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