Include startup crt objects on WASI for more outputs by alexcrichton · Pull Request #161421 · rust-lang/rust

alexcrichton · 2026-08-20T18:31:19Z

This commit adds the crt1-reactor.o object file in the list of pre-link-crt-objects for the {Dynamic,Static}Dylib output kinds for WASI targets. These previously were omitted I believe by accident and this means that the conventional _initialize function is not present which runs constructor functions, for example. This is additionally needed for the upcoming wasip3 target where this startup object file is more load bearing than it was previously and will become required.

rustbot · 2026-08-20T18:31:23Z

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rustbot · 2026-08-20T19:28:48Z

The run-make-support library was changed

cc @jieyouxu

bjorn3 · 2026-08-21T06:46:07Z

@@ -127,6 +127,8 @@ pub(super) fn pre_wasi_self_contained() -> CrtObjects {
        (LinkOutputKind::StaticNoPicExe, &["crt1-command.o"]),
        (LinkOutputKind::StaticPicExe, &["crt1-command.o"]),
        (LinkOutputKind::WasiReactorExe, &["crt1-reactor.o"]),


Do we still need the separate flag to enable usage of crt1-reactor.o?

View changes since the review

I don't recall the history here myself, but I suspect not, no.

cc #108097 That PR also changed from --no-entry to --entry _initialize, though not just on wasi, but all wasm targets.

I'd like to only handle WASI targets here, not all targets. That PR also never landed I believe? The goal of this change is to handle ABI details for the upcoming wasip3 target which is broken without linking these files.

I'd like to only handle WASI targets here, not all targets.

I'm aware.

That PR also never landed I believe?

Indeed. I was looking at why it never landed. I think because it was also touching other targets.

Wouldn't this PR also need to copy the --no-entry -> --entry _initialize change from that PR, but just for wasi? And maybe copy the table doc table change.

Sure, I've updated the table. I don't believe the --no-entry change is necessary -- with this PR _initialize is still exported works as intended.

rustbot · 2026-08-25T16:31:17Z

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.

fee1-dead · 2026-08-26T00:41:19Z

Sorry, not familiar enough to review :)

@rustbot reroll

folkertdev · 2026-08-26T09:08:26Z

r? @bjorn3

This commit adds the `crt1-reactor.o` object file in the list of pre-link-crt-objects for the `{Dynamic,Static}Dylib` output kinds for WASI targets. These previously were omitted I believe by accident and this means that the conventional `_initialize` function is not present which runs constructor functions, for example. This is additionally needed for the upcoming wasip3 target where this startup object file is more load bearing than it was previously and will become required.

bjorn3 · 2026-08-27T16:01:20Z

@bors r+

rust-bors · 2026-08-27T16:01:23Z

📌 Commit f9ad9e1 has been approved by bjorn3

It is now in the queue for this repository.

…, r=bjorn3 Include startup crt objects on WASI for more outputs This commit adds the `crt1-reactor.o` object file in the list of pre-link-crt-objects for the `{Dynamic,Static}Dylib` output kinds for WASI targets. These previously were omitted I believe by accident and this means that the conventional `_initialize` function is not present which runs constructor functions, for example. This is additionally needed for the upcoming wasip3 target where this startup object file is more load bearing than it was previously and will become required.

Rollup of 14 pull requests Successful merges: - #150075 (Implement clamp_to) - #159103 (fix(reborrow): recursive implementation) - #160848 (std: avoid aliasing violations when wrapping opaque C types) - #161421 (Include startup crt objects on WASI for more outputs) - #161805 (Prefer ambiguous candidates when deduplicating traits in scope, so `ambiguous_glob_imported_traits` doesn't depend on import order) - #161862 (Put data segment in specified section with link_section on wasm) - #161866 (delegation: add tests fixating behavior of delegating to default trait implementations) - #161456 (reduce perf impact of scalar size checks) - #161666 (Print vendor instructions in `x vendor`) - #161730 (Improve type mismatch annotation for lets with block-wrapped initializers) - #161828 (Never type after-stabilization cleanup) - #161860 (atomicptr.rs test: remove unused import) - #161870 (bind to [::1] instead of 127.0.0.1 in documentation examples for v6 UDP methods) - #161876 (rustdoc: Correctly handle when a macro generates multiple items in `--generate-macro-expansion`)

…, r=bjorn3 Include startup crt objects on WASI for more outputs This commit adds the `crt1-reactor.o` object file in the list of pre-link-crt-objects for the `{Dynamic,Static}Dylib` output kinds for WASI targets. These previously were omitted I believe by accident and this means that the conventional `_initialize` function is not present which runs constructor functions, for example. This is additionally needed for the upcoming wasip3 target where this startup object file is more load bearing than it was previously and will become required.

…uwer Rollup of 21 pull requests Successful merges: - #158609 (Update sccache to 0.16.0) - #150075 (Implement clamp_to) - #159103 (fix(reborrow): recursive implementation) - #160562 (add target feature ABI checks for SPARC) - #160848 (std: avoid aliasing violations when wrapping opaque C types) - #161421 (Include startup crt objects on WASI for more outputs) - #161805 (Prefer ambiguous candidates when deduplicating traits in scope, so `ambiguous_glob_imported_traits` doesn't depend on import order) - #161862 (Put data segment in specified section with link_section on wasm) - #161866 (delegation: add tests fixating behavior of delegating to default trait implementations) - #161456 (reduce perf impact of scalar size checks) - #161528 (Add regression test to ensure optimal compilation) - #161666 (Print vendor instructions in `x vendor`) - #161730 (Improve type mismatch annotation for lets with block-wrapped initializers) - #161828 (Never type after-stabilization cleanup) - #161859 (Do not optimize MIR for comptime ConstFns) - #161860 (atomicptr.rs test: remove unused import) - #161870 (bind to [::1] instead of 127.0.0.1 in documentation examples for v6 UDP methods) - #161876 (rustdoc: Correctly handle when a macro generates multiple items in `--generate-macro-expansion`) - #161889 (Add link to ownership section in ptr::read docs) - #161890 (rustdoc: some clarifying comments) - #161891 (Mark `extern_item_impls` feature as incomplete) Failed merges: - #161702 (Use `drop_guard` in some places in {core,alloc,std})

…, r=bjorn3 Include startup crt objects on WASI for more outputs This commit adds the `crt1-reactor.o` object file in the list of pre-link-crt-objects for the `{Dynamic,Static}Dylib` output kinds for WASI targets. These previously were omitted I believe by accident and this means that the conventional `_initialize` function is not present which runs constructor functions, for example. This is additionally needed for the upcoming wasip3 target where this startup object file is more load bearing than it was previously and will become required.

rustbot assigned fee1-dead Aug 20, 2026

rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. labels Aug 20, 2026

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alexcrichton force-pushed the more-wasi-crt-objects branch from bab467a to db284c5 Compare August 20, 2026 19:28

rustbot added the A-run-make Area: port run-make Makefiles to rmake.rs label Aug 20, 2026

bjorn3 reviewed Aug 21, 2026

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alexcrichton force-pushed the more-wasi-crt-objects branch from db284c5 to 2188d93 Compare August 25, 2026 16:31

rustbot assigned folkertdev and unassigned fee1-dead Aug 26, 2026

rustbot assigned bjorn3 and unassigned folkertdev Aug 26, 2026

alexcrichton force-pushed the more-wasi-crt-objects branch from 2188d93 to 2089220 Compare August 26, 2026 15:29

alexcrichton closed this Aug 26, 2026

rustbot removed the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Aug 26, 2026

alexcrichton reopened this Aug 26, 2026

rustbot added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Aug 26, 2026

bjorn3 reviewed Aug 27, 2026

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Comment thread tests/run-make/wasm-symbols-not-exported/rmake.rs

bjorn3 reviewed Aug 27, 2026

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Comment thread src/tools/run-make-support/src/external_deps/rustc.rs Outdated

bjorn3 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 Aug 27, 2026

alexcrichton force-pushed the more-wasi-crt-objects branch from 2089220 to f9ad9e1 Compare August 27, 2026 15:26

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-author Status: This is awaiting some action (such as code changes or more information) from the author. labels Aug 27, 2026

JonathanBrouwer mentioned this pull request Aug 27, 2026

Rollup of 11 pull requests #161878

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GuillaumeGomez mentioned this pull request Aug 27, 2026

Rollup of 14 pull requests #161884

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oligamiq mentioned this pull request Aug 27, 2026

thread spawn is broken on wasm32-wasip1-threads for building library #146843

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JonathanBrouwer mentioned this pull request Aug 28, 2026

Rollup of 18 pull requests #161901

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JonathanBrouwer mentioned this pull request Aug 28, 2026

Rollup of 21 pull requests #161905

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JonathanBrouwer mentioned this pull request Aug 28, 2026

Rollup of 21 pull requests #161906

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