Use `target_family = "wasm"` instead of `target_arch = "wasm32"` by madsmtm · Pull Request #163794 · rust-lang/rust

madsmtm · 2026-10-05T09:36:05Z

This slightly improves support for the WASM64 architecture.

Concretely, ./x doc library --target wasm64-unknown-unknown now succeeds.

There shouldn't be any functional differences in this PR (the changes to library/std/src/os/fd/* were already cfg-gated out on wasm64-unknown-unknown, and the rest is gated by cfg(doc)), but the changes may become relevant if we get more Wasm64 targets in the future.

rustbot · 2026-10-05T09:36:12Z

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This slightly improves support for the WASM64 architecture.

rustbot · 2026-10-05T12:42:32Z

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

cc @bjorn3

madsmtm · 2026-10-05T12:48:05Z

CC target maintainers @hoodmane @juntyr

EDIT: Sorry, you're somewhat the wrong persons to ping here, it should've been:
CC @alexcrichton @yoshuawuyts

madsmtm · 2026-10-05T15:46:37Z

@bors try jobs=test-various

Use `target_family = "wasm"` instead of `target_arch = "wasm32"` try-job: test-various

rust-bors · 2026-10-05T17:32:25Z

☀️ Try build successful (CI)
Build commit: 2872b9a (2872b9adb4b9b56e2b0af8cb2de12d15215e8ac5)
Base parent: 602727f (602727f26878dcf9eb2999e2f58e5df1269ff47e)

alexcrichton · 2026-10-06T13:07:25Z

@bors r+

rust-bors · 2026-10-06T13:07:28Z

📌 Commit 0f7320c has been approved by alexcrichton

It is now in the queue for this repository.

…crichton Use `target_family = "wasm"` instead of `target_arch = "wasm32"` This slightly improves support for the WASM64 architecture. Concretely, `./x doc library --target wasm64-unknown-unknown` now succeeds. There shouldn't be any functional differences in this PR (the changes to `library/std/src/os/fd/*` were already cfg-gated out on `wasm64-unknown-unknown`, and the rest is gated by `cfg(doc)`), but the changes may become relevant if we get [more Wasm64 targets in the future](rust-lang#163808).

…uwer Rollup of 17 pull requests Successful merges: - #163090 (Run LLDB debuginfo tests on `x86_64-pc-windows-msvc` in CI) - #163794 (Use `target_family = "wasm"` instead of `target_arch = "wasm32"`) - #163863 (use the type name instead of `Self` in constructor paths again) - #163864 (Remove CLAUDE.md) - #163877 (Add regression test for duplicated rustdoc search results between std and core) - #162000 (peel_transparent_wrappers only works on non-1ZST) - #163257 (abby DSL: sanity checks on forall where clauses) - #163348 (perf:cache FFI safety results in improper_ctypes lint) - #163768 (Move more `rustdoc-html` tests in the right location) - #163778 (check is_indirect_first_projection when replacing in RefProp) - #163789 (cg_llvm: Avoid `as_c_char_ptr` in several places) - #163807 (Add `has_reliable_f16b` for Arm) - #163826 (Update books) - #163849 (ci: update to PowerShell 7.6.6) - #163870 (Add if-installed:auto:spellcheck to pre-push script) - #163874 (explicitly check for fresh vars in canonicalize) - #163880 (Don't add pkgs.rustc to PATH in nix dev shell)

…crichton Use `target_family = "wasm"` instead of `target_arch = "wasm32"` This slightly improves support for the WASM64 architecture. Concretely, `./x doc library --target wasm64-unknown-unknown` now succeeds. There shouldn't be any functional differences in this PR (the changes to `library/std/src/os/fd/*` were already cfg-gated out on `wasm64-unknown-unknown`, and the rest is gated by `cfg(doc)`), but the changes may become relevant if we get [more Wasm64 targets in the future](rust-lang#163808).

…uwer Rollup of 25 pull requests Successful merges: - #163090 (Run LLDB debuginfo tests on `x86_64-pc-windows-msvc` in CI) - #163806 (even more `tests/crashes` migration for `-Znext-solver`) - #162156 (add IBM f128 type) - #163508 (Document the `rustc_on_unimplemented` attribute.) - #163794 (Use `target_family = "wasm"` instead of `target_arch = "wasm32"`) - #163863 (use the type name instead of `Self` in constructor paths again) - #163864 (Remove CLAUDE.md) - #163877 (Add regression test for duplicated rustdoc search results between std and core) - #163916 (Shrink `PartialRes` and its alignment) - #149753 (On name resolution error in parameter list, suggest possible `const` typo and avoid unnecessary second error) - #152557 (Oneshot `is_ready`) - #157273 (Stabilize `optimize` attribute) - #162000 (peel_transparent_wrappers only works on non-1ZST) - #163257 (abby DSL: sanity checks on forall where clauses) - #163343 (`unit` and `[1 x unit]` layouts are incompatible on big-endian targets) - #163348 (perf:cache FFI safety results in improper_ctypes lint) - #163768 (Move more `rustdoc-html` tests in the right location) - #163778 (check is_indirect_first_projection when replacing in RefProp) - #163789 (cg_llvm: Avoid `as_c_char_ptr` in several places) - #163807 (Add `has_reliable_f16b` for Arm) - #163809 (Switch TLS implementation for wasi and bump SDK version to 34) - #163826 (Update books) - #163849 (ci: update to PowerShell 7.6.6) - #163869 (INSTALL.md: use UCRT64 instead of MINGW64 in MSYS2 section) - #163870 (Add if-installed:auto:spellcheck to pre-push script)

…crichton Use `target_family = "wasm"` instead of `target_arch = "wasm32"` This slightly improves support for the WASM64 architecture. Concretely, `./x doc library --target wasm64-unknown-unknown` now succeeds. There shouldn't be any functional differences in this PR (the changes to `library/std/src/os/fd/*` were already cfg-gated out on `wasm64-unknown-unknown`, and the rest is gated by `cfg(doc)`), but the changes may become relevant if we get [more Wasm64 targets in the future](rust-lang#163808).

…uwer Rollup of 24 pull requests Successful merges: - #163090 (Run LLDB debuginfo tests on `x86_64-pc-windows-msvc` in CI) - #163806 (even more `tests/crashes` migration for `-Znext-solver`) - #163508 (Document the `rustc_on_unimplemented` attribute.) - #163794 (Use `target_family = "wasm"` instead of `target_arch = "wasm32"`) - #163863 (use the type name instead of `Self` in constructor paths again) - #163864 (Remove CLAUDE.md) - #163877 (Add regression test for duplicated rustdoc search results between std and core) - #163916 (Shrink `PartialRes` and its alignment) - #149753 (On name resolution error in parameter list, suggest possible `const` typo and avoid unnecessary second error) - #152557 (Oneshot `is_ready`) - #157273 (Stabilize `optimize` attribute) - #162000 (peel_transparent_wrappers only works on non-1ZST) - #163257 (abby DSL: sanity checks on forall where clauses) - #163343 (`unit` and `[1 x unit]` layouts are incompatible on big-endian targets) - #163348 (perf:cache FFI safety results in improper_ctypes lint) - #163768 (Move more `rustdoc-html` tests in the right location) - #163778 (check is_indirect_first_projection when replacing in RefProp) - #163789 (cg_llvm: Avoid `as_c_char_ptr` in several places) - #163807 (Add `has_reliable_f16b` for Arm) - #163809 (Switch TLS implementation for wasi and bump SDK version to 34) - #163826 (Update books) - #163849 (ci: update to PowerShell 7.6.6) - #163869 (INSTALL.md: use UCRT64 instead of MINGW64 in MSYS2 section) - #163870 (Add if-installed:auto:spellcheck to pre-push script)

…uwer Rollup of 23 pull requests Successful merges: - #163090 (Run LLDB debuginfo tests on `x86_64-pc-windows-msvc` in CI) - #163806 (even more `tests/crashes` migration for `-Znext-solver`) - #163508 (Document the `rustc_on_unimplemented` attribute.) - #163794 (Use `target_family = "wasm"` instead of `target_arch = "wasm32"`) - #163863 (use the type name instead of `Self` in constructor paths again) - #163864 (Remove CLAUDE.md) - #163877 (Add regression test for duplicated rustdoc search results between std and core) - #163916 (Shrink `PartialRes` and its alignment) - #149753 (On name resolution error in parameter list, suggest possible `const` typo and avoid unnecessary second error) - #152557 (Oneshot `is_ready`) - #157273 (Stabilize `optimize` attribute) - #162000 (peel_transparent_wrappers only works on non-1ZST) - #163343 (`unit` and `[1 x unit]` layouts are incompatible on big-endian targets) - #163348 (perf:cache FFI safety results in improper_ctypes lint) - #163768 (Move more `rustdoc-html` tests in the right location) - #163778 (check is_indirect_first_projection when replacing in RefProp) - #163789 (cg_llvm: Avoid `as_c_char_ptr` in several places) - #163807 (Add `has_reliable_f16b` for Arm) - #163809 (Switch TLS implementation for wasi and bump SDK version to 34) - #163826 (Update books) - #163849 (ci: update to PowerShell 7.6.6) - #163869 (INSTALL.md: use UCRT64 instead of MINGW64 in MSYS2 section) - #163870 (Add if-installed:auto:spellcheck to pre-push script)

Rollup merge of #163794 - madsmtm:target_family_wasm, r=alexcrichton Use `target_family = "wasm"` instead of `target_arch = "wasm32"` This slightly improves support for the WASM64 architecture. Concretely, `./x doc library --target wasm64-unknown-unknown` now succeeds. There shouldn't be any functional differences in this PR (the changes to `library/std/src/os/fd/*` were already cfg-gated out on `wasm64-unknown-unknown`, and the rest is gated by `cfg(doc)`), but the changes may become relevant if we get [more Wasm64 targets in the future](#163808).

rust-timer · 2026-10-08T08:22:53Z

Note

This PR was benchmarked as part of triage of its containing rollup: triage URL.

Finished benchmarking commit (e5eb451): comparison URL.

Overall result: ✅ improvements - no action needed

@rustbot label: -perf-regression

Instruction count

Our most reliable metric. Used to determine the overall result above. However, even this metric can be noisy.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.1%	[-0.1%, -0.1%]	2
Improvements ✅ (secondary)	-0.1%	[-0.1%, -0.1%]	6
All ❌✅ (primary)	-0.1%	[-0.1%, -0.1%]	2

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Artifact size: 408.59 MiB -> 408.52 MiB (-0.02%)

JonathanBrouwer · 2026-10-08T16:24:17Z

This is noise, all PRs in the rollup have the same results

…uwer Rollup of 23 pull requests Successful merges: - rust-lang/rust#163090 (Run LLDB debuginfo tests on `x86_64-pc-windows-msvc` in CI) - rust-lang/rust#163806 (even more `tests/crashes` migration for `-Znext-solver`) - rust-lang/rust#163508 (Document the `rustc_on_unimplemented` attribute.) - rust-lang/rust#163794 (Use `target_family = "wasm"` instead of `target_arch = "wasm32"`) - rust-lang/rust#163863 (use the type name instead of `Self` in constructor paths again) - rust-lang/rust#163864 (Remove CLAUDE.md) - rust-lang/rust#163877 (Add regression test for duplicated rustdoc search results between std and core) - rust-lang/rust#163916 (Shrink `PartialRes` and its alignment) - rust-lang/rust#149753 (On name resolution error in parameter list, suggest possible `const` typo and avoid unnecessary second error) - rust-lang/rust#152557 (Oneshot `is_ready`) - rust-lang/rust#157273 (Stabilize `optimize` attribute) - rust-lang/rust#162000 (peel_transparent_wrappers only works on non-1ZST) - rust-lang/rust#163343 (`unit` and `[1 x unit]` layouts are incompatible on big-endian targets) - rust-lang/rust#163348 (perf:cache FFI safety results in improper_ctypes lint) - rust-lang/rust#163768 (Move more `rustdoc-html` tests in the right location) - rust-lang/rust#163778 (check is_indirect_first_projection when replacing in RefProp) - rust-lang/rust#163789 (cg_llvm: Avoid `as_c_char_ptr` in several places) - rust-lang/rust#163807 (Add `has_reliable_f16b` for Arm) - rust-lang/rust#163809 (Switch TLS implementation for wasi and bump SDK version to 34) - rust-lang/rust#163826 (Update books) - rust-lang/rust#163849 (ci: update to PowerShell 7.6.6) - rust-lang/rust#163869 (INSTALL.md: use UCRT64 instead of MINGW64 in MSYS2 section) - rust-lang/rust#163870 (Add if-installed:auto:spellcheck to pre-push script)

madsmtm added O-wasm Target: WASM (WebAssembly), http://webassembly.org/ T-libs Relevant to the library team, which will review and decide on the PR/issue. labels Oct 5, 2026

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rustbot added A-compiler-builtins Area: compiler-builtins (https://github.com/rust-lang/compiler-builtins) O-unix Operating system: Unix-like S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Oct 5, 2026

rustbot assigned ChrisDenton Oct 5, 2026

madsmtm force-pushed the target_family_wasm branch from 44be1ed to f6f3cc7 Compare October 5, 2026 09:37

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Use target_family = "wasm" instead of target_arch = "wasm32"

0f7320c

This slightly improves support for the WASM64 architecture.

madsmtm force-pushed the target_family_wasm branch from f6f3cc7 to 0f7320c Compare October 5, 2026 12:42

hoodmane reviewed Oct 5, 2026

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rust-bors Bot pushed a commit that referenced this pull request Oct 5, 2026

Auto merge of #163794 - madsmtm:target_family_wasm, r=<try>

2872b9a

Use `target_family = "wasm"` instead of `target_arch = "wasm32"` try-job: test-various

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 Oct 6, 2026

JonathanBrouwer mentioned this pull request Oct 6, 2026

Rollup of 17 pull requests #163884

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JonathanBrouwer mentioned this pull request Oct 7, 2026

Rollup of 25 pull requests #163919

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Rollup of 24 pull requests #163934

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Rollup of 23 pull requests #163957

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rust-bors Bot merged commit 9be05cc into rust-lang:main Oct 8, 2026
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rustbot added this to the 1.101.0 milestone Oct 8, 2026

madsmtm deleted the target_family_wasm branch October 8, 2026 00:47

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Toolchain upgrade to nightly-2026-10-09 flux-rs/flux#1811

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Use `target_family = "wasm"` instead of `target_arch = "wasm32"` - #163794

Use `target_family = "wasm"` instead of `target_arch = "wasm32"`#163794
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