[RISCV] Code model other than medium does not work with lto

[kxxt]

I tried this code:

// hello.rs
fn main() {
    println!("Hello, world!");
}

// command on riscv64
rustc -C code-model=large -C lto hello.rs
// command on x86_64
rustc --target riscv64gc-unknown-linux-gnu -C code-model=large -C lto hello.rs

I expected to see this happen: code compiles without error

Instead, this happened: failed to load bitcode of module "addr2line-*"

on riscv64, archrv rust:

$ rustc -C code-model=large -C lto hello.rs
warning: linking module flags 'Code Model': IDs have conflicting values in '' and 'hello.8b1675587fc60370-cgu.0'

error: failed to load bitcode of module "addr2line-4a5a0cf02a84c587.addr2line.d0fbcb35ed0a8d23-cgu.0.rcgu.o": 

error: aborting due to 1 previous error; 1 warning emitted

On x86_64, latest stable from rustup:

rustc --target riscv64gc-unknown-linux-gnu -C code-model=large -C lto hello.rs
warning: linking module flags 'Code Model': IDs have conflicting values in '' and 'hello.eea8546ba018bd24-cgu.0'

error: failed to load bitcode of module "addr2line-28336428312034c6.addr2line.134ee917f0cf37e1-cgu.0.rcgu.o": 

error: aborting due to 1 previous error; 1 warning emitted

On x86_64, Nightly:

rustc +nightly --target riscv64gc-unknown-linux-gnu -C code-model=large -C lto hello.rs
warning: linking module flags 'Code Model': IDs have conflicting values: 'i32 3' from , and 'i32 4' from hello.4a3c48060548947b-cgu.0

error: failed to load bitcode of module "addr2line-62ef9fdb0627a182.addr2line.746071221f6a6099-cgu.0.rcgu.o": 

error: aborting due to 1 previous error; 1 warning emitted

Meta

rustc --version --verbose:

rustc 1.85.1 (4eb161250 2025-03-15) (Arch Linux rust 1:1.85.1-1)
binary: rustc
commit-hash: 4eb161250e340c8f48f66e2b929ef4a5bed7c181
commit-date: 2025-03-15
host: riscv64gc-unknown-linux-gnu
release: 1.85.1
LLVM version: 19.1.7

rustc 1.86.0 (05f9846f8 2025-03-31)
binary: rustc
commit-hash: 05f9846f893b09a1be1fc8560e33fc3c815cfecb
commit-date: 2025-03-31
host: x86_64-unknown-linux-gnu
release: 1.86.0
LLVM version: 19.1.7

rustc 1.88.0-nightly (5e17a2a91 2025-04-05)
binary: rustc
commit-hash: 5e17a2a91dd7dbefd8b4a1087c2e42257457deeb
commit-date: 2025-04-05
host: x86_64-unknown-linux-gnu
release: 1.88.0-nightly
LLVM version: 20.1.2

This is specific to RISC-V. The same code works fine for x86_64 and aarch64 target. e.g.

rustc +nightly --target aarch64-unknown-linux-gnu -C code-model=large -C lto hello.rs -C linker=/bin/aarch64-linux-gnu-gcc 

[kxxt]

@rustbot label +O-riscv +A-LTO +A-LLVM +S-has-mcve

[kxxt]

rustc +1.42 --target riscv64gc-unknown-linux-gnu -C code-model=large -C lto hello.rs -C linker=/bin/riscv64-linux-gnu-gcc works. This is a regression.

@rustbot label +regression-from-stable-to-stable

[kxxt]

This regression is first introduced in 1.52.0.

[kxxt]

cargo-bisect-rustc:

********************************************************************************
Regression in nightly-2021-03-15
********************************************************************************

fetching https://static.rust-lang.org/dist/2021-03-14/channel-rust-nightly-git-commit-hash.txt
nightly manifest 2021-03-14: 40 B / 40 B [=============================================================================================================================================================================] 100.00 % 1.29 MB/s converted 2021-03-14 to acca818928654807ed3bc1ce0e97df118f8716c8
fetching https://static.rust-lang.org/dist/2021-03-15/channel-rust-nightly-git-commit-hash.txt
nightly manifest 2021-03-15: 40 B / 40 B [=============================================================================================================================================================================] 100.00 % 1.61 MB/s converted 2021-03-15 to d6eaea1c8860adb5302d2fbaad409e36585ab217
looking for regression commit between 2021-03-14 and 2021-03-15
fetching (via remote github) commits from max(acca818928654807ed3bc1ce0e97df118f8716c8, 2021-03-12) to d6eaea1c8860adb5302d2fbaad409e36585ab217
ending github query because we found starting sha: acca818928654807ed3bc1ce0e97df118f8716c8
get_commits_between returning commits, len: 8
  commit[0] 2021-03-13: Auto merge of #83064 - cjgillot:fhash, r=jackh726
  commit[1] 2021-03-14: Auto merge of #83105 - JohnTitor:rollup-tqpm8pb, r=JohnTitor
  commit[2] 2021-03-14: Auto merge of #83028 - GuillaumeGomez:prevent-js-error-if-no-filter, r=Nemo157
  commit[3] 2021-03-14: Auto merge of #83094 - GuillaumeGomez:crates-js-location, r=Nemo157
  commit[4] 2021-03-14: Auto merge of #83044 - kubo39:set-llvm-code-model, r=nikic
  commit[5] 2021-03-14: Auto merge of #83082 - cjgillot:defkey-ii, r=oli-obk
  commit[6] 2021-03-14: Auto merge of #82399 - petrochenkov:modin2, r=Aaron1011
  commit[7] 2021-03-14: Auto merge of #83062 - JohnTitor:improve-reassign-err, r=davidtwco
ERROR: no CI builds available between acca818928654807ed3bc1ce0e97df118f8716c8 and d6eaea1c8860adb5302d2fbaad409e36585ab217 within last 167 days

So it is probably this one: #83044

[kxxt]

Probably related to https://github.com/rust-lang/rust/blob/master/compiler/rustc_target/src/spec/targets/riscv64gc_unknown_linux_gnu.rs#L18

riscv is among the architectures with target_options.code_model set.