Avoid ICE on #![doc(test(...)] with literal parameter

Author: obeis

compiler/rustc_passes/messages.ftl

@@ -214,6 +214,8 @@ passes_doc_keyword_only_impl =
 passes_doc_test_takes_list =
     `#[doc(test(...)]` takes a list of attributes
 
+passes_doc_test_literal = `#![doc(test(...)]` does not take a literal
+
 passes_doc_test_unknown =
     unknown `doc(test)` attribute `{$path}`
 

compiler/rustc_passes/src/check_attr.rs

@@ -944,21 +944,28 @@ impl CheckAttrVisitor<'_> {
         let mut is_valid = true;
         if let Some(metas) = meta.meta_item_list() {
             for i_meta in metas {
-                match i_meta.name_or_empty() {
-                    sym::attr | sym::no_crate_inject => {}
-                    _ => {
+                match (i_meta.name_or_empty(), i_meta.meta_item()) {
+                    (sym::attr | sym::no_crate_inject, _) => {}
+                    (_, Some(m)) => {
                         self.tcx.emit_spanned_lint(
                             INVALID_DOC_ATTRIBUTES,
                             hir_id,
                             i_meta.span(),
                             errors::DocTestUnknown {
-                                path: rustc_ast_pretty::pprust::path_to_string(
-                                    &i_meta.meta_item().unwrap().path,
-                                ),
+                                path: rustc_ast_pretty::pprust::path_to_string(&m.path),
                             },
                         );
                         is_valid = false;
                     }
+                    (_, None) => {
+                        self.tcx.emit_spanned_lint(
+                            INVALID_DOC_ATTRIBUTES,
+                            hir_id,
+                            i_meta.span(),
+                            errors::DocTestLiteral,
+                        );
+                        is_valid = false;
+                    }
                 }
             }
         } else {

compiler/rustc_passes/src/errors.rs

@@ -281,6 +281,10 @@ pub struct DocTestUnknown {
     pub path: String,
 }
 
+#[derive(LintDiagnostic)]
+#[diag(passes_doc_test_literal)]
+pub struct DocTestLiteral;
+
 #[derive(LintDiagnostic)]
 #[diag(passes_doc_test_takes_list)]
 pub struct DocTestTakesList;