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use super::{GlobalCtxt, TyCtxt};
use crate::dep_graph::TaskDepsRef;
use crate::ty::query;
use rustc_data_structures::sync::{self, Lock};
use rustc_errors::Diagnostic;
#[cfg(not(parallel_compiler))]
use std::cell::Cell;
use std::mem;
use std::ptr;
use thin_vec::ThinVec;
#[derive(Clone)]
pub struct ImplicitCtxt<'a, 'tcx> {
pub tcx: TyCtxt<'tcx>,
pub query: Option<query::QueryJobId>,
pub diagnostics: Option<&'a Lock<ThinVec<Diagnostic>>>,
pub query_depth: usize,
pub task_deps: TaskDepsRef<'a>,
}
impl<'a, 'tcx> ImplicitCtxt<'a, 'tcx> {
pub fn new(gcx: &'tcx GlobalCtxt<'tcx>) -> Self {
let tcx = TyCtxt { gcx };
ImplicitCtxt {
tcx,
query: None,
diagnostics: None,
query_depth: 0,
task_deps: TaskDepsRef::Ignore,
}
}
}
#[cfg(parallel_compiler)]
use rayon_core::tlv::TLV;
#[cfg(not(parallel_compiler))]
thread_local! {
static TLV: Cell<*const ()> = const { Cell::new(ptr::null()) };
}
#[inline]
fn erase(context: &ImplicitCtxt<'_, '_>) -> *const () {
context as *const _ as *const ()
}
#[inline]
unsafe fn downcast<'a, 'tcx>(context: *const ()) -> &'a ImplicitCtxt<'a, 'tcx> {
&*(context as *const ImplicitCtxt<'a, 'tcx>)
}
#[inline]
pub fn enter_context<'a, 'tcx, F, R>(context: &ImplicitCtxt<'a, 'tcx>, f: F) -> R
where
F: FnOnce() -> R,
{
TLV.with(|tlv| {
let old = tlv.replace(erase(context));
let _reset = rustc_data_structures::OnDrop(move || tlv.set(old));
f()
})
}
#[inline]
pub fn with_context_opt<F, R>(f: F) -> R
where
F: for<'a, 'tcx> FnOnce(Option<&ImplicitCtxt<'a, 'tcx>>) -> R,
{
let context = TLV.get();
if context.is_null() {
f(None)
} else {
sync::assert_sync::<ImplicitCtxt<'_, '_>>();
unsafe { f(Some(downcast(context))) }
}
}
#[inline]
pub fn with_context<F, R>(f: F) -> R
where
F: for<'a, 'tcx> FnOnce(&ImplicitCtxt<'a, 'tcx>) -> R,
{
with_context_opt(|opt_context| f(opt_context.expect("no ImplicitCtxt stored in tls")))
}
#[inline]
pub fn with_related_context<'tcx, F, R>(tcx: TyCtxt<'tcx>, f: F) -> R
where
F: FnOnce(&ImplicitCtxt<'_, 'tcx>) -> R,
{
with_context(|context| {
assert!(ptr::eq(
context.tcx.gcx as *const _ as *const (),
tcx.gcx as *const _ as *const ()
));
let context: &ImplicitCtxt<'_, '_> = unsafe { mem::transmute(context) };
f(context)
})
}
#[inline]
pub fn with<F, R>(f: F) -> R
where
F: for<'tcx> FnOnce(TyCtxt<'tcx>) -> R,
{
with_context(|context| f(context.tcx))
}
#[inline]
pub fn with_opt<F, R>(f: F) -> R
where
F: for<'tcx> FnOnce(Option<TyCtxt<'tcx>>) -> R,
{
with_context_opt(|opt_context| f(opt_context.map(|context| context.tcx)))
}