cbindgen 0.1.20

A tool for generating C bindings to Rust code.
Documentation 
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

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

use std::io::Write;

use syn;

use bindgen::annotation::*;
use bindgen::cdecl;
use bindgen::config::{Config, Layout};
use bindgen::ir::*;
use bindgen::library::*;
use bindgen::rename::*;
use bindgen::utilities::*;
use bindgen::writer::*;

#[derive(Debug, Clone)]
pub struct Function {
    pub name: String,
    pub annotations: AnnotationSet,
    pub ret: Type,
    pub args: Vec<(String, Type)>,
    pub extern_decl: bool,
}

impl Function {
    pub fn load(name: String,
                annotations: AnnotationSet,
                decl: &syn::FnDecl,
                extern_decl: bool) -> Result<Function, String>
    {
        let args = decl.inputs.iter()
                              .try_skip_map(|x| x.as_ident_and_type())?;
        let ret = decl.output.as_type()?;

        Ok(Function {
            name: name,
            annotations: annotations,
            ret: ret,
            args: args,
            extern_decl: extern_decl,
        })
    }

    pub fn add_deps(&self, library: &Library, out: &mut DependencyList) {
        self.ret.add_deps(library, out);
        for &(_, ref ty) in &self.args {
            ty.add_deps(library, out);
        }
    }

    pub fn add_monomorphs(&self, library: &Library, out: &mut Monomorphs) {
        self.ret.add_monomorphs(library, out);
        for &(_, ref ty) in &self.args {
            ty.add_monomorphs(library, out);
        }
    }

    pub fn add_specializations(&self, library: &Library, out: &mut SpecializationList) {
        self.ret.add_specializations(library, out);
        for &(_, ref ty) in &self.args {
            ty.add_specializations(library, out);
        }
    }

    pub fn rename_args(&mut self, config: &Config) {
        let rules = [self.annotations.parse_atom::<RenameRule>("rename-all"),
                     config.function.rename_args];

        if let Some(r) = find_first_some(&rules) {
            self.args = self.args.iter()
                                 .map(|x| (r.apply_to_snake_case(&x.0,
                                                                 IdentifierType::FunctionArg),
                                           x.1.clone()))
                                  .collect()
        }
    }

    pub fn mangle_paths(&mut self, monomorphs: &Monomorphs) {
        for &mut (_, ref mut ty) in &mut self.args {
            ty.mangle_paths(monomorphs);
        }
    }
}

impl Source for Function {
    fn write<F: Write>(&self, config: &Config, out: &mut SourceWriter<F>) {
        fn write_1<W: Write>(func: &Function, config: &Config, out: &mut SourceWriter<W>) {
            let prefix = config.function.prefix(&func.annotations);
            let postfix = config.function.postfix(&func.annotations);

            if let Some(ref prefix) = prefix {
                out.write(prefix);
                out.write(" ");
            }
            cdecl::write_func(out, &func, false);
            if let Some(ref postfix) = postfix {
                out.write(" ");
                out.write(postfix);
            }
            out.write(";");
        }

        fn write_2<W: Write>(func: &Function, config: &Config, out: &mut SourceWriter<W>) {
            let prefix = config.function.prefix(&func.annotations);
            let postfix = config.function.postfix(&func.annotations);

            if let Some(ref prefix) = prefix {
                out.write(prefix);
                out.new_line();
            }
            cdecl::write_func(out, &func, true);
            if let Some(ref postfix) = postfix {
                out.new_line();
                out.write(postfix);
            }
            out.write(";");
        };

        let option_1 = out.measure(|out| write_1(self, config, out));

        if (config.function.args == Layout::Auto && option_1 <= config.line_length) ||
           config.function.args == Layout::Horizontal {
            write_1(self, config, out);
        } else {
            write_2(self, config, out);
        }
    }
}

pub trait SynFnArgHelpers {
    fn as_ident_and_type(&self) -> Result<Option<(String, Type)>, String>;
}

impl SynFnArgHelpers for syn::FnArg {
    fn as_ident_and_type(&self) -> Result<Option<(String, Type)>, String> {
        match self {
            &syn::FnArg::Captured(syn::Pat::Ident(_, ref ident, _), ref ty) => {
                if let Some(x) = Type::load(ty)? {
                    Ok(Some((ident.to_string(), x)))
                } else {
                    Ok(None)
                }
            }
            _ => Err(format!("parameter has unexpected type")),
        }
    }
}