tint: Fix set of overrides in the shader interface

Since overrides can be used to size workgroup arrays and also as
initializers to module-scope variables, we cannot just consider
overrides that are directly referenced in the shader functions.

This change makes the Resolver track references to overrides whilst
resolving array types and module-scope variable declarations, so that
they are included in the set of overrides reported by the Inspector in
these scenarios.

Fixed: tint:1762
Change-Id: If7501abf3ddcb87a87134ddd578aa4904d204de6
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/110460
Reviewed-by: Ben Clayton <bclayton@google.com>
Commit-Queue: James Price <jrprice@google.com>
Auto-Submit: James Price <jrprice@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>

src/tint/sem/array.h

@@ -23,6 +23,7 @@
 #include "src/tint/sem/node.h"
 #include "src/tint/sem/type.h"
 #include "src/tint/utils/compiler_macros.h"
+#include "src/tint/utils/unique_vector.h"
 
 // Forward declarations
 namespace tint::sem {
@@ -229,6 +230,17 @@ class Array final : public Castable<Array, Type> {
     /// @returns true if this array is runtime sized
     bool IsRuntimeSized() const { return std::holds_alternative<RuntimeArrayCount>(count_); }
 
+    /// Records that this array type (transitively) references the given override variable.
+    /// @param var the module-scope override variable
+    void AddTransitivelyReferencedOverride(const GlobalVariable* var) {
+        referenced_overrides_.Add(var);
+    }
+
+    /// @returns all transitively referenced override variables
+    const utils::UniqueVector<const GlobalVariable*, 4>& TransitivelyReferencedOverrides() const {
+        return referenced_overrides_;
+    }
+
     /// @param symbols the program's symbol table
     /// @returns the name for this type that closely resembles how it would be
     /// declared in WGSL.
@@ -241,6 +253,7 @@ class Array final : public Castable<Array, Type> {
     const uint32_t size_;
     const uint32_t stride_;
     const uint32_t implicit_stride_;
+    utils::UniqueVector<const GlobalVariable*, 4> referenced_overrides_;
 };
 
 }  // namespace tint::sem

src/tint/sem/variable.h

@@ -27,6 +27,7 @@
 #include "src/tint/sem/binding_point.h"
 #include "src/tint/sem/expression.h"
 #include "src/tint/sem/parameter_usage.h"
+#include "src/tint/utils/unique_vector.h"
 
 // Forward declarations
 namespace tint::ast {
@@ -182,11 +183,23 @@ class GlobalVariable final : public Castable<GlobalVariable, Variable> {
     /// @returns the location value for the parameter, if set
     std::optional<uint32_t> Location() const { return location_; }
 
+    /// Records that this variable (transitively) references the given override variable.
+    /// @param var the module-scope override variable
+    void AddTransitivelyReferencedOverride(const GlobalVariable* var) {
+        referenced_overrides_.Add(var);
+    }
+
+    /// @returns all transitively referenced override variables
+    const utils::UniqueVector<const GlobalVariable*, 4>& TransitivelyReferencedOverrides() const {
+        return referenced_overrides_;
+    }
+
   private:
     const sem::BindingPoint binding_point_;
 
     tint::OverrideId override_id_;
     std::optional<uint32_t> location_;
+    utils::UniqueVector<const GlobalVariable*, 4> referenced_overrides_;
 };
 
 /// Parameter is a function parameter