Split BindingArray validation from CheckType

Move binding array validation to a CheckBindingArray helper.

Change-Id: I2c33018e647d27cfc3dd758085a9961ec8d9c92a
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/320664
Commit-Queue: dan sinclair <dsinclair@chromium.org>
Reviewed-by: James Price <jrprice@google.com>

src/tint/lang/core/ir/structural_validator.cc

diff --git a/src/tint/lang/core/ir/structural_validator.cc b/src/tint/lang/core/ir/structural_validator.cc
index e659852..4d58242 100644
--- a/src/tint/lang/core/ir/structural_validator.cc
+++ b/src/tint/lang/core/ir/structural_validator.cc
@@ -704,31 +704,7 @@
                 return CheckSubgroupMatrix(m, diag, addrspace);
             },
             [&](const core::type::BindingArray* t) {
-                if (!t->Count()->Is<core::type::ConstantArrayCount>()) {
-                    diag() << "binding_array count must be a constant expression";
-                    return false;
-                }
-
-                auto count = t->Count()->As<core::type::ConstantArrayCount>()->value;
-                if (count == 0) {
-                    diag() << "binding array requires a constant array size > 0";
-                    return false;
-                }
-
-                if (!(addrspace == AddressSpace::kUndefined ||
-                      addrspace == AddressSpace::kHandle) &&
-                    !ir_.properties.Contains(Property::kAllowMslEntryPointInterface)) {
-                    diag() << "invalid address space for binding_array : " << addrspace;
-                    return false;
-                }
-
-                if (!ir_.properties.Contains(Property::kAllowNonCoreTypes)) {
-                    if (!t->ElemType()->Is<core::type::SampledTexture>()) {
-                        diag() << "binding_array element type must be a sampled texture type";
-                        return false;
-                    }
-                }
-                return true;
+                return CheckBindingArray(t, diag, addrspace);
             },
             [&](const core::type::Buffer*) {
                 if (!ir_.properties.Contains(Property::kAllowBufferTypes)) {
@@ -797,6 +773,35 @@
     }
 }
 
+bool Structural::CheckBindingArray(const core::type::BindingArray* ba,
+                                   std::function<diag::Diagnostic&()>& diag,
+                                   core::AddressSpace addrspace) {
+    if (!ba->Count()->Is<core::type::ConstantArrayCount>()) {
+        diag() << "binding_array count must be a constant expression";
+        return false;
+    }
+
+    auto count = ba->Count()->As<core::type::ConstantArrayCount>()->value;
+    if (count == 0) {
+        diag() << "binding array requires a constant array size > 0";
+        return false;
+    }
+
+    if (!(addrspace == AddressSpace::kUndefined || addrspace == AddressSpace::kHandle) &&
+        !ir_.properties.Contains(Property::kAllowMslEntryPointInterface)) {
+        diag() << "invalid address space for binding_array : " << addrspace;
+        return false;
+    }
+
+    if (!ir_.properties.Contains(Property::kAllowNonCoreTypes)) {
+        if (!ba->ElemType()->Is<core::type::SampledTexture>()) {
+            diag() << "binding_array element type must be a sampled texture type";
+            return false;
+        }
+    }
+    return true;
+}
+
 bool Structural::CheckSubgroupMatrix(const core::type::SubgroupMatrix* m,
                                      std::function<diag::Diagnostic&()>& diag,
                                      core::AddressSpace addrspace) {

src/tint/lang/core/ir/structural_validator.h

diff --git a/src/tint/lang/core/ir/structural_validator.h b/src/tint/lang/core/ir/structural_validator.h
index b429027..e051458 100644
--- a/src/tint/lang/core/ir/structural_validator.h
+++ b/src/tint/lang/core/ir/structural_validator.h
@@ -380,6 +380,13 @@
     bool CheckSubgroupMatrix(const core::type::SubgroupMatrix* m,
                              std::function<diag::Diagnostic&()>& diag,
                              core::AddressSpace addrspace);
+    /// Checks that `ba` is a valid binding array
+    /// @param ba the binding array
+    /// @param diag a function that creates an error diagnostic for the source of the type
+    /// @param addrspace the address space of the root type
+    bool CheckBindingArray(const core::type::BindingArray* ba,
+                           std::function<diag::Diagnostic&()>& diag,
+                           core::AddressSpace addrspace);
 
     /// Checks that 8-bit types are permitted
     /// @param diag a function that creates an error diagnostic for the source of the type