untranslatable_diagnostic lint: point at the untranslated thing

and not the function/method call

Author: GrigorenkoPV

compiler/rustc_lint/src/internal.rs

@@ -415,14 +415,17 @@ declare_lint_pass!(Diagnostics => [UNTRANSLATABLE_DIAGNOSTIC, DIAGNOSTIC_OUTSIDE
 
 impl LateLintPass<'_> for Diagnostics {
     fn check_expr(&mut self, cx: &LateContext<'_>, expr: &Expr<'_>) {
+        let collect_args_tys_and_spans = |args: &[Expr<'_>], reserve_one_extra: bool| {
+            let mut result = Vec::with_capacity(args.len() + usize::from(reserve_one_extra));
+            result.extend(args.iter().map(|arg| (cx.typeck_results().expr_ty(arg), arg.span)));
+            result
+        };
         // Only check function calls and method calls.
-        let (span, def_id, fn_gen_args, call_tys) = match expr.kind {
+        let (span, def_id, fn_gen_args, arg_tys_and_spans) = match expr.kind {
             ExprKind::Call(callee, args) => {
                 match cx.typeck_results().node_type(callee.hir_id).kind() {
                     &ty::FnDef(def_id, fn_gen_args) => {
-                        let call_tys: Vec<_> =
-                            args.iter().map(|arg| cx.typeck_results().expr_ty(arg)).collect();
-                        (callee.span, def_id, fn_gen_args, call_tys)
+                        (callee.span, def_id, fn_gen_args, collect_args_tys_and_spans(args, false))
                     }
                     _ => return, // occurs for fns passed as args
                 }
@@ -432,10 +435,9 @@ impl LateLintPass<'_> for Diagnostics {
                 else {
                     return;
                 };
-                let mut call_tys: Vec<_> =
-                    args.iter().map(|arg| cx.typeck_results().expr_ty(arg)).collect();
-                call_tys.insert(0, cx.tcx.types.self_param); // dummy inserted for `self`
-                (span, def_id, fn_gen_args, call_tys)
+                let mut args = collect_args_tys_and_spans(args, true);
+                args.insert(0, (cx.tcx.types.self_param, _recv.span)); // dummy inserted for `self`
+                (span, def_id, fn_gen_args, args)
             }
             _ => return,
         };
@@ -525,11 +527,11 @@ impl LateLintPass<'_> for Diagnostics {
         // `UNTRANSLATABLE_DIAGNOSTIC` lint.
         for (param_i, param_i_p_name) in impl_into_diagnostic_message_params {
             // Is the arg type `{Sub,D}iagMessage`or `impl Into<{Sub,D}iagMessage>`?
-            let arg_ty = call_tys[param_i];
+            let (arg_ty, arg_span) = arg_tys_and_spans[param_i];
             let is_translatable = is_diag_message(arg_ty)
                 || matches!(arg_ty.kind(), ty::Param(p) if p.name == param_i_p_name);
             if !is_translatable {
-                cx.emit_span_lint(UNTRANSLATABLE_DIAGNOSTIC, span, UntranslatableDiag);
+                cx.emit_span_lint(UNTRANSLATABLE_DIAGNOSTIC, arg_span, UntranslatableDiag);
             }
         }
     }

tests/ui-fulldeps/internal-lints/diagnostics.stderr

@@ -1,8 +1,8 @@
 error: diagnostics should be created using translatable messages
-  --> $DIR/diagnostics.rs:43:9
+  --> $DIR/diagnostics.rs:43:31
    |
 LL |         Diag::new(dcx, level, "untranslatable diagnostic")
-   |         ^^^^^^^^^
+   |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
 note: the lint level is defined here
   --> $DIR/diagnostics.rs:7:9
@@ -11,16 +11,16 @@ LL | #![deny(rustc::untranslatable_diagnostic)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: diagnostics should be created using translatable messages
-  --> $DIR/diagnostics.rs:64:14
+  --> $DIR/diagnostics.rs:64:19
    |
 LL |         diag.note("untranslatable diagnostic");
-   |              ^^^^
+   |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: diagnostics should be created using translatable messages
-  --> $DIR/diagnostics.rs:85:14
+  --> $DIR/diagnostics.rs:85:19
    |
 LL |         diag.note("untranslatable diagnostic");
-   |              ^^^^
+   |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: diagnostics should only be created in `Diagnostic`/`Subdiagnostic`/`LintDiagnostic` impls
   --> $DIR/diagnostics.rs:99:21
@@ -41,36 +41,34 @@ LL |     let _diag = dcx.struct_err("untranslatable diagnostic");
    |                     ^^^^^^^^^^
 
 error: diagnostics should be created using translatable messages
-  --> $DIR/diagnostics.rs:102:21
+  --> $DIR/diagnostics.rs:102:32
    |
 LL |     let _diag = dcx.struct_err("untranslatable diagnostic");
-   |                     ^^^^^^^^^^
+   |                                ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: diagnostics should be created using translatable messages
-  --> $DIR/diagnostics.rs:120:5
+  --> $DIR/diagnostics.rs:120:7
    |
 LL |     f("untranslatable diagnostic", crate::fluent_generated::no_crate_example);
-   |     ^
+   |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: diagnostics should be created using translatable messages
-  --> $DIR/diagnostics.rs:122:5
+  --> $DIR/diagnostics.rs:122:50
    |
 LL |     f(crate::fluent_generated::no_crate_example, "untranslatable diagnostic");
-   |     ^
+   |                                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: diagnostics should be created using translatable messages
-  --> $DIR/diagnostics.rs:124:5
+  --> $DIR/diagnostics.rs:124:7
    |
 LL |     f("untranslatable diagnostic", "untranslatable diagnostic");
-   |     ^
+   |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: diagnostics should be created using translatable messages
-  --> $DIR/diagnostics.rs:124:5
+  --> $DIR/diagnostics.rs:124:36
    |
 LL |     f("untranslatable diagnostic", "untranslatable diagnostic");
-   |     ^
-   |
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
+   |                                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: aborting due to 10 previous errors