Add more precondition check tests

Author: saethlin

library/core/src/ascii/ascii_char.rs

@@ -506,7 +506,7 @@ impl AsciiChar {
     pub const unsafe fn digit_unchecked(d: u8) -> Self {
         assert_unsafe_precondition!(
             check_language_ub,
-            "`AsciiChar::digit_unchecked` input cannot exceed 9.",
+            "`ascii::Char::digit_unchecked` input cannot exceed 9.",
             (d: u8 = d) => d < 10
         );
 

library/core/src/ptr/mod.rs

@@ -1432,7 +1432,8 @@ pub const unsafe fn read<T>(src: *const T) -> T {
             (
                 addr: *const () = src as *const (),
                 align: usize = align_of::<T>(),
-            ) => ub_checks::is_aligned_and_not_null(addr, align)
+                is_zst: bool = T::IS_ZST,
+            ) => ub_checks::is_aligned_and_not_null(addr, align, is_zst)
         );
         crate::intrinsics::read_via_copy(src)
     }
@@ -1637,7 +1638,8 @@ pub const unsafe fn write<T>(dst: *mut T, src: T) {
             (
                 addr: *mut () = dst as *mut (),
                 align: usize = align_of::<T>(),
-            ) => ub_checks::is_aligned_and_not_null(addr, align)
+                is_zst: bool = T::IS_ZST,
+            ) => ub_checks::is_aligned_and_not_null(addr, align, is_zst)
         );
         intrinsics::write_via_move(dst, src)
     }

tests/ui/precondition-checks/alignment.rs

@@ -0,0 +1,11 @@
+//@ run-fail
+//@ compile-flags: -Copt-level=3 -Cdebug-assertions=no -Zub-checks=yes
+//@ error-pattern: unsafe precondition(s) violated: Alignment::new_unchecked requires
+
+#![feature(ptr_alignment_type)]
+
+fn main() {
+    unsafe {
+        std::ptr::Alignment::new_unchecked(0);
+    }
+}

tests/ui/precondition-checks/ascii-char-digit_unchecked.rs

@@ -0,0 +1,11 @@
+//@ run-fail
+//@ compile-flags: -Copt-level=3 -Cdebug-assertions=no -Zub-checks=yes
+//@ error-pattern: unsafe precondition(s) violated: `ascii::Char::digit_unchecked` input cannot exceed 9
+
+#![feature(ascii_char)]
+
+fn main() {
+    unsafe {
+        std::ascii::Char::digit_unchecked(b'a');
+    }
+}

tests/ui/precondition-checks/assert_unchecked.rs

@@ -0,0 +1,9 @@
+//@ run-fail
+//@ compile-flags: -Copt-level=3 -Cdebug-assertions=no -Zub-checks=yes
+//@ error-pattern: unsafe precondition(s) violated: hint::assert_unchecked must never be called when the condition is false
+
+fn main() {
+    unsafe {
+        std::hint::assert_unchecked(false);
+    }
+}

tests/ui/precondition-checks/char-from_u32_unchecked.rs

@@ -0,0 +1,9 @@
+//@ run-fail
+//@ compile-flags: -Copt-level=3 -Cdebug-assertions=no -Zub-checks=yes
+//@ error-pattern: unsafe precondition(s) violated: invalid value for `char`
+
+fn main() {
+    unsafe {
+        char::from_u32_unchecked(0xD801);
+    }
+}

tests/ui/precondition-checks/copy-nonoverlapping.rs

@@ -0,0 +1,25 @@
+//@ run-fail
+//@ compile-flags: -Copt-level=3 -Cdebug-assertions=no -Zub-checks=yes
+//@ error-pattern: unsafe precondition(s) violated: ptr::copy_nonoverlapping requires
+//@ revisions: null_src null_dst misaligned_src misaligned_dst overlapping
+
+use std::ptr;
+
+fn main() {
+    let src = [0u16; 3];
+    let mut dst = [0u16; 3];
+    let src = src.as_ptr();
+    let dst = dst.as_mut_ptr();
+    unsafe {
+        #[cfg(null_src)]
+        ptr::copy_nonoverlapping(ptr::null(), dst, 1);
+        #[cfg(null_dst)]
+        ptr::copy_nonoverlapping(src, ptr::null_mut(), 1);
+        #[cfg(misaligned_src)]
+        ptr::copy_nonoverlapping(src.byte_add(1), dst, 1);
+        #[cfg(misaligned_dst)]
+        ptr::copy_nonoverlapping(src, dst.byte_add(1), 1);
+        #[cfg(overlapping)]
+        ptr::copy_nonoverlapping(dst, dst.add(1), 2);
+    }
+}

tests/ui/precondition-checks/copy.rs

@@ -0,0 +1,23 @@
+//@ run-fail
+//@ compile-flags: -Copt-level=3 -Cdebug-assertions=no -Zub-checks=yes
+//@ error-pattern: unsafe precondition(s) violated: ptr::copy requires
+//@ revisions: null_src null_dst misaligned_src misaligned_dst
+
+use std::ptr;
+
+fn main() {
+    let src = [0u16; 3];
+    let mut dst = [0u16; 3];
+    let src = src.as_ptr();
+    let dst = dst.as_mut_ptr();
+    unsafe {
+        #[cfg(null_src)]
+        ptr::copy(ptr::null(), dst, 1);
+        #[cfg(null_dst)]
+        ptr::copy(src, ptr::null_mut(), 1);
+        #[cfg(misaligned_src)]
+        ptr::copy(src.byte_add(1), dst, 1);
+        #[cfg(misaligned_dst)]
+        ptr::copy(src, dst.byte_add(1), 1);
+    }
+}

tests/ui/precondition-checks/layout.rs

@@ -0,0 +1,15 @@
+//@ run-fail
+//@ compile-flags: -Copt-level=3 -Cdebug-assertions=no -Zub-checks=yes
+//@ error-pattern: unsafe precondition(s) violated: Layout::from_size_align_unchecked requires
+//@ revisions: toolarge badalign
+//@[toolarge] compile-flags: --cfg toolarge
+//@[badalign] compile-flags: --cfg badalign
+
+fn main() {
+    unsafe {
+        #[cfg(toolarge)]
+        std::alloc::Layout::from_size_align_unchecked(isize::MAX as usize, 2);
+        #[cfg(badalign)]
+        std::alloc::Layout::from_size_align_unchecked(1, 3);
+    }
+}