Merging upstream version 1.76.0+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

9 files changed, 178 insertions, 2 deletions

diff --git a/tests/ui/packed/dyn-trait.rs b/tests/ui/packed/dyn-trait.rs
new file mode 100644
index 000000000..bb73c26c1
--- /dev/null
+++ b/tests/ui/packed/dyn-trait.rs
@@ -0,0 +1,21 @@
+// run-pass
+use std::ptr::addr_of;
+
+// When the unsized tail is a `dyn Trait`, its alignments is only dynamically known. This means the
+// packed(2) needs to be applied at runtime: the actual alignment of the field is `min(2,
+// usual_alignment)`. Here we check that we do this right by comparing size, alignment, and field
+// offset before and after unsizing.
+fn main() {
+    #[repr(C, packed(2))]
+    struct Packed<T: ?Sized>(u8, core::mem::ManuallyDrop<T>);
+
+    let p = Packed(0, core::mem::ManuallyDrop::new(1));
+    let p: &Packed<usize> = &p;
+    let sized = (core::mem::size_of_val(p), core::mem::align_of_val(p));
+    let sized_offset = unsafe { addr_of!(p.1).cast::<u8>().offset_from(addr_of!(p.0)) };
+    let p: &Packed<dyn Send> = p;
+    let un_sized = (core::mem::size_of_val(p), core::mem::align_of_val(p));
+    let un_sized_offset = unsafe { addr_of!(p.1).cast::<u8>().offset_from(addr_of!(p.0)) };
+    assert_eq!(sized, un_sized);
+    assert_eq!(sized_offset, un_sized_offset);
+}
diff --git a/tests/ui/packed/issue-118537-field-offset-ice.rs b/tests/ui/packed/issue-118537-field-offset-ice.rs
new file mode 100644
index 000000000..657aec640
--- /dev/null
+++ b/tests/ui/packed/issue-118537-field-offset-ice.rs
@@ -0,0 +1,39 @@
+// run-pass
+#![feature(layout_for_ptr)]
+use std::mem;
+
+#[repr(packed(4))]
+struct Slice([u32]);
+
+#[repr(packed(2), C)]
+struct PackedSized {
+    f: u8,
+    d: [u32; 4],
+}
+
+#[repr(packed(2), C)]
+struct PackedUnsized {
+    f: u8,
+    d: Slice,
+}
+
+impl PackedSized {
+    fn unsize(&self) -> &PackedUnsized {
+        // We can't unsize via a generic type since then we get the error
+        // that packed structs with unsized tail don't work if the tail
+        // might need dropping.
+        let len = 4usize;
+        unsafe { mem::transmute((self, len)) }
+    }
+}
+
+fn main() { unsafe {
+    let p = PackedSized { f: 0, d: [1, 2, 3, 4] };
+    let p = p.unsize() as *const PackedUnsized;
+    // Make sure the size computation correctly adds exact 1 byte of padding
+    // in front of the `d` field.
+    assert_eq!(mem::size_of_val_raw(p), 1 + 1 + 4*4);
+    // And likewise for the offset computation.
+    let d = std::ptr::addr_of!((*p).d);
+    assert_eq!(d.cast::<u32>().read_unaligned(), 1);
+} }
diff --git a/tests/ui/packed/issue-118537-field-offset.rs b/tests/ui/packed/issue-118537-field-offset.rs
new file mode 100644
index 000000000..cd17f7679
--- /dev/null
+++ b/tests/ui/packed/issue-118537-field-offset.rs
@@ -0,0 +1,36 @@
+// run-pass
+#![feature(layout_for_ptr)]
+use std::mem;
+
+#[repr(packed, C)]
+struct PackedSized {
+    f: u8,
+    d: [u32; 4],
+}
+
+#[repr(packed, C)]
+struct PackedUnsized {
+    f: u8,
+    d: [u32],
+}
+
+impl PackedSized {
+    fn unsize(&self) -> &PackedUnsized {
+        // We can't unsize via a generic type since then we get the error
+        // that packed structs with unsized tail don't work if the tail
+        // might need dropping.
+        let len = 4usize;
+        unsafe { mem::transmute((self, len)) }
+    }
+}
+
+fn main() { unsafe {
+    let p = PackedSized { f: 0, d: [1, 2, 3, 4] };
+    let p = p.unsize() as *const PackedUnsized;
+    // Make sure the size computation does *not* think there is
+    // any padding in front of the `d` field.
+    assert_eq!(mem::size_of_val_raw(p), 1 + 4*4);
+    // And likewise for the offset computation.
+    let d = std::ptr::addr_of!((*p).d);
+    assert_eq!(d.cast::<u32>().read_unaligned(), 1);
+} }
diff --git a/tests/ui/packed/issue-27060-2.stderr b/tests/ui/packed/issue-27060-2.stderr
index cf5f4e530..7ee732217 100644
--- a/tests/ui/packed/issue-27060-2.stderr
+++ b/tests/ui/packed/issue-27060-2.stderr
@@ -22,6 +22,6 @@ help: the `Box` type always has a statically known size and allocates its conten
 LL |     data: Box<T>,
    |           ++++ +
 
-error: aborting due to previous error
+error: aborting due to 1 previous error
 
 For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/packed/packed-struct-borrow-element-64bit.stderr b/tests/ui/packed/packed-struct-borrow-element-64bit.stderr
index 57630a4b4..a464b1893 100644
--- a/tests/ui/packed/packed-struct-borrow-element-64bit.stderr
+++ b/tests/ui/packed/packed-struct-borrow-element-64bit.stderr
@@ -8,6 +8,6 @@ LL |     let brw = &foo.baz;
    = note: creating a misaligned reference is undefined behavior (even if that reference is never dereferenced)
    = help: copy the field contents to a local variable, or replace the reference with a raw pointer and use `read_unaligned`/`write_unaligned` (loads and stores via `*p` must be properly aligned even when using raw pointers)
 
-error: aborting due to previous error
+error: aborting due to 1 previous error
 
 For more information about this error, try `rustc --explain E0793`.
diff --git a/tests/ui/packed/packed-struct-generic-transmute.rs b/tests/ui/packed/packed-struct-generic-transmute.rs
new file mode 100644
index 000000000..c6264b6d2
--- /dev/null
+++ b/tests/ui/packed/packed-struct-generic-transmute.rs
@@ -0,0 +1,27 @@
+// This assumes the packed and non-packed structs are different sizes.
+
+// the error points to the start of the file, not the line with the
+// transmute
+
+// error-pattern: cannot transmute between types of different sizes, or dependently-sized types
+
+use std::mem;
+
+#[repr(packed)]
+struct Foo<T,S> {
+    bar: T,
+    baz: S
+}
+
+struct Oof<T, S> {
+    rab: T,
+    zab: S
+}
+
+fn main() {
+    let foo = Foo { bar: [1u8, 2, 3, 4, 5], baz: 10i32 };
+    unsafe {
+        let oof: Oof<[u8; 5], i32> = mem::transmute(foo);
+        println!("{:?} {:?}", &oof.rab[..], oof.zab);
+    }
+}
diff --git a/tests/ui/packed/packed-struct-generic-transmute.stderr b/tests/ui/packed/packed-struct-generic-transmute.stderr
new file mode 100644
index 000000000..e91f49884
--- /dev/null
+++ b/tests/ui/packed/packed-struct-generic-transmute.stderr
@@ -0,0 +1,12 @@
+error[E0512]: cannot transmute between types of different sizes, or dependently-sized types
+  --> $DIR/packed-struct-generic-transmute.rs:24:38
+   |
+LL |         let oof: Oof<[u8; 5], i32> = mem::transmute(foo);
+   |                                      ^^^^^^^^^^^^^^
+   |
+   = note: source type: `Foo<[u8; 5], i32>` (72 bits)
+   = note: target type: `Oof<[u8; 5], i32>` (96 bits)
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0512`.
diff --git a/tests/ui/packed/packed-struct-transmute.rs b/tests/ui/packed/packed-struct-transmute.rs
new file mode 100644
index 000000000..a7d284025
--- /dev/null
+++ b/tests/ui/packed/packed-struct-transmute.rs
@@ -0,0 +1,29 @@
+// This assumes the packed and non-packed structs are different sizes.
+
+// the error points to the start of the file, not the line with the
+// transmute
+
+// normalize-stderr-test "\d+ bits" -> "N bits"
+// error-pattern: cannot transmute between types of different sizes, or dependently-sized types
+
+use std::mem;
+
+#[repr(packed)]
+struct Foo {
+    bar: u8,
+    baz: usize
+}
+
+#[derive(Debug)]
+struct Oof {
+    rab: u8,
+    zab: usize
+}
+
+fn main() {
+    let foo = Foo { bar: 1, baz: 10 };
+    unsafe {
+        let oof: Oof = mem::transmute(foo);
+        println!("{:?}", oof);
+    }
+}
diff --git a/tests/ui/packed/packed-struct-transmute.stderr b/tests/ui/packed/packed-struct-transmute.stderr
new file mode 100644
index 000000000..4d75820e9
--- /dev/null
+++ b/tests/ui/packed/packed-struct-transmute.stderr
@@ -0,0 +1,12 @@
+error[E0512]: cannot transmute between types of different sizes, or dependently-sized types
+  --> $DIR/packed-struct-transmute.rs:26:24
+   |
+LL |         let oof: Oof = mem::transmute(foo);
+   |                        ^^^^^^^^^^^^^^
+   |
+   = note: source type: `Foo` (N bits)
+   = note: target type: `Oof` (N bits)
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0512`.