Check for initialization of layout-restricted types

Author: LeSeulArtichaut

compiler/rustc_mir_build/src/check_unsafety.rs

@@ -10,6 +10,8 @@ use rustc_span::def_id::{DefId, LocalDefId};
 use rustc_span::symbol::Symbol;
 use rustc_span::Span;
 
+use std::ops::Bound;
+
 struct UnsafetyVisitor<'a, 'tcx> {
     tcx: TyCtxt<'tcx>,
     thir: &'a Thir<'tcx>,
@@ -174,6 +176,17 @@ impl<'a, 'tcx> Visitor<'a, 'tcx> for UnsafetyVisitor<'a, 'tcx> {
                     self.requires_unsafe(expr.span, DerefOfRawPointer);
                 }
             }
+            ExprKind::Adt {
+                adt_def,
+                variant_index: _,
+                substs: _,
+                user_ty: _,
+                fields: _,
+                base: _,
+            } => match self.tcx.layout_scalar_valid_range(adt_def.did) {
+                (Bound::Unbounded, Bound::Unbounded) => {}
+                _ => self.requires_unsafe(expr.span, InitializingTypeWith),
+            },
             _ => {}
         }
 
@@ -216,7 +229,6 @@ impl BodyUnsafety {
 enum UnsafeOpKind {
     CallToUnsafeFunction,
     UseOfInlineAssembly,
-    #[allow(dead_code)] // FIXME
     InitializingTypeWith,
     #[allow(dead_code)] // FIXME
     CastOfPointerToInt,

src/test/ui/unsafe/ranged_ints.stderr renamed to src/test/ui/unsafe/ranged_ints.mir.stderr

@@ -1,5 +1,5 @@
 error[E0133]: initializing type with `rustc_layout_scalar_valid_range` attr is unsafe and requires unsafe function or block
-  --> $DIR/ranged_ints.rs:7:14
+  --> $DIR/ranged_ints.rs:10:14
    |
 LL |     let _x = NonZero(0);
    |              ^^^^^^^^^^ initializing type with `rustc_layout_scalar_valid_range` attr

src/test/ui/unsafe/ranged_ints.rs

@@ -1,3 +1,6 @@
+// revisions: mir thir
+// [thir]compile-flags: -Z thir-unsafeck
+
 #![feature(rustc_attrs)]
 
 #[rustc_layout_scalar_valid_range_start(1)]

src/test/ui/unsafe/ranged_ints.thir.stderr

@@ -0,0 +1,11 @@
+error[E0133]: initializing type with `rustc_layout_scalar_valid_range` attr is unsafe and requires unsafe function or block
+  --> $DIR/ranged_ints.rs:10:14
+   |
+LL |     let _x = NonZero(0);
+   |              ^^^^^^^^^^ initializing type with `rustc_layout_scalar_valid_range` attr
+   |
+   = note: initializing a layout restricted type's field with a value outside the valid range is undefined behavior
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0133`.

src/test/ui/unsafe/ranged_ints_const.stderr renamed to src/test/ui/unsafe/ranged_ints_const.mir.stderr

@@ -1,5 +1,5 @@
 error[E0133]: initializing type with `rustc_layout_scalar_valid_range` attr is unsafe and requires unsafe function or block
-  --> $DIR/ranged_ints_const.rs:8:34
+  --> $DIR/ranged_ints_const.rs:11:34
    |
 LL | const fn foo() -> NonZero<u32> { NonZero(0) }
    |                                  ^^^^^^^^^^ initializing type with `rustc_layout_scalar_valid_range` attr

src/test/ui/unsafe/ranged_ints_const.rs

@@ -1,3 +1,6 @@
+// revisions: mir thir
+// [thir]compile-flags: -Z thir-unsafeck
+
 #![feature(rustc_attrs)]
 
 #[rustc_layout_scalar_valid_range_start(1)]

src/test/ui/unsafe/ranged_ints_const.thir.stderr

@@ -0,0 +1,11 @@
+error[E0133]: initializing type with `rustc_layout_scalar_valid_range` attr is unsafe and requires unsafe function or block
+  --> $DIR/ranged_ints_const.rs:11:34
+   |
+LL | const fn foo() -> NonZero<u32> { NonZero(0) }
+   |                                  ^^^^^^^^^^ initializing type with `rustc_layout_scalar_valid_range` attr
+   |
+   = note: initializing a layout restricted type's field with a value outside the valid range is undefined behavior
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0133`.

src/test/ui/unsafe/ranged_ints_macro.rs

@@ -1,4 +1,7 @@
 // build-pass
+// revisions: mir thir
+// [thir]compile-flags: -Z thir-unsafeck
+
 #![feature(rustc_attrs)]
 
 macro_rules! apply {