Rollup merge of #98979 - RalfJung:more-alloc-range, r=oli-obk

interpret: use AllocRange in UninitByteAccess

also use nice new format string syntax in `interpret/error.rs`, and use the `#` flag to add `0x` prefixes where applicable.

r? ``@oli-obk``

compiler/rustc_const_eval/src/interpret/validity.rs

@@ -427,7 +427,7 @@ impl<'rt, 'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> ValidityVisitor<'rt, 'mir, '
             err_ub!(DanglingIntPointer(0, _)) =>
                 { "a null {kind}" },
             err_ub!(DanglingIntPointer(i, _)) =>
-                { "a dangling {kind} (address 0x{i:x} is unallocated)" },
+                { "a dangling {kind} (address {i:#x} is unallocated)" },
             err_ub!(PointerOutOfBounds { .. }) =>
                 { "a dangling {kind} (going beyond the bounds of its allocation)" },
             // This cannot happen during const-eval (because interning already detects
@@ -941,7 +941,7 @@ impl<'rt, 'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> ValueVisitor<'mir, 'tcx, M>
                                 // element that byte belongs to so we can
                                 // provide an index.
                                 let i = usize::try_from(
-                                    access.uninit_offset.bytes() / layout.size.bytes(),
+                                    access.uninit.start.bytes() / layout.size.bytes(),
                                 )
                                 .unwrap();
                                 self.path.push(PathElem::ArrayElem(i));

compiler/rustc_middle/src/mir/interpret/allocation.rs

@@ -179,6 +179,11 @@ pub fn alloc_range(start: Size, size: Size) -> AllocRange {
 }
 
 impl AllocRange {
+    #[inline]
+    pub fn from(r: Range<Size>) -> Self {
+        alloc_range(r.start, r.end - r.start) // `Size` subtraction (overflow-checked)
+    }
+
     #[inline(always)]
     pub fn end(self) -> Size {
         self.start + self.size // This does overflow checking.
@@ -1095,17 +1100,17 @@ impl InitMask {
     /// Returns `Ok(())` if it's initialized. Otherwise returns a range of byte
     /// indexes for the first contiguous span of the uninitialized access.
     #[inline]
-    pub fn is_range_initialized(&self, start: Size, end: Size) -> Result<(), Range<Size>> {
+    pub fn is_range_initialized(&self, start: Size, end: Size) -> Result<(), AllocRange> {
         if end > self.len {
-            return Err(self.len..end);
+            return Err(AllocRange::from(self.len..end));
         }
 
         let uninit_start = self.find_bit(start, end, false);
 
         match uninit_start {
             Some(uninit_start) => {
                 let uninit_end = self.find_bit(uninit_start, end, true).unwrap_or(end);
-                Err(uninit_start..uninit_end)
+                Err(AllocRange::from(uninit_start..uninit_end))
             }
             None => Ok(()),
         }
@@ -1176,19 +1181,17 @@ impl<Tag: Copy, Extra> Allocation<Tag, Extra> {
     ///
     /// Returns `Ok(())` if it's initialized. Otherwise returns the range of byte
     /// indexes of the first contiguous uninitialized access.
-    fn is_init(&self, range: AllocRange) -> Result<(), Range<Size>> {
+    fn is_init(&self, range: AllocRange) -> Result<(), AllocRange> {
         self.init_mask.is_range_initialized(range.start, range.end()) // `Size` addition
     }
 
     /// Checks that a range of bytes is initialized. If not, returns the `InvalidUninitBytes`
     /// error which will report the first range of bytes which is uninitialized.
     fn check_init(&self, range: AllocRange) -> AllocResult {
-        self.is_init(range).map_err(|idx_range| {
+        self.is_init(range).map_err(|uninit_range| {
             AllocError::InvalidUninitBytes(Some(UninitBytesAccess {
-                access_offset: range.start,
-                access_size: range.size,
-                uninit_offset: idx_range.start,
-                uninit_size: idx_range.end - idx_range.start, // `Size` subtraction
+                access: range,
+                uninit: uninit_range,
             }))
         })
     }

compiler/rustc_middle/src/mir/interpret/error.rs

@@ -1,4 +1,4 @@
-use super::{AllocId, ConstAlloc, Pointer, Scalar};
+use super::{AllocId, AllocRange, ConstAlloc, Pointer, Scalar};
 
 use crate::mir::interpret::ConstValue;
 use crate::ty::{layout, query::TyCtxtAt, tls, FnSig, Ty, ValTree};
@@ -162,9 +162,9 @@ impl fmt::Display for InvalidProgramInfo<'_> {
             AlreadyReported(ErrorGuaranteed { .. }) => {
                 write!(f, "encountered constants with type errors, stopping evaluation")
             }
-            Layout(ref err) => write!(f, "{}", err),
-            FnAbiAdjustForForeignAbi(ref err) => write!(f, "{}", err),
-            SizeOfUnsizedType(ty) => write!(f, "size_of called on unsized type `{}`", ty),
+            Layout(ref err) => write!(f, "{err}"),
+            FnAbiAdjustForForeignAbi(ref err) => write!(f, "{err}"),
+            SizeOfUnsizedType(ty) => write!(f, "size_of called on unsized type `{ty}`"),
         }
     }
 }
@@ -205,14 +205,10 @@ impl fmt::Display for CheckInAllocMsg {
 /// Details of an access to uninitialized bytes where it is not allowed.
 #[derive(Debug)]
 pub struct UninitBytesAccess {
-    /// Location of the original memory access.
-    pub access_offset: Size,
-    /// Size of the original memory access.
-    pub access_size: Size,
-    /// Location of the first uninitialized byte that was accessed.
-    pub uninit_offset: Size,
-    /// Number of consecutive uninitialized bytes that were accessed.
-    pub uninit_size: Size,
+    /// Range of the original memory access.
+    pub access: AllocRange,
+    /// Range of the uninit memory that was encountered. (Might not be maximal.)
+    pub uninit: AllocRange,
 }
 
 /// Information about a size mismatch.
@@ -308,30 +304,28 @@ impl fmt::Display for UndefinedBehaviorInfo<'_> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         use UndefinedBehaviorInfo::*;
         match self {
-            Ub(msg) => write!(f, "{}", msg),
+            Ub(msg) => write!(f, "{msg}"),
             Unreachable => write!(f, "entering unreachable code"),
             BoundsCheckFailed { ref len, ref index } => {
-                write!(f, "indexing out of bounds: the len is {} but the index is {}", len, index)
+                write!(f, "indexing out of bounds: the len is {len} but the index is {index}")
             }
             DivisionByZero => write!(f, "dividing by zero"),
             RemainderByZero => write!(f, "calculating the remainder with a divisor of zero"),
             DivisionOverflow => write!(f, "overflow in signed division (dividing MIN by -1)"),
             RemainderOverflow => write!(f, "overflow in signed remainder (dividing MIN by -1)"),
             PointerArithOverflow => write!(f, "overflowing in-bounds pointer arithmetic"),
-            InvalidMeta(msg) => write!(f, "invalid metadata in wide pointer: {}", msg),
+            InvalidMeta(msg) => write!(f, "invalid metadata in wide pointer: {msg}"),
             InvalidVtableDropFn(sig) => write!(
                 f,
-                "invalid drop function signature: got {}, expected exactly one argument which must be a pointer type",
-                sig
+                "invalid drop function signature: got {sig}, expected exactly one argument which must be a pointer type",
             ),
             InvalidVtableSize => {
                 write!(f, "invalid vtable: size is bigger than largest supported object")
             }
-            InvalidVtableAlignment(msg) => write!(f, "invalid vtable: alignment {}", msg),
+            InvalidVtableAlignment(msg) => write!(f, "invalid vtable: alignment {msg}"),
             UnterminatedCString(p) => write!(
                 f,
-                "reading a null-terminated string starting at {:?} with no null found before end of allocation",
-                p,
+                "reading a null-terminated string starting at {p:?} with no null found before end of allocation",
             ),
             PointerUseAfterFree(a) => {
                 write!(f, "pointer to {a:?} was dereferenced after this allocation got freed")
@@ -359,41 +353,36 @@ impl fmt::Display for UndefinedBehaviorInfo<'_> {
             }
             AlignmentCheckFailed { required, has } => write!(
                 f,
-                "accessing memory with alignment {}, but alignment {} is required",
-                has.bytes(),
-                required.bytes()
+                "accessing memory with alignment {has}, but alignment {required} is required",
+                has = has.bytes(),
+                required = required.bytes()
             ),
             WriteToReadOnly(a) => write!(f, "writing to {a:?} which is read-only"),
             DerefFunctionPointer(a) => write!(f, "accessing {a:?} which contains a function"),
             ValidationFailure { path: None, msg } => {
-                write!(f, "constructing invalid value: {}", msg)
+                write!(f, "constructing invalid value: {msg}")
             }
             ValidationFailure { path: Some(path), msg } => {
-                write!(f, "constructing invalid value at {}: {}", path, msg)
+                write!(f, "constructing invalid value at {path}: {msg}")
             }
             InvalidBool(b) => {
-                write!(f, "interpreting an invalid 8-bit value as a bool: 0x{:02x}", b)
+                write!(f, "interpreting an invalid 8-bit value as a bool: 0x{b:02x}")
             }
             InvalidChar(c) => {
-                write!(f, "interpreting an invalid 32-bit value as a char: 0x{:08x}", c)
+                write!(f, "interpreting an invalid 32-bit value as a char: 0x{c:08x}")
             }
-            InvalidTag(val) => write!(f, "enum value has invalid tag: {:x}", val),
+            InvalidTag(val) => write!(f, "enum value has invalid tag: {val:x}"),
             InvalidFunctionPointer(p) => {
-                write!(f, "using {:?} as function pointer but it does not point to a function", p)
+                write!(f, "using {p:?} as function pointer but it does not point to a function")
             }
-            InvalidStr(err) => write!(f, "this string is not valid UTF-8: {}", err),
-            InvalidUninitBytes(Some((alloc, access))) => write!(
+            InvalidStr(err) => write!(f, "this string is not valid UTF-8: {err}"),
+            InvalidUninitBytes(Some((alloc, info))) => write!(
                 f,
-                "reading {} byte{} of memory starting at {:?}, \
-                 but {} byte{} {} uninitialized starting at {:?}, \
+                "reading memory at {alloc:?}{access:?}, \
+                 but memory is uninitialized at {uninit:?}, \
                  and this operation requires initialized memory",
-                access.access_size.bytes(),
-                pluralize!(access.access_size.bytes()),
-                Pointer::new(*alloc, access.access_offset),
-                access.uninit_size.bytes(),
-                pluralize!(access.uninit_size.bytes()),
-                pluralize!("is", access.uninit_size.bytes()),
-                Pointer::new(*alloc, access.uninit_offset),
+                access = info.access,
+                uninit = info.uninit,
             ),
             InvalidUninitBytes(None) => write!(
                 f,
@@ -402,8 +391,7 @@ impl fmt::Display for UndefinedBehaviorInfo<'_> {
             DeadLocal => write!(f, "accessing a dead local variable"),
             ScalarSizeMismatch(self::ScalarSizeMismatch { target_size, data_size }) => write!(
                 f,
-                "scalar size mismatch: expected {} bytes but got {} bytes instead",
-                target_size, data_size
+                "scalar size mismatch: expected {target_size} bytes but got {data_size} bytes instead",
             ),
             UninhabitedEnumVariantWritten => {
                 write!(f, "writing discriminant of an uninhabited enum")
@@ -437,13 +425,13 @@ impl fmt::Display for UnsupportedOpInfo {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         use UnsupportedOpInfo::*;
         match self {
-            Unsupported(ref msg) => write!(f, "{}", msg),
+            Unsupported(ref msg) => write!(f, "{msg}"),
             ReadPointerAsBytes => write!(f, "unable to turn pointer into raw bytes"),
             PartialPointerOverwrite(ptr) => {
-                write!(f, "unable to overwrite parts of a pointer in memory at {:?}", ptr)
+                write!(f, "unable to overwrite parts of a pointer in memory at {ptr:?}")
             }
-            ThreadLocalStatic(did) => write!(f, "cannot access thread local static ({:?})", did),
-            ReadExternStatic(did) => write!(f, "cannot read from extern static ({:?})", did),
+            ThreadLocalStatic(did) => write!(f, "cannot access thread local static ({did:?})"),
+            ReadExternStatic(did) => write!(f, "cannot read from extern static ({did:?})"),
         }
     }
 }
@@ -526,11 +514,11 @@ impl fmt::Display for InterpError<'_> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         use InterpError::*;
         match *self {
-            Unsupported(ref msg) => write!(f, "{}", msg),
-            InvalidProgram(ref msg) => write!(f, "{}", msg),
-            UndefinedBehavior(ref msg) => write!(f, "{}", msg),
-            ResourceExhaustion(ref msg) => write!(f, "{}", msg),
-            MachineStop(ref msg) => write!(f, "{}", msg),
+            Unsupported(ref msg) => write!(f, "{msg}"),
+            InvalidProgram(ref msg) => write!(f, "{msg}"),
+            UndefinedBehavior(ref msg) => write!(f, "{msg}"),
+            ResourceExhaustion(ref msg) => write!(f, "{msg}"),
+            MachineStop(ref msg) => write!(f, "{msg}"),
         }
     }
 }

src/test/ui/intrinsics/intrinsic-raw_eq-const-padding.stderr

@@ -2,7 +2,7 @@ error[E0080]: evaluation of constant value failed
   --> $DIR/intrinsic-raw_eq-const-padding.rs:6:5
    |
 LL |     std::intrinsics::raw_eq(&(1_u8, 2_u16), &(1_u8, 2_u16))
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ reading 4 bytes of memory starting at alloc3, but 1 byte is uninitialized starting at alloc3+0x1, and this operation requires initialized memory
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ reading memory at alloc3[0x0..0x4], but memory is uninitialized at [0x1..0x2], and this operation requires initialized memory
 
 error: aborting due to previous error