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
#![feature(quote, plugin_registrar, rustc_private, box_syntax, stmt_expr_attributes)]
extern crate rustc_plugin;
extern crate rustc_target;
extern crate syntax;
use rustc_plugin::registry::Registry;
use rustc_target::spec::abi::Abi;
use syntax::ast::{Attribute, Ident, Item, ItemKind, MetaItem, Mod, Name, Ty, VisibilityKind};
use syntax::attr;
use syntax::codemap::Span;
use syntax::ext::base::SyntaxExtension::{MultiModifier, NormalTT};
use syntax::ext::base::{Annotatable, ExtCtxt, MacEager, MacResult, MultiItemModifier,
TTMacroExpander};
use syntax::feature_gate::AttributeType;
use syntax::ptr::P;
use syntax::tokenstream::TokenStream;
use syntax::edition::Edition;
use std::cell::RefCell;
use std::rc::Rc;
use std::mem;
mod codegen;
mod util;
use util::{mod_walk, rustc::*, syntax::get_fn_info};
#[plugin_registrar]
pub fn plugin_registrar(reg: &mut Registry) {
let fn_list = Rc::new(RefCell::new(Vec::new()));
let header_extension = HotswapHeaderExtension {
fn_list: Rc::clone(&fn_list),
};
let macro_extension = HotswapMacroExtension {
fn_list: Rc::clone(&fn_list),
};
reg.register_syntax_extension(
Name::intern("hotswap_header"),
MultiModifier(box header_extension),
);
reg.register_syntax_extension(
Name::intern("hotswap_start"),
NormalTT {
expander: box macro_extension,
def_info: None,
allow_internal_unsafe: false,
allow_internal_unstable: false,
unstable_feature: None,
edition: Edition::Edition2015
},
);
reg.register_attribute("hotswap".to_string(), AttributeType::Whitelisted);
}
pub struct HotswapFnInfo {
name: String,
input_types: Vec<Ty>,
input_idents: Vec<Ident>,
output_type: P<Ty>,
}
type HotswapFnList = Vec<HotswapFnInfo>;
struct HotswapHeaderExtension {
fn_list: Rc<RefCell<HotswapFnList>>,
}
struct HotswapMacroExtension {
fn_list: Rc<RefCell<HotswapFnList>>,
}
impl MultiItemModifier for HotswapHeaderExtension {
fn expand(
&self,
cx: &mut ExtCtxt,
_: Span,
_: &MetaItem,
annotatable: Annotatable,
) -> Vec<Annotatable> {
if let Annotatable::Item(item) = annotatable {
let mut item = item.into_inner();
if let ItemKind::Mod(m) = item.node {
item.node = ItemKind::Mod(match crate_type().as_ref() {
"bin" => {
let mut hotswap_fns = self.fn_list.borrow_mut();
let tmp = expand_bin_mod(cx, m, &mut hotswap_fns);
expand_bin_footer(cx, tmp, &mut hotswap_fns)
}
"dylib" => expand_lib_mod(cx, m),
_ => unimplemented!(),
});
item.attrs = match crate_type().as_ref() {
"dylib" => expand_lib_attrs(cx, item.attrs),
_ => item.attrs,
};
return vec![Annotatable::Item(P(item))];
}
}
unimplemented!();
}
}
impl TTMacroExpander for HotswapMacroExtension {
fn expand(&self, cx: &mut ExtCtxt, _: Span, tt: TokenStream) -> Box<MacResult> {
let hotswap_fns = self.fn_list.borrow();
if hotswap_fns.is_empty() {
return MacEager::expr(quote_expr!(cx, {
&*(0 as *const usize);
}));
}
if !tt.is_empty() {
unimplemented!();
}
MacEager::expr(codegen::macro_expansion(cx, &hotswap_fns))
}
}
fn expand_lib_attrs(cx: &mut ExtCtxt, mut attrs: Vec<Attribute>) -> Vec<Attribute> {
attrs.insert(0, quote_attr!(cx, #![allow(unused_imports)]));
attrs.insert(0, quote_attr!(cx, #![allow(dead_code)]));
attrs.insert(0, quote_attr!(cx, #![allow(unused_features)]));
attrs
}
fn expand_lib_mod(cx: &mut ExtCtxt, m: Mod) -> Mod {
mod_walk(m, &mut |item| {
if attr::contains_name(&item.attrs, "hotswap") {
match item.node {
ItemKind::Fn(..) => return expand_lib_fn(cx, item),
_ => println!("warning: hotswap only works on functions"),
}
expand_lib_fn(cx, item)
} else {
item
}
})
}
fn expand_lib_fn(cx: &mut ExtCtxt, mut item: Item) -> Item {
if let ItemKind::Fn(_, ref mut header, _, _) = item.node {
item.attrs.push(quote_attr!(cx, #![no_mangle]));
item.vis.node = VisibilityKind::Public;
mem::replace(&mut header.abi, Abi::Rust);
}
item
}
fn expand_bin_mod(cx: &mut ExtCtxt, m: Mod, hotswap_fns: &mut HotswapFnList) -> Mod {
mod_walk(m, &mut |item: Item| {
if attr::contains_name(&item.attrs, "hotswap") {
match item.node {
ItemKind::Fn(..) => return expand_bin_fn(cx, item, hotswap_fns),
_ => println!("warning: hotswap only works on functions"),
}
}
item
})
}
fn expand_bin_fn(cx: &mut ExtCtxt, mut item: Item, hotswap_fns: &mut HotswapFnList) -> Item {
let fn_info = get_fn_info(cx, &item);
if let ItemKind::Fn(_, _, _, ref mut block) = item.node {
mem::replace(block, codegen::fn_body(cx, &fn_info));
}
hotswap_fns.push(fn_info);
item
}
fn expand_bin_footer(cx: &mut ExtCtxt, mut m: Mod, hotswap_fns: &mut HotswapFnList) -> Mod {
m.items
.insert(0, quote_item!(cx, extern crate hotswap_runtime;).unwrap());
m.items.push(codegen::runtime_mod(cx, hotswap_fns));
m
}