language-servers/rust-analyzer
1
0
Fork 0
mirror of https://github.com/rust-lang/rust-analyzer.git synced 2025-09-28 21:05:02 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 4

Rewrite #[derive] removal to be based on AST

Browse source
This commit is contained in:
Jonas Schievink 2021-04-09 14:10:54 +02:00
parent c0dd36fd42
commit 7e78aebc8f
4 changed files with 92 additions and 105 deletions
Download patch file Download diff file Expand all files Collapse all files

102
crates/hir_expand/src/proc_macro.rs
View file

@ -2,7 +2,6 @@
use crate::db::AstDatabase;
use base_db::{CrateId, ProcMacroId};
use tt::buffer::{Cursor, TokenBuffer};
#[derive(Debug, Clone, Copy, Eq, PartialEq, Hash)]
pub struct ProcMacroExpander {
@ -44,9 +43,6 @@ impl ProcMacroExpander {
.clone()
.ok_or_else(|| err!("No derive macro found."))?;
let tt = remove_derive_attrs(tt)
.ok_or_else(|| err!("Fail to remove derive for custom derive"))?;
// Proc macros have access to the environment variables of the invoking crate.
let env = &krate_graph[calling_crate].env;
@ -56,101 +52,3 @@ impl ProcMacroExpander {
}
}
}
fn eat_punct(cursor: &mut Cursor, c: char) -> bool {
if let Some(tt::buffer::TokenTreeRef::Leaf(tt::Leaf::Punct(punct), _)) = cursor.token_tree() {
if punct.char == c {
*cursor = cursor.bump();
return true;
}
}
false
}
fn eat_subtree(cursor: &mut Cursor, kind: tt::DelimiterKind) -> bool {
if let Some(tt::buffer::TokenTreeRef::Subtree(subtree, _)) = cursor.token_tree() {
if Some(kind) == subtree.delimiter_kind() {
*cursor = cursor.bump_subtree();
return true;
}
}
false
}
fn eat_ident(cursor: &mut Cursor, t: &str) -> bool {
if let Some(tt::buffer::TokenTreeRef::Leaf(tt::Leaf::Ident(ident), _)) = cursor.token_tree() {
if t == ident.text.as_str() {
*cursor = cursor.bump();
return true;
}
}
false
}
fn remove_derive_attrs(tt: &tt::Subtree) -> Option<tt::Subtree> {
let buffer = TokenBuffer::from_tokens(&tt.token_trees);
let mut p = buffer.begin();
let mut result = tt::Subtree::default();
while !p.eof() {
let curr = p;
if eat_punct(&mut p, '#') {
eat_punct(&mut p, '!');
let parent = p;
if eat_subtree(&mut p, tt::DelimiterKind::Bracket) {
if eat_ident(&mut p, "derive") {
p = parent.bump();
continue;
}
}
}
result.token_trees.push(curr.token_tree()?.cloned());
p = curr.bump();
}
Some(result)
}
#[cfg(test)]
mod tests {
use super::*;
use test_utils::assert_eq_text;
#[test]
fn test_remove_derive_attrs() {
let tt = mbe::parse_to_token_tree(
r#"
#[allow(unused)]
#[derive(Copy)]
#[derive(Hello)]
struct A {
bar: u32
}
"#,
)
.unwrap()
.0;
let result = format!("{:#?}", remove_derive_attrs(&tt).unwrap());
assert_eq_text!(
r#"
SUBTREE $
PUNCH # [alone] 0
SUBTREE [] 1
IDENT allow 2
SUBTREE () 3
IDENT unused 4
IDENT struct 15
IDENT A 16
SUBTREE {} 17
IDENT bar 18
PUNCH : [alone] 19
IDENT u32 20
"#
.trim(),
&result
);
}
}