Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1// SPDX-License-Identifier: Apache-2.0 OR MIT
2
3use proc_macro2::{Delimiter, TokenStream, TokenTree};
4use std::hash::{Hash, Hasher};
5
6pub(crate) struct TokenTreeHelper<'a>(pub &'a TokenTree);
7
8impl<'a> PartialEq for TokenTreeHelper<'a> {
9 fn eq(&self, other: &Self) -> bool {
10 use proc_macro2::Spacing;
11
12 match (self.0, other.0) {
13 (TokenTree::Group(g1), TokenTree::Group(g2)) => {
14 match (g1.delimiter(), g2.delimiter()) {
15 (Delimiter::Parenthesis, Delimiter::Parenthesis)
16 | (Delimiter::Brace, Delimiter::Brace)
17 | (Delimiter::Bracket, Delimiter::Bracket)
18 | (Delimiter::None, Delimiter::None) => {}
19 _ => return false,
20 }
21
22 let s1 = g1.stream().into_iter();
23 let mut s2 = g2.stream().into_iter();
24
25 for item1 in s1 {
26 let item2 = match s2.next() {
27 Some(item) => item,
28 None => return false,
29 };
30 if TokenTreeHelper(&item1) != TokenTreeHelper(&item2) {
31 return false;
32 }
33 }
34 s2.next().is_none()
35 }
36 (TokenTree::Punct(o1), TokenTree::Punct(o2)) => {
37 o1.as_char() == o2.as_char()
38 && match (o1.spacing(), o2.spacing()) {
39 (Spacing::Alone, Spacing::Alone) | (Spacing::Joint, Spacing::Joint) => true,
40 _ => false,
41 }
42 }
43 (TokenTree::Literal(l1), TokenTree::Literal(l2)) => l1.to_string() == l2.to_string(),
44 (TokenTree::Ident(s1), TokenTree::Ident(s2)) => s1 == s2,
45 _ => false,
46 }
47 }
48}
49
50impl<'a> Hash for TokenTreeHelper<'a> {
51 fn hash<H: Hasher>(&self, h: &mut H) {
52 use proc_macro2::Spacing;
53
54 match self.0 {
55 TokenTree::Group(g) => {
56 0u8.hash(h);
57 match g.delimiter() {
58 Delimiter::Parenthesis => 0u8.hash(h),
59 Delimiter::Brace => 1u8.hash(h),
60 Delimiter::Bracket => 2u8.hash(h),
61 Delimiter::None => 3u8.hash(h),
62 }
63
64 for item in g.stream() {
65 TokenTreeHelper(&item).hash(h);
66 }
67 0xFFu8.hash(h); // terminator w/ a variant we don't normally hash
68 }
69 TokenTree::Punct(op) => {
70 1u8.hash(h);
71 op.as_char().hash(h);
72 match op.spacing() {
73 Spacing::Alone => 0u8.hash(h),
74 Spacing::Joint => 1u8.hash(h),
75 }
76 }
77 TokenTree::Literal(lit) => (2u8, lit.to_string()).hash(h),
78 TokenTree::Ident(word) => (3u8, word).hash(h),
79 }
80 }
81}
82
83pub(crate) struct TokenStreamHelper<'a>(pub &'a TokenStream);
84
85impl<'a> PartialEq for TokenStreamHelper<'a> {
86 fn eq(&self, other: &Self) -> bool {
87 let left = self.0.clone().into_iter().collect::<Vec<_>>();
88 let right = other.0.clone().into_iter().collect::<Vec<_>>();
89 if left.len() != right.len() {
90 return false;
91 }
92 for (a, b) in left.into_iter().zip(right) {
93 if TokenTreeHelper(&a) != TokenTreeHelper(&b) {
94 return false;
95 }
96 }
97 true
98 }
99}
100
101impl<'a> Hash for TokenStreamHelper<'a> {
102 fn hash<H: Hasher>(&self, state: &mut H) {
103 let tts = self.0.clone().into_iter().collect::<Vec<_>>();
104 tts.len().hash(state);
105 for tt in tts {
106 TokenTreeHelper(&tt).hash(state);
107 }
108 }
109}