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
|
// SPDX-License-Identifier: GPL-2.0
//! The custom target specification file generator for `rustc`.
//!
//! To configure a target from scratch, a JSON-encoded file has to be passed
//! to `rustc` (introduced in [RFC 131]). These options and the file itself are
//! unstable. Eventually, `rustc` should provide a way to do this in a stable
//! manner. For instance, via command-line arguments. Therefore, this file
//! should avoid using keys which can be set via `-C` or `-Z` options.
//!
//! [RFC 131]: https://rust-lang.github.io/rfcs/0131-target-specification.html
use std::{
collections::HashMap,
fmt::{Display, Formatter, Result},
io::BufRead,
};
enum Value {
Boolean(bool),
Number(i32),
String(String),
Object(Object),
}
type Object = Vec<(String, Value)>;
/// Minimal "almost JSON" generator (e.g. no `null`s, no arrays, no escaping),
/// enough for this purpose.
impl Display for Value {
fn fmt(&self, formatter: &mut Formatter<'_>) -> Result {
match self {
Value::Boolean(boolean) => write!(formatter, "{}", boolean),
Value::Number(number) => write!(formatter, "{}", number),
Value::String(string) => write!(formatter, "\"{}\"", string),
Value::Object(object) => {
formatter.write_str("{")?;
if let [ref rest @ .., ref last] = object[..] {
for (key, value) in rest {
write!(formatter, "\"{}\": {},", key, value)?;
}
write!(formatter, "\"{}\": {}", last.0, last.1)?;
}
formatter.write_str("}")
}
}
}
}
struct TargetSpec(Object);
impl TargetSpec {
fn new() -> TargetSpec {
TargetSpec(Vec::new())
}
}
trait Push<T> {
fn push(&mut self, key: &str, value: T);
}
impl Push<bool> for TargetSpec {
fn push(&mut self, key: &str, value: bool) {
self.0.push((key.to_string(), Value::Boolean(value)));
}
}
impl Push<i32> for TargetSpec {
fn push(&mut self, key: &str, value: i32) {
self.0.push((key.to_string(), Value::Number(value)));
}
}
impl Push<String> for TargetSpec {
fn push(&mut self, key: &str, value: String) {
self.0.push((key.to_string(), Value::String(value)));
}
}
impl Push<&str> for TargetSpec {
fn push(&mut self, key: &str, value: &str) {
self.push(key, value.to_string());
}
}
impl Push<Object> for TargetSpec {
fn push(&mut self, key: &str, value: Object) {
self.0.push((key.to_string(), Value::Object(value)));
}
}
impl Display for TargetSpec {
fn fmt(&self, formatter: &mut Formatter<'_>) -> Result {
// We add some newlines for clarity.
formatter.write_str("{\n")?;
if let [ref rest @ .., ref last] = self.0[..] {
for (key, value) in rest {
write!(formatter, " \"{}\": {},\n", key, value)?;
}
write!(formatter, " \"{}\": {}\n", last.0, last.1)?;
}
formatter.write_str("}")
}
}
struct KernelConfig(HashMap<String, String>);
impl KernelConfig {
/// Parses `include/config/auto.conf` from `stdin`.
fn from_stdin() -> KernelConfig {
let mut result = HashMap::new();
let stdin = std::io::stdin();
let mut handle = stdin.lock();
let mut line = String::new();
loop {
line.clear();
if handle.read_line(&mut line).unwrap() == 0 {
break;
}
if line.starts_with('#') {
continue;
}
let (key, value) = line.split_once('=').expect("Missing `=` in line.");
result.insert(key.to_string(), value.trim_end_matches('\n').to_string());
}
KernelConfig(result)
}
/// Does the option exist in the configuration (any value)?
///
/// The argument must be passed without the `CONFIG_` prefix.
/// This avoids repetition and it also avoids `fixdep` making us
/// depend on it.
fn has(&self, option: &str) -> bool {
let option = "CONFIG_".to_owned() + option;
self.0.contains_key(&option)
}
}
fn main() {
let cfg = KernelConfig::from_stdin();
let mut ts = TargetSpec::new();
// `llvm-target`s are taken from `scripts/Makefile.clang`.
if cfg.has("ARM64") {
panic!("arm64 uses the builtin rustc aarch64-unknown-none target");
} else if cfg.has("X86_64") {
ts.push("arch", "x86_64");
ts.push(
"data-layout",
"e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128",
);
let mut features = "-3dnow,-3dnowa,-mmx,+soft-float".to_string();
if cfg.has("MITIGATION_RETPOLINE") {
features += ",+retpoline-external-thunk";
}
ts.push("features", features);
ts.push("llvm-target", "x86_64-linux-gnu");
ts.push("target-pointer-width", "64");
} else if cfg.has("LOONGARCH") {
ts.push("arch", "loongarch64");
ts.push("data-layout", "e-m:e-p:64:64-i64:64-i128:128-n64-S128");
ts.push("features", "-f,-d");
ts.push("llvm-target", "loongarch64-linux-gnusf");
ts.push("llvm-abiname", "lp64s");
ts.push("target-pointer-width", "64");
} else {
panic!("Unsupported architecture");
}
ts.push("emit-debug-gdb-scripts", false);
ts.push("frame-pointer", "may-omit");
ts.push(
"stack-probes",
vec![("kind".to_string(), Value::String("none".to_string()))],
);
// Everything else is LE, whether `CPU_LITTLE_ENDIAN` is declared or not
// (e.g. x86). It is also `rustc`'s default.
if cfg.has("CPU_BIG_ENDIAN") {
ts.push("target-endian", "big");
}
println!("{}", ts);
}
|
