About

This binary demonstrates an error where using LTO with static linking causes a bitcode error.

Structure

The top-level crate is a binary which uses the rational library to demonstrate that the functionality is present.

The rational library is made up of 3 main components:

• The rational_impl library is a cdylib and static library, which provides a few simple APIs.
• The rational_impl_types provides shared types for rational and rational_impl.
• The rational crate builds the rational_impl crate using a build script, and then links to it. It does not depend on rational_impl directly, so it should be an independent library as far as cargo is concerned.

Static linking can be controlled using the link_static feature.

Bug

When lto is enabled for the rational_test_app library alongside the link_static feature, (at least on MacOS), the following error occurs:

error: failed to get bitcode from object file for LTO (could not find requested section)

This can be reproduced by running cargo build --release in this repository. If you use a debug build, or enable dynamic linking in the release build (using cargo build --release --no-default-features), then this bug will not trigger.