bors 52882f6522 Auto merge of #119899 - onur-ozkan:redesign-stage0-std, r=albertlarsan68,jieyouxu,mark-simulacrum,kobzol,jyn514,Noratrieb,WaffleLapkin,RalfJung,bjorn3 ... redesign stage 0 std ### Summary **Blog post: https://blog.rust-lang.org/inside-rust/2025/05/29/redesigning-the-initial-bootstrap-sequence/** This PR changes how bootstrap builds the stage 1 compiler by switching to precompiled stage 0 standard library instead of building the in-tree one. The goal was to update bootstrap to use the beta standard library at stage 0 rather than compiling it from source (see the motivation at https://github.com/rust-lang/compiler-team/issues/619). Previously, to build a stage 1 compiler bootstrap followed this path: ``` download stage0 compiler -> build in-tree std -> compile stage1 compiler with in-tree std ``` With this PR, the new path is: ``` download stage0 compiler -> compile stage1 compiler with precompiled stage0 std ``` This also means that `cfg(bootstrap)`/`cfg(not(bootstrap))` is no longer needed for library development. ### Building "library" Since stage0 `std` is no longer in-tree `x build/test/check library --stage 0` is now no-op. The minimum supported stage to build `std` is now 1. For the same reason, default stage values in the library profile is no longer 0. Because building the in-tree library now requires a stage1 compiler, I highly recommend library developers to enable `download-rustc` to speed up compilation time. <hr> **Blog post: https://blog.rust-lang.org/inside-rust/2025/05/29/redesigning-the-initial-bootstrap-sequence/** If you encounter a bug or unexpected results please open a topic in the [#t-infra/bootstrap](https://rust-lang.zulipchat.com/#narrow/channel/326414-t-infra.2Fbootstrap) Zulip channel or create a [bootstrap issue](https://github.com/rust-lang/rust/issues/new?template=bootstrap.md). (Review thread: https://rust-lang.zulipchat.com/#narrow/channel/326414-t-infra.2Fbootstrap/topic/Review.20thread.3A.20stage.200.20redesign.20PR/with/508271433) ~~Blocked on https://github.com/rust-lang/rust/pull/122709~~ try-job: dist-x86_64-linux try-job: `x86_64-msvc*` try-job: `x86_64-apple-*` try-job: `aarch64-apple` try-job: x86_64-gnu try-job: `x86_64-gnu-llvm*`		2025-06-02 07:49:18 +00:00
..
analyze_source_file	Be more accurate about calculating display_col from a BytePos	2024-07-18 20:08:38 +00:00
edit_distance	update cfg(bootstrap)	2025-01-08 21:26:39 +01:00
source_map	Take into-account -Zremap-path-scope when embedding filenames	2025-05-05 19:45:34 +02:00
symbol	Allow drivers to supply a list of extra symbols to intern	2025-04-10 13:39:23 +00:00
analyze_source_file.rs	handle cfg bootstrap on compiler and miri	2025-05-30 21:03:54 +03:00
caching_source_map_view.rs	tree-wide: parallel: Fully removed all Lrc, replaced with Arc	2025-02-03 13:25:57 +03:00
def_id.rs	Move hashes from rustc_data_structure to rustc_hashes so they can be shared with rust-analyzer	2025-02-16 16:18:30 -05:00
edit_distance.rs	Use abs_diff where applicable	2025-03-27 18:29:06 +00:00
edition.rs	Unify the format of rustc cli flags	2025-04-24 12:54:40 +08:00
fatal_error.rs	Auto merge of #117557 - Zoxc:panic-prio, r=petrochenkov	2023-11-09 00:39:02 +00:00
hygiene.rs	Move in_external_macro to SyntaxContext	2025-04-28 20:14:58 -04:00
lib.rs	handle cfg bootstrap on compiler and miri	2025-05-30 21:03:54 +03:00
profiling.rs	Reformat use declarations.	2024-07-29 08:26:52 +10:00
source_map.rs	Take into-account -Zremap-path-scope when embedding filenames	2025-05-05 19:45:34 +02:00
span_encoding.rs	Optimize the codegen for Span::from_expansion	2025-04-30 11:38:09 -04:00
symbol.rs	slice.get(i) should use a slice projection in MIR, like slice[i] does	2025-05-30 12:04:41 -07:00
tests.rs	add unstable support for outputting file checksums for use in cargo	2024-10-01 21:23:20 -06:00