Unsafecell fix (#32)

* Bumped patch release,updated layout for Cell and UnsafeCell due to rustc bug.

Link to rust bug rust-lang/rust#68206

* Travis config:remove Cargo.lock after beta builds

* Fix previous commit

.travis.yml

@@ -35,6 +35,9 @@ script:
   - cd "${TRAVIS_BUILD_DIR}/testing/version_compatibility/impl_0"
   - cargo +beta build
 
+  - cd "${TRAVIS_BUILD_DIR}/"
+  - rm Cargo.lock
+
   - cd "${TRAVIS_BUILD_DIR}/examples/0_modules_and_interface_types/impl/"
   - cargo check
 

Changelog.md

@@ -2,6 +2,21 @@ This is the changelog,summarising changes in each version(some minor changes may
 
 # 0.8
 
+### 0.8.2
+
+Breaking Change(caused by soundness fix in rustc):
+
+[This unsoundness bug for all Cell-like std types](https://github.com/rust-lang/rust/issues/68206) is going to be solved by making UnsafeCell not propagate niches.
+
+In preparation for this change,this library will not propagate niches from T into `*Cell<T>`,
+this will cause runtime errors when loading libraries containing either `*Cell` type wrapping a type with non-zero optimizations (including references,and`NonZero*` types),
+and compile-time errors when putting `Option<Cell<NonZero>>` in ffi boundaries.
+
+Dynamic libraries built on a previous patch release might have to be built from scratch,
+if they contain the previously mentioned types in their API.
+
+### 0.8.0
+
 Added checks when loading dynamic libraries to ensure that Rust doesn't change how it represents 
 zero-sized types in the "C" ABI.
 This means that in some rare cases,it won't be possible to link dynamic libraries across a 

abi_stable/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "abi_stable"
-version = "0.8.1"
+version = "0.8.2"
 authors = ["rodrimati1992 <rodrimatt1985@gmail.com>"]
 edition="2018"
 license = "MIT/Apache-2.0"

abi_stable/src/abi_stability/stable_abi_trait.rs

@@ -1188,10 +1188,13 @@ mod rust_1_36_impls{
 
 /////////////
 
-macro_rules! impl_sabi_for_transparent {
+macro_rules! impl_sabi_for_newtype {
+    (@trans transparent)=>{ P::IsNonZeroType };
+    (@trans C)=>{ False };
     (
         $type_constr:ident
         $(where[ $($where_clause:tt)* ])* ,
+        $transparency:ident,
         $type_name:literal,
         $mod_path:expr
     ) => (
@@ -1208,7 +1211,7 @@ macro_rules! impl_sabi_for_transparent {
             $($($where_clause)*)*
         {
             type Kind=ValueKind;
-            type IsNonZeroType = P::IsNonZeroType;
+            type IsNonZeroType = impl_sabi_for_newtype!(@trans $transparency);
 
             const S_LAYOUT: &'static TypeLayout = {
                 const MONO_TYPE_LAYOUT:&'static MonoTypeLayout=&MonoTypeLayout::new(
@@ -1243,11 +1246,12 @@ macro_rules! impl_sabi_for_transparent {
 }
 
 
-impl_sabi_for_transparent!{ Wrapping    ,"Wrapping"    ,"std::num" }
-impl_sabi_for_transparent!{ Pin         ,"Pin"         ,"std::pin" }
-impl_sabi_for_transparent!{ ManuallyDrop,"ManuallyDrop","std::mem" }
-impl_sabi_for_transparent!{ Cell        ,"Cell"        ,"std::cell" }
-impl_sabi_for_transparent!{ UnsafeCell  ,"UnsafeCell"  ,"std::cell" }
+impl_sabi_for_newtype!{ Wrapping    ,transparent,"Wrapping"    ,"std::num" }
+impl_sabi_for_newtype!{ Pin         ,transparent,"Pin"         ,"std::pin" }
+impl_sabi_for_newtype!{ ManuallyDrop,transparent,"ManuallyDrop","std::mem" }
+
+impl_sabi_for_newtype!{ Cell        ,C,"Cell"        ,"std::cell" }
+impl_sabi_for_newtype!{ UnsafeCell  ,C,"UnsafeCell"  ,"std::cell" }
 
 /////////////