1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
|
//! FIXME: write short doc here
use crate::{db::RootDatabase, FilePosition};
use hir::db::AstDatabase;
use ra_db::SourceDatabase;
use rustc_hash::FxHashMap;
use ra_syntax::{
algo::{find_node_at_offset, replace_descendants},
ast::{self},
AstNode, NodeOrToken, SyntaxKind, SyntaxNode, WalkEvent,
};
fn insert_whitespaces(syn: SyntaxNode) -> String {
let mut res = String::new();
let mut token_iter = syn
.preorder_with_tokens()
.filter_map(|event| {
if let WalkEvent::Enter(NodeOrToken::Token(token)) = event {
Some(token)
} else {
None
}
})
.peekable();
while let Some(token) = token_iter.next() {
res += &token.text().to_string();
if token.kind().is_keyword()
|| token.kind().is_literal()
|| token.kind() == SyntaxKind::IDENT
{
if !token_iter.peek().map(|it| it.kind().is_punct()).unwrap_or(false) {
res += " ";
}
}
}
res
}
fn expand_macro_recur(
db: &RootDatabase,
source: hir::Source<&SyntaxNode>,
macro_call: &ast::MacroCall,
) -> Option<SyntaxNode> {
let analyzer = hir::SourceAnalyzer::new(db, source, None);
let expansion = analyzer.expand(db, ¯o_call)?;
let new_source = expansion.source(db);
let expanded: SyntaxNode = db.parse_or_expand(new_source.file_id)?;
let children = expanded.descendants().filter_map(ast::MacroCall::cast);
let mut replaces = FxHashMap::default();
for child in children.into_iter() {
let source = new_source.with_ast(source.ast);
let new_node = expand_macro_recur(db, source, &child)?;
replaces.insert(child.syntax().clone().into(), new_node.into());
}
Some(replace_descendants(&expanded, &replaces))
}
pub(crate) fn expand_macro(db: &RootDatabase, position: FilePosition) -> Option<(String, String)> {
let parse = db.parse(position.file_id);
let file = parse.tree();
let name_ref = find_node_at_offset::<ast::NameRef>(file.syntax(), position.offset)?;
let mac = name_ref.syntax().ancestors().find_map(ast::MacroCall::cast)?;
let source = hir::Source::new(position.file_id.into(), mac.syntax());
let expanded = expand_macro_recur(db, source, &mac)?;
// FIXME:
// macro expansion may lose all white space information
// But we hope someday we can use ra_fmt for that
let res = insert_whitespaces(expanded);
Some((name_ref.text().to_string(), res))
}
#[cfg(test)]
mod tests {
use crate::mock_analysis::analysis_and_position;
fn check_expand_macro(fixture: &str, expected: (&str, &str)) {
let (analysis, pos) = analysis_and_position(fixture);
let result = analysis.expand_macro(pos).unwrap().unwrap();
assert_eq!(result, (expected.0.to_string(), expected.1.to_string()));
}
#[test]
fn macro_expand_recursive_expansion() {
check_expand_macro(
r#"
//- /lib.rs
macro_rules! bar {
() => { fn b() {} }
}
macro_rules! foo {
() => { bar!(); }
}
macro_rules! baz {
() => { foo!(); }
}
f<|>oo!();
"#,
("foo", "fn b(){}"),
);
}
}
|
