Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/ide-completion/src/completions/attribute.rs')
| -rw-r--r-- | crates/ide-completion/src/completions/attribute.rs | 372 |
1 files changed, 372 insertions, 0 deletions
diff --git a/crates/ide-completion/src/completions/attribute.rs b/crates/ide-completion/src/completions/attribute.rs new file mode 100644 index 0000000000..09ba672a14 --- /dev/null +++ b/crates/ide-completion/src/completions/attribute.rs @@ -0,0 +1,372 @@ +//! Completion for (built-in) attributes, derives and lints. +//! +//! This module uses a bit of static metadata to provide completions for builtin-in attributes and lints. + +use ide_db::{ + generated::lints::{ + Lint, CLIPPY_LINTS, CLIPPY_LINT_GROUPS, DEFAULT_LINTS, FEATURES, RUSTDOC_LINTS, + }, + syntax_helpers::node_ext::parse_tt_as_comma_sep_paths, + FxHashMap, SymbolKind, +}; +use itertools::Itertools; +use once_cell::sync::Lazy; +use syntax::{ + ast::{self, AttrKind}, + AstNode, SyntaxKind, T, +}; + +use crate::{ + completions::module_or_attr, + context::{CompletionContext, PathCompletionCtx, PathKind, PathQualifierCtx}, + item::CompletionItem, + Completions, +}; + +mod cfg; +mod derive; +mod lint; +mod repr; + +pub(crate) use self::derive::complete_derive; + +/// Complete inputs to known builtin attributes as well as derive attributes +pub(crate) fn complete_known_attribute_input( + acc: &mut Completions, + ctx: &CompletionContext, +) -> Option<()> { + let attribute = ctx.fake_attribute_under_caret.as_ref()?; + let name_ref = match attribute.path() { + Some(p) => Some(p.as_single_name_ref()?), + None => None, + }; + let (path, tt) = name_ref.zip(attribute.token_tree())?; + if tt.l_paren_token().is_none() { + return None; + } + + match path.text().as_str() { + "repr" => repr::complete_repr(acc, ctx, tt), + "feature" => lint::complete_lint(acc, ctx, &parse_tt_as_comma_sep_paths(tt)?, FEATURES), + "allow" | "warn" | "deny" | "forbid" => { + let existing_lints = parse_tt_as_comma_sep_paths(tt)?; + + let lints: Vec<Lint> = CLIPPY_LINT_GROUPS + .iter() + .map(|g| &g.lint) + .chain(DEFAULT_LINTS) + .chain(CLIPPY_LINTS) + .chain(RUSTDOC_LINTS) + .cloned() + .collect(); + + lint::complete_lint(acc, ctx, &existing_lints, &lints); + } + "cfg" => cfg::complete_cfg(acc, ctx), + _ => (), + } + Some(()) +} + +pub(crate) fn complete_attribute(acc: &mut Completions, ctx: &CompletionContext) { + let (is_absolute_path, qualifier, is_inner, annotated_item_kind) = match ctx.path_context { + Some(PathCompletionCtx { + kind: Some(PathKind::Attr { kind, annotated_item_kind }), + is_absolute_path, + ref qualifier, + .. + }) => (is_absolute_path, qualifier, kind == AttrKind::Inner, annotated_item_kind), + _ => return, + }; + + match qualifier { + Some(PathQualifierCtx { resolution, is_super_chain, .. }) => { + if *is_super_chain { + acc.add_keyword(ctx, "super::"); + } + + let module = match resolution { + Some(hir::PathResolution::Def(hir::ModuleDef::Module(it))) => it, + _ => return, + }; + + for (name, def) in module.scope(ctx.db, Some(ctx.module)) { + if let Some(def) = module_or_attr(ctx.db, def) { + acc.add_resolution(ctx, name, def); + } + } + return; + } + // fresh use tree with leading colon2, only show crate roots + None if is_absolute_path => acc.add_crate_roots(ctx), + // only show modules in a fresh UseTree + None => { + ctx.process_all_names(&mut |name, def| { + if let Some(def) = module_or_attr(ctx.db, def) { + acc.add_resolution(ctx, name, def); + } + }); + acc.add_nameref_keywords_with_colon(ctx); + } + } + + let attributes = annotated_item_kind.and_then(|kind| { + if ast::Expr::can_cast(kind) { + Some(EXPR_ATTRIBUTES) + } else { + KIND_TO_ATTRIBUTES.get(&kind).copied() + } + }); + + let add_completion = |attr_completion: &AttrCompletion| { + let mut item = + CompletionItem::new(SymbolKind::Attribute, ctx.source_range(), attr_completion.label); + + if let Some(lookup) = attr_completion.lookup { + item.lookup_by(lookup); + } + + if let Some((snippet, cap)) = attr_completion.snippet.zip(ctx.config.snippet_cap) { + item.insert_snippet(cap, snippet); + } + + if is_inner || !attr_completion.prefer_inner { + item.add_to(acc); + } + }; + + match attributes { + Some(applicable) => applicable + .iter() + .flat_map(|name| ATTRIBUTES.binary_search_by(|attr| attr.key().cmp(name)).ok()) + .flat_map(|idx| ATTRIBUTES.get(idx)) + .for_each(add_completion), + None if is_inner => ATTRIBUTES.iter().for_each(add_completion), + None => ATTRIBUTES.iter().filter(|compl| !compl.prefer_inner).for_each(add_completion), + } +} + +struct AttrCompletion { + label: &'static str, + lookup: Option<&'static str>, + snippet: Option<&'static str>, + prefer_inner: bool, +} + +impl AttrCompletion { + fn key(&self) -> &'static str { + self.lookup.unwrap_or(self.label) + } + + 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 } +} + +macro_rules! attrs { + // attributes applicable to all items + [@ { item $($tt:tt)* } {$($acc:tt)*}] => { + attrs!(@ { $($tt)* } { $($acc)*, "deprecated", "doc", "dochidden", "docalias", "must_use", "no_mangle" }) + }; + // attributes applicable to all adts + [@ { adt $($tt:tt)* } {$($acc:tt)*}] => { + attrs!(@ { $($tt)* } { $($acc)*, "derive", "repr" }) + }; + // attributes applicable to all linkable things aka functions/statics + [@ { linkable $($tt:tt)* } {$($acc:tt)*}] => { + attrs!(@ { $($tt)* } { $($acc)*, "export_name", "link_name", "link_section" }) + }; + // error fallback for nicer error message + [@ { $ty:ident $($tt:tt)* } {$($acc:tt)*}] => { + compile_error!(concat!("unknown attr subtype ", stringify!($ty))) + }; + // general push down accumulation + [@ { $lit:literal $($tt:tt)*} {$($acc:tt)*}] => { + attrs!(@ { $($tt)* } { $($acc)*, $lit }) + }; + [@ {$($tt:tt)+} {$($tt2:tt)*}] => { + compile_error!(concat!("Unexpected input ", stringify!($($tt)+))) + }; + // final output construction + [@ {} {$($tt:tt)*}] => { &[$($tt)*] as _ }; + // starting matcher + [$($tt:tt),*] => { + attrs!(@ { $($tt)* } { "allow", "cfg", "cfg_attr", "deny", "forbid", "warn" }) + }; +} + +#[rustfmt::skip] +static KIND_TO_ATTRIBUTES: Lazy<FxHashMap<SyntaxKind, &[&str]>> = Lazy::new(|| { + use SyntaxKind::*; + [ + ( + SOURCE_FILE, + attrs!( + item, + "crate_name", "feature", "no_implicit_prelude", "no_main", "no_std", + "recursion_limit", "type_length_limit", "windows_subsystem" + ), + ), + (MODULE, attrs!(item, "macro_use", "no_implicit_prelude", "path")), + (ITEM_LIST, attrs!(item, "no_implicit_prelude")), + (MACRO_RULES, attrs!(item, "macro_export", "macro_use")), + (MACRO_DEF, attrs!(item)), + (EXTERN_CRATE, attrs!(item, "macro_use", "no_link")), + (USE, attrs!(item)), + (TYPE_ALIAS, attrs!(item)), + (STRUCT, attrs!(item, adt, "non_exhaustive")), + (ENUM, attrs!(item, adt, "non_exhaustive")), + (UNION, attrs!(item, adt)), + (CONST, attrs!(item)), + ( + FN, + attrs!( + item, linkable, + "cold", "ignore", "inline", "must_use", "panic_handler", "proc_macro", + "proc_macro_derive", "proc_macro_attribute", "should_panic", "target_feature", + "test", "track_caller" + ), + ), + (STATIC, attrs!(item, linkable, "global_allocator", "used")), + (TRAIT, attrs!(item, "must_use")), + (IMPL, attrs!(item, "automatically_derived")), + (ASSOC_ITEM_LIST, attrs!(item)), + (EXTERN_BLOCK, attrs!(item, "link")), + (EXTERN_ITEM_LIST, attrs!(item, "link")), + (MACRO_CALL, attrs!()), + (SELF_PARAM, attrs!()), + (PARAM, attrs!()), + (RECORD_FIELD, attrs!()), + (VARIANT, attrs!("non_exhaustive")), + (TYPE_PARAM, attrs!()), + (CONST_PARAM, attrs!()), + (LIFETIME_PARAM, attrs!()), + (LET_STMT, attrs!()), + (EXPR_STMT, attrs!()), + (LITERAL, attrs!()), + (RECORD_EXPR_FIELD_LIST, attrs!()), + (RECORD_EXPR_FIELD, attrs!()), + (MATCH_ARM_LIST, attrs!()), + (MATCH_ARM, attrs!()), + (IDENT_PAT, attrs!()), + (RECORD_PAT_FIELD, attrs!()), + ] + .into_iter() + .collect() +}); +const EXPR_ATTRIBUTES: &[&str] = attrs!(); + +/// <https://doc.rust-lang.org/reference/attributes.html#built-in-attributes-index> +// Keep these sorted for the binary search! +const ATTRIBUTES: &[AttrCompletion] = &[ + attr("allow(…)", Some("allow"), Some("allow(${0:lint})")), + attr("automatically_derived", None, None), + attr("cfg(…)", Some("cfg"), Some("cfg(${0:predicate})")), + attr("cfg_attr(…)", Some("cfg_attr"), Some("cfg_attr(${1:predicate}, ${0:attr})")), + attr("cold", None, None), + attr(r#"crate_name = """#, Some("crate_name"), Some(r#"crate_name = "${0:crate_name}""#)) + .prefer_inner(), + attr("deny(…)", Some("deny"), Some("deny(${0:lint})")), + attr(r#"deprecated"#, Some("deprecated"), Some(r#"deprecated"#)), + attr("derive(…)", Some("derive"), Some(r#"derive(${0:Debug})"#)), + attr(r#"doc = "…""#, Some("doc"), Some(r#"doc = "${0:docs}""#)), + attr(r#"doc(alias = "…")"#, Some("docalias"), Some(r#"doc(alias = "${0:docs}")"#)), + attr(r#"doc(hidden)"#, Some("dochidden"), Some(r#"doc(hidden)"#)), + attr( + r#"export_name = "…""#, + Some("export_name"), + Some(r#"export_name = "${0:exported_symbol_name}""#), + ), + attr("feature(…)", Some("feature"), Some("feature(${0:flag})")).prefer_inner(), + attr("forbid(…)", Some("forbid"), Some("forbid(${0:lint})")), + attr("global_allocator", None, None), + attr(r#"ignore = "…""#, Some("ignore"), Some(r#"ignore = "${0:reason}""#)), + attr("inline", Some("inline"), Some("inline")), + attr("link", None, None), + attr(r#"link_name = "…""#, Some("link_name"), Some(r#"link_name = "${0:symbol_name}""#)), + attr( + r#"link_section = "…""#, + Some("link_section"), + Some(r#"link_section = "${0:section_name}""#), + ), + attr("macro_export", None, None), + attr("macro_use", None, None), + attr(r#"must_use"#, Some("must_use"), Some(r#"must_use"#)), + attr("no_implicit_prelude", None, None).prefer_inner(), + attr("no_link", None, None).prefer_inner(), + attr("no_main", None, None).prefer_inner(), + attr("no_mangle", None, None), + attr("no_std", None, None).prefer_inner(), + attr("non_exhaustive", None, None), + attr("panic_handler", None, None), + attr(r#"path = "…""#, Some("path"), Some(r#"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( + r#"recursion_limit = "…""#, + Some("recursion_limit"), + Some(r#"recursion_limit = "${0:128}""#), + ) + .prefer_inner(), + attr("repr(…)", Some("repr"), Some("repr(${0:C})")), + attr("should_panic", Some("should_panic"), Some(r#"should_panic"#)), + attr( + r#"target_feature = "…""#, + Some("target_feature"), + Some(r#"target_feature = "${0:feature}""#), + ), + attr("test", None, None), + attr("track_caller", None, None), + attr("type_length_limit = …", Some("type_length_limit"), Some("type_length_limit = ${0:128}")) + .prefer_inner(), + attr("used", None, None), + attr("warn(…)", Some("warn"), Some("warn(${0:lint})")), + attr( + r#"windows_subsystem = "…""#, + Some("windows_subsystem"), + Some(r#"windows_subsystem = "${0:subsystem}""#), + ) + .prefer_inner(), +]; + +fn parse_comma_sep_expr(input: ast::TokenTree) -> Option<Vec<ast::Expr>> { + let r_paren = input.r_paren_token()?; + let tokens = input + .syntax() + .children_with_tokens() + .skip(1) + .take_while(|it| it.as_token() != Some(&r_paren)); + let input_expressions = tokens.group_by(|tok| tok.kind() == T![,]); + Some( + input_expressions + .into_iter() + .filter_map(|(is_sep, group)| (!is_sep).then(|| group)) + .filter_map(|mut tokens| syntax::hacks::parse_expr_from_str(&tokens.join(""))) + .collect::<Vec<ast::Expr>>(), + ) +} + +#[test] +fn attributes_are_sorted() { + let mut attrs = ATTRIBUTES.iter().map(|attr| attr.key()); + let mut prev = attrs.next().unwrap(); + + attrs.for_each(|next| { + assert!( + prev < next, + r#"ATTRIBUTES array is not sorted, "{}" should come after "{}""#, + prev, + next + ); + prev = next; + }); +} |