Rollup of 6 pull requests

compiler/rustc_abi/src/lib.rs

@@ -833,6 +833,28 @@ pub enum Integer {
 }
 
 impl Integer {
+    pub fn int_ty_str(self) -> &'static str {
+        use Integer::*;
+        match self {
+            I8 => "i8",
+            I16 => "i16",
+            I32 => "i32",
+            I64 => "i64",
+            I128 => "i128",
+        }
+    }
+
+    pub fn uint_ty_str(self) -> &'static str {
+        use Integer::*;
+        match self {
+            I8 => "u8",
+            I16 => "u16",
+            I32 => "u32",
+            I64 => "u64",
+            I128 => "u128",
+        }
+    }
+
     #[inline]
     pub fn size(self) -> Size {
         use Integer::*;

compiler/rustc_codegen_cranelift/src/base.rs

@@ -785,8 +785,10 @@ fn codegen_stmt<'tcx>(
                 }
                 Rvalue::Repeat(ref operand, times) => {
                     let operand = codegen_operand(fx, operand);
-                    let times =
-                        fx.monomorphize(times).eval_target_usize(fx.tcx, ParamEnv::reveal_all());
+                    let times = fx
+                        .monomorphize(times)
+                        .try_to_target_usize(fx.tcx)
+                        .expect("expected monomorphic const in codegen");
                     if operand.layout().size.bytes() == 0 {
                         // Do nothing for ZST's
                     } else if fx.clif_type(operand.layout().ty) == Some(types::I8) {
@@ -944,7 +946,10 @@ fn codegen_stmt<'tcx>(
 fn codegen_array_len<'tcx>(fx: &mut FunctionCx<'_, '_, 'tcx>, place: CPlace<'tcx>) -> Value {
     match *place.layout().ty.kind() {
         ty::Array(_elem_ty, len) => {
-            let len = fx.monomorphize(len).eval_target_usize(fx.tcx, ParamEnv::reveal_all()) as i64;
+            let len = fx
+                .monomorphize(len)
+                .try_to_target_usize(fx.tcx)
+                .expect("expected monomorphic const in codegen") as i64;
             fx.bcx.ins().iconst(fx.pointer_type, len)
         }
         ty::Slice(_elem_ty) => place.to_ptr_unsized().1,

compiler/rustc_codegen_cranelift/src/debuginfo/types.rs

@@ -44,7 +44,7 @@ impl DebugContext {
                 type_dbg,
                 ty,
                 *elem_ty,
-                len.eval_target_usize(tcx, ty::ParamEnv::reveal_all()),
+                len.try_to_target_usize(tcx).expect("expected monomorphic const in codegen"),
             ),
             // ty::Slice(_) | ty::Str
             // ty::Dynamic

compiler/rustc_codegen_cranelift/src/intrinsics/simd.rs

@@ -131,9 +131,8 @@ pub(super) fn codegen_simd_intrinsic_call<'tcx>(
 
             let idx = generic_args[2]
                 .expect_const()
-                .eval(fx.tcx, ty::ParamEnv::reveal_all(), span)
-                .unwrap()
-                .1
+                .try_to_valtree()
+                .expect("expected monomorphic const in codegen")
                 .unwrap_branch();
 
             assert_eq!(x.layout(), y.layout());

compiler/rustc_codegen_cranelift/src/unsize.rs

@@ -24,10 +24,10 @@ pub(crate) fn unsized_info<'tcx>(
     let (source, target) =
         fx.tcx.struct_lockstep_tails_for_codegen(source, target, ParamEnv::reveal_all());
     match (&source.kind(), &target.kind()) {
-        (&ty::Array(_, len), &ty::Slice(_)) => fx
-            .bcx
-            .ins()
-            .iconst(fx.pointer_type, len.eval_target_usize(fx.tcx, ParamEnv::reveal_all()) as i64),
+        (&ty::Array(_, len), &ty::Slice(_)) => fx.bcx.ins().iconst(
+            fx.pointer_type,
+            len.try_to_target_usize(fx.tcx).expect("expected monomorphic const in codegen") as i64,
+        ),
         (&ty::Dynamic(data_a, _, src_dyn_kind), &ty::Dynamic(data_b, _, target_dyn_kind))
             if src_dyn_kind == target_dyn_kind =>
         {

compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs

@@ -125,7 +125,9 @@ fn build_fixed_size_array_di_node<'ll, 'tcx>(
 
     let (size, align) = cx.size_and_align_of(array_type);
 
-    let upper_bound = len.eval_target_usize(cx.tcx, ty::ParamEnv::reveal_all()) as c_longlong;
+    let upper_bound = len
+        .try_to_target_usize(cx.tcx)
+        .expect("expected monomorphic const in codegen") as c_longlong;
 
     let subrange =
         unsafe { Some(llvm::LLVMRustDIBuilderGetOrCreateSubrange(DIB(cx), 0, upper_bound)) };

compiler/rustc_codegen_ssa/src/base.rs

@@ -115,9 +115,9 @@ fn unsized_info<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
     let (source, target) =
         cx.tcx().struct_lockstep_tails_for_codegen(source, target, bx.param_env());
     match (source.kind(), target.kind()) {
-        (&ty::Array(_, len), &ty::Slice(_)) => {
-            cx.const_usize(len.eval_target_usize(cx.tcx(), ty::ParamEnv::reveal_all()))
-        }
+        (&ty::Array(_, len), &ty::Slice(_)) => cx.const_usize(
+            len.try_to_target_usize(cx.tcx()).expect("expected monomorphic const in codegen"),
+        ),
         (&ty::Dynamic(data_a, _, src_dyn_kind), &ty::Dynamic(data_b, _, target_dyn_kind))
             if src_dyn_kind == target_dyn_kind =>
         {

compiler/rustc_codegen_ssa/src/debuginfo/type_names.rs

@@ -188,7 +188,8 @@ fn push_debuginfo_type_name<'tcx>(
                     _ => write!(
                         output,
                         ",{}>",
-                        len.eval_target_usize(tcx, ty::ParamEnv::reveal_all())
+                        len.try_to_target_usize(tcx)
+                            .expect("expected monomorphic const in codegen")
                     )
                     .unwrap(),
                 }
@@ -200,7 +201,8 @@ fn push_debuginfo_type_name<'tcx>(
                     _ => write!(
                         output,
                         "; {}]",
-                        len.eval_target_usize(tcx, ty::ParamEnv::reveal_all())
+                        len.try_to_target_usize(tcx)
+                            .expect("expected monomorphic const in codegen")
                     )
                     .unwrap(),
                 }

compiler/rustc_codegen_ssa/src/mir/rvalue.rs

@@ -114,7 +114,8 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
 
                 let count = self
                     .monomorphize(count)
-                    .eval_target_usize(bx.cx().tcx(), ty::ParamEnv::reveal_all());
+                    .try_to_target_usize(bx.tcx())
+                    .expect("expected monomorphic const in codegen");
 
                 bx.write_operand_repeatedly(cg_elem, count, dest);
             }
@@ -803,7 +804,9 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
         if let Some(index) = place.as_local() {
             if let LocalRef::Operand(op) = self.locals[index] {
                 if let ty::Array(_, n) = op.layout.ty.kind() {
-                    let n = n.eval_target_usize(bx.cx().tcx(), ty::ParamEnv::reveal_all());
+                    let n = n
+                        .try_to_target_usize(bx.tcx())
+                        .expect("expected monomorphic const in codegen");
                     return bx.cx().const_usize(n);
                 }
             }

compiler/rustc_hir_typeck/src/pat.rs

@@ -11,7 +11,6 @@ use rustc_hir::def::{CtorKind, DefKind, Res};
 use rustc_hir::pat_util::EnumerateAndAdjustIterator;
 use rustc_hir::{self as hir, BindingMode, ByRef, HirId, LangItem, Mutability, Pat, PatKind};
 use rustc_infer::infer;
-use rustc_middle::mir::interpret::ErrorHandled;
 use rustc_middle::ty::{self, Ty, TypeVisitableExt};
 use rustc_middle::{bug, span_bug};
 use rustc_session::lint::builtin::NON_EXHAUSTIVE_OMITTED_PATTERNS;
@@ -2413,17 +2412,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         len: ty::Const<'tcx>,
         min_len: u64,
     ) -> (Option<Ty<'tcx>>, Ty<'tcx>) {
-        let len = match len.eval(self.tcx, self.param_env, span) {
-            Ok((_, val)) => val
-                .try_to_scalar()
-                .and_then(|scalar| scalar.try_to_scalar_int().ok())
-                .map(|int| int.to_target_usize(self.tcx)),
-            Err(ErrorHandled::Reported(..)) => {
-                let guar = self.error_scrutinee_unfixed_length(span);
-                return (Some(Ty::new_error(self.tcx, guar)), arr_ty);
-            }
-            Err(ErrorHandled::TooGeneric(..)) => None,
-        };
+        let len = len.try_eval_target_usize(self.tcx, self.param_env);
 
         let guar = if let Some(len) = len {
             // Now we know the length...

compiler/rustc_hir_typeck/src/writeback.rs

@@ -803,7 +803,7 @@ impl<'cx, 'tcx> Resolver<'cx, 'tcx> {
         // We must deeply normalize in the new solver, since later lints
         // expect that types that show up in the typeck are fully
         // normalized.
-        let value = if self.should_normalize {
+        let mut value = if self.should_normalize {
             let body_id = tcx.hir().body_owner_def_id(self.body.id());
             let cause = ObligationCause::misc(self.span.to_span(tcx), body_id);
             let at = self.fcx.at(&cause, self.fcx.param_env);
@@ -818,12 +818,27 @@ impl<'cx, 'tcx> Resolver<'cx, 'tcx> {
             value
         };
 
+        // Bail if there are any non-region infer.
         if value.has_non_region_infer() {
             let guar = self.report_error(value);
-            new_err(tcx, guar)
-        } else {
-            tcx.fold_regions(value, |_, _| tcx.lifetimes.re_erased)
+            value = new_err(tcx, guar);
+        }
+
+        // Erase the regions from the ty, since it's not really meaningful what
+        // these region values are; there's not a trivial correspondence between
+        // regions in the HIR and MIR, so when we turn the body into MIR, there's
+        // no reason to keep regions around. They will be repopulated during MIR
+        // borrowck, and specifically region constraints will be populated during
+        // MIR typeck which is run on the new body.
+        value = tcx.fold_regions(value, |_, _| tcx.lifetimes.re_erased);
+
+        // Normalize consts in writeback, because GCE doesn't normalize eagerly.
+        if tcx.features().generic_const_exprs {
+            value =
+                value.fold_with(&mut EagerlyNormalizeConsts { tcx, param_env: self.fcx.param_env });
         }
+
+        value
     }
 }
 
@@ -858,3 +873,17 @@ impl<'cx, 'tcx> TypeFolder<TyCtxt<'tcx>> for Resolver<'cx, 'tcx> {
         predicate
     }
 }
+
+struct EagerlyNormalizeConsts<'tcx> {
+    tcx: TyCtxt<'tcx>,
+    param_env: ty::ParamEnv<'tcx>,
+}
+impl<'tcx> TypeFolder<TyCtxt<'tcx>> for EagerlyNormalizeConsts<'tcx> {
+    fn cx(&self) -> TyCtxt<'tcx> {
+        self.tcx
+    }
+
+    fn fold_const(&mut self, ct: ty::Const<'tcx>) -> ty::Const<'tcx> {
+        self.tcx.try_normalize_erasing_regions(self.param_env, ct).unwrap_or(ct)
+    }
+}

compiler/rustc_lint/messages.ftl

@@ -395,6 +395,8 @@ lint_improper_ctypes_opaque = opaque types have no C equivalent
 lint_improper_ctypes_pat_help = consider using the base type instead
 
 lint_improper_ctypes_pat_reason = pattern types have no C equivalent
+
+lint_improper_ctypes_recursion_limit_reached = type is infinitely recursive
 lint_improper_ctypes_slice_help = consider using a raw pointer instead
 
 lint_improper_ctypes_slice_reason = slices have no C equivalent