From 13877a965d93100b5995da612a95612919a45cfa Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Wed, 20 Jul 2022 16:42:20 -0400
Subject: [PATCH] prune raw pointer read and write methods from Miri backtraces

---
 library/core/src/intrinsics.rs    | 1 +
 library/core/src/ptr/const_ptr.rs | 3 +++
 library/core/src/ptr/mod.rs       | 6 ++++++
 library/core/src/ptr/mut_ptr.rs   | 7 +++++++
 4 files changed, 17 insertions(+)

diff --git a/library/core/src/intrinsics.rs b/library/core/src/intrinsics.rs
index 998f7be3f7396..32fb0f82f1010 100644
--- a/library/core/src/intrinsics.rs
+++ b/library/core/src/intrinsics.rs
@@ -2615,6 +2615,7 @@ pub const unsafe fn copy<T>(src: *const T, dst: *mut T, count: usize) {
 #[cfg_attr(not(bootstrap), rustc_allowed_through_unstable_modules)]
 #[rustc_const_unstable(feature = "const_ptr_write", issue = "86302")]
 #[inline]
+#[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
 pub const unsafe fn write_bytes<T>(dst: *mut T, val: u8, count: usize) {
     extern "rust-intrinsic" {
         #[rustc_const_unstable(feature = "const_ptr_write", issue = "86302")]
diff --git a/library/core/src/ptr/const_ptr.rs b/library/core/src/ptr/const_ptr.rs
index 74aa0d9c7bcb2..b961d875c0eb6 100644
--- a/library/core/src/ptr/const_ptr.rs
+++ b/library/core/src/ptr/const_ptr.rs
@@ -1144,6 +1144,7 @@ impl<T: ?Sized> *const T {
     #[stable(feature = "pointer_methods", since = "1.26.0")]
     #[rustc_const_unstable(feature = "const_ptr_read", issue = "80377")]
     #[inline]
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
     pub const unsafe fn read(self) -> T
     where
         T: Sized,
@@ -1164,6 +1165,7 @@ impl<T: ?Sized> *const T {
     /// [`ptr::read_volatile`]: crate::ptr::read_volatile()
     #[stable(feature = "pointer_methods", since = "1.26.0")]
     #[inline]
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
     pub unsafe fn read_volatile(self) -> T
     where
         T: Sized,
@@ -1183,6 +1185,7 @@ impl<T: ?Sized> *const T {
     #[stable(feature = "pointer_methods", since = "1.26.0")]
     #[rustc_const_unstable(feature = "const_ptr_read", issue = "80377")]
     #[inline]
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
     pub const unsafe fn read_unaligned(self) -> T
     where
         T: Sized,
diff --git a/library/core/src/ptr/mod.rs b/library/core/src/ptr/mod.rs
index 62548b5fadd2e..40e28e636d851 100644
--- a/library/core/src/ptr/mod.rs
+++ b/library/core/src/ptr/mod.rs
@@ -1095,6 +1095,7 @@ pub const unsafe fn replace<T>(dst: *mut T, mut src: T) -> T {
 #[inline]
 #[stable(feature = "rust1", since = "1.0.0")]
 #[rustc_const_unstable(feature = "const_ptr_read", issue = "80377")]
+#[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
 pub const unsafe fn read<T>(src: *const T) -> T {
     // We are calling the intrinsics directly to avoid function calls in the generated code
     // as `intrinsics::copy_nonoverlapping` is a wrapper function.
@@ -1194,6 +1195,7 @@ pub const unsafe fn read<T>(src: *const T) -> T {
 #[inline]
 #[stable(feature = "ptr_unaligned", since = "1.17.0")]
 #[rustc_const_unstable(feature = "const_ptr_read", issue = "80377")]
+#[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
 pub const unsafe fn read_unaligned<T>(src: *const T) -> T {
     let mut tmp = MaybeUninit::<T>::uninit();
     // SAFETY: the caller must guarantee that `src` is valid for reads.
@@ -1290,6 +1292,7 @@ pub const unsafe fn read_unaligned<T>(src: *const T) -> T {
 #[inline]
 #[stable(feature = "rust1", since = "1.0.0")]
 #[rustc_const_unstable(feature = "const_ptr_write", issue = "86302")]
+#[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
 pub const unsafe fn write<T>(dst: *mut T, src: T) {
     // We are calling the intrinsics directly to avoid function calls in the generated code
     // as `intrinsics::copy_nonoverlapping` is a wrapper function.
@@ -1387,6 +1390,7 @@ pub const unsafe fn write<T>(dst: *mut T, src: T) {
 #[inline]
 #[stable(feature = "ptr_unaligned", since = "1.17.0")]
 #[rustc_const_unstable(feature = "const_ptr_write", issue = "86302")]
+#[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
 pub const unsafe fn write_unaligned<T>(dst: *mut T, src: T) {
     // SAFETY: the caller must guarantee that `dst` is valid for writes.
     // `dst` cannot overlap `src` because the caller has mutable access
@@ -1460,6 +1464,7 @@ pub const unsafe fn write_unaligned<T>(dst: *mut T, src: T) {
 /// ```
 #[inline]
 #[stable(feature = "volatile", since = "1.9.0")]
+#[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
 pub unsafe fn read_volatile<T>(src: *const T) -> T {
     // SAFETY: the caller must uphold the safety contract for `volatile_load`.
     unsafe {
@@ -1530,6 +1535,7 @@ pub unsafe fn read_volatile<T>(src: *const T) -> T {
 /// ```
 #[inline]
 #[stable(feature = "volatile", since = "1.9.0")]
+#[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
 pub unsafe fn write_volatile<T>(dst: *mut T, src: T) {
     // SAFETY: the caller must uphold the safety contract for `volatile_store`.
     unsafe {
diff --git a/library/core/src/ptr/mut_ptr.rs b/library/core/src/ptr/mut_ptr.rs
index b988090f4bc4c..21dc191191816 100644
--- a/library/core/src/ptr/mut_ptr.rs
+++ b/library/core/src/ptr/mut_ptr.rs
@@ -1256,6 +1256,7 @@ impl<T: ?Sized> *mut T {
     #[stable(feature = "pointer_methods", since = "1.26.0")]
     #[rustc_const_unstable(feature = "const_ptr_read", issue = "80377")]
     #[inline(always)]
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
     pub const unsafe fn read(self) -> T
     where
         T: Sized,
@@ -1276,6 +1277,7 @@ impl<T: ?Sized> *mut T {
     /// [`ptr::read_volatile`]: crate::ptr::read_volatile()
     #[stable(feature = "pointer_methods", since = "1.26.0")]
     #[inline(always)]
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
     pub unsafe fn read_volatile(self) -> T
     where
         T: Sized,
@@ -1295,6 +1297,7 @@ impl<T: ?Sized> *mut T {
     #[stable(feature = "pointer_methods", since = "1.26.0")]
     #[rustc_const_unstable(feature = "const_ptr_read", issue = "80377")]
     #[inline(always)]
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
     pub const unsafe fn read_unaligned(self) -> T
     where
         T: Sized,
@@ -1400,6 +1403,7 @@ impl<T: ?Sized> *mut T {
     #[stable(feature = "pointer_methods", since = "1.26.0")]
     #[rustc_const_unstable(feature = "const_ptr_write", issue = "86302")]
     #[inline(always)]
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
     pub const unsafe fn write(self, val: T)
     where
         T: Sized,
@@ -1418,6 +1422,7 @@ impl<T: ?Sized> *mut T {
     #[stable(feature = "pointer_methods", since = "1.26.0")]
     #[rustc_const_unstable(feature = "const_ptr_write", issue = "86302")]
     #[inline(always)]
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
     pub const unsafe fn write_bytes(self, val: u8, count: usize)
     where
         T: Sized,
@@ -1438,6 +1443,7 @@ impl<T: ?Sized> *mut T {
     /// [`ptr::write_volatile`]: crate::ptr::write_volatile()
     #[stable(feature = "pointer_methods", since = "1.26.0")]
     #[inline(always)]
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
     pub unsafe fn write_volatile(self, val: T)
     where
         T: Sized,
@@ -1457,6 +1463,7 @@ impl<T: ?Sized> *mut T {
     #[stable(feature = "pointer_methods", since = "1.26.0")]
     #[rustc_const_unstable(feature = "const_ptr_write", issue = "86302")]
     #[inline(always)]
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
     pub const unsafe fn write_unaligned(self, val: T)
     where
         T: Sized,