rustc 1.78.0 segfault on MacOS / M1

I get a segfault when I try to run cargo test on the following code:

# Cargo.toml

[package]

name = "rustc-segfault"
edition = "2021"

// src/lib.rs

#[repr(C, align(8))]
pub struct ConstantReader<T> {
    pub phantom: core::marker::PhantomData<T>,
    pub words: &'static [u64],
}

pub mod test_constants {
  pub static VOID_LIST_CONST: crate::ConstantReader<usize> = {
    pub static WORDS: [u64; 1] = [0];
    crate::ConstantReader {
      phantom: ::std::marker::PhantomData,
      words: &WORDS,
    }
  };
}

#[test]
fn test_constants() {
    let _ = test_constants::VOID_LIST_CONST.words.as_ptr();
}

 % rustc -vV
rustc 1.78.0 (9b00956e5 2024-04-29)
binary: rustc
commit-hash: 9b00956e56009bab2aa15d7bff10916599e3d6d6
commit-date: 2024-04-29
host: aarch64-apple-darwin
release: 1.78.0
LLVM version: 18.1.2

 % cargo test
   Compiling rustc-segfault v0.0.0 (/Users/dwrensha/Desktop/rustc-segfault)
error: could not compile `rustc-segfault` (lib test)

Caused by:
  process didn't exit successfully: `/Users/dwrensha/.rustup/toolchains/stable-aarch64-apple-darwin/bin/rustc --crate-name rustc_segfault --edition=2021 src/lib.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --diagnostic-width=179 --emit=dep-info,link -C embed-bitcode=no -C debuginfo=2 -C split-debuginfo=unpacked --test -C metadata=47a41d92fd841df5 -C extra-filename=-47a41d92fd841df5 --out-dir /Users/dwrensha/Desktop/rustc-segfault/target/debug/deps -C incremental=/Users/dwrensha/Desktop/rustc-segfault/target/debug/incremental -L dependency=/Users/dwrensha/Desktop/rustc-segfault/target/debug/deps` (signal: 11, SIGSEGV: invalid memory reference)

I see the same behavior with the latest nightly rustc. I see no error with rustc 1.77.0 or earlier. It also works fine on Linux, and on an older Intel Macbook.

I also updated to the latest XCode to make sure all parts of my toolchain were up to date. Doing so did not make the segfault go away.

The problem disappears if I turn off incremental compilation by adding this to the Cargo.toml:

[profile.dev]
incremental = false

@nikic

I believe this bisects to LLVM 18 from #120055 cc @nikic

We are hitting an LLVM assertion:

Assertion failed: (N < NumContainedTys && "Element number out of range!"), function getElementType, file DerivedTypes.h, line 343.

Could someone please run cargo -v and then repeat the rustc command with -C save-temps and share the bitcode files?

Could someone please run cargo -v and then repeat the rustc command with -C save-temps and share the bitcode files?

I can reproduce it, and I will try to reduce it.

Upstream issue: llvm/llvm-project#92062
Reduced: https://llvm.godbolt.org/z/a4h1abfKc.

target triple = "arm64"

@p = external global { {}, { ptr } }

define void @foo() {
bb:
  %i1 = load ptr, ptr @p, align 8
  store ptr %i1, ptr null, align 8
  ret void
}

@rustbot

It has already been backported to LLVM 18: llvm/llvm-project#92129.
@rustbot label +llvm-fixed-upstream

Auto merge of rust-lang#125288 - nikic:update-llvm-18.1.6, r=cuviper

Navigation Menu

Repository navigation

rustc 1.78.0 segfault on MacOS / M1 #125053

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

rustc 1.78.0 segfault on MacOS / M1 #125053

Description

Activity

dwrensha commented on May 12, 2024

lqd commented on May 13, 2024

saethlin commented on May 13, 2024

nikic commented on May 14, 2024

dianqk commented on May 14, 2024

dianqk commented on May 14, 2024

dianqk commented on May 16, 2024

Metadata

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

Issue actions