Reorder passes so that AddValidation can run after ElaborateDrops

diff --git a/src/librustc_driver/driver.rs b/src/librustc_driver/driver.rs
index 68e6b0f50d1d6902cfca857b7729ee2036080b20..2b667d83e35e5ed455900fc61e246e355f501cc3 100644 (file)
--- a/src/librustc_driver/driver.rs
+++ b/src/librustc_driver/driver.rs
@@ -925,10 +925,6 @@ macro_rules! try_with_f {
     let mut passes = Passes::new();
     passes.push_hook(mir::transform::dump_mir::DumpMir);
 
-    // Insert AcquireValid and ReleaseValid calls.  Conceptually, this
-    // pass is actually part of MIR building.
-    passes.push_pass(MIR_CONST, mir::transform::add_validation::AddValidation);
-
     // Remove all `EndRegion` statements that are not involved in borrows.
     passes.push_pass(MIR_CONST, mir::transform::clean_end_regions::CleanEndRegions);
 
@@ -937,6 +933,8 @@ macro_rules! try_with_f {
     passes.push_pass(MIR_CONST, mir::transform::type_check::TypeckMir);
     passes.push_pass(MIR_CONST, mir::transform::rustc_peek::SanityCheck);
 
+    // We compute "constant qualifications" betwen MIR_CONST and MIR_VALIDATED.
+
     // What we need to run borrowck etc.
     passes.push_pass(MIR_VALIDATED, mir::transform::qualify_consts::QualifyAndPromoteConstants);
     passes.push_pass(MIR_VALIDATED,
@@ -944,18 +942,23 @@ macro_rules! try_with_f {
     passes.push_pass(MIR_VALIDATED, mir::transform::simplify::SimplifyCfg::new("qualify-consts"));
     passes.push_pass(MIR_VALIDATED, mir::transform::nll::NLL);
 
-    // Optimizations begin.
-    passes.push_pass(MIR_OPTIMIZED, mir::transform::no_landing_pads::NoLandingPads);
-    passes.push_pass(MIR_OPTIMIZED, mir::transform::simplify::SimplifyCfg::new("no-landing-pads"));
+    // borrowck runs between MIR_VALIDATED and MIR_OPTIMIZED.
 
-    // From here on out, regions are gone.
-    passes.push_pass(MIR_OPTIMIZED, mir::transform::erase_regions::EraseRegions);
+    // These next passes must be executed together
+    passes.push_pass(MIR_OPTIMIZED, mir::transform::no_landing_pads::NoLandingPads);
     passes.push_pass(MIR_OPTIMIZED, mir::transform::add_call_guards::AddCallGuards);
     passes.push_pass(MIR_OPTIMIZED, mir::transform::elaborate_drops::ElaborateDrops);
     passes.push_pass(MIR_OPTIMIZED, mir::transform::no_landing_pads::NoLandingPads);
     passes.push_pass(MIR_OPTIMIZED, mir::transform::simplify::SimplifyCfg::new("elaborate-drops"));
-
     // No lifetime analysis based on borrowing can be done from here on out.
+
+    // AddValidation needs to run after ElaborateDrops and before EraseRegions.
+    passes.push_pass(MIR_OPTIMIZED, mir::transform::add_validation::AddValidation);
+
+    // From here on out, regions are gone.
+    passes.push_pass(MIR_OPTIMIZED, mir::transform::erase_regions::EraseRegions);
+
+    // Optimizations begin.
     passes.push_pass(MIR_OPTIMIZED, mir::transform::inline::Inline);
     passes.push_pass(MIR_OPTIMIZED, mir::transform::instcombine::InstCombine);
     passes.push_pass(MIR_OPTIMIZED, mir::transform::deaggregator::Deaggregator);

diff --git a/src/librustc_mir/transform/clean_end_regions.rs b/src/librustc_mir/transform/clean_end_regions.rs
index 1a31bf975307caf47430b8683d6c4fc91be4ace4..d7ec58384a46ed97079ff2c378cc262b5415d30e 100644 (file)
--- a/src/librustc_mir/transform/clean_end_regions.rs
+++ b/src/librustc_mir/transform/clean_end_regions.rs
@@ -31,7 +31,6 @@
 
 struct GatherBorrowedRegions {
     seen_regions: FxHashSet<CodeExtent>,
-    in_validation_statement: bool,
 }
 
 struct DeleteTrivialEndRegions<'a> {
@@ -44,8 +43,7 @@ fn run_pass<'a, 'tcx>(&self,
                           _source: MirSource,
                           mir: &mut Mir<'tcx>) {
         let mut gather = GatherBorrowedRegions {
-            seen_regions: FxHashSet(),
-            in_validation_statement: false
+            seen_regions: FxHashSet()
         };
         gather.visit_mir(mir);
 
@@ -71,22 +69,15 @@ fn visit_statement(&mut self,
                        block: BasicBlock,
                        statement: &Statement<'tcx>,
                        location: Location) {
-        self.in_validation_statement = match statement.kind {
-            StatementKind::Validate(..) => true,
-            _ => false,
-        };
         self.super_statement(block, statement, location);
-        self.in_validation_statement = false;
     }
 
     fn visit_ty(&mut self, ty: &Ty<'tcx>, _: Lookup) {
-        // Gather regions that occur in types inside AcquireValid/ReleaseValid statements
-        if self.in_validation_statement {
-            for re in ty.walk().flat_map(|t| t.regions()) {
-                match *re {
-                    RegionKind::ReScope(ce) => { self.seen_regions.insert(ce); }
-                    _ => {},
-                }
+        // Gather regions that occur in types
+        for re in ty.walk().flat_map(|t| t.regions()) {
+            match *re {
+                RegionKind::ReScope(ce) => { self.seen_regions.insert(ce); }
+                _ => {},
             }
         }
         self.super_ty(ty);