Simplify some cfging, fix error msg and comments

Author: compiler-errors

compiler/rustc_middle/src/ty/consts.rs

@@ -135,6 +135,7 @@ impl<'tcx> Const<'tcx> {
         uv: ty::UnevaluatedConst<'tcx>,
         ty: Ty<'tcx>,
     ) -> Const<'tcx> {
+        tcx.debug_assert_args_compatible(uv.def, uv.args);
         Const::new(tcx, ty::ConstKind::Unevaluated(uv), ty)
     }
 

compiler/rustc_middle/src/ty/context.rs

@@ -2009,34 +2009,50 @@ impl<'tcx> TyCtxt<'tcx> {
         true
     }
 
-    pub fn assert_args_compatible(self, def_id: DefId, args: &'tcx [ty::GenericArg<'tcx>]) {
-        if !self.check_args_compatible(def_id, args) {
-            if let DefKind::AssocTy = self.def_kind(def_id)
-                && let DefKind::Impl { of_trait: false } = self.def_kind(self.parent(def_id))
-            {
-                bug!()
-            } else {
-                bug!(
-                    "args not compatible with generics for {}: args={:#?}, generics={:#?}",
-                    self.def_path_str(def_id),
-                    args,
-                    ty::GenericArgs::identity_for_item(self, def_id)
-                );
+    /// With `cfg(debug_assertions)`, assert that args are compatible with their generics,
+    /// and print out the args if not.
+    #[cfg_attr(not(debug_assertions), allow(unused_variables))]
+    pub fn debug_assert_args_compatible(self, def_id: DefId, args: &'tcx [ty::GenericArg<'tcx>]) {
+        #[cfg(debug_assertions)]
+        {
+            if !self.check_args_compatible(def_id, args) {
+                if let DefKind::AssocTy = self.def_kind(def_id)
+                    && let DefKind::Impl { of_trait: false } = self.def_kind(self.parent(def_id))
+                {
+                    bug!(
+                        "args not compatible with generics for {}: args={:#?}, generics={:#?}",
+                        self.def_path_str(def_id),
+                        args,
+                        // Make `[Self, GAT_ARGS...]` (this could be simplified)
+                        self.mk_args_from_iter(
+                            [self.types.self_param.into()].into_iter().chain(
+                                self.generics_of(def_id)
+                                    .own_args(ty::GenericArgs::identity_for_item(self, def_id))
+                                    .iter()
+                                    .copied()
+                            )
+                        )
+                    );
+                } else {
+                    bug!(
+                        "args not compatible with generics for {}: args={:#?}, generics={:#?}",
+                        self.def_path_str(def_id),
+                        args,
+                        ty::GenericArgs::identity_for_item(self, def_id)
+                    );
+                }
             }
         }
     }
 
     #[inline(always)]
     pub(crate) fn check_and_mk_args(
         self,
-        _def_id: DefId,
+        def_id: DefId,
         args: impl IntoIterator<Item: Into<GenericArg<'tcx>>>,
     ) -> GenericArgsRef<'tcx> {
         let args = self.mk_args_from_iter(args.into_iter().map(Into::into));
-        #[cfg(debug_assertions)]
-        {
-            self.assert_args_compatible(_def_id, args);
-        }
+        self.debug_assert_args_compatible(def_id, args);
         args
     }
 

compiler/rustc_middle/src/ty/sty.rs

@@ -1624,9 +1624,7 @@ impl<'tcx> Ty<'tcx> {
 
     #[inline]
     pub fn new_adt(tcx: TyCtxt<'tcx>, def: AdtDef<'tcx>, args: GenericArgsRef<'tcx>) -> Ty<'tcx> {
-        if cfg!(debug_assertions) {
-            tcx.assert_args_compatible(def.did(), args);
-        }
+        tcx.debug_assert_args_compatible(def.did(), args);
         Ty::new(tcx, Adt(def, args))
     }
 
@@ -1707,9 +1705,7 @@ impl<'tcx> Ty<'tcx> {
         def_id: DefId,
         closure_args: GenericArgsRef<'tcx>,
     ) -> Ty<'tcx> {
-        if cfg!(debug_assertions) {
-            tcx.assert_args_compatible(def_id, closure_args);
-        }
+        tcx.debug_assert_args_compatible(def_id, closure_args);
         Ty::new(tcx, Closure(def_id, closure_args))
     }
 
@@ -1719,9 +1715,7 @@ impl<'tcx> Ty<'tcx> {
         def_id: DefId,
         closure_args: GenericArgsRef<'tcx>,
     ) -> Ty<'tcx> {
-        if cfg!(debug_assertions) {
-            tcx.assert_args_compatible(def_id, closure_args);
-        }
+        tcx.debug_assert_args_compatible(def_id, closure_args);
         Ty::new(tcx, CoroutineClosure(def_id, closure_args))
     }
 
@@ -1731,9 +1725,7 @@ impl<'tcx> Ty<'tcx> {
         def_id: DefId,
         coroutine_args: GenericArgsRef<'tcx>,
     ) -> Ty<'tcx> {
-        if cfg!(debug_assertions) {
-            tcx.assert_args_compatible(def_id, coroutine_args);
-        }
+        tcx.debug_assert_args_compatible(def_id, coroutine_args);
         Ty::new(tcx, Coroutine(def_id, coroutine_args))
     }