simplify the interpreter locals, since they always must be backed by an allocation

Author: oli-obk

Diff for: src/interpreter/mod.rs

@@ -86,7 +86,7 @@ pub struct Frame<'tcx> {
     /// This is pure interpreter magic and has nothing to do with how rustc does it
     /// An example is calling an FnMut closure that has been converted to a FnOnce closure
     /// If they are Value::ByRef, their memory will be freed when the stackframe finishes
-    pub interpreter_temporaries: Vec<Value>,
+    pub interpreter_temporaries: Vec<Pointer>,
 
     ////////////////////////////////////////////////////////////////////////////////
     // Current position within the function
@@ -333,7 +333,7 @@ impl<'a, 'tcx> EvalContext<'a, 'tcx> {
         substs: &'tcx Substs<'tcx>,
         return_lvalue: Lvalue<'tcx>,
         return_to_block: StackPopCleanup,
-        temporaries: Vec<Value>,
+        temporaries: Vec<Pointer>,
     ) -> EvalResult<'tcx, ()> {
         ::log_settings::settings().indentation += 1;
 
@@ -393,8 +393,9 @@ impl<'a, 'tcx> EvalContext<'a, 'tcx> {
             StackPopCleanup::None => {},
         }
         // deallocate all locals that are backed by an allocation
-        for local in frame.locals.into_iter().filter_map(|l| l).chain(frame.interpreter_temporaries) {
-            if let Value::ByRef(ptr) = local {
+        for local in frame.locals.into_iter() {
+            if let Some(Value::ByRef(ptr)) = local {
+                trace!("deallocating local");
                 self.memory.dump(ptr.alloc_id);
                 match self.memory.deallocate(ptr) {
                     // Any frozen memory means that it belongs to a constant or something referenced
@@ -406,6 +407,12 @@ impl<'a, 'tcx> EvalContext<'a, 'tcx> {
                 }
             }
         }
+        // deallocate all temporary allocations
+        for ptr in frame.interpreter_temporaries {
+            trace!("deallocating temporary allocation");
+            self.memory.dump(ptr.alloc_id);
+            self.memory.deallocate(ptr)?;
+        }
         Ok(())
     }
 

Diff for: src/interpreter/terminator/mod.rs

@@ -432,7 +432,7 @@ impl<'a, 'tcx> EvalContext<'a, 'tcx> {
         def_id: DefId,
         substs: &'tcx Substs<'tcx>,
         args: &mut Vec<(Value, Ty<'tcx>)>,
-    ) -> EvalResult<'tcx, (DefId, &'tcx Substs<'tcx>, Vec<Value>)> {
+    ) -> EvalResult<'tcx, (DefId, &'tcx Substs<'tcx>, Vec<Pointer>)> {
         let trait_ref = ty::TraitRef::from_method(self.tcx, trait_id, substs);
         let trait_ref = self.tcx.normalize_associated_type(&ty::Binder(trait_ref));
 
@@ -481,13 +481,13 @@ impl<'a, 'tcx> EvalContext<'a, 'tcx> {
                                 let ptr = self.alloc_ptr(args[0].1)?;
                                 let kind = self.ty_to_primval_kind(args[0].1)?;
                                 self.memory.write_primval(ptr, primval, kind)?;
-                                temporaries.push(Value::ByRef(ptr));
+                                temporaries.push(ptr);
                                 ptr
                             },
                             Value::ByValPair(a, b) => {
                                 let ptr = self.alloc_ptr(args[0].1)?;
                                 self.write_pair_to_ptr(a, b, ptr, args[0].1)?;
-                                temporaries.push(Value::ByRef(ptr));
+                                temporaries.push(ptr);
                                 ptr
                             },
                         };