1 //! Logic for rendering the different hover messages
3 use hir::{AsAssocItem, HasAttrs, HasSource, HirDisplay, Semantics, TypeInfo};
5 base_db::SourceDatabase,
8 generated_lints::{CLIPPY_LINTS, DEFAULT_LINTS, FEATURES},
13 use itertools::Itertools;
17 display::{fn_as_proc_macro_label, macro_label},
18 match_ast, AstNode, Direction,
19 SyntaxKind::{CONDITION, LET_STMT},
24 doc_links::{remove_links, rewrite_links},
25 hover::walk_and_push_ty,
26 markdown_remove::remove_markdown,
27 HoverAction, HoverConfig, HoverResult, Markup,
30 pub(super) fn type_info(
31 sema: &Semantics<RootDatabase>,
33 expr_or_pat: &Either<ast::Expr, ast::Pat>,
34 ) -> Option<HoverResult> {
35 let TypeInfo { original, adjusted } = match expr_or_pat {
36 Either::Left(expr) => sema.type_of_expr(expr)?,
37 Either::Right(pat) => sema.type_of_pat(pat)?,
40 let mut res = HoverResult::default();
41 let mut targets: Vec<hir::ModuleDef> = Vec::new();
42 let mut push_new_def = |item: hir::ModuleDef| {
43 if !targets.contains(&item) {
47 walk_and_push_ty(sema.db, &original, &mut push_new_def);
49 res.markup = if let Some(adjusted_ty) = adjusted {
50 walk_and_push_ty(sema.db, &adjusted_ty, &mut push_new_def);
51 let original = original.display(sema.db).to_string();
52 let adjusted = adjusted_ty.display(sema.db).to_string();
53 let static_text_diff_len = "Coerced to: ".len() - "Type: ".len();
55 "{bt_start}Type: {:>apad$}\nCoerced to: {:>opad$}\n{bt_end}",
58 apad = static_text_diff_len + adjusted.len().max(original.len()),
59 opad = original.len(),
60 bt_start = if config.markdown() { "```text\n" } else { "" },
61 bt_end = if config.markdown() { "```\n" } else { "" }
65 if config.markdown() {
66 Markup::fenced_block(&original.display(sema.db))
68 original.display(sema.db).to_string().into()
71 res.actions.push(HoverAction::goto_type_from_targets(sema.db, targets));
75 pub(super) fn try_expr(
76 sema: &Semantics<RootDatabase>,
78 try_expr: &ast::TryExpr,
79 ) -> Option<HoverResult> {
80 let inner_ty = sema.type_of_expr(&try_expr.expr()?)?.original;
81 let mut ancestors = try_expr.syntax().ancestors();
82 let mut body_ty = loop {
83 let next = ancestors.next()?;
86 ast::Fn(fn_) => sema.to_def(&fn_)?.ret_type(sema.db),
87 ast::Item(__) => return None,
88 ast::ClosureExpr(closure) => sema.type_of_expr(&closure.body()?)?.original,
89 ast::BlockExpr(block_expr) => if matches!(block_expr.modifier(), Some(ast::BlockModifier::Async(_) | ast::BlockModifier::Try(_)| ast::BlockModifier::Const(_))) {
90 sema.type_of_expr(&block_expr.into())?.original
99 if inner_ty == body_ty {
103 let mut inner_ty = inner_ty;
104 let mut s = "Try Target".to_owned();
106 let adts = inner_ty.as_adt().zip(body_ty.as_adt());
107 if let Some((hir::Adt::Enum(inner), hir::Adt::Enum(body))) = adts {
108 let famous_defs = FamousDefs(sema, sema.scope(&try_expr.syntax()).krate());
109 // special case for two options, there is no value in showing them
110 if let Some(option_enum) = famous_defs.core_option_Option() {
111 if inner == option_enum && body == option_enum {
112 cov_mark::hit!(hover_try_expr_opt_opt);
117 // special case two results to show the error variants only
118 if let Some(result_enum) = famous_defs.core_result_Result() {
119 if inner == result_enum && body == result_enum {
120 let error_type_args =
121 inner_ty.type_arguments().nth(1).zip(body_ty.type_arguments().nth(1));
122 if let Some((inner, body)) = error_type_args {
125 s = "Try Error".to_owned();
131 let mut res = HoverResult::default();
133 let mut targets: Vec<hir::ModuleDef> = Vec::new();
134 let mut push_new_def = |item: hir::ModuleDef| {
135 if !targets.contains(&item) {
139 walk_and_push_ty(sema.db, &inner_ty, &mut push_new_def);
140 walk_and_push_ty(sema.db, &body_ty, &mut push_new_def);
141 res.actions.push(HoverAction::goto_type_from_targets(sema.db, targets));
143 let inner_ty = inner_ty.display(sema.db).to_string();
144 let body_ty = body_ty.display(sema.db).to_string();
145 let ty_len_max = inner_ty.len().max(body_ty.len());
147 let l = "Propagated as: ".len() - " Type: ".len();
148 let static_text_len_diff = l as isize - s.len() as isize;
149 let tpad = static_text_len_diff.max(0) as usize;
150 let ppad = static_text_len_diff.min(0).abs() as usize;
152 res.markup = format!(
153 "{bt_start}{} Type: {:>pad0$}\nPropagated as: {:>pad1$}\n{bt_end}",
157 pad0 = ty_len_max + tpad,
158 pad1 = ty_len_max + ppad,
159 bt_start = if config.markdown() { "```text\n" } else { "" },
160 bt_end = if config.markdown() { "```\n" } else { "" }
166 pub(super) fn deref_expr(
167 sema: &Semantics<RootDatabase>,
168 config: &HoverConfig,
169 deref_expr: &ast::PrefixExpr,
170 ) -> Option<HoverResult> {
171 let inner_ty = sema.type_of_expr(&deref_expr.expr()?)?.original;
172 let TypeInfo { original, adjusted } =
173 sema.type_of_expr(&ast::Expr::from(deref_expr.clone()))?;
175 let mut res = HoverResult::default();
176 let mut targets: Vec<hir::ModuleDef> = Vec::new();
177 let mut push_new_def = |item: hir::ModuleDef| {
178 if !targets.contains(&item) {
182 walk_and_push_ty(sema.db, &inner_ty, &mut push_new_def);
183 walk_and_push_ty(sema.db, &original, &mut push_new_def);
185 res.markup = if let Some(adjusted_ty) = adjusted {
186 walk_and_push_ty(sema.db, &adjusted_ty, &mut push_new_def);
187 let original = original.display(sema.db).to_string();
188 let adjusted = adjusted_ty.display(sema.db).to_string();
189 let inner = inner_ty.display(sema.db).to_string();
190 let type_len = "To type: ".len();
191 let coerced_len = "Coerced to: ".len();
192 let deref_len = "Dereferenced from: ".len();
193 let max_len = (original.len() + type_len)
194 .max(adjusted.len() + coerced_len)
195 .max(inner.len() + deref_len);
197 "{bt_start}Dereferenced from: {:>ipad$}\nTo type: {:>apad$}\nCoerced to: {:>opad$}\n{bt_end}",
201 ipad = max_len - deref_len,
202 apad = max_len - type_len,
203 opad = max_len - coerced_len,
204 bt_start = if config.markdown() { "```text\n" } else { "" },
205 bt_end = if config.markdown() { "```\n" } else { "" }
209 let original = original.display(sema.db).to_string();
210 let inner = inner_ty.display(sema.db).to_string();
211 let type_len = "To type: ".len();
212 let deref_len = "Dereferenced from: ".len();
213 let max_len = (original.len() + type_len).max(inner.len() + deref_len);
215 "{bt_start}Dereferenced from: {:>ipad$}\nTo type: {:>apad$}\n{bt_end}",
218 ipad = max_len - deref_len,
219 apad = max_len - type_len,
220 bt_start = if config.markdown() { "```text\n" } else { "" },
221 bt_end = if config.markdown() { "```\n" } else { "" }
225 res.actions.push(HoverAction::goto_type_from_targets(sema.db, targets));
230 pub(super) fn keyword(
231 sema: &Semantics<RootDatabase>,
232 config: &HoverConfig,
234 ) -> Option<HoverResult> {
235 if !token.kind().is_keyword() || !config.documentation.is_some() {
238 let famous_defs = FamousDefs(sema, sema.scope(&token.parent()?).krate());
239 // std exposes {}_keyword modules with docstrings on the root to document keywords
240 let keyword_mod = format!("{}_keyword", token.text());
241 let doc_owner = find_std_module(&famous_defs, &keyword_mod)?;
242 let docs = doc_owner.attrs(sema.db).docs()?;
243 let markup = process_markup(
245 Definition::ModuleDef(doc_owner.into()),
246 &markup(Some(docs.into()), token.text().into(), None)?,
249 Some(HoverResult { markup, actions: Default::default() })
252 pub(super) fn try_for_lint(attr: &ast::Attr, token: &SyntaxToken) -> Option<HoverResult> {
253 let (path, tt) = attr.as_simple_call()?;
254 if !tt.syntax().text_range().contains(token.text_range().start()) {
257 let (is_clippy, lints) = match &*path {
258 "feature" => (false, FEATURES),
259 "allow" | "deny" | "forbid" | "warn" => {
260 let is_clippy = algo::non_trivia_sibling(token.clone().into(), Direction::Prev)
261 .filter(|t| t.kind() == T![:])
262 .and_then(|t| algo::non_trivia_sibling(t, Direction::Prev))
263 .filter(|t| t.kind() == T![:])
264 .and_then(|t| algo::non_trivia_sibling(t, Direction::Prev))
266 t.kind() == T![ident] && t.into_token().map_or(false, |t| t.text() == "clippy")
271 (false, DEFAULT_LINTS)
278 let needle = if is_clippy {
279 tmp = format!("clippy::{}", token.text());
286 lints.binary_search_by_key(&needle, |lint| lint.label).ok().map(|idx| &lints[idx])?;
288 markup: Markup::from(format!("```\n{}\n```\n___\n\n{}", lint.label, lint.description)),
293 pub(super) fn process_markup(
297 config: &HoverConfig,
299 let markup = markup.as_str();
300 let markup = if !config.markdown() {
301 remove_markdown(markup)
302 } else if config.links_in_hover {
303 rewrite_links(db, markup, def)
310 fn definition_owner_name(db: &RootDatabase, def: &Definition) -> Option<String> {
312 Definition::Field(f) => Some(f.parent_def(db).name(db)),
313 Definition::Local(l) => l.parent(db).name(db),
314 Definition::ModuleDef(md) => match md {
315 hir::ModuleDef::Function(f) => match f.as_assoc_item(db)?.container(db) {
316 hir::AssocItemContainer::Trait(t) => Some(t.name(db)),
317 hir::AssocItemContainer::Impl(i) => i.self_ty(db).as_adt().map(|adt| adt.name(db)),
319 hir::ModuleDef::Variant(e) => Some(e.parent_enum(db).name(db)),
324 .map(|name| name.to_string())
327 pub(super) fn path(db: &RootDatabase, module: hir::Module, item_name: Option<String>) -> String {
329 db.crate_graph()[module.krate().into()].display_name.as_ref().map(|it| it.to_string());
330 let module_path = module
334 .flat_map(|it| it.name(db).map(|name| name.to_string()));
335 crate_name.into_iter().chain(module_path).chain(item_name).join("::")
338 pub(super) fn definition(
341 famous_defs: Option<&FamousDefs>,
342 config: &HoverConfig,
343 ) -> Option<Markup> {
344 let mod_path = definition_mod_path(db, &def);
345 let (label, docs) = match def {
346 Definition::Macro(it) => (
347 match &it.source(db)?.value {
348 Either::Left(mac) => macro_label(mac),
349 Either::Right(mac_fn) => fn_as_proc_macro_label(mac_fn),
353 Definition::Field(def) => label_and_docs(db, def),
354 Definition::ModuleDef(it) => match it {
355 hir::ModuleDef::Module(it) => label_and_docs(db, it),
356 hir::ModuleDef::Function(it) => label_and_docs(db, it),
357 hir::ModuleDef::Adt(it) => label_and_docs(db, it),
358 hir::ModuleDef::Variant(it) => label_and_docs(db, it),
359 hir::ModuleDef::Const(it) => label_and_docs(db, it),
360 hir::ModuleDef::Static(it) => label_and_docs(db, it),
361 hir::ModuleDef::Trait(it) => label_and_docs(db, it),
362 hir::ModuleDef::TypeAlias(it) => label_and_docs(db, it),
363 hir::ModuleDef::BuiltinType(it) => {
365 .and_then(|fd| builtin(fd, it))
366 .or_else(|| Some(Markup::fenced_block(&it.name())))
369 Definition::Local(it) => return local(db, it),
370 Definition::SelfType(impl_def) => {
371 impl_def.self_ty(db).as_adt().map(|adt| label_and_docs(db, adt))?
373 Definition::GenericParam(it) => label_and_docs(db, it),
374 Definition::Label(it) => return Some(Markup::fenced_block(&it.name(db))),
377 markup(docs.filter(|_| config.documentation.is_some()).map(Into::into), label, mod_path)
380 fn label_and_docs<D>(db: &RootDatabase, def: D) -> (String, Option<hir::Documentation>)
382 D: HasAttrs + HirDisplay,
384 let label = def.display(db).to_string();
385 let docs = def.attrs(db).docs();
389 fn definition_mod_path(db: &RootDatabase, def: &Definition) -> Option<String> {
390 if let Definition::GenericParam(_) = def {
393 def.module(db).map(|module| path(db, module, definition_owner_name(db, def)))
396 fn markup(docs: Option<String>, desc: String, mod_path: Option<String>) -> Option<Markup> {
397 let mut buf = String::new();
399 if let Some(mod_path) = mod_path {
400 if !mod_path.is_empty() {
401 format_to!(buf, "```rust\n{}\n```\n\n", mod_path);
404 format_to!(buf, "```rust\n{}\n```", desc);
406 if let Some(doc) = docs {
407 format_to!(buf, "\n___\n\n{}", doc);
412 fn builtin(famous_defs: &FamousDefs, builtin: hir::BuiltinType) -> Option<Markup> {
413 // std exposes prim_{} modules with docstrings on the root to document the builtins
414 let primitive_mod = format!("prim_{}", builtin.name());
415 let doc_owner = find_std_module(famous_defs, &primitive_mod)?;
416 let docs = doc_owner.attrs(famous_defs.0.db).docs()?;
417 markup(Some(docs.into()), builtin.name().to_string(), None)
420 fn find_std_module(famous_defs: &FamousDefs, name: &str) -> Option<hir::Module> {
421 let db = famous_defs.0.db;
422 let std_crate = famous_defs.std()?;
423 let std_root_module = std_crate.root_module(db);
426 .find(|module| module.name(db).map_or(false, |module| module.to_string() == name))
429 fn local(db: &RootDatabase, it: hir::Local) -> Option<Markup> {
431 let ty = ty.display(db);
432 let is_mut = if it.is_mut(db) { "mut " } else { "" };
433 let desc = match it.source(db).value {
434 Either::Left(ident) => {
435 let name = it.name(db).unwrap();
436 let let_kw = if ident
439 .map_or(false, |p| p.kind() == LET_STMT || p.kind() == CONDITION)
445 format!("{}{}{}: {}", let_kw, is_mut, name, ty)
447 Either::Right(_) => format!("{}self: {}", is_mut, ty),
449 markup(None, desc, None)