4 use ide_db::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 = file.syntax().token_at_offset(position.offset).left_biased()?;
30 let mut expanded = None;
32 for node in tok.ancestors() {
33 if let Some(item) = ast::Item::cast(node.clone()) {
34 expanded = sema.expand_attr_macro(&item);
35 if expanded.is_some() {
36 // FIXME: add the macro name
37 // FIXME: make this recursive too
38 name = Some("?".to_string());
43 if let Some(mac) = ast::MacroCall::cast(node) {
44 name = Some(mac.path()?.segment()?.name_ref()?.to_string());
45 expanded = expand_macro_recur(&sema, &mac);
51 // macro expansion may lose all white space information
52 // But we hope someday we can use ra_fmt for that
53 let expansion = insert_whitespaces(expanded?);
54 Some(ExpandedMacro { name: name?, expansion })
57 fn expand_macro_recur(
58 sema: &Semantics<RootDatabase>,
59 macro_call: &ast::MacroCall,
60 ) -> Option<SyntaxNode> {
61 let expanded = sema.expand(macro_call)?.clone_for_update();
63 let children = expanded.descendants().filter_map(ast::MacroCall::cast);
64 let mut replacements = Vec::new();
66 for child in children {
67 if let Some(new_node) = expand_macro_recur(sema, &child) {
68 // check if the whole original syntax is replaced
69 if expanded == *child.syntax() {
70 return Some(new_node);
72 replacements.push((child, new_node));
76 replacements.into_iter().rev().for_each(|(old, new)| ted::replace(old.syntax(), new));
80 // FIXME: It would also be cool to share logic here and in the mbe tests,
81 // which are pretty unreadable at the moment.
82 fn insert_whitespaces(syn: SyntaxNode) -> String {
83 let mut res = String::new();
84 let mut token_iter = syn
85 .preorder_with_tokens()
87 if let WalkEvent::Enter(NodeOrToken::Token(token)) = event {
96 let mut last: Option<SyntaxKind> = None;
98 while let Some(token) = token_iter.next() {
99 let mut is_next = |f: fn(SyntaxKind) -> bool, default| -> bool {
100 token_iter.peek().map(|it| f(it.kind())).unwrap_or(default)
103 |f: fn(SyntaxKind) -> bool, default| -> bool { last.map(f).unwrap_or(default) };
106 k if is_text(k) && is_next(|it| !it.is_punct(), true) => {
107 res.push_str(token.text());
110 L_CURLY if is_next(|it| it != R_CURLY, true) => {
112 if is_last(is_text, false) {
116 res.extend(iter::repeat(" ").take(2 * indent));
118 R_CURLY if is_last(|it| it != L_CURLY, true) => {
119 indent = indent.saturating_sub(1);
121 res.extend(iter::repeat(" ").take(2 * indent));
126 res.extend(iter::repeat(" ").take(2 * indent));
128 LIFETIME_IDENT if is_next(|it| it == IDENT, true) => {
129 res.push_str(token.text());
134 res.extend(iter::repeat(" ").take(2 * indent));
136 T![->] => res.push_str(" -> "),
137 T![=] => res.push_str(" = "),
138 T![=>] => res.push_str(" => "),
139 _ => res.push_str(token.text()),
142 last = Some(token.kind());
147 fn is_text(k: SyntaxKind) -> bool {
148 k.is_keyword() || k.is_literal() || k == IDENT
154 use expect_test::{expect, Expect};
158 fn check(ra_fixture: &str, expect: Expect) {
159 let (analysis, pos) = fixture::position(ra_fixture);
160 let expansion = analysis.expand_macro(pos).unwrap().unwrap();
161 let actual = format!("{}\n{}", expansion.name, expansion.expansion);
162 expect.assert_eq(&actual);
166 fn macro_expand_recursive_expansion() {
188 fn macro_expand_multiple_lines() {
193 fn some_thing() -> u32 {
203 fn some_thing() -> u32 {
211 fn macro_expand_match_ast() {
214 macro_rules! match_ast {
215 (match $node:ident { $($tt:tt)* }) => { match_ast!(match ($node) { $($tt)* }) };
216 (match ($node:expr) {
217 $( ast::$ast:ident($it:ident) => $res:block, )*
218 _ => $catch_all:expr $(,)?
220 $( if let Some($it) = ast::$ast::cast($node.clone()) $res else )*
228 ast::TraitDef(it) => {},
229 ast::ImplDef(it) => {},
238 if let Some(it) = ast::TraitDef::cast(container.clone()){}
239 else if let Some(it) = ast::ImplDef::cast(container.clone()){}
250 fn macro_expand_match_ast_inside_let_statement() {
253 macro_rules! match_ast {
254 (match $node:ident { $($tt:tt)* }) => { match_ast!(match ($node) { $($tt)* }) };
255 (match ($node:expr) {}) => {{}};
260 let res = mat$0ch_ast! { match c {}};
273 fn macro_expand_inner_macro_fail_to_expand() {
294 fn macro_expand_with_dollar_crate() {
302 () => {$crate::bar!()};