New upstream version 1.56.0~beta.4+dfsg1

[rustc.git] / compiler / rustc_mir / src / borrow_check / consumers.rs

diff --git a/compiler/rustc_mir/src/borrow_check/consumers.rs b/compiler/rustc_mir/src/borrow_check/consumers.rs
new file mode 100644 (file)
index 0000000..f6e4e38
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+++ b/compiler/rustc_mir/src/borrow_check/consumers.rs
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+//! This file provides API for compiler consumers.
+
+use rustc_hir::def_id::LocalDefId;
+use rustc_index::vec::IndexVec;
+use rustc_infer::infer::TyCtxtInferExt;
+use rustc_middle::mir::Body;
+use rustc_middle::ty::{self, TyCtxt};
+
+pub use super::{
+    facts::{AllFacts as PoloniusInput, RustcFacts},
+    location::{LocationTable, RichLocation},
+    nll::PoloniusOutput,
+    BodyWithBorrowckFacts,
+};
+
+/// This function computes Polonius facts for the given body. It makes a copy of
+/// the body because it needs to regenerate the region identifiers.
+///
+/// Note:
+/// *   This function will panic if the required body was already stolen. This
+///     can, for example, happen when requesting a body of a `const` function
+///     because they are evaluated during typechecking. The panic can be avoided
+///     by overriding the `mir_borrowck` query. You can find a complete example
+///     that shows how to do this at `src/test/run-make/obtain-borrowck/`.
+/// *   This function will also panic if computation of Polonius facts
+///     (`-Zpolonius` flag) is not enabled.
+///
+/// *   Polonius is highly unstable, so expect regular changes in its signature or other details.
+pub fn get_body_with_borrowck_facts<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    def: ty::WithOptConstParam<LocalDefId>,
+) -> BodyWithBorrowckFacts<'tcx> {
+    let (input_body, promoted) = tcx.mir_promoted(def);
+    tcx.infer_ctxt().enter(|infcx| {
+        let input_body: &Body<'_> = &input_body.borrow();
+        let promoted: &IndexVec<_, _> = &promoted.borrow();
+        *super::do_mir_borrowck(&infcx, input_body, promoted, true).1.unwrap()
+    })
+}