[Bug] aptos move coverage source panics when used on features module in move-stdlib

[Rqnsom]

🐛 Bug

While doing some research at Eiger for the extension of the move-spec-test project, I found a problem in the aptos move coverage command.

To reproduce

Code snippet to reproduce

cd aptos-core/aptos-move/framework/move-stdlib;
aptos move test --coverage;
aptos move coverage source --module features;

Stack trace/error message

$ aptos move coverage source --module features
thread 'main' panicked at third_party/move/tools/move-coverage/src/source_coverage.rs:194:69:
attempt to subtract with overflow
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Expected Behavior

The command shouldn't have crashed; instead, a coverage report for the features module should have been printed out.

System information

• Aptos Core Version

$ move-stdlib git:(main) ✗ aptos -V
aptos 4.0.0

• Rust Version

$ move-stdlib git:(main) ✗ rustc -V
rustc 1.78.0 (9b00956e5 2024-04-29)

• Computer OS

$ move-stdlib git:(main) ✗ uname -moprsv                                                                                                                                                                                                                                                                                                                git:(main↓10|…1
Darwin 23.5.0 Darwin Kernel Version 23.5.0: Wed May  1 20:19:05 PDT 2024; root:xnu-10063.121.3~5/RELEASE_ARM64_T8112 arm64 arm

Additional context

N/A

[rahxephon89]

Thanks for reporting this @Rqnsom. We will fix it soon.

[brmataptos]

FYI: This is due to traces for cross-module inline code being wrongly mapped to corresponding lines in the using module.
Will first fix to disable this from happening, but add a flag to include the inline code coverage info (which will be more expensive to gather).

[wrwg]

We know that coverage for inline functions is broken (#9154, #12919) but not that this crashes the tool. Perhaps for compiler v2, we can finally fix this.