| //! "Hooks" provide a way for `tcx` functionality to be provided by some downstream crate without |
| //! everything in rustc having to depend on that crate. This is somewhat similar to queries, but |
| //! queries come with a lot of machinery for caching and incremental compilation, whereas hooks are |
| //! just plain function pointers without any of the query magic. |
| |
| use crate::mir; |
| use crate::query::TyCtxtAt; |
| use crate::ty::{Ty, TyCtxt}; |
| use rustc_span::DUMMY_SP; |
| |
| macro_rules! declare_hooks { |
| ($($(#[$attr:meta])*hook $name:ident($($arg:ident: $K:ty),*) -> $V:ty;)*) => { |
| |
| impl<'tcx> TyCtxt<'tcx> { |
| $( |
| $(#[$attr])* |
| #[inline(always)] |
| #[must_use] |
| pub fn $name(self, $($arg: $K,)*) -> $V |
| { |
| self.at(DUMMY_SP).$name($($arg,)*) |
| } |
| )* |
| } |
| |
| impl<'tcx> TyCtxtAt<'tcx> { |
| $( |
| $(#[$attr])* |
| #[inline(always)] |
| #[must_use] |
| #[instrument(level = "debug", skip(self), ret)] |
| pub fn $name(self, $($arg: $K,)*) -> $V |
| { |
| (self.tcx.hooks.$name)(self, $($arg,)*) |
| } |
| )* |
| } |
| |
| pub struct Providers { |
| $(pub $name: for<'tcx> fn( |
| TyCtxtAt<'tcx>, |
| $($arg: $K,)* |
| ) -> $V,)* |
| } |
| |
| impl Default for Providers { |
| fn default() -> Self { |
| Providers { |
| $($name: |_, $($arg,)*| bug!( |
| "`tcx.{}{:?}` cannot be called as `{}` was never assigned to a provider function.\n", |
| stringify!($name), |
| ($($arg,)*), |
| stringify!($name), |
| ),)* |
| } |
| } |
| } |
| |
| impl Copy for Providers {} |
| impl Clone for Providers { |
| fn clone(&self) -> Self { *self } |
| } |
| }; |
| } |
| |
| declare_hooks! { |
| /// Tries to destructure an `mir::Const` ADT or array into its variant index |
| /// and its field values. This should only be used for pretty printing. |
| hook try_destructure_mir_constant_for_user_output(val: mir::ConstValue<'tcx>, ty: Ty<'tcx>) -> Option<mir::DestructuredConstant<'tcx>>; |
| |
| /// Getting a &core::panic::Location referring to a span. |
| hook const_caller_location(file: rustc_span::Symbol, line: u32, col: u32) -> mir::ConstValue<'tcx>; |
| } |