Auto merge of #127995 - workingjubilee:say-turings-prayer, r=BoxyUwU

compiler: Never debug_assert in codegen

In the name of Turing and his Hoarey heralds, assert our truths before creating a monster!

The `rustc_codegen_llvm` and `rustc_codegen_ssa` crates are fairly critical for rustc's correctness. Small mistakes here can easily result in undefined behavior, since a "small mistake" can mean something like "link and execute the wrong code". We should probably run any and all asserts in these modules unconditionally on whether this is a "debug build", and damn the costs in performance.

...Especially because the costs in performance seem to be *nothing*. It is not clear how much correctness we gain here, but I'll take free correctness improvements.

compiler/rustc_codegen_llvm/src/consts.rs

@@ -330,7 +330,7 @@ impl<'ll> CodegenCx<'ll, '_> {
 
             // If this assertion triggers, there's something wrong with commandline
             // argument validation.
-            debug_assert!(
+            assert!(
                 !(self.tcx.sess.opts.cg.linker_plugin_lto.enabled()
                     && self.tcx.sess.target.is_like_windows
                     && self.tcx.sess.opts.cg.prefer_dynamic)

compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs

@@ -170,7 +170,7 @@ fn build_pointer_or_reference_di_node<'ll, 'tcx>(
 ) -> DINodeCreationResult<'ll> {
     // The debuginfo generated by this function is only valid if `ptr_type` is really just
     // a (fat) pointer. Make sure it is not called for e.g. `Box<T, NonZSTAllocator>`.
-    debug_assert_eq!(
+    assert_eq!(
         cx.size_and_align_of(ptr_type),
         cx.size_and_align_of(Ty::new_mut_ptr(cx.tcx, pointee_type))
     );
@@ -185,7 +185,7 @@ fn build_pointer_or_reference_di_node<'ll, 'tcx>(
     match fat_pointer_kind(cx, pointee_type) {
         None => {
             // This is a thin pointer. Create a regular pointer type and give it the correct name.
-            debug_assert_eq!(
+            assert_eq!(
                 (data_layout.pointer_size, data_layout.pointer_align.abi),
                 cx.size_and_align_of(ptr_type),
                 "ptr_type={ptr_type}, pointee_type={pointee_type}",
@@ -240,8 +240,8 @@ fn build_pointer_or_reference_di_node<'ll, 'tcx>(
                         FatPtrKind::Slice => ("data_ptr", "length"),
                     };
 
-                    debug_assert_eq!(abi::FAT_PTR_ADDR, 0);
-                    debug_assert_eq!(abi::FAT_PTR_EXTRA, 1);
+                    assert_eq!(abi::FAT_PTR_ADDR, 0);
+                    assert_eq!(abi::FAT_PTR_EXTRA, 1);
 
                     // The data pointer type is a regular, thin pointer, regardless of whether this
                     // is a slice or a trait object.
@@ -498,7 +498,7 @@ pub fn type_di_node<'ll, 'tcx>(cx: &CodegenCx<'ll, 'tcx>, t: Ty<'tcx>) -> &'ll D
                     }
                 };
 
-            debug_assert_eq!(di_node_for_uid as *const _, di_node as *const _);
+            assert_eq!(di_node_for_uid as *const _, di_node as *const _);
         } else {
             debug_context(cx).type_map.insert(unique_type_id, di_node);
         }
@@ -1060,7 +1060,7 @@ fn build_struct_type_di_node<'ll, 'tcx>(
     let ty::Adt(adt_def, _) = struct_type.kind() else {
         bug!("build_struct_type_di_node() called with non-struct-type: {:?}", struct_type);
     };
-    debug_assert!(adt_def.is_struct());
+    assert!(adt_def.is_struct());
     let containing_scope = get_namespace_for_item(cx, adt_def.did());
     let struct_type_and_layout = cx.layout_of(struct_type);
     let variant_def = adt_def.non_enum_variant();
@@ -1130,7 +1130,7 @@ fn build_upvar_field_di_nodes<'ll, 'tcx>(
         }
     };
 
-    debug_assert!(
+    assert!(
         up_var_tys.iter().all(|t| t == cx.tcx.normalize_erasing_regions(ParamEnv::reveal_all(), t))
     );
 

compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/cpp_like.rs

@@ -204,7 +204,7 @@ pub(super) fn build_enum_type_di_node<'ll, 'tcx>(
     let enum_type_and_layout = cx.layout_of(enum_type);
     let enum_type_name = compute_debuginfo_type_name(cx.tcx, enum_type, false);
 
-    debug_assert!(!wants_c_like_enum_debuginfo(enum_type_and_layout));
+    assert!(!wants_c_like_enum_debuginfo(enum_type_and_layout));
 
     type_map::build_type_with_children(
         cx,
@@ -279,7 +279,7 @@ pub(super) fn build_coroutine_di_node<'ll, 'tcx>(
     let coroutine_type_and_layout = cx.layout_of(coroutine_type);
     let coroutine_type_name = compute_debuginfo_type_name(cx.tcx, coroutine_type, false);
 
-    debug_assert!(!wants_c_like_enum_debuginfo(coroutine_type_and_layout));
+    assert!(!wants_c_like_enum_debuginfo(coroutine_type_and_layout));
 
     type_map::build_type_with_children(
         cx,
@@ -517,7 +517,7 @@ fn build_variant_struct_wrapper_type_di_node<'ll, 'tcx>(
                     if is_128_bits {
                         DiscrKind::Exact128(discr_val)
                     } else {
-                        debug_assert_eq!(discr_val, discr_val as u64 as u128);
+                        assert_eq!(discr_val, discr_val as u64 as u128);
                         DiscrKind::Exact(discr_val as u64)
                     }
                 }
@@ -526,8 +526,8 @@ fn build_variant_struct_wrapper_type_di_node<'ll, 'tcx>(
                     if is_128_bits {
                         DiscrKind::Range128(min, max)
                     } else {
-                        debug_assert_eq!(min, min as u64 as u128);
-                        debug_assert_eq!(max, max as u64 as u128);
+                        assert_eq!(min, min as u64 as u128);
+                        assert_eq!(max, max as u64 as u128);
                         DiscrKind::Range(min as u64, max as u64)
                     }
                 }
@@ -815,7 +815,7 @@ fn build_union_fields_for_direct_tag_enum_or_coroutine<'ll, 'tcx>(
         }
     }));
 
-    debug_assert_eq!(
+    assert_eq!(
         cx.size_and_align_of(enum_type_and_layout.field(cx, tag_field).ty),
         cx.size_and_align_of(super::tag_base_type(cx, enum_type_and_layout))
     );

compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/mod.rs

@@ -106,7 +106,7 @@ fn tag_base_type<'ll, 'tcx>(
     cx: &CodegenCx<'ll, 'tcx>,
     enum_type_and_layout: TyAndLayout<'tcx>,
 ) -> Ty<'tcx> {
-    debug_assert!(match enum_type_and_layout.ty.kind() {
+    assert!(match enum_type_and_layout.ty.kind() {
         ty::Coroutine(..) => true,
         ty::Adt(adt_def, _) => adt_def.is_enum(),
         _ => false,
@@ -251,7 +251,7 @@ fn build_enum_variant_struct_type_di_node<'ll, 'tcx>(
     variant_layout: TyAndLayout<'tcx>,
     di_flags: DIFlags,
 ) -> &'ll DIType {
-    debug_assert_eq!(variant_layout.ty, enum_type_and_layout.ty);
+    assert_eq!(variant_layout.ty, enum_type_and_layout.ty);
 
     type_map::build_type_with_children(
         cx,

compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/native.rs

@@ -65,7 +65,7 @@ pub(super) fn build_enum_type_di_node<'ll, 'tcx>(
 
     let visibility_flags = visibility_di_flags(cx, enum_adt_def.did(), enum_adt_def.did());
 
-    debug_assert!(!wants_c_like_enum_debuginfo(enum_type_and_layout));
+    assert!(!wants_c_like_enum_debuginfo(enum_type_and_layout));
 
     type_map::build_type_with_children(
         cx,
@@ -142,7 +142,7 @@ pub(super) fn build_coroutine_di_node<'ll, 'tcx>(
     let containing_scope = get_namespace_for_item(cx, coroutine_def_id);
     let coroutine_type_and_layout = cx.layout_of(coroutine_type);
 
-    debug_assert!(!wants_c_like_enum_debuginfo(coroutine_type_and_layout));
+    assert!(!wants_c_like_enum_debuginfo(coroutine_type_and_layout));
 
     let coroutine_type_name = compute_debuginfo_type_name(cx.tcx, coroutine_type, false);
 

compiler/rustc_codegen_llvm/src/debuginfo/metadata/type_map.rs

@@ -36,7 +36,7 @@ mod private {
 
 /// A unique identifier for anything that we create a debuginfo node for.
 /// The types it contains are expected to already be normalized (which
-/// is debug_asserted in the constructors).
+/// is asserted in the constructors).
 ///
 /// Note that there are some things that only show up in debuginfo, like
 /// the separate type descriptions for each enum variant. These get an ID
@@ -58,12 +58,12 @@ pub(super) enum UniqueTypeId<'tcx> {
 
 impl<'tcx> UniqueTypeId<'tcx> {
     pub fn for_ty(tcx: TyCtxt<'tcx>, t: Ty<'tcx>) -> Self {
-        debug_assert_eq!(t, tcx.normalize_erasing_regions(ParamEnv::reveal_all(), t));
+        assert_eq!(t, tcx.normalize_erasing_regions(ParamEnv::reveal_all(), t));
         UniqueTypeId::Ty(t, private::HiddenZst)
     }
 
     pub fn for_enum_variant_part(tcx: TyCtxt<'tcx>, enum_ty: Ty<'tcx>) -> Self {
-        debug_assert_eq!(enum_ty, tcx.normalize_erasing_regions(ParamEnv::reveal_all(), enum_ty));
+        assert_eq!(enum_ty, tcx.normalize_erasing_regions(ParamEnv::reveal_all(), enum_ty));
         UniqueTypeId::VariantPart(enum_ty, private::HiddenZst)
     }
 
@@ -72,7 +72,7 @@ impl<'tcx> UniqueTypeId<'tcx> {
         enum_ty: Ty<'tcx>,
         variant_idx: VariantIdx,
     ) -> Self {
-        debug_assert_eq!(enum_ty, tcx.normalize_erasing_regions(ParamEnv::reveal_all(), enum_ty));
+        assert_eq!(enum_ty, tcx.normalize_erasing_regions(ParamEnv::reveal_all(), enum_ty));
         UniqueTypeId::VariantStructType(enum_ty, variant_idx, private::HiddenZst)
     }
 
@@ -81,7 +81,7 @@ impl<'tcx> UniqueTypeId<'tcx> {
         enum_ty: Ty<'tcx>,
         variant_idx: VariantIdx,
     ) -> Self {
-        debug_assert_eq!(enum_ty, tcx.normalize_erasing_regions(ParamEnv::reveal_all(), enum_ty));
+        assert_eq!(enum_ty, tcx.normalize_erasing_regions(ParamEnv::reveal_all(), enum_ty));
         UniqueTypeId::VariantStructTypeCppLikeWrapper(enum_ty, variant_idx, private::HiddenZst)
     }
 
@@ -90,11 +90,8 @@ impl<'tcx> UniqueTypeId<'tcx> {
         self_type: Ty<'tcx>,
         implemented_trait: Option<PolyExistentialTraitRef<'tcx>>,
     ) -> Self {
-        debug_assert_eq!(
-            self_type,
-            tcx.normalize_erasing_regions(ParamEnv::reveal_all(), self_type)
-        );
-        debug_assert_eq!(
+        assert_eq!(self_type, tcx.normalize_erasing_regions(ParamEnv::reveal_all(), self_type));
+        assert_eq!(
             implemented_trait,
             tcx.normalize_erasing_regions(ParamEnv::reveal_all(), implemented_trait)
         );
@@ -252,10 +249,7 @@ pub(super) fn build_type_with_children<'ll, 'tcx>(
     members: impl FnOnce(&CodegenCx<'ll, 'tcx>, &'ll DIType) -> SmallVec<&'ll DIType>,
     generics: impl FnOnce(&CodegenCx<'ll, 'tcx>) -> SmallVec<&'ll DIType>,
 ) -> DINodeCreationResult<'ll> {
-    debug_assert_eq!(
-        debug_context(cx).type_map.di_node_for_unique_id(stub_info.unique_type_id),
-        None
-    );
+    assert_eq!(debug_context(cx).type_map.di_node_for_unique_id(stub_info.unique_type_id), None);
 
     debug_context(cx).type_map.insert(stub_info.unique_type_id, stub_info.metadata);
 

compiler/rustc_codegen_llvm/src/debuginfo/utils.rs

@@ -81,7 +81,7 @@ pub(crate) fn fat_pointer_kind<'ll, 'tcx>(
         ty::Dynamic(..) => Some(FatPtrKind::Dyn),
         ty::Foreign(_) => {
             // Assert that pointers to foreign types really are thin:
-            debug_assert_eq!(
+            assert_eq!(
                 cx.size_of(Ty::new_imm_ptr(cx.tcx, pointee_tail_ty)),
                 cx.size_of(Ty::new_imm_ptr(cx.tcx, cx.tcx.types.u8))
             );