4 use ide_db::{helpers::pick_best_token, RootDatabase};
5 use syntax::{ast, ted, AstNode, NodeOrToken, SyntaxKind, SyntaxKind::*, SyntaxNode, WalkEvent, T};
7 use crate::FilePosition;
9 pub struct ExpandedMacro {
11 pub expansion: String,
14 // Feature: Expand Macro Recursively
16 // Shows the full macro expansion of the macro at current cursor.
19 // | Editor | Action Name
21 // | VS Code | **Rust Analyzer: Expand macro recursively**
24 // image::https://user-images.githubusercontent.com/48062697/113020648-b3973180-917a-11eb-84a9-ecb921293dc5.gif[]
25 pub(crate) fn expand_macro(db: &RootDatabase, position: FilePosition) -> Option<ExpandedMacro> {
26 let sema = Semantics::new(db);
27 let file = sema.parse(position.file_id);
29 let tok = pick_best_token(file.syntax().token_at_offset(position.offset), |kind| match kind {
30 SyntaxKind::IDENT => 1,
33 let mut expanded = None;
35 for node in tok.ancestors() {
36 if let Some(item) = ast::Item::cast(node.clone()) {
37 if let Some(def) = sema.resolve_attr_macro_call(&item) {
38 name = def.name(db).map(|name| name.to_string());
39 expanded = expand_attr_macro_recur(&sema, &item);
44 if let Some(mac) = ast::MacroCall::cast(node) {
45 name = Some(mac.path()?.segment()?.name_ref()?.to_string());
46 expanded = expand_macro_recur(&sema, &mac);
52 // macro expansion may lose all white space information
53 // But we hope someday we can use ra_fmt for that
54 let expansion = insert_whitespaces(expanded?);
55 Some(ExpandedMacro { name: name.unwrap_or_else(|| "???".to_owned()), expansion })
58 fn expand_macro_recur(
59 sema: &Semantics<RootDatabase>,
60 macro_call: &ast::MacroCall,
61 ) -> Option<SyntaxNode> {
62 let expanded = sema.expand(macro_call)?.clone_for_update();
63 expand(sema, expanded, ast::MacroCall::cast, expand_macro_recur)
66 fn expand_attr_macro_recur(sema: &Semantics<RootDatabase>, item: &ast::Item) -> Option<SyntaxNode> {
67 let expanded = sema.expand_attr_macro(item)?.clone_for_update();
68 expand(sema, expanded, ast::Item::cast, expand_attr_macro_recur)
71 fn expand<T: AstNode>(
72 sema: &Semantics<RootDatabase>,
74 f: impl FnMut(SyntaxNode) -> Option<T>,
75 exp: impl Fn(&Semantics<RootDatabase>, &T) -> Option<SyntaxNode>,
76 ) -> Option<SyntaxNode> {
77 let children = expanded.descendants().filter_map(f);
78 let mut replacements = Vec::new();
80 for child in children {
81 if let Some(new_node) = exp(sema, &child) {
82 // check if the whole original syntax is replaced
83 if expanded == *child.syntax() {
84 return Some(new_node);
86 replacements.push((child, new_node));
90 replacements.into_iter().rev().for_each(|(old, new)| ted::replace(old.syntax(), new));
94 // FIXME: It would also be cool to share logic here and in the mbe tests,
95 // which are pretty unreadable at the moment.
96 fn insert_whitespaces(syn: SyntaxNode) -> String {
97 let mut res = String::new();
98 let mut token_iter = syn
99 .preorder_with_tokens()
100 .filter_map(|event| {
101 if let WalkEvent::Enter(NodeOrToken::Token(token)) = event {
110 let mut last: Option<SyntaxKind> = None;
112 while let Some(token) = token_iter.next() {
113 let mut is_next = |f: fn(SyntaxKind) -> bool, default| -> bool {
114 token_iter.peek().map(|it| f(it.kind())).unwrap_or(default)
117 |f: fn(SyntaxKind) -> bool, default| -> bool { last.map(f).unwrap_or(default) };
120 k if is_text(k) && is_next(|it| !it.is_punct(), true) => {
121 res.push_str(token.text());
124 L_CURLY if is_next(|it| it != R_CURLY, true) => {
126 if is_last(is_text, false) {
130 res.extend(iter::repeat(" ").take(2 * indent));
132 R_CURLY if is_last(|it| it != L_CURLY, true) => {
133 indent = indent.saturating_sub(1);
135 res.extend(iter::repeat(" ").take(2 * indent));
140 res.extend(iter::repeat(" ").take(2 * indent));
142 LIFETIME_IDENT if is_next(|it| it == IDENT, true) => {
143 res.push_str(token.text());
148 res.extend(iter::repeat(" ").take(2 * indent));
150 T![->] => res.push_str(" -> "),
151 T![=] => res.push_str(" = "),
152 T![=>] => res.push_str(" => "),
153 _ => res.push_str(token.text()),
156 last = Some(token.kind());
161 fn is_text(k: SyntaxKind) -> bool {
162 k.is_keyword() || k.is_literal() || k == IDENT
168 use expect_test::{expect, Expect};
172 fn check(ra_fixture: &str, expect: Expect) {
173 let (analysis, pos) = fixture::position(ra_fixture);
174 let expansion = analysis.expand_macro(pos).unwrap().unwrap();
175 let actual = format!("{}\n{}", expansion.name, expansion.expansion);
176 expect.assert_eq(&actual);
180 fn macro_expand_recursive_expansion() {
202 fn macro_expand_multiple_lines() {
207 fn some_thing() -> u32 {
217 fn some_thing() -> u32 {
225 fn macro_expand_match_ast() {
228 macro_rules! match_ast {
229 (match $node:ident { $($tt:tt)* }) => { match_ast!(match ($node) { $($tt)* }) };
230 (match ($node:expr) {
231 $( ast::$ast:ident($it:ident) => $res:block, )*
232 _ => $catch_all:expr $(,)?
234 $( if let Some($it) = ast::$ast::cast($node.clone()) $res else )*
242 ast::TraitDef(it) => {},
243 ast::ImplDef(it) => {},
252 if let Some(it) = ast::TraitDef::cast(container.clone()){}
253 else if let Some(it) = ast::ImplDef::cast(container.clone()){}
264 fn macro_expand_match_ast_inside_let_statement() {
267 macro_rules! match_ast {
268 (match $node:ident { $($tt:tt)* }) => { match_ast!(match ($node) { $($tt)* }) };
269 (match ($node:expr) {}) => {{}};
274 let res = mat$0ch_ast! { match c {}};
287 fn macro_expand_inner_macro_fail_to_expand() {
308 fn macro_expand_with_dollar_crate() {
316 () => {$crate::bar!()};