bondrewd-derive 0.3.18

Bit-Level field packing with proc_macros
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
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170

use crate::structs::common::{FieldDataType, FieldInfo, NumberSignage, StructInfo};
use proc_macro2::TokenStream;
use quote::{format_ident, quote};

pub fn create_into_bytes_field_quotes(info: &StructInfo) -> Result<TokenStream, syn::Error> {
    // all of the fields set functions that disallow numbers that are too large to fit into bit length.
    let mut set_fns_quote = quote! {};
    for field in info.fields.iter() {
        let q = make_set_field_quote(field)?;
        set_fns_quote = quote! {
            #set_fns_quote
            #q
        };
    }
    Ok(set_fns_quote)
}

fn make_set_field_quote(field: &FieldInfo) -> Result<TokenStream, syn::Error> {
    let field_name = field.ident.as_ref().clone();
    Ok(match field.ty {
        FieldDataType::Number(ref size, ref sign, ref type_ident) => {
            let mut full_quote = quote! {
                self.#field_name = value.clone();
                value
            };
            let bit_length = field.bit_size();
            if bit_length != size * 8 {
                match sign {
                    NumberSignage::Signed => {
                        let max: i128 = ((2_u128.pow(bit_length as u32) / 2_u128) - 1) as i128;
                        let min = -max - 1;
                        let max_lit = proc_macro2::Literal::i128_unsuffixed(max);
                        let min_lit = proc_macro2::Literal::i128_unsuffixed(min);
                        full_quote = quote! {
                            if value > #max_lit {
                                self.#field_name = #max_lit;
                                #max_lit
                            } else if value < #min_lit {
                                self.#field_name = #min_lit;
                                #min_lit
                            } else {
                                #full_quote
                            }
                        };
                    }
                    NumberSignage::Unsigned => {
                        let max: u128 = 2_u128.pow(bit_length as u32) - 1;
                        let max_lit = proc_macro2::Literal::u128_unsuffixed(max);
                        full_quote = quote! {
                            if value > #max_lit {
                                self.#field_name = #max_lit;
                                #max_lit
                            }else {
                                #full_quote
                            }
                        };
                    }
                }
            }
            let field_fn_name = format_ident!("set_{}", field_name);
            quote! {
                fn #field_fn_name(&mut self, value: #type_ident) -> #type_ident {
                    #full_quote
                }
            }
        }
        FieldDataType::Float(ref size, ref type_ident) => {
            let mut full_quote = quote! {
                self.#field_name = value;
                value
            };
            let bit_length = field.bit_size();
            if bit_length != *size * 8_usize {
                let max: f64 = if *size == 4_usize {
                    f32::MAX as f64
                } else if *size == 8_usize {
                    f64::MAX
                } else {
                    return Err(syn::Error::new(
                        field.ident.span(),
                        "unsupported floating point size",
                    ));
                };
                let min: f64 = if *size == 4_usize {
                    f32::MIN as f64
                } else if *size == 8_usize {
                    f64::MIN
                } else {
                    return Err(syn::Error::new(
                        field.ident.span(),
                        "unsupported floating point size",
                    ));
                };
                let max_lit = proc_macro2::Literal::f64_unsuffixed(max);
                let min_lit = proc_macro2::Literal::f64_unsuffixed(min);
                full_quote = quote! {
                    if value > #max_lit {
                        self.#field_name = #max_lit;
                        #max_lit
                    }else if value < #min_lit {
                        self.#field_name = #min_lit;
                        #min_lit
                    }else {
                        #full_quote
                    }
                };
            }
            let field_fn_name = format_ident!("set_{}", field_name);
            quote! {
                fn #field_fn_name(&mut self, value: #type_ident) -> #type_ident {
                    #full_quote
                }
            }
        }
        FieldDataType::Enum(_, _, ref type_ident) => {
            let field_fn_name = format_ident!("set_{}", field_name);
            quote! {
                fn #field_fn_name(&mut self, value: #type_ident) {
                    self.value;
                }
            }
        }
        FieldDataType::Struct(_, ref type_ident) => {
            let field_fn_name = format_ident!("{}_mut_ref", field_name);
            quote! {
                fn #field_fn_name(&mut self) -> &mut #type_ident {
                    &mut self.#field_name
                }
            }
        }
        FieldDataType::Char(ref size, ref type_ident) => {
            let mut full_quote = quote! {
                self.#field_name = value.clone();
                value
            };
            let bit_length = field.bit_size();
            if bit_length != size * 8 {
                let max: u32 = 2_u32.pow(bit_length as u32) - 1;
                full_quote = quote! {
                    if value as u32 > #max {
                        self.#field_name = #max;
                        #max
                    }else {
                        #full_quote
                    }
                };
            }
            let field_fn_name = format_ident!("set_{}", field_name);
            quote! {
                fn #field_fn_name(&mut self, value: #type_ident) -> #type_ident {
                    #full_quote
                }
            }
        }
        FieldDataType::ElementArray(_, _, _) => {
            quote! {}
        }
        FieldDataType::BlockArray(_, _, _) => {
            quote! {}
        }
        FieldDataType::Boolean => {
            let field_fn_name = format_ident!("set_{}", field_name);
            quote! {
                fn #field_fn_name(&mut self, value: bool) {
                    self.#field_name = value;
                }
            }
        }
    })
}