Remove obsolete no_stack_check attribute and test

[infinity0]

Here is the start of the failure

failures:

---- [debuginfo-gdb] debuginfo-gdb/function-prologue-stepping-no-stack-check.rs stdout ----


executing armv7-unknown-linux-gnueabihf/stage2/bin/rustc /home/infinity0/rust/src/test/debuginfo/function-prologue-stepping-no-stack-check.rs -L armv7-unknown-linux-gnueabihf/test/debuginfo-gdb/ --target=armv7-unknown-linux-gnueabihf -L armv7-unknown-linux-gnueabihf/test/debuginfo-gdb/function-prologue-stepping-no-stack-check.stage2-armv7-unknown-linux-gnueabihf.debuginfo-gdb.libaux -C prefer-dynamic -o armv7-unknown-linux-gnueabihf/test/debuginfo-gdb/function-prologue-stepping-no-stack-check.stage2-armv7-unknown-linux-gnueabihf -C link-args=-Wl,-z,relro --cfg rtopt -C rpath -L armv7-unknown-linux-gnueabihf/rt -g
------stdout------------------------------

------stderr------------------------------
/home/infinity0/rust/src/test/debuginfo/function-prologue-stepping-no-stack-check.rs:253:1: 253:18 warning: unused attribute, #[warn(unused_attributes)] on by default
/home/infinity0/rust/src/test/debuginfo/function-prologue-stepping-no-stack-check.rs:253 #[no_stack_check]
                                                                                         ^~~~~~~~~~~~~~~~~
/home/infinity0/rust/src/test/debuginfo/function-prologue-stepping-no-stack-check.rs:270:1: 270:18 warning: unused attribute, #[warn(unused_attributes)] on by default
/home/infinity0/rust/src/test/debuginfo/function-prologue-stepping-no-stack-check.rs:270 #[no_stack_check]
                                                                                         ^~~~~~~~~~~~~~~~~
[..] many of these, basically one for every instance of no_stack_check in the file

After this basically everything is broken which you can see in more detail here. However, I see that no_stack_check isn't used in the code anywhere any more - there is only one grep result for stack[-_]check that excludes this test itself, and one of them says this:

src/libsyntax/feature_gate.rs-    // Not used any more, but we can't feature gate it
src/libsyntax/feature_gate.rs:    ("no_stack_check", Normal, Ungated),

So I wonder if this test should just be gotten rid of?

[nagisa]

The test probably should go.

[nagisa]

I think its also a time to deprecate the attribute by now. cc @rust-lang/compiler @rust-lang/lang

[michaelwoerister]

If the attribute doesn't have any effect anymore, the test case should be removed (while making sure that's it's still possible to break on a function, which might mean that we have to write another test case if that isn't covered anywhere else).

[infinity0]

fwiw, this test does pass on x86, x86-64 and even arm64

[pnkfelix]

It seems odd that the test is failing in this context, but not in the other targets that @infinity0 mentioned.

Nonetheless, the compiler team concluded we should:

1. kill this test,
2. kill this attribute,
3. kill any compiler flag that exposing a similar thingie.

[nikomatsakis]

I'll happily mentor someone to do this.

[abhijeetbhagat]

I can work on this.

[abhijeetbhagat]

So this is as simple as just deleting /src/test/debuginfo/function-prologue-stepping-regular.rs and removing this:
// Not used any more, but we can't feature gate it
("no_stack_check", Normal, Ungated),
from /src/libsyntax/feature_gate.rs ?

[nagisa]

You’ll also need to remove this flag. Getting the things you mentioned along with this flag deleted sounds correct.

[abhijeetbhagat]

I created three different pull requests because i did not know how to create a single pull request for multiple files. How can i do this in the future?

[nagisa]

I created three different pull requests because i did not know how to create a single pull request for multiple files. How can i do this in the future?

Did you perhaps make the PRs using github’s edit file feature? I do not think that feature was ever meant for anything more than quickly changing a typo in a single file.

The proper workflow (which allows for multi-file patches as well) is to:

• Fetch the project to your device;
• Change the files (as many of them as you want);
• Commit the changes to your local repository using any of the git tools available for your platform. Github has its own GUI application for Windows and Mac as well;
• Push your commit(s) to your github fork;
• Create a PR for your commit(s).

There a number of tutorials on how to get started with this workflow on the internet. In no particular order: 1, 2, 2.5, 3, 4, 5.

[pmatos]

What's still missing here?

[lambda-fairy]

@pmatos AFAIK, the only thing left to do is have -C no-stack-check print a deprecation warning when used. There was a pull request for this at #35156, but it was closed due to inactivity.

[mgattozzi]

This issue should be closed now right? It mentions in the release notes of #38966 that this has been fixed and it seems like #34915 was the one that closed the issue.

[michaelwoerister]

@mgattozzi Yes, looks like it. Thanks for the reminder!

[nagisa]

No. We still need to remove the flag. Please reopen.

[michaelwoerister]

Oh, I thought the issue was just about the test, sorry.

[danobi]

This issue was fixed in PR #37636. I believe this should be closed.

[nikomatsakis]

per @danobi's comment, closing