-
Notifications
You must be signed in to change notification settings - Fork 0
/
lib.rs
213 lines (203 loc) · 6.61 KB
/
lib.rs
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
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
extern crate proc_macro;
use proc_macro::TokenStream;
use quote::quote;
use syn::parse_macro_input;
use syn::spanned::Spanned;
#[proc_macro_attribute]
pub fn globals_struct_field(_attr: TokenStream, _item: TokenStream) -> TokenStream {
TokenStream::new()
}
#[proc_macro_attribute]
pub fn globals_struct_use(_attr: TokenStream, _item: TokenStream) -> TokenStream {
TokenStream::new()
}
#[proc_macro_attribute]
pub fn globals_struct(_attr: TokenStream, item: TokenStream) -> TokenStream {
let syn::ItemMod {
vis: mod_vis,
ident: mod_name,
content: mod_content,
..
} = parse_macro_input!(item as syn::ItemMod);
let mod_items = match mod_content {
None => {
return syn::Error::new(
syn::export::Span::call_site(),
"Module content should be provided.",
)
.to_compile_error()
.into();
}
Some((_, contents)) => contents,
};
let mut field_vises = vec![];
let mut field_names = vec![];
let mut field_tys = vec![];
let mut field_exprs = vec![];
let mut use_vises = vec![];
let mut use_leading_colons = vec![];
let mut use_usetrees = vec![];
if let Err(e) = recursive_process_items(
&mod_name,
&mod_items,
(
&mut field_vises,
&mut field_names,
&mut field_tys,
&mut field_exprs,
),
(&mut use_vises, &mut use_leading_colons, &mut use_usetrees),
) {
return e.to_compile_error().into();
}
let ts = quote! {
#mod_vis struct #mod_name {
#(#field_vises #field_names : #field_tys ,)*
}
impl ::core::default::Default for #mod_name {
fn default() -> Self {
#mod_name {
#(#field_names : #field_exprs ,)*
}
}
}
#(#use_vises use #use_leading_colons #use_usetrees;)*
};
ts.into()
}
fn recursive_process_items(
mod_name: &syn::Ident,
mod_items: &[syn::Item],
(field_vises, field_names, field_tys, field_exprs): (
&mut Vec<syn::Visibility>,
&mut Vec<syn::Ident>,
&mut Vec<Box<syn::Type>>,
&mut Vec<Box<syn::Expr>>,
),
(use_vises, use_leading_colons, use_usetrees): (
&mut Vec<syn::Visibility>,
&mut Vec<Option<syn::Token![::]>>,
&mut Vec<syn::UseTree>,
),
) -> syn::Result<()> {
for item in mod_items {
let item_span = item.span();
if let syn::Item::Static(syn::ItemStatic {
vis: static_vis,
attrs: static_attrs,
ident: static_name,
ty: static_ty,
expr: static_initializer,
..
}) = item
{
let target =
globals_struct_attr_target(&static_attrs, item_span, "globals_struct_field")?;
if let Some(target) = target {
if target == *mod_name {
field_vises.push(static_vis.clone());
field_names.push(static_name.clone());
field_tys.push(static_ty.clone());
field_exprs.push(static_initializer.clone());
}
}
} else if let syn::Item::Use(syn::ItemUse {
vis: use_vis,
attrs: use_attrs,
leading_colon: use_leading_colon,
tree: use_usetree,
..
}) = item
{
let target = globals_struct_attr_target(&use_attrs, item_span, "globals_struct_use")?;
if let Some(target) = target {
if target == *mod_name {
if use_usetrees.iter().all(|existing| existing != use_usetree) {
use_vises.push(use_vis.clone());
use_leading_colons.push(use_leading_colon.clone());
use_usetrees.push(use_usetree.clone());
}
}
}
} else if let syn::Item::Macro(syn::ItemMacro { mac, .. }) = item {
let mac_span = mac.span();
if mac
.path
.get_ident()
.map(|v| *v == "include")
.unwrap_or(false)
{
let filepath = mac.parse_body::<syn::LitStr>()?;
let file_content = std::fs::read_to_string(filepath.value())
.map_err(|e| syn::Error::new(mac_span, e))?;
let file = syn::parse_file(&file_content)?;
recursive_process_items(
mod_name,
&file.items,
(field_vises, field_names, field_tys, field_exprs),
(use_vises, use_leading_colons, use_usetrees),
)?;
}
}
}
Ok(())
}
fn globals_struct_attr_target(
attrs: &[syn::Attribute],
span: syn::export::Span,
expected_attr_name: &'static str,
) -> syn::Result<Option<syn::Ident>> {
let mut found_attr = None;
for attr in attrs {
if let Some(attr_ident) = get_path_last_ident(&attr.path) {
if *attr_ident == expected_attr_name {
if found_attr.is_some() {
return Err(syn::Error::new(
span,
"Attribute `globals_struct_field` or `globals_struct_use` should not be specified more than once on an item.",
));
}
found_attr = Some(attr);
}
}
}
let found_attr = if let Some(attr) = found_attr {
attr
} else {
return Ok(None);
};
let meta = found_attr.parse_meta()?;
let target_path = match get_meta_sole_path(&meta) {
Some(path) => path,
None => {
return Err(syn::Error::new(
span,
"Attribute `globals_struct_field` or `globals_struct_use` should be specified in the form #[globals_struct_field(Globals)] or #[globals_struct_use(Globals)].",
));
}
};
Ok(get_path_last_ident(target_path).cloned())
}
fn get_meta_sole_path(meta: &syn::Meta) -> Option<&syn::Path> {
let list = if let syn::Meta::List(list) = meta {
list
} else {
return None;
};
if list.nested.len() != 1 {
return None;
}
if let syn::NestedMeta::Meta(syn::Meta::Path(inner_path)) = &list.nested[0] {
Some(inner_path)
} else {
None
}
}
fn get_path_last_ident(path: &syn::Path) -> Option<&syn::Ident> {
let last_segment = path.segments.last()?;
if let syn::PathArguments::None = last_segment.arguments {
Some(&last_segment.ident)
} else {
None
}
}