Auto merge of #1366 - gnzlbg:vec, r=emiliov0.38.0

Map vector types to arrays and pass them by value

This PR maps vector types to arrays and passes them by value (that is, they are passed to C as `[T; N]`.  This already allows defining them as a blacklisted opaque type, such that the user can provide its own definition from e.g. `std::arch`.

A subsequent PR should map vector types to unit structs with a private member:

```rust
#[repr(align(16))] pub struct __m128([f32; 4]);
```

to make their alignment at least be correct. This should allow transmuting `std::arch` types to these types properly.

Once that is done, we probably want to detect the canonical vector types (e.g. `__m128`) and pull in the type from `std`/`core`::arch instead.

1 files changed, 9 insertions, 0 deletions

diff --git a/src/codegen/impl_debug.rs b/src/codegen/impl_debug.rs
index ab934ed6..0842d849 100644
--- a/src/codegen/impl_debug.rs
+++ b/src/codegen/impl_debug.rs
@@ -197,6 +197,15 @@ impl<'a> ImplDebug<'a> for Item {
                     ))
                 }
             }
+            TypeKind::Vector(_, len) => {
+                let self_ids = 0..len;
+                Some((
+                    format!("{}({{}})", name),
+                    vec![quote! {
+                        #(format!("{:?}", self.#self_ids)),*
+                    }]
+                ))
+            }
 
             TypeKind::ResolvedTypeRef(t) |
             TypeKind::TemplateAlias(t, _) |