Initialize MemoryExtra with StdRng

Author: pvdrz

src/lib.rs

@@ -50,7 +50,7 @@ use crate::range_map::RangeMap;
 pub use crate::helpers::{EvalContextExt as HelpersEvalContextExt};
 use crate::mono_hash_map::MonoHashMap;
 pub use crate::stacked_borrows::{EvalContextExt as StackedBorEvalContextExt};
-use crate::memory::AllocExtra;
+use crate::memory::{MemoryExtra, AllocExtra};
 
 // Used by priroda.
 pub use crate::stacked_borrows::{Tag, Permission, Stack, Stacks, Item};
@@ -83,10 +83,8 @@ pub fn create_ecx<'mir, 'tcx: 'mir>(
         tcx.at(syntax::source_map::DUMMY_SP),
         ty::ParamEnv::reveal_all(),
         Evaluator::new(config.validate),
+        MemoryExtra::with_rng(config.seed.map(StdRng::seed_from_u64)),
     );
-
-    // FIXME: InterpretCx::new should take an initial MemoryExtra
-    ecx.memory_mut().extra.rng = config.seed.map(StdRng::seed_from_u64);
 
     let main_instance = ty::Instance::mono(ecx.tcx.tcx, main_id);
     let main_mir = ecx.load_mir(main_instance.def)?;

src/memory.rs

@@ -15,6 +15,16 @@ pub struct MemoryExtra {
     pub(crate) rng: Option<StdRng>
 }
 
+impl MemoryExtra {
+    pub fn with_rng(rng: Option<StdRng>) -> Self {
+        MemoryExtra {
+            stacked_borrows: Default::default(),
+            intptrcast: Default::default(),
+            rng,
+        }
+    }
+}
+
 #[derive(Debug, Clone)]
 pub struct AllocExtra {
     pub stacked_borrows: stacked_borrows::AllocExtra,