Revert "compiler: inline components that are used only once" (#7697)

This reverts commit bf716ff.
(And also revert the test part of 259756c)

This exposed the bug #7693 and more issues mentined in
#7693 (comment)

Fixes #7693
CC #7680

Author: ogoffart

internal/compiler/passes/inlining.rs

@@ -23,15 +23,14 @@ pub fn inline(doc: &Document, inline_selection: InlineSelection, diag: &mut Buil
     fn inline_components_recursively(
         component: &Rc<Component>,
         roots: &HashSet<ByAddress<Rc<Component>>>,
-        used_once: &HashSet<ByAddress<Rc<Component>>>,
         inline_selection: InlineSelection,
         diag: &mut BuildDiagnostics,
     ) {
         recurse_elem_no_borrow(&component.root_element, &(), &mut |elem, _| {
             let base = elem.borrow().base_type.clone();
             if let ElementType::Component(c) = base {
                 // First, make sure that the component itself is properly inlined
-                inline_components_recursively(&c, roots, used_once, inline_selection, diag);
+                inline_components_recursively(&c, roots, inline_selection, diag);
 
                 if c.parent_element.upgrade().is_some() {
                     // We should not inline a repeated element
@@ -49,27 +48,24 @@ pub fn inline(doc: &Document, inline_selection: InlineSelection, diag: &mut Buil
                             || component.parent_element.upgrade().is_none() && Rc::ptr_eq(elem, &component.root_element)
                             // We always inline other roots as a component can't be both a sub component and a root
                             || roots.contains(&ByAddress(c.clone()))
-                            || used_once.contains(&ByAddress(c.clone()))
                     }
                 } {
                     inline_element(elem, &c, component, diag);
                 }
             }
         });
         component.popup_windows.borrow().iter().for_each(|p| {
-            inline_components_recursively(&p.component, roots, used_once, inline_selection, diag)
+            inline_components_recursively(&p.component, roots, inline_selection, diag)
         })
     }
     let mut roots = HashSet::new();
-    let mut used_once = HashSet::new();
     if inline_selection == InlineSelection::InlineOnlyRequiredComponents {
         for component in doc.exported_roots().chain(doc.popup_menu_impl.iter().cloned()) {
             roots.insert(ByAddress(component.clone()));
         }
-        used_once = collect_subcomponents_used_once(doc);
     }
     for component in doc.exported_roots().chain(doc.popup_menu_impl.iter().cloned()) {
-        inline_components_recursively(&component, &roots, &used_once, inline_selection, diag);
+        inline_components_recursively(&component, &roots, inline_selection, diag);
         let mut init_code = component.init_code.borrow_mut();
         let inlined_init_code = core::mem::take(&mut init_code.inlined_init_code);
         init_code.constructor_code.splice(0..0, inlined_init_code.into_values());
@@ -655,35 +651,3 @@ fn element_require_inlining(elem: &ElementRc) -> bool {
 
     false
 }
-
-fn collect_subcomponents_used_once(doc: &Document) -> HashSet<ByAddress<Rc<Component>>> {
-    fn recursive(component: &Rc<Component>, hash: &mut HashMap<ByAddress<Rc<Component>>, bool>) {
-        match hash.entry(ByAddress(component.clone())) {
-            std::collections::hash_map::Entry::Occupied(mut o) => {
-                if !*o.get() {
-                    // We have already set this element (and its children to "set multiple times"
-                    return;
-                }
-                // Element used multiple times, visit all children to set them to multiple times too.
-                *o.get_mut() = false;
-            }
-            std::collections::hash_map::Entry::Vacant(v) => {
-                v.insert(true);
-            }
-        }
-
-        recurse_elem(&component.root_element, &(), &mut |elem: &ElementRc, &()| {
-            let ElementType::Component(base_comp) = &elem.borrow().base_type else { return };
-            recursive(base_comp, hash);
-        });
-        for popup in component.popup_windows.borrow().iter() {
-            recursive(&popup.component, hash);
-        }
-    }
-    // Stores true for elements that are used once, false for elements that are used multiple times;
-    let mut result = HashMap::new();
-    for component in doc.exported_roots().chain(doc.popup_menu_impl.iter().cloned()) {
-        recursive(&component, &mut result);
-    }
-    result.into_iter().filter(|(_, v)| *v).map(|(k, _)| k).collect()
-}

internal/compiler/tests/syntax/analysis/binding_loop_layout.slint

@@ -2,6 +2,7 @@
 // SPDX-License-Identifier: GPL-3.0-only OR LicenseRef-Slint-Royalty-free-2.0 OR LicenseRef-Slint-Software-3.0
 
 TC := Rectangle {
+//    ^error{The binding for the property 'layoutinfo-h' is part of a binding loop}
     outer := VerticalLayout {
 //           ^error{The binding for the property 'width' is part of a binding loop}
 //           ^^error{The binding for the property 'layoutinfo-h' is part of a binding loop}
@@ -45,7 +46,6 @@ export Test := Rectangle {
 
     tc := TC {
 //        ^error{The binding for the property 'preferred-width' is part of a binding loop}
-//        ^^error{The binding for the property 'layoutinfo-h' is part of a binding loop}
         width: preferred-width;
 //             ^error{The binding for the property 'width' is part of a binding loop}
     }

internal/compiler/tests/syntax/analysis/binding_loop_layout3.slint

@@ -2,6 +2,7 @@
 // SPDX-License-Identifier: GPL-3.0-only OR LicenseRef-Slint-Royalty-free-2.0 OR LicenseRef-Slint-Software-3.0
 
 Compo := Rectangle {
+//       ^error{The binding for the property 'layoutinfo-h' is part of a binding loop}
 
     property <string> the_text;
 
@@ -24,7 +25,6 @@ Compo := Rectangle {
 export Foo := Rectangle {
     Compo {
 //  ^error{The binding for the property 'preferred-width' is part of a binding loop}
-//  ^^error{The binding for the property 'layoutinfo-h' is part of a binding loop}
         the_text: self.preferred-width / 1px;
 //                ^error{The binding for the property 'the-text' is part of a binding loop}
     }

internal/compiler/tests/syntax/analysis/binding_loop_layout4.slint

@@ -24,6 +24,7 @@ component Foo {
 }
 
 component Bar {
+//            ^error{The binding for the property 'layoutinfo-h' is part of a binding loop}
     HorizontalLayout {
 //  ^error{The binding for the property 'layout-cache' is part of a binding loop}
 //  ^^error{The binding for the property 'width' is part of a binding loop}
@@ -39,6 +40,4 @@ export component Apps inherits Window {
     Bar {}
 //  ^error{The binding for the property 'preferred-width' is part of a binding loop}
 //  ^^error{The binding for the property 'width' is part of a binding loop}
-//  ^^^error{The binding for the property 'layoutinfo-h' is part of a binding loop}
-//  ^^^^error{The binding for the property 'min-width' is part of a binding loop}
 }

internal/compiler/tests/syntax/analysis/binding_loop_layout_if.slint

@@ -15,6 +15,7 @@ component Wrapper {
 }
 
 component WrapperInherited inherits Rectangle {
+//                                  ^error{The binding for the property 'layoutinfo-h' is part of a binding loop}
     VerticalLayout {
 //  ^error{The binding for the property 'layoutinfo-h' is part of a binding loop}
         if root.width > 200px: Rectangle { }
@@ -29,9 +30,8 @@ export component Test inherits Window {
 //      ^^error{The binding for the property 'width' is part of a binding loop}
 //      ^^^error{The binding for the property 'layout-cache' is part of a binding loop}
             WrapperInherited { }
-//          ^error{The binding for the property 'layoutinfo-h' is part of a binding loop}
             Wrapper { }
 //          ^error{The binding for the property 'layoutinfo-h' is part of a binding loop}
         }
     }
-}
+}

internal/compiler/tests/syntax/basic/dialog.slint

@@ -11,6 +11,7 @@ MyDiag1 := Dialog {
 }
 
 MyDiag2 := Dialog {
+//         ^error{A Dialog must have a single child element that is not StandardButton}
     StandardButton { kind: reset; }
     StandardButton {
         kind: cancel;
@@ -54,7 +55,6 @@ MyDialog4 := Dialog {
 export Test := Rectangle {
     MyDiag1 {}
     MyDiag2 {}
-//  ^error{A Dialog must have a single child element that is not StandardButton}
     MyDiag3 {}
     MyDialog4 {}
 }