Skip to content

Сompiler can't remove panic locations if they are not used in panic handler #129330

Closed
@StackOverflowExcept1on

Description

Code

Code is minimized as much as possible and here is a demo repository: https://github.com/StackOverflowExcept1on/rust-regression

  • program - this is smart contract that panics and terminates with an error
  • project - some intermediate directory that is generated by our utility
git clone https://github.com/StackOverflowExcept1on/rust-regression.git
cd rust-regression/project
./check.sh
/home/user/rust-regression/project
   Compiling rustversion v1.0.17
   Compiling arrayvec v0.7.6
   Compiling wasm-program v0.1.0 (/home/user/rust-regression/wasm-program)
   Compiling wasm-project v0.1.0 (/home/user/rust-regression/wasm-project)
    Finished `release` profile [optimized] target(s) in 0.59s
grep: ./target/wasm32-unknown-unknown/release/wasm_program.wasm: binary file matches
/home/user/... found in WASM :(

I expected to see this happen: /home/user/... removed from wasm

Instead, this happened: /home/user/... is not removed from wasm

We want /home/user/... to always be removed from smart contracts, otherwise it reveals some information about creator name and also increases cost of uploading to blockchain. We tried using --remap-path-prefix, but it results in longer build times. On the old version, rustc compiler was so smart that it figured out how to remove all panic locations from the binary file.

Maybe related to #115974, but I haven't checked every commit. Although it is worth noting that #115974 is very useful as we can get panic message and remove panic location in stable rust.

Version it worked on

It most recently worked on: nightly-2024-06-12

$ rustc +nightly-2024-06-12 --version --verbose
rustc 1.81.0-nightly (d0227c6a1 2024-06-11)
binary: rustc
commit-hash: d0227c6a19c2d6e8dceb87c7a2776dc2b10d2a04
commit-date: 2024-06-11
host: x86_64-unknown-linux-gnu
release: 1.81.0-nightly
LLVM version: 18.1.7

Version with regression

Starting from nightly-2024-06-13, behavior has changed

$ rustc +nightly-2024-06-13 --version --verbose
rustc 1.81.0-nightly (8337ba918 2024-06-12)
binary: rustc
commit-hash: 8337ba9189de188e2ed417018af2bf17a57d51ac
commit-date: 2024-06-12
host: x86_64-unknown-linux-gnu
release: 1.81.0-nightly
LLVM version: 18.1.7

Activity

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

Metadata

Assignees

No one assigned

    Labels

    A-panicArea: Panicking machineryC-optimizationCategory: An issue highlighting optimization opportunities or PRs implementing suchregression-from-stable-to-stablePerformance or correctness regression from one stable version to another.

    Type

    No type

    Projects

    No projects

    Milestone

    No milestone

    Relationships

    None yet

    Development

    No branches or pull requests

    Issue actions