// SPDX-License-Identifier: GPL-2.0 // Copyright (C) 2024 Google LLC. //! Logic for tracepoints. /// Declare the Rust entry point for a tracepoint.////// This macro generates an unsafe function that calls into C, and its safety requirements will be/// whatever the relevant C code requires. To document these safety requirements, you may add/// doc-comments when invoking the macro.#[macro_export]macro_rules! declare_trace {    ($($(#[$attr:meta])* $pub:vis unsafe fn $name:ident($($argname:ident : $argtyp:ty),* $(,)?);)*) => {$(        $( #[$attr] )*        #[inline(always)]        $pub unsafe fn $name($($argname : $argtyp),*) {            #[cfg(CONFIG_TRACEPOINTS)]            {                // SAFETY: It's always okay to query the static key for a tracepoint.                let should_trace = unsafe {                    $crate::macros::paste! {                        $crate::jump_label::static_branch_unlikely!(                            $crate::bindings::[< __tracepoint_ $name >],                            $crate::bindings::tracepoint,                            key                        )                    }                };                 if should_trace {                    $crate::macros::paste! {                        // SAFETY: The caller guarantees that it is okay to call this tracepoint.                        unsafe { $crate::bindings::[< rust_do_trace_ $name >]($($argname),*) };                    }                }            }             #[cfg(not(CONFIG_TRACEPOINTS))]            {                // If tracepoints are disabled, insert a trivial use of each argument                // to avoid unused argument warnings.                $( let _unused = $argname; )*            }        }    )*}} pub use declare_trace;