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Matthias Krüger 0643c3b910
Rollup merge of #128841 - lqd:rustc-args, r=onur-ozkan
bootstrap: don't use rustflags for `--rustc-args`

r? `@onur-ozkan`

This is going to require a bit of context.

https://github.com/rust-lang/rust/pull/47558 has added `--rustc-args` to `./x test` to allow passing flags when building `compiletest` tests. It was made specifically because using `RUSTFLAGS` would rebuild the compiler/stdlib, which would in turn require the flag you want to build tests with to successfully bootstrap.

#113178 made the request that it also works for other tests and doctests. This is not trivial to support across the board for `library`/`compiler` unit-tests/doctests and across stages. This issue was closed in #113948 by using `RUSTFLAGS`, seemingly incorrectly since https://github.com/rust-lang/rust/pull/123489 fixed that part to make it work.

Unfortunately #123489/#113948 have regressed the goals of `--rustc-args`:
- now we can't use rustc args that don't bootstrap, to run the UI tests: we can't test incomplete features. The new trait solver doesn't bootstrap, in-progress borrowck/polonius changes don't bootstrap, some other features are similarly incomplete, etc.
- using the flag now rebuilds everything from scratch: stage0 stdlib, stage1 compiler, stage1 stdlib. You don't need to re-do all this to compile UI tests, you only need the latter to run stdlib tests with a new flag, etc. This happens for contributors, but also on CI today. (Not to mention that in doing that it will rebuild things with flags that are not meant to be used, e.g. stdlib cfgs that don't exist in the compiler; or you could also imagine that this silently enables flags that were not meant to be enabled in this way).

Since then, https://github.com/rust-lang/rust/pull/125011/commits/bd71c71ea04b4a4f954e579c2a6d44113274846a has started using it to test a stdlib feature, relying on the fact that it now rebuilds everything. So #125011 also regressed CI times more than necessary because it rebuilds everything instead of just stage 1 stdlib.

It's not easy for me to know how to properly fix #113178 in bootstrap, but #113948/#123489 are not it since they regress the initial intent. I'd think bootstrap would have to know from the list of test targets that are passed that the `library` or `compiler` paths that are passed could require rebuilding these crates with different rustflags, probably also depending on stages. Therefore I would not be able to fix it, and will just try in this PR to unregress the situation to unblock the initial use-case.

It seems miri now also uses `./x miri --rustc-args` in this incorrect meaning to rebuild the `library` paths they support to run with the new args. I've not made any bootstrap changes related to `./x miri` in this PR, so `--rustc-args` wouldn't work there anymore. I'd assume this would need to use rustflags again but I don't know how to make that work properly in bootstrap, hence opening as draft, so you can tell me how to do that. I assume we don't want to break their use-case again now that it exists, even though there are ways to use `./x test` to do exactly that.

`RUSTFLAGS_NOT_BOOTSTRAP=flag ./x test library/std` is a way to run unit tests with a new flag without rebuilding everything, while with #123489 there is no way anymore to run tests with a flag that doesn't bootstrap.

---
edit: after review, this PR:
- renames `./x test --rustc-args` to `./x test --compiletest-rustc-args` as it only applies there, and cannot use rustflags for this purpose.
- fixes the regression that using these args rebuilt everything from scratch
- speeds up some CI jobs via the above point
- removes `./x miri --rustc-args` as only library tests are supported, needs to rebuild libstd, and `./x miri --compiletest-rustc-args` wouldn't work since compiletests are not supported.
2024-08-13 12:12:23 +02:00
.github Run abi-cafe tests for pull requests too 2024-08-07 09:35:31 +00:00
compiler Rollup merge of #128841 - lqd:rustc-args, r=onur-ozkan 2024-08-13 12:12:23 +02:00
library Rollup merge of #128745 - dtolnay:spawnunchecked, r=workingjubilee 2024-08-13 12:12:23 +02:00
LICENSES Include REUSE.toml in REUSE.toml. 2024-07-22 09:44:18 +01:00
src Rollup merge of #128841 - lqd:rustc-args, r=onur-ozkan 2024-08-13 12:12:23 +02:00
tests Rollup merge of #128643 - beetrees:ppc64-abi-fix, r=bjorn3 2024-08-13 12:12:21 +02:00
.clang-format Add .clang-format 2024-06-26 05:56:00 +08:00
.editorconfig Only use max_line_length = 100 for *.rs 2023-07-10 15:18:36 -07:00
.git-blame-ignore-revs Ignore use declaration reformatting in .git-blame-ignore-revs. 2024-08-01 14:33:17 +10:00
.gitattributes Rename config.toml.example to config.example.toml 2023-03-11 14:10:00 -08:00
.gitignore gitignore: Add Zed and Helix editors 2024-08-09 21:26:27 +01:00
.gitmodules Update to LLVM 19 2024-07-30 10:22:48 +02:00
.ignore Add .ignore file to make config.toml searchable in vscode 2024-06-24 10:15:16 +02:00
.mailmap trans her gender 2024-07-27 23:36:23 +00:00
Cargo.lock Add support for raw-dylib 2024-08-08 13:51:58 -07:00
Cargo.toml Add support for raw-dylib 2024-08-08 13:51:58 -07:00
CODE_OF_CONDUCT.md Remove the code of conduct; instead link https://www.rust-lang.org/conduct.html 2019-10-05 22:55:19 +02:00
config.example.toml Enable zstd for debug compression. 2024-08-09 05:55:23 -07:00
configure Ensure ./configure works when configure.py path contains spaces 2024-02-16 18:57:22 +00:00
CONTRIBUTING.md fix: Update CONTRIBUTING.md recommend -> recommended 2023-11-16 23:57:09 +05:30
COPYRIGHT Update COPYRIGHT file 2022-10-30 10:23:14 -04:00
INSTALL.md Rollup merge of #127434 - onur-ozkan:use-bootstrap-instead-of-rustbuild, r=Mark-Simulacrum 2024-07-13 20:19:45 -07:00
LICENSE-APACHE Remove appendix from LICENCE-APACHE 2019-12-30 14:25:53 +00:00
LICENSE-MIT LICENSE-MIT: Remove inaccurate (misattributed) copyright notice 2017-07-26 16:51:58 -07:00
README.md Use SVG logos in the README.md. 2024-04-03 19:48:20 +02:00
RELEASES.md Fix 1.80.0 version in RELEASES.md 2024-07-25 16:57:57 +02:00
REUSE.toml REUSE.toml: Copyright text isn't parsed as Markdown. 2024-08-06 11:04:55 +01:00
rust-bors.toml Increase timeout for new bors bot 2024-03-13 08:31:07 +01:00
rustfmt.toml Auto merge of #128083 - Mark-Simulacrum:bump-bootstrap, r=albertlarsan68 2024-07-30 17:49:08 +00:00
triagebot.toml Add a triagebot mention for library/Cargo.lock 2024-08-05 12:39:35 -05:00
x Make x capable of resolving symlinks 2023-10-14 17:53:33 +03:00
x.ps1 use & instead of start-process in x.ps1 2023-12-09 09:46:16 -05:00
x.py Fix recent python linting errors 2023-08-02 04:40:28 -04:00

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