Auto merge of rust-lang#61373 - tmandry:emit-storagedead-along-unwind…

…, r=eddyb

Emit StorageDead along unwind paths for generators

Completion of the work done in rust-lang#60840. That PR made a change to implicitly consider a local `StorageDead` after Drop, but that was incorrect for DropAndReplace (see also rust-lang#61060 which tried to fix this in a different way).

This finally enables the optimization implemented in rust-lang#60187.

r? @eddyb
cc @Zoxc @cramertj @RalfJung

src/librustc/ty/layout.rs

@@ -666,7 +666,7 @@ impl<'a, 'tcx> LayoutCx<'tcx, TyCtxt<'a, 'tcx, 'tcx>> {
                     size,
                     align,
                 });
-                debug!("generator layout: {:#?}", layout);
+                debug!("generator layout ({:?}): {:#?}", ty, layout);
                 layout
             }
 

src/librustc_mir/build/expr/as_temp.rs

@@ -1,7 +1,7 @@
 //! See docs in build/expr/mod.rs
 
 use crate::build::{BlockAnd, BlockAndExtension, Builder};
-use crate::build::scope::{CachedBlock, DropKind};
+use crate::build::scope::DropKind;
 use crate::hair::*;
 use rustc::middle::region;
 use rustc::mir::*;
@@ -103,9 +103,7 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
                 temp_lifetime,
                 temp_place,
                 expr_ty,
-                DropKind::Value {
-                    cached_block: CachedBlock::default(),
-                },
+                DropKind::Value,
             );
         }
 

src/librustc_mir/build/matches/mod.rs

@@ -5,7 +5,7 @@
 //! This also includes code for pattern bindings in `let` statements and
 //! function parameters.
 
-use crate::build::scope::{CachedBlock, DropKind};
+use crate::build::scope::DropKind;
 use crate::build::ForGuard::{self, OutsideGuard, RefWithinGuard};
 use crate::build::{BlockAnd, BlockAndExtension, Builder};
 use crate::build::{GuardFrame, GuardFrameLocal, LocalsForNode};
@@ -557,9 +557,7 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
             region_scope,
             &Place::Base(PlaceBase::Local(local_id)),
             var_ty,
-            DropKind::Value {
-                cached_block: CachedBlock::default(),
-            },
+            DropKind::Value,
         );
     }
 

src/librustc_mir/build/mod.rs

@@ -1,5 +1,5 @@
 use crate::build;
-use crate::build::scope::{CachedBlock, DropKind};
+use crate::build::scope::DropKind;
 use crate::hair::cx::Cx;
 use crate::hair::{LintLevel, BindingMode, PatternKind};
 use crate::shim;
@@ -912,8 +912,7 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
             // Make sure we drop (parts of) the argument even when not matched on.
             self.schedule_drop(
                 pattern.as_ref().map_or(ast_body.span, |pat| pat.span),
-                argument_scope, &place, ty,
-                DropKind::Value { cached_block: CachedBlock::default() },
+                argument_scope, &place, ty, DropKind::Value,
             );
 
             if let Some(pattern) = pattern {