Derive the allocator used by tools from rustc's allocator by Zoxc · Pull Request #160372 · rust-lang/rust

Zoxc · 2026-08-02T08:14:36Z

This derives the allocator used by tools from rustc's allocator. This simplifies the feature handling a bit and would be a requirement for globally overriding the C allocator on Windows.

The overriding for rustdoc is moved from the library to the binary, which is more of a proper location given that the override must be linked into the binary.

The code in this PR is LLM written.

rustbot · 2026-08-02T08:14:40Z

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

cc @rust-lang/clippy

miri is developed in its own repository. If the Miri part of this change can be broken out, consider making this change to rust-lang/miri instead. However, if Miri needs adjusting for rustc changes, just ignore this message.

cc @rust-lang/miri

rustbot · 2026-08-02T08:14:42Z

r? @folkertdev

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folkertdev

Given that this was LLM-authored and I'm not an expert here, I feel a bit uncomfortable approving it. Who would know this code better?

View changes since this review

folkertdev · 2026-08-02T11:14:06Z

+
 use std::process::ExitCode;

+rustc_driver::override_c_allocator_in_binary!();


Suggested change

rustc_driver::override_c_allocator_in_binary!();

// Use the same allocator that rustc would use.

rustc_driver::override_c_allocator_in_binary!();

also here

folkertdev · 2026-08-02T11:19:50Z

-// A note about jemalloc: rustc uses jemalloc when built for CI and
-// distribution. The obvious way to do this is with the `#[global_allocator]`
-// mechanism. However, for complicated reasons (see
-// https://github.com/rust-lang/rust/pull/81782#issuecomment-784438001 for some
-// details) that mechanism doesn't work here. Also, we'd like to use a
-// consistent allocator across the rustc <-> llvm boundary, and
-// `#[global_allocator]` wouldn't provide that.
-//
-// Instead, we use a lower-level mechanism, namely the


it seems a bit unfortunate to throw away these comments?

They're outdated / wrong. We can use #[global_allocator] and I intend to in follow up work.

The point about providing a consistent allocator for rustc and LLVM seems to still be true?

Cc @bjorn3

They're outdated / wrong. We can use #[global_allocator] and I intend to in follow up work.

Ok. I remember at ~3 attempts to do this in the past and they always ended up with "no, actually global_allocator doesn't work", so I'm curious to see what changed :)

It would have been working since #122362 (unless I'm forgetting something).

The point about providing a consistent allocator for rustc and LLVM seems to still be true?

We want a consistent C allocator generally (for soundness), not just between rustc <-> LLVM. We also want a single allocator to keep memory usage down.

I definitely tried using #[global_allocator] after #122362, but didn't have much success. Let's try again :)

If you already override the C allocator, overriding #[global_allocator] shouldn't have any perf effect.

#[global_allocator] in rustc_driver should work now that we statically link libstd. But you did still need to link jemalloc from the main executable I think for the C allocator to be overridden.

folkertdev · 2026-08-02T11:21:58Z

@@ -0,0 +1,22 @@
+/// This macro overrides the C allocator in final binaries by linking jemalloc with the override feature enabled.


Suggested change

/// This macro overrides the C allocator in final binaries by linking jemalloc with the override feature enabled.

/// This macro overrides the C allocator in final binaries by linking jemalloc with the `override_allocator_on_supported_platforms` feature enabled.

The comments on #[global_allocator] can go here maybe, to motivate why this exists even though we have #[global_allocator].

rustbot · 2026-08-02T11:23:43Z

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

Kobzol

I guess that in general this change makes sense, because historically we used a different allocator by the tools mostly by accident, rather than explicitly, and we were losing some performance because of that.

Why is it required to override the allocator on Windows, btw?

View changes since this review

Zoxc · 2026-08-03T00:23:08Z

Why is it required to override the allocator on Windows, btw?

Windows doesn't have an official mechanism to override a symbol for the entire program, so instead we need to override it in each dylib / DLL and the binary (at link time) for programs which make use of LLVM / rustc_driver.

RalfJung · 2026-08-03T06:21:40Z

@@ -0,0 +1,22 @@
+/// This macro overrides the C allocator in final binaries by linking jemalloc with the override feature enabled.


Suggested change

/// This macro overrides the C allocator in final binaries by linking jemalloc with the override feature enabled.

/// This macro overrides the C allocator (i.e., `malloc`) in final binaries by linking jemalloc with the override feature enabled.

/// `malloc` is used by `alloc::System` on Unix targets but not Windows targets.

View changes since the review

folkertdev · 2026-08-03T08:50:06Z

r? Kobzol

rustbot · 2026-08-03T08:50:11Z

Kobzol is not on the review rotation at the moment.
They may take a while to respond.

Kobzol · 2026-08-03T09:02:59Z

@bors try @rust-timer queue profiles=Check,Debug,Opt,Doc,DocJson,Clippy

rust-timer · 2026-08-03T09:03:02Z

Error occurred while parsing comment: Cannot parse profiles: Invalid profile: DocJson. Valid values are: check, debug, opt, doc, doc-json, clippy

Derive the allocator used by tools from rustc's allocator

Kobzol · 2026-08-03T09:03:27Z

@rust-timer queue profiles=check,debug,opt,doc,doc-json,clippy

rust-bors · 2026-08-03T11:14:50Z

☀️ Try build successful (CI)
Build commit: 52500f2 (52500f2bbab097fc5e8211286b7bc5202363853f)
Base parent: 7c329d6 (7c329d6c76e11ca40c5673818ab0439c1be8962c)

rust-timer · 2026-08-03T12:45:58Z

Finished benchmarking commit (52500f2): comparison URL.

Overall result: no relevant changes - BENCHMARK(S) FAILED

Benchmarking means the PR may be perf-sensitive. Consider adding rollup=never if this change is not fit for rolling up.

@rustbot label: -S-waiting-on-perf -perf-regression

❗ ❗ ❗ ❗ ❗
Warning ⚠️: The following benchmark(s) failed to build:

Job failure

❗ ❗ ❗ ❗ ❗

Instruction count

This perf run didn't have relevant results for this metric.

Max RSS (memory usage)

Results (primary 0.6%, secondary -0.2%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	1.0%	[0.4%, 4.8%]	11
Regressions ❌ (secondary)	0.6%	[0.4%, 0.8%]	10
Improvements ✅ (primary)	-3.7%	[-3.7%, -3.7%]	1
Improvements ✅ (secondary)	-3.0%	[-5.4%, -1.2%]	3
All ❌✅ (primary)	0.6%	[-3.7%, 4.8%]	12

Cycles

Results (primary 0.1%, secondary -0.2%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	0.9%	[0.4%, 2.1%]	8
Regressions ❌ (secondary)	0.7%	[0.4%, 1.3%]	6
Improvements ✅ (primary)	-1.0%	[-2.5%, -0.6%]	6
Improvements ✅ (secondary)	-1.3%	[-2.6%, -0.5%]	5
All ❌✅ (primary)	0.1%	[-2.5%, 2.1%]	14

Binary size

This perf run didn't have relevant results for this metric.

Bootstrap: 491.018s -> 491.012s (-0.00%)
Artifact size: 390.29 MiB -> 390.29 MiB (-0.00%)

Kobzol · 2026-08-03T12:47:56Z

Oops, my bad, second try.

@bors try jobs=dist-x86_64-linux @rust-timer queue profiles=check,debug,opt,doc,doc-json,clippy

Derive the allocator used by tools from rustc's allocator try-job: dist-x86_64-linux

rust-bors · 2026-08-03T15:55:47Z

☀️ Try build successful (CI)
Build commit: 4403287 (4403287103645d716dd55787ecc442db1dd9a6e3)
Base parent: 7c329d6 (7c329d6c76e11ca40c5673818ab0439c1be8962c)

rust-timer · 2026-08-03T16:48:28Z

Finished benchmarking commit (4403287): comparison URL.

Overall result: ❌ regressions - no action needed

Benchmarking means the PR may be perf-sensitive. Consider adding rollup=never if this change is not fit for rolling up.

@rustbot label: -S-waiting-on-perf -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)	0.3%	[0.3%, 0.3%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

Results (primary -0.6%, secondary -0.5%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	0.5%	[0.4%, 0.6%]	3
Regressions ❌ (secondary)	1.6%	[0.4%, 4.6%]	4
Improvements ✅ (primary)	-1.5%	[-4.2%, -0.5%]	4
Improvements ✅ (secondary)	-1.0%	[-5.3%, -0.4%]	20
All ❌✅ (primary)	-0.6%	[-4.2%, 0.6%]	7

Cycles

Results (primary -0.4%, secondary 0.5%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	0.7%	[0.4%, 2.2%]	18
Regressions ❌ (secondary)	1.5%	[0.4%, 4.8%]	40
Improvements ✅ (primary)	-0.9%	[-2.5%, -0.4%]	36
Improvements ✅ (secondary)	-1.1%	[-3.8%, -0.4%]	25
All ❌✅ (primary)	-0.4%	[-2.5%, 2.2%]	54

Binary size

Results (secondary -0.0%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.0%	[-0.0%, -0.0%]	1
All ❌✅ (primary)	-	-	0

Bootstrap: 491.018s -> 490.844s (-0.04%)
Artifact size: 390.29 MiB -> 391.17 MiB (0.23%)

Kobzol · 2026-08-03T17:27:50Z

Okay, perf. looks good, and I went through miri and Clippy and it doesn't seem like this should break them, as they weren't using the feature directly (it was only used by bootstrap). There are still some unresolved comments about modifying the code comments a bit.

rust-log-analyzer · 2026-08-03T21:54:56Z

The job x86_64-gnu-gcc failed! Check out the build log: (web) (plain enhanced) (plain)

Click to see the possible cause of the failure (guessed by this bot)

To only update this specific test, also pass `--test-args linkage-attr/unreferenced-used-static-issue-127052.rs`

error: 1 errors occurred comparing output.
status: exit status: 0
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/linkage-attr/unreferenced-used-static-issue-127052.rs" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Z" "ignore-directory-in-diagnostics-source-blocks=/cargo" "-Z" "ignore-directory-in-diagnostics-source-blocks=/checkout/vendor" "--sysroot" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2" "-Zcodegen-backend=gcc" "--target=x86_64-unknown-linux-gnu" "--check-cfg" "cfg(test,FALSE)" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/linkage-attr/unreferenced-used-static-issue-127052" "-A" "unused" "-W" "unused_attributes" "-A" "internal_features" "-A" "incomplete_features" "-A" "unused_parens" "-A" "unused_braces" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers"
stdout: none
--- stderr -------------------------------
libgccjit.so: warning: : ‘retain’ attribute ignored [-Wattributes]
------------------------------------------

---
To only update this specific test, also pass `--test-args proc-macro/crt-static.rs`

error: 1 errors occurred comparing output.
status: exit status: 0
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/proc-macro/crt-static.rs" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Z" "ignore-directory-in-diagnostics-source-blocks=/cargo" "-Z" "ignore-directory-in-diagnostics-source-blocks=/checkout/vendor" "--sysroot" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2" "-Zcodegen-backend=gcc" "--target=x86_64-unknown-linux-gnu" "--check-cfg" "cfg(test,FALSE)" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/proc-macro/crt-static" "-A" "unused" "-W" "unused_attributes" "-A" "internal_features" "-A" "incomplete_features" "-A" "unused_parens" "-A" "unused_braces" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "--crate-type" "proc-macro" "-Ctarget-feature="
stdout: none
--- stderr -------------------------------
libgccjit.so: warning: : ‘retain’ attribute ignored [-Wattributes]
------------------------------------------

---
To only update this specific test, also pass `--test-args proc-macro/no-missing-docs.rs`

error: 1 errors occurred comparing output.
status: exit status: 0
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/proc-macro/no-missing-docs.rs" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Z" "ignore-directory-in-diagnostics-source-blocks=/cargo" "-Z" "ignore-directory-in-diagnostics-source-blocks=/checkout/vendor" "--sysroot" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2" "-Zcodegen-backend=gcc" "--target=x86_64-unknown-linux-gnu" "--check-cfg" "cfg(test,FALSE)" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/proc-macro/no-missing-docs" "-A" "unused" "-W" "unused_attributes" "-A" "internal_features" "-A" "incomplete_features" "-A" "unused_parens" "-A" "unused_braces" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers"
stdout: none
--- stderr -------------------------------
libgccjit.so: warning: : ‘retain’ attribute ignored [-Wattributes]
------------------------------------------

---
To only update this specific test, also pass `--test-args proc-macro/no-mangle-in-proc-macro-issue-111888.rs`

error: 1 errors occurred comparing output.
status: exit status: 0
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/proc-macro/no-mangle-in-proc-macro-issue-111888.rs" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Z" "ignore-directory-in-diagnostics-source-blocks=/cargo" "-Z" "ignore-directory-in-diagnostics-source-blocks=/checkout/vendor" "--sysroot" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2" "-Zcodegen-backend=gcc" "--target=x86_64-unknown-linux-gnu" "--check-cfg" "cfg(test,FALSE)" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/proc-macro/no-mangle-in-proc-macro-issue-111888" "-A" "unused" "-W" "unused_attributes" "-A" "internal_features" "-A" "incomplete_features" "-A" "unused_parens" "-A" "unused_braces" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/proc-macro/no-mangle-in-proc-macro-issue-111888/auxiliary"
stdout: none
--- stderr -------------------------------
libgccjit.so: warning: : ‘retain’ attribute ignored [-Wattributes]
------------------------------------------

---
To only update this specific test, also pass `--test-args runtime/stdout-before-main.rs`

error: 1 errors occurred comparing output.
status: exit status: 0
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/runtime/stdout-before-main.rs" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Z" "ignore-directory-in-diagnostics-source-blocks=/cargo" "-Z" "ignore-directory-in-diagnostics-source-blocks=/checkout/vendor" "--sysroot" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2" "-Zcodegen-backend=gcc" "--target=x86_64-unknown-linux-gnu" "--check-cfg" "cfg(test,FALSE)" "-O" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "-C" "prefer-dynamic" "-o" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/runtime/stdout-before-main/a" "-A" "internal_features" "-A" "incomplete_features" "-A" "unused_parens" "-A" "unused_braces" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers"
stdout: none
--- stderr -------------------------------
libgccjit.so: warning: : ‘retain’ attribute ignored [-Wattributes]
------------------------------------------

---
To only update this specific test, also pass `--test-args rust-2018/proc-macro-crate-in-paths.rs`

error: 1 errors occurred comparing output.
status: exit status: 0
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/rust-2018/proc-macro-crate-in-paths.rs" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Z" "ignore-directory-in-diagnostics-source-blocks=/cargo" "-Z" "ignore-directory-in-diagnostics-source-blocks=/checkout/vendor" "--sysroot" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2" "-Zcodegen-backend=gcc" "--target=x86_64-unknown-linux-gnu" "--check-cfg" "cfg(test,FALSE)" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/rust-2018/proc-macro-crate-in-paths" "-A" "unused" "-W" "unused_attributes" "-A" "internal_features" "-A" "incomplete_features" "-A" "unused_parens" "-A" "unused_braces" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers"
stdout: none
--- stderr -------------------------------
libgccjit.so: warning: : ‘retain’ attribute ignored [-Wattributes]
------------------------------------------

---
To only update this specific test, also pass `--test-args traits/dyn-drop-principal.rs`

error: 1 errors occurred comparing output.
status: exit status: 0
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/traits/dyn-drop-principal.rs" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Z" "ignore-directory-in-diagnostics-source-blocks=/cargo" "-Z" "ignore-directory-in-diagnostics-source-blocks=/checkout/vendor" "--sysroot" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2" "-Zcodegen-backend=gcc" "--target=x86_64-unknown-linux-gnu" "--check-cfg" "cfg(test,FALSE)" "-O" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "-C" "prefer-dynamic" "-o" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/traits/dyn-drop-principal/a" "-A" "internal_features" "-A" "incomplete_features" "-A" "unused_parens" "-A" "unused_braces" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers"
stdout: none
--- stderr -------------------------------
libgccjit.so: warning: : ‘retain’ attribute ignored [-Wattributes]
libgccjit.so: warning: : ‘retain’ attribute ignored [-Wattributes]
------------------------------------------

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For more information how to resolve CI failures of this job, visit this link.

Zoxc · 2026-08-03T22:26:12Z

I did rewrite the comments a bit.

rustbot assigned folkertdev Aug 2, 2026

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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 Aug 2, 2026

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Comment thread src/tools/rustdoc/Cargo.toml

Comment thread compiler/rustc_driver_impl/src/allocator.rs

Comment thread src/tools/miri/src/bin/miri.rs

Zoxc force-pushed the alloc-bin branch 2 times, most recently from 7c6fc1b to 79796b8 Compare August 3, 2026 00:09

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rust-bors Bot pushed a commit that referenced this pull request Aug 3, 2026

Auto merge of #160372 - Zoxc:alloc-bin, r=<try>

52500f2

Derive the allocator used by tools from rustc's allocator

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rust-bors Bot pushed a commit that referenced this pull request Aug 3, 2026

Auto merge of #160372 - Zoxc:alloc-bin, r=<try>

4403287

Derive the allocator used by tools from rustc's allocator try-job: dist-x86_64-linux

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rustbot removed the S-waiting-on-perf Status: Waiting on a perf run to be completed. label Aug 3, 2026

Derive the allocator used by tools from rustc's allocator

5aff738

Zoxc force-pushed the alloc-bin branch from 79796b8 to 5aff738 Compare August 3, 2026 20:39

RalfJung mentioned this pull request Aug 3, 2026

implement -Zllvm-target-feature #160457

Open


		use std::process::ExitCode;

		rustc_driver::override_c_allocator_in_binary!();

	rustc_driver::override_c_allocator_in_binary!();
	// Use the same allocator that rustc would use.
	rustc_driver::override_c_allocator_in_binary!();

		@@ -0,0 +1,22 @@
		/// This macro overrides the C allocator in final binaries by linking jemalloc with the override feature enabled.

	/// This macro overrides the C allocator in final binaries by linking jemalloc with the override feature enabled.
	/// This macro overrides the C allocator (i.e., `malloc`) in final binaries by linking jemalloc with the override feature enabled.
	/// `malloc` is used by `alloc::System` on Unix targets but not Windows targets.

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Zoxc commented Aug 2, 2026 • edited by rustbot Loading Uh oh! There was an error while loading. Please reload this page.

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rustbot commented Aug 2, 2026

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Zoxc commented Aug 3, 2026

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RalfJung Aug 3, 2026 • edited by rustbot Loading Uh oh! There was an error while loading. Please reload this page.

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folkertdev commented Aug 3, 2026

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rust-timer commented Aug 3, 2026

Overall result: no relevant changes - BENCHMARK(S) FAILED

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rust-timer commented Aug 3, 2026

Overall result: ❌ regressions - no action needed

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rust-log-analyzer commented Aug 3, 2026

Zoxc commented Aug 2, 2026 •

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