Skip to content

progressive linking #564

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 2 commits into from
Nov 18, 2020
Merged

progressive linking #564

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
959d606
Implement progressive linking
maxded Nov 17, 2020
cedba33
Address feedback
maxded Nov 18, 2020
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
93 changes: 36 additions & 57 deletions src/lib.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1774,66 +1774,25 @@ impl Build {
}

fn assemble(&self, lib_name: &str, dst: &Path, objs: &[Object]) -> Result<(), Error> {
// Delete the destination if it exists as the `ar` tool at least on Unix
// appends to it, which we don't want.
// Delete the destination if it exists as we want to
// create on the first iteration instead of appending.
let _ = fs::remove_file(&dst);

let objects: Vec<_> = objs.iter().map(|obj| obj.dst.clone()).collect();
let target = self.get_target()?;
if target.contains("msvc") {
let (mut cmd, program) = self.get_ar()?;
let mut out = OsString::from("-out:");
out.push(dst);
cmd.arg(out).arg("-nologo");
for flag in self.ar_flags.iter() {
cmd.arg(flag);
}

// Similar to https://github.com/rust-lang/rust/pull/47507
// and https://github.com/rust-lang/rust/pull/48548
let estimated_command_line_len = objects
.iter()
.chain(&self.objects)
.map(|a| a.as_os_str().len())
.sum::<usize>();
if estimated_command_line_len > 1024 * 6 {
let mut args = String::from("\u{FEFF}"); // BOM
for arg in objects.iter().chain(&self.objects) {
args.push('"');
for c in arg.to_str().unwrap().chars() {
if c == '"' {
args.push('\\')
}
args.push(c)
}
args.push('"');
args.push('\n');
}

let mut utf16le = Vec::new();
for code_unit in args.encode_utf16() {
utf16le.push(code_unit as u8);
utf16le.push((code_unit >> 8) as u8);
}

let mut args_file = OsString::from(dst);
args_file.push(".args");
fs::File::create(&args_file)
.unwrap()
.write_all(&utf16le)
.unwrap();
let objs: Vec<_> = objs
.iter()
.map(|o| o.dst.clone())
.chain(self.objects.clone())
.collect();

let mut args_file_arg = OsString::from("@");
args_file_arg.push(args_file);
cmd.arg(args_file_arg);
} else {
cmd.args(&objects).args(&self.objects);
}
run(&mut cmd, &program)?;
for chunk in objs.chunks(100) {
self.assemble_progressive(dst, chunk)?;
}

if target.contains("msvc") {
// The Rust compiler will look for libfoo.a and foo.lib, but the
// MSVC linker will also be passed foo.lib, so be sure that both
// exist for now.

let lib_dst = dst.with_file_name(format!("{}.lib", lib_name));
let _ = fs::remove_file(&lib_dst);
match fs::hard_link(&dst, &lib_dst).or_else(|_| {
Expand All @@ -1848,6 +1807,29 @@ impl Build {
));
}
};
}

Ok(())
}

fn assemble_progressive(&self, dst: &Path, objs: &[PathBuf]) -> Result<(), Error> {
let target = self.get_target()?;

if target.contains("msvc") {
let (mut cmd, program) = self.get_ar()?;
let mut out = OsString::from("-out:");
out.push(dst);
cmd.arg(out).arg("-nologo");
for flag in self.ar_flags.iter() {
cmd.arg(flag);
}
// If the library file already exists, add the libary name
// as an argument to let lib.exe know we are appending the objs.
if dst.exists() {
cmd.arg(dst);
}
cmd.args(objs);
run(&mut cmd, &program)?;
} else {
let (mut ar, cmd) = self.get_ar()?;

Expand Down Expand Up @@ -1877,10 +1859,7 @@ impl Build {
for flag in self.ar_flags.iter() {
ar.arg(flag);
}
run(
ar.arg("crs").arg(dst).args(&objects).args(&self.objects),
&cmd,
)?;
run(ar.arg("crs").arg(dst).args(objs), &cmd)?;
}

Ok(())
Expand Down