From 698f8c2f01ea549d77d7dc3338a12e04c11057b9 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 17 Apr 2024 14:02:58 +0200 Subject: Adding upstream version 1.64.0+dfsg1. Signed-off-by: Daniel Baumann --- library/proc_macro/src/bridge/closure.rs | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) create mode 100644 library/proc_macro/src/bridge/closure.rs (limited to 'library/proc_macro/src/bridge/closure.rs') diff --git a/library/proc_macro/src/bridge/closure.rs b/library/proc_macro/src/bridge/closure.rs new file mode 100644 index 000000000..d371ae3ce --- /dev/null +++ b/library/proc_macro/src/bridge/closure.rs @@ -0,0 +1,32 @@ +//! Closure type (equivalent to `&mut dyn FnMut(A) -> R`) that's `repr(C)`. + +use std::marker::PhantomData; + +#[repr(C)] +pub struct Closure<'a, A, R> { + call: unsafe extern "C" fn(*mut Env, A) -> R, + env: *mut Env, + // Prevent Send and Sync impls. `!Send`/`!Sync` is the usual way of doing + // this, but that requires unstable features. rust-analyzer uses this code + // and avoids unstable features. + // + // The `'a` lifetime parameter represents the lifetime of `Env`. + _marker: PhantomData<*mut &'a mut ()>, +} + +struct Env; + +impl<'a, A, R, F: FnMut(A) -> R> From<&'a mut F> for Closure<'a, A, R> { + fn from(f: &'a mut F) -> Self { + unsafe extern "C" fn call R>(env: *mut Env, arg: A) -> R { + (*(env as *mut _ as *mut F))(arg) + } + Closure { call: call::, env: f as *mut _ as *mut Env, _marker: PhantomData } + } +} + +impl<'a, A, R> Closure<'a, A, R> { + pub fn call(&mut self, arg: A) -> R { + unsafe { (self.call)(self.env, arg) } + } +} -- cgit v1.2.3