1 //===- CocoaConventions.h - Special handling of Cocoa conventions -*- C++ -*--// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file implements cocoa naming convention analysis. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "clang/Analysis/DomainSpecific/CocoaConventions.h" 14 #include "clang/AST/Decl.h" 15 #include "clang/AST/DeclObjC.h" 16 #include "clang/AST/Type.h" 17 #include "clang/Basic/CharInfo.h" 18 #include "llvm/ADT/StringExtras.h" 19 #include "llvm/Support/ErrorHandling.h" 20 21 using namespace clang; 22 using namespace ento; 23 24 bool cocoa::isRefType(QualType RetTy, StringRef Prefix, 25 StringRef Name) { 26 // Recursively walk the typedef stack, allowing typedefs of reference types. 27 while (const TypedefType *TD = RetTy->getAs<TypedefType>()) { 28 StringRef TDName = TD->getDecl()->getIdentifier()->getName(); 29 if (TDName.starts_with(Prefix) && TDName.ends_with("Ref")) 30 return true; 31 // XPC unfortunately uses CF-style function names, but aren't CF types. 32 if (TDName.starts_with("xpc_")) 33 return false; 34 RetTy = TD->getDecl()->getUnderlyingType(); 35 } 36 37 if (Name.empty()) 38 return false; 39 40 // Is the type void*? 41 const PointerType* PT = RetTy->castAs<PointerType>(); 42 if (!PT || !PT->getPointeeType().getUnqualifiedType()->isVoidType()) 43 return false; 44 45 // Does the name start with the prefix? 46 return Name.starts_with(Prefix); 47 } 48 49 /// Returns true when the passed-in type is a CF-style reference-counted 50 /// type from the DiskArbitration framework. 51 static bool isDiskArbitrationAPIRefType(QualType T) { 52 return cocoa::isRefType(T, "DADisk") || 53 cocoa::isRefType(T, "DADissenter") || 54 cocoa::isRefType(T, "DASessionRef"); 55 } 56 57 bool coreFoundation::isCFObjectRef(QualType T) { 58 return cocoa::isRefType(T, "CF") || // Core Foundation. 59 cocoa::isRefType(T, "CG") || // Core Graphics. 60 cocoa::isRefType(T, "CM") || // Core Media. 61 isDiskArbitrationAPIRefType(T); 62 } 63 64 65 bool cocoa::isCocoaObjectRef(QualType Ty) { 66 if (!Ty->isObjCObjectPointerType()) 67 return false; 68 69 const ObjCObjectPointerType *PT = Ty->getAs<ObjCObjectPointerType>(); 70 71 // Can be true for objects with the 'NSObject' attribute. 72 if (!PT) 73 return true; 74 75 // We assume that id<..>, id, Class, and Class<..> all represent tracked 76 // objects. 77 if (PT->isObjCIdType() || PT->isObjCQualifiedIdType() || 78 PT->isObjCClassType() || PT->isObjCQualifiedClassType()) 79 return true; 80 81 // Does the interface subclass NSObject? 82 // FIXME: We can memoize here if this gets too expensive. 83 const ObjCInterfaceDecl *ID = PT->getInterfaceDecl(); 84 85 // Assume that anything declared with a forward declaration and no 86 // @interface subclasses NSObject. 87 if (!ID->hasDefinition()) 88 return true; 89 90 for ( ; ID ; ID = ID->getSuperClass()) 91 if (ID->getIdentifier()->getName() == "NSObject") 92 return true; 93 94 return false; 95 } 96 97 bool coreFoundation::followsCreateRule(const FunctionDecl *fn) { 98 // For now, *just* base this on the function name, not on anything else. 99 100 const IdentifierInfo *ident = fn->getIdentifier(); 101 if (!ident) return false; 102 StringRef functionName = ident->getName(); 103 104 StringRef::iterator it = functionName.begin(); 105 StringRef::iterator start = it; 106 StringRef::iterator endI = functionName.end(); 107 108 while (true) { 109 // Scan for the start of 'create' or 'copy'. 110 for ( ; it != endI ; ++it) { 111 // Search for the first character. It can either be 'C' or 'c'. 112 char ch = *it; 113 if (ch == 'C' || ch == 'c') { 114 // Make sure this isn't something like 'recreate' or 'Scopy'. 115 if (ch == 'c' && it != start && isLetter(*(it - 1))) 116 continue; 117 118 ++it; 119 break; 120 } 121 } 122 123 // Did we hit the end of the string? If so, we didn't find a match. 124 if (it == endI) 125 return false; 126 127 // Scan for *lowercase* 'reate' or 'opy', followed by no lowercase 128 // character. 129 StringRef suffix = functionName.substr(it - start); 130 if (suffix.starts_with("reate")) { 131 it += 5; 132 } else if (suffix.starts_with("opy")) { 133 it += 3; 134 } else { 135 // Keep scanning. 136 continue; 137 } 138 139 if (it == endI || !isLowercase(*it)) 140 return true; 141 142 // If we matched a lowercase character, it isn't the end of the 143 // word. Keep scanning. 144 } 145 } 146