text: //===- CocoaConventions.h - Special handling of Cocoa conventions -*- C++ -*--//
  //
  //                     The LLVM Compiler Infrastructure
  //
  // This file is distributed under the University of Illinois Open Source
  // License. See LICENSE.TXT for details.
  //
  //===----------------------------------------------------------------------===//
  //
  // This file implements cocoa naming convention analysis. 
  //
  //===----------------------------------------------------------------------===//
  
  #include "clang/Analysis/DomainSpecific/CocoaConventions.h"
  #include "clang/AST/Decl.h"
  #include "clang/AST/DeclObjC.h"
  #include "clang/AST/Type.h"
  #include "clang/Basic/CharInfo.h"
  #include "llvm/ADT/StringExtras.h"
  #include "llvm/Support/ErrorHandling.h"
  
  using namespace clang;
  using namespace ento;
  
  bool cocoa::isRefType(QualType RetTy, StringRef Prefix,
                        StringRef Name) {
    // Recursively walk the typedef stack, allowing typedefs of reference types.
    while (const TypedefType *TD = RetTy->getAs<TypedefType>()) {
      StringRef TDName = TD->getDecl()->getIdentifier()->getName();
      if (TDName.startswith(Prefix) && TDName.endswith("Ref"))
        return true;
      // XPC unfortunately uses CF-style function names, but aren't CF types.
      if (TDName.startswith("xpc_"))
        return false;
      RetTy = TD->getDecl()->getUnderlyingType();
    }
    
    if (Name.empty())
      return false;
    
    // Is the type void*?
    const PointerType* PT = RetTy->getAs<PointerType>();
    if (!(PT->getPointeeType().getUnqualifiedType()->isVoidType()))
      return false;
    
    // Does the name start with the prefix?
    return Name.startswith(Prefix);
  }
  
  bool coreFoundation::isCFObjectRef(QualType T) {
    return cocoa::isRefType(T, "CF") || // Core Foundation.
           cocoa::isRefType(T, "CG") || // Core Graphics.
           cocoa::isRefType(T, "DADisk") || // Disk Arbitration API.
           cocoa::isRefType(T, "DADissenter") ||
           cocoa::isRefType(T, "DASessionRef");
  }
  
  
  bool cocoa::isCocoaObjectRef(QualType Ty) {
    if (!Ty->isObjCObjectPointerType())
      return false;
    
    const ObjCObjectPointerType *PT = Ty->getAs<ObjCObjectPointerType>();
    
    // Can be true for objects with the 'NSObject' attribute.
    if (!PT)
      return true;
    
    // We assume that id<..>, id, Class, and Class<..> all represent tracked
    // objects.
    if (PT->isObjCIdType() || PT->isObjCQualifiedIdType() ||
        PT->isObjCClassType() || PT->isObjCQualifiedClassType())
      return true;
    
    // Does the interface subclass NSObject?
    // FIXME: We can memoize here if this gets too expensive.
    const ObjCInterfaceDecl *ID = PT->getInterfaceDecl();
    
    // Assume that anything declared with a forward declaration and no
    // @interface subclasses NSObject.
    if (!ID->hasDefinition())
      return true;
    
    for ( ; ID ; ID = ID->getSuperClass())
      if (ID->getIdentifier()->getName() == "NSObject")
        return true;
    
    return false;
  }
  
  bool coreFoundation::followsCreateRule(const FunctionDecl *fn) {
    // For now, *just* base this on the function name, not on anything else.
  
    const IdentifierInfo *ident = fn->getIdentifier();
    if (!ident) return false;
    StringRef functionName = ident->getName();
    
    StringRef::iterator it = functionName.begin();
    StringRef::iterator start = it;
    StringRef::iterator endI = functionName.end();
      
    while (true) {
      // Scan for the start of 'create' or 'copy'.
      for ( ; it != endI ; ++it) {
        // Search for the first character.  It can either be 'C' or 'c'.
        char ch = *it;
        if (ch == 'C' || ch == 'c') {
          // Make sure this isn't something like 'recreate' or 'Scopy'.
          if (ch == 'c' && it != start && isLetter(*(it - 1)))
            continue;
  
          ++it;
          break;
        }
      }
  
      // Did we hit the end of the string?  If so, we didn't find a match.
      if (it == endI)
        return false;
      
      // Scan for *lowercase* 'reate' or 'opy', followed by no lowercase
      // character.
      StringRef suffix = functionName.substr(it - start);
      if (suffix.startswith("reate")) {
        it += 5;
      }
      else if (suffix.startswith("opy")) {
        it += 3;
      } else {
        // Keep scanning.
        continue;
      }
      
      if (it == endI || !isLowercase(*it))
        return true;
    
      // If we matched a lowercase character, it isn't the end of the
      // word.  Keep scanning.
    }
  }
  