Expand NLL MIR dumps

compiler/rustc_borrowck/src/lib.rs

@@ -229,7 +229,7 @@ fn do_mir_borrowck<'tcx>(
 
     // Dump MIR results into a file, if that is enabled. This let us
     // write unit-tests, as well as helping with debugging.
-    nll::dump_mir_results(&infcx, body, &regioncx, &opt_closure_req);
+    nll::dump_nll_mir(&infcx, body, &regioncx, &opt_closure_req, &borrow_set);
 
     // We also have a `#[rustc_regions]` annotation that causes us to dump
     // information.

compiler/rustc_borrowck/src/nll.rs

@@ -9,6 +9,7 @@ use polonius_engine::{Algorithm, Output};
 use rustc_data_structures::fx::FxIndexMap;
 use rustc_hir::def_id::LocalDefId;
 use rustc_index::IndexSlice;
+use rustc_middle::mir::pretty::{dump_mir_with_options, PrettyPrintMirOptions};
 use rustc_middle::mir::{
     create_dump_file, dump_enabled, dump_mir, Body, ClosureOutlivesSubject,
     ClosureRegionRequirements, PassWhere, Promoted,
@@ -19,6 +20,7 @@ use rustc_mir_dataflow::impls::MaybeInitializedPlaces;
 use rustc_mir_dataflow::move_paths::MoveData;
 use rustc_mir_dataflow::points::DenseLocationMap;
 use rustc_mir_dataflow::ResultsCursor;
+use rustc_session::config::MirIncludeSpans;
 use rustc_span::symbol::sym;
 
 use crate::borrow_set::BorrowSet;
@@ -208,52 +210,90 @@ pub(crate) fn compute_regions<'cx, 'tcx>(
     }
 }
 
-pub(super) fn dump_mir_results<'tcx>(
+/// `-Zdump-mir=nll` dumps MIR annotated with NLL specific information:
+/// - free regions
+/// - inferred region values
+/// - region liveness
+/// - inference constraints and their causes
+///
+/// As well as graphviz `.dot` visualizations of:
+/// - the region constraints graph
+/// - the region SCC graph
+pub(super) fn dump_nll_mir<'tcx>(
     infcx: &BorrowckInferCtxt<'tcx>,
     body: &Body<'tcx>,
     regioncx: &RegionInferenceContext<'tcx>,
     closure_region_requirements: &Option<ClosureRegionRequirements<'tcx>>,
+    borrow_set: &BorrowSet<'tcx>,
 ) {
-    if !dump_enabled(infcx.tcx, "nll", body.source.def_id()) {
+    let tcx = infcx.tcx;
+    if !dump_enabled(tcx, "nll", body.source.def_id()) {
         return;
     }
 
-    dump_mir(infcx.tcx, false, "nll", &0, body, |pass_where, out| {
-        match pass_where {
-            // Before the CFG, dump out the values for each region variable.
-            PassWhere::BeforeCFG => {
-                regioncx.dump_mir(infcx.tcx, out)?;
-                writeln!(out, "|")?;
-
-                if let Some(closure_region_requirements) = closure_region_requirements {
-                    writeln!(out, "| Free Region Constraints")?;
-                    for_each_region_constraint(
-                        infcx.tcx,
-                        closure_region_requirements,
-                        &mut |msg| writeln!(out, "| {msg}"),
-                    )?;
+    // 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!(
+            infcx.tcx.sess.opts.unstable_opts.mir_include_spans,
+            MirIncludeSpans::On | MirIncludeSpans::Nll
+        ),
+    };
+    dump_mir_with_options(
+        tcx,
+        false,
+        "nll",
+        &0,
+        body,
+        |pass_where, out| {
+            match pass_where {
+                // Before the CFG, dump out the values for each region variable.
+                PassWhere::BeforeCFG => {
+                    regioncx.dump_mir(tcx, out)?;
                     writeln!(out, "|")?;
+
+                    if let Some(closure_region_requirements) = closure_region_requirements {
+                        writeln!(out, "| Free Region Constraints")?;
+                        for_each_region_constraint(tcx, closure_region_requirements, &mut |msg| {
+                            writeln!(out, "| {msg}")
+                        })?;
+                        writeln!(out, "|")?;
+                    }
+
+                    if borrow_set.len() > 0 {
+                        writeln!(out, "| Borrows")?;
+                        for (borrow_idx, borrow_data) in borrow_set.iter_enumerated() {
+                            writeln!(
+                                out,
+                                "| {:?}: issued at {:?} in {:?}",
+                                borrow_idx, borrow_data.reserve_location, borrow_data.region
+                            )?;
+                        }
+                        writeln!(out, "|")?;
+                    }
                 }
-            }
 
-            PassWhere::BeforeLocation(_) => {}
+                PassWhere::BeforeLocation(_) => {}
 
-            PassWhere::AfterTerminator(_) => {}
+                PassWhere::AfterTerminator(_) => {}
 
-            PassWhere::BeforeBlock(_) | PassWhere::AfterLocation(_) | PassWhere::AfterCFG => {}
-        }
-        Ok(())
-    });
+                PassWhere::BeforeBlock(_) | PassWhere::AfterLocation(_) | PassWhere::AfterCFG => {}
+            }
+            Ok(())
+        },
+        options,
+    );
 
-    // Also dump the inference graph constraints as a graphviz file.
+    // Also dump the region constraint graph as a graphviz file.
     let _: io::Result<()> = try {
-        let mut file = create_dump_file(infcx.tcx, "regioncx.all.dot", false, "nll", &0, body)?;
+        let mut file = create_dump_file(tcx, "regioncx.all.dot", false, "nll", &0, body)?;
         regioncx.dump_graphviz_raw_constraints(&mut file)?;
     };
 
-    // Also dump the inference graph constraints as a graphviz file.
+    // Also dump the region constraint SCC graph as a graphviz file.
     let _: io::Result<()> = try {
-        let mut file = create_dump_file(infcx.tcx, "regioncx.scc.dot", false, "nll", &0, body)?;
+        let mut file = create_dump_file(tcx, "regioncx.scc.dot", false, "nll", &0, body)?;
         regioncx.dump_graphviz_scc_constraints(&mut file)?;
     };
 }

compiler/rustc_borrowck/src/region_infer/graphviz.rs

@@ -46,7 +46,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
         dot::render(&RawConstraints { regioncx: self }, &mut w)
     }
 
-    /// Write out the region constraint graph.
+    /// Write out the region constraint SCC graph.
     pub(crate) fn dump_graphviz_scc_constraints(&self, mut w: &mut dyn Write) -> io::Result<()> {
         let mut nodes_per_scc: IndexVec<ConstraintSccIndex, _> =
             self.constraint_sccs.all_sccs().map(|_| Vec::new()).collect();

compiler/rustc_codegen_cranelift/src/base.rs

@@ -44,8 +44,9 @@ pub(crate) fn codegen_fn<'tcx>(
     let _mir_guard = crate::PrintOnPanic(|| {
         let mut buf = Vec::new();
         with_no_trimmed_paths!({
-            rustc_middle::mir::pretty::write_mir_fn(tcx, mir, &mut |_, _| Ok(()), &mut buf)
-                .unwrap();
+            use rustc_middle::mir::pretty;
+            let options = pretty::PrettyPrintMirOptions::from_cli(tcx);
+            pretty::write_mir_fn(tcx, mir, &mut |_, _| Ok(()), &mut buf, options).unwrap();
         });
         String::from_utf8_lossy(&buf).into_owned()
     });

compiler/rustc_interface/src/tests.rs

@@ -12,9 +12,10 @@ use rustc_session::config::{
     CollapseMacroDebuginfo, CoverageLevel, CoverageOptions, DebugInfo, DumpMonoStatsFormat,
     ErrorOutputType, ExternEntry, ExternLocation, Externs, FmtDebug, FunctionReturn,
     InliningThreshold, Input, InstrumentCoverage, InstrumentXRay, LinkSelfContained,
-    LinkerPluginLto, LocationDetail, LtoCli, NextSolverConfig, OomStrategy, Options, OutFileName,
-    OutputType, OutputTypes, PAuthKey, PacRet, Passes, PatchableFunctionEntry, Polonius,
-    ProcMacroExecutionStrategy, Strip, SwitchWithOptPath, SymbolManglingVersion, WasiExecModel,
+    LinkerPluginLto, LocationDetail, LtoCli, MirIncludeSpans, NextSolverConfig, OomStrategy,
+    Options, OutFileName, OutputType, OutputTypes, PAuthKey, PacRet, Passes,
+    PatchableFunctionEntry, Polonius, ProcMacroExecutionStrategy, Strip, SwitchWithOptPath,
+    SymbolManglingVersion, WasiExecModel,
 };
 use rustc_session::lint::Level;
 use rustc_session::search_paths::SearchPath;
@@ -705,7 +706,7 @@ fn test_unstable_options_tracking_hash() {
     untracked!(ls, vec!["all".to_owned()]);
     untracked!(macro_backtrace, true);
     untracked!(meta_stats, true);
-    untracked!(mir_include_spans, true);
+    untracked!(mir_include_spans, MirIncludeSpans::On);
     untracked!(nll_facts, true);
     untracked!(no_analysis, true);
     untracked!(no_leak_check, true);