Unify all validity check intrinsics

Also merges the inhabitedness check into the query to further unify the
code paths.

4 files changed, 50 insertions, 62 deletions

diff --git a/compiler/rustc_const_eval/src/interpret/intrinsics.rs b/compiler/rustc_const_eval/src/interpret/intrinsics.rs
index 26c84b4ce61..c65d677e8ea 100644
--- a/compiler/rustc_const_eval/src/interpret/intrinsics.rs
+++ b/compiler/rustc_const_eval/src/interpret/intrinsics.rs
@@ -11,7 +11,7 @@ use rustc_middle::mir::{
     BinOp, NonDivergingIntrinsic,
 };
 use rustc_middle::ty;
-use rustc_middle::ty::layout::{InitKind, LayoutOf as _};
+use rustc_middle::ty::layout::{LayoutOf as _, ValidityRequirement};
 use rustc_middle::ty::subst::SubstsRef;
 use rustc_middle::ty::{Ty, TyCtxt};
 use rustc_span::symbol::{sym, Symbol};
@@ -418,57 +418,35 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
             | sym::assert_zero_valid
             | sym::assert_mem_uninitialized_valid => {
                 let ty = instance.substs.type_at(0);
-                let layout = self.layout_of(ty)?;
-
-                // For *all* intrinsics we first check `is_uninhabited` to give a more specific
-                // error message.
-                if layout.abi.is_uninhabited() {
-                    // The run-time intrinsic panics just to get a good backtrace; here we abort
-                    // since there is no problem showing a backtrace even for aborts.
-                    M::abort(
-                        self,
-                        format!(
+                let requirement = ValidityRequirement::from_intrinsic(intrinsic_name).unwrap();
+
+                let should_panic = !self
+                    .tcx
+                    .check_validity_requirement((requirement, self.param_env.and(ty)))
+                    .map_err(|_| err_inval!(TooGeneric))?;
+
+                if should_panic {
+                    let layout = self.layout_of(ty)?;
+
+                    let msg = match requirement {
+                        // For *all* intrinsics we first check `is_uninhabited` to give a more specific
+                        // error message.
+                        _ if layout.abi.is_uninhabited() => format!(
                             "aborted execution: attempted to instantiate uninhabited type `{}`",
                             ty
                         ),
-                    )?;
-                }
-
-                if intrinsic_name == sym::assert_zero_valid {
-                    let should_panic = !self
-                        .tcx
-                        .check_validity_of_init((InitKind::Zero, self.param_env.and(ty)))
-                        .map_err(|_| err_inval!(TooGeneric))?;
-
-                    if should_panic {
-                        M::abort(
-                            self,
-                            format!(
-                                "aborted execution: attempted to zero-initialize type `{}`, which is invalid",
-                                ty
-                            ),
-                        )?;
-                    }
-                }
+                        ValidityRequirement::Inhabited => bug!("handled earlier"),
+                        ValidityRequirement::Zero => format!(
+                            "aborted execution: attempted to zero-initialize type `{}`, which is invalid",
+                            ty
+                        ),
+                        ValidityRequirement::UninitMitigated0x01Fill => format!(
+                            "aborted execution: attempted to leave type `{}` uninitialized, which is invalid",
+                            ty
+                        ),
+                    };
 
-                if intrinsic_name == sym::assert_mem_uninitialized_valid {
-                    let should_panic = !self
-                        .tcx
-                        .check_validity_of_init((
-                            InitKind::UninitMitigated0x01Fill,
-                            self.param_env.and(ty),
-                        ))
-                        .map_err(|_| err_inval!(TooGeneric))?;
-
-                    if should_panic {
-                        M::abort(
-                            self,
-                            format!(
-                                "aborted execution: attempted to leave type `{}` uninitialized, which is invalid",
-                                ty
-                            ),
-                        )?;
-                    }
+                    M::abort(self, msg)?;
                 }
             }
             sym::simd_insert => {
diff --git a/compiler/rustc_const_eval/src/lib.rs b/compiler/rustc_const_eval/src/lib.rs
index 092a7dc3d3b..ed9efe568fb 100644
--- a/compiler/rustc_const_eval/src/lib.rs
+++ b/compiler/rustc_const_eval/src/lib.rs
@@ -61,7 +61,7 @@ pub fn provide(providers: &mut Providers) {
         let (param_env, value) = param_env_and_value.into_parts();
         const_eval::deref_mir_constant(tcx, param_env, value)
     };
-    providers.check_validity_of_init = |tcx, (init_kind, param_env_and_ty)| {
-        util::might_permit_raw_init(tcx, init_kind, param_env_and_ty)
+    providers.check_validity_requirement = |tcx, (init_kind, param_env_and_ty)| {
+        util::check_validity_requirement(tcx, init_kind, param_env_and_ty)
     };
 }
diff --git a/compiler/rustc_const_eval/src/util/might_permit_raw_init.rs b/compiler/rustc_const_eval/src/util/check_validity_requirement.rs
index a78bf927ca1..dcd15b919f4 100644
--- a/compiler/rustc_const_eval/src/util/might_permit_raw_init.rs
+++ b/compiler/rustc_const_eval/src/util/check_validity_requirement.rs
@@ -1,4 +1,4 @@
-use rustc_middle::ty::layout::{InitKind, LayoutCx, LayoutError, LayoutOf, TyAndLayout};
+use rustc_middle::ty::layout::{LayoutCx, LayoutError, LayoutOf, TyAndLayout, ValidityRequirement};
 use rustc_middle::ty::{ParamEnv, ParamEnvAnd, Ty, TyCtxt};
 use rustc_session::Limit;
 use rustc_target::abi::{Abi, FieldsShape, Scalar, Variants};
@@ -18,16 +18,23 @@ use crate::interpret::{InterpCx, MemoryKind, OpTy};
 /// Rust UB as long as there is no risk of miscompilations. The `strict_init_checks` can be set to
 /// do a full check against Rust UB instead (in which case we will also ignore the 0x01-filling and
 /// to the full uninit check).
-pub fn might_permit_raw_init<'tcx>(
+pub fn check_validity_requirement<'tcx>(
     tcx: TyCtxt<'tcx>,
-    kind: InitKind,
+    kind: ValidityRequirement,
     param_env_and_ty: ParamEnvAnd<'tcx, Ty<'tcx>>,
 ) -> Result<bool, LayoutError<'tcx>> {
+    let layout = tcx.layout_of(param_env_and_ty)?;
+
+    // There is nothing strict or lax about inhabitedness.
+    if kind == ValidityRequirement::Inhabited {
+        return Ok(!layout.abi.is_uninhabited());
+    }
+
     if tcx.sess.opts.unstable_opts.strict_init_checks {
-        might_permit_raw_init_strict(tcx.layout_of(param_env_and_ty)?, tcx, kind)
+        might_permit_raw_init_strict(layout, tcx, kind)
     } else {
         let layout_cx = LayoutCx { tcx, param_env: param_env_and_ty.param_env };
-        might_permit_raw_init_lax(tcx.layout_of(param_env_and_ty)?, &layout_cx, kind)
+        might_permit_raw_init_lax(layout, &layout_cx, kind)
     }
 }
 
@@ -36,7 +43,7 @@ pub fn might_permit_raw_init<'tcx>(
 fn might_permit_raw_init_strict<'tcx>(
     ty: TyAndLayout<'tcx>,
     tcx: TyCtxt<'tcx>,
-    kind: InitKind,
+    kind: ValidityRequirement,
 ) -> Result<bool, LayoutError<'tcx>> {
     let machine = CompileTimeInterpreter::new(
         Limit::new(0),
@@ -50,7 +57,7 @@ fn might_permit_raw_init_strict<'tcx>(
         .allocate(ty, MemoryKind::Machine(crate::const_eval::MemoryKind::Heap))
         .expect("OOM: failed to allocate for uninit check");
 
-    if kind == InitKind::Zero {
+    if kind == ValidityRequirement::Zero {
         cx.write_bytes_ptr(
             allocated.ptr,
             std::iter::repeat(0_u8).take(ty.layout.size().bytes_usize()),
@@ -72,15 +79,18 @@ fn might_permit_raw_init_strict<'tcx>(
 fn might_permit_raw_init_lax<'tcx>(
     this: TyAndLayout<'tcx>,
     cx: &LayoutCx<'tcx, TyCtxt<'tcx>>,
-    init_kind: InitKind,
+    init_kind: ValidityRequirement,
 ) -> Result<bool, LayoutError<'tcx>> {
     let scalar_allows_raw_init = move |s: Scalar| -> bool {
         match init_kind {
-            InitKind::Zero => {
+            ValidityRequirement::Inhabited => {
+                bug!("ValidityRequirement::Inhabited should have been handled above")
+            }
+            ValidityRequirement::Zero => {
                 // The range must contain 0.
                 s.valid_range(cx).contains(0)
             }
-            InitKind::UninitMitigated0x01Fill => {
+            ValidityRequirement::UninitMitigated0x01Fill => {
                 // The range must include an 0x01-filled buffer.
                 let mut val: u128 = 0x01;
                 for _ in 1..s.size(cx).bytes() {
diff --git a/compiler/rustc_const_eval/src/util/mod.rs b/compiler/rustc_const_eval/src/util/mod.rs
index 51735e33e0f..c0aabd77cee 100644
--- a/compiler/rustc_const_eval/src/util/mod.rs
+++ b/compiler/rustc_const_eval/src/util/mod.rs
@@ -1,14 +1,14 @@
 mod alignment;
 mod call_kind;
+mod check_validity_requirement;
 pub mod collect_writes;
 mod compare_types;
 mod find_self_call;
-mod might_permit_raw_init;
 mod type_name;
 
 pub use self::alignment::is_disaligned;
 pub use self::call_kind::{call_kind, CallDesugaringKind, CallKind};
+pub use self::check_validity_requirement::check_validity_requirement;
 pub use self::compare_types::{is_equal_up_to_subtyping, is_subtype};
 pub use self::find_self_call::find_self_call;
-pub use self::might_permit_raw_init::might_permit_raw_init;
 pub use self::type_name::type_name;