The tracing macros such as info!, debug! or trace! from the log crate are not compiled away in release mode, because tracing can be enabled at runtime (via env_logger).
In principle, tracing can be disabled at compile time by enabling some features in the log crate (https://docs.rs/log/0.4.8/log/#compile-time-filters). However, enabling a feature for a crate affects all code that also depend on this crate within a build. So if a binary depends on lzma-rs and wants to log something else, then it cannot optimize away logging in lzma-rs via log's features.
A better solution would be to have a feature in lzma-rs to enable logging (as it is mostly useful for developing lzma-rs). By default, this logging feature will be off so that users of lzma-rs see a performance improvement in general.
The tracing macros such as
info!,debug!ortrace!from the log crate are not compiled away in release mode, because tracing can be enabled at runtime (via env_logger).In principle, tracing can be disabled at compile time by enabling some features in the
logcrate (https://docs.rs/log/0.4.8/log/#compile-time-filters). However, enabling a feature for a crate affects all code that also depend on this crate within a build. So if a binary depends onlzma-rsand wants to log something else, then it cannot optimize away logging inlzma-rsvialog's features.A better solution would be to have a feature in
lzma-rsto enable logging (as it is mostly useful for developinglzma-rs). By default, this logging feature will be off so that users oflzma-rssee a performance improvement in general.