Merge branch 'master' into add-disable-diagnostics

1 files changed, 644 insertions, 0 deletions

diff --git a/crates/ide/src/completion/complete_attribute.rs b/crates/ide/src/completion/complete_attribute.rs
new file mode 100644
index 000000000..603d935de
--- /dev/null
+++ b/crates/ide/src/completion/complete_attribute.rs
@@ -0,0 +1,644 @@
+//! Completion for attributes
+//!
+//! This module uses a bit of static metadata to provide completions
+//! for built-in attributes.
+
+use rustc_hash::FxHashSet;
+use syntax::{ast, AstNode, SyntaxKind};
+
+use crate::completion::{
+    completion_context::CompletionContext,
+    completion_item::{CompletionItem, CompletionItemKind, CompletionKind, Completions},
+};
+
+pub(super) fn complete_attribute(acc: &mut Completions, ctx: &CompletionContext) -> Option<()> {
+    let attribute = ctx.attribute_under_caret.as_ref()?;
+    match (attribute.path(), attribute.token_tree()) {
+        (Some(path), Some(token_tree)) if path.to_string() == "derive" => {
+            complete_derive(acc, ctx, token_tree)
+        }
+        (Some(path), Some(token_tree))
+            if ["allow", "warn", "deny", "forbid"]
+                .iter()
+                .any(|lint_level| lint_level == &path.to_string()) =>
+        {
+            complete_lint(acc, ctx, token_tree)
+        }
+        (_, Some(_token_tree)) => {}
+        _ => complete_attribute_start(acc, ctx, attribute),
+    }
+    Some(())
+}
+
+fn complete_attribute_start(acc: &mut Completions, ctx: &CompletionContext, attribute: &ast::Attr) {
+    for attr_completion in ATTRIBUTES {
+        let mut item = CompletionItem::new(
+            CompletionKind::Attribute,
+            ctx.source_range(),
+            attr_completion.label,
+        )
+        .kind(CompletionItemKind::Attribute);
+
+        if let Some(lookup) = attr_completion.lookup {
+            item = item.lookup_by(lookup);
+        }
+
+        match (attr_completion.snippet, ctx.config.snippet_cap) {
+            (Some(snippet), Some(cap)) => {
+                item = item.insert_snippet(cap, snippet);
+            }
+            _ => {}
+        }
+
+        if attribute.kind() == ast::AttrKind::Inner || !attr_completion.prefer_inner {
+            acc.add(item);
+        }
+    }
+}
+
+struct AttrCompletion {
+    label: &'static str,
+    lookup: Option<&'static str>,
+    snippet: Option<&'static str>,
+    prefer_inner: bool,
+}
+
+impl AttrCompletion {
+    const fn prefer_inner(self) -> AttrCompletion {
+        AttrCompletion { prefer_inner: true, ..self }
+    }
+}
+
+const fn attr(
+    label: &'static str,
+    lookup: Option<&'static str>,
+    snippet: Option<&'static str>,
+) -> AttrCompletion {
+    AttrCompletion { label, lookup, snippet, prefer_inner: false }
+}
+
+const ATTRIBUTES: &[AttrCompletion] = &[
+    attr("allow(…)", Some("allow"), Some("allow(${0:lint})")),
+    attr("cfg_attr(…)", Some("cfg_attr"), Some("cfg_attr(${1:predicate}, ${0:attr})")),
+    attr("cfg(…)", Some("cfg"), Some("cfg(${0:predicate})")),
+    attr("deny(…)", Some("deny"), Some("deny(${0:lint})")),
+    attr(r#"deprecated = "…""#, Some("deprecated"), Some(r#"deprecated = "${0:reason}""#)),
+    attr("derive(…)", Some("derive"), Some(r#"derive(${0:Debug})"#)),
+    attr(r#"doc = "…""#, Some("doc"), Some(r#"doc = "${0:docs}""#)),
+    attr("feature(…)", Some("feature"), Some("feature(${0:flag})")).prefer_inner(),
+    attr("forbid(…)", Some("forbid"), Some("forbid(${0:lint})")),
+    // FIXME: resolve through macro resolution?
+    attr("global_allocator", None, None).prefer_inner(),
+    attr(r#"ignore = "…""#, Some("ignore"), Some(r#"ignore = "${0:reason}""#)),
+    attr("inline(…)", Some("inline"), Some("inline(${0:lint})")),
+    attr(r#"link_name = "…""#, Some("link_name"), Some(r#"link_name = "${0:symbol_name}""#)),
+    attr("link", None, None),
+    attr("macro_export", None, None),
+    attr("macro_use", None, None),
+    attr(r#"must_use = "…""#, Some("must_use"), Some(r#"must_use = "${0:reason}""#)),
+    attr("no_mangle", None, None),
+    attr("no_std", None, None).prefer_inner(),
+    attr("non_exhaustive", None, None),
+    attr("panic_handler", None, None).prefer_inner(),
+    attr("path = \"…\"", Some("path"), Some("path =\"${0:path}\"")),
+    attr("proc_macro", None, None),
+    attr("proc_macro_attribute", None, None),
+    attr("proc_macro_derive(…)", Some("proc_macro_derive"), Some("proc_macro_derive(${0:Trait})")),
+    attr("recursion_limit = …", Some("recursion_limit"), Some("recursion_limit = ${0:128}"))
+        .prefer_inner(),
+    attr("repr(…)", Some("repr"), Some("repr(${0:C})")),
+    attr(
+        "should_panic(…)",
+        Some("should_panic"),
+        Some(r#"should_panic(expected = "${0:reason}")"#),
+    ),
+    attr(
+        r#"target_feature = "…""#,
+        Some("target_feature"),
+        Some("target_feature = \"${0:feature}\""),
+    ),
+    attr("test", None, None),
+    attr("used", None, None),
+    attr("warn(…)", Some("warn"), Some("warn(${0:lint})")),
+    attr(
+        r#"windows_subsystem = "…""#,
+        Some("windows_subsystem"),
+        Some(r#"windows_subsystem = "${0:subsystem}""#),
+    )
+    .prefer_inner(),
+];
+
+fn complete_derive(acc: &mut Completions, ctx: &CompletionContext, derive_input: ast::TokenTree) {
+    if let Ok(existing_derives) = parse_comma_sep_input(derive_input) {
+        for derive_completion in DEFAULT_DERIVE_COMPLETIONS
+            .into_iter()
+            .filter(|completion| !existing_derives.contains(completion.label))
+        {
+            let mut label = derive_completion.label.to_owned();
+            for dependency in derive_completion
+                .dependencies
+                .into_iter()
+                .filter(|&&dependency| !existing_derives.contains(dependency))
+            {
+                label.push_str(", ");
+                label.push_str(dependency);
+            }
+            acc.add(
+                CompletionItem::new(CompletionKind::Attribute, ctx.source_range(), label)
+                    .kind(CompletionItemKind::Attribute),
+            );
+        }
+
+        for custom_derive_name in get_derive_names_in_scope(ctx).difference(&existing_derives) {
+            acc.add(
+                CompletionItem::new(
+                    CompletionKind::Attribute,
+                    ctx.source_range(),
+                    custom_derive_name,
+                )
+                .kind(CompletionItemKind::Attribute),
+            );
+        }
+    }
+}
+
+fn complete_lint(acc: &mut Completions, ctx: &CompletionContext, derive_input: ast::TokenTree) {
+    if let Ok(existing_lints) = parse_comma_sep_input(derive_input) {
+        for lint_completion in DEFAULT_LINT_COMPLETIONS
+            .into_iter()
+            .filter(|completion| !existing_lints.contains(completion.label))
+        {
+            acc.add(
+                CompletionItem::new(
+                    CompletionKind::Attribute,
+                    ctx.source_range(),
+                    lint_completion.label,
+                )
+                .kind(CompletionItemKind::Attribute)
+                .detail(lint_completion.description),
+            );
+        }
+    }
+}
+
+fn parse_comma_sep_input(derive_input: ast::TokenTree) -> Result<FxHashSet<String>, ()> {
+    match (derive_input.left_delimiter_token(), derive_input.right_delimiter_token()) {
+        (Some(left_paren), Some(right_paren))
+            if left_paren.kind() == SyntaxKind::L_PAREN
+                && right_paren.kind() == SyntaxKind::R_PAREN =>
+        {
+            let mut input_derives = FxHashSet::default();
+            let mut current_derive = String::new();
+            for token in derive_input
+                .syntax()
+                .children_with_tokens()
+                .filter_map(|token| token.into_token())
+                .skip_while(|token| token != &left_paren)
+                .skip(1)
+                .take_while(|token| token != &right_paren)
+            {
+                if SyntaxKind::COMMA == token.kind() {
+                    if !current_derive.is_empty() {
+                        input_derives.insert(current_derive);
+                        current_derive = String::new();
+                    }
+                } else {
+                    current_derive.push_str(token.to_string().trim());
+                }
+            }
+
+            if !current_derive.is_empty() {
+                input_derives.insert(current_derive);
+            }
+            Ok(input_derives)
+        }
+        _ => Err(()),
+    }
+}
+
+fn get_derive_names_in_scope(ctx: &CompletionContext) -> FxHashSet<String> {
+    let mut result = FxHashSet::default();
+    ctx.scope.process_all_names(&mut |name, scope_def| {
+        if let hir::ScopeDef::MacroDef(mac) = scope_def {
+            if mac.is_derive_macro() {
+                result.insert(name.to_string());
+            }
+        }
+    });
+    result
+}
+
+struct DeriveCompletion {
+    label: &'static str,
+    dependencies: &'static [&'static str],
+}
+
+/// Standard Rust derives and the information about their dependencies
+/// (the dependencies are needed so that the main derive don't break the compilation when added)
+#[rustfmt::skip]
+const DEFAULT_DERIVE_COMPLETIONS: &[DeriveCompletion] = &[
+    DeriveCompletion { label: "Clone", dependencies: &[] },
+    DeriveCompletion { label: "Copy", dependencies: &["Clone"] },
+    DeriveCompletion { label: "Debug", dependencies: &[] },
+    DeriveCompletion { label: "Default", dependencies: &[] },
+    DeriveCompletion { label: "Hash", dependencies: &[] },
+    DeriveCompletion { label: "PartialEq", dependencies: &[] },
+    DeriveCompletion { label: "Eq", dependencies: &["PartialEq"] },
+    DeriveCompletion { label: "PartialOrd", dependencies: &["PartialEq"] },
+    DeriveCompletion { label: "Ord", dependencies: &["PartialOrd", "Eq", "PartialEq"] },
+];
+
+struct LintCompletion {
+    label: &'static str,
+    description: &'static str,
+}
+
+#[rustfmt::skip]
+const DEFAULT_LINT_COMPLETIONS: &[LintCompletion] = &[
+    LintCompletion { label: "absolute_paths_not_starting_with_crate", description: r#"fully qualified paths that start with a module name instead of `crate`, `self`, or an extern crate name"# },
+    LintCompletion { label: "anonymous_parameters", description: r#"detects anonymous parameters"# },
+    LintCompletion { label: "box_pointers", description: r#"use of owned (Box type) heap memory"# },
+    LintCompletion { label: "deprecated_in_future", description: r#"detects use of items that will be deprecated in a future version"# },
+    LintCompletion { label: "elided_lifetimes_in_paths", description: r#"hidden lifetime parameters in types are deprecated"# },
+    LintCompletion { label: "explicit_outlives_requirements", description: r#"outlives requirements can be inferred"# },
+    LintCompletion { label: "indirect_structural_match", description: r#"pattern with const indirectly referencing non-structural-match type"# },
+    LintCompletion { label: "keyword_idents", description: r#"detects edition keywords being used as an identifier"# },
+    LintCompletion { label: "macro_use_extern_crate", description: r#"the `#[macro_use]` attribute is now deprecated in favor of using macros via the module system"# },
+    LintCompletion { label: "meta_variable_misuse", description: r#"possible meta-variable misuse at macro definition"# },
+    LintCompletion { label: "missing_copy_implementations", description: r#"detects potentially-forgotten implementations of `Copy`"# },
+    LintCompletion { label: "missing_crate_level_docs", description: r#"detects crates with no crate-level documentation"# },
+    LintCompletion { label: "missing_debug_implementations", description: r#"detects missing implementations of Debug"# },
+    LintCompletion { label: "missing_docs", description: r#"detects missing documentation for public members"# },
+    LintCompletion { label: "missing_doc_code_examples", description: r#"detects publicly-exported items without code samples in their documentation"# },
+    LintCompletion { label: "non_ascii_idents", description: r#"detects non-ASCII identifiers"# },
+    LintCompletion { label: "private_doc_tests", description: r#"detects code samples in docs of private items not documented by rustdoc"# },
+    LintCompletion { label: "single_use_lifetimes", description: r#"detects lifetime parameters that are only used once"# },
+    LintCompletion { label: "trivial_casts", description: r#"detects trivial casts which could be removed"# },
+    LintCompletion { label: "trivial_numeric_casts", description: r#"detects trivial casts of numeric types which could be removed"# },
+    LintCompletion { label: "unaligned_references", description: r#"detects unaligned references to fields of packed structs"# },
+    LintCompletion { label: "unreachable_pub", description: r#"`pub` items not reachable from crate root"# },
+    LintCompletion { label: "unsafe_code", description: r#"usage of `unsafe` code"# },
+    LintCompletion { label: "unsafe_op_in_unsafe_fn", description: r#"unsafe operations in unsafe functions without an explicit unsafe block are deprecated"# },
+    LintCompletion { label: "unstable_features", description: r#"enabling unstable features (deprecated. do not use)"# },
+    LintCompletion { label: "unused_crate_dependencies", description: r#"crate dependencies that are never used"# },
+    LintCompletion { label: "unused_extern_crates", description: r#"extern crates that are never used"# },
+    LintCompletion { label: "unused_import_braces", description: r#"unnecessary braces around an imported item"# },
+    LintCompletion { label: "unused_lifetimes", description: r#"detects lifetime parameters that are never used"# },
+    LintCompletion { label: "unused_qualifications", description: r#"detects unnecessarily qualified names"# },
+    LintCompletion { label: "unused_results", description: r#"unused result of an expression in a statement"# },
+    LintCompletion { label: "variant_size_differences", description: r#"detects enums with widely varying variant sizes"# },
+    LintCompletion { label: "array_into_iter", description: r#"detects calling `into_iter` on arrays"# },
+    LintCompletion { label: "asm_sub_register", description: r#"using only a subset of a register for inline asm inputs"# },
+    LintCompletion { label: "bare_trait_objects", description: r#"suggest using `dyn Trait` for trait objects"# },
+    LintCompletion { label: "bindings_with_variant_name", description: r#"detects pattern bindings with the same name as one of the matched variants"# },
+    LintCompletion { label: "cenum_impl_drop_cast", description: r#"a C-like enum implementing Drop is cast"# },
+    LintCompletion { label: "clashing_extern_declarations", description: r#"detects when an extern fn has been declared with the same name but different types"# },
+    LintCompletion { label: "coherence_leak_check", description: r#"distinct impls distinguished only by the leak-check code"# },
+    LintCompletion { label: "confusable_idents", description: r#"detects visually confusable pairs between identifiers"# },
+    LintCompletion { label: "dead_code", description: r#"detect unused, unexported items"# },
+    LintCompletion { label: "deprecated", description: r#"detects use of deprecated items"# },
+    LintCompletion { label: "ellipsis_inclusive_range_patterns", description: r#"`...` range patterns are deprecated"# },
+    LintCompletion { label: "exported_private_dependencies", description: r#"public interface leaks type from a private dependency"# },
+    LintCompletion { label: "illegal_floating_point_literal_pattern", description: r#"floating-point literals cannot be used in patterns"# },
+    LintCompletion { label: "improper_ctypes", description: r#"proper use of libc types in foreign modules"# },
+    LintCompletion { label: "improper_ctypes_definitions", description: r#"proper use of libc types in foreign item definitions"# },
+    LintCompletion { label: "incomplete_features", description: r#"incomplete features that may function improperly in some or all cases"# },
+    LintCompletion { label: "inline_no_sanitize", description: r#"detects incompatible use of `#[inline(always)]` and `#[no_sanitize(...)]`"# },
+    LintCompletion { label: "intra_doc_link_resolution_failure", description: r#"failures in resolving intra-doc link targets"# },
+    LintCompletion { label: "invalid_codeblock_attributes", description: r#"codeblock attribute looks a lot like a known one"# },
+    LintCompletion { label: "invalid_value", description: r#"an invalid value is being created (such as a NULL reference)"# },
+    LintCompletion { label: "irrefutable_let_patterns", description: r#"detects irrefutable patterns in if-let and while-let statements"# },
+    LintCompletion { label: "late_bound_lifetime_arguments", description: r#"detects generic lifetime arguments in path segments with late bound lifetime parameters"# },
+    LintCompletion { label: "mixed_script_confusables", description: r#"detects Unicode scripts whose mixed script confusables codepoints are solely used"# },
+    LintCompletion { label: "mutable_borrow_reservation_conflict", description: r#"reservation of a two-phased borrow conflicts with other shared borrows"# },
+    LintCompletion { label: "non_camel_case_types", description: r#"types, variants, traits and type parameters should have camel case names"# },
+    LintCompletion { label: "non_shorthand_field_patterns", description: r#"using `Struct { x: x }` instead of `Struct { x }` in a pattern"# },
+    LintCompletion { label: "non_snake_case", description: r#"variables, methods, functions, lifetime parameters and modules should have snake case names"# },
+    LintCompletion { label: "non_upper_case_globals", description: r#"static constants should have uppercase identifiers"# },
+    LintCompletion { label: "no_mangle_generic_items", description: r#"generic items must be mangled"# },
+    LintCompletion { label: "overlapping_patterns", description: r#"detects overlapping patterns"# },
+    LintCompletion { label: "path_statements", description: r#"path statements with no effect"# },
+    LintCompletion { label: "private_in_public", description: r#"detect private items in public interfaces not caught by the old implementation"# },
+    LintCompletion { label: "proc_macro_derive_resolution_fallback", description: r#"detects proc macro derives using inaccessible names from parent modules"# },
+    LintCompletion { label: "redundant_semicolons", description: r#"detects unnecessary trailing semicolons"# },
+    LintCompletion { label: "renamed_and_removed_lints", description: r#"lints that have been renamed or removed"# },
+    LintCompletion { label: "safe_packed_borrows", description: r#"safe borrows of fields of packed structs were erroneously allowed"# },
+    LintCompletion { label: "stable_features", description: r#"stable features found in `#[feature]` directive"# },
+    LintCompletion { label: "trivial_bounds", description: r#"these bounds don't depend on an type parameters"# },
+    LintCompletion { label: "type_alias_bounds", description: r#"bounds in type aliases are not enforced"# },
+    LintCompletion { label: "tyvar_behind_raw_pointer", description: r#"raw pointer to an inference variable"# },
+    LintCompletion { label: "uncommon_codepoints", description: r#"detects uncommon Unicode codepoints in identifiers"# },
+    LintCompletion { label: "unconditional_recursion", description: r#"functions that cannot return without calling themselves"# },
+    LintCompletion { label: "unknown_lints", description: r#"unrecognized lint attribute"# },
+    LintCompletion { label: "unnameable_test_items", description: r#"detects an item that cannot be named being marked as `#[test_case]`"# },
+    LintCompletion { label: "unreachable_code", description: r#"detects unreachable code paths"# },
+    LintCompletion { label: "unreachable_patterns", description: r#"detects unreachable patterns"# },
+    LintCompletion { label: "unstable_name_collisions", description: r#"detects name collision with an existing but unstable method"# },
+    LintCompletion { label: "unused_allocation", description: r#"detects unnecessary allocations that can be eliminated"# },
+    LintCompletion { label: "unused_assignments", description: r#"detect assignments that will never be read"# },
+    LintCompletion { label: "unused_attributes", description: r#"detects attributes that were not used by the compiler"# },
+    LintCompletion { label: "unused_braces", description: r#"unnecessary braces around an expression"# },
+    LintCompletion { label: "unused_comparisons", description: r#"comparisons made useless by limits of the types involved"# },
+    LintCompletion { label: "unused_doc_comments", description: r#"detects doc comments that aren't used by rustdoc"# },
+    LintCompletion { label: "unused_features", description: r#"unused features found in crate-level `#[feature]` directives"# },
+    LintCompletion { label: "unused_imports", description: r#"imports that are never used"# },
+    LintCompletion { label: "unused_labels", description: r#"detects labels that are never used"# },
+    LintCompletion { label: "unused_macros", description: r#"detects macros that were not used"# },
+    LintCompletion { label: "unused_must_use", description: r#"unused result of a type flagged as `#[must_use]`"# },
+    LintCompletion { label: "unused_mut", description: r#"detect mut variables which don't need to be mutable"# },
+    LintCompletion { label: "unused_parens", description: r#"`if`, `match`, `while` and `return` do not need parentheses"# },
+    LintCompletion { label: "unused_unsafe", description: r#"unnecessary use of an `unsafe` block"# },
+    LintCompletion { label: "unused_variables", description: r#"detect variables which are not used in any way"# },
+    LintCompletion { label: "warnings", description: r#"mass-change the level for lints which produce warnings"# },
+    LintCompletion { label: "where_clauses_object_safety", description: r#"checks the object safety of where clauses"# },
+    LintCompletion { label: "while_true", description: r#"suggest using `loop { }` instead of `while true { }`"# },
+    LintCompletion { label: "ambiguous_associated_items", description: r#"ambiguous associated items"# },
+    LintCompletion { label: "arithmetic_overflow", description: r#"arithmetic operation overflows"# },
+    LintCompletion { label: "conflicting_repr_hints", description: r#"conflicts between `#[repr(..)]` hints that were previously accepted and used in practice"# },
+    LintCompletion { label: "const_err", description: r#"constant evaluation detected erroneous expression"# },
+    LintCompletion { label: "ill_formed_attribute_input", description: r#"ill-formed attribute inputs that were previously accepted and used in practice"# },
+    LintCompletion { label: "incomplete_include", description: r#"trailing content in included file"# },
+    LintCompletion { label: "invalid_type_param_default", description: r#"type parameter default erroneously allowed in invalid location"# },
+    LintCompletion { label: "macro_expanded_macro_exports_accessed_by_absolute_paths", description: r#"macro-expanded `macro_export` macros from the current crate cannot be referred to by absolute paths"# },
+    LintCompletion { label: "missing_fragment_specifier", description: r#"detects missing fragment specifiers in unused `macro_rules!` patterns"# },
+    LintCompletion { label: "mutable_transmutes", description: r#"mutating transmuted &mut T from &T may cause undefined behavior"# },
+    LintCompletion { label: "no_mangle_const_items", description: r#"const items will not have their symbols exported"# },
+    LintCompletion { label: "order_dependent_trait_objects", description: r#"trait-object types were treated as different depending on marker-trait order"# },
+    LintCompletion { label: "overflowing_literals", description: r#"literal out of range for its type"# },
+    LintCompletion { label: "patterns_in_fns_without_body", description: r#"patterns in functions without body were erroneously allowed"# },
+    LintCompletion { label: "pub_use_of_private_extern_crate", description: r#"detect public re-exports of private extern crates"# },
+    LintCompletion { label: "soft_unstable", description: r#"a feature gate that doesn't break dependent crates"# },
+    LintCompletion { label: "unconditional_panic", description: r#"operation will cause a panic at runtime"# },
+    LintCompletion { label: "unknown_crate_types", description: r#"unknown crate type found in `#[crate_type]` directive"# },
+];
+
+#[cfg(test)]
+mod tests {
+    use expect::{expect, Expect};
+
+    use crate::completion::{test_utils::completion_list, CompletionKind};
+
+    fn check(ra_fixture: &str, expect: Expect) {
+        let actual = completion_list(ra_fixture, CompletionKind::Attribute);
+        expect.assert_eq(&actual);
+    }
+
+    #[test]
+    fn empty_derive_completion() {
+        check(
+            r#"
+#[derive(<|>)]
+struct Test {}
+        "#,
+            expect![[r#"
+                at Clone
+                at Copy, Clone
+                at Debug
+                at Default
+                at Eq, PartialEq
+                at Hash
+                at Ord, PartialOrd, Eq, PartialEq
+                at PartialEq
+                at PartialOrd, PartialEq
+            "#]],
+        );
+    }
+
+    #[test]
+    fn empty_lint_completion() {
+        check(
+            r#"#[allow(<|>)]"#,
+            expect![[r#"
+                at absolute_paths_not_starting_with_crate fully qualified paths that start with a module name instead of `crate`, `self`, or an extern crate name
+                at ambiguous_associated_items ambiguous associated items
+                at anonymous_parameters detects anonymous parameters
+                at arithmetic_overflow arithmetic operation overflows
+                at array_into_iter  detects calling `into_iter` on arrays
+                at asm_sub_register using only a subset of a register for inline asm inputs
+                at bare_trait_objects suggest using `dyn Trait` for trait objects
+                at bindings_with_variant_name detects pattern bindings with the same name as one of the matched variants
+                at box_pointers     use of owned (Box type) heap memory
+                at cenum_impl_drop_cast a C-like enum implementing Drop is cast
+                at clashing_extern_declarations detects when an extern fn has been declared with the same name but different types
+                at coherence_leak_check distinct impls distinguished only by the leak-check code
+                at conflicting_repr_hints conflicts between `#[repr(..)]` hints that were previously accepted and used in practice
+                at confusable_idents detects visually confusable pairs between identifiers
+                at const_err        constant evaluation detected erroneous expression
+                at dead_code        detect unused, unexported items
+                at deprecated       detects use of deprecated items
+                at deprecated_in_future detects use of items that will be deprecated in a future version
+                at elided_lifetimes_in_paths hidden lifetime parameters in types are deprecated
+                at ellipsis_inclusive_range_patterns `...` range patterns are deprecated
+                at explicit_outlives_requirements outlives requirements can be inferred
+                at exported_private_dependencies public interface leaks type from a private dependency
+                at ill_formed_attribute_input ill-formed attribute inputs that were previously accepted and used in practice
+                at illegal_floating_point_literal_pattern floating-point literals cannot be used in patterns
+                at improper_ctypes  proper use of libc types in foreign modules
+                at improper_ctypes_definitions proper use of libc types in foreign item definitions
+                at incomplete_features incomplete features that may function improperly in some or all cases
+                at incomplete_include trailing content in included file
+                at indirect_structural_match pattern with const indirectly referencing non-structural-match type
+                at inline_no_sanitize detects incompatible use of `#[inline(always)]` and `#[no_sanitize(...)]`
+                at intra_doc_link_resolution_failure failures in resolving intra-doc link targets
+                at invalid_codeblock_attributes codeblock attribute looks a lot like a known one
+                at invalid_type_param_default type parameter default erroneously allowed in invalid location
+                at invalid_value    an invalid value is being created (such as a NULL reference)
+                at irrefutable_let_patterns detects irrefutable patterns in if-let and while-let statements
+                at keyword_idents   detects edition keywords being used as an identifier
+                at late_bound_lifetime_arguments detects generic lifetime arguments in path segments with late bound lifetime parameters
+                at macro_expanded_macro_exports_accessed_by_absolute_paths macro-expanded `macro_export` macros from the current crate cannot be referred to by absolute paths
+                at macro_use_extern_crate the `#[macro_use]` attribute is now deprecated in favor of using macros via the module system
+                at meta_variable_misuse possible meta-variable misuse at macro definition
+                at missing_copy_implementations detects potentially-forgotten implementations of `Copy`
+                at missing_crate_level_docs detects crates with no crate-level documentation
+                at missing_debug_implementations detects missing implementations of Debug
+                at missing_doc_code_examples detects publicly-exported items without code samples in their documentation
+                at missing_docs     detects missing documentation for public members
+                at missing_fragment_specifier detects missing fragment specifiers in unused `macro_rules!` patterns
+                at mixed_script_confusables detects Unicode scripts whose mixed script confusables codepoints are solely used
+                at mutable_borrow_reservation_conflict reservation of a two-phased borrow conflicts with other shared borrows
+                at mutable_transmutes mutating transmuted &mut T from &T may cause undefined behavior
+                at no_mangle_const_items const items will not have their symbols exported
+                at no_mangle_generic_items generic items must be mangled
+                at non_ascii_idents detects non-ASCII identifiers
+                at non_camel_case_types types, variants, traits and type parameters should have camel case names
+                at non_shorthand_field_patterns using `Struct { x: x }` instead of `Struct { x }` in a pattern
+                at non_snake_case   variables, methods, functions, lifetime parameters and modules should have snake case names
+                at non_upper_case_globals static constants should have uppercase identifiers
+                at order_dependent_trait_objects trait-object types were treated as different depending on marker-trait order
+                at overflowing_literals literal out of range for its type
+                at overlapping_patterns detects overlapping patterns
+                at path_statements  path statements with no effect
+                at patterns_in_fns_without_body patterns in functions without body were erroneously allowed
+                at private_doc_tests detects code samples in docs of private items not documented by rustdoc
+                at private_in_public detect private items in public interfaces not caught by the old implementation
+                at proc_macro_derive_resolution_fallback detects proc macro derives using inaccessible names from parent modules
+                at pub_use_of_private_extern_crate detect public re-exports of private extern crates
+                at redundant_semicolons detects unnecessary trailing semicolons
+                at renamed_and_removed_lints lints that have been renamed or removed
+                at safe_packed_borrows safe borrows of fields of packed structs were erroneously allowed
+                at single_use_lifetimes detects lifetime parameters that are only used once
+                at soft_unstable    a feature gate that doesn't break dependent crates
+                at stable_features  stable features found in `#[feature]` directive
+                at trivial_bounds   these bounds don't depend on an type parameters
+                at trivial_casts    detects trivial casts which could be removed
+                at trivial_numeric_casts detects trivial casts of numeric types which could be removed
+                at type_alias_bounds bounds in type aliases are not enforced
+                at tyvar_behind_raw_pointer raw pointer to an inference variable
+                at unaligned_references detects unaligned references to fields of packed structs
+                at uncommon_codepoints detects uncommon Unicode codepoints in identifiers
+                at unconditional_panic operation will cause a panic at runtime
+                at unconditional_recursion functions that cannot return without calling themselves
+                at unknown_crate_types unknown crate type found in `#[crate_type]` directive
+                at unknown_lints    unrecognized lint attribute
+                at unnameable_test_items detects an item that cannot be named being marked as `#[test_case]`
+                at unreachable_code detects unreachable code paths
+                at unreachable_patterns detects unreachable patterns
+                at unreachable_pub  `pub` items not reachable from crate root
+                at unsafe_code      usage of `unsafe` code
+                at unsafe_op_in_unsafe_fn unsafe operations in unsafe functions without an explicit unsafe block are deprecated
+                at unstable_features enabling unstable features (deprecated. do not use)
+                at unstable_name_collisions detects name collision with an existing but unstable method
+                at unused_allocation detects unnecessary allocations that can be eliminated
+                at unused_assignments detect assignments that will never be read
+                at unused_attributes detects attributes that were not used by the compiler
+                at unused_braces    unnecessary braces around an expression
+                at unused_comparisons comparisons made useless by limits of the types involved
+                at unused_crate_dependencies crate dependencies that are never used
+                at unused_doc_comments detects doc comments that aren't used by rustdoc
+                at unused_extern_crates extern crates that are never used
+                at unused_features  unused features found in crate-level `#[feature]` directives
+                at unused_import_braces unnecessary braces around an imported item
+                at unused_imports   imports that are never used
+                at unused_labels    detects labels that are never used
+                at unused_lifetimes detects lifetime parameters that are never used
+                at unused_macros    detects macros that were not used
+                at unused_must_use  unused result of a type flagged as `#[must_use]`
+                at unused_mut       detect mut variables which don't need to be mutable
+                at unused_parens    `if`, `match`, `while` and `return` do not need parentheses
+                at unused_qualifications detects unnecessarily qualified names
+                at unused_results   unused result of an expression in a statement
+                at unused_unsafe    unnecessary use of an `unsafe` block
+                at unused_variables detect variables which are not used in any way
+                at variant_size_differences detects enums with widely varying variant sizes
+                at warnings         mass-change the level for lints which produce warnings
+                at where_clauses_object_safety checks the object safety of where clauses
+                at while_true       suggest using `loop { }` instead of `while true { }`
+        "#]],
+        )
+    }
+
+    #[test]
+    fn no_completion_for_incorrect_derive() {
+        check(
+            r#"
+#[derive{<|>)]
+struct Test {}
+"#,
+            expect![[r#""#]],
+        )
+    }
+
+    #[test]
+    fn derive_with_input_completion() {
+        check(
+            r#"
+#[derive(serde::Serialize, PartialEq, <|>)]
+struct Test {}
+"#,
+            expect![[r#"
+                at Clone
+                at Copy, Clone
+                at Debug
+                at Default
+                at Eq
+                at Hash
+                at Ord, PartialOrd, Eq
+                at PartialOrd
+            "#]],
+        )
+    }
+
+    #[test]
+    fn test_attribute_completion() {
+        check(
+            r#"#[<|>]"#,
+            expect![[r#"
+                at allow(…)
+                at cfg(…)
+                at cfg_attr(…)
+                at deny(…)
+                at deprecated = "…"
+                at derive(…)
+                at doc = "…"
+                at forbid(…)
+                at ignore = "…"
+                at inline(…)
+                at link
+                at link_name = "…"
+                at macro_export
+                at macro_use
+                at must_use = "…"
+                at no_mangle
+                at non_exhaustive
+                at path = "…"
+                at proc_macro
+                at proc_macro_attribute
+                at proc_macro_derive(…)
+                at repr(…)
+                at should_panic(…)
+                at target_feature = "…"
+                at test
+                at used
+                at warn(…)
+            "#]],
+        )
+    }
+
+    #[test]
+    fn test_attribute_completion_inside_nested_attr() {
+        check(r#"#[cfg(<|>)]"#, expect![[]])
+    }
+
+    #[test]
+    fn test_inner_attribute_completion() {
+        check(
+            r"#![<|>]",
+            expect![[r#"
+                at allow(…)
+                at cfg(…)
+                at cfg_attr(…)
+                at deny(…)
+                at deprecated = "…"
+                at derive(…)
+                at doc = "…"
+                at feature(…)
+                at forbid(…)
+                at global_allocator
+                at ignore = "…"
+                at inline(…)
+                at link
+                at link_name = "…"
+                at macro_export
+                at macro_use
+                at must_use = "…"
+                at no_mangle
+                at no_std
+                at non_exhaustive
+                at panic_handler
+                at path = "…"
+                at proc_macro
+                at proc_macro_attribute
+                at proc_macro_derive(…)
+                at recursion_limit = …
+                at repr(…)
+                at should_panic(…)
+                at target_feature = "…"
+                at test
+                at used
+                at warn(…)
+                at windows_subsystem = "…"
+            "#]],
+        );
+    }
+}