Compiler: Change a new error from 1.9 to a warning

To keep compatibility with existing Slint code

Commit 53e7900 added a call to
LayoutConstraints::new which is shown to produce error in the crater
run.

internal/compiler/layout.rs

@@ -3,7 +3,7 @@
 
 //! Datastructures used to represent layouts in the compiler
 
-use crate::diagnostics::BuildDiagnostics;
+use crate::diagnostics::{BuildDiagnostics, DiagnosticLevel, Spanned};
 use crate::expression_tree::*;
 use crate::langtype::{ElementType, PropertyLookupResult, Type};
 use crate::object_tree::{Component, ElementRc};
@@ -134,7 +134,11 @@ pub struct LayoutConstraints {
 }
 
 impl LayoutConstraints {
-    pub fn new(element: &ElementRc, diag: &mut BuildDiagnostics) -> Self {
+    /// Build the constraints for the given element
+    ///
+    /// Report diagnostics when both constraints and fixed size are set
+    /// (one can set the level to warning to keep compatibility to old version of Slint)
+    pub fn new(element: &ElementRc, diag: &mut BuildDiagnostics, level: DiagnosticLevel) -> Self {
         let mut constraints = Self {
             min_width: binding_reference(element, "min-width"),
             max_width: binding_reference(element, "max-width"),
@@ -162,14 +166,14 @@ impl LayoutConstraints {
                                 && old.priority.saturating_add(d2)
                                     <= binding.priority.saturating_add(depth)
                             {
-                                diag.push_error(
+                                diag.push_diagnostic_with_span(
                                     format!(
-                                        "Cannot specify both '{}' and '{}'",
-                                        prop,
+                                        "Cannot specify both '{prop}' and '{}'",
                                         other_prop.name()
                                     ),
-                                    binding,
-                                )
+                                    binding.to_source_location(),
+                                    level,
+                                );
                             }
                         },
                     );

internal/compiler/passes/default_geometry.rs

@@ -12,7 +12,7 @@
 use std::cell::RefCell;
 use std::rc::Rc;
 
-use crate::diagnostics::{BuildDiagnostics, Spanned};
+use crate::diagnostics::{BuildDiagnostics, DiagnosticLevel, Spanned};
 use crate::expression_tree::{
     BindingExpression, BuiltinFunction, Expression, MinMaxOp, NamedReference, Unit,
 };
@@ -187,7 +187,8 @@ fn gen_layout_info_prop(elem: &ElementRc, diag: &mut BuildDiagnostics) {
                         // FIXME: we should ideally add runtime code to merge layout info of all elements that are repeated (same as #407)
                         return None;
                     }
-                    let explicit_constraints = LayoutConstraints::new(c, diag);
+                    let explicit_constraints =
+                        LayoutConstraints::new(c, diag, DiagnosticLevel::Error);
                     let use_implicit_size = c.borrow().builtin_type().map_or(false, |b| {
                         b.default_size_binding == DefaultSizeBinding::ImplicitSize
                     });
@@ -223,7 +224,7 @@ fn gen_layout_info_prop(elem: &ElementRc, diag: &mut BuildDiagnostics) {
     let mut expr_h = implicit_layout_info_call(elem, Orientation::Horizontal);
     let mut expr_v = implicit_layout_info_call(elem, Orientation::Vertical);
 
-    let explicit_constraints = LayoutConstraints::new(elem, diag);
+    let explicit_constraints = LayoutConstraints::new(elem, diag, DiagnosticLevel::Warning);
     if !explicit_constraints.fixed_width {
         merge_explicit_constraints(&mut expr_h, &explicit_constraints, Orientation::Horizontal);
     }

internal/compiler/passes/lower_layout.rs

@@ -5,8 +5,7 @@
 
 use lyon_path::geom::euclid::approxeq::ApproxEq;
 
-use crate::diagnostics::BuildDiagnostics;
-use crate::diagnostics::Spanned;
+use crate::diagnostics::{BuildDiagnostics, DiagnosticLevel, Spanned};
 use crate::expression_tree::*;
 use crate::langtype::ElementType;
 use crate::langtype::Type;
@@ -43,7 +42,7 @@ pub fn lower_layouts(
     });
 
     *component.root_constraints.borrow_mut() =
-        LayoutConstraints::new(&component.root_element, diag);
+        LayoutConstraints::new(&component.root_element, diag, DiagnosticLevel::Error);
 
     recurse_elem_including_sub_components(component, &(), &mut |elem, _| {
         let component = elem.borrow().enclosing_component.upgrade().unwrap();
@@ -724,7 +723,7 @@ fn create_layout_item(
         fix_explicit_percent("height", &rep_comp.root_element);
 
         *rep_comp.root_constraints.borrow_mut() =
-            LayoutConstraints::new(&rep_comp.root_element, diag);
+            LayoutConstraints::new(&rep_comp.root_element, diag, DiagnosticLevel::Error);
         rep_comp.root_element.borrow_mut().child_of_layout = true;
         (
             Some(if r.is_conditional_element {
@@ -738,7 +737,7 @@ fn create_layout_item(
         (None, item_element.clone())
     };
 
-    let constraints = LayoutConstraints::new(&actual_elem, diag);
+    let constraints = LayoutConstraints::new(&actual_elem, diag, DiagnosticLevel::Error);
     Some(CreateLayoutItemResult {
         item: LayoutItem { element: item_element.clone(), constraints },
         elem: actual_elem,

internal/compiler/tests/syntax/layout/min_max_conflict.slint

@@ -1,7 +1,7 @@
 // Copyright © SixtyFPS GmbH <[email protected]>
 // SPDX-License-Identifier: GPL-3.0-only OR LicenseRef-Slint-Royalty-free-2.0 OR LicenseRef-Slint-Software-3.0
 
-export Test := Rectangle {
+export component Test inherits Rectangle {
 
     GridLayout {
         Rectangle {
@@ -18,5 +18,28 @@ export Test := Rectangle {
         }
     }
 
+    // outside a layout
+    Rectangle {
+        width: 42px;
+//             ^error{Cannot specify both 'width' and 'min-width'}
+        min-width: 5rem;
+    }
+
+    Rectangle {
+        // Slint 1.8 and earlier did not complain about extra specifications when the item is not in a layout
+        // contains a layout that's why it's a warning instead now
+        height: 10rem;
+//              ^warning{Cannot specify both 'height' and 'min-height'}
+        min-height: 8rem;
+        HorizontalLayout {
+            Rectangle {
+                height: 42px;
+//                      ^error{Cannot specify both 'height' and 'max-height'}
+                max-height: 12px;
+
+            }
+        }
+    }
+
 
 }