make InterpResult a dedicated type to avoid accidentally discarding the error

compiler/rustc_const_eval/src/const_eval/eval_queries.rs

@@ -20,7 +20,7 @@ use crate::const_eval::CheckAlignment;
 use crate::interpret::{
     CtfeValidationMode, GlobalId, Immediate, InternKind, InternResult, InterpCx, InterpError,
     InterpResult, MPlaceTy, MemoryKind, OpTy, RefTracking, StackPopCleanup, create_static_alloc,
-    eval_nullary_intrinsic, intern_const_alloc_recursive, throw_exhaust,
+    eval_nullary_intrinsic, intern_const_alloc_recursive, interp_ok, throw_exhaust,
 };
 use crate::{CTRL_C_RECEIVED, errors};
 
@@ -98,19 +98,19 @@ fn eval_body_using_ecx<'tcx, R: InterpretationResult<'tcx>>(
             return Err(ecx
                 .tcx
                 .dcx()
-                .emit_err(errors::DanglingPtrInFinal { span: ecx.tcx.span, kind: intern_kind })
-                .into());
+                .emit_err(errors::DanglingPtrInFinal { span: ecx.tcx.span, kind: intern_kind }))
+            .into();
         }
         Err(InternResult::FoundBadMutablePointer) => {
             return Err(ecx
                 .tcx
                 .dcx()
-                .emit_err(errors::MutablePtrInFinal { span: ecx.tcx.span, kind: intern_kind })
-                .into());
+                .emit_err(errors::MutablePtrInFinal { span: ecx.tcx.span, kind: intern_kind }))
+            .into();
         }
     }
 
-    Ok(R::make_result(ret, ecx))
+    interp_ok(R::make_result(ret, ecx))
 }
 
 /// The `InterpCx` is only meant to be used to do field and index projections into constants for
@@ -147,7 +147,8 @@ pub fn mk_eval_cx_for_const_val<'tcx>(
     ty: Ty<'tcx>,
 ) -> Option<(CompileTimeInterpCx<'tcx>, OpTy<'tcx>)> {
     let ecx = mk_eval_cx_to_read_const_val(tcx.tcx, tcx.span, param_env, CanAccessMutGlobal::No);
-    let op = ecx.const_val_to_op(val, ty, None).ok()?;
+    // FIXME: is it a problem to discard the error here?
+    let op = ecx.const_val_to_op(val, ty, None).discard_err()?;
     Some((ecx, op))
 }
 
@@ -185,12 +186,16 @@ pub(super) fn op_to_const<'tcx>(
         _ => false,
     };
     let immediate = if force_as_immediate {
-        match ecx.read_immediate(op) {
+        match ecx.read_immediate(op).report_err() {
             Ok(imm) => Right(imm),
-            Err(err) if !for_diagnostics => {
-                panic!("normalization works on validated constants: {err:?}")
+            Err(err) => {
+                if for_diagnostics {
+                    // This discard the error, but for diagnostics that's okay.
+                    op.as_mplace_or_imm()
+                } else {
+                    panic!("normalization works on validated constants: {err:?}")
+                }
             }
-            _ => op.as_mplace_or_imm(),
         }
     } else {
         op.as_mplace_or_imm()
@@ -283,17 +288,19 @@ pub fn eval_to_const_value_raw_provider<'tcx>(
         let ty::FnDef(_, args) = ty.kind() else {
             bug!("intrinsic with type {:?}", ty);
         };
-        return eval_nullary_intrinsic(tcx, key.param_env, def_id, args).map_err(|error| {
-            let span = tcx.def_span(def_id);
+        return eval_nullary_intrinsic(tcx, key.param_env, def_id, args).report_err().map_err(
+            |error| {
+                let span = tcx.def_span(def_id);
 
-            super::report(
-                tcx,
-                error.into_kind(),
-                span,
-                || (span, vec![]),
-                |span, _| errors::NullaryIntrinsicError { span },
-            )
-        });
+                super::report(
+                    tcx,
+                    error.into_kind(),
+                    span,
+                    || (span, vec![]),
+                    |span, _| errors::NullaryIntrinsicError { span },
+                )
+            },
+        );
     }
 
     tcx.eval_to_allocation_raw(key).map(|val| turn_into_const_value(tcx, val, key))
@@ -376,6 +383,7 @@ fn eval_in_interpreter<'tcx, R: InterpretationResult<'tcx>>(
     );
     let res = ecx.load_mir(cid.instance.def, cid.promoted);
     res.and_then(|body| eval_body_using_ecx(&mut ecx, cid, body))
+        .report_err()
         .map_err(|error| report_eval_error(&ecx, cid, error))
 }
 
@@ -400,6 +408,7 @@ fn const_validate_mplace<'tcx>(
             }
         };
         ecx.const_validate_operand(&mplace.into(), path, &mut ref_tracking, mode)
+            .report_err()
             // Instead of just reporting the `InterpError` via the usual machinery, we give a more targeted
             // error about the validation failure.
             .map_err(|error| report_validation_error(&ecx, cid, error, alloc_id))?;