llvm-project/clang/lib/Basic/Attributes.cpp

#include "clang/Basic/Attributes.h"
#include "clang/Basic/IdentifierTable.h"
#include "llvm/ADT/StringSwitch.h"
using namespace clang;

int clang::hasAttribute(AttrSyntax Syntax, const IdentifierInfo *Scope,
                        const IdentifierInfo *Attr, const TargetInfo &Target,
                        const LangOptions &LangOpts) {
  StringRef Name = Attr->getName();
  // Normalize the attribute name, __foo__ becomes foo.
  if (Name.size() >= 4 && Name.startswith("__") && Name.endswith("__"))
    Name = Name.substr(2, Name.size() - 4);

#include "clang/Basic/AttrHasAttributeImpl.inc"

  return 0;
}