Constify intrinsics::copy[_nonoverlapping]

[rust.git] / compiler / rustc_mir / src / interpret / intrinsics.rs

diff --git a/compiler/rustc_mir/src/interpret/intrinsics.rs b/compiler/rustc_mir/src/interpret/intrinsics.rs
index 474e1f8e577f8b647be644be217823779244fd31..c182fa35ee24affbcc8ddf7a472e577c96b00521 100644 (file)
--- a/compiler/rustc_mir/src/interpret/intrinsics.rs
+++ b/compiler/rustc_mir/src/interpret/intrinsics.rs
@@ -322,6 +322,29 @@ pub fn emulate_intrinsic(
                 let result = Scalar::from_uint(truncated_bits, layout.size);
                 self.write_scalar(result, dest)?;
             }
+            sym::copy | sym::copy_nonoverlapping => {
+                let elem_ty = instance.substs.type_at(0);
+                let elem_layout = self.layout_of(elem_ty)?;
+                let count = self.read_scalar(args[2])?.to_machine_usize(self)?;
+                let elem_align = elem_layout.align.abi;
+
+                let size = elem_layout.size.checked_mul(count, self).ok_or_else(|| {
+                    err_ub_format!("overflow computing total size of `{}`", intrinsic_name)
+                })?;
+                let src = self.read_scalar(args[0])?.check_init()?;
+                let src = self.memory.check_ptr_access(src, size, elem_align)?;
+                let dest = self.read_scalar(args[1])?.check_init()?;
+                let dest = self.memory.check_ptr_access(dest, size, elem_align)?;
+
+                if let (Some(src), Some(dest)) = (src, dest) {
+                    self.memory.copy(
+                        src,
+                        dest,
+                        size,
+                        intrinsic_name == sym::copy_nonoverlapping,
+                    )?;
+                }
+            }
             sym::offset => {
                 let ptr = self.read_scalar(args[0])?.check_init()?;
                 let offset_count = self.read_scalar(args[1])?.to_machine_isize(self)?;