Unconditionally run RevealAll pass and run it earlier

Author: oli-obk

compiler/rustc_mir_transform/src/lib.rs

@@ -480,6 +480,7 @@ fn run_runtime_lowering_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
     let passes: &[&dyn MirPass<'tcx>] = &[
         // These next passes must be executed together
         &add_call_guards::CriticalCallEdges,
+        &reveal_all::RevealAll, // has to be done before drop elaboration, since we need to drop opaque types, too.
         &elaborate_drops::ElaborateDrops,
         // This will remove extraneous landing pads which are no longer
         // necessary as well as well as forcing any call in a non-unwinding
@@ -526,7 +527,6 @@ fn run_optimization_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
         body,
         &[
             &check_alignment::CheckAlignment,
-            &reveal_all::RevealAll, // has to be done before inlining, since inlined code is in RevealAll mode.
             &lower_slice_len::LowerSliceLenCalls, // has to be done before inlining, otherwise actual call will be almost always inlined. Also simple, so can just do first
             &unreachable_prop::UnreachablePropagation,
             &uninhabited_enum_branching::UninhabitedEnumBranching,

compiler/rustc_mir_transform/src/reveal_all.rs

@@ -8,10 +8,6 @@ use rustc_middle::ty::{self, Ty, TyCtxt};
 pub struct RevealAll;
 
 impl<'tcx> MirPass<'tcx> for RevealAll {
-    fn is_enabled(&self, sess: &rustc_session::Session) -> bool {
-        sess.mir_opt_level() >= 3 || super::inline::Inline.is_enabled(sess)
-    }
-
     fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
         // Do not apply this transformation to generators.
         if body.generator.is_some() {

tests/incremental/hashes/function_interfaces.rs

@@ -302,7 +302,7 @@ pub fn return_impl_trait() -> i32        {
 }
 
 #[cfg(not(any(cfail1,cfail4)))]
-#[rustc_clean(cfg = "cfail2", except = "hir_owner, hir_owner_nodes, typeck, fn_sig, optimized_mir")]
+#[rustc_clean(cfg = "cfail2", except = "hir_owner, hir_owner_nodes, typeck, fn_sig")]
 #[rustc_clean(cfg = "cfail3")]
 #[rustc_clean(cfg = "cfail5", except = "hir_owner, hir_owner_nodes, typeck, fn_sig, optimized_mir")]
 #[rustc_clean(cfg = "cfail6")]

tests/mir-opt/inline/issue_78442.bar.RevealAll.panic-abort.diff

@@ -15,28 +15,44 @@
           StorageLive(_2);
           StorageLive(_3);
           StorageLive(_4);
-          _4 = hide_foo() -> [return: bb1, unwind unreachable];
+          _4 = hide_foo() -> [return: bb1, unwind: bb6];
       }
 
       bb1: {
           _3 = &_4;
           StorageLive(_5);
           _5 = ();
--         _2 = <impl Fn() as Fn<()>>::call(move _3, move _5) -> [return: bb2, unwind unreachable];
-+         _2 = <fn() {foo} as Fn<()>>::call(move _3, move _5) -> [return: bb2, unwind unreachable];
+-         _2 = <impl Fn() as Fn<()>>::call(move _3, move _5) -> [return: bb2, unwind: bb5];
++         _2 = <fn() {foo} as Fn<()>>::call(move _3, move _5) -> [return: bb2, unwind: bb5];
       }
 
       bb2: {
           StorageDead(_5);
           StorageDead(_3);
+          drop(_4) -> [return: bb3, unwind: bb6];
+      }
+  
+      bb3: {
           StorageDead(_4);
           StorageDead(_2);
           _0 = const ();
-          drop(_1) -> [return: bb3, unwind unreachable];
+          drop(_1) -> [return: bb4, unwind: bb7];
       }
 
-      bb3: {
+      bb4: {
           return;
       }
+  
+      bb5 (cleanup): {
+          drop(_4) -> [return: bb6, unwind terminate(cleanup)];
+      }
+  
+      bb6 (cleanup): {
+          drop(_1) -> [return: bb7, unwind terminate(cleanup)];
+      }
+  
+      bb7 (cleanup): {
+          resume;
+      }
   }
 

tests/mir-opt/inline/issue_78442.bar.RevealAll.panic-unwind.diff

@@ -15,35 +15,43 @@
           StorageLive(_2);
           StorageLive(_3);
           StorageLive(_4);
-          _4 = hide_foo() -> [return: bb1, unwind: bb4];
+          _4 = hide_foo() -> [return: bb1, unwind: bb6];
       }
 
       bb1: {
           _3 = &_4;
           StorageLive(_5);
           _5 = ();
--         _2 = <impl Fn() as Fn<()>>::call(move _3, move _5) -> [return: bb2, unwind: bb4];
-+         _2 = <fn() {foo} as Fn<()>>::call(move _3, move _5) -> [return: bb2, unwind: bb4];
+-         _2 = <impl Fn() as Fn<()>>::call(move _3, move _5) -> [return: bb2, unwind: bb5];
++         _2 = <fn() {foo} as Fn<()>>::call(move _3, move _5) -> [return: bb2, unwind: bb5];
       }
 
       bb2: {
           StorageDead(_5);
           StorageDead(_3);
+          drop(_4) -> [return: bb3, unwind: bb6];
+      }
+  
+      bb3: {
           StorageDead(_4);
           StorageDead(_2);
           _0 = const ();
-          drop(_1) -> [return: bb3, unwind: bb5];
+          drop(_1) -> [return: bb4, unwind continue];
       }
 
-      bb3: {
+      bb4: {
           return;
       }
 
-      bb4 (cleanup): {
-          drop(_1) -> [return: bb5, unwind terminate(cleanup)];
+      bb5 (cleanup): {
+          drop(_4) -> [return: bb6, unwind terminate(cleanup)];
       }
 
-      bb5 (cleanup): {
+      bb6 (cleanup): {
+          drop(_1) -> [return: bb7, unwind terminate(cleanup)];
+      }
+  
+      bb7 (cleanup): {
           resume;
       }
   }

tests/ui/polymorphization/generators.rs

@@ -32,6 +32,7 @@ where
 
 #[rustc_polymorphize_error]
 pub fn unused_type<T>() -> impl Generator<(), Yield = u32, Return = u32> + Unpin {
+    //~^ ERROR item has unused generic parameters
     || {
         //~^ ERROR item has unused generic parameters
         yield 1;
@@ -57,6 +58,7 @@ pub fn used_type_in_return<R: Default>() -> impl Generator<(), Yield = u32, Retu
 
 #[rustc_polymorphize_error]
 pub fn unused_const<const T: u32>() -> impl Generator<(), Yield = u32, Return = u32> + Unpin {
+    //~^ ERROR item has unused generic parameters
     || {
         //~^ ERROR item has unused generic parameters
         yield 1;

tests/ui/polymorphization/generators.stderr

@@ -8,20 +8,34 @@ LL | #![feature(generic_const_exprs, generators, generator_trait, rustc_attrs)]
    = note: `#[warn(incomplete_features)]` on by default
 
 error: item has unused generic parameters
-  --> $DIR/generators.rs:35:5
+  --> $DIR/generators.rs:36:5
    |
 LL | pub fn unused_type<T>() -> impl Generator<(), Yield = u32, Return = u32> + Unpin {
    |                    - generic parameter `T` is unused
+LL |
 LL |     || {
    |     ^^
 
 error: item has unused generic parameters
-  --> $DIR/generators.rs:60:5
+  --> $DIR/generators.rs:34:8
+   |
+LL | pub fn unused_type<T>() -> impl Generator<(), Yield = u32, Return = u32> + Unpin {
+   |        ^^^^^^^^^^^ - generic parameter `T` is unused
+
+error: item has unused generic parameters
+  --> $DIR/generators.rs:62:5
    |
 LL | pub fn unused_const<const T: u32>() -> impl Generator<(), Yield = u32, Return = u32> + Unpin {
    |                     ------------ generic parameter `T` is unused
+LL |
 LL |     || {
    |     ^^
 
-error: aborting due to 2 previous errors; 1 warning emitted
+error: item has unused generic parameters
+  --> $DIR/generators.rs:60:8
+   |
+LL | pub fn unused_const<const T: u32>() -> impl Generator<(), Yield = u32, Return = u32> + Unpin {
+   |        ^^^^^^^^^^^^ ------------ generic parameter `T` is unused
+
+error: aborting due to 4 previous errors; 1 warning emitted
 

tests/ui/type-alias-impl-trait/destructure_tait-ice-113594.rs

@@ -0,0 +1,18 @@
+// build-pass
+
+#![feature(type_alias_impl_trait)]
+
+pub struct Foo {
+    /// This type must have nontrivial drop glue
+    field: String,
+}
+
+pub type Tait = impl Sized;
+
+pub fn ice_cold(beverage: Tait) {
+    // Must destructure at least one field of `Foo`
+    let Foo { field } = beverage;
+    _ = field;
+}
+
+fn main() {}