[clang] Implement resource binding type prefix mismatch errors (PR #87578)

[Justin Bogner via cfe-commits]

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@@ -7367,8 +7367,72 @@ static void handleHLSLResourceBindingAttr(Sema &S, Decl *D,
     return;
   }
 
-  // FIXME: check reg type match decl. Issue
-  // https://github.com/llvm/llvm-project/issues/57886.
+  VarDecl *VD = dyn_cast<VarDecl>(D);
+  HLSLBufferDecl *BD = dyn_cast<HLSLBufferDecl>(D);
+
+  if (VD || BD) {
+    llvm::hlsl::ResourceClass RC;
+    std::string varTy = "";
+    if (VD) {
+
+      const Type *Ty = VD->getType()->getPointeeOrArrayElementType();
+      if (!Ty)
+        return;
+      QualType t = ((ElaboratedType *)Ty)->getNamedType();
+      const CXXRecordDecl *RD = Ty->getAsCXXRecordDecl();
+      if (!RD)
+        return;
+
+      if (auto TDecl = dyn_cast<ClassTemplateSpecializationDecl>(RD))
+        RD = TDecl->getSpecializedTemplate()->getTemplatedDecl();
+      RD = RD->getCanonicalDecl();
+      const auto *Attr = RD->getAttr<HLSLResourceAttr>();
+      if (!Attr)
+        return;
+
+      RC = Attr->getResourceClass();
+      varTy = RD->getNameAsString();
+    } else {
+      if (BD->isCBuffer()) {
+        RC = llvm::hlsl::ResourceClass::CBuffer;
+        varTy = "cbuffer";
+      } else {
+        RC = llvm::hlsl::ResourceClass::CBuffer;
+        varTy = "tbuffer";
+      }
+    }
+    switch (RC) {
+    case llvm::hlsl::ResourceClass::SRV: {
+      if (Slot[0] != 't')
+        S.Diag(ArgLoc, diag::err_hlsl_mismatching_register_type_and_name)
+            << Slot.substr(0, 1) << varTy << "t";
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bogner wrote:

I think clang generally prefers using "select" in the diagnostic rather than passing in raw strings like "t" here.

https://github.com/llvm/llvm-project/pull/87578