bundled translation: Better error reporting

forward the error up the stack instead of panicking while producing the llr

api/rs/build/lib.rs

@@ -459,7 +459,8 @@ pub fn compile_with_output(
     let output_file =
         std::fs::File::create(&output_rust_file_path).map_err(CompileError::SaveError)?;
     let mut code_formatter = CodeFormatter::new(BufWriter::new(output_file));
-    let generated = i_slint_compiler::generator::rust::generate(&doc, &loader.compiler_config);
+    let generated = i_slint_compiler::generator::rust::generate(&doc, &loader.compiler_config)
+        .map_err(|e| CompileError::CompileError(vec![e.to_string()]))?;
 
     let mut dependencies: Vec<std::path::PathBuf> = Vec::new();
 

api/rs/macros/lib.rs

@@ -415,7 +415,11 @@ pub fn slint(stream: TokenStream) -> TokenStream {
         return diag.report_macro_diagnostic(&tokens);
     }
 
-    let mut result = generator::rust::generate(&root_component, &loader.compiler_config);
+    let mut result = generator::rust::generate(&root_component, &loader.compiler_config)
+        .unwrap_or_else(|e| {
+            let e_str = e.to_string();
+            quote!(compile_error!(#e_str))
+        });
 
     // Make sure to recompile if any of the external files changes
     let reload = diag

internal/compiler/generator.rs

@@ -80,7 +80,7 @@ pub fn generate(
         }
         #[cfg(feature = "rust")]
         OutputFormat::Rust => {
-            let output = rust::generate(doc, compiler_config);
+            let output = rust::generate(doc, compiler_config)?;
             write!(destination, "{}", output)?;
         }
         OutputFormat::Interpreter => {
@@ -90,7 +90,7 @@ pub fn generate(
             )); // Perhaps byte code in the future?
         }
         OutputFormat::Llr => {
-            let root = crate::llr::lower_to_item_tree::lower_to_item_tree(doc, compiler_config);
+            let root = crate::llr::lower_to_item_tree::lower_to_item_tree(doc, compiler_config)?;
             let mut output = String::new();
             crate::llr::pretty_print::pretty_print(&root, &mut output).unwrap();
             write!(destination, "{output}")?;

internal/compiler/generator/cpp.rs

@@ -708,7 +708,7 @@ pub fn generate(
         }
     }
 
-    let llr = llr::lower_to_item_tree::lower_to_item_tree(&doc, compiler_config);
+    let llr = llr::lower_to_item_tree::lower_to_item_tree(&doc, compiler_config)?;
 
     #[cfg(feature = "bundle-translations")]
     if let Some(translations) = &llr.translations {

internal/compiler/generator/rust.rs

@@ -151,7 +151,10 @@ fn set_primitive_property_value(ty: &Type, value_expression: TokenStream) -> Tok
 }
 
 /// Generate the rust code for the given component.
-pub fn generate(doc: &Document, compiler_config: &CompilerConfiguration) -> TokenStream {
+pub fn generate(
+    doc: &Document,
+    compiler_config: &CompilerConfiguration,
+) -> std::io::Result<TokenStream> {
     let (structs_and_enums_ids, structs_and_enum_def): (Vec<_>, Vec<_>) = doc
         .used_types
         .borrow()
@@ -169,10 +172,10 @@ pub fn generate(doc: &Document, compiler_config: &CompilerConfiguration) -> Toke
         })
         .unzip();
 
-    let llr = crate::llr::lower_to_item_tree::lower_to_item_tree(doc, compiler_config);
+    let llr = crate::llr::lower_to_item_tree::lower_to_item_tree(doc, compiler_config)?;
 
     if llr.public_components.is_empty() {
-        return Default::default();
+        return Ok(Default::default());
     }
 
     let sub_compos = llr
@@ -215,7 +218,7 @@ pub fn generate(doc: &Document, compiler_config: &CompilerConfiguration) -> Toke
     #[cfg(feature = "bundle-translations")]
     let translations = llr.translations.as_ref().map(|t| (generate_translations(t, &llr)));
 
-    quote! {
+    Ok(quote! {
         #[allow(non_snake_case, non_camel_case_types)]
         #[allow(unused_braces, unused_parens)]
         #[allow(clippy::all)]
@@ -236,7 +239,7 @@ pub fn generate(doc: &Document, compiler_config: &CompilerConfiguration) -> Toke
         pub use #generated_mod::{#(#compo_ids,)* #(#structs_and_enums_ids,)* #(#globals_ids,)* #(#named_exports,)*};
         #[allow(unused_imports)]
         pub use slint::{ComponentHandle as _, Global as _, ModelExt as _};
-    }
+    })
 }
 
 fn generate_public_component(

internal/compiler/llr/lower_to_item_tree.rs

@@ -17,7 +17,7 @@ use std::rc::Rc;
 pub fn lower_to_item_tree(
     document: &crate::object_tree::Document,
     compiler_config: &CompilerConfiguration,
-) -> CompilationUnit {
+) -> std::io::Result<CompilationUnit> {
     let mut state = LoweringState::default();
 
     #[cfg(feature = "bundle-translations")]
@@ -27,7 +27,7 @@ pub fn lower_to_item_tree(
                 path,
                 compiler_config.translation_domain.as_deref().unwrap_or(""),
             )
-            .unwrap_or_else(|e| todo!("TODO: handle error loading translations: {e}")),
+            .map_err(|e| std::io::Error::other(format!("Cannot load bundled translation: {e}")))?,
         ));
     }
 
@@ -79,7 +79,7 @@ pub fn lower_to_item_tree(
         translations: state.translation_builder.take().map(|x| x.into_inner().result()),
     };
     super::optim_passes::run_passes(&root);
-    root
+    Ok(root)
 }
 
 #[derive(Default)]