add error_occured field to ConstQualifs, fix rust-lang#76064

Author: vn-ki

compiler/rustc_middle/src/mir/query.rs

@@ -233,14 +233,15 @@ pub struct BorrowCheckResult<'tcx> {
 
 /// The result of the `mir_const_qualif` query.
 ///
-/// Each field corresponds to an implementer of the `Qualif` trait in
-/// `librustc_mir/transform/check_consts/qualifs.rs`. See that file for more information on each
+/// Each field (except `error_occured`) corresponds to an implementer of the `Qualif` trait in
+/// `rustc_mir/src/transform/check_consts/qualifs.rs`. See that file for more information on each
 /// `Qualif`.
 #[derive(Clone, Copy, Debug, Default, TyEncodable, TyDecodable, HashStable)]
 pub struct ConstQualifs {
     pub has_mut_interior: bool,
     pub needs_drop: bool,
     pub custom_eq: bool,
+    pub error_occured: bool,
 }
 
 /// After we borrow check a closure, we are left with various

compiler/rustc_mir/src/const_eval/eval_queries.rs

@@ -9,6 +9,7 @@ use crate::interpret::{
 use rustc_hir::def::DefKind;
 use rustc_middle::mir;
 use rustc_middle::mir::interpret::ErrorHandled;
+use rustc_errors::ErrorReported;
 use rustc_middle::traits::Reveal;
 use rustc_middle::ty::print::with_no_trimmed_paths;
 use rustc_middle::ty::{self, subst::Subst, TyCtxt};
@@ -274,6 +275,10 @@ pub fn eval_to_allocation_raw_provider<'tcx>(
                 return Err(ErrorHandled::Reported(error_reported));
             }
         }
+        let qualif = tcx.mir_const_qualif_opt_const_arg(def);
+        if qualif.error_occured {
+            return Err(ErrorHandled::Reported(ErrorReported {}));
+        }
     }
 
     let is_static = tcx.is_static(def.did);

compiler/rustc_mir/src/transform/check_consts/qualifs.rs

@@ -9,11 +9,12 @@ use rustc_trait_selection::traits;
 
 use super::ConstCx;
 
-pub fn in_any_value_of_ty(cx: &ConstCx<'_, 'tcx>, ty: Ty<'tcx>) -> ConstQualifs {
+pub fn in_any_value_of_ty(cx: &ConstCx<'_, 'tcx>, ty: Ty<'tcx>, error_occured: bool) -> ConstQualifs {
     ConstQualifs {
         has_mut_interior: HasMutInterior::in_any_value_of_ty(cx, ty),
         needs_drop: NeedsDrop::in_any_value_of_ty(cx, ty),
         custom_eq: CustomEq::in_any_value_of_ty(cx, ty),
+        error_occured,
     }
 }
 

compiler/rustc_mir/src/transform/check_consts/validation.rs

@@ -123,7 +123,7 @@ impl Qualifs<'mir, 'tcx> {
         has_mut_interior.get().contains(local) || self.indirectly_mutable(ccx, local, location)
     }
 
-    fn in_return_place(&mut self, ccx: &'mir ConstCx<'mir, 'tcx>) -> ConstQualifs {
+    fn in_return_place(&mut self, ccx: &'mir ConstCx<'mir, 'tcx>, error_occured: bool) -> ConstQualifs {
         // Find the `Return` terminator if one exists.
         //
         // If no `Return` terminator exists, this MIR is divergent. Just return the conservative
@@ -139,7 +139,7 @@ impl Qualifs<'mir, 'tcx> {
             .map(|(bb, _)| bb);
 
         let return_block = match return_block {
-            None => return qualifs::in_any_value_of_ty(ccx, ccx.body.return_ty()),
+            None => return qualifs::in_any_value_of_ty(ccx, ccx.body.return_ty(), error_occured),
             Some(bb) => bb,
         };
 
@@ -170,6 +170,7 @@ impl Qualifs<'mir, 'tcx> {
             needs_drop: self.needs_drop(ccx, RETURN_PLACE, return_loc),
             has_mut_interior: self.has_mut_interior(ccx, RETURN_PLACE, return_loc),
             custom_eq,
+            error_occured,
         }
     }
 }
@@ -276,7 +277,7 @@ impl Validator<'mir, 'tcx> {
     }
 
     pub fn qualifs_in_return_place(&mut self) -> ConstQualifs {
-        self.qualifs.in_return_place(self.ccx)
+        self.qualifs.in_return_place(self.ccx, self.error_emitted)
     }
 
     /// Emits an error if an expression cannot be evaluated in the current context.

src/test/ui/consts/issue-76064.rs

@@ -0,0 +1,3 @@
+struct Bug([u8; panic!(1)]); //~ ERROR panicking in constants is unstable
+
+fn main() {}

src/test/ui/consts/issue-76064.stderr

@@ -0,0 +1,13 @@
+error[E0658]: panicking in constants is unstable
+  --> $DIR/issue-76064.rs:1:17
+   |
+LL | struct Bug([u8; panic!(1)]);
+   |                 ^^^^^^^^^
+   |
+   = note: see issue #51999 <https://github.com/rust-lang/rust/issues/51999> for more information
+   = help: add `#![feature(const_panic)]` to the crate attributes to enable
+   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0658`.