[clang] [HLSL] Add implicit resource element type concepts to AST (PR #112600)

[Chris B via cfe-commits]

================
@@ -483,10 +581,102 @@ static BuiltinTypeDeclBuilder setupBufferType(CXXRecordDecl *Decl, Sema &S,
       .addDefaultHandleConstructor(S, RC);
 }
 
+BinaryOperator *constructSizeOfLEQ16Expr(ASTContext &Context,
+                                         SourceLocation NameLoc,
+                                         TemplateTypeParmDecl *T) {
+  // Obtain the QualType for 'unsigned long'
+  QualType UnsignedLongType = Context.UnsignedLongTy;
+
+  // Create a QualType that points to this TemplateTypeParmDecl
+  QualType TType = Context.getTypeDeclType(T);
+
+  // Create a TypeSourceInfo for the template type parameter 'T'
+  TypeSourceInfo *TTypeSourceInfo =
+      Context.getTrivialTypeSourceInfo(TType, NameLoc);
+
+  UnaryExprOrTypeTraitExpr *sizeOfExpr = new (Context) UnaryExprOrTypeTraitExpr(
+      UETT_SizeOf, TTypeSourceInfo, UnsignedLongType, NameLoc, NameLoc);
+
+  // Create an IntegerLiteral for the value '16' with size type
+  QualType SizeType = Context.getSizeType();
+  llvm::APInt SizeValue = llvm::APInt(Context.getTypeSize(SizeType), 16);
+  IntegerLiteral *SizeLiteral =
+      new (Context) IntegerLiteral(Context, SizeValue, SizeType, NameLoc);
+
+  QualType BoolTy = Context.BoolTy;
+
+  BinaryOperator *binaryOperator =
+      BinaryOperator::Create(Context, sizeOfExpr, // Left-hand side expression
+                             SizeLiteral,         // Right-hand side expression
+                             BO_LE,               // Binary operator kind (<=)
+                             BoolTy,              // Result type (bool)
+                             VK_LValue,           // Value kind
+                             OK_Ordinary,         // Object kind
+                             NameLoc,             // Source location of operator
+                             FPOptionsOverride());
+
+  return binaryOperator;
+}
+
+Expr *constructTypedBufferConstraintExpr(Sema &S, SourceLocation NameLoc,
+                                         TemplateTypeParmDecl *T) {
+  ASTContext &Context = S.getASTContext();
+
+  // first get the "sizeof(T) <= 16" expression, as a binary operator
+  BinaryOperator *SizeOfLEQ16 = constructSizeOfLEQ16Expr(Context, NameLoc, T);
+  // TODO: add the '__builtin_hlsl_is_line_vector_layout_compatible' builtin
+  // and return a binary operator that evaluates the builtin on the given
+  // template type parameter 'T'
+  return SizeOfLEQ16;
+}
+
+ConceptDecl *constructTypedBufferConceptDecl(Sema &S) {
+  DeclContext *DC = S.CurContext;
----------------
llvm-beanz wrote:

Do we want this to be Sema's current context, or the HLSL namespace context? My guess is the later.
It probably doesn't matter too much, but it would be nice to make sure we're not injecting AST nodes into the top-level declaration context or a user-defined context.

https://github.com/llvm/llvm-project/pull/112600