Auto merge of rust-lang#129658 - saethlin:spare-a-crumb, r=<try>

Add some track_caller info to precondition panics

r? `@ghost`

Thought of this while looking at rust-lang#129642 (comment)

Author: bors

compiler/rustc_codegen_ssa/src/mir/block.rs

@@ -808,13 +808,15 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                 let (fn_abi, llfn, instance) =
                     common::build_langcall(bx, Some(source_info.span), LangItem::PanicNounwind);
 
+                let location = self.get_caller_location(bx, source_info).immediate();
+
                 // Codegen the actual panic invoke/call.
                 helper.do_call(
                     self,
                     bx,
                     fn_abi,
                     llfn,
-                    &[msg.0, msg.1],
+                    &[msg.0, msg.1, location],
                     target.as_ref().map(|bb| (ReturnDest::Nothing, *bb)),
                     unwind,
                     &[],

compiler/rustc_codegen_ssa/src/size_of_val.rs

@@ -74,12 +74,20 @@ pub fn size_and_align_of_dst<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
             // duplicated plenty of times.)
             let fn_ty = bx.fn_decl_backend_type(fn_abi);
 
+            let const_loc = bx.tcx().span_as_caller_location(rustc_span::DUMMY_SP);
+            let location = crate::mir::operand::OperandRef::from_const(
+                bx,
+                const_loc,
+                bx.tcx().caller_location_ty(),
+            )
+            .immediate();
+
             bx.call(
                 fn_ty,
                 /* fn_attrs */ None,
                 Some(fn_abi),
                 llfn,
-                &[msg.0, msg.1],
+                &[msg.0, msg.1, location],
                 None,
                 None,
             );

library/core/src/alloc/layout.rs

@@ -126,6 +126,7 @@ impl Layout {
     #[rustc_const_stable(feature = "const_alloc_layout_unchecked", since = "1.36.0")]
     #[must_use]
     #[inline]
+    #[track_caller]
     pub const unsafe fn from_size_align_unchecked(size: usize, align: usize) -> Self {
         assert_unsafe_precondition!(
             check_library_ub,

library/core/src/ascii/ascii_char.rs

@@ -503,6 +503,7 @@ impl AsciiChar {
     /// something useful. It might be tightened before stabilization.)
     #[unstable(feature = "ascii_char", issue = "110998")]
     #[inline]
+    #[track_caller]
     pub const unsafe fn digit_unchecked(d: u8) -> Self {
         assert_unsafe_precondition!(
             check_language_ub,

library/core/src/char/convert.rs

@@ -21,6 +21,7 @@ pub(super) const fn from_u32(i: u32) -> Option<char> {
 /// Converts a `u32` to a `char`, ignoring validity. See [`char::from_u32_unchecked`].
 #[inline]
 #[must_use]
+#[track_caller]
 pub(super) const unsafe fn from_u32_unchecked(i: u32) -> char {
     // SAFETY: the caller must guarantee that `i` is a valid char value.
     unsafe {

library/core/src/hint.rs

@@ -97,7 +97,7 @@ use crate::{intrinsics, ub_checks};
 #[inline]
 #[stable(feature = "unreachable", since = "1.27.0")]
 #[rustc_const_stable(feature = "const_unreachable_unchecked", since = "1.57.0")]
-#[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
+#[track_caller]
 pub const unsafe fn unreachable_unchecked() -> ! {
     ub_checks::assert_unsafe_precondition!(
         check_language_ub,

library/core/src/intrinsics/mod.rs

@@ -4407,7 +4407,7 @@ pub const fn ptr_metadata<P: ptr::Pointee<Metadata = M> + ?Sized, M>(_ptr: *cons
 )]
 #[rustc_const_stable(feature = "const_intrinsic_copy", since = "1.83.0")]
 #[inline(always)]
-#[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
+#[track_caller]
 #[rustc_diagnostic_item = "ptr_copy_nonoverlapping"]
 pub const unsafe fn copy_nonoverlapping<T>(src: *const T, dst: *mut T, count: usize) {
     #[rustc_intrinsic_const_stable_indirect]
@@ -4515,7 +4515,7 @@ pub const unsafe fn copy_nonoverlapping<T>(src: *const T, dst: *mut T, count: us
 )]
 #[rustc_const_stable(feature = "const_intrinsic_copy", since = "1.83.0")]
 #[inline(always)]
-#[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
+#[track_caller]
 #[rustc_diagnostic_item = "ptr_copy"]
 pub const unsafe fn copy<T>(src: *const T, dst: *mut T, count: usize) {
     #[rustc_intrinsic_const_stable_indirect]
@@ -4602,7 +4602,7 @@ pub const unsafe fn copy<T>(src: *const T, dst: *mut T, count: usize) {
 )]
 #[rustc_const_stable(feature = "const_ptr_write", since = "1.83.0")]
 #[inline(always)]
-#[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
+#[track_caller]
 #[rustc_diagnostic_item = "ptr_write_bytes"]
 pub const unsafe fn write_bytes<T>(dst: *mut T, val: u8, count: usize) {
     #[rustc_intrinsic_const_stable_indirect]

library/core/src/num/int_macros.rs

@@ -509,7 +509,7 @@ macro_rules! int_impl {
         #[must_use = "this returns the result of the operation, \
                       without modifying the original"]
         #[inline(always)]
-        #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
+        #[track_caller]
         pub const unsafe fn unchecked_add(self, rhs: Self) -> Self {
             assert_unsafe_precondition!(
                 check_language_ub,
@@ -659,7 +659,7 @@ macro_rules! int_impl {
         #[must_use = "this returns the result of the operation, \
                       without modifying the original"]
         #[inline(always)]
-        #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
+        #[track_caller]
         pub const unsafe fn unchecked_sub(self, rhs: Self) -> Self {
             assert_unsafe_precondition!(
                 check_language_ub,
@@ -809,7 +809,7 @@ macro_rules! int_impl {
         #[must_use = "this returns the result of the operation, \
                       without modifying the original"]
         #[inline(always)]
-        #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
+        #[track_caller]
         pub const unsafe fn unchecked_mul(self, rhs: Self) -> Self {
             assert_unsafe_precondition!(
                 check_language_ub,
@@ -1153,7 +1153,7 @@ macro_rules! int_impl {
         #[must_use = "this returns the result of the operation, \
                       without modifying the original"]
         #[inline(always)]
-        #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
+        #[track_caller]
         pub const unsafe fn unchecked_neg(self) -> Self {
             assert_unsafe_precondition!(
                 check_language_ub,
@@ -1281,7 +1281,7 @@ macro_rules! int_impl {
         #[must_use = "this returns the result of the operation, \
                       without modifying the original"]
         #[inline(always)]
-        #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
+        #[track_caller]
         pub const unsafe fn unchecked_shl(self, rhs: u32) -> Self {
             assert_unsafe_precondition!(
                 check_language_ub,
@@ -1402,7 +1402,7 @@ macro_rules! int_impl {
         #[must_use = "this returns the result of the operation, \
                       without modifying the original"]
         #[inline(always)]
-        #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
+        #[track_caller]
         pub const unsafe fn unchecked_shr(self, rhs: u32) -> Self {
             assert_unsafe_precondition!(
                 check_language_ub,

library/core/src/num/nonzero.rs

@@ -385,6 +385,7 @@ where
     #[rustc_const_stable(feature = "nonzero", since = "1.28.0")]
     #[must_use]
     #[inline]
+    #[track_caller]
     pub const unsafe fn new_unchecked(n: T) -> Self {
         match Self::new(n) {
             Some(n) => n,
@@ -425,6 +426,7 @@ where
     #[unstable(feature = "nonzero_from_mut", issue = "106290")]
     #[must_use]
     #[inline]
+    #[track_caller]
     pub unsafe fn from_mut_unchecked(n: &mut T) -> &mut Self {
         match Self::from_mut(n) {
             Some(n) => n,

library/core/src/num/uint_macros.rs

@@ -556,7 +556,7 @@ macro_rules! uint_impl {
         #[must_use = "this returns the result of the operation, \
                       without modifying the original"]
         #[inline(always)]
-        #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
+        #[track_caller]
         pub const unsafe fn unchecked_add(self, rhs: Self) -> Self {
             assert_unsafe_precondition!(
                 check_language_ub,
@@ -746,7 +746,7 @@ macro_rules! uint_impl {
         #[must_use = "this returns the result of the operation, \
                       without modifying the original"]
         #[inline(always)]
-        #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
+        #[track_caller]
         pub const unsafe fn unchecked_sub(self, rhs: Self) -> Self {
             assert_unsafe_precondition!(
                 check_language_ub,
@@ -929,7 +929,7 @@ macro_rules! uint_impl {
         #[must_use = "this returns the result of the operation, \
                       without modifying the original"]
         #[inline(always)]
-        #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
+        #[track_caller]
         pub const unsafe fn unchecked_mul(self, rhs: Self) -> Self {
             assert_unsafe_precondition!(
                 check_language_ub,
@@ -1543,7 +1543,7 @@ macro_rules! uint_impl {
         #[must_use = "this returns the result of the operation, \
                       without modifying the original"]
         #[inline(always)]
-        #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
+        #[track_caller]
         pub const unsafe fn unchecked_shl(self, rhs: u32) -> Self {
             assert_unsafe_precondition!(
                 check_language_ub,
@@ -1664,7 +1664,7 @@ macro_rules! uint_impl {
         #[must_use = "this returns the result of the operation, \
                       without modifying the original"]
         #[inline(always)]
-        #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
+        #[track_caller]
         pub const unsafe fn unchecked_shr(self, rhs: u32) -> Self {
             assert_unsafe_precondition!(
                 check_language_ub,