Auto merge of #2935 - RalfJung:rustup, r=RalfJung

Rustup

3 files changed, 7 insertions, 9 deletions

diff --git a/compiler/rustc_mir_transform/src/check_alignment.rs b/compiler/rustc_mir_transform/src/check_alignment.rs
index fd349c07040..856327e6ce6 100644
--- a/compiler/rustc_mir_transform/src/check_alignment.rs
+++ b/compiler/rustc_mir_transform/src/check_alignment.rs
@@ -9,7 +9,6 @@ use rustc_middle::mir::{
 };
 use rustc_middle::ty::{Ty, TyCtxt, TypeAndMut};
 use rustc_session::Session;
-use rustc_target::spec::PanicStrategy;
 
 pub struct CheckAlignment;
 
@@ -241,11 +240,10 @@ fn insert_alignment_check<'tcx>(
                 required: Operand::Copy(alignment),
                 found: Operand::Copy(addr),
             }),
-            unwind: if tcx.sess.panic_strategy() == PanicStrategy::Unwind {
-                UnwindAction::Terminate
-            } else {
-                UnwindAction::Unreachable
-            },
+            // The panic symbol that this calls is #[rustc_nounwind]. We never want to insert an
+            // unwind into unsafe code, because unwinding could make a failing UB check turn into
+            // much worse UB when we start unwinding.
+            unwind: UnwindAction::Unreachable,
         },
     });
 }
diff --git a/compiler/rustc_mir_transform/src/const_prop.rs b/compiler/rustc_mir_transform/src/const_prop.rs
index 1d43dbda0aa..2f2c7357b00 100644
--- a/compiler/rustc_mir_transform/src/const_prop.rs
+++ b/compiler/rustc_mir_transform/src/const_prop.rs
@@ -118,8 +118,8 @@ impl<'tcx> MirPass<'tcx> for ConstProp {
 
         // Traverse the body in reverse post-order, to ensure that `FullConstProp` locals are
         // assigned before being read.
-        let postorder = body.basic_blocks.postorder().to_vec();
-        for bb in postorder.into_iter().rev() {
+        let rpo = body.basic_blocks.reverse_postorder().to_vec();
+        for bb in rpo {
             let data = &mut body.basic_blocks.as_mut_preserves_cfg()[bb];
             optimization_finder.visit_basic_block_data(bb, data);
         }
diff --git a/compiler/rustc_mir_transform/src/prettify.rs b/compiler/rustc_mir_transform/src/prettify.rs
index 6f46974ea00..745fa30841c 100644
--- a/compiler/rustc_mir_transform/src/prettify.rs
+++ b/compiler/rustc_mir_transform/src/prettify.rs
@@ -24,7 +24,7 @@ impl<'tcx> MirPass<'tcx> for ReorderBasicBlocks {
 
     fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
         let rpo: IndexVec<BasicBlock, BasicBlock> =
-            body.basic_blocks.postorder().iter().copied().rev().collect();
+            body.basic_blocks.reverse_postorder().iter().copied().collect();
         if rpo.iter().is_sorted() {
             return;
         }