add method to get absolute address of a pointer (useful only for Miri)

[rust.git] / compiler / rustc_middle / src / mir / interpret / pointer.rs

diff --git a/compiler/rustc_middle/src/mir/interpret/pointer.rs b/compiler/rustc_middle/src/mir/interpret/pointer.rs
index 7d101046a96b48b67f2fdd65e7f8c434bb15a497..4461f4e0568738deccbc4c32c00b134b8debf47f 100644 (file)
--- a/compiler/rustc_middle/src/mir/interpret/pointer.rs
+++ b/compiler/rustc_middle/src/mir/interpret/pointer.rs
@@ -18,6 +18,11 @@ fn pointer_size(&self) -> Size {
         self.data_layout().pointer_size
     }
 
+    #[inline(always)]
+    fn max_size_of_val(&self) -> Size {
+        Size::from_bytes(self.machine_isize_max())
+    }
+
     #[inline]
     fn machine_usize_max(&self) -> u64 {
         self.pointer_size().unsigned_int_max().try_into().unwrap()
@@ -158,6 +163,9 @@ pub struct Pointer<Tag = AllocId> {
 }
 
 static_assert_size!(Pointer, 16);
+// `Option<Tag>` pointers are also passed around quite a bit
+// (but not stored in permanent machine state).
+static_assert_size!(Pointer<Option<AllocId>>, 16);
 
 // We want the `Debug` output to be readable as it is used by `derive(Debug)` for
 // all the Miri types.
@@ -199,6 +207,16 @@ pub fn into_pointer_or_addr(self) -> Result<Pointer<Tag>, Size> {
             None => Err(self.offset),
         }
     }
+
+    /// Returns the absolute address the pointer points to.
+    /// Only works if Tag::OFFSET_IS_ADDR is true!
+    pub fn addr(self) -> Size
+    where
+        Tag: Provenance,
+    {
+        assert!(Tag::OFFSET_IS_ADDR);
+        self.offset
+    }
 }
 
 impl<Tag> Pointer<Option<Tag>> {