[clang] Implement resource binding type prefix mismatch diagnostic infrastructure (PR #97103)

[Joshua Batista via cfe-commits]

================
@@ -437,7 +453,409 @@ void SemaHLSL::handleShaderAttr(Decl *D, const ParsedAttr &AL) {
     D->addAttr(NewAttr);
 }
 
+struct RegisterBindingFlags {
+  bool Resource = false;
+  bool Udt = false;
+  bool Other = false;
+  bool Basic = false;
+
+  bool Srv = false;
+  bool Uav = false;
+  bool Cbv = false;
+  bool Sampler = false;
+
+  bool ContainsNumeric = false;
+  bool DefaultGlobals = false;
+};
+
+bool isDeclaredWithinCOrTBuffer(const Decl *decl) {
+  if (!decl)
+    return false;
+
+  // Traverse up the parent contexts
+  const DeclContext *context = decl->getDeclContext();
+  while (context) {
+    if (isa<HLSLBufferDecl>(context)) {
+      return true;
+    }
+    context = context->getParent();
+  }
+
+  return false;
+}
+
+const CXXRecordDecl *getRecordDeclFromVarDecl(VarDecl *VD) {
+  const Type *Ty = VD->getType()->getPointeeOrArrayElementType();
+  if (!Ty)
+    llvm_unreachable("Resource class must have an element type.");
+
+  if (const BuiltinType *BTy = dyn_cast<BuiltinType>(Ty)) {
+    return nullptr;
+  }
+
+  const CXXRecordDecl *TheRecordDecl = Ty->getAsCXXRecordDecl();
+  if (!TheRecordDecl)
+    llvm_unreachable("Resource class should have a resource type declaration.");
+
+  if (auto TDecl = dyn_cast<ClassTemplateSpecializationDecl>(TheRecordDecl))
+    TheRecordDecl = TDecl->getSpecializedTemplate()->getTemplatedDecl();
+  TheRecordDecl = TheRecordDecl->getCanonicalDecl();
+  return TheRecordDecl;
+}
+
+const HLSLResourceAttr *
+getHLSLResourceAttrFromEitherDecl(VarDecl *VD,
+                                  HLSLBufferDecl *CBufferOrTBuffer) {
+
+  if (VD) {
+    const CXXRecordDecl *TheRecordDecl = getRecordDeclFromVarDecl(VD);
+    if (!TheRecordDecl)
+      return nullptr;
+    const auto *Attr = TheRecordDecl->getAttr<HLSLResourceAttr>();
+    return Attr;
+  } else if (CBufferOrTBuffer) {
+    const auto *Attr = CBufferOrTBuffer->getAttr<HLSLResourceAttr>();
+    return Attr;
+  }
+  llvm_unreachable("one of the two conditions should be true.");
+  return nullptr;
+}
+
+void traverseType(QualType T, RegisterBindingFlags &r) {
+  if (T->isIntegralOrEnumerationType() || T->isFloatingType()) {
+    r.ContainsNumeric = true;
+    return;
+  } else if (const RecordType *RT = T->getAs<RecordType>()) {
+    RecordDecl *SubRD = RT->getDecl();
+    if (auto TDecl = dyn_cast<ClassTemplateSpecializationDecl>(SubRD)) {
+      auto TheRecordDecl = TDecl->getSpecializedTemplate()->getTemplatedDecl();
+      TheRecordDecl = TheRecordDecl->getCanonicalDecl();
+      const auto *Attr = TheRecordDecl->getAttr<HLSLResourceAttr>();
+      llvm::hlsl::ResourceClass DeclResourceClass = Attr->getResourceClass();
+      switch (DeclResourceClass) {
+      case llvm::hlsl::ResourceClass::SRV: {
+        r.Srv = true;
+        break;
+      }
+      case llvm::hlsl::ResourceClass::UAV: {
+        r.Uav = true;
+        break;
+      }
+      case llvm::hlsl::ResourceClass::CBuffer: {
+        r.Cbv = true;
+        break;
+      }
+      case llvm::hlsl::ResourceClass::Sampler: {
+        r.Sampler = true;
+        break;
+      }
+      }
+    }
+
+    else if (SubRD->isCompleteDefinition()) {
+      for (auto Field : SubRD->fields()) {
+        QualType T = Field->getType();
+        traverseType(T, r);
+      }
+    }
+  }
+}
+
+void setResourceClassFlagsFromRecordDecl(RegisterBindingFlags &r,
+                                         const RecordDecl *RD) {
+  if (!RD)
+    return;
+
+  if (RD->isCompleteDefinition()) {
+    for (auto Field : RD->fields()) {
+      QualType T = Field->getType();
+      traverseType(T, r);
+    }
+  }
+}
+
+RegisterBindingFlags HLSLFillRegisterBindingFlags(Sema &S, Decl *D) {
+  RegisterBindingFlags r;
+  if (!isDeclaredWithinCOrTBuffer(D)) {
+    // make sure the type is a basic / numeric type
+    if (VarDecl *v = dyn_cast<VarDecl>(D)) {
+      QualType t = v->getType();
+      // a numeric variable will inevitably end up in $Globals buffer
+      if (t->isIntegralType(S.getASTContext()) || t->isFloatingType())
+        r.DefaultGlobals = true;
+    }
+  }
+  // Cbuffers and Tbuffers are HLSLBufferDecl types
+  HLSLBufferDecl *CBufferOrTBuffer = dyn_cast<HLSLBufferDecl>(D);
+  // Samplers, UAVs, and SRVs are VarDecl types
+  VarDecl *VD = dyn_cast<VarDecl>(D);
+
+  if (CBufferOrTBuffer) {
+    r.Resource = true;
+    if (CBufferOrTBuffer->isCBuffer())
+      r.Cbv = true;
+    else
+      r.Srv = true;
+  } else if (VD) {
+    const HLSLResourceAttr *res_attr =
+        getHLSLResourceAttrFromEitherDecl(VD, CBufferOrTBuffer);
+    if (res_attr) {
+      llvm::hlsl::ResourceClass DeclResourceClass =
+          res_attr->getResourceClass();
+      r.Resource = true;
+      switch (DeclResourceClass) {
+      case llvm::hlsl::ResourceClass::SRV: {
+        r.Srv = true;
+        break;
+      }
+      case llvm::hlsl::ResourceClass::UAV: {
+        r.Uav = true;
+        break;
+      }
+      case llvm::hlsl::ResourceClass::CBuffer: {
+        r.Cbv = true;
+        break;
+      }
+      case llvm::hlsl::ResourceClass::Sampler: {
+        r.Sampler = true;
+        break;
+      }
+      }
+    } else {
+      if (VD->getType()->isBuiltinType())
+        r.Basic = true;
+      else if (VD->getType()->isAggregateType()) {
+        r.Udt = true;
+        QualType VarType = VD->getType();
+        if (const RecordType *RT = VarType->getAs<RecordType>()) {
+          const RecordDecl *RD = RT->getDecl();
+          // recurse through members, set appropriate resource class flags.
+          setResourceClassFlagsFromRecordDecl(r, RD);
+        }
+      } else
+        r.Other = true;
+    }
+  } else {
+    llvm_unreachable("unknown decl type");
----------------
bob80905 wrote:

Turns out that there's an assert for this in the caller function before this function is called, so this is impossible to reach, and I'll remove it.

https://github.com/llvm/llvm-project/pull/97103