tls_model
The tracking issue for this feature is: None.
Option -Z tls-model controls TLS model used to
generate code for accessing #[thread_local] static items.
Supported values for this option are:
global-dynamic- General Dynamic TLS Model (alternatively called Global Dynamic) is the most general option usable in all circumstances, even if the TLS data is defined in a shared library loaded at runtime and is accessed from code outside of that library.
This is the default for most targets.local-dynamic- model usable if the TLS data is only accessed from the shared library or executable it is defined in. The TLS data may be in a library loaded after startup (viadlopen).initial-exec- model usable if the TLS data is defined in the executable or in a shared library loaded at program startup. The TLS data must not be in a library loaded after startup (viadlopen).local-exec- model usable only if the TLS data is defined directly in the executable, but not in a shared library, and is accessed only from that executable.
rustc and LLVM may use a more optimized model than specified if they know that we are producing
an executable rather than a library, or that the static item is private enough.