Make borrowck use polonius output

src/Cargo.lock

@@ -557,6 +557,11 @@ dependencies = [
  "winapi 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "datafrog"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "debug_unreachable"
 version = "0.1.1"
@@ -1450,8 +1455,12 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "polonius-engine"
-version = "0.1.1"
+version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "datafrog 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rustc-hash 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
 
 [[package]]
 name = "precomputed-hash"
@@ -1775,7 +1784,7 @@ dependencies = [
  "jobserver 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "polonius-engine 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "polonius-engine 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "proc_macro 0.0.0",
  "rustc_apfloat 0.0.0",
  "rustc_data_structures 0.0.0",
@@ -2159,10 +2168,11 @@ dependencies = [
  "arena 0.0.0",
  "bitflags 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "byteorder 1.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "either 1.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "graphviz 0.0.0",
  "log 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "log_settings 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "polonius-engine 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "polonius-engine 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc 0.0.0",
  "rustc_apfloat 0.0.0",
  "rustc_data_structures 0.0.0",
@@ -3069,6 +3079,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum crypto-hash 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "09de9ee0fc255ace04c7fa0763c9395a945c37c8292bb554f8d48361d1dcf1b4"
 "checksum curl 0.4.12 (registry+https://github.com/rust-lang/crates.io-index)" = "aaf20bbe084f285f215eef2165feed70d6b75ba29cad24469badb853a4a287d0"
 "checksum curl-sys 0.4.5 (registry+https://github.com/rust-lang/crates.io-index)" = "71c63a540a9ee4e15e56c3ed9b11a2f121239b9f6d7b7fe30f616e048148df9a"
+"checksum datafrog 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "16d724bf4ffe77cdceeecd461009b5f8d9e23c5d645d68bedb4586bf43e7e142"
 "checksum debug_unreachable 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "9a032eac705ca39214d169f83e3d3da290af06d8d1d344d1baad2fd002dca4b3"
 "checksum derive-new 0.5.4 (registry+https://github.com/rust-lang/crates.io-index)" = "ceed73957c449214f8440eec8ad7fa282b67dc9eacbb24a3085b15d60397a17a"
 "checksum diff 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)" = "3c2b69f912779fbb121ceb775d74d51e915af17aaebc38d28a592843a2dd0a3a"
@@ -3162,7 +3173,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum phf_generator 0.7.21 (registry+https://github.com/rust-lang/crates.io-index)" = "6b07ffcc532ccc85e3afc45865469bf5d9e4ef5bfcf9622e3cfe80c2d275ec03"
 "checksum phf_shared 0.7.21 (registry+https://github.com/rust-lang/crates.io-index)" = "07e24b0ca9643bdecd0632f2b3da6b1b89bbb0030e0b992afc1113b23a7bc2f2"
 "checksum pkg-config 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)" = "3a8b4c6b8165cd1a1cd4b9b120978131389f64bdaf456435caa41e630edba903"
-"checksum polonius-engine 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "6201ffe79e3da53bd065fbec2a9b391e5a0dc21038b39bb300612ddc658eb7ee"
+"checksum polonius-engine 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "9385a6d8f8ff6fd7e48a803c6a77fb89cc929dc7e2af6bf972494bbc8ff8b9e4"
 "checksum precomputed-hash 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "925383efa346730478fb4838dbe9137d2a47675ad789c546d150a6e1dd4ab31c"
 "checksum pretty_assertions 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "3a029430f0d744bc3d15dd474d591bed2402b645d024583082b9f63bb936dac6"
 "checksum proc-macro2 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)" = "49b6a521dc81b643e9a51e0d1cf05df46d5a2f3c0280ea72bcb68276ba64a118"

src/librustc/Cargo.toml

@@ -16,7 +16,7 @@ graphviz = { path = "../libgraphviz" }
 jobserver = "0.1"
 lazy_static = "1.0.0"
 log = { version = "0.4", features = ["release_max_level_info", "std"] }
-polonius-engine = "0.1.1"
+polonius-engine = "0.4.0"
 proc_macro = { path = "../libproc_macro" }
 rustc_apfloat = { path = "../librustc_apfloat" }
 rustc_target = { path = "../librustc_target" }

src/librustc/session/config.rs

@@ -1296,6 +1296,8 @@ options! {DebuggingOptions, DebuggingSetter, basic_debugging_options,
                        "dump facts from NLL analysis into side files"),
     disable_nll_user_type_assert: bool = (false, parse_bool, [UNTRACKED],
         "disable user provided type assertion in NLL"),
+    polonius: bool = (false, parse_bool, [UNTRACKED],
+        "enable polonius-based borrow-checker"),
     codegen_time_graph: bool = (false, parse_bool, [UNTRACKED],
         "generate a graphical HTML report of time spent in codegen and LLVM"),
     thinlto: Option<bool> = (None, parse_opt_bool, [TRACKED],

src/librustc_mir/Cargo.toml

@@ -11,10 +11,11 @@ crate-type = ["dylib"]
 [dependencies]
 arena = { path = "../libarena" }
 bitflags = "1.0"
+either = "1.5.0"
 graphviz = { path = "../libgraphviz" }
 log = "0.4"
 log_settings = "0.1.1"
-polonius-engine = "0.1.1"
+polonius-engine = "0.4.0"
 rustc = { path = "../librustc" }
 rustc_target = { path = "../librustc_target" }
 rustc_data_structures = { path = "../librustc_data_structures" }

src/librustc_mir/borrow_check/flows.rs

@@ -14,15 +14,22 @@
 //! but is not as ugly as it is right now.
 
 use rustc::mir::{BasicBlock, Location};
+use rustc::ty::RegionVid;
 use rustc_data_structures::indexed_set::Iter;
 
-use dataflow::{MaybeInitializedPlaces, MaybeUninitializedPlaces};
+use borrow_check::location::LocationIndex;
+
+use polonius_engine::Output;
+
+use dataflow::move_paths::indexes::BorrowIndex;
+use dataflow::move_paths::HasMoveData;
+use dataflow::Borrows;
 use dataflow::{EverInitializedPlaces, MovingOutStatements};
-use dataflow::{Borrows};
 use dataflow::{FlowAtLocation, FlowsAtLocation};
-use dataflow::move_paths::HasMoveData;
-use dataflow::move_paths::indexes::BorrowIndex;
+use dataflow::{MaybeInitializedPlaces, MaybeUninitializedPlaces};
+use either::Either;
 use std::fmt;
+use std::rc::Rc;
 
 // (forced to be `pub` due to its use as an associated type below.)
 crate struct Flows<'b, 'gcx: 'tcx, 'tcx: 'b> {
@@ -31,6 +38,9 @@ crate struct Flows<'b, 'gcx: 'tcx, 'tcx: 'b> {
     pub uninits: FlowAtLocation<MaybeUninitializedPlaces<'b, 'gcx, 'tcx>>,
     pub move_outs: FlowAtLocation<MovingOutStatements<'b, 'gcx, 'tcx>>,
     pub ever_inits: FlowAtLocation<EverInitializedPlaces<'b, 'gcx, 'tcx>>,
+
+    /// Polonius Output
+    pub polonius_output: Option<Rc<Output<RegionVid, BorrowIndex, LocationIndex>>>,
 }
 
 impl<'b, 'gcx, 'tcx> Flows<'b, 'gcx, 'tcx> {
@@ -40,18 +50,27 @@ impl<'b, 'gcx, 'tcx> Flows<'b, 'gcx, 'tcx> {
         uninits: FlowAtLocation<MaybeUninitializedPlaces<'b, 'gcx, 'tcx>>,
         move_outs: FlowAtLocation<MovingOutStatements<'b, 'gcx, 'tcx>>,
         ever_inits: FlowAtLocation<EverInitializedPlaces<'b, 'gcx, 'tcx>>,
+        polonius_output: Option<Rc<Output<RegionVid, BorrowIndex, LocationIndex>>>,
     ) -> Self {
         Flows {
             borrows,
             inits,
             uninits,
             move_outs,
             ever_inits,
+            polonius_output,
         }
     }
 
-    crate fn borrows_in_scope(&self) -> impl Iterator<Item = BorrowIndex> + '_ {
-        self.borrows.iter_incoming()
+    crate fn borrows_in_scope(
+        &self,
+        location: LocationIndex,
+    ) -> impl Iterator<Item = BorrowIndex> + '_ {
+        if let Some(ref polonius) = self.polonius_output {
+            Either::Left(polonius.errors_at(location).iter().cloned())
+        } else {
+            Either::Right(self.borrows.iter_incoming())
+        }
     }
 
     crate fn with_outgoing_borrows(&self, op: impl FnOnce(Iter<BorrowIndex>)) {
@@ -66,7 +85,7 @@ macro_rules! each_flow {
         FlowAtLocation::$meth(&mut $this.uninits, $arg);
         FlowAtLocation::$meth(&mut $this.move_outs, $arg);
         FlowAtLocation::$meth(&mut $this.ever_inits, $arg);
-    }
+    };
 }
 
 impl<'b, 'gcx, 'tcx> FlowsAtLocation for Flows<'b, 'gcx, 'tcx> {
@@ -134,8 +153,7 @@ impl<'b, 'gcx, 'tcx> fmt::Display for Flows<'b, 'gcx, 'tcx> {
                 s.push_str(", ");
             };
             saw_one = true;
-            let move_path =
-                &self.uninits.operator().move_data().move_paths[mpi_uninit];
+            let move_path = &self.uninits.operator().move_data().move_paths[mpi_uninit];
             s.push_str(&format!("{}", move_path));
         });
         s.push_str("] ");
@@ -159,8 +177,7 @@ impl<'b, 'gcx, 'tcx> fmt::Display for Flows<'b, 'gcx, 'tcx> {
                 s.push_str(", ");
             };
             saw_one = true;
-            let ever_init =
-                &self.ever_inits.operator().move_data().inits[mpi_ever_init];
+            let ever_init = &self.ever_inits.operator().move_data().inits[mpi_ever_init];
             s.push_str(&format!("{:?}", ever_init));
         });
         s.push_str("]");

src/librustc_mir/borrow_check/mod.rs

@@ -198,7 +198,7 @@ fn do_mir_borrowck<'a, 'gcx, 'tcx>(
     let borrow_set = Rc::new(BorrowSet::build(tcx, mir));
 
     // If we are in non-lexical mode, compute the non-lexical lifetimes.
-    let (regioncx, opt_closure_req) = nll::compute_regions(
+    let (regioncx, polonius_output, opt_closure_req) = nll::compute_regions(
         infcx,
         def_id,
         free_regions,
@@ -259,6 +259,7 @@ fn do_mir_borrowck<'a, 'gcx, 'tcx>(
         flow_uninits,
         flow_move_outs,
         flow_ever_inits,
+        polonius_output,
     );
 
     mbcx.analyze_results(&mut state); // entry point for DataflowResultsConsumer
@@ -936,6 +937,8 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
         let mut error_reported = false;
         let tcx = self.tcx;
         let mir = self.mir;
+        let location_table = &LocationTable::new(mir);
+        let location = location_table.start_index(context.loc);
         let borrow_set = self.borrow_set.clone();
         each_borrow_involving_path(
             self,
@@ -944,7 +947,7 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
             context,
             (sd, place_span.0),
             &borrow_set,
-            flow_state.borrows_in_scope(),
+            flow_state.borrows_in_scope(location),
             |this, borrow_index, borrow|
             match (rw, borrow.kind) {
                 // Obviously an activation is compatible with its own