Split alignment calculation from layout calculation

compiler/rustc_middle/src/query/mod.rs

@@ -1373,6 +1373,16 @@ rustc_queries! {
         remap_env_constness
     }
 
+    /// Computes the alignment of a type. Note that this implicitly
+    /// executes in "reveal all" mode, and will normalize the input type.
+    query align_of(
+        key: ty::ParamEnvAnd<'tcx, Ty<'tcx>>
+    ) -> Result<ty::alignment::AbiAndPrefAlign, ty::layout::LayoutError<'tcx>> {
+        depth_limit
+        desc { "computing alignment of `{}`", key.value }
+        remap_env_constness
+    }
+
     /// Compute a `FnAbi` suitable for indirect calls, i.e. to `fn` pointers.
     ///
     /// NB: this doesn't handle virtual calls - those should use `fn_abi_of_instance`

compiler/rustc_middle/src/ty/alignment.rs

@@ -0,0 +1 @@
+pub use rustc_target::abi::AbiAndPrefAlign;

compiler/rustc_middle/src/ty/layout.rs

@@ -560,6 +560,17 @@ impl<'tcx> LayoutOfHelpers<'tcx> for LayoutCx<'tcx, ty::query::TyCtxtAt<'tcx>> {
     }
 }
 
+pub trait AlignOf<'tcx>: LayoutOf<'tcx> {
+    #[inline]
+    fn align_of(&self, ty: Ty<'tcx>) -> Result<AbiAndPrefAlign, LayoutError<'tcx>> {
+        let span = self.layout_tcx_at_span();
+        let tcx = self.tcx().at(span);
+        tcx.align_of(self.param_env().and(ty))
+    }
+}
+
+impl<'tcx, C: LayoutOf<'tcx>> AlignOf<'tcx> for C {}
+
 impl<'tcx, C> TyAbiInterface<'tcx, C> for Ty<'tcx>
 where
     C: HasTyCtxt<'tcx> + HasParamEnv<'tcx>,

compiler/rustc_middle/src/ty/mod.rs

@@ -108,6 +108,7 @@ pub use self::typeck_results::{
 pub mod _match;
 pub mod abstract_const;
 pub mod adjustment;
+pub mod alignment;
 pub mod binding;
 pub mod cast;
 pub mod codec;