Hide unstable print kinds within emit_unknown_print_request_help in stable channel

[xizheyin]

Fixes #138698

We need to get the channel from matches. However, since matches(Line 1169) is constructed after rustc_optgroups (Line1165, where RustcOptGroup::value_hint is generated, i.e. what rustc --print print prints), I've left it unchanged here for now.

rust/compiler/rustc_driver_impl/src/lib.rs

Lines 1161 to 1169 in 2da29db

	pub fn handle_options(early_dcx: &EarlyDiagCtxt, args: &[String]) -> Option<getopts::Matches> {
	// Parse with *all* options defined in the compiler, we don't worry about
	// option stability here we just want to parse as much as possible.
	let mut options = getopts::Options::new();
	let optgroups = config::rustc_optgroups();
	for option in &optgroups {
	option.apply(&mut options);
	}
	let matches = options.parse(args).unwrap_or_else(|e| {

There is actually a way to manually parse the --crate-name parameter, but I'm afraid that's an unorthodox practice. So I conservatively just modified emit_unknown_print_request_help to print different parameters depending on whether they are nightly or not when passing the error parameter.

r? @jieyouxu

[rustbot]

r? @petrochenkov

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[jieyouxu]

Can you add a functional test for this change? In the test, I'd also like to see exercised:

• Single stable print flag vs single unstable print flag
• Mixed unstable/stable print flag

[xizheyin]

Sure no problem, but I would like to know how to add functional tests, is it done locally to me?

[jieyouxu]

As in, a ui test

e.g. https://rustc-dev-guide.rust-lang.org/tests/adding.html

[xizheyin]

Ooh, I have no idea to control the channel, e.g. nightly or stable, in the ui test. It may be like

//@ compile-flags: --print zzz
//@ exec-env:CFG_CHANNEL=stable

//~? ERROR unknown print request: `zzz`

or

//@ exec-env:CFG_RELEASE_CHANNEL=stable

or

//@ exec-env:CFG_DISABLE_UNSTABLE_FEATURES=1

But they are failed. Do you have any suggestion?

[jieyouxu]

What you can do for the purpose of this test (RUSTC_BOOTSTRAP=1 will permit unstable features, which as a corollary should cause the nightly gating you have to be active)

//@ revisions: force_stable force_unstable
//@[force_stable] rustc-env: RUSTC_BOOTSTRAP=-1
//@[force_unstable] rustc-env: RUSTC_BOOTSTRAP=1

[xizheyin]

It works, but it passes unstable flags -Z to the rustc,

command: env -u RUSTC_LOG_COLOR RUSTC_BOOTSTRAP="-1" RUSTC_ICE="0" RUST_BACKTRACE="short" "/home/nju/rust/build/x86_64-unknown-linux-gnu/stage1/bin/rustc" "/home/nju/rust/tests/ui/print-request/hide-unstable-in-stable-issue-138698.rs" "-Zthreads=1" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Z" "ignore-directory-in-diagnostics-source-blocks=/home/nju/.cargo" "-Z" "ignore-directory-in-diagnostics-source-blocks=/home/nju/rust/vendor" "--sysroot" "/home/nju/rust/build/x86_64-unknown-linux-gnu/stage1" "--target=x86_64-unknown-linux-gnu" "--cfg" "force_stable" "--check-cfg" "cfg(test,FALSE,force_stable,force_unstable)" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/home/nju/rust/build/x86_64-unknown-linux-gnu/test/ui/print-request/hide-unstable-in-stable-issue-138698.force_stable" "-A" "unused" "-A" "internal_features" "-Crpath" "-Cdebuginfo=0" "-Lnative=/home/nju/rust/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "--print" "xxx"

and report

error: the option `Z` is only accepted on the nightly compiler

help: consider switching to a nightly toolchain: `rustup default nightly`

note: selecting a toolchain with `+toolchain` arguments require a rustup proxy; see <https://rust-lang.github.io/rustup/concepts/index.html>

note: for more information about Rust's stability policy, see <https://doc.rust-lang.org/book/appendix-07-nightly-rust.html#unstable-features>

error: 1 nightly option were parsed

How to turn off the flags?

By the way, would it be better to write it to rustc_develop_guide, I didn't find this in the documentation.

[jieyouxu]

Oh right I forgor about the ui test preset flags. In this case, can you use a run-make test instead, since you want to explicitly control and constrain the exact compiler flags you want to pass.

[jieyouxu]

By the way, would it be better to write it to rustc_develop_guide, I didn't find this in the documentation.

https://rustc-dev-guide.rust-lang.org/tests/misc.html

[rustbot]

This PR modifies run-make tests.

cc @jieyouxu

[xizheyin]

I've added a run-make test for current PR, and a few more that may help later with changes to the relevant topic. So I named it print-in-stable-or-unstable-channel.

[jieyouxu]

Thanks, some more nits

[jieyouxu]

I've added a run-make test for current PR, and a few more that may help later with changes to the relevant topic. So I named it print-in-stable-or-unstable-channel.

Can you call it sth like "print-request-help-stable-unstable" instead (see the review comments above regarding redundant tests)?

[xizheyin]

Thank you, I revised it. : ) @jieyouxu

[jieyouxu]

Looks good for the most part, some suggestions

[xizheyin]

I updated it. 😊

[jieyouxu]

BTW you can mark PR as ready for review with @rustbot review, otherwise I might not look at S-waiting-on-author PRs in my review queue.

[jieyouxu]

Thanks, can you squash the commits into one?

[xizheyin]

Ok, so that's how you review.

@rustbot review

[jieyouxu]

Ah yeah, triagebot would print that help message about @rustbot ready (review is an alias for ready) now if I explicitly write:

@rustbot author

[rustbot]

Reminder, once the PR becomes ready for a review, use @rustbot ready.

[jieyouxu]

Thanks

[jieyouxu]

@bors r+ rollup

[bors]

📌 Commit 8562110 has been approved by jieyouxu

It is now in the queue for this repository.