Module runtime 

The code generated by tracers-macros will at runtime require some functionality, both from within this crate but also from third-party crates like failure. It’s important that the generated code use our version of these crates, and not be required to add some explicit dependency itself. So we’ll re-export those dependencies here Re-export our two dependencies that are actually used by code in user crates generated by tracers! macro. By re-exporting the crate and not just the types, we ensure the correct version will be used and spare the user having to add these dependencies themselves. A deeper discussion around this is ongoing right now at: https://github.com/rust-lang-nursery/api-guidelines/issues/176

The build.rs will set a feature to indicate if tracing is enabled at all. If not then there’s no reason to even include this runtime

Re-exports

pub use tracers_core::failure;

pub use tracers_core::libc;

Traits

ProbeArgNativeType

The other half of ProbeArgNativeTypeInfo, which takes a type parameter and thus adds get_default_value.

ProbeArgType

This trait is defined on any type which is supported as an argument to a probe.

ProbeArgWrapper

This trait, a companion to ProbeArgType, wraps a supported type and on demand converts it to its equivalent C type. For scalar types that are directly supported there is no overhead to this wrapping, but many more complicated types, including Rust string types, need additional logic to produce a NULL-terminated byte array.

Functions

wrap

Helper function to wrap a probe arg in its correspondong wrapper without contorting one’s fingers typing angle brackets