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
extern crate proc_macro;
#[macro_use]
extern crate nom;
#[macro_use]
extern crate quote;
use proc_macro::TokenStream;
use syn::visit::Visit;
mod generator;
mod parser;
#[proc_macro_derive(Escape, attributes(escape))]
pub fn derive(input: TokenStream) -> TokenStream {
let ast: &syn::DeriveInput = &syn::parse(input).unwrap();
build(ast).parse().unwrap()
}
fn build(ast: &syn::DeriveInput) -> String {
let (avx, pairs, print, simd) = visit_derive(ast);
let code = generator::generate(&parser::parse(&pairs), simd, avx);
if print {
eprintln!("{}", code);
}
code
}
fn visit_derive(i: &syn::DeriveInput) -> Struct {
StructBuilder::default().build(i)
}
type Struct = (bool, String, bool, bool);
struct StructBuilder {
avx: bool,
pairs: Option<String>,
print: bool,
simd: bool,
}
impl Default for StructBuilder {
fn default() -> Self {
StructBuilder {
avx: true,
pairs: None,
print: false,
simd: true,
}
}
}
impl StructBuilder {
fn build(mut self, syn::DeriveInput { attrs, .. }: &syn::DeriveInput) -> Struct {
for i in attrs {
self.visit_meta(&i.parse_meta().expect("valid meta attributes"));
}
(
self.avx,
self.pairs.expect("Need pairs attribute"),
self.print,
self.simd,
)
}
}
impl<'a> Visit<'a> for StructBuilder {
fn visit_meta_list(&mut self, syn::MetaList { path, nested, .. }: &'a syn::MetaList) {
if path.is_ident("escape") {
use syn::punctuated::Punctuated;
for el in Punctuated::pairs(nested) {
let it = el.value();
self.visit_nested_meta(it)
}
}
}
fn visit_meta_name_value(
&mut self,
syn::MetaNameValue { path, lit, .. }: &'a syn::MetaNameValue,
) {
if path.is_ident("avx") {
if let syn::Lit::Bool(s) = lit {
self.avx = s.value
} else {
panic!("attribute avx value must be boolean")
}
} else if path.is_ident("pairs") {
if let syn::Lit::Str(s) = lit {
self.pairs = Some(s.value());
} else {
panic!("attribute pairs must be string literal");
}
} else if path.is_ident("print") {
if let syn::Lit::Bool(s) = lit {
self.print = s.value;
} else {
panic!("attribute print must be boolean");
}
} else if path.is_ident("simd") {
if let syn::Lit::Bool(s) = lit {
self.simd = s.value;
} else {
panic!("attribute simd must be boolean");
}
} else {
panic!("invalid attribute '{:?}'", path.get_ident())
}
}
}