compiler/rustc_mir/src/borrow_check/consumers.rs

   1 //! This file provides API for compiler consumers.
   2
   3 use rustc_hir::def_id::LocalDefId;
   4 use rustc_index::vec::IndexVec;
   5 use rustc_infer::infer::TyCtxtInferExt;
   6 use rustc_middle::mir::Body;
   7 use rustc_middle::ty::{self, TyCtxt};
   8
   9 pub use super::{
  10     facts::{AllFacts as PoloniusInput, RustcFacts},
  11     location::{LocationTable, RichLocation},
  12     nll::PoloniusOutput,
  13     BodyWithBorrowckFacts,
  14 };
  15
  16 /// This function computes Polonius facts for the given body. It makes a copy of
  17 /// the body because it needs to regenerate the region identifiers.
  18 ///
  19 /// Note:
  20 /// *   This function will panic if the required body was already stolen. This
  21 ///     can, for example, happen when requesting a body of a `const` function
  22 ///     because they are evaluated during typechecking. The panic can be avoided
  23 ///     by overriding the `mir_borrowck` query. You can find a complete example
  24 ///     that shows how to do this at `src/test/run-make/obtain-borrowck/`.
  25 /// *   This function will also panic if computation of Polonius facts
  26 ///     (`-Zpolonius` flag) is not enabled.
  27 ///
  28 /// *   Polonius is highly unstable, so expect regular changes in its signature or other details.
  29 pub fn get_body_with_borrowck_facts<'tcx>(
  30     tcx: TyCtxt<'tcx>,
  31     def: ty::WithOptConstParam<LocalDefId>,
  32 ) -> BodyWithBorrowckFacts<'tcx> {
  33     let (input_body, promoted) = tcx.mir_promoted(def);
  34     tcx.infer_ctxt().enter(|infcx| {
  35         let input_body: &Body<'_> = &input_body.borrow();
  36         let promoted: &IndexVec<_, _> = &promoted.borrow();
  37         *super::do_mir_borrowck(&infcx, input_body, promoted, true).1.unwrap()
  38     })
  39 }