Rethink supporting Windows XP

[liigo]

I've made some investigation recently, and found that, there are only two APIs which are not supported by Windows XP, throughout the repo tree. There are:

• CreateSymbolicLinkW, only used by native::io::file::symlink()
• GetFinalPathNameByHandleW, only used by native::io::file::readlink()

And native::io::file::{symlink,readlink} are never used throughout the repo tree, except std::io::fs::{symlink,readlink} (which are really never used).

Do we really need including symlink/readlink functionality inside std? How other languages do?

Currently Windows XP is still wildly used in the world, especially in Asia. Its installed volume is much more than Mac OS + Linux + Unix. We give up supporting XP just because of two api absent? Maybe it's wrong.

cc #11950

update: readlink is used by rustc::metadata::filesearch.

update: This is my branch: https://github.com/liigo/rust/tree/xp
I just commented out the usage of CreateSymbolicLinkW and GetFinalPathNameByHandleW. This make the new rustc.exe run successfully in Windows XP, ant it works mostly OK (see my latest comment below).

[huonw]

I thought there were mutex and condition variable APIs that are not supported on windows XP too?

[liigo]

@huonw After remove CreateSymbolicLinkW and GetFinalPathNameByHandleW, I've made rustc run in XP (it works ok). More investigation need to be done perhaps.

[huonw]

Oh, really? Does it pass tests?

(cc #11950 )

[liigo]

I don't know. On Windows platform (even Win7), make check always fails. see #12745

[huonw]

make check-fast or even just make check-stage2-std should pass (at least, they pass on the buildbots).

[liigo]

I'll have a try. Thank you! @huonw

In general, a .exe can't be start up, if it includes unsupported APIs in Import Table. Before i remove CreateSymbolicLinkW and GetFinalPathNameByHandleW from source, rustc can't be start up in XP; after removing, the new rustc runs normally. So I think, rustc doesn't require other unsupported API. Will prove it.

Update: my new rustc.exe can be loaded successfully by depends.exe in XP. Yes, It has no other dependency.

[liigo]

@huonw
make check-fast:

run-pass [stage2]: test\run-pass\exponential-notation.rs
task '<main>' failed at 'called `Option::unwrap()` on a `None` value', D:\MinGW\msys\1.0\home\LIIGO\rust\rust\src\libstd
\option.rs:148
make: *** [i686-pc-mingw32/test/run_pass_stage2_driver-i686-pc-mingw32.out] Error 101

(This is not my fault, IMO)

make check-stage2-std: All tests passed. (update: Runs in Win7, sorry!)

This is my branch: https://github.com/liigo/rust/tree/xp
I just commented out the usage of CreateSymbolicLinkW and GetFinalPathNameByHandleW.

[bharrisau]

Might be an issue with UTF8 or floating point arithmetic on XP?
https://github.com/mozilla/rust/blob/master/src/libstd/num/strconv.rs#471

[liigo]

@bharrisau Are you sure?

I've compiled the std and its tests from source in Windows XP using my new rustc.exe. Compiled OK, most tests passed, and some tests failed (1276 passed; 41 failed; 134 ignored):

(Looks like all failures are from libgreen and libnative. But I don't know why currently.)

failures:

---- io::net::tcp::test::multiple_connect_serial_ip6::green stdout ----
    task 'io::net::tcp::test::multiple_connect_serial_ip6::green' failed at 'called `Result::unwrap()` on an `Err` value', src\libstd\result.rs:187

---- io::net::tcp::test::multiple_connect_serial_ip6::native stdout ----
    task 'io::net::tcp::test::multiple_connect_serial_ip6::native' failed at 'receiving on a closed channel', src\libstd\comm\mod.rs:507

---- io::net::tcp::test::read_eof_twice_ip6::green stdout ----
    task 'io::net::tcp::test::read_eof_twice_ip6::green' failed at 'unknown kind: OtherIoError', src\libstd\io\net\tcp.rs:294

---- io::net::tcp::test::read_eof_twice_ip6::native stdout ----
    task 'io::net::tcp::test::read_eof_twice_ip6::native' failed at 'receiving on a closed channel', src\libstd\comm\mod.rs:507

---- io::net::tcp::test::smoke_test_ip6::green stdout ----
    task 'io::net::tcp::test::smoke_test_ip6::green' failed at 'called `Result::unwrap()` on an `Err` value', src\libstd\result.rs:187

---- io::net::tcp::test::smoke_test_ip6::native stdout ----
    task 'io::net::tcp::test::smoke_test_ip6::native' failed at 'receiving on a closed channel', src\libstd\comm\mod.rs:507

---- io::net::tcp::test::socket_and_peer_name_ip6::green stdout ----
    task 'io::net::tcp::test::socket_and_peer_name_ip6::green' failed at 'called `Result::unwrap()` on an `Err` value', src\libstd\result.rs:187

---- io::net::tcp::test::socket_and_peer_name_ip6::native stdout ----
    task 'io::net::tcp::test::socket_and_peer_name_ip6::native' failed at 'receiving on a closed channel', src\libstd\comm\mod.rs:507

---- io::net::tcp::test::tcp_clone_two_read::green stdout ----
    task 'io::net::tcp::test::tcp_clone_two_read::green' failed at 'called `Result::unwrap()` on an `Err` value', src\libstd\result.rs:187

---- io::net::tcp::test::tcp_clone_two_read::native stdout ----
    task 'io::net::tcp::test::tcp_clone_two_read::native' failed at 'receiving on a closed channel', src\libstd\comm\mod.rs:507

---- io::net::tcp::test::write_close_ip6::green stdout ----
    task 'io::net::tcp::test::write_close_ip6::green' failed at 'unknown error: io::IoError{kind: OtherIoError, desc: "address family not supported", detail: None}', src\libstd\io\net\tcp.rs:348

---- io::net::tcp::test::write_close_ip6::native stdout ----
    task 'io::net::tcp::test::write_close_ip6::native' failed at 'receiving on a closed channel', src\libstd\comm\mod.rs:507

---- io::net::udp::test::socket_name_ip6::green stdout ----
    task 'io::net::udp::test::socket_name_ip6::green' failed at 'assertion failed: server.is_ok()', src\libstd\io\net\udp.rs:253

---- io::net::udp::test::socket_name_ip6::native stdout ----
    task 'io::net::udp::test::socket_name_ip6::native' failed at 'receiving on a closed channel', src\libstd\comm\mod.rs:507

---- io::net::udp::test::socket_smoke_test_ip6::green stdout ----
    task 'io::net::udp::test::socket_smoke_test_ip6::green' failed at 'explicit failure', src\libstd\io\net\udp.rs:142

---- io::net::udp::test::socket_smoke_test_ip6::native stdout ----
    task 'io::net::udp::test::socket_smoke_test_ip6::native' failed at 'receiving on a closed channel', src\libstd\comm\mod.rs:507

---- io::net::udp::test::stream_smoke_test_ip6::green stdout ----
    task 'io::net::udp::test::stream_smoke_test_ip6::green' failed at 'explicit failure', src\libstd\io\net\udp.rs:212

---- io::net::udp::test::stream_smoke_test_ip6::native stdout ----
    task 'io::net::udp::test::stream_smoke_test_ip6::native' failed at 'receiving on a closed channel', src\libstd\comm\mod.rs:507

---- io::process::tests::detach_works::green stdout ----
    task 'io::process::tests::detach_works::green' failed at 'called `Result::unwrap()` on an `Err` value', src\libstd\result.rs:187

---- io::process::tests::exit_reported_right::green stdout ----
    task 'io::process::tests::exit_reported_right::green' failed at 'assertion failed: p.is_ok()', src\libstd\io\process.rs:454

---- io::process::tests::detach_works::native stdout ----
    task 'io::process::tests::detach_works::native' failed at 'receiving on a closed channel', src\libstd\comm\mod.rs:507

---- io::process::tests::smoke::green stdout ----
    task 'io::process::tests::smoke::green' failed at 'assertion failed: p.is_ok()', src\libstd\io\process.rs:430

---- io::process::tests::exit_reported_right::native stdout ----
    task 'io::process::tests::exit_reported_right::native' failed at 'receiving on a closed channel', src\libstd\comm\mod.rs:507

---- io::process::tests::smoke::native stdout ----
    task 'io::process::tests::smoke::native' failed at 'receiving on a closed channel', src\libstd\comm\mod.rs:507

---- io::process::tests::stdout_works::green stdout ----
    task 'io::process::tests::stdout_works::green' failed at 'assertion failed: p.is_ok()', src\libstd\io\process.rs:487

---- io::process::tests::stdout_works::native stdout ----
    task 'io::process::tests::stdout_works::native' failed at 'receiving on a closed channel', src\libstd\comm\mod.rs:507

---- io::process::tests::test_finish_once::green stdout ----
    task 'io::process::tests::test_finish_once::green' failed at 'called `Result::unwrap()` on an `Err` value', src\libstd\result.rs:187

---- io::process::tests::test_finish_once::native stdout ----
    task 'io::process::tests::test_finish_once::native' failed at 'receiving on a closed channel', src\libstd\comm\mod.rs:507

---- io::process::tests::test_finish_twice::green stdout ----
    task 'io::process::tests::test_finish_twice::green' failed at 'called `Result::unwrap()` on an `Err` value', src\libstd\result.rs:187

---- io::process::tests::test_finish_twice::native stdout ----
    task 'io::process::tests::test_finish_twice::native' failed at 'receiving on a closed channel', src\libstd\comm\mod.rs:507

---- io::process::tests::test_process_output_error::green stdout ----
    task 'io::process::tests::test_process_output_error::green' failed at 'called `Result::unwrap()` on an `Err` value', src\libstd\result.rs:187

---- io::process::tests::test_process_output_error::native stdout ----
    task 'io::process::tests::test_process_output_error::native' failed at 'receiving on a closed channel', src\libstd\comm\mod.rs:507

---- io::process::tests::test_kill::native stdout ----
    task 'io::process::tests::test_kill::native' failed at 'receiving on a closed channel', src\libstd\comm\mod.rs:507

---- io::process::tests::test_process_output_output::green stdout ----
    task 'io::process::tests::test_process_output_output::green' failed at 'called `Result::unwrap()` on an `Err` value', src\libstd\result.rs:187

---- io::process::tests::test_process_output_output::native stdout ----
    task 'io::process::tests::test_process_output_output::native' failed at 'receiving on a closed channel', src\libstd\comm\mod.rs:507

---- io::process::tests::test_process_status::green stdout ----
    task 'io::process::tests::test_process_status::green' failed at 'called `Result::unwrap()` on an `Err` value', src\libstd\result.rs:187

---- io::process::tests::test_wait_with_output_once::green stdout ----
    task 'io::process::tests::test_wait_with_output_once::green' failed at 'called `Result::unwrap()` on an `Err` value', src\libstd\result.rs:187

---- io::process::tests::test_wait_with_output_once::native stdout ----
    task 'io::process::tests::test_wait_with_output_once::native' failed at 'receiving on a closed channel', src\libstd\comm\mod.rs:507

---- io::process::tests::test_wait_with_output_twice::green stdout ----
    task 'io::process::tests::test_wait_with_output_twice::green' failed at 'called `Result::unwrap()` on an `Err` value', src\libstd\result.rs:187

---- io::process::tests::test_process_status::native stdout ----
    task 'io::process::tests::test_process_status::native' failed at 'receiving on a closed channel', src\libstd\comm\mod.rs:507

---- io::process::tests::test_wait_with_output_twice::native stdout ----
    task 'io::process::tests::test_wait_with_output_twice::native' failed at 'receiving on a closed channel', src\libstd\comm\mod.rs:507

test result: FAILED. 1276 passed; 41 failed; 134 ignored; 0 measured

[bharrisau]

I just looked at that test you failed for uses of Option.unwrap. Was trying
to suggest why the test was failing even though you didn't change anything.

[liigo]

Thank you!
2014年3月12日 下午8:53于 "Ben Harris" notifications@github.com写道：

I just looked at that test you failed for uses of Option.unwrap. Was trying
to suggest why the test was failing even though you didn't change
anything.

—
Reply to this email directly or view it on GitHubhttps://github.com//issues/12842#issuecomment-37404548
.

[thestinger]

@huonw: Rust doesn't expose native condition variables yet. When it does, that's another API that's missing on XP. I don't think Rust should support an operating system not receiving security updates because encouraging any continued use of it is irresponsible. I don't think we should add a further burden to working on the concurrency and I/O implementation. It's already very hard to improve because libuv defines a lowest common denominator it needs to support, and XP would be another.

[liigo]

@thestinger I disagree with you. C, C++, Java, C#, Python, Ruby, Scala, and many more, all support Windows XP.