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
214
215
216
217
218
219
220
221
222
223
224
|
use proc_macro2::{Ident, Span, TokenStream};
use quote::{quote, ToTokens};
use syn::{
parse::{Parse, ParseStream},
Data, DataStruct, DeriveInput, Field, Lit, Token,
};
use crate::util::{
create_metadata_items, derive_all_ffi_traits, either_attribute_arg, ident_to_string, kw,
mod_path, tagged_impl_header, try_metadata_value_from_usize, try_read_field, AttributeSliceExt,
UniffiAttributeArgs,
};
pub fn expand_record(input: DeriveInput, udl_mode: bool) -> syn::Result<TokenStream> {
let record = match input.data {
Data::Struct(s) => s,
_ => {
return Err(syn::Error::new(
Span::call_site(),
"This derive must only be used on structs",
));
}
};
let ident = &input.ident;
let ffi_converter = record_ffi_converter_impl(ident, &record, udl_mode)
.unwrap_or_else(syn::Error::into_compile_error);
let meta_static_var = (!udl_mode).then(|| {
record_meta_static_var(ident, &record).unwrap_or_else(syn::Error::into_compile_error)
});
Ok(quote! {
#ffi_converter
#meta_static_var
})
}
pub(crate) fn record_ffi_converter_impl(
ident: &Ident,
record: &DataStruct,
udl_mode: bool,
) -> syn::Result<TokenStream> {
let impl_spec = tagged_impl_header("FfiConverter", ident, udl_mode);
let derive_ffi_traits = derive_all_ffi_traits(ident, udl_mode);
let name = ident_to_string(ident);
let mod_path = mod_path()?;
let write_impl: TokenStream = record.fields.iter().map(write_field).collect();
let try_read_fields: TokenStream = record.fields.iter().map(try_read_field).collect();
Ok(quote! {
#[automatically_derived]
unsafe #impl_spec {
::uniffi::ffi_converter_rust_buffer_lift_and_lower!(crate::UniFfiTag);
fn write(obj: Self, buf: &mut ::std::vec::Vec<u8>) {
#write_impl
}
fn try_read(buf: &mut &[::std::primitive::u8]) -> ::uniffi::deps::anyhow::Result<Self> {
Ok(Self { #try_read_fields })
}
const TYPE_ID_META: ::uniffi::MetadataBuffer = ::uniffi::MetadataBuffer::from_code(::uniffi::metadata::codes::TYPE_RECORD)
.concat_str(#mod_path)
.concat_str(#name);
}
#derive_ffi_traits
})
}
fn write_field(f: &Field) -> TokenStream {
let ident = &f.ident;
let ty = &f.ty;
quote! {
<#ty as ::uniffi::Lower<crate::UniFfiTag>>::write(obj.#ident, buf);
}
}
pub enum FieldDefault {
Literal(Lit),
Null(kw::None),
}
impl ToTokens for FieldDefault {
fn to_tokens(&self, tokens: &mut TokenStream) {
match self {
FieldDefault::Literal(lit) => lit.to_tokens(tokens),
FieldDefault::Null(kw) => kw.to_tokens(tokens),
}
}
}
impl Parse for FieldDefault {
fn parse(input: ParseStream<'_>) -> syn::Result<Self> {
let lookahead = input.lookahead1();
if lookahead.peek(kw::None) {
let none_kw: kw::None = input.parse()?;
Ok(Self::Null(none_kw))
} else {
Ok(Self::Literal(input.parse()?))
}
}
}
#[derive(Default)]
pub struct FieldAttributeArguments {
pub(crate) default: Option<FieldDefault>,
}
impl UniffiAttributeArgs for FieldAttributeArguments {
fn parse_one(input: ParseStream<'_>) -> syn::Result<Self> {
let _: kw::default = input.parse()?;
let _: Token![=] = input.parse()?;
let default = input.parse()?;
Ok(Self {
default: Some(default),
})
}
fn merge(self, other: Self) -> syn::Result<Self> {
Ok(Self {
default: either_attribute_arg(self.default, other.default)?,
})
}
}
pub(crate) fn record_meta_static_var(
ident: &Ident,
record: &DataStruct,
) -> syn::Result<TokenStream> {
let name = ident_to_string(ident);
let module_path = mod_path()?;
let fields_len =
try_metadata_value_from_usize(record.fields.len(), "UniFFI limits structs to 256 fields")?;
let concat_fields: TokenStream = record
.fields
.iter()
.map(|f| {
let attrs = f
.attrs
.parse_uniffi_attr_args::<FieldAttributeArguments>()?;
let name = ident_to_string(f.ident.as_ref().unwrap());
let ty = &f.ty;
let default = match attrs.default {
Some(default) => {
let default_value = default_value_concat_calls(default)?;
quote! {
.concat_bool(true)
#default_value
}
}
None => quote! { .concat_bool(false) },
};
// Note: fields need to implement both `Lower` and `Lift` to be used in a record. The
// TYPE_ID_META should be the same for both traits.
Ok(quote! {
.concat_str(#name)
.concat(<#ty as ::uniffi::Lower<crate::UniFfiTag>>::TYPE_ID_META)
#default
})
})
.collect::<syn::Result<_>>()?;
Ok(create_metadata_items(
"record",
&name,
quote! {
::uniffi::MetadataBuffer::from_code(::uniffi::metadata::codes::RECORD)
.concat_str(#module_path)
.concat_str(#name)
.concat_value(#fields_len)
#concat_fields
},
None,
))
}
fn default_value_concat_calls(default: FieldDefault) -> syn::Result<TokenStream> {
match default {
FieldDefault::Literal(Lit::Int(i)) if !i.suffix().is_empty() => Err(
syn::Error::new_spanned(i, "integer literals with suffix not supported here"),
),
FieldDefault::Literal(Lit::Float(f)) if !f.suffix().is_empty() => Err(
syn::Error::new_spanned(f, "float literals with suffix not supported here"),
),
FieldDefault::Literal(Lit::Str(s)) => Ok(quote! {
.concat_value(::uniffi::metadata::codes::LIT_STR)
.concat_str(#s)
}),
FieldDefault::Literal(Lit::Int(i)) => {
let digits = i.base10_digits();
Ok(quote! {
.concat_value(::uniffi::metadata::codes::LIT_INT)
.concat_str(#digits)
})
}
FieldDefault::Literal(Lit::Float(f)) => {
let digits = f.base10_digits();
Ok(quote! {
.concat_value(::uniffi::metadata::codes::LIT_FLOAT)
.concat_str(#digits)
})
}
FieldDefault::Literal(Lit::Bool(b)) => Ok(quote! {
.concat_value(::uniffi::metadata::codes::LIT_BOOL)
.concat_bool(#b)
}),
FieldDefault::Literal(_) => Err(syn::Error::new_spanned(
default,
"this type of literal is not currently supported as a default",
)),
FieldDefault::Null(_) => Ok(quote! {
.concat_value(::uniffi::metadata::codes::LIT_NULL)
}),
}
}
|
