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
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
|
use std::num::NonZero;
use rustc_abi::Align;
use rustc_ast::token::CommentKind;
use rustc_ast::{AttrStyle, IntTy, UintTy};
use rustc_ast_pretty::pp::Printer;
use rustc_span::hygiene::Transparency;
use rustc_span::{ErrorGuaranteed, Ident, Span, Symbol};
use rustc_target::spec::SanitizerSet;
use thin_vec::ThinVec;
use crate::limit::Limit;
/// This trait is used to print attributes in `rustc_hir_pretty`.
///
/// For structs and enums it can be derived using [`rustc_macros::PrintAttribute`].
/// The output will look a lot like a `Debug` implementation, but fields of several types
/// like [`Span`]s and empty tuples, are gracefully skipped so they don't clutter the
/// representation much.
pub trait PrintAttribute {
/// Whether or not this will render as something meaningful, or if it's skipped
/// (which will force the containing struct to also skip printing a comma
/// and the field name).
fn should_render(&self) -> bool;
fn print_attribute(&self, p: &mut Printer);
}
impl PrintAttribute for u128 {
fn should_render(&self) -> bool {
true
}
fn print_attribute(&self, p: &mut Printer) {
p.word(self.to_string())
}
}
impl<T: PrintAttribute> PrintAttribute for &T {
fn should_render(&self) -> bool {
T::should_render(self)
}
fn print_attribute(&self, p: &mut Printer) {
T::print_attribute(self, p)
}
}
impl<T: PrintAttribute> PrintAttribute for Option<T> {
fn should_render(&self) -> bool {
self.as_ref().is_some_and(|x| x.should_render())
}
fn print_attribute(&self, p: &mut Printer) {
if let Some(i) = self {
T::print_attribute(i, p)
}
}
}
impl<T: PrintAttribute> PrintAttribute for ThinVec<T> {
fn should_render(&self) -> bool {
self.is_empty() || self[0].should_render()
}
fn print_attribute(&self, p: &mut Printer) {
let mut last_printed = false;
p.word("[");
for i in self {
if last_printed {
p.word_space(",");
}
i.print_attribute(p);
last_printed = i.should_render();
}
p.word("]");
}
}
macro_rules! print_skip {
($($t: ty),* $(,)?) => {$(
impl PrintAttribute for $t {
fn should_render(&self) -> bool { false }
fn print_attribute(&self, _: &mut Printer) { }
})*
};
}
macro_rules! print_disp {
($($t: ty),* $(,)?) => {$(
impl PrintAttribute for $t {
fn should_render(&self) -> bool { true }
fn print_attribute(&self, p: &mut Printer) {
p.word(format!("{}", self));
}
}
)*};
}
macro_rules! print_debug {
($($t: ty),* $(,)?) => {$(
impl PrintAttribute for $t {
fn should_render(&self) -> bool { true }
fn print_attribute(&self, p: &mut Printer) {
p.word(format!("{:?}", self));
}
}
)*};
}
macro_rules! print_tup {
(num_should_render $($ts: ident)*) => { 0 $(+ $ts.should_render() as usize)* };
() => {};
($t: ident $($ts: ident)*) => {
#[allow(non_snake_case, unused)]
impl<$t: PrintAttribute, $($ts: PrintAttribute),*> PrintAttribute for ($t, $($ts),*) {
fn should_render(&self) -> bool {
let ($t, $($ts),*) = self;
print_tup!(num_should_render $t $($ts)*) != 0
}
fn print_attribute(&self, p: &mut Printer) {
let ($t, $($ts),*) = self;
let parens = print_tup!(num_should_render $t $($ts)*) > 1;
if parens {
p.popen();
}
let mut printed_anything = $t.should_render();
$t.print_attribute(p);
$(
if $ts.should_render() {
if printed_anything {
p.word_space(",");
}
printed_anything = true;
}
$ts.print_attribute(p);
)*
if parens {
p.pclose();
}
}
}
print_tup!($($ts)*);
};
}
print_tup!(A B C D E F G H);
print_skip!(Span, (), ErrorGuaranteed);
print_disp!(u16, bool, NonZero<u32>, Limit);
print_debug!(
Symbol,
Ident,
UintTy,
IntTy,
Align,
AttrStyle,
CommentKind,
Transparency,
SanitizerSet,
);
|
