miri: move param_env from Machine to EvalContext.

Author: eddyb

src/librustc/mir/interpret/const_eval.rs

@@ -20,7 +20,7 @@ pub fn eval_body<'a, 'tcx>(
 ) -> (EvalResult<'tcx, (PtrAndAlign, Ty<'tcx>)>, EvalContext<'a, 'tcx, CompileTimeFunctionEvaluator>) {
     debug!("eval_body: {:?}, {:?}", instance, param_env);
     let limits = super::ResourceLimits::default();
-    let mut ecx = EvalContext::<CompileTimeFunctionEvaluator>::new(tcx, limits, param_env, ());
+    let mut ecx = EvalContext::<CompileTimeFunctionEvaluator>::new(tcx, param_env, limits, (), ());
     let cid = GlobalId {
         instance,
         promoted: None,
@@ -165,14 +165,9 @@ impl Error for ConstEvalError {
 }
 
 impl<'tcx> super::Machine<'tcx> for CompileTimeFunctionEvaluator {
-    type Data = ty::ParamEnv<'tcx>;
+    type Data = ();
     type MemoryData = ();
     type MemoryKinds = !;
-    fn param_env<'a>(
-        ecx: &EvalContext<'a, 'tcx, Self>,
-    ) -> ty::ParamEnv<'tcx> {
-        ecx.machine_data
-    }
     fn eval_fn_call<'a>(
         ecx: &mut EvalContext<'a, 'tcx, Self>,
         instance: ty::Instance<'tcx>,

src/librustc/mir/interpret/eval_context.rs

@@ -25,6 +25,9 @@ pub struct EvalContext<'a, 'tcx: 'a, M: Machine<'tcx>> {
     /// The results of the type checker, from rustc.
     pub tcx: TyCtxt<'a, 'tcx, 'tcx>,
 
+    /// Bounds in scope for polymorphic evaluations.
+    pub param_env: ty::ParamEnv<'tcx>,
+
     /// The virtual memory system.
     pub memory: Memory<'a, 'tcx, M>,
 
@@ -194,7 +197,7 @@ impl<'a, 'tcx, M: Machine<'tcx>> LayoutOf<Ty<'tcx>> for &'a EvalContext<'a, 'tcx
     type TyLayout = EvalResult<'tcx, TyLayout<'tcx>>;
 
     fn layout_of(self, ty: Ty<'tcx>) -> Self::TyLayout {
-        (self.tcx, M::param_env(self)).layout_of(ty)
+        (self.tcx, self.param_env).layout_of(ty)
             .map_err(|layout| EvalErrorKind::Layout(layout).into())
     }
 }
@@ -212,13 +215,15 @@ impl<'c, 'b, 'a, 'tcx, M: Machine<'tcx>> LayoutOf<Ty<'tcx>>
 impl<'a, 'tcx, M: Machine<'tcx>> EvalContext<'a, 'tcx, M> {
     pub fn new(
         tcx: TyCtxt<'a, 'tcx, 'tcx>,
+        param_env: ty::ParamEnv<'tcx>,
         limits: ResourceLimits,
         machine_data: M::Data,
         memory_data: M::MemoryData,
     ) -> Self {
         EvalContext {
             machine_data,
             tcx,
+            param_env,
             memory: Memory::new(tcx, limits.memory_size, memory_data),
             suspended: HashMap::new(),
             stack: Vec::new(),
@@ -302,14 +307,14 @@ impl<'a, 'tcx, M: Machine<'tcx>> EvalContext<'a, 'tcx, M> {
         let substs = self.tcx.trans_apply_param_substs(self.substs(), &substs);
         ty::Instance::resolve(
             self.tcx,
-            M::param_env(self),
+            self.param_env,
             def_id,
             substs,
         ).ok_or(EvalErrorKind::TypeckError.into()) // turn error prop into a panic to expose associated type in const issue
     }
 
     pub(super) fn type_is_sized(&self, ty: Ty<'tcx>) -> bool {
-        ty.is_sized(self.tcx, M::param_env(self), DUMMY_SP)
+        ty.is_sized(self.tcx, self.param_env, DUMMY_SP)
     }
 
     pub fn load_mir(

src/librustc/mir/interpret/machine.rs

@@ -21,11 +21,6 @@ pub trait Machine<'tcx>: Sized {
     /// Additional memory kinds a machine wishes to distinguish from the builtin ones
     type MemoryKinds: ::std::fmt::Debug + PartialEq + Copy + Clone;
 
-    /// Produces the param env for this computation.
-    fn param_env<'a>(
-        ecx: &EvalContext<'a, 'tcx, Self>,
-    ) -> ty::ParamEnv<'tcx>;
-
     /// Entry point to all function calls.
     ///
     /// Returns Ok(true) when the function was handled completely

src/librustc/mir/interpret/step.rs

@@ -188,11 +188,7 @@ impl<'a, 'tcx, M: Machine<'tcx>> EvalContext<'a, 'tcx, M> {
                 aligned: !layout.is_packed(),
             },
         );
-        let internally_mutable = !layout.ty.is_freeze(
-            self.tcx,
-            M::param_env(self),
-            span,
-        );
+        let internally_mutable = !layout.ty.is_freeze(self.tcx, self.param_env, span);
         let mutability = if mutability == Mutability::Mutable || internally_mutable {
             Mutability::Mutable
         } else {
@@ -245,10 +241,10 @@ impl<'a, 'b, 'tcx, M: Machine<'tcx>> Visitor<'tcx> for ConstantExtractor<'a, 'b,
                     debug!("global_item: {:?}, {:#?}", def_id, substs);
                     let substs = this.ecx.tcx.trans_apply_param_substs(this.instance.substs, &substs);
                     debug!("global_item_new_substs: {:#?}", substs);
-                    debug!("global_item_param_env: {:#?}", M::param_env(this.ecx));
+                    debug!("global_item_param_env: {:#?}", this.ecx.param_env);
                     let instance = Instance::resolve(
                         this.ecx.tcx,
-                        M::param_env(this.ecx),
+                        this.ecx.param_env,
                         def_id,
                         substs,
                     ).ok_or(EvalErrorKind::TypeckError)?; // turn error prop into a panic to expose associated type in const issue

src/librustc_const_eval/eval.rs

@@ -24,7 +24,7 @@ use rustc::util::common::ErrorReported;
 use rustc::util::nodemap::NodeMap;
 
 use rustc::mir::interpret::{PrimVal, Value, PtrAndAlign, HasMemory, EvalError};
-use rustc::mir::interpret::{CompileTimeFunctionEvaluator, EvalContext, Machine};
+use rustc::mir::interpret::{CompileTimeFunctionEvaluator, EvalContext};
 use rustc::mir::Field;
 use rustc::mir::interpret::{Place, PlaceExtra};
 use rustc_data_structures::indexed_vec::Idx;
@@ -937,7 +937,7 @@ fn check_ctfe_against_miri<'a, 'tcx>(
                 ConstVal::Function(did, substs) => {
                     let ctfe = ty::Instance::resolve(
                         ecx.tcx,
-                        CompileTimeFunctionEvaluator::param_env(&ecx),
+                        ecx.param_env,
                         did,
                         substs,
                     ).unwrap();