Update the minimum external LLVM to 20 #145071

cuviper · 2025-08-07T22:27:02Z

With this change, we'll have stable support for LLVM 20 and 21.
For reference, the previous increase to LLVM 19 was #139275.

cc @rust-lang/wg-llvm
r? nikic

compiler/rustc_codegen_ssa/src/traits/builder.rs

nikic · 2025-08-08T07:54:06Z

src/ci/github-actions/jobs.yml

-      IMAGE: x86_64-gnu-llvm-19
-      DOCKER_SCRIPT: x86_64-gnu-llvm3.sh
-    <<: *job-linux-4c
-


Not directly related to this PR, but does this mean we're actually running different jobs in PR CI and auto CI? PR CI runs some on aarch64, but here everything uses x86_64.

Yes, #141576 only changed the PR side. (cc @marcoieni)
There was also a zulip discussion here.

yes. That's true. If you think it would be better to use the same runner in the auto build, we can switch to aarch64 in the auto build, too 👍

tests/assembly-llvm/x86_64-cmp.rs

nikic · 2025-08-08T07:56:54Z

r=me once it's time.

rustbot · 2025-09-16T19:01:26Z

This PR changes how LLVM is built. Consider updating src/bootstrap/download-ci-llvm-stamp.

Some changes occurred in compiler/rustc_codegen_ssa

cc @WaffleLapkin

Rollup of 14 pull requests Successful merges: - #142807 (libtest: expose --fail-fast as an unstable command-line option) - #144871 (Stabilize `btree_entry_insert` feature) - #145071 (Update the minimum external LLVM to 20) - #145181 (remove FIXME block from `has_significant_drop`, it never encounters inference variables) - #145660 (initial implementation of the darwin_objc unstable feature) - #145838 (don't apply temporary lifetime extension rules to non-extended `super let`) - #146259 (Suggest removing Box::new instead of unboxing it) - #146410 (Iterator repeat: no infinite loop for `last` and `count`) - #146460 (Add tidy readme) - #146552 (StateTransform: Do not renumber resume local.) - #146564 (Remove Rvalue::Len again.) - #146581 (Detect attempt to use var-args in closure) - #146588 (tests/run-make: Update list of statically linked musl targets) - #146631 (cg_llvm: Replace some DIBuilder wrappers with LLVM-C API bindings (part 3)) r? `@ghost` `@rustbot` modify labels: rollup

Rollup merge of #145071 - cuviper:min-llvm-20, r=nikic Update the minimum external LLVM to 20 With this change, we'll have stable support for LLVM 20 and 21. For reference, the previous increase to LLVM 19 was #139275. cc ```@rust-lang/wg-llvm``` r? nikic

cg_llvm: Move target machine command-line quoting from C++ to Rust When this code was introduced in #130446 and #131805, it was complicated by the need to maintain compatibility with earlier versions of LLVM. Now that LLVM 20 is the baseline (#145071), we can do all of the quoting in pure Rust code, and pass two flat strings to LLVM to be used as-is. --- In this PR, my priority has been to preserve the existing behaviour as much as possible, without worrying too much about what the behaviour *should* be. (Though I did avoid a leading space before the first argument.)

cg_llvm: Move target machine command-line quoting from C++ to Rust When this code was introduced in rust-lang/rust#130446 and rust-lang/rust#131805, it was complicated by the need to maintain compatibility with earlier versions of LLVM. Now that LLVM 20 is the baseline (rust-lang/rust#145071), we can do all of the quoting in pure Rust code, and pass two flat strings to LLVM to be used as-is. --- In this PR, my priority has been to preserve the existing behaviour as much as possible, without worrying too much about what the behaviour *should* be. (Though I did avoid a leading space before the first argument.)

Rollup of 14 pull requests Successful merges: - rust-lang/rust#142807 (libtest: expose --fail-fast as an unstable command-line option) - rust-lang/rust#144871 (Stabilize `btree_entry_insert` feature) - rust-lang/rust#145071 (Update the minimum external LLVM to 20) - rust-lang/rust#145181 (remove FIXME block from `has_significant_drop`, it never encounters inference variables) - rust-lang/rust#145660 (initial implementation of the darwin_objc unstable feature) - rust-lang/rust#145838 (don't apply temporary lifetime extension rules to non-extended `super let`) - rust-lang/rust#146259 (Suggest removing Box::new instead of unboxing it) - rust-lang/rust#146410 (Iterator repeat: no infinite loop for `last` and `count`) - rust-lang/rust#146460 (Add tidy readme) - rust-lang/rust#146552 (StateTransform: Do not renumber resume local.) - rust-lang/rust#146564 (Remove Rvalue::Len again.) - rust-lang/rust#146581 (Detect attempt to use var-args in closure) - rust-lang/rust#146588 (tests/run-make: Update list of statically linked musl targets) - rust-lang/rust#146631 (cg_llvm: Replace some DIBuilder wrappers with LLVM-C API bindings (part 3)) r? `@ghost` `@rustbot` modify labels: rollup

cg_llvm: Move target machine command-line quoting from C++ to Rust When this code was introduced in rust-lang#130446 and rust-lang#131805, it was complicated by the need to maintain compatibility with earlier versions of LLVM. Now that LLVM 20 is the baseline (rust-lang#145071), we can do all of the quoting in pure Rust code, and pass two flat strings to LLVM to be used as-is. --- In this PR, my priority has been to preserve the existing behaviour as much as possible, without worrying too much about what the behaviour *should* be. (Though I did avoid a leading space before the first argument.)

Use `LLVMDisposeTargetMachine` After bumping the minimum LLVM version to 20 (rust-lang#145071), we no longer need to run any custom code when disposing of a TargetMachine, so we can just use the upstream LLVM-C function.

Rollup merge of #147015 - Zalathar:dispose-tm, r=lqd Use `LLVMDisposeTargetMachine` After bumping the minimum LLVM version to 20 (#145071), we no longer need to run any custom code when disposing of a TargetMachine, so we can just use the upstream LLVM-C function.

Use `LLVMDisposeTargetMachine` After bumping the minimum LLVM version to 20 (rust-lang/rust#145071), we no longer need to run any custom code when disposing of a TargetMachine, so we can just use the upstream LLVM-C function.

Rollup of 14 pull requests Successful merges: - rust-lang/rust#142807 (libtest: expose --fail-fast as an unstable command-line option) - rust-lang/rust#144871 (Stabilize `btree_entry_insert` feature) - rust-lang/rust#145071 (Update the minimum external LLVM to 20) - rust-lang/rust#145181 (remove FIXME block from `has_significant_drop`, it never encounters inference variables) - rust-lang/rust#145660 (initial implementation of the darwin_objc unstable feature) - rust-lang/rust#145838 (don't apply temporary lifetime extension rules to non-extended `super let`) - rust-lang/rust#146259 (Suggest removing Box::new instead of unboxing it) - rust-lang/rust#146410 (Iterator repeat: no infinite loop for `last` and `count`) - rust-lang/rust#146460 (Add tidy readme) - rust-lang/rust#146552 (StateTransform: Do not renumber resume local.) - rust-lang/rust#146564 (Remove Rvalue::Len again.) - rust-lang/rust#146581 (Detect attempt to use var-args in closure) - rust-lang/rust#146588 (tests/run-make: Update list of statically linked musl targets) - rust-lang/rust#146631 (cg_llvm: Replace some DIBuilder wrappers with LLVM-C API bindings (part 3)) r? `@ghost` `@rustbot` modify labels: rollup

cg_llvm: Move target machine command-line quoting from C++ to Rust When this code was introduced in rust-lang/rust#130446 and rust-lang/rust#131805, it was complicated by the need to maintain compatibility with earlier versions of LLVM. Now that LLVM 20 is the baseline (rust-lang/rust#145071), we can do all of the quoting in pure Rust code, and pass two flat strings to LLVM to be used as-is. --- In this PR, my priority has been to preserve the existing behaviour as much as possible, without worrying too much about what the behaviour *should* be. (Though I did avoid a leading space before the first argument.)

Rollup of 14 pull requests Successful merges: - rust-lang#142807 (libtest: expose --fail-fast as an unstable command-line option) - rust-lang#144871 (Stabilize `btree_entry_insert` feature) - rust-lang#145071 (Update the minimum external LLVM to 20) - rust-lang#145181 (remove FIXME block from `has_significant_drop`, it never encounters inference variables) - rust-lang#145660 (initial implementation of the darwin_objc unstable feature) - rust-lang#145838 (don't apply temporary lifetime extension rules to non-extended `super let`) - rust-lang#146259 (Suggest removing Box::new instead of unboxing it) - rust-lang#146410 (Iterator repeat: no infinite loop for `last` and `count`) - rust-lang#146460 (Add tidy readme) - rust-lang#146552 (StateTransform: Do not renumber resume local.) - rust-lang#146564 (Remove Rvalue::Len again.) - rust-lang#146581 (Detect attempt to use var-args in closure) - rust-lang#146588 (tests/run-make: Update list of statically linked musl targets) - rust-lang#146631 (cg_llvm: Replace some DIBuilder wrappers with LLVM-C API bindings (part 3)) r? `@ghost` `@rustbot` modify labels: rollup

cg_llvm: Move target machine command-line quoting from C++ to Rust When this code was introduced in rust-lang#130446 and rust-lang#131805, it was complicated by the need to maintain compatibility with earlier versions of LLVM. Now that LLVM 20 is the baseline (rust-lang#145071), we can do all of the quoting in pure Rust code, and pass two flat strings to LLVM to be used as-is. --- In this PR, my priority has been to preserve the existing behaviour as much as possible, without worrying too much about what the behaviour *should* be. (Though I did avoid a leading space before the first argument.)

Rollup of 14 pull requests Successful merges: - rust-lang#142807 (libtest: expose --fail-fast as an unstable command-line option) - rust-lang#144871 (Stabilize `btree_entry_insert` feature) - rust-lang#145071 (Update the minimum external LLVM to 20) - rust-lang#145181 (remove FIXME block from `has_significant_drop`, it never encounters inference variables) - rust-lang#145660 (initial implementation of the darwin_objc unstable feature) - rust-lang#145838 (don't apply temporary lifetime extension rules to non-extended `super let`) - rust-lang#146259 (Suggest removing Box::new instead of unboxing it) - rust-lang#146410 (Iterator repeat: no infinite loop for `last` and `count`) - rust-lang#146460 (Add tidy readme) - rust-lang#146552 (StateTransform: Do not renumber resume local.) - rust-lang#146564 (Remove Rvalue::Len again.) - rust-lang#146581 (Detect attempt to use var-args in closure) - rust-lang#146588 (tests/run-make: Update list of statically linked musl targets) - rust-lang#146631 (cg_llvm: Replace some DIBuilder wrappers with LLVM-C API bindings (part 3)) r? `@ghost` `@rustbot` modify labels: rollup

cg_llvm: Move target machine command-line quoting from C++ to Rust When this code was introduced in rust-lang#130446 and rust-lang#131805, it was complicated by the need to maintain compatibility with earlier versions of LLVM. Now that LLVM 20 is the baseline (rust-lang#145071), we can do all of the quoting in pure Rust code, and pass two flat strings to LLVM to be used as-is. --- In this PR, my priority has been to preserve the existing behaviour as much as possible, without worrying too much about what the behaviour *should* be. (Though I did avoid a leading space before the first argument.)

Rollup of 14 pull requests Successful merges: - rust-lang/rust#142807 (libtest: expose --fail-fast as an unstable command-line option) - rust-lang/rust#144871 (Stabilize `btree_entry_insert` feature) - rust-lang/rust#145071 (Update the minimum external LLVM to 20) - rust-lang/rust#145181 (remove FIXME block from `has_significant_drop`, it never encounters inference variables) - rust-lang/rust#145660 (initial implementation of the darwin_objc unstable feature) - rust-lang/rust#145838 (don't apply temporary lifetime extension rules to non-extended `super let`) - rust-lang/rust#146259 (Suggest removing Box::new instead of unboxing it) - rust-lang/rust#146410 (Iterator repeat: no infinite loop for `last` and `count`) - rust-lang/rust#146460 (Add tidy readme) - rust-lang/rust#146552 (StateTransform: Do not renumber resume local.) - rust-lang/rust#146564 (Remove Rvalue::Len again.) - rust-lang/rust#146581 (Detect attempt to use var-args in closure) - rust-lang/rust#146588 (tests/run-make: Update list of statically linked musl targets) - rust-lang/rust#146631 (cg_llvm: Replace some DIBuilder wrappers with LLVM-C API bindings (part 3)) r? `@ghost` `@rustbot` modify labels: rollup

cg_llvm: Move target machine command-line quoting from C++ to Rust When this code was introduced in rust-lang/rust#130446 and rust-lang/rust#131805, it was complicated by the need to maintain compatibility with earlier versions of LLVM. Now that LLVM 20 is the baseline (rust-lang/rust#145071), we can do all of the quoting in pure Rust code, and pass two flat strings to LLVM to be used as-is. --- In this PR, my priority has been to preserve the existing behaviour as much as possible, without worrying too much about what the behaviour *should* be. (Though I did avoid a leading space before the first argument.)

This MR contains the following updates: | Package | Update | Change | |---|---|---| | [rust](https://github.com/rust-lang/rust) | minor | `1.91.1` -> `1.92.0` | MR created with the help of [el-capitano/tools/renovate-bot](https://gitlab.com/el-capitano/tools/renovate-bot). **Proposed changes to behavior should be submitted there as MRs.** --- ### Release Notes <details> <summary>rust-lang/rust (rust)</summary> ### [`v1.92.0`](https://github.com/rust-lang/rust/blob/HEAD/RELEASES.md#Version-1920-2025-12-11) [Compare Source](rust-lang/rust@1.91.1...1.92.0) \========================== <a id="1.92.0-Language"></a> ## Language - [Document `MaybeUninit` representation and validity](rust-lang/rust#140463) - [Allow `&raw [mut | const]` for union field in safe code](rust-lang/rust#141469) - [Prefer item bounds of associated types over where-bounds for auto-traits and `Sized`](rust-lang/rust#144064) - [Do not materialize `X` in `[X; 0]` when `X` is unsizing a const](rust-lang/rust#145277) - [Support combining `#[track_caller]` and `#[no_mangle]` (requires every declaration specifying `#[track_caller]` as well)](rust-lang/rust#145724) - [Make never type lints `never_type_fallback_flowing_into_unsafe` and `dependency_on_unit_never_type_fallback` deny-by-default](rust-lang/rust#146167) - [Allow specifying multiple bounds for same associated item, except in trait objects](rust-lang/rust#146593) - [Slightly strengthen higher-ranked region handling in coherence](rust-lang/rust#146725) - [The `unused_must_use` lint no longer warns on `Result<(), Uninhabited>` (for instance, `Result<(), !>`), or `ControlFlow<Uninhabited, ()>`](rust-lang/rust#147382). This avoids having to check for an error that can never happen. <a id="1.92.0-Compiler"></a> ## Compiler - [Make `mips64el-unknown-linux-muslabi64` link dynamically](rust-lang/rust#146858) - [Remove current code for embedding command-line args in PDB](rust-lang/rust#147022) Command-line information is typically not needed by debugging tools, and the removed code was causing problems for incremental builds even on targets that don't use PDB debuginfo. <a id="1.92.0-Libraries"></a> ## Libraries - [Specialize `Iterator::eq{_by}` for `TrustedLen` iterators](rust-lang/rust#137122) - [Simplify `Extend` for tuples](rust-lang/rust#138799) - [Added details to `Debug` for `EncodeWide`](rust-lang/rust#140153). - [`iter::Repeat::last`](rust-lang/rust#147258) and [`count`](rust-lang/rust#146410) will now panic, rather than looping infinitely. <a id="1.92.0-Stabilized-APIs"></a> ## Stabilized APIs - [`NonZero<u{N}>::div_ceil`](https://doc.rust-lang.org/stable/std/num/struct.NonZero.html#method.div_ceil) - [`Location::file_as_c_str`](https://doc.rust-lang.org/stable/std/panic/struct.Location.html#method.file_as_c_str) - [`RwLockWriteGuard::downgrade`](https://doc.rust-lang.org/stable/std/sync/struct.RwLockWriteGuard.html#method.downgrade) - [`Box::new_zeroed`](https://doc.rust-lang.org/stable/std/boxed/struct.Box.html#method.new_zeroed) - [`Box::new_zeroed_slice`](https://doc.rust-lang.org/stable/std/boxed/struct.Box.html#method.new_zeroed_slice) - [`Rc::new_zeroed`](https://doc.rust-lang.org/stable/std/rc/struct.Rc.html#method.new_zeroed) - [`Rc::new_zeroed_slice`](https://doc.rust-lang.org/stable/std/rc/struct.Rc.html#method.new_zeroed_slice) - [`Arc::new_zeroed`](https://doc.rust-lang.org/stable/std/sync/struct.Arc.html#method.new_zeroed) - [`Arc::new_zeroed_slice`](https://doc.rust-lang.org/stable/std/sync/struct.Arc.html#method.new_zeroed_slice) - [`btree_map::Entry::insert_entry`](https://doc.rust-lang.org/stable/std/collections/btree_map/enum.Entry.html#method.insert_entry) - [`btree_map::VacantEntry::insert_entry`](https://doc.rust-lang.org/stable/std/collections/btree_map/struct.VacantEntry.html#method.insert_entry) - [`impl Extend<proc_macro::Group> for proc_macro::TokenStream`](https://doc.rust-lang.org/stable/proc_macro/struct.TokenStream.html#impl-Extend%3CGroup%3E-for-TokenStream) - [`impl Extend<proc_macro::Literal> for proc_macro::TokenStream`](https://doc.rust-lang.org/stable/proc_macro/struct.TokenStream.html#impl-Extend%3CLiteral%3E-for-TokenStream) - [`impl Extend<proc_macro::Punct> for proc_macro::TokenStream`](https://doc.rust-lang.org/stable/proc_macro/struct.TokenStream.html#impl-Extend%3CPunct%3E-for-TokenStream) - [`impl Extend<proc_macro::Ident> for proc_macro::TokenStream`](https://doc.rust-lang.org/stable/proc_macro/struct.TokenStream.html#impl-Extend%3CIdent%3E-for-TokenStream) These previously stable APIs are now stable in const contexts: - [`<[_]>::rotate_left`](https://doc.rust-lang.org/stable/std/primitive.slice.html#method.rotate_left) - [`<[_]>::rotate_right`](https://doc.rust-lang.org/stable/std/primitive.slice.html#method.rotate_right) <a id="1.92.0-Cargo"></a> ## Cargo - [Added a new chapter](rust-lang/cargo#16119) to the Cargo book, ["Optimizing Build Performance"](https://doc.rust-lang.org/stable/cargo/guide/build-performance.html). <a id="1.92.0-Rustdoc"></a> ## Rustdoc - [If a trait item appears in rustdoc search, hide the corresponding impl items](rust-lang/rust#145898). Previously a search for "last" would show both `Iterator::last` as well as impl methods like `std::vec::IntoIter::last`. Now these impl methods will be hidden, freeing up space for inherent methods like `BTreeSet::last`. - [Relax rules for identifiers in search](rust-lang/rust#147860). Previously you could only search for identifiers that were valid in rust code, now searches only need to be valid as part of an identifier. For example, you can now perform a search that starts with a digit. <a id="1.92.0-Compatibility-Notes"></a> ## Compatibility Notes - [Fix backtraces with `-C panic=abort` on Linux by generating unwind tables by default](rust-lang/rust#143613). Build with `-C force-unwind-tables=no` to keep omitting unwind tables. * As part of the larger effort refactoring compiler built-in attributes and their diagnostics, [the future-compatibility lint `invalid_macro_export_arguments` is upgraded to deny-by-default and will be reported in dependencies too.](rust-lang/rust#143857) * [Update the minimum external LLVM to 20](rust-lang/rust#145071) * [Prevent downstream `impl DerefMut for Pin<LocalType>`](rust-lang/rust#145608) * [Don't apply temporary lifetime extension rules to the arguments of non-extended `pin!` and formatting macros](rust-lang/rust#145838) </details> --- ### Configuration 📅 **Schedule**: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined). 🚦 **Automerge**: Disabled by config. Please merge this manually once you are satisfied. ♻ **Rebasing**: Whenever MR becomes conflicted, or you tick the rebase/retry checkbox. 🔕 **Ignore**: Close this MR and you won't be reminded about this update again. --- - [ ] If you want to rebase/retry this MR, check this box --- This MR has been generated by [Renovate Bot](https://github.com/renovatebot/renovate).

rustbot assigned nikic Aug 7, 2025