Add Drop terminator to SMIR

Author: spastorino

compiler/rustc_smir/src/rustc_smir/mod.rs

@@ -162,7 +162,11 @@ fn rustc_terminator_to_terminator(
         Terminate => Terminator::Abort,
         Return => Terminator::Return,
         Unreachable => Terminator::Unreachable,
-        Drop { .. } => todo!(),
+        Drop { place, target, unwind } => Terminator::Drop {
+            place: rustc_place_to_place(place),
+            target: target.as_usize(),
+            unwind: rustc_unwind_to_unwind(unwind),
+        },
         Call { func, args, destination, target, unwind, from_hir_call: _, fn_span: _ } => {
             Terminator::Call {
                 func: rustc_op_to_op(func),

compiler/rustc_smir/src/stable_mir/mir/body.rs

@@ -26,7 +26,7 @@ pub enum Terminator {
     Drop {
         place: Place,
         target: usize,
-        unwind: Option<usize>,
+        unwind: UnwindAction,
     },
     Call {
         func: Operand,

tests/ui-fulldeps/stable-mir/crate-info.rs

@@ -60,6 +60,15 @@ fn test_stable_mir(tcx: TyCtxt<'_>) {
         stable_mir::mir::Terminator::Call { .. } => {}
         other => panic!("{other:?}"),
     }
+
+    let drop = get_item(tcx, &items, (DefKind::Fn, "drop")).unwrap();
+    let body = drop.body();
+    assert_eq!(body.blocks.len(), 2);
+    let block = &body.blocks[0];
+    match &block.terminator {
+        stable_mir::mir::Terminator::Drop { .. } => {}
+        other => panic!("{other:?}"),
+    }
 }
 
 // Use internal API to find a function in a crate.
@@ -131,7 +140,9 @@ fn generate_input(path: &str) -> std::io::Result<()> {
         let x_64 = foo::bar(x);
         let y_64 = foo::bar(y);
         x_64.wrapping_add(y_64)
-    }}"#
+    }}
+
+    pub fn drop(_: String) {{}}"#
     )?;
     Ok(())
 }