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
|
// rust-lang/rust#101913: when you run your program explicitly via `ld.so`,
// `std::env::current_exe` will return the path of *that* program, and not
// the Rust program itself.
use std::io::{BufRead, BufReader};
use std::path::{Path, PathBuf};
use std::process::Command;
mod common;
fn main() {
if std::env::var(VAR).is_err() {
// the parent waits for the child; then we then handle either printing
// "test result: ok", "test result: ignored", or panicking.
match parent() {
Ok(()) => {
println!("test result: ok");
}
Err(EarlyExit::IgnoreTest(_)) => {
println!("test result: ignored");
}
Err(EarlyExit::IoError(e)) => {
println!("{} parent encoutered IoError: {:?}", file!(), e);
panic!();
}
}
} else {
// println!("{} running child", file!());
child().unwrap();
}
}
const VAR: &str = "__THE_TEST_YOU_ARE_LUKE";
#[derive(Debug)]
enum EarlyExit {
IgnoreTest(String),
IoError(std::io::Error),
}
impl From<std::io::Error> for EarlyExit {
fn from(e: std::io::Error) -> Self {
EarlyExit::IoError(e)
}
}
fn parent() -> Result<(), EarlyExit> {
// If we cannot re-exec this test, there's no point in trying to do it.
if common::cannot_reexec_the_test() {
return Err(EarlyExit::IgnoreTest("(cannot reexec)".into()));
}
let me = std::env::current_exe().unwrap();
let ld_so = find_interpreter(&me)?;
// use interp to invoke current exe, yielding child test.
//
// (if you're curious what you might compare this against, you can try
// swapping in the below definition for `result`, which is the easy case of
// not using the ld.so interpreter directly that Rust handled fine even
// prior to resolution of rust-lang/rust#101913.)
//
// let result = Command::new(me).env(VAR, "1").output()?;
let result = Command::new(ld_so).env(VAR, "1").arg(&me).output().unwrap();
if result.status.success() {
return Ok(());
}
println!("stdout:\n{}", String::from_utf8_lossy(&result.stdout));
println!("stderr:\n{}", String::from_utf8_lossy(&result.stderr));
println!("code: {}", result.status);
panic!();
}
fn child() -> Result<(), EarlyExit> {
let bt = backtrace::Backtrace::new();
println!("{:?}", bt);
let mut found_my_name = false;
let my_filename = file!();
'frames: for frame in bt.frames() {
let symbols = frame.symbols();
if symbols.is_empty() {
continue;
}
for sym in symbols {
if let Some(filename) = sym.filename() {
if filename.ends_with(my_filename) {
// huzzah!
found_my_name = true;
break 'frames;
}
}
}
}
assert!(found_my_name);
Ok(())
}
// we use the `readelf` command to extract the path to the interpreter requested
// by our binary.
//
// if we cannot `readelf` for some reason, or if we fail to parse its output,
// then we will just give up on this test (and not treat it as a test failure).
fn find_interpreter(me: &Path) -> Result<PathBuf, EarlyExit> {
let result = Command::new("readelf")
.arg("-l")
.arg(me)
.output()
.map_err(|_err| EarlyExit::IgnoreTest("readelf invocation failed".into()))?;
if result.status.success() {
let r = BufReader::new(&result.stdout[..]);
for line in r.lines() {
let line = line?;
let line = line.trim();
let prefix = "[Requesting program interpreter: ";
// This could use `line.split_once` and `suffix.rsplit_once` once the MSRV passes 1.52
if let Some(idx) = line.find(prefix) {
let (_, suffix) = line.split_at(idx + prefix.len());
if let Some(idx) = suffix.rfind("]") {
let (found_path, _ignore_remainder) = suffix.split_at(idx);
return Ok(found_path.into());
}
}
}
Err(EarlyExit::IgnoreTest(
"could not find interpreter from readelf output".into(),
))
} else {
Err(EarlyExit::IgnoreTest("readelf returned non-success".into()))
}
}
|
