rust-analyzer/crates/ide/src/hover/render.rs
2021-11-18 06:00:51 +00:00

466 lines
16 KiB
Rust

//! Logic for rendering the different hover messages
use std::fmt::Display;
use either::Either;
use hir::{AsAssocItem, HasAttrs, HasSource, HirDisplay, Semantics, TypeInfo};
use ide_db::{
base_db::SourceDatabase,
defs::Definition,
helpers::{
generated_lints::{CLIPPY_LINTS, DEFAULT_LINTS, FEATURES},
FamousDefs,
},
RootDatabase,
};
use itertools::Itertools;
use stdx::format_to;
use syntax::{
algo, ast,
display::{fn_as_proc_macro_label, macro_label},
match_ast, AstNode, Direction,
SyntaxKind::{CONDITION, LET_STMT},
SyntaxToken, T,
};
use crate::{
doc_links::{remove_links, rewrite_links},
hover::walk_and_push_ty,
markdown_remove::remove_markdown,
HoverAction, HoverConfig, HoverResult, Markup,
};
pub(super) fn type_info(
sema: &Semantics<RootDatabase>,
config: &HoverConfig,
expr_or_pat: &Either<ast::Expr, ast::Pat>,
) -> Option<HoverResult> {
let TypeInfo { original, adjusted } = match expr_or_pat {
Either::Left(expr) => sema.type_of_expr(expr)?,
Either::Right(pat) => sema.type_of_pat(pat)?,
};
let mut res = HoverResult::default();
let mut targets: Vec<hir::ModuleDef> = Vec::new();
let mut push_new_def = |item: hir::ModuleDef| {
if !targets.contains(&item) {
targets.push(item);
}
};
walk_and_push_ty(sema.db, &original, &mut push_new_def);
res.markup = if let Some(adjusted_ty) = adjusted {
walk_and_push_ty(sema.db, &adjusted_ty, &mut push_new_def);
let original = original.display(sema.db).to_string();
let adjusted = adjusted_ty.display(sema.db).to_string();
let static_text_diff_len = "Coerced to: ".len() - "Type: ".len();
format!(
"{bt_start}Type: {:>apad$}\nCoerced to: {:>opad$}\n{bt_end}",
original,
adjusted,
apad = static_text_diff_len + adjusted.len().max(original.len()),
opad = original.len(),
bt_start = if config.markdown() { "```text\n" } else { "" },
bt_end = if config.markdown() { "```\n" } else { "" }
)
.into()
} else {
if config.markdown() {
Markup::fenced_block(&original.display(sema.db))
} else {
original.display(sema.db).to_string().into()
}
};
res.actions.push(HoverAction::goto_type_from_targets(sema.db, targets));
Some(res)
}
pub(super) fn try_expr(
sema: &Semantics<RootDatabase>,
config: &HoverConfig,
try_expr: &ast::TryExpr,
) -> Option<HoverResult> {
let inner_ty = sema.type_of_expr(&try_expr.expr()?)?.original;
let mut ancestors = try_expr.syntax().ancestors();
let mut body_ty = loop {
let next = ancestors.next()?;
break match_ast! {
match next {
ast::Fn(fn_) => sema.to_def(&fn_)?.ret_type(sema.db),
ast::Item(__) => return None,
ast::ClosureExpr(closure) => sema.type_of_expr(&closure.body()?)?.original,
ast::BlockExpr(block_expr) => if matches!(block_expr.modifier(), Some(ast::BlockModifier::Async(_) | ast::BlockModifier::Try(_)| ast::BlockModifier::Const(_))) {
sema.type_of_expr(&block_expr.into())?.original
} else {
continue;
},
_ => continue,
}
};
};
if inner_ty == body_ty {
return None;
}
let mut inner_ty = inner_ty;
let mut s = "Try Target".to_owned();
let adts = inner_ty.as_adt().zip(body_ty.as_adt());
if let Some((hir::Adt::Enum(inner), hir::Adt::Enum(body))) = adts {
let famous_defs = FamousDefs(sema, sema.scope(&try_expr.syntax()).krate());
// special case for two options, there is no value in showing them
if let Some(option_enum) = famous_defs.core_option_Option() {
if inner == option_enum && body == option_enum {
cov_mark::hit!(hover_try_expr_opt_opt);
return None;
}
}
// special case two results to show the error variants only
if let Some(result_enum) = famous_defs.core_result_Result() {
if inner == result_enum && body == result_enum {
let error_type_args =
inner_ty.type_arguments().nth(1).zip(body_ty.type_arguments().nth(1));
if let Some((inner, body)) = error_type_args {
inner_ty = inner;
body_ty = body;
s = "Try Error".to_owned();
}
}
}
}
let mut res = HoverResult::default();
let mut targets: Vec<hir::ModuleDef> = Vec::new();
let mut push_new_def = |item: hir::ModuleDef| {
if !targets.contains(&item) {
targets.push(item);
}
};
walk_and_push_ty(sema.db, &inner_ty, &mut push_new_def);
walk_and_push_ty(sema.db, &body_ty, &mut push_new_def);
res.actions.push(HoverAction::goto_type_from_targets(sema.db, targets));
let inner_ty = inner_ty.display(sema.db).to_string();
let body_ty = body_ty.display(sema.db).to_string();
let ty_len_max = inner_ty.len().max(body_ty.len());
let l = "Propagated as: ".len() - " Type: ".len();
let static_text_len_diff = l as isize - s.len() as isize;
let tpad = static_text_len_diff.max(0) as usize;
let ppad = static_text_len_diff.min(0).abs() as usize;
res.markup = format!(
"{bt_start}{} Type: {:>pad0$}\nPropagated as: {:>pad1$}\n{bt_end}",
s,
inner_ty,
body_ty,
pad0 = ty_len_max + tpad,
pad1 = ty_len_max + ppad,
bt_start = if config.markdown() { "```text\n" } else { "" },
bt_end = if config.markdown() { "```\n" } else { "" }
)
.into();
Some(res)
}
pub(super) fn deref_expr(
sema: &Semantics<RootDatabase>,
config: &HoverConfig,
deref_expr: &ast::PrefixExpr,
) -> Option<HoverResult> {
let inner_ty = sema.type_of_expr(&deref_expr.expr()?)?.original;
let TypeInfo { original, adjusted } =
sema.type_of_expr(&ast::Expr::from(deref_expr.clone()))?;
let mut res = HoverResult::default();
let mut targets: Vec<hir::ModuleDef> = Vec::new();
let mut push_new_def = |item: hir::ModuleDef| {
if !targets.contains(&item) {
targets.push(item);
}
};
walk_and_push_ty(sema.db, &inner_ty, &mut push_new_def);
walk_and_push_ty(sema.db, &original, &mut push_new_def);
res.markup = if let Some(adjusted_ty) = adjusted {
walk_and_push_ty(sema.db, &adjusted_ty, &mut push_new_def);
let original = original.display(sema.db).to_string();
let adjusted = adjusted_ty.display(sema.db).to_string();
let inner = inner_ty.display(sema.db).to_string();
let type_len = "To type: ".len();
let coerced_len = "Coerced to: ".len();
let deref_len = "Dereferenced from: ".len();
let max_len = (original.len() + type_len)
.max(adjusted.len() + coerced_len)
.max(inner.len() + deref_len);
format!(
"{bt_start}Dereferenced from: {:>ipad$}\nTo type: {:>apad$}\nCoerced to: {:>opad$}\n{bt_end}",
inner,
original,
adjusted,
ipad = max_len - deref_len,
apad = max_len - type_len,
opad = max_len - coerced_len,
bt_start = if config.markdown() { "```text\n" } else { "" },
bt_end = if config.markdown() { "```\n" } else { "" }
)
.into()
} else {
let original = original.display(sema.db).to_string();
let inner = inner_ty.display(sema.db).to_string();
let type_len = "To type: ".len();
let deref_len = "Dereferenced from: ".len();
let max_len = (original.len() + type_len).max(inner.len() + deref_len);
format!(
"{bt_start}Dereferenced from: {:>ipad$}\nTo type: {:>apad$}\n{bt_end}",
inner,
original,
ipad = max_len - deref_len,
apad = max_len - type_len,
bt_start = if config.markdown() { "```text\n" } else { "" },
bt_end = if config.markdown() { "```\n" } else { "" }
)
.into()
};
res.actions.push(HoverAction::goto_type_from_targets(sema.db, targets));
Some(res)
}
pub(super) fn keyword(
sema: &Semantics<RootDatabase>,
config: &HoverConfig,
token: &SyntaxToken,
) -> Option<HoverResult> {
if !token.kind().is_keyword() || !config.documentation.is_some() {
return None;
}
let famous_defs = FamousDefs(sema, sema.scope(&token.parent()?).krate());
// std exposes {}_keyword modules with docstrings on the root to document keywords
let keyword_mod = format!("{}_keyword", token.text());
let doc_owner = find_std_module(&famous_defs, &keyword_mod)?;
let docs = doc_owner.attrs(sema.db).docs()?;
let markup = process_markup(
sema.db,
Definition::Module(doc_owner),
&markup(Some(docs.into()), token.text().into(), None)?,
config,
);
Some(HoverResult { markup, actions: Default::default() })
}
pub(super) fn try_for_lint(attr: &ast::Attr, token: &SyntaxToken) -> Option<HoverResult> {
let (path, tt) = attr.as_simple_call()?;
if !tt.syntax().text_range().contains(token.text_range().start()) {
return None;
}
let (is_clippy, lints) = match &*path {
"feature" => (false, FEATURES),
"allow" | "deny" | "forbid" | "warn" => {
let is_clippy = algo::non_trivia_sibling(token.clone().into(), Direction::Prev)
.filter(|t| t.kind() == T![:])
.and_then(|t| algo::non_trivia_sibling(t, Direction::Prev))
.filter(|t| t.kind() == T![:])
.and_then(|t| algo::non_trivia_sibling(t, Direction::Prev))
.map_or(false, |t| {
t.kind() == T![ident] && t.into_token().map_or(false, |t| t.text() == "clippy")
});
if is_clippy {
(true, CLIPPY_LINTS)
} else {
(false, DEFAULT_LINTS)
}
}
_ => return None,
};
let tmp;
let needle = if is_clippy {
tmp = format!("clippy::{}", token.text());
&tmp
} else {
&*token.text()
};
let lint =
lints.binary_search_by_key(&needle, |lint| lint.label).ok().map(|idx| &lints[idx])?;
Some(HoverResult {
markup: Markup::from(format!("```\n{}\n```\n___\n\n{}", lint.label, lint.description)),
..Default::default()
})
}
pub(super) fn process_markup(
db: &RootDatabase,
def: Definition,
markup: &Markup,
config: &HoverConfig,
) -> Markup {
let markup = markup.as_str();
let markup = if !config.markdown() {
remove_markdown(markup)
} else if config.links_in_hover {
rewrite_links(db, markup, def)
} else {
remove_links(markup)
};
Markup::from(markup)
}
fn definition_owner_name(db: &RootDatabase, def: &Definition) -> Option<String> {
match def {
Definition::Field(f) => Some(f.parent_def(db).name(db)),
Definition::Local(l) => l.parent(db).name(db),
Definition::Function(f) => match f.as_assoc_item(db)?.container(db) {
hir::AssocItemContainer::Trait(t) => Some(t.name(db)),
hir::AssocItemContainer::Impl(i) => i.self_ty(db).as_adt().map(|adt| adt.name(db)),
},
Definition::Variant(e) => Some(e.parent_enum(db).name(db)),
_ => None,
}
.map(|name| name.to_string())
}
pub(super) fn path(db: &RootDatabase, module: hir::Module, item_name: Option<String>) -> String {
let crate_name =
db.crate_graph()[module.krate().into()].display_name.as_ref().map(|it| it.to_string());
let module_path = module
.path_to_root(db)
.into_iter()
.rev()
.flat_map(|it| it.name(db).map(|name| name.to_string()));
crate_name.into_iter().chain(module_path).chain(item_name).join("::")
}
pub(super) fn definition(
db: &RootDatabase,
def: Definition,
famous_defs: Option<&FamousDefs>,
config: &HoverConfig,
) -> Option<Markup> {
let mod_path = definition_mod_path(db, &def);
let (label, docs) = match def {
Definition::Macro(it) => (
match &it.source(db)?.value {
Either::Left(mac) => macro_label(mac),
Either::Right(mac_fn) => fn_as_proc_macro_label(mac_fn),
},
it.attrs(db).docs(),
),
Definition::Field(def) => label_and_docs(db, def),
Definition::Module(it) => label_and_docs(db, it),
Definition::Function(it) => label_and_docs(db, it),
Definition::Adt(it) => label_and_docs(db, it),
Definition::Variant(it) => label_and_docs(db, it),
Definition::Const(it) => label_value_and_docs(db, it, |it| it.value(db)),
Definition::Static(it) => label_value_and_docs(db, it, |it| it.value(db)),
Definition::Trait(it) => label_and_docs(db, it),
Definition::TypeAlias(it) => label_and_docs(db, it),
Definition::BuiltinType(it) => {
return famous_defs
.and_then(|fd| builtin(fd, it))
.or_else(|| Some(Markup::fenced_block(&it.name())))
}
Definition::Local(it) => return local(db, it),
Definition::SelfType(impl_def) => {
impl_def.self_ty(db).as_adt().map(|adt| label_and_docs(db, adt))?
}
Definition::GenericParam(it) => label_and_docs(db, it),
Definition::Label(it) => return Some(Markup::fenced_block(&it.name(db))),
};
markup(docs.filter(|_| config.documentation.is_some()).map(Into::into), label, mod_path)
}
fn label_and_docs<D>(db: &RootDatabase, def: D) -> (String, Option<hir::Documentation>)
where
D: HasAttrs + HirDisplay,
{
let label = def.display(db).to_string();
let docs = def.attrs(db).docs();
(label, docs)
}
fn label_value_and_docs<D, E, V>(
db: &RootDatabase,
def: D,
value_extractor: E,
) -> (String, Option<hir::Documentation>)
where
D: HasAttrs + HirDisplay,
E: Fn(&D) -> Option<V>,
V: Display,
{
let label = if let Some(value) = (value_extractor)(&def) {
format!("{} = {}", def.display(db), value)
} else {
def.display(db).to_string()
};
let docs = def.attrs(db).docs();
(label, docs)
}
fn definition_mod_path(db: &RootDatabase, def: &Definition) -> Option<String> {
if let Definition::GenericParam(_) = def {
return None;
}
def.module(db).map(|module| path(db, module, definition_owner_name(db, def)))
}
fn markup(docs: Option<String>, desc: String, mod_path: Option<String>) -> Option<Markup> {
let mut buf = String::new();
if let Some(mod_path) = mod_path {
if !mod_path.is_empty() {
format_to!(buf, "```rust\n{}\n```\n\n", mod_path);
}
}
format_to!(buf, "```rust\n{}\n```", desc);
if let Some(doc) = docs {
format_to!(buf, "\n___\n\n{}", doc);
}
Some(buf.into())
}
fn builtin(famous_defs: &FamousDefs, builtin: hir::BuiltinType) -> Option<Markup> {
// std exposes prim_{} modules with docstrings on the root to document the builtins
let primitive_mod = format!("prim_{}", builtin.name());
let doc_owner = find_std_module(famous_defs, &primitive_mod)?;
let docs = doc_owner.attrs(famous_defs.0.db).docs()?;
markup(Some(docs.into()), builtin.name().to_string(), None)
}
fn find_std_module(famous_defs: &FamousDefs, name: &str) -> Option<hir::Module> {
let db = famous_defs.0.db;
let std_crate = famous_defs.std()?;
let std_root_module = std_crate.root_module(db);
std_root_module
.children(db)
.find(|module| module.name(db).map_or(false, |module| module.to_string() == name))
}
fn local(db: &RootDatabase, it: hir::Local) -> Option<Markup> {
let ty = it.ty(db);
let ty = ty.display(db);
let is_mut = if it.is_mut(db) { "mut " } else { "" };
let desc = match it.source(db).value {
Either::Left(ident) => {
let name = it.name(db).unwrap();
let let_kw = if ident
.syntax()
.parent()
.map_or(false, |p| p.kind() == LET_STMT || p.kind() == CONDITION)
{
"let "
} else {
""
};
format!("{}{}{}: {}", let_kw, is_mut, name, ty)
}
Either::Right(_) => format!("{}self: {}", is_mut, ty),
};
markup(None, desc, None)
}