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// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
// This is a test which attempts to blow out the system limit with how many
// arguments can be passed to a process. This'll successively call rustc with
// larger and larger argument lists in an attempt to find one that's way too
// big for the system at hand. This file itself is then used as a "linker" to
// detect when the process creation succeeds.
//
// Eventually we should see an argument that looks like `@` as we switch from
// passing literal arguments to passing everything in the file.
use std::env;
use std::fs::{self, File};
use std::io::{BufWriter, Write, Read};
use std::path::PathBuf;
use std::process::Command;
fn main() {
let tmpdir = PathBuf::from(env::var_os("TMPDIR").unwrap());
let ok = tmpdir.join("ok");
if env::var("YOU_ARE_A_LINKER").is_ok() {
if let Some(file) = env::args_os().find(|a| a.to_string_lossy().contains("@")) {
let file = file.to_str().expect("non-utf8 file argument");
fs::copy(&file[1..], &ok).unwrap();
}
return
}
let rustc = env::var_os("RUSTC").unwrap_or("rustc".into());
let me_as_linker = format!("linker={}", env::current_exe().unwrap().display());
for i in (1..).map(|i| i * 100) {
println!("attempt: {}", i);
let file = tmpdir.join("bar.rs");
let mut f = BufWriter::new(File::create(&file).unwrap());
let mut lib_name = String::new();
for _ in 0..i {
lib_name.push_str("foo");
}
for j in 0..i {
writeln!(f, "#[link(name = \"{}{}\")]", lib_name, j).unwrap();
}
writeln!(f, "extern {{}}\nfn main() {{}}").unwrap();
f.into_inner().unwrap();
drop(fs::remove_file(&ok));
let output = Command::new(&rustc)
.arg(&file)
.arg("-C").arg(&me_as_linker)
.arg("--out-dir").arg(&tmpdir)
.env("YOU_ARE_A_LINKER", "1")
.output()
.unwrap();
if !output.status.success() {
let stderr = String::from_utf8_lossy(&output.stderr);
panic!("status: {}\nstdout:\n{}\nstderr:\n{}",
output.status,
String::from_utf8_lossy(&output.stdout),
stderr.lines().map(|l| {
if l.len() > 200 {
format!("{}...\n", &l[..200])
} else {
format!("{}\n", l)
}
}).collect::<String>());
}
if !ok.exists() {
continue
}
let mut contents = Vec::new();
File::open(&ok).unwrap().read_to_end(&mut contents).unwrap();
for j in 0..i {
let exp = format!("{}{}", lib_name, j);
let exp = if cfg!(target_env = "msvc") {
let mut out = Vec::with_capacity(exp.len() * 2);
for c in exp.encode_utf16() {
// encode in little endian
out.push(c as u8);
out.push((c >> 8) as u8);
}
out
} else {
exp.into_bytes()
};
assert!(contents.windows(exp.len()).any(|w| w == &exp[..]));
}
break
}
}
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