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
|
//! Handles dynamic library loading for proc macro
use std::{
fs::File,
io,
path::{Path, PathBuf},
};
use libloading::Library;
use memmap2::Mmap;
use object::Object;
use proc_macro_api::ProcMacroKind;
use crate::{proc_macro::bridge, rustc_server::TokenStream};
const NEW_REGISTRAR_SYMBOL: &str = "_rustc_proc_macro_decls_";
fn invalid_data_err(e: impl Into<Box<dyn std::error::Error + Send + Sync>>) -> io::Error {
io::Error::new(io::ErrorKind::InvalidData, e)
}
fn is_derive_registrar_symbol(symbol: &str) -> bool {
symbol.contains(NEW_REGISTRAR_SYMBOL)
}
fn find_registrar_symbol(file: &Path) -> io::Result<Option<String>> {
let file = File::open(file)?;
let buffer = unsafe { Mmap::map(&file)? };
Ok(object::File::parse(&buffer)
.map_err(invalid_data_err)?
.exports()
.map_err(invalid_data_err)?
.into_iter()
.map(|export| export.name())
.filter_map(|sym| String::from_utf8(sym.into()).ok())
.find(|sym| is_derive_registrar_symbol(sym))
.map(|sym| {
// From MacOS docs:
// https://developer.apple.com/library/archive/documentation/System/Conceptual/ManPages_iPhoneOS/man3/dlsym.3.html
// Unlike other dyld API's, the symbol name passed to dlsym() must NOT be
// prepended with an underscore.
if cfg!(target_os = "macos") && sym.starts_with('_') {
sym[1..].to_owned()
} else {
sym
}
}))
}
/// Loads dynamic library in platform dependent manner.
///
/// For unix, you have to use RTLD_DEEPBIND flag to escape problems described
/// [here](https://github.com/fedochet/rust-proc-macro-panic-inside-panic-expample)
/// and [here](https://github.com/rust-lang/rust/issues/60593).
///
/// Usage of RTLD_DEEPBIND
/// [here](https://github.com/fedochet/rust-proc-macro-panic-inside-panic-expample/issues/1)
///
/// It seems that on Windows that behaviour is default, so we do nothing in that case.
#[cfg(windows)]
fn load_library(file: &Path) -> Result<Library, libloading::Error> {
unsafe { Library::new(file) }
}
#[cfg(unix)]
fn load_library(file: &Path) -> Result<Library, libloading::Error> {
use libloading::os::unix::Library as UnixLibrary;
use std::os::raw::c_int;
const RTLD_NOW: c_int = 0x00002;
const RTLD_DEEPBIND: c_int = 0x00008;
unsafe { UnixLibrary::open(Some(file), RTLD_NOW | RTLD_DEEPBIND).map(|lib| lib.into()) }
}
struct ProcMacroLibraryLibloading {
// Hold the dylib to prevent it from unloading
_lib: Library,
exported_macros: Vec<bridge::client::ProcMacro>,
}
impl ProcMacroLibraryLibloading {
fn open(file: &Path) -> io::Result<Self> {
let symbol_name = find_registrar_symbol(file)?.ok_or_else(|| {
invalid_data_err(format!("Cannot find registrar symbol in file {}", file.display()))
})?;
let lib = load_library(file).map_err(invalid_data_err)?;
let exported_macros = {
let macros: libloading::Symbol<&&[bridge::client::ProcMacro]> =
unsafe { lib.get(symbol_name.as_bytes()) }.map_err(invalid_data_err)?;
macros.to_vec()
};
Ok(ProcMacroLibraryLibloading { _lib: lib, exported_macros })
}
}
pub struct Expander {
inner: ProcMacroLibraryLibloading,
}
impl Expander {
pub fn new(lib: &Path) -> io::Result<Expander> {
// Some libraries for dynamic loading require canonicalized path even when it is
// already absolute
let lib = lib.canonicalize()?;
let lib = ensure_file_with_lock_free_access(&lib)?;
let library = ProcMacroLibraryLibloading::open(&lib)?;
Ok(Expander { inner: library })
}
pub fn expand(
&self,
macro_name: &str,
macro_body: &tt::Subtree,
attributes: Option<&tt::Subtree>,
) -> Result<tt::Subtree, bridge::PanicMessage> {
let parsed_body = TokenStream::with_subtree(macro_body.clone());
let parsed_attributes = attributes
.map_or(crate::rustc_server::TokenStream::new(), |attr| {
TokenStream::with_subtree(attr.clone())
});
for proc_macro in &self.inner.exported_macros {
match proc_macro {
bridge::client::ProcMacro::CustomDerive { trait_name, client, .. }
if *trait_name == macro_name =>
{
let res = client.run(
&crate::proc_macro::bridge::server::SameThread,
crate::rustc_server::Rustc::default(),
parsed_body,
false,
);
return res.map(|it| it.into_subtree());
}
bridge::client::ProcMacro::Bang { name, client } if *name == macro_name => {
let res = client.run(
&crate::proc_macro::bridge::server::SameThread,
crate::rustc_server::Rustc::default(),
parsed_body,
false,
);
return res.map(|it| it.into_subtree());
}
bridge::client::ProcMacro::Attr { name, client } if *name == macro_name => {
let res = client.run(
&crate::proc_macro::bridge::server::SameThread,
crate::rustc_server::Rustc::default(),
parsed_attributes,
parsed_body,
false,
);
return res.map(|it| it.into_subtree());
}
_ => continue,
}
}
Err(bridge::PanicMessage::String("Nothing to expand".to_string()))
}
pub fn list_macros(&self) -> Vec<(String, ProcMacroKind)> {
self.inner
.exported_macros
.iter()
.map(|proc_macro| match proc_macro {
bridge::client::ProcMacro::CustomDerive { trait_name, .. } => {
(trait_name.to_string(), ProcMacroKind::CustomDerive)
}
bridge::client::ProcMacro::Bang { name, .. } => {
(name.to_string(), ProcMacroKind::FuncLike)
}
bridge::client::ProcMacro::Attr { name, .. } => {
(name.to_string(), ProcMacroKind::Attr)
}
})
.collect()
}
}
/// Copy the dylib to temp directory to prevent locking in Windows
#[cfg(windows)]
fn ensure_file_with_lock_free_access(path: &Path) -> io::Result<PathBuf> {
use std::{ffi::OsString, time::SystemTime};
let mut to = std::env::temp_dir();
let file_name = path.file_name().ok_or_else(|| {
io::Error::new(
io::ErrorKind::InvalidInput,
format!("File path is invalid: {}", path.display()),
)
})?;
// generate a time deps unique number
let t = SystemTime::now().duration_since(std::time::UNIX_EPOCH).expect("Time went backwards");
let mut unique_name = OsString::from(t.as_millis().to_string());
unique_name.push(file_name);
to.push(unique_name);
std::fs::copy(path, &to).unwrap();
Ok(to)
}
#[cfg(unix)]
fn ensure_file_with_lock_free_access(path: &Path) -> io::Result<PathBuf> {
Ok(path.to_path_buf())
}
|
