Restrict LLVM inline asm location cookie usage. Fixes #150451 by susitsm · Pull Request #160197 · rust-lang/rust

susitsm · 2026-07-30T06:46:24Z

The parallel frontend makes the cookies nondeterministic in their current form, resulting in nondeterministic outputs when bitcode is emitted or LTO is used.

Causes minor diagnostic regression for inline asm in release builds. See #150451 for details.

Fixes #150451

r? bjorn3

rustbot · 2026-07-30T07:21:16Z

rustc_codegen_gcc is developed in its own repository. If possible, consider making this change to rust-lang/rustc_codegen_gcc instead.

cc @antoyo, @GuillaumeGomez

rustc_codegen_cranelift is developed in its own repository. If possible, consider making this change to rust-lang/rustc_codegen_cranelift instead.

cc @bjorn3

petrochenkov · 2026-09-03T12:59:02Z

Is it possible to add a test case for this?
tests\run-make\parallel-reproducible-build\rmake.rs has some infra for it.
@rustbot author

rustbot · 2026-09-03T12:59:06Z

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

rustbot · 2026-09-03T14:46:32Z

This PR was rebased onto a different main commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.

petrochenkov · 2026-09-04T12:25:19Z

@bors try jobs=dist-armv7-linux

Restrict LLVM inline asm location cookie usage. Fixes #150451 try-job: dist-armv7-linux

rust-bors · 2026-09-04T14:09:41Z

☀️ Try build successful (CI)
Build commit: 8ae3936 (8ae3936981b03d57fde220a0672fb50e3c8169e7)
Base parent: b924f94 (b924f94129bce80f36dd9f08bb78dd5393fe196e)

…O is enabled The parallel frontend makes the cookies nondeterministic in their current form, resulting in nondeterministic outputs when bitcode is emitted or LTO is used. Causes minor diagnostic regression for inline asm in release builds.

susitsm · 2026-09-05T16:15:45Z

@rustbot ready

petrochenkov · 2026-09-07T12:42:38Z

@bors r+

rust-bors · 2026-09-07T12:42:41Z

📌 Commit 970cb98 has been approved by petrochenkov

It is now in the queue for this repository.

…s, r=petrochenkov Restrict LLVM inline asm location cookie usage. Fixes rust-lang#150451 The parallel frontend makes the cookies nondeterministic in their current form, resulting in nondeterministic outputs when bitcode is emitted or LTO is used. Causes minor diagnostic regression for inline asm in release builds. See rust-lang#150451 for details. Fixes rust-lang#150451 r? bjorn3

…uwer Rollup of 11 pull requests Successful merges: - #158153 (avoid spurious lifetime diagnostic in async generic case) - #160197 (Restrict LLVM inline asm location cookie usage. Fixes #150451) - #162413 (Unconditionally invalidate the library when the compiler changes) - #162294 (Reflection refactor ptrs) - #162354 (Make comptime functions ineligible for coverage) - #162379 (add test ensuring we refuse to const-eval the body of a rustc_do_not_const_check function) - #162386 (Add a regression test for trailing attributes in doctests) - #162410 (std: remove exceed whitespace in docs) - #162420 (mir_build: Don't pass a redundant `scrutinee_span` to some MIR-build methods) - #162430 (rustc-dev-guide subtree update) - #162431 (add next-solver FIXMEs)

Rollup merge of #160197 - susitsm:restrict-inline-asm-cookies, r=petrochenkov Restrict LLVM inline asm location cookie usage. Fixes #150451 The parallel frontend makes the cookies nondeterministic in their current form, resulting in nondeterministic outputs when bitcode is emitted or LTO is used. Causes minor diagnostic regression for inline asm in release builds. See #150451 for details. Fixes #150451 r? bjorn3

…ochenkov Restrict LLVM inline asm location cookie usage. Fixes #150451 The parallel frontend makes the cookies nondeterministic in their current form, resulting in nondeterministic outputs when bitcode is emitted or LTO is used. Causes minor diagnostic regression for inline asm in release builds. See #150451 for details. Fixes #150451 r? bjorn3

rustbot assigned bjorn3 Jul 30, 2026

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susitsm force-pushed the restrict-inline-asm-cookies branch 2 times, most recently from 1238b04 to e840de9 Compare July 30, 2026 06:49

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susitsm force-pushed the restrict-inline-asm-cookies branch from e840de9 to 4326f37 Compare July 30, 2026 07:21

susitsm mentioned this pull request Aug 10, 2026

parallel compiler: threads::spawnning loop not reproducible #150451

Closed

petrochenkov self-assigned this Aug 27, 2026

This was referenced Sep 1, 2026

rustc: Support --reproducible option for requesting reproducible output #160448

Open

Promoting Parallel Front End rust-lang/goals#121

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petrochenkov reviewed Sep 3, 2026

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Comment thread compiler/rustc_codegen_ssa/src/traits/backend.rs Outdated

rustbot added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Sep 3, 2026

susitsm force-pushed the restrict-inline-asm-cookies branch from 4326f37 to dbef79f Compare September 3, 2026 14:46

rustbot added the A-run-make Area: port run-make Makefiles to rmake.rs label Sep 3, 2026

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susitsm force-pushed the restrict-inline-asm-cookies branch 2 times, most recently from a22e364 to 6d6d87d Compare September 4, 2026 07:02

petrochenkov added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. and removed S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. labels Sep 4, 2026

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Comment thread tests/ui/asm/inline-syntax.rs

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rust-bors Bot pushed a commit that referenced this pull request Sep 4, 2026

Auto merge of #160197 - susitsm:restrict-inline-asm-cookies, r=<try>

8ae3936

Restrict LLVM inline asm location cookie usage. Fixes #150451 try-job: dist-armv7-linux

petrochenkov added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Sep 4, 2026

petrochenkov mentioned this pull request Sep 4, 2026

Non-deterministic builds with parallel-frontend-threads option #154259

Open

susitsm added 3 commits September 5, 2026 11:52

change compile-flags for asm ui tests to not embed bitcode or use LTO

0238ef9

add test for inline asm cookie reproducibility

fa5601d

susitsm force-pushed the restrict-inline-asm-cookies branch from 6d6d87d to 970cb98 Compare September 5, 2026 09:58

rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. and removed S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. labels Sep 5, 2026

rust-bors Bot 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 Sep 7, 2026

This was referenced Sep 7, 2026

Rollup of 8 pull requests #162427

Closed

Rollup of 11 pull requests #162434

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rust-bors Bot merged commit f04af20 into rust-lang:main Sep 7, 2026
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rustbot added this to the 1.100.0 milestone Sep 7, 2026

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susitsm commented Jul 30, 2026 •

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