std: include dlmalloc for all non-wasi Wasm targets#153686
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Twey wants to merge 2 commits intorust-lang:mainfrom
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std: include dlmalloc for all non-wasi Wasm targets#153686Twey wants to merge 2 commits intorust-lang:mainfrom
std: include dlmalloc for all non-wasi Wasm targets#153686Twey wants to merge 2 commits intorust-lang:mainfrom
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Currently, building std for a custom Wasm target with an OS other than `unknown` will fail, because `sys/alloc/mod.rs` will attempt to use `sys/alloc/wasm.rs`, the dlmalloc-based allocator used on `wasm32-unknown-unknown`. However, currently dlmalloc is only pulled in when `target_os = "unknown"`. Instead, we should make `Cargo.toml` and `alloc/mod.rs` match: either - disable `wasm.rs` in `alloc/mod.rs` where `not(target_os = "unknown")`, or - pull in `dlmalloc` for all Wasm targets with `target_family = "wasm32"` that aren't covered by the [upper branches of `alloc/mod.rs`](https://github.com/rust-lang/rust/blob/main/library/std/src/sys/alloc/mod.rs#L72-L100). This PR takes the latter approach, because it allows more code to compile without a custom allocator.
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`std`: include `dlmalloc` for all non-wasi Wasm targets Currently, building std for a custom Wasm target with an OS other than `unknown` will fail, because `sys/alloc/mod.rs` will attempt to use `sys/alloc/wasm.rs`, the dlmalloc-based allocator used on `wasm32-unknown-unknown`. However, currently dlmalloc is only pulled in when `target_os = "unknown"`. Instead, we should make `Cargo.toml` and `alloc/mod.rs` match: either - disable `wasm.rs` in `alloc/mod.rs` where `not(target_os = "unknown")`, or - pull in `dlmalloc` for all Wasm targets with `target_family = "wasm32"` that aren't covered by the [upper branches of `alloc/mod.rs`](https://github.com/rust-lang/rust/blob/main/library/std/src/sys/alloc/mod.rs#L72-L100). This PR takes the latter approach, because it allows more code to compile without a custom allocator.
JonathanBrouwer
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Mar 22, 2026
`std`: include `dlmalloc` for all non-wasi Wasm targets Currently, building std for a custom Wasm target with an OS other than `unknown` will fail, because `sys/alloc/mod.rs` will attempt to use `sys/alloc/wasm.rs`, the dlmalloc-based allocator used on `wasm32-unknown-unknown`. However, currently dlmalloc is only pulled in when `target_os = "unknown"`. Instead, we should make `Cargo.toml` and `alloc/mod.rs` match: either - disable `wasm.rs` in `alloc/mod.rs` where `not(target_os = "unknown")`, or - pull in `dlmalloc` for all Wasm targets with `target_family = "wasm32"` that aren't covered by the [upper branches of `alloc/mod.rs`](https://github.com/rust-lang/rust/blob/main/library/std/src/sys/alloc/mod.rs#L72-L100). This PR takes the latter approach, because it allows more code to compile without a custom allocator.
JonathanBrouwer
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Mar 23, 2026
`std`: include `dlmalloc` for all non-wasi Wasm targets Currently, building std for a custom Wasm target with an OS other than `unknown` will fail, because `sys/alloc/mod.rs` will attempt to use `sys/alloc/wasm.rs`, the dlmalloc-based allocator used on `wasm32-unknown-unknown`. However, currently dlmalloc is only pulled in when `target_os = "unknown"`. Instead, we should make `Cargo.toml` and `alloc/mod.rs` match: either - disable `wasm.rs` in `alloc/mod.rs` where `not(target_os = "unknown")`, or - pull in `dlmalloc` for all Wasm targets with `target_family = "wasm32"` that aren't covered by the [upper branches of `alloc/mod.rs`](https://github.com/rust-lang/rust/blob/main/library/std/src/sys/alloc/mod.rs#L72-L100). This PR takes the latter approach, because it allows more code to compile without a custom allocator.
JonathanBrouwer
added a commit
to JonathanBrouwer/rust
that referenced
this pull request
Mar 23, 2026
`std`: include `dlmalloc` for all non-wasi Wasm targets Currently, building std for a custom Wasm target with an OS other than `unknown` will fail, because `sys/alloc/mod.rs` will attempt to use `sys/alloc/wasm.rs`, the dlmalloc-based allocator used on `wasm32-unknown-unknown`. However, currently dlmalloc is only pulled in when `target_os = "unknown"`. Instead, we should make `Cargo.toml` and `alloc/mod.rs` match: either - disable `wasm.rs` in `alloc/mod.rs` where `not(target_os = "unknown")`, or - pull in `dlmalloc` for all Wasm targets with `target_family = "wasm32"` that aren't covered by the [upper branches of `alloc/mod.rs`](https://github.com/rust-lang/rust/blob/main/library/std/src/sys/alloc/mod.rs#L72-L100). This PR takes the latter approach, because it allows more code to compile without a custom allocator.
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Currently, building std for a custom Wasm target with an OS other than
unknownwill fail, becausesys/alloc/mod.rswill attempt to usesys/alloc/wasm.rs, the dlmalloc-based allocator used onwasm32-unknown-unknown. However, currently dlmalloc is only pulled in whentarget_os = "unknown".Instead, we should make
Cargo.tomlandalloc/mod.rsmatch: eitherwasm.rsinalloc/mod.rswherenot(target_os = "unknown"), ordlmallocfor all Wasm targets withtarget_family = "wasm32"that aren't covered by the upper branches ofalloc/mod.rs.This PR takes the latter approach, because it allows more code to compile without a custom allocator.