drop redundant ParamEnv, and avoid constructing InternVisitor without visiting
diff --git a/src/librustc_mir/const_eval.rs b/src/librustc_mir/const_eval.rs
index 57ddaa4..3f53f84 100644
--- a/src/librustc_mir/const_eval.rs
+++ b/src/librustc_mir/const_eval.rs
@@ -134,9 +134,8 @@
ecx: &mut CompileTimeEvalContext<'mir, 'tcx>,
cid: GlobalId<'tcx>,
body: &'mir mir::Body<'tcx>,
- param_env: ty::ParamEnv<'tcx>,
) -> InterpResult<'tcx, MPlaceTy<'tcx>> {
- debug!("eval_body_using_ecx: {:?}, {:?}", cid, param_env);
+ debug!("eval_body_using_ecx: {:?}, {:?}", cid, ecx.param_env);
let tcx = ecx.tcx.tcx;
let layout = ecx.layout_of(body.return_ty().subst(tcx, cid.instance.substs))?;
assert!(!layout.is_unsized());
@@ -162,7 +161,6 @@
ecx,
cid.instance.def_id(),
ret,
- param_env,
)?;
debug!("eval_body_using_ecx done: {:?}", *ret);
@@ -658,7 +656,7 @@
let res = ecx.load_mir(cid.instance.def, cid.promoted);
res.and_then(
- |body| eval_body_using_ecx(&mut ecx, cid, body, key.param_env)
+ |body| eval_body_using_ecx(&mut ecx, cid, body)
).and_then(|place| {
Ok(RawConst {
alloc_id: place.ptr.assert_ptr().alloc_id,
diff --git a/src/librustc_mir/interpret/intern.rs b/src/librustc_mir/interpret/intern.rs
index 6333fce..b657a33 100644
--- a/src/librustc_mir/interpret/intern.rs
+++ b/src/librustc_mir/interpret/intern.rs
@@ -3,7 +3,7 @@
//! After a const evaluation has computed a value, before we destroy the const evaluator's session
//! memory, we need to extract all memory allocations to the global memory pool so they stay around.
-use rustc::ty::{Ty, ParamEnv, self};
+use rustc::ty::{Ty, self};
use rustc::mir::interpret::{InterpResult, ErrorHandled};
use rustc::hir;
use rustc::hir::def_id::DefId;
@@ -18,10 +18,10 @@
use crate::const_eval::{CompileTimeInterpreter, CompileTimeEvalContext};
struct InternVisitor<'rt, 'mir, 'tcx> {
- /// previously encountered safe references
- ref_tracking: &'rt mut RefTracking<(MPlaceTy<'tcx>, Mutability, InternMode)>,
+ /// The ectx from which we intern.
ecx: &'rt mut CompileTimeEvalContext<'mir, 'tcx>,
- param_env: ParamEnv<'tcx>,
+ /// Previously encountered safe references.
+ ref_tracking: &'rt mut RefTracking<(MPlaceTy<'tcx>, Mutability, InternMode)>,
/// The root node of the value that we're looking at. This field is never mutated and only used
/// for sanity assertions that will ICE when `const_qualif` screws up.
mode: InternMode,
@@ -53,74 +53,93 @@
/// into the memory of other constants or statics
struct IsStaticOrFn;
+/// Intern an allocation without looking at its children.
+/// `mode` is the mode of the environment where we found this pointer.
+/// `mutablity` is the mutability of the place to be interned; even if that says
+/// `immutable` things might become mutable if `ty` is not frozen.
+fn intern_shallow<'rt, 'mir, 'tcx>(
+ ecx: &'rt mut CompileTimeEvalContext<'mir, 'tcx>,
+ leftover_relocations: &'rt mut FxHashSet<AllocId>,
+ mode: InternMode,
+ alloc_id: AllocId,
+ mutability: Mutability,
+ ty: Option<Ty<'tcx>>,
+) -> InterpResult<'tcx, Option<IsStaticOrFn>> {
+ trace!(
+ "InternVisitor::intern {:?} with {:?}",
+ alloc_id, mutability,
+ );
+ // remove allocation
+ let tcx = ecx.tcx;
+ let memory = ecx.memory_mut();
+ let (kind, mut alloc) = match memory.alloc_map.remove(&alloc_id) {
+ Some(entry) => entry,
+ None => {
+ // Pointer not found in local memory map. It is either a pointer to the global
+ // map, or dangling.
+ // If the pointer is dangling (neither in local nor global memory), we leave it
+ // to validation to error. The `delay_span_bug` ensures that we don't forget such
+ // a check in validation.
+ if tcx.alloc_map.lock().get(alloc_id).is_none() {
+ tcx.sess.delay_span_bug(ecx.tcx.span, "tried to intern dangling pointer");
+ }
+ // treat dangling pointers like other statics
+ // just to stop trying to recurse into them
+ return Ok(Some(IsStaticOrFn));
+ },
+ };
+ // This match is just a canary for future changes to `MemoryKind`, which most likely need
+ // changes in this function.
+ match kind {
+ MemoryKind::Stack | MemoryKind::Vtable => {},
+ }
+ // Set allocation mutability as appropriate. This is used by LLVM to put things into
+ // read-only memory, and also by Miri when evluating other constants/statics that
+ // access this one.
+ if mode == InternMode::Static {
+ let frozen = ty.map_or(true, |ty| ty.is_freeze(
+ ecx.tcx.tcx,
+ ecx.param_env,
+ ecx.tcx.span,
+ ));
+ // For statics, allocation mutability is the combination of the place mutability and
+ // the type mutability.
+ // The entire allocation needs to be mutable if it contains an `UnsafeCell` anywhere.
+ if mutability == Mutability::Immutable && frozen {
+ alloc.mutability = Mutability::Immutable;
+ } else {
+ // Just making sure we are not "upgrading" an immutable allocation to mutable.
+ assert_eq!(alloc.mutability, Mutability::Mutable);
+ }
+ } else {
+ // We *could* be non-frozen at `ConstBase`, for constants like `Cell::new(0)`.
+ // But we still intern that as immutable as the memory cannot be changed once the
+ // initial value was computed.
+ // Constants are never mutable.
+ alloc.mutability = Mutability::Immutable;
+ };
+ // link the alloc id to the actual allocation
+ let alloc = tcx.intern_const_alloc(alloc);
+ leftover_relocations.extend(alloc.relocations().iter().map(|&(_, ((), reloc))| reloc));
+ tcx.alloc_map.lock().set_alloc_id_memory(alloc_id, alloc);
+ Ok(None)
+}
+
impl<'rt, 'mir, 'tcx> InternVisitor<'rt, 'mir, 'tcx> {
- /// Intern an allocation without looking at its children.
- /// `mutablity` is the mutability of the place to be interned; even if that says
- /// `immutable` things might become mutable if `ty` is not frozen.
fn intern_shallow(
&mut self,
alloc_id: AllocId,
mutability: Mutability,
ty: Option<Ty<'tcx>>,
) -> InterpResult<'tcx, Option<IsStaticOrFn>> {
- trace!(
- "InternVisitor::intern {:?} with {:?}",
- alloc_id, mutability,
- );
- // remove allocation
- let tcx = self.ecx.tcx;
- let memory = self.ecx.memory_mut();
- let (kind, mut alloc) = match memory.alloc_map.remove(&alloc_id) {
- Some(entry) => entry,
- None => {
- // Pointer not found in local memory map. It is either a pointer to the global
- // map, or dangling.
- // If the pointer is dangling (neither in local nor global memory), we leave it
- // to validation to error. The `delay_span_bug` ensures that we don't forget such
- // a check in validation.
- if tcx.alloc_map.lock().get(alloc_id).is_none() {
- tcx.sess.delay_span_bug(self.ecx.tcx.span, "tried to intern dangling pointer");
- }
- // treat dangling pointers like other statics
- // just to stop trying to recurse into them
- return Ok(Some(IsStaticOrFn));
- },
- };
- // This match is just a canary for future changes to `MemoryKind`, which most likely need
- // changes in this function.
- match kind {
- MemoryKind::Stack | MemoryKind::Vtable => {},
- }
- // Set allocation mutability as appropriate. This is used by LLVM to put things into
- // read-only memory, and also by Miri when evluating other constants/statics that
- // access this one.
- if self.mode == InternMode::Static {
- let frozen = ty.map_or(true, |ty| ty.is_freeze(
- self.ecx.tcx.tcx,
- self.param_env,
- self.ecx.tcx.span,
- ));
- // For statics, allocation mutability is the combination of the place mutability and
- // the type mutability.
- // The entire allocation needs to be mutable if it contains an `UnsafeCell` anywhere.
- if mutability == Mutability::Immutable && frozen {
- alloc.mutability = Mutability::Immutable;
- } else {
- // Just making sure we are not "upgrading" an immutable allocation to mutable.
- assert_eq!(alloc.mutability, Mutability::Mutable);
- }
- } else {
- // We *could* be non-frozen at `ConstBase`, for constants like `Cell::new(0)`.
- // But we still intern that as immutable as the memory cannot be changed once the
- // initial value was computed.
- // Constants are never mutable.
- alloc.mutability = Mutability::Immutable;
- };
- // link the alloc id to the actual allocation
- let alloc = tcx.intern_const_alloc(alloc);
- self.leftover_relocations.extend(alloc.relocations().iter().map(|&(_, ((), reloc))| reloc));
- tcx.alloc_map.lock().set_alloc_id_memory(alloc_id, alloc);
- Ok(None)
+ intern_shallow(
+ self.ecx,
+ self.leftover_relocations,
+ self.mode,
+ alloc_id,
+ mutability,
+ ty,
+ )
}
}
@@ -171,7 +190,8 @@
// Handle trait object vtables
if let Ok(meta) = value.to_meta() {
if let ty::Dynamic(..) =
- self.ecx.tcx.struct_tail_erasing_lifetimes(referenced_ty, self.param_env).sty
+ self.ecx.tcx.struct_tail_erasing_lifetimes(
+ referenced_ty, self.ecx.param_env).sty
{
if let Ok(vtable) = meta.unwrap().to_ptr() {
// explitly choose `Immutable` here, since vtables are immutable, even
@@ -203,7 +223,7 @@
(InternMode::Const, hir::Mutability::MutMutable) => {
match referenced_ty.sty {
ty::Array(_, n)
- if n.eval_usize(self.ecx.tcx.tcx, self.param_env) == 0 => {}
+ if n.eval_usize(self.ecx.tcx.tcx, self.ecx.param_env) == 0 => {}
ty::Slice(_)
if value.to_meta().unwrap().unwrap().to_usize(self.ecx)? == 0 => {}
_ => bug!("const qualif failed to prevent mutable references"),
@@ -246,9 +266,6 @@
ecx: &mut CompileTimeEvalContext<'mir, 'tcx>,
def_id: DefId,
ret: MPlaceTy<'tcx>,
- // FIXME(oli-obk): can we scrap the param env? I think we can, the final value of a const eval
- // must always be monomorphic, right?
- param_env: ty::ParamEnv<'tcx>,
) -> InterpResult<'tcx> {
let tcx = ecx.tcx;
// this `mutability` is the mutability of the place, ignoring the type
@@ -264,14 +281,14 @@
let leftover_relocations = &mut FxHashSet::default();
// start with the outermost allocation
- InternVisitor {
- ref_tracking: &mut ref_tracking,
+ intern_shallow(
ecx,
- mode: base_intern_mode,
leftover_relocations,
- param_env,
- mutability: base_mutability,
- }.intern_shallow(ret.ptr.to_ptr()?.alloc_id, base_mutability, Some(ret.layout.ty))?;
+ base_intern_mode,
+ ret.ptr.to_ptr()?.alloc_id,
+ base_mutability,
+ Some(ret.layout.ty)
+ )?;
while let Some(((mplace, mutability, mode), _)) = ref_tracking.todo.pop() {
let interned = InternVisitor {
@@ -279,7 +296,6 @@
ecx,
mode,
leftover_relocations,
- param_env,
mutability,
}.visit_value(mplace);
if let Err(error) = interned {
