Function with_r_unwind_protect_or_raise 

pub fn with_r_unwind_protect_or_raise<F, R>(f: F, call: Option<SEXP>) -> R
where
    F: FnOnce() -> R,

Execute a closure with R unwind protection, raising any Rust panic as an R error via Rf_eval(stop(structure(...))).

If the closure panics, the panic is caught and converted to an R error (longjmp) with rust_* class layering. If R raises an error (longjmp), all Rust RAII resources are properly dropped before R continues unwinding.

This is NOT the user-facing path for #[miniextendr] functions. That path is with_r_unwind_protect, which returns a tagged SEXP instead of longjmping (the macro-generated R wrapper raises the structured condition).

This raising-variant exists for guard sites that have no R wrapper between them and R’s runtime:

• ALTREP RUnwind guard callbacks (via with_r_unwind_protect_sourced)
• FFI guard tests / benchmarks exercising the raw R_UnwindProtect mechanism

In those contexts there is no consumer-side R wrapper to inspect a tagged SEXP. Panics are routed through raise_rust_condition_via_stop so they still receive rust_* class layering (issue #345). Trait-ABI shims use a separate SEXP-returning variant (with_r_unwind_protect_shim) that re-panics at the View boundary.

Arguments

• f - The closure to execute
• call - Optional R call SEXP for better error messages