote::format_ident;
@@ -18,8 +21,6 @@ use syn::{
     Result, Type, TypePath,
 };
 
-use super::method::ParsedMethod;
-
 #[derive(Default)]
 pub struct ParsedCxxMappings {
     /// Map of the cxx_name of any types defined in CXX extern blocks
@@ -60,6 +61,8 @@ pub struct ParsedCxxQtData {
     // We have to use a BTreeMap here, instead of a HashMap, to keep the order of QObjects stable.
     // Otherwise, the output order would be different, depending on the environment, which makes it hard to test/debug.
     pub qobjects: BTreeMap<Ident, ParsedQObject>,
+    /// Blocks of extern "C++Qt"
+    pub extern_cxx_blocks: Vec<ParsedExternCxxQt>,
     /// The namespace of the CXX-Qt module
     pub namespace: String,
     /// The ident of the module, used for mappings
@@ -73,6 +76,7 @@ impl ParsedCxxQtData {
             cxx_mappings: ParsedCxxMappings::default(),
             qualified_mappings: BTreeMap::<Ident, Path>::default(),
             qobjects: BTreeMap::<Ident, ParsedQObject>::default(),
+            extern_cxx_blocks: Vec::<ParsedExternCxxQt>::default(),
             module_ident,
             namespace,
         }
@@ -249,7 +253,12 @@ impl ParsedCxxQtData {
                     self.parse_foreign_mod_rust_qt(foreign_mod)?;
                     return Ok(None);
                 }
-                // TODO: look for "C++Qt" later
+                "C++Qt" => {
+                    self.populate_mappings_from_foreign_mod_item(&foreign_mod)?;
+                    self.extern_cxx_blocks
+                        .push(ParsedExternCxxQt::parse(foreign_mod)?);
+                    return Ok(None);
+                }
                 _others => {}
             }
         }
@@ -566,6 +575,29 @@ mod tests {
         assert!(cxx_qt_data.qobjects[&qobject_ident()].threading);
     }
 
+    #[test]
+    fn test_find_and_merge_cxx_qt_item_extern_cxx_qt() {
+        let mut cxx_qt_data = create_parsed_cxx_qt_data();
+
+        let item: Item = parse_quote! {
+            #[namespace = "rust"]
+            unsafe extern "C++Qt" {
+                type QPushButton;
+
+                #[qsignal]
+                fn clicked(self: Pin<&mut QPushButton>, checked: bool);
+            }
+        };
+        let result = cxx_qt_data.parse_cxx_qt_item(item).unwrap();
+        assert!(result.is_none());
+
+        assert_eq!(cxx_qt_data.extern_cxx_blocks.len(), 1);
+        assert_eq!(cxx_qt_data.extern_cxx_blocks[0].attrs.len(), 1);
+        assert_eq!(cxx_qt_data.extern_cxx_blocks[0].passthrough_items.len(), 1);
+        assert_eq!(cxx_qt_data.extern_cxx_blocks[0].signals.len(), 1);
+        assert!(cxx_qt_data.extern_cxx_blocks[0].unsafety.is_some());
+    }
+
     #[test]
     fn test_cxx_mappings_cxx_name_empty() {
         let mut cxx_qt_data = create_parsed_cxx_qt_data();

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

@@ -0,0 +1,86 @@
+// SPDX-FileCopyrightText: 2023 Klarälvdalens Datakonsult AB, a KDAB Group company <[email protected]>
+// SPDX-FileContributor: Andrew Hayzen <[email protected]>
+//
+// SPDX-License-Identifier: MIT OR Apache-2.0
+
+use crate::{
+    parser::signals::ParsedSignal,
+    syntax::{attribute::attribute_find_path, safety::Safety},
+};
+use syn::{Attribute, ForeignItem, ItemForeignMod, Result, Token};
+
+/// Representation of an extern "C++Qt" block
+#[derive(Default)]
+pub struct ParsedExternCxxQt {
+    /// Attributes for the extern "C++Qt" block
+    pub attrs: Vec<Attribute>,
+    /// Whether this block has an unsafe token
+    pub unsafety: Option<Token![unsafe]>,
+    /// Items which can be passed into the extern "C++Qt" block
+    pub passthrough_items: Vec<ForeignItem>,
+    /// Signals that need generation in the extern "C++Qt" block
+    pub signals: Vec<ParsedSignal>,
+}
+
+impl ParsedExternCxxQt {
+    pub fn parse(mut foreign_mod: ItemForeignMod) -> Result<Self> {
+        let mut extern_cxx_block = ParsedExternCxxQt {
+            attrs: foreign_mod.attrs.clone(),
+            unsafety: foreign_mod.unsafety,
+            ..Default::default()
+        };
+
+        let safe_call = if foreign_mod.unsafety.is_some() {
+            Safety::Safe
+        } else {
+            Safety::Unsafe
+        };
+
+        // Parse any signals, other items are passed through
+        for item in foreign_mod.items.drain(..) {
+            if let ForeignItem::Fn(foreign_fn) = &item {
+                // Test if the function is a signal
+                if let Some(index) = attribute_find_path(&foreign_fn.attrs, &["qsignal"]) {
+                    let mut foreign_fn = foreign_fn.clone();
+                    // Remove the signals attribute
+                    foreign_fn.attrs.remove(index);
+
+                    extern_cxx_block
+                        .signals
+                        .push(ParsedSignal::parse(foreign_fn, safe_call)?);
+                    continue;
+                }
+            }
+
+            extern_cxx_block.passthrough_items.push(item);
+        }
+
+        Ok(extern_cxx_block)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    use syn::parse_quote;
+
+    #[test]
+    fn test_find_and_merge_cxx_qt_item_extern_cxx_qt() {
+        let extern_cxx_qt = ParsedExternCxxQt::parse(parse_quote! {
+            #[namespace = "rust"]
+            unsafe extern "C++Qt" {
+                type QPushButton;
+
+                #[qsignal]
+                fn clicked(self: Pin<&mut QPushButton>, checked: bool);
+            }
+        })
+        .unwrap();
+
+        assert_eq!(extern_cxx_qt.attrs.len(), 1);
+        assert_eq!(extern_cxx_qt.passthrough_items.len(), 1);
+        assert_eq!(extern_cxx_qt.signals.len(), 1);
+        assert!(extern_cxx_qt.unsafety.is_some());
+    }
+}

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

@@ -5,6 +5,7 @@
 
 pub mod constructor;
 pub mod cxxqtdata;
+pub mod externcxxqt;
 pub mod inherit;
 pub mod method;
 pub mod parameter;
@@ -76,7 +77,7 @@ impl Parser {
             // Loop through items and load into qobject or others and populate mappings
             for item in items.1.drain(..) {
                 // Try to find any CXX-Qt items, if found add them to the relevant
-                // qobject. Otherwise return them to be added to other
+                // qobject or extern C++Qt block. Otherwise return them to be added to other
                 if let Some(other) = cxx_qt_data.parse_cxx_qt_item(item)? {
                     // Load any CXX name mappings
                     cxx_qt_data.populate_mappings_from_item(&other)?;