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 expanded = sema.expand_attr_macro(&item);
38 if expanded.is_some() {
39 // FIXME: add the macro name
40 // FIXME: make this recursive too
41 name = Some("?".to_string());
46 if let Some(mac) = ast::MacroCall::cast(node) {
47 name = Some(mac.path()?.segment()?.name_ref()?.to_string());
48 expanded = expand_macro_recur(&sema, &mac);
54 // macro expansion may lose all white space information
55 // But we hope someday we can use ra_fmt for that
56 let expansion = insert_whitespaces(expanded?);
57 Some(ExpandedMacro { name: name?, expansion })
60 fn expand_macro_recur(
61 sema: &Semantics<RootDatabase>,
62 macro_call: &ast::MacroCall,
63 ) -> Option<SyntaxNode> {
64 let expanded = sema.expand(macro_call)?.clone_for_update();
66 let children = expanded.descendants().filter_map(ast::MacroCall::cast);
67 let mut replacements = Vec::new();
69 for child in children {
70 if let Some(new_node) = expand_macro_recur(sema, &child) {
71 // check if the whole original syntax is replaced
72 if expanded == *child.syntax() {
73 return Some(new_node);
75 replacements.push((child, new_node));
79 replacements.into_iter().rev().for_each(|(old, new)| ted::replace(old.syntax(), new));
83 // FIXME: It would also be cool to share logic here and in the mbe tests,
84 // which are pretty unreadable at the moment.
85 fn insert_whitespaces(syn: SyntaxNode) -> String {
86 let mut res = String::new();
87 let mut token_iter = syn
88 .preorder_with_tokens()
90 if let WalkEvent::Enter(NodeOrToken::Token(token)) = event {
99 let mut last: Option<SyntaxKind> = None;
101 while let Some(token) = token_iter.next() {
102 let mut is_next = |f: fn(SyntaxKind) -> bool, default| -> bool {
103 token_iter.peek().map(|it| f(it.kind())).unwrap_or(default)
106 |f: fn(SyntaxKind) -> bool, default| -> bool { last.map(f).unwrap_or(default) };
109 k if is_text(k) && is_next(|it| !it.is_punct(), true) => {
110 res.push_str(token.text());
113 L_CURLY if is_next(|it| it != R_CURLY, true) => {
115 if is_last(is_text, false) {
119 res.extend(iter::repeat(" ").take(2 * indent));
121 R_CURLY if is_last(|it| it != L_CURLY, true) => {
122 indent = indent.saturating_sub(1);
124 res.extend(iter::repeat(" ").take(2 * indent));
129 res.extend(iter::repeat(" ").take(2 * indent));
131 LIFETIME_IDENT if is_next(|it| it == IDENT, true) => {
132 res.push_str(token.text());
137 res.extend(iter::repeat(" ").take(2 * indent));
139 T![->] => res.push_str(" -> "),
140 T![=] => res.push_str(" = "),
141 T![=>] => res.push_str(" => "),
142 _ => res.push_str(token.text()),
145 last = Some(token.kind());
150 fn is_text(k: SyntaxKind) -> bool {
151 k.is_keyword() || k.is_literal() || k == IDENT
157 use expect_test::{expect, Expect};
161 fn check(ra_fixture: &str, expect: Expect) {
162 let (analysis, pos) = fixture::position(ra_fixture);
163 let expansion = analysis.expand_macro(pos).unwrap().unwrap();
164 let actual = format!("{}\n{}", expansion.name, expansion.expansion);
165 expect.assert_eq(&actual);
169 fn macro_expand_recursive_expansion() {
191 fn macro_expand_multiple_lines() {
196 fn some_thing() -> u32 {
206 fn some_thing() -> u32 {
214 fn macro_expand_match_ast() {
217 macro_rules! match_ast {
218 (match $node:ident { $($tt:tt)* }) => { match_ast!(match ($node) { $($tt)* }) };
219 (match ($node:expr) {
220 $( ast::$ast:ident($it:ident) => $res:block, )*
221 _ => $catch_all:expr $(,)?
223 $( if let Some($it) = ast::$ast::cast($node.clone()) $res else )*
231 ast::TraitDef(it) => {},
232 ast::ImplDef(it) => {},
241 if let Some(it) = ast::TraitDef::cast(container.clone()){}
242 else if let Some(it) = ast::ImplDef::cast(container.clone()){}
253 fn macro_expand_match_ast_inside_let_statement() {
256 macro_rules! match_ast {
257 (match $node:ident { $($tt:tt)* }) => { match_ast!(match ($node) { $($tt)* }) };
258 (match ($node:expr) {}) => {{}};
263 let res = mat$0ch_ast! { match c {}};
276 fn macro_expand_inner_macro_fail_to_expand() {
297 fn macro_expand_with_dollar_crate() {
305 () => {$crate::bar!()};