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merged 1 commit into from
Mar 9, 2023
Merged

Set LIBC_CHECK_CFG=1 when building Rust code in bootstrap #108898

merged 1 commit into from
Mar 9, 2023

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pietroalbini
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Downstream forks of the Rust compiler might want to use a custom libc to add support for targets that are not yet available upstream. Adding a patch to replace libc with a custom one would cause compilation errors though, because Cargo would interpret the custom libc as part of the workspace, and apply the check-cfg lints on it.

Since rust-lang/libc#3037, the libc build script emits check-cfg flags only when the LIBC_CHECK_CFG environment variable is set, so this PR allows the use of custom libcs.

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rustbot commented Mar 8, 2023

r? @Mark-Simulacrum

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@rustbot rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. T-bootstrap Relevant to the bootstrap subteam: Rust's build system (x.py and src/bootstrap) labels Mar 8, 2023
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Adding a patch to replace libc with a custom one would cause compilation errors though, because Cargo would interpret the custom libc as part of the workspace, and apply the check-cfg lints on it.

This is interesting to me - maybe a missing feature in Cargo? It seems common that you may want to patch a dependency (e.g., to switch to an as-yet unreleased version) without putting it into the workspace. Might be worth a bug report upstream.

@bors r+ for this in the meantime though.

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bors commented Mar 8, 2023

📌 Commit ead8b96 has been approved by Mark-Simulacrum

It is now in the queue for this repository.

@bors bors added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Mar 8, 2023
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This is interesting to me - maybe a missing feature in Cargo? It seems common that you may want to patch a dependency (e.g., to switch to an as-yet unreleased version) without putting it into the workspace. Might be worth a bug report upstream.

Whoops, "part of the workspace" was the wrong way to say it. The problem is that it's not recognized as an external dependency, so --cap-lints is not applied anymore.

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Sure, but I guess my point is that I think it should be possible to patch/vendor sources without treating things as internal. For example, building from a source tarball with vendored sources should work without needing this. So I think there's still a disconnect of some kind here.

@matthiaskrgr matthiaskrgr mentioned this pull request Mar 8, 2023
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I think it should be possible to patch/vendor sources without treating things as internal.

IIRC, overriding a dependency as git = 'my_path' instead of path = 'my_path' solves the issue.
(Maybe the path required file:// in the first case, but I don't remember exactly.)

bors added a commit to rust-lang-ci/rust that referenced this pull request Mar 9, 2023
@bors
Auto merge of rust-lang#108920 - matthiaskrgr:rollup-qrr9a0u, r=matth…
39f2657 
…iaskrgr

Rollup of 8 pull requests

Successful merges:

 - rust-lang#108754 (Retry `pred_known_to_hold_modulo_regions` with fulfillment if ambiguous)
 - rust-lang#108759 (1.41.1 supported 32-bit Apple targets)
 - rust-lang#108839 (Canonicalize root var when making response from new solver)
 - rust-lang#108856 (Remove DropAndReplace terminator)
 - rust-lang#108882 (Tweak E0740)
 - rust-lang#108898 (Set `LIBC_CHECK_CFG=1` when building Rust code in bootstrap)
 - rust-lang#108911 (Improve rustdoc-gui/tester.js code a bit)
 - rust-lang#108916 (Remove an unused return value in `rustc_hir_typeck`)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup
@bors bors merged commit 2ebb5b1 into rust-lang:master Mar 9, 2023
@rustbot rustbot added this to the 1.70.0 milestone Mar 9, 2023
@pietroalbini pietroalbini deleted the pa-libc-check-cfg branch March 9, 2023 15:20
flip1995 pushed a commit to flip1995/rust that referenced this pull request Mar 10, 2023
@bors
Auto merge of rust-lang#108920 - matthiaskrgr:rollup-qrr9a0u, r=matth…
eceedd9 
…iaskrgr

Rollup of 8 pull requests

Successful merges:

 - rust-lang#108754 (Retry `pred_known_to_hold_modulo_regions` with fulfillment if ambiguous)
 - rust-lang#108759 (1.41.1 supported 32-bit Apple targets)
 - rust-lang#108839 (Canonicalize root var when making response from new solver)
 - rust-lang#108856 (Remove DropAndReplace terminator)
 - rust-lang#108882 (Tweak E0740)
 - rust-lang#108898 (Set `LIBC_CHECK_CFG=1` when building Rust code in bootstrap)
 - rust-lang#108911 (Improve rustdoc-gui/tester.js code a bit)
 - rust-lang#108916 (Remove an unused return value in `rustc_hir_typeck`)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup
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