Skip to content

non-pub function no longer compiled in debug profile, causing link errors on thumbv7em-none-eabihf with defmt #131164

Closed
Closed
non-pub function no longer compiled in debug profile, causing link errors on thumbv7em-none-eabihf with defmt#131164
Labels
A-LLVMArea: Code generation parts specific to LLVM. Both correctness bugs and optimization-related issues.A-linkageArea: linking into static, shared libraries and binariesC-bugCategory: This is a bug.P-highHigh priorityS-has-mcveStatus: A Minimal Complete and Verifiable Example has been found for this issueT-compilerRelevant to the compiler team, which will review and decide on the PR/issue.regression-from-stable-to-betaPerformance or correctness regression from stable to beta.
Milestone
1.82.0

Description

@jonathanpallant
jonathanpallant
opened on Oct 2, 2024

Code

I tried this code:

$ git clone https://github.com/ferrous-systems/rust-exercises.git
$ cd rust-exercises
$ git checkout v1.17.0
$ cd nrf52_code/radio_app
$ rustup target add thumbv7em-none-eabihf --toolchain=nightly
$ cargo install flip-link (or change `.cargo/config.toml` to not use flip-link - either is fine)
$ cargo +nightly build

I expected to see this happen:

The binaries build like, they do on stable.

Instead, this happened:

  = note: rust-lld: error: /Users/jonathan/Documents/clients/training/open-rust-embedded-2024-10-02/rust-exercises-v1.17.0/nrf52-code/radio-app/target/thumbv7em-none-eabihf/debug/build/defmt-36a2ab5d209daca3/out/defmt.x:7: symbol not found: __defmt_default_panic
          rust-lld: error: /Users/jonathan/Documents/clients/training/open-rust-embedded-2024-10-02/rust-exercises-v1.17.0/nrf52-code/radio-app/target/thumbv7em-none-eabihf/debug/build/defmt-36a2ab5d209daca3/out/defmt.x:7: symbol not found: __defmt_default_panic
          rust-lld: error: /Users/jonathan/Documents/clients/training/open-rust-embedded-2024-10-02/rust-exercises-v1.17.0/nrf52-code/radio-app/target/thumbv7em-none-eabihf/debug/build/defmt-36a2ab5d209daca3/out/defmt.x:7: symbol not found: __defmt_default_panic
          rust-lld: error: /Users/jonathan/Documents/clients/training/open-rust-embedded-2024-10-02/rust-exercises-v1.17.0/nrf52-code/radio-app/target/thumbv7em-none-eabihf/debug/build/defmt-36a2ab5d209daca3/out/defmt.x:7: symbol not found: __defmt_default_panic

That symbol is defined here: https://github.com/knurling-rs/defmt/blob/b7a89f56059fc66ac3c7cc3445d092829599e699/defmt/src/lib.rs#L365

Bisect

@Dirbaio said:

searched nightlies: from nightly-2024-07-30 to nightly-2024-10-02
regressed nightly: nightly-2024-08-01
searched commit range: f8060d2...28a58f2
regressed commit: 0b5eb7b

That's the LLVM 19 upgrade.

Activity

  1. jonathanpallant
    added
    C-bugCategory: This is a bug.
    regression-untriagedUntriaged performance or correctness regression.
    on Oct 2, 2024
  2. rustbot
    added
    I-prioritizeIssue needs a team member to assess the impact. Will be replaced by P-{low,medium,high,critical}
    needs-triageThis issue may need triage. Remove when done. See docs forge.rust-lang.org/release/issue-triaging
    on Oct 2, 2024

  3. Dirbaio commented on Oct 2, 2024

    @Dirbaio
    Dirbaio
    on Oct 2, 2024
    Contributor

    it regressed both with and without --release.

  4. jonathanpallant commented on Oct 2, 2024

    @jonathanpallant
    jonathanpallant
    on Oct 2, 2024
    ContributorAuthor

    I also ran a bisect:

    searched nightlies: from nightly-2024-07-01 to nightly-2024-10-02
    regressed nightly: nightly-2024-08-01
    searched commit range: f8060d2...28a58f2
    regressed commit: 0b5eb7b

  5. saethlin
    added
    A-LLVMArea: Code generation parts specific to LLVM. Both correctness bugs and optimization-related issues.
    and removed
    needs-triageThis issue may need triage. Remove when done. See docs forge.rust-lang.org/release/issue-triaging
    on Oct 2, 2024

  6. apiraino commented on Oct 2, 2024

    @apiraino
    apiraino
    on Oct 2, 2024
    Contributor

    WG-prioritization assigning priority (Zulip discussion).

    I can also reproduce on current beta so tagging accordingly

    @rustbot label -I-prioritize +P-medium +regression-from-stable-to-beta

  7. rustbot
    added
    P-mediumMedium priority
    regression-from-stable-to-betaPerformance or correctness regression from stable to beta.
    and removed
    I-prioritizeIssue needs a team member to assess the impact. Will be replaced by P-{low,medium,high,critical}
    on Oct 2, 2024
  8. nikic
    added
    E-needs-mcveCall for participation: This issue has a repro, but needs a Minimal Complete and Verifiable Example
    on Oct 2, 2024

  9. Dirbaio commented on Oct 2, 2024

    @Dirbaio
    Dirbaio
    on Oct 2, 2024
    Contributor

    minimized, zero deps -> https://github.com/Dirbaio/defmt-repro

    [dirbaio@mars defmt-repro]$ rustc --version
rustc 1.83.0-nightly (06bb8364a 2024-10-01)
[dirbaio@mars defmt-repro]$ cargo build
   Compiling radio_app v0.0.0 (/home/dirbaio/defmt-repro)
error: linking with `rust-lld` failed: exit status: 1
  |
  = note: LC_ALL="C" PATH="/home/dirb(snip)47a" "--gc-sections" "-Tlol.x"
  = note: rust-lld: error: lol.x:1: symbol not found: __defmt_default_panic
          rust-lld: error: lol.x:1: symbol not found: __defmt_default_panic
          rust-lld: error: lol.x:1: symbol not found: __defmt_default_panic

error: could not compile `radio_app` (bin "radio_app") due to 1 previous error
[dirbaio@mars defmt-repro]$ rustc +stable --version
rustc 1.81.0 (eeb90cda1 2024-09-04)
[dirbaio@mars defmt-repro]$ cargo +stable build
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.06s

  10. Dirbaio commented on Oct 2, 2024

    @Dirbaio
    Dirbaio
    on Oct 2, 2024
    Contributor

    maybe related: llvm/llvm-project@ebb326a

  11. 32 remaining items

  12. Urhengulas commented on Oct 16, 2024

    @Urhengulas
    Urhengulas
    on Oct 16, 2024
    Contributor

    Upstream LLVM will not backport the relevant fixes, so I will add a test case.

    Do you think there is a chance that this "bug" will come back to us? We are currently evaluating if we should apply a fix/safeguard in defmt.

  13. dianqk commented on Oct 16, 2024

    @dianqk
    dianqk
    on Oct 16, 2024
    Member

    Upstream LLVM will not backport the relevant fixes, so I will add a test case.

    Do you think there is a chance that this "bug" will come back to us? We are currently evaluating if we should apply a fix/safeguard in defmt.

    No. The main branch of LLVM has fixed. The next major update will include it.

  14. Urhengulas commented on Oct 16, 2024

    @Urhengulas
    Urhengulas
    on Oct 16, 2024
    Contributor

    Upstream LLVM will not backport the relevant fixes, so I will add a test case.

    Do you think there is a chance that this "bug" will come back to us? We are currently evaluating if we should apply a fix/safeguard in defmt.

    No. The main branch of LLVM has fixed. The next major update will include it.

    Perfect!

  15. thejpster commented on Oct 16, 2024

    @thejpster
    thejpster
    on Oct 16, 2024
    Contributor

    Lgtm

  16. apiraino
    closed this as completedon Oct 16, 2024

  17. jannic commented on Oct 16, 2024

    @jannic
    jannic
    on Oct 16, 2024
    Contributor

    Also tried with the stable prerelease from https://internals.rust-lang.org/t/rust-1-82-0-pre-release-testing/21705. Problem is solved.

  18. dianqk
    added a commit that references this issue on Oct 22, 2024

    Add a test case for rust-lang#131164

    ff00622
  19. matthiaskrgr
    added a commit that references this issue on Oct 22, 2024

    Rollup merge of rust-lang#132036 - DianQK:test-131164, r=jieyouxu

    b87c8d6
  20. bors
    added 2 commits that reference this issue on Oct 22, 2024

    Auto merge of rust-lang#132042 - matthiaskrgr:rollup-eloj566, r=matth…

    abf7479

    Auto merge of rust-lang#132036 - DianQK:test-131164, r=<try>

    3e8141c
  21. dianqk
    added a commit that references this issue on Oct 23, 2024

    Add a test case for rust-lang#131164

    6570a6f
  22. fmease
    added 2 commits that reference this issue on Oct 23, 2024

    Rollup merge of rust-lang#132036 - DianQK:test-131164, r=jieyouxu

    2f19d5a

    Rollup merge of rust-lang#132036 - DianQK:test-131164, r=jieyouxu

    f3d4887
  23. bors
    added a commit that references this issue on Oct 23, 2024

    Auto merge of rust-lang#132079 - fmease:rollup-agrd358, r=fmease

    b8bb296
  24. rust-timer
    added a commit that references this issue on Oct 24, 2024

    Unrolled build for rust-lang#132036

    a213132
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Metadata

Metadata

Assignees

No one assigned

    Labels

    A-LLVMArea: Code generation parts specific to LLVM. Both correctness bugs and optimization-related issues.A-linkageArea: linking into static, shared libraries and binariesC-bugCategory: This is a bug.P-highHigh priorityS-has-mcveStatus: A Minimal Complete and Verifiable Example has been found for this issueT-compilerRelevant to the compiler team, which will review and decide on the PR/issue.regression-from-stable-to-betaPerformance or correctness regression from stable to beta.

    Type

    No type

    Projects

    No projects

      Milestone

      Relationships

      None yet

      Development

      No branches or pull requests

      Issue actions