Commit f4daa80d authored by Gary Guo's avatar Gary Guo Committed by Miguel Ojeda
Browse files

rust: compile libcore with edition 2024 for 1.87+ 

Rust 1.87 (released on 2025-05-15) compiles core library with edition
2024 instead of 2021 [1]. Ensure that the edition matches libcore's
expectation to avoid potential breakage.

[ J3m3 reported in Zulip [2] that the `rust-analyzer` target was
  broken after this patch -- indeed, we need to avoid `core-cfgs`
  since those are passed to the `rust-analyzer` target.

  So, instead, I tweaked the patch to create a new `core-edition`
  variable and explicitly mention the `--edition` flag instead of
  reusing `core-cfg`s.

  In addition, pass a new argument using this new variable to
  `generate_rust_analyzer.py` so that we set the right edition there.

  By the way, for future reference: the `filter-out` change is needed
  for Rust < 1.87, since otherwise we would skip the `--edition=2021`
  we just added, ending up with no edition flag, and thus the compiler
  would default to the 2015 one.

  [2] https://rust-for-linux.zulipchat.com/#narrow/channel/291565/topic/x/near/520206547

    - Miguel ]

Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs).
Link: https://github.com/rust-lang/rust/pull/138162

 [1]
Reported-by: default avatarest31 <est31@protonmail.com>
Closes: https://github.com/Rust-for-Linux/linux/issues/1163


Signed-off-by: default avatarGary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20250517085600.2857460-1-gary@garyguo.net


Signed-off-by: default avatarMiguel Ojeda <ojeda@kernel.org>
parent df523db1

rust/Makefile

+8 −6
Original line number Diff line number Diff line
@@ -60,6 +60,8 @@ endif 
core-cfgs = \

    --cfg no_fp_fmt_parse



core-edition := $(if $(call rustc-min-version,108700),2024,2021)



# `rustc` recognizes `--remap-path-prefix` since 1.26.0, but `rustdoc` only

# since Rust 1.81.0. Moreover, `rustdoc` ICEs on out-of-tree builds since Rust

# 1.82.0 (https://github.com/rust-lang/rust/issues/138520). Thus workaround both
@@ -106,8 +108,8 @@ rustdoc-macros: $(src)/macros/lib.rs FORCE 


# Starting with Rust 1.82.0, skipping `-Wrustdoc::unescaped_backticks` should

# not be needed -- see https://github.com/rust-lang/rust/pull/128307.

rustdoc-core: private skip_flags = -Wrustdoc::unescaped_backticks

rustdoc-core: private rustc_target_flags = $(core-cfgs)

rustdoc-core: private skip_flags = --edition=2021 -Wrustdoc::unescaped_backticks

rustdoc-core: private rustc_target_flags = --edition=$(core-edition) $(core-cfgs)

rustdoc-core: $(RUST_LIB_SRC)/core/src/lib.rs FORCE

	+$(call if_changed,rustdoc)
@@ -416,7 +418,7 @@ quiet_cmd_rustc_library = $(if $(skip_clippy),RUSTC,$(RUSTC_OR_CLIPPY_QUIET)) L 
      cmd_rustc_library = \

	OBJTREE=$(abspath $(objtree)) \

	$(if $(skip_clippy),$(RUSTC),$(RUSTC_OR_CLIPPY)) \

		$(filter-out $(skip_flags),$(rust_flags) $(rustc_target_flags)) \

		$(filter-out $(skip_flags),$(rust_flags)) $(rustc_target_flags) \

		--emit=dep-info=$(depfile) --emit=obj=$@ \

		--emit=metadata=$(dir $@)$(patsubst %.o,lib%.rmeta,$(notdir $@)) \

		--crate-type rlib -L$(objtree)/$(obj) \
@@ -427,7 +429,7 @@ quiet_cmd_rustc_library = $(if $(skip_clippy),RUSTC,$(RUSTC_OR_CLIPPY_QUIET)) L 


rust-analyzer:

	$(Q)MAKEFLAGS= $(srctree)/scripts/generate_rust_analyzer.py \

		--cfgs='core=$(core-cfgs)' \

		--cfgs='core=$(core-cfgs)' $(core-edition) \

		$(realpath $(srctree)) $(realpath $(objtree)) \

		$(rustc_sysroot) $(RUST_LIB_SRC) $(if $(KBUILD_EXTMOD),$(srcroot)) \

		> rust-project.json
@@ -483,9 +485,9 @@ $(obj)/helpers/helpers.o: $(src)/helpers/helpers.c $(recordmcount_source) FORCE 
$(obj)/exports.o: private skip_gendwarfksyms = 1



$(obj)/core.o: private skip_clippy = 1

$(obj)/core.o: private skip_flags = -Wunreachable_pub

$(obj)/core.o: private skip_flags = --edition=2021 -Wunreachable_pub

$(obj)/core.o: private rustc_objcopy = $(foreach sym,$(redirect-intrinsics),--redefine-sym $(sym)=__rust$(sym))

$(obj)/core.o: private rustc_target_flags = $(core-cfgs)

$(obj)/core.o: private rustc_target_flags = --edition=$(core-edition) $(core-cfgs)

$(obj)/core.o: $(RUST_LIB_SRC)/core/src/lib.rs \

    $(wildcard $(objtree)/include/config/RUSTC_VERSION_TEXT) FORCE

	+$(call if_changed_rule,rustc_library)

scripts/generate_rust_analyzer.py

+8 −5
Original line number Diff line number Diff line
@@ -19,7 +19,7 @@ def args_crates_cfgs(cfgs): 


    return crates_cfgs



def generate_crates(srctree, objtree, sysroot_src, external_src, cfgs):

def generate_crates(srctree, objtree, sysroot_src, external_src, cfgs, core_edition):

    # Generate the configuration list.

    cfg = []

    with open(objtree / "include" / "generated" / "rustc_cfg") as fd:
@@ -35,7 +35,7 @@ def generate_crates(srctree, objtree, sysroot_src, external_src, cfgs): 
    crates_indexes = {}

    crates_cfgs = args_crates_cfgs(cfgs)



    def append_crate(display_name, root_module, deps, cfg=[], is_workspace_member=True, is_proc_macro=False):

    def append_crate(display_name, root_module, deps, cfg=[], is_workspace_member=True, is_proc_macro=False, edition="2021"):

        crate = {

            "display_name": display_name,

            "root_module": str(root_module),
@@ -43,7 +43,7 @@ def generate_crates(srctree, objtree, sysroot_src, external_src, cfgs): 
            "is_proc_macro": is_proc_macro,

            "deps": [{"crate": crates_indexes[dep], "name": dep} for dep in deps],

            "cfg": cfg,

            "edition": "2021",

            "edition": edition,

            "env": {

                "RUST_MODFILE": "This is only for rust-analyzer"

            }
@@ -61,6 +61,7 @@ def generate_crates(srctree, objtree, sysroot_src, external_src, cfgs): 
        display_name,

        deps,

        cfg=[],

        edition="2021",

    ):

        append_crate(

            display_name,
@@ -68,12 +69,13 @@ def generate_crates(srctree, objtree, sysroot_src, external_src, cfgs): 
            deps,

            cfg,

            is_workspace_member=False,

            edition=edition,

        )



    # NB: sysroot crates reexport items from one another so setting up our transitive dependencies

    # here is important for ensuring that rust-analyzer can resolve symbols. The sources of truth

    # for this dependency graph are `(sysroot_src / crate / "Cargo.toml" for crate in crates)`.

    append_sysroot_crate("core", [], cfg=crates_cfgs.get("core", []))

    append_sysroot_crate("core", [], cfg=crates_cfgs.get("core", []), edition=core_edition)

    append_sysroot_crate("alloc", ["core"])

    append_sysroot_crate("std", ["alloc", "core"])

    append_sysroot_crate("proc_macro", ["core", "std"])
@@ -177,6 +179,7 @@ def main(): 
    parser = argparse.ArgumentParser()

    parser.add_argument('--verbose', '-v', action='store_true')

    parser.add_argument('--cfgs', action='append', default=[])

    parser.add_argument("core_edition")

    parser.add_argument("srctree", type=pathlib.Path)

    parser.add_argument("objtree", type=pathlib.Path)

    parser.add_argument("sysroot", type=pathlib.Path)
@@ -193,7 +196,7 @@ def main(): 
    assert args.sysroot in args.sysroot_src.parents



    rust_project = {

        "crates": generate_crates(args.srctree, args.objtree, args.sysroot_src, args.exttree, args.cfgs),

        "crates": generate_crates(args.srctree, args.objtree, args.sysroot_src, args.exttree, args.cfgs, args.core_edition),

        "sysroot": str(args.sysroot),

    }