From c75c5176c577b56985ba1e1117d949940710ad0e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Fri, 13 Dec 2024 15:44:39 +0000
Subject: [PATCH] introduce beginnings of polonius MIR dump
This is mostly for test purposes to show the localized constraints until
the MIR debugger is set up.
---
compiler/rustc_borrowck/src/lib.rs | 10 ++
compiler/rustc_borrowck/src/polonius/dump.rs | 101 ++++++++++++++++++
compiler/rustc_borrowck/src/polonius/mod.rs | 2 +
.../rustc_borrowck/src/region_infer/values.rs | 5 +
4 files changed, 118 insertions(+)
create mode 100644 compiler/rustc_borrowck/src/polonius/dump.rs
diff --git a/compiler/rustc_borrowck/src/lib.rs b/compiler/rustc_borrowck/src/lib.rs
index f42945787e1e9..5c8e12a1c69ef 100644
--- a/compiler/rustc_borrowck/src/lib.rs
+++ b/compiler/rustc_borrowck/src/lib.rs
@@ -316,6 +316,16 @@ fn do_mir_borrowck<'tcx>(
mbcx.report_move_errors();
+ // If requested, dump polonius MIR.
+ polonius::dump_polonius_mir(
+ &infcx,
+ body,
+ ®ioncx,
+ &borrow_set,
+ &localized_outlives_constraints,
+ &opt_closure_req,
+ );
+
// For each non-user used mutable variable, check if it's been assigned from
// a user-declared local. If so, then put that local into the used_mut set.
// Note that this set is expected to be small - only upvars from closures
diff --git a/compiler/rustc_borrowck/src/polonius/dump.rs b/compiler/rustc_borrowck/src/polonius/dump.rs
new file mode 100644
index 0000000000000..607e3d92bb1a9
--- /dev/null
+++ b/compiler/rustc_borrowck/src/polonius/dump.rs
@@ -0,0 +1,101 @@
+use std::io;
+
+use rustc_middle::mir::pretty::{PrettyPrintMirOptions, dump_mir_with_options};
+use rustc_middle::mir::{Body, ClosureRegionRequirements, PassWhere};
+use rustc_middle::ty::TyCtxt;
+use rustc_session::config::MirIncludeSpans;
+
+use crate::borrow_set::BorrowSet;
+use crate::polonius::{LocalizedOutlivesConstraint, LocalizedOutlivesConstraintSet};
+use crate::{BorrowckInferCtxt, RegionInferenceContext};
+
+/// `-Zdump-mir=polonius` dumps MIR annotated with NLL and polonius specific information.
+// Note: this currently duplicates most of NLL MIR, with some additions for the localized outlives
+// constraints. This is ok for now as this dump will change in the near future to an HTML file to
+// become more useful.
+pub(crate) fn dump_polonius_mir<'tcx>(
+ infcx: &BorrowckInferCtxt<'tcx>,
+ body: &Body<'tcx>,
+ regioncx: &RegionInferenceContext<'tcx>,
+ borrow_set: &BorrowSet<'tcx>,
+ localized_outlives_constraints: &LocalizedOutlivesConstraintSet,
+ closure_region_requirements: &Option<ClosureRegionRequirements<'tcx>>,
+) {
+ let tcx = infcx.tcx;
+ if !tcx.sess.opts.unstable_opts.polonius.is_next_enabled() {
+ return;
+ }
+
+ // We want the NLL extra comments printed by default in NLL MIR dumps (they were removed in
+ // #112346). Specifying `-Z mir-include-spans` on the CLI still has priority: for example,
+ // they're always disabled in mir-opt tests to make working with blessed dumps easier.
+ let options = PrettyPrintMirOptions {
+ include_extra_comments: matches!(
+ tcx.sess.opts.unstable_opts.mir_include_spans,
+ MirIncludeSpans::On | MirIncludeSpans::Nll
+ ),
+ };
+
+ dump_mir_with_options(
+ tcx,
+ false,
+ "polonius",
+ &0,
+ body,
+ |pass_where, out| {
+ emit_polonius_mir(
+ tcx,
+ regioncx,
+ closure_region_requirements,
+ borrow_set,
+ localized_outlives_constraints,
+ pass_where,
+ out,
+ )
+ },
+ options,
+ );
+}
+
+/// Produces the actual NLL + Polonius MIR sections to emit during the dumping process.
+fn emit_polonius_mir<'tcx>(
+ tcx: TyCtxt<'tcx>,
+ regioncx: &RegionInferenceContext<'tcx>,
+ closure_region_requirements: &Option<ClosureRegionRequirements<'tcx>>,
+ borrow_set: &BorrowSet<'tcx>,
+ localized_outlives_constraints: &LocalizedOutlivesConstraintSet,
+ pass_where: PassWhere,
+ out: &mut dyn io::Write,
+) -> io::Result<()> {
+ // Emit the regular NLL front-matter
+ crate::nll::emit_nll_mir(
+ tcx,
+ regioncx,
+ closure_region_requirements,
+ borrow_set,
+ pass_where.clone(),
+ out,
+ )?;
+
+ let liveness = regioncx.liveness_constraints();
+
+ // Add localized outlives constraints
+ match pass_where {
+ PassWhere::BeforeCFG => {
+ if localized_outlives_constraints.outlives.len() > 0 {
+ writeln!(out, "| Localized constraints")?;
+
+ for constraint in &localized_outlives_constraints.outlives {
+ let LocalizedOutlivesConstraint { source, from, target, to } = constraint;
+ let from = liveness.location_from_point(*from);
+ let to = liveness.location_from_point(*to);
+ writeln!(out, "| {source:?} at {from:?} -> {target:?} at {to:?}")?;
+ }
+ writeln!(out, "|")?;
+ }
+ }
+ _ => {}
+ }
+
+ Ok(())
+}
diff --git a/compiler/rustc_borrowck/src/polonius/mod.rs b/compiler/rustc_borrowck/src/polonius/mod.rs
index 03db7ba50edad..fa7e08d9db345 100644
--- a/compiler/rustc_borrowck/src/polonius/mod.rs
+++ b/compiler/rustc_borrowck/src/polonius/mod.rs
@@ -35,6 +35,8 @@
mod constraints;
pub(crate) use constraints::*;
+mod dump;
+pub(crate) use dump::dump_polonius_mir;
pub(crate) mod legacy;
use rustc_middle::mir::{Body, Location};
diff --git a/compiler/rustc_borrowck/src/region_infer/values.rs b/compiler/rustc_borrowck/src/region_infer/values.rs
index a16bce63839b0..0b0757f16ab25 100644
--- a/compiler/rustc_borrowck/src/region_infer/values.rs
+++ b/compiler/rustc_borrowck/src/region_infer/values.rs
@@ -199,6 +199,11 @@ impl LivenessValues {
self.elements.point_from_location(location)
}
+ #[inline]
+ pub(crate) fn location_from_point(&self, point: PointIndex) -> Location {
+ self.elements.to_location(point)
+ }
+
/// When using `-Zpolonius=next`, returns whether the `loan_idx` is live at the given `point`.
pub(crate) fn is_loan_live_at(&self, loan_idx: BorrowIndex, point: PointIndex) -> bool {
self.loans