[util] Use new padding_needed_for implementation (#833)

Delete the existing tests since we can test using our existing Kani
harness that we used with the old implementation.

Release 0.8.0-alpha.3.

Cargo.toml

@@ -15,7 +15,7 @@
 [package]
 edition = "2018"
 name = "zerocopy"
-version = "0.8.0-alpha.2"
+version = "0.8.0-alpha.3"
 authors = ["Joshua Liebow-Feeser <[email protected]>"]
 description = "Utilities for zero-copy parsing and serialization"
 license = "BSD-2-Clause OR Apache-2.0 OR MIT"
@@ -47,13 +47,13 @@ simd-nightly = ["simd"]
 __internal_use_only_features_that_work_on_stable = ["alloc", "derive", "simd"]
 
 [dependencies]
-zerocopy-derive = { version = "=0.8.0-alpha.2", path = "zerocopy-derive", optional = true }
+zerocopy-derive = { version = "=0.8.0-alpha.3", path = "zerocopy-derive", optional = true }
 
 # The "associated proc macro pattern" ensures that the versions of zerocopy and
 # zerocopy-derive remain equal, even if the 'derive' feature isn't used.
 # See: https://github.com/matklad/macro-dep-test
 [target.'cfg(any())'.dependencies]
-zerocopy-derive = { version = "=0.8.0-alpha.2", path = "zerocopy-derive" }
+zerocopy-derive = { version = "=0.8.0-alpha.3", path = "zerocopy-derive" }
 
 [dev-dependencies]
 assert_matches = "1.5"
@@ -72,6 +72,6 @@ testutil = { path = "testutil" }
 # CI test failures.
 trybuild = { version = "=1.0.89", features = ["diff"] }
 # In tests, unlike in production, zerocopy-derive is not optional
-zerocopy-derive = { version = "=0.8.0-alpha.2", path = "zerocopy-derive" }
+zerocopy-derive = { version = "=0.8.0-alpha.3", path = "zerocopy-derive" }
 # TODO(#381) Remove this dependency once we have our own layout gadgets.
 elain = "0.3.0"

src/lib.rs

@@ -533,7 +533,7 @@ impl DstLayout {
     #[doc(hidden)]
     #[inline]
     pub const fn extend(self, field: DstLayout, repr_packed: Option<NonZeroUsize>) -> Self {
-        use util::{core_layout::padding_needed_for, max, min};
+        use util::{max, min, padding_needed_for};
 
         // If `repr_packed` is `None`, there are no alignment constraints, and
         // the value can be defaulted to `THEORETICAL_MAX_ALIGN`.
@@ -672,7 +672,7 @@ impl DstLayout {
     #[doc(hidden)]
     #[inline]
     pub const fn pad_to_align(self) -> Self {
-        use util::core_layout::padding_needed_for;
+        use util::padding_needed_for;
 
         let size_info = match self.size_info {
             // For sized layouts, we add the minimum amount of trailing padding
@@ -882,8 +882,8 @@ impl DstLayout {
                 //   up to the next multiple of the alignment will bring
                 //   `self_bytes` up to `max_total_bytes`.
                 #[allow(clippy::arithmetic_side_effects)]
-                let self_bytes = without_padding
-                    + util::core_layout::padding_needed_for(without_padding, self.align);
+                let self_bytes =
+                    without_padding + util::padding_needed_for(without_padding, self.align);
                 (elems, self_bytes)
             }
         };
@@ -5997,8 +5997,7 @@ mod tests {
                     }) => {
                         let padded_size = |elems| {
                             let without_padding = offset + elems * elem_size;
-                            without_padding
-                                + util::core_layout::padding_needed_for(without_padding, align)
+                            without_padding + util::padding_needed_for(without_padding, align)
                         };
 
                         let resulting_size = padded_size(elems);
@@ -6027,7 +6026,7 @@ mod tests {
                 let min_size = match layout.size_info {
                     SizeInfo::Sized { _size } => _size,
                     SizeInfo::SliceDst(TrailingSliceLayout { _offset, .. }) => {
-                        _offset + util::core_layout::padding_needed_for(_offset, layout.align)
+                        _offset + util::padding_needed_for(_offset, layout.align)
                     }
                 };
 
@@ -6104,8 +6103,7 @@ mod tests {
                         //
                         // ...then Rust will automatically round the type's size
                         // up to 2.
-                        _size: args.offset
-                            + util::core_layout::padding_needed_for(args.offset, args.align),
+                        _size: args.offset + util::padding_needed_for(args.offset, args.align),
                     },
                 };
                 DstLayout { size_info, align: args.align }
@@ -6153,8 +6151,8 @@ mod tests {
                 //   count. We expect that the size of the object should be
                 //   `offset + elem_size * elems` rounded up to the next
                 //   alignment.
-                let expected_size = without_padding
-                    + util::core_layout::padding_needed_for(without_padding, args.align);
+                let expected_size =
+                    without_padding + util::padding_needed_for(without_padding, args.align);
                 assert_eq!(expected_size, size, "{}", assert_msg);
 
                 // For zero-sized element types,
@@ -8508,7 +8506,7 @@ mod proofs {
 
     #[kani::proof]
     fn prove_dst_layout_extend() {
-        use crate::util::{core_layout::padding_needed_for, max, min};
+        use crate::util::{max, min, padding_needed_for};
 
         let base: DstLayout = kani::any();
         let field: DstLayout = kani::any();
@@ -8649,7 +8647,7 @@ mod proofs {
 
     #[kani::proof]
     fn prove_dst_layout_pad_to_align() {
-        use crate::util::core_layout::padding_needed_for;
+        use crate::util::padding_needed_for;
 
         let layout: DstLayout = kani::any();