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
|
use syn;
use quote::ToTokens;
use proc_macro2;
const PREFIX: &'static str = "pgp_";
/// Derives the C type from the Rust type.
///
/// Returns the corresponding C type, and whether or not that type is
/// a pointer type.
fn ident2c(ident: &syn::Ident) -> (String, bool) {
let ident_string = ident.to_string();
// Special cases :(
match ident_string.as_str() {
"KeyID" => return ("pgp_keyid_t".into(), true),
"CertBuilder" => return ("pgp_cert_builder_t".into(), true),
"UserID" => return ("pgp_userid_t".into(), true),
"UserIDBundle" => return ("pgp_user_id_bundle_t".into(), true),
"UserIDBundleIter" =>
return ("pgp_user_id_bundle_iter_t".into(), true),
// Types from the libc crate.
"c_void" => return ("void".into(), false),
"c_char" => return ("char".into(), false),
"c_int" => return ("int".into(), false),
"c_uint" => return ("uint".into(), false),
"bool" => return ("bool".into(), false),
"size_t" | "ssize_t" | "time_t" |
"int8_t" | "int16_t" | "int32_t" | "int64_t" |
"uint8_t" | "uint16_t" | "uint32_t" | "uint64_t"
=> return (ident_string.clone(), false),
// Primitive types.
"u8" => return ("uint8_t".into(), false),
"u16" => return ("uint16_t".into(), false),
"u32" => return ("uint32_t".into(), false),
"u64" => return ("uint64_t".into(), false),
"i8" => return ("int8_t".into(), false),
"i16" => return ("int16_t".into(), false),
"i32" => return ("int32_t".into(), false),
"i64" => return ("int64_t".into(), false),
_ => (),
}
let mut s = String::new();
s += PREFIX;
let mut last_was_uppercase = false;
for (i, c) in ident_string.chars().enumerate() {
if c.is_uppercase() {
if ! last_was_uppercase && i > 0 {
s += "_";
}
s += &c.to_lowercase().to_string();
} else {
s += &c.to_string();
}
last_was_uppercase = c.is_uppercase();
}
s += "_t";
(s, true)
}
fn type2c<T: ToTokens>(typ: T) -> String {
let mut tokens = proc_macro2::TokenStream::new();
typ.to_tokens(&mut tokens);
let mut c_typ = String::new();
let mut is_mutable = false;
let mut is_pointer = 0;
let mut ident = None;
for tok in tokens {
use proc_macro2::TokenTree::*;
if false {
eprintln!("mut: {}, ptr: {}, ident: {:?}, tok: {:?}",
is_mutable, is_pointer, ident, tok);
}
match tok {
Ident(ref i) => {
let i_ = format!("{}", i);
match i_.as_str() {
"mut" => is_mutable = true,
"const" => is_mutable = false,
"Option" => (),
"Maybe" => {
is_pointer += 1;
is_mutable = true;
}
_ => {
if is_pointer > 0 && ! is_mutable {
c_typ += "const ";
}
ident = Some(i.clone());
},
}
},
Punct(ref p) => {
if ident.is_some() && p.as_char() != ':' {
// We already found the ident, now skip the <...>.
break;
}
match p.as_char() {
'*' | '&' => {
is_pointer += 1;
},
_ => (),
}
//eprintln!("{:?}", p);
},
Literal(ref l) => panic!("Unexpected {:?}", l),
Group(ref g) => panic!("Unexpected {:?}", g),
}
}
if let Some(c_ident) = ident {
let (c_ident, is_pointer_type) = ident2c(&c_ident);
if is_pointer_type {
is_pointer -= 1;
}
c_typ += &c_ident;
} else {
panic!();
}
c_typ.push(' ');
while is_pointer > 0 {
c_typ.push('*');
is_pointer -= 1;
}
//eprintln!("==> {:?} // {}", c_typ, is_pointer);
c_typ
}
pub fn rust2c(fun: &syn::ItemFn) -> String {
let return_type = match &fun.sig.output {
syn::ReturnType::Default => "void".into(),
syn::ReturnType::Type(_, ref typ) => type2c(typ).trim_end().to_string(),
};
let fun_ident = format!("{}", fun.sig.ident);
let mut s = String::new();
s += &format!("{}\n{} (", return_type, fun_ident);
let indent = fun_ident.len() + 2;
for (i, arg) in fun.sig.inputs.iter().enumerate() {
// All but the first line need to be indented.
if i > 0 {
for _ in 0..indent {
s.push(' ');
}
}
match arg {
&syn::FnArg::Typed(ref cap) => {
let pat_ident = match *cap.pat {
syn::Pat::Ident(ref i) => i,
_ => unimplemented!(),
};
s += &format!("{}{}", type2c(&cap.ty), pat_ident.ident);
},
_ => (),
}
// All but the last one need a comma.
if i < fun.sig.inputs.len() - 1 {
s += ",\n";
}
}
s += ");";
s
}
|