Implement Inline Size Assertion Annotations

src/lib.rs

@@ -4484,7 +4484,7 @@ macro_rules! transmute_ref {
             // value returned from this branch.
             let u;
 
-            $crate::assert_size_eq!(t, u);
+            $crate::assert_type_size_eq!(t, u);
             $crate::assert_align_gt_eq!(t, u);
 
             &u
@@ -4495,7 +4495,7 @@ macro_rules! transmute_ref {
             //   `AssertSrcIsImmutable`, `AssertDstIsFromBytes`, and
             //   `AssertDstIsImmutable` above.
             // - We know that `size_of::<Src>() == size_of::<Dst>()` thanks to
-            //   the use of `assert_size_eq!` above.
+            //   the use of `assert_type_size_eq!` above.
             // - We know that `align_of::<Src>() >= align_of::<Dst>()` thanks to
             //   the use of `assert_align_gt_eq!` above.
             let u = unsafe { $crate::macro_util::transmute_ref(e) };
@@ -4640,14 +4640,14 @@ macro_rules! transmute_mut {
             // the value returned from this branch.
             let u;
 
-            $crate::assert_size_eq!(t, u);
+            $crate::assert_type_size_eq!(t, u);
             $crate::assert_align_gt_eq!(t, u);
 
             &mut u
         } else {
             // SAFETY: For source type `Src` and destination type `Dst`:
             // - We know that `size_of::<Src>() == size_of::<Dst>()` thanks to
-            //   the use of `assert_size_eq!` above.
+            //   the use of `assert_type_size_eq!` above.
             // - We know that `align_of::<Src>() >= align_of::<Dst>()` thanks to
             //   the use of `assert_align_gt_eq!` above.
             let u = unsafe { $crate::macro_util::transmute_mut(e) };

src/macro_util.rs

@@ -339,7 +339,7 @@ macro_rules! assert_align_gt_eq {
 /// `transmute_ref!` and `transmute_mut!`.
 #[doc(hidden)] // `#[macro_export]` bypasses this module's `#[doc(hidden)]`.
 #[macro_export]
-macro_rules! assert_size_eq {
+macro_rules! assert_type_size_eq {
     ($t:ident, $u: ident) => {{
         // The comments here should be read in the context of this macro's
         // invocations in `transmute_ref!` and `transmute_mut!`.
@@ -359,6 +359,19 @@ macro_rules! assert_size_eq {
     }};
 }
 
+/// Panic if the expression evaluates to `false`.
+#[doc(hidden)]
+#[macro_export]
+macro_rules! static_const_assert {
+    ($x:expr $(,)?) => {
+        #[allow(unknown_lints, eq_op)]
+        const _: [(); 0 - !{
+            const ASSERT: bool = $x;
+            ASSERT
+        } as usize] = [];
+    };
+}
+
 /// Transmutes a reference of one type to a reference of another type.
 ///
 /// # Safety

tests/ui-msrv/transmute-mut-dst-generic.stderr

@@ -6,7 +6,7 @@ error[E0512]: cannot transmute between types of different sizes, or dependently-
    |
    = note: source type: `u8` (8 bits)
    = note: target type: `T` (this type does not have a fixed size)
-   = note: this error originates in the macro `$crate::assert_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::assert_type_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0512]: cannot transmute between types of different sizes, or dependently-sized types
   --> tests/ui-msrv/transmute-mut-dst-generic.rs:17:5

tests/ui-msrv/transmute-mut-dst-unsized.stderr

@@ -49,7 +49,7 @@ note: required by a bound in `transmute`
    |
    |     pub fn transmute<T, U>(e: T) -> U;
    |                         ^ required by this bound in `transmute`
-   = note: this error originates in the macro `$crate::assert_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::assert_type_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0277]: the size for values of type `[u8]` cannot be known at compilation time
   --> tests/ui-msrv/transmute-mut-dst-unsized.rs:17:32

tests/ui-msrv/transmute-mut-size-decrease.stderr

@@ -6,7 +6,7 @@ error[E0512]: cannot transmute between types of different sizes, or dependently-
    |
    = note: source type: `[u8; 2]` (16 bits)
    = note: target type: `u8` (8 bits)
-   = note: this error originates in the macro `$crate::assert_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::assert_type_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0658]: mutable references are not allowed in constants
   --> tests/ui-msrv/transmute-mut-size-decrease.rs:17:47

tests/ui-msrv/transmute-mut-size-increase.stderr

@@ -6,7 +6,7 @@ error[E0512]: cannot transmute between types of different sizes, or dependently-
    |
    = note: source type: `u8` (8 bits)
    = note: target type: `[u8; 2]` (16 bits)
-   = note: this error originates in the macro `$crate::assert_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::assert_type_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0658]: mutable references are not allowed in constants
   --> tests/ui-msrv/transmute-mut-size-increase.rs:17:52

tests/ui-msrv/transmute-mut-src-dst-generic.stderr

@@ -6,7 +6,7 @@ error[E0512]: cannot transmute between types of different sizes, or dependently-
    |
    = note: source type: `T` (this type does not have a fixed size)
    = note: target type: `U` (this type does not have a fixed size)
-   = note: this error originates in the macro `$crate::assert_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::assert_type_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0512]: cannot transmute between types of different sizes, or dependently-sized types
   --> tests/ui-msrv/transmute-mut-src-dst-generic.rs:20:5

tests/ui-msrv/transmute-mut-src-dst-unsized.stderr

@@ -63,7 +63,7 @@ note: required by a bound in `transmute`
    |
    |     pub fn transmute<T, U>(e: T) -> U;
    |                      ^ required by this bound in `transmute`
-   = note: this error originates in the macro `$crate::assert_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::assert_type_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0277]: the size for values of type `[u8]` cannot be known at compilation time
   --> tests/ui-msrv/transmute-mut-src-dst-unsized.rs:17:36
@@ -191,7 +191,7 @@ note: required by a bound in `transmute`
    |
    |     pub fn transmute<T, U>(e: T) -> U;
    |                         ^ required by this bound in `transmute`
-   = note: this error originates in the macro `$crate::assert_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::assert_type_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0277]: the size for values of type `[u8]` cannot be known at compilation time
   --> tests/ui-msrv/transmute-mut-src-dst-unsized.rs:17:36

tests/ui-msrv/transmute-mut-src-generic.stderr

@@ -6,7 +6,7 @@ error[E0512]: cannot transmute between types of different sizes, or dependently-
    |
    = note: source type: `T` (this type does not have a fixed size)
    = note: target type: `u8` (8 bits)
-   = note: this error originates in the macro `$crate::assert_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::assert_type_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0512]: cannot transmute between types of different sizes, or dependently-sized types
   --> tests/ui-msrv/transmute-mut-src-generic.rs:17:5

tests/ui-msrv/transmute-mut-src-unsized.stderr

@@ -49,7 +49,7 @@ note: required by a bound in `transmute`
    |
    |     pub fn transmute<T, U>(e: T) -> U;
    |                      ^ required by this bound in `transmute`
-   = note: this error originates in the macro `$crate::assert_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::assert_type_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0277]: the size for values of type `[u8]` cannot be known at compilation time
   --> tests/ui-msrv/transmute-mut-src-unsized.rs:16:35
@@ -176,4 +176,4 @@ error[E0277]: the size for values of type `[u8]` cannot be known at compilation
    |
    = help: the trait `Sized` is not implemented for `[u8]`
    = note: all function arguments must have a statically known size
-   = note: this error originates in the macro `$crate::assert_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::assert_type_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)

tests/ui-msrv/transmute-ref-dst-generic.stderr

@@ -6,7 +6,7 @@ error[E0512]: cannot transmute between types of different sizes, or dependently-
    |
    = note: source type: `u8` (8 bits)
    = note: target type: `T` (this type does not have a fixed size)
-   = note: this error originates in the macro `$crate::assert_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::assert_type_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0512]: cannot transmute between types of different sizes, or dependently-sized types
   --> tests/ui-msrv/transmute-ref-dst-generic.rs:17:5

tests/ui-msrv/transmute-ref-dst-unsized.stderr

@@ -49,7 +49,7 @@ note: required by a bound in `transmute`
    |
    |     pub fn transmute<T, U>(e: T) -> U;
    |                         ^ required by this bound in `transmute`
-   = note: this error originates in the macro `$crate::assert_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::assert_type_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0277]: the size for values of type `[u8]` cannot be known at compilation time
   --> tests/ui-msrv/transmute-ref-dst-unsized.rs:17:28

tests/ui-msrv/transmute-ref-size-decrease.stderr

@@ -6,4 +6,4 @@ error[E0512]: cannot transmute between types of different sizes, or dependently-
    |
    = note: source type: `[u8; 2]` (16 bits)
    = note: target type: `u8` (8 bits)
-   = note: this error originates in the macro `$crate::assert_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::assert_type_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)

tests/ui-msrv/transmute-ref-size-increase.stderr

@@ -6,4 +6,4 @@ error[E0512]: cannot transmute between types of different sizes, or dependently-
    |
    = note: source type: `u8` (8 bits)
    = note: target type: `[u8; 2]` (16 bits)
-   = note: this error originates in the macro `$crate::assert_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::assert_type_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)

tests/ui-msrv/transmute-ref-src-dst-generic.stderr

@@ -6,7 +6,7 @@ error[E0512]: cannot transmute between types of different sizes, or dependently-
    |
    = note: source type: `T` (this type does not have a fixed size)
    = note: target type: `U` (this type does not have a fixed size)
-   = note: this error originates in the macro `$crate::assert_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::assert_type_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0512]: cannot transmute between types of different sizes, or dependently-sized types
   --> tests/ui-msrv/transmute-ref-src-dst-generic.rs:18:5

tests/ui-msrv/transmute-ref-src-dst-unsized.stderr

@@ -63,7 +63,7 @@ note: required by a bound in `transmute`
    |
    |     pub fn transmute<T, U>(e: T) -> U;
    |                      ^ required by this bound in `transmute`
-   = note: this error originates in the macro `$crate::assert_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::assert_type_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0277]: the size for values of type `[u8]` cannot be known at compilation time
   --> tests/ui-msrv/transmute-ref-src-dst-unsized.rs:17:32
@@ -191,7 +191,7 @@ note: required by a bound in `transmute`
    |
    |     pub fn transmute<T, U>(e: T) -> U;
    |                         ^ required by this bound in `transmute`
-   = note: this error originates in the macro `$crate::assert_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::assert_type_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0277]: the size for values of type `[u8]` cannot be known at compilation time
   --> tests/ui-msrv/transmute-ref-src-dst-unsized.rs:17:32

tests/ui-msrv/transmute-ref-src-generic.stderr

@@ -6,7 +6,7 @@ error[E0512]: cannot transmute between types of different sizes, or dependently-
    |
    = note: source type: `T` (this type does not have a fixed size)
    = note: target type: `u8` (8 bits)
-   = note: this error originates in the macro `$crate::assert_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::assert_type_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0512]: cannot transmute between types of different sizes, or dependently-sized types
   --> tests/ui-msrv/transmute-ref-src-generic.rs:17:5

tests/ui-msrv/transmute-ref-src-unsized.stderr

@@ -49,7 +49,7 @@ note: required by a bound in `transmute`
    |
    |     pub fn transmute<T, U>(e: T) -> U;
    |                      ^ required by this bound in `transmute`
-   = note: this error originates in the macro `$crate::assert_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::assert_type_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0277]: the size for values of type `[u8]` cannot be known at compilation time
   --> tests/ui-msrv/transmute-ref-src-unsized.rs:16:31
@@ -176,4 +176,4 @@ error[E0277]: the size for values of type `[u8]` cannot be known at compilation
    |
    = help: the trait `Sized` is not implemented for `[u8]`
    = note: all function arguments must have a statically known size
-   = note: this error originates in the macro `$crate::assert_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::assert_type_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)

tests/ui-nightly/inline_assert_size_eq_failed.rs

@@ -0,0 +1,11 @@
+extern crate zerocopy;
+extern crate zerocopy_derive;
+use zerocopy::*;
+use zerocopy_derive::assert_size_eq;
+
+#[assert_size_eq(1)]
+struct TestSizeNeqStruct {
+    i: i32,
+}
+
+fn main() {}

tests/ui-nightly/inline_assert_size_eq_failed.stderr

@@ -0,0 +1,7 @@
+error[E0080]: evaluation of constant value failed
+ --> tests/ui-nightly/inline_assert_size_eq_failed.rs:6:1
+  |
+6 | #[assert_size_eq(1)]
+  | ^^^^^^^^^^^^^^^^^^^^ attempt to compute `0_usize - 1_usize`, which would overflow
+  |
+  = note: this error originates in the macro `static_const_assert` which comes from the expansion of the attribute macro `assert_size_eq` (in Nightly builds, run with -Z macro-backtrace for more info)

tests/ui-nightly/transmute-mut-dst-generic.stderr

@@ -6,7 +6,7 @@ error[E0512]: cannot transmute between types of different sizes, or dependently-
    |
    = note: source type: `u8` (8 bits)
    = note: target type: `T` (this type does not have a fixed size)
-   = note: this error originates in the macro `$crate::assert_size_eq` which comes from the expansion of the macro `transmute_mut` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::assert_type_size_eq` which comes from the expansion of the macro `transmute_mut` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0512]: cannot transmute between types of different sizes, or dependently-sized types
   --> tests/ui-nightly/transmute-mut-dst-generic.rs:17:5

tests/ui-nightly/transmute-mut-dst-unsized.stderr

@@ -52,7 +52,7 @@ note: required by an implicit `Sized` bound in `transmute`
    |
    |     pub fn transmute<Src, Dst>(src: Src) -> Dst;
    |                           ^^^ required by the implicit `Sized` requirement on this type parameter in `transmute`
-   = note: this error originates in the macro `$crate::assert_size_eq` which comes from the expansion of the macro `transmute_mut` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::assert_type_size_eq` which comes from the expansion of the macro `transmute_mut` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0277]: the size for values of type `[u8]` cannot be known at compilation time
   --> tests/ui-nightly/transmute-mut-dst-unsized.rs:17:32

tests/ui-nightly/transmute-mut-size-decrease.stderr

@@ -6,4 +6,4 @@ error[E0512]: cannot transmute between types of different sizes, or dependently-
    |
    = note: source type: `[u8; 2]` (16 bits)
    = note: target type: `u8` (8 bits)
-   = note: this error originates in the macro `$crate::assert_size_eq` which comes from the expansion of the macro `transmute_mut` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::assert_type_size_eq` which comes from the expansion of the macro `transmute_mut` (in Nightly builds, run with -Z macro-backtrace for more info)

tests/ui-nightly/transmute-mut-size-increase.stderr

@@ -6,4 +6,4 @@ error[E0512]: cannot transmute between types of different sizes, or dependently-
    |
    = note: source type: `u8` (8 bits)
    = note: target type: `[u8; 2]` (16 bits)
-   = note: this error originates in the macro `$crate::assert_size_eq` which comes from the expansion of the macro `transmute_mut` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::assert_type_size_eq` which comes from the expansion of the macro `transmute_mut` (in Nightly builds, run with -Z macro-backtrace for more info)

tests/ui-nightly/transmute-mut-src-dst-generic.stderr

@@ -6,7 +6,7 @@ error[E0512]: cannot transmute between types of different sizes, or dependently-
    |
    = note: source type: `T` (this type does not have a fixed size)
    = note: target type: `U` (this type does not have a fixed size)
-   = note: this error originates in the macro `$crate::assert_size_eq` which comes from the expansion of the macro `transmute_mut` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::assert_type_size_eq` which comes from the expansion of the macro `transmute_mut` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0512]: cannot transmute between types of different sizes, or dependently-sized types
   --> tests/ui-nightly/transmute-mut-src-dst-generic.rs:20:5

tests/ui-nightly/transmute-mut-src-dst-not-references.stderr

@@ -24,4 +24,4 @@ warning: never type fallback affects this call to an `unsafe` function
    = note: for more information, see issue #123748 <https://github.com/rust-lang/rust/issues/123748>
    = help: specify the type explicitly
    = note: `#[warn(never_type_fallback_flowing_into_unsafe)]` on by default
-   = note: this warning originates in the macro `$crate::assert_size_eq` which comes from the expansion of the macro `transmute_mut` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this warning originates in the macro `$crate::assert_type_size_eq` which comes from the expansion of the macro `transmute_mut` (in Nightly builds, run with -Z macro-backtrace for more info)

tests/ui-nightly/transmute-mut-src-dst-unsized.stderr

@@ -149,7 +149,7 @@ note: required by an implicit `Sized` bound in `transmute`
    |
    |     pub fn transmute<Src, Dst>(src: Src) -> Dst;
    |                           ^^^ required by the implicit `Sized` requirement on this type parameter in `transmute`
-   = note: this error originates in the macro `$crate::assert_size_eq` which comes from the expansion of the macro `transmute_mut` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::assert_type_size_eq` which comes from the expansion of the macro `transmute_mut` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0277]: the size for values of type `[u8]` cannot be known at compilation time
   --> tests/ui-nightly/transmute-mut-src-dst-unsized.rs:17:36