Rollup merge of #100003 - nnethercote:improve-size-assertions, r=lqd

Improve size assertions.

- For any file with four or more size assertions, move them into a
  separate module (as is already done for `hir.rs`).
- Add some more for AST nodes and THIR nodes.
- Put the `hir.rs` ones in alphabetical order.

r? `@lqd`

compiler/rustc_middle/src/mir/syntax.rs

@@ -800,9 +800,6 @@ pub struct Place<'tcx> {
     pub projection: &'tcx List<PlaceElem<'tcx>>,
 }
 
-#[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
-static_assert_size!(Place<'_>, 16);
-
 #[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
 #[derive(TyEncodable, TyDecodable, HashStable)]
 pub enum ProjectionElem<V, T> {
@@ -866,11 +863,6 @@ pub enum ProjectionElem<V, T> {
 /// and the index is a local.
 pub type PlaceElem<'tcx> = ProjectionElem<Local, Ty<'tcx>>;
 
-// This type is fairly frequently used, so we shouldn't unintentionally increase
-// its size.
-#[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
-static_assert_size!(PlaceElem<'_>, 24);
-
 ///////////////////////////////////////////////////////////////////////////
 // Operands
 
@@ -913,9 +905,6 @@ pub enum Operand<'tcx> {
     Constant(Box<Constant<'tcx>>),
 }
 
-#[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
-static_assert_size!(Operand<'_>, 24);
-
 ///////////////////////////////////////////////////////////////////////////
 // Rvalues
 
@@ -1067,9 +1056,6 @@ pub enum Rvalue<'tcx> {
     CopyForDeref(Place<'tcx>),
 }
 
-#[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
-static_assert_size!(Rvalue<'_>, 40);
-
 #[derive(Clone, Copy, Debug, PartialEq, Eq, TyEncodable, TyDecodable, Hash, HashStable)]
 pub enum CastKind {
     /// An exposing pointer to address cast. A cast between a pointer and an integer type, or
@@ -1105,9 +1091,6 @@ pub enum AggregateKind<'tcx> {
     Generator(LocalDefId, SubstsRef<'tcx>, hir::Movability),
 }
 
-#[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
-static_assert_size!(AggregateKind<'_>, 48);
-
 #[derive(Copy, Clone, Debug, PartialEq, Eq, TyEncodable, TyDecodable, Hash, HashStable)]
 pub enum NullOp {
     /// Returns the size of a value of that type
@@ -1171,3 +1154,15 @@ pub enum BinOp {
     /// The `ptr.offset` operator
     Offset,
 }
+
+// Some nodes are used a lot. Make sure they don't unintentionally get bigger.
+#[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
+mod size_asserts {
+    use super::*;
+    // These are in alphabetical order, which is easy to maintain.
+    static_assert_size!(AggregateKind<'_>, 48);
+    static_assert_size!(Operand<'_>, 24);
+    static_assert_size!(Place<'_>, 16);
+    static_assert_size!(PlaceElem<'_>, 24);
+    static_assert_size!(Rvalue<'_>, 40);
+}

compiler/rustc_middle/src/thir.rs

@@ -190,10 +190,6 @@ pub enum StmtKind<'tcx> {
     },
 }
 
-// `Expr` is used a lot. Make sure it doesn't unintentionally get bigger.
-#[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
-rustc_data_structures::static_assert_size!(Expr<'_>, 104);
-
 #[derive(Clone, Debug, Copy, PartialEq, Eq, Hash, HashStable, TyEncodable, TyDecodable)]
 #[derive(TypeFoldable, TypeVisitable)]
 pub struct LocalVarId(pub hir::HirId);
@@ -812,3 +808,14 @@ impl<'tcx> fmt::Display for Pat<'tcx> {
         }
     }
 }
+
+// Some nodes are used a lot. Make sure they don't unintentionally get bigger.
+#[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
+mod size_asserts {
+    use super::*;
+    // These are in alphabetical order, which is easy to maintain.
+    rustc_data_structures::static_assert_size!(Block, 56);
+    rustc_data_structures::static_assert_size!(Expr<'_>, 104);
+    rustc_data_structures::static_assert_size!(Pat<'_>, 24);
+    rustc_data_structures::static_assert_size!(Stmt<'_>, 120);
+}