Use 'final' specifier on leaf classes

Tint makes heavy use of RTTI via virtual methods. Give the compiler the
opportunity to optimize away some of these virtuals.

Bug: tint:1383
Change-Id: I28edfaa0a05bb1a9c506c61c0084542c0aeb37f0
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/82745
Reviewed-by: James Price <jrprice@google.com>
Reviewed-by: David Neto <dneto@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>

src/tint/transform/add_empty_entry_point.h

@@ -21,7 +21,8 @@ namespace tint {
 namespace transform {
 
 /// Add an empty entry point to the module, if no other entry points exist.
-class AddEmptyEntryPoint : public Castable<AddEmptyEntryPoint, Transform> {
+class AddEmptyEntryPoint final
+    : public Castable<AddEmptyEntryPoint, Transform> {
  public:
   /// Constructor
   AddEmptyEntryPoint();

src/tint/transform/add_spirv_block_attribute.h

@@ -28,12 +28,12 @@ namespace transform {
 /// store type of a buffer. If that structure is nested inside another structure
 /// or an array, then it is wrapped inside another structure which gets the
 /// `@internal(spirv_block)` attribute instead.
-class AddSpirvBlockAttribute
+class AddSpirvBlockAttribute final
     : public Castable<AddSpirvBlockAttribute, Transform> {
  public:
   /// SpirvBlockAttribute is an InternalAttribute that is used to decorate a
   // structure that needs a SPIR-V block attribute.
-  class SpirvBlockAttribute
+  class SpirvBlockAttribute final
       : public Castable<SpirvBlockAttribute, ast::InternalAttribute> {
    public:
     /// Constructor

src/tint/transform/array_length_from_uniform.h

@@ -52,7 +52,7 @@ namespace transform {
 ///
 /// @note Depends on the following transforms to have been run first:
 /// * SimplifyPointers
-class ArrayLengthFromUniform
+class ArrayLengthFromUniform final
     : public Castable<ArrayLengthFromUniform, Transform> {
  public:
   /// Constructor
@@ -61,7 +61,7 @@ class ArrayLengthFromUniform
   ~ArrayLengthFromUniform() override;
 
   /// Configuration options for the ArrayLengthFromUniform transform.
-  struct Config : public Castable<Data, transform::Data> {
+  struct Config final : public Castable<Data, transform::Data> {
     /// Constructor
     /// @param ubo_bp the binding point to use for the generated uniform buffer.
     explicit Config(sem::BindingPoint ubo_bp);
@@ -86,7 +86,7 @@ class ArrayLengthFromUniform
   /// Information produced about what the transform did.
   /// If there were no calls to the arrayLength() builtin, then no Result will
   /// be emitted.
-  struct Result : public Castable<Result, transform::Data> {
+  struct Result final : public Castable<Result, transform::Data> {
     /// Constructor
     /// @param used_size_indices Indices into the UBO that are statically used.
     explicit Result(std::unordered_set<uint32_t> used_size_indices);

src/tint/transform/binding_remapper.h

@@ -29,7 +29,7 @@ using BindingPoint = sem::BindingPoint;
 
 /// BindingRemapper is a transform used to remap resource binding points and
 /// access controls.
-class BindingRemapper : public Castable<BindingRemapper, Transform> {
+class BindingRemapper final : public Castable<BindingRemapper, Transform> {
  public:
   /// BindingPoints is a map of old binding point to new binding point
   using BindingPoints = std::unordered_map<BindingPoint, BindingPoint>;
@@ -39,7 +39,7 @@ class BindingRemapper : public Castable<BindingRemapper, Transform> {
 
   /// Remappings is consumed by the BindingRemapper transform.
   /// Data holds information about shader usage and constant buffer offsets.
-  struct Remappings : public Castable<Data, transform::Data> {
+  struct Remappings final : public Castable<Data, transform::Data> {
     /// Constructor
     /// @param bp a map of new binding points
     /// @param ac a map of new access controls

src/tint/transform/builtin_polyfill.h

@@ -21,7 +21,7 @@ namespace tint {
 namespace transform {
 
 /// Implements builtins for backends that do not have a native implementation.
-class BuiltinPolyfill : public Castable<BuiltinPolyfill, Transform> {
+class BuiltinPolyfill final : public Castable<BuiltinPolyfill, Transform> {
  public:
   /// Constructor
   BuiltinPolyfill();
@@ -56,7 +56,7 @@ class BuiltinPolyfill : public Castable<BuiltinPolyfill, Transform> {
 
   /// Config is consumed by the BuiltinPolyfill transform.
   /// Config specifies the builtins that should be polyfilled.
-  struct Config : public Castable<Data, transform::Data> {
+  struct Config final : public Castable<Data, transform::Data> {
     /// Constructor
     /// @param b the list of builtins to polyfill
     explicit Config(const Builtins& b);

src/tint/transform/calculate_array_length.h

@@ -32,11 +32,12 @@ namespace transform {
 ///
 /// @note Depends on the following transforms to have been run first:
 /// * SimplifyPointers
-class CalculateArrayLength : public Castable<CalculateArrayLength, Transform> {
+class CalculateArrayLength final
+    : public Castable<CalculateArrayLength, Transform> {
  public:
   /// BufferSizeIntrinsic is an InternalAttribute that's applied to intrinsic
   /// functions used to obtain the runtime size of a storage buffer.
-  class BufferSizeIntrinsic
+  class BufferSizeIntrinsic final
       : public Castable<BufferSizeIntrinsic, ast::InternalAttribute> {
    public:
     /// Constructor

src/tint/transform/canonicalize_entry_point_io.h

@@ -83,7 +83,7 @@ namespace transform {
 ///
 /// @note Depends on the following transforms to have been run first:
 /// * Unshadow
-class CanonicalizeEntryPointIO
+class CanonicalizeEntryPointIO final
     : public Castable<CanonicalizeEntryPointIO, Transform> {
  public:
   /// ShaderStyle is an enumerator of different ways to emit shader IO.
@@ -99,7 +99,7 @@ class CanonicalizeEntryPointIO
   };
 
   /// Configuration options for the transform.
-  struct Config : public Castable<Config, Data> {
+  struct Config final : public Castable<Config, Data> {
     /// Constructor
     /// @param style the approach to use for emitting shader IO.
     /// @param sample_mask an optional sample mask to combine with shader masks

src/tint/transform/combine_samplers.h

@@ -53,7 +53,7 @@ namespace transform {
 /// information needed to represent a combined sampler in GLSL
 /// (dimensionality, component type, etc). The GLSL writer outputs such
 /// (Tint) Textures as (GLSL) Samplers.
-class CombineSamplers : public Castable<CombineSamplers, Transform> {
+class CombineSamplers final : public Castable<CombineSamplers, Transform> {
  public:
   /// A pair of binding points.
   using SamplerTexturePair = sem::SamplerTexturePair;
@@ -63,7 +63,7 @@ class CombineSamplers : public Castable<CombineSamplers, Transform> {
 
   /// The client-provided mapping from separate texture and sampler binding
   /// points to combined sampler binding point.
-  struct BindingInfo : public Castable<Data, transform::Data> {
+  struct BindingInfo final : public Castable<Data, transform::Data> {
     /// Constructor
     /// @param map the map of all (texture, sampler) -> (combined) pairs
     /// @param placeholder the binding point to use for placeholder samplers.

src/tint/transform/decompose_memory_access.h

@@ -30,14 +30,14 @@ namespace transform {
 /// DecomposeMemoryAccess is a transform used to replace storage and uniform
 /// buffer accesses with a combination of load, store or atomic functions on
 /// primitive types.
-class DecomposeMemoryAccess
+class DecomposeMemoryAccess final
     : public Castable<DecomposeMemoryAccess, Transform> {
  public:
   /// Intrinsic is an InternalAttribute that's used to decorate a stub function
   /// so that the HLSL transforms this into calls to
   /// `[RW]ByteAddressBuffer.Load[N]()` or `[RW]ByteAddressBuffer.Store[N]()`,
   /// with a possible cast.
-  class Intrinsic : public Castable<Intrinsic, ast::InternalAttribute> {
+  class Intrinsic final : public Castable<Intrinsic, ast::InternalAttribute> {
    public:
     /// Intrinsic op
     enum class Op {

src/tint/transform/decompose_strided_array.h

@@ -28,7 +28,7 @@ namespace transform {
 ///
 /// @note Depends on the following transforms to have been run first:
 /// * SimplifyPointers
-class DecomposeStridedArray
+class DecomposeStridedArray final
     : public Castable<DecomposeStridedArray, Transform> {
  public:
   /// Constructor

src/tint/transform/decompose_strided_matrix.h

@@ -28,7 +28,7 @@ namespace transform {
 ///
 /// @note Depends on the following transforms to have been run first:
 /// * SimplifyPointers
-class DecomposeStridedMatrix
+class DecomposeStridedMatrix final
     : public Castable<DecomposeStridedMatrix, Transform> {
  public:
   /// Constructor

src/tint/transform/first_index_offset.h

@@ -58,12 +58,12 @@ namespace transform {
 ///   }
 /// ```
 ///
-class FirstIndexOffset : public Castable<FirstIndexOffset, Transform> {
+class FirstIndexOffset final : public Castable<FirstIndexOffset, Transform> {
  public:
   /// BindingPoint is consumed by the FirstIndexOffset transform.
   /// BindingPoint specifies the binding point of the first index uniform
   /// buffer.
-  struct BindingPoint : public Castable<BindingPoint, transform::Data> {
+  struct BindingPoint final : public Castable<BindingPoint, transform::Data> {
     /// Constructor
     BindingPoint();
 
@@ -83,7 +83,7 @@ class FirstIndexOffset : public Castable<FirstIndexOffset, Transform> {
 
   /// Data is outputted by the FirstIndexOffset transform.
   /// Data holds information about shader usage and constant buffer offsets.
-  struct Data : public Castable<Data, transform::Data> {
+  struct Data final : public Castable<Data, transform::Data> {
     /// Constructor
     /// @param has_vtx_index True if the shader uses vertex_index
     /// @param has_inst_index True if the shader uses instance_index

src/tint/transform/fold_constants.h

@@ -21,7 +21,7 @@ namespace tint {
 namespace transform {
 
 /// FoldConstants transforms the AST by folding constant expressions
-class FoldConstants : public Castable<FoldConstants, Transform> {
+class FoldConstants final : public Castable<FoldConstants, Transform> {
  public:
   /// Constructor
   FoldConstants();

src/tint/transform/fold_trivial_single_use_lets.h

@@ -34,7 +34,7 @@ namespace transform {
 ///   single usage.
 /// These rules prevent any hoisting of the let that may affect execution
 /// behaviour.
-class FoldTrivialSingleUseLets
+class FoldTrivialSingleUseLets final
     : public Castable<FoldTrivialSingleUseLets, Transform> {
  public:
   /// Constructor

src/tint/transform/for_loop_to_loop.h

@@ -22,7 +22,7 @@ namespace transform {
 
 /// ForLoopToLoop is a Transform that converts a for-loop statement into a loop
 /// statement. This is required by the SPIR-V writer.
-class ForLoopToLoop : public Castable<ForLoopToLoop, Transform> {
+class ForLoopToLoop final : public Castable<ForLoopToLoop, Transform> {
  public:
   /// Constructor
   ForLoopToLoop();

src/tint/transform/glsl.h

@@ -29,10 +29,10 @@ namespace transform {
 /// Glsl is a transform used to sanitize a Program for use with the Glsl writer.
 /// Passing a non-sanitized Program to the Glsl writer will result in undefined
 /// behavior.
-class Glsl : public Castable<Glsl, Transform> {
+class Glsl final : public Castable<Glsl, Transform> {
  public:
   /// Configuration options for the Glsl sanitizer transform.
-  struct Config : public Castable<Data, transform::Data> {
+  struct Config final : public Castable<Data, transform::Data> {
     /// Constructor
     /// @param entry_point the root entry point function to generate
     /// @param disable_workgroup_init `true` to disable workgroup memory zero