xref: /aosp_15_r20/external/cronet/third_party/rust/chromium_crates_io/vendor/syn-2.0.55/src/macros.rs (revision 6777b5387eb2ff775bb5750e3f5d96f37fb7352b) 
1 #[cfg_attr(
2     not(any(feature = "full", feature = "derive")),
3     allow(unknown_lints, unused_macro_rules)
4 )]
5 macro_rules! ast_struct {
6     (
7         $(#[$attr:meta])*
8         $pub:ident $struct:ident $name:ident #full $body:tt
9     ) => {
10         check_keyword_matches!(pub $pub);
11         check_keyword_matches!(struct $struct);
12 
13         #[cfg(feature = "full")]
14         $(#[$attr])* $pub $struct $name $body
15 
16         #[cfg(not(feature = "full"))]
17         $(#[$attr])* $pub $struct $name {
18             _noconstruct: ::std::marker::PhantomData<::proc_macro2::Span>,
19         }
20 
21         #[cfg(all(not(feature = "full"), feature = "printing"))]
22         impl ::quote::ToTokens for $name {
23             fn to_tokens(&self, _: &mut ::proc_macro2::TokenStream) {
24                 unreachable!()
25             }
26         }
27     };
28 
29     (
30         $(#[$attr:meta])*
31         $pub:ident $struct:ident $name:ident $body:tt
32     ) => {
33         check_keyword_matches!(pub $pub);
34         check_keyword_matches!(struct $struct);
35 
36         $(#[$attr])* $pub $struct $name $body
37     };
38 }
39 
40 #[cfg(any(feature = "full", feature = "derive"))]
41 macro_rules! ast_enum {
42     (
43         $(#[$enum_attr:meta])*
44         $pub:ident $enum:ident $name:ident $body:tt
45     ) => {
46         check_keyword_matches!(pub $pub);
47         check_keyword_matches!(enum $enum);
48 
49         $(#[$enum_attr])* $pub $enum $name $body
50     };
51 }
52 
53 macro_rules! ast_enum_of_structs {
54     (
55         $(#[$enum_attr:meta])*
56         $pub:ident $enum:ident $name:ident $body:tt
57     ) => {
58         check_keyword_matches!(pub $pub);
59         check_keyword_matches!(enum $enum);
60 
61         $(#[$enum_attr])* $pub $enum $name $body
62 
63         ast_enum_of_structs_impl!($name $body);
64     };
65 }
66 
67 macro_rules! ast_enum_of_structs_impl {
68     (
69         $name:ident {
70             $(
71                 $(#[cfg $cfg_attr:tt])*
72                 $(#[doc $($doc_attr:tt)*])*
73                 $variant:ident $( ($($member:ident)::+) )*,
74             )*
75         }
76     ) => {
77         $($(
78             ast_enum_from_struct!($name::$variant, $($member)::+);
79         )*)*
80 
81         #[cfg(feature = "printing")]
82         generate_to_tokens! {
83             ()
84             tokens
85             $name {
86                 $(
87                     $(#[cfg $cfg_attr])*
88                     $(#[doc $($doc_attr)*])*
89                     $variant $($($member)::+)*,
90                 )*
91             }
92         }
93     };
94 }
95 
96 macro_rules! ast_enum_from_struct {
97     // No From<TokenStream> for verbatim variants.
98     ($name:ident::Verbatim, $member:ident) => {};
99 
100     ($name:ident::$variant:ident, $member:ident) => {
101         impl From<$member> for $name {
102             fn from(e: $member) -> $name {
103                 $name::$variant(e)
104             }
105         }
106     };
107 }
108 
109 #[cfg(feature = "printing")]
110 macro_rules! generate_to_tokens {
111     (
112         ($($arms:tt)*) $tokens:ident $name:ident {
113             $(#[cfg $cfg_attr:tt])*
114             $(#[doc $($doc_attr:tt)*])*
115             $variant:ident,
116             $($next:tt)*
117         }
118     ) => {
119         generate_to_tokens!(
120             ($($arms)* $(#[cfg $cfg_attr])* $name::$variant => {})
121             $tokens $name { $($next)* }
122         );
123     };
124 
125     (
126         ($($arms:tt)*) $tokens:ident $name:ident {
127             $(#[cfg $cfg_attr:tt])*
128             $(#[doc $($doc_attr:tt)*])*
129             $variant:ident $member:ident,
130             $($next:tt)*
131         }
132     ) => {
133         generate_to_tokens!(
134             ($($arms)* $(#[cfg $cfg_attr])* $name::$variant(_e) => _e.to_tokens($tokens),)
135             $tokens $name { $($next)* }
136         );
137     };
138 
139     (($($arms:tt)*) $tokens:ident $name:ident {}) => {
140         #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
141         impl ::quote::ToTokens for $name {
142             fn to_tokens(&self, $tokens: &mut ::proc_macro2::TokenStream) {
143                 match self {
144                     $($arms)*
145                 }
146             }
147         }
148     };
149 }
150 
151 // Rustdoc bug: does not respect the doc(hidden) on some items.
152 #[cfg(all(doc, feature = "parsing"))]
153 macro_rules! pub_if_not_doc {
154     ($(#[$m:meta])* $pub:ident $($item:tt)*) => {
155         check_keyword_matches!(pub $pub);
156 
157         $(#[$m])*
158         $pub(crate) $($item)*
159     };
160 }
161 
162 #[cfg(all(not(doc), feature = "parsing"))]
163 macro_rules! pub_if_not_doc {
164     ($(#[$m:meta])* $pub:ident $($item:tt)*) => {
165         check_keyword_matches!(pub $pub);
166 
167         $(#[$m])*
168         $pub $($item)*
169     };
170 }
171 
172 macro_rules! check_keyword_matches {
173     (enum enum) => {};
174     (pub pub) => {};
175     (struct struct) => {};
176 }
177