1 files changed, 577 insertions, 0 deletions
diff --git a/contrib/llvm/tools/clang/lib/Checker/BasicObjCFoundationChecks.cpp b/contrib/llvm/tools/clang/lib/Checker/BasicObjCFoundationChecks.cpp
new file mode 100644
index 0000000..b852e2a
--- /dev/null
+++ b/contrib/llvm/tools/clang/lib/Checker/BasicObjCFoundationChecks.cpp
@@ -0,0 +1,577 @@
+//== BasicObjCFoundationChecks.cpp - Simple Apple-Foundation checks -*- C++ -*--
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file defines BasicObjCFoundationChecks, a class that encapsulates
+//  a set of simple checks to run on Objective-C code using Apple's Foundation
+//  classes.
+//
+//===----------------------------------------------------------------------===//
+
+#include "BasicObjCFoundationChecks.h"
+
+#include "clang/Checker/PathSensitive/ExplodedGraph.h"
+#include "clang/Checker/PathSensitive/GRSimpleAPICheck.h"
+#include "clang/Checker/PathSensitive/GRExprEngine.h"
+#include "clang/Checker/PathSensitive/GRState.h"
+#include "clang/Checker/BugReporter/BugType.h"
+#include "clang/Checker/PathSensitive/MemRegion.h"
+#include "clang/Checker/PathSensitive/CheckerVisitor.h"
+#include "clang/Checker/Checkers/LocalCheckers.h"
+#include "clang/AST/DeclObjC.h"
+#include "clang/AST/Expr.h"
+#include "clang/AST/ExprObjC.h"
+#include "clang/AST/ASTContext.h"
+
+using namespace clang;
+
+static const ObjCInterfaceType* GetReceiverType(const ObjCMessageExpr* ME) {
+  QualType T;
+  switch (ME->getReceiverKind()) {
+  case ObjCMessageExpr::Instance:
+    T = ME->getInstanceReceiver()->getType();
+    break;
+
+  case ObjCMessageExpr::SuperInstance:
+    T = ME->getSuperType();
+    break;
+
+  case ObjCMessageExpr::Class:
+  case ObjCMessageExpr::SuperClass:
+    return 0;
+  }
+
+  if (const ObjCObjectPointerType *PT = T->getAs<ObjCObjectPointerType>())
+    return PT->getInterfaceType();
+
+  return NULL;
+}
+
+static const char* GetReceiverNameType(const ObjCMessageExpr* ME) {
+  if (const ObjCInterfaceType *ReceiverType = GetReceiverType(ME))
+    return ReceiverType->getDecl()->getIdentifier()->getNameStart();
+  return NULL;
+}
+
+namespace {
+
+class APIMisuse : public BugType {
+public:
+  APIMisuse(const char* name) : BugType(name, "API Misuse (Apple)") {}
+};
+
+class BasicObjCFoundationChecks : public GRSimpleAPICheck {
+  APIMisuse *BT;
+  BugReporter& BR;
+  ASTContext &Ctx;
+
+  bool isNSString(const ObjCInterfaceType *T, llvm::StringRef suffix);
+  bool AuditNSString(ExplodedNode* N, const ObjCMessageExpr* ME);
+
+  void Warn(ExplodedNode* N, const Expr* E, const std::string& s);
+  void WarnNilArg(ExplodedNode* N, const Expr* E);
+
+  bool CheckNilArg(ExplodedNode* N, unsigned Arg);
+
+public:
+  BasicObjCFoundationChecks(ASTContext& ctx, BugReporter& br)
+    : BT(0), BR(br), Ctx(ctx) {}
+
+  bool Audit(ExplodedNode* N, GRStateManager&);
+
+private:
+  void WarnNilArg(ExplodedNode* N, const ObjCMessageExpr* ME, unsigned Arg) {
+    std::string sbuf;
+    llvm::raw_string_ostream os(sbuf);
+    os << "Argument to '" << GetReceiverNameType(ME) << "' method '"
+       << ME->getSelector().getAsString() << "' cannot be nil.";
+
+    // Lazily create the BugType object for NilArg.  This will be owned
+    // by the BugReporter object 'BR' once we call BR.EmitWarning.
+    if (!BT) BT = new APIMisuse("nil argument");
+
+    RangedBugReport *R = new RangedBugReport(*BT, os.str(), N);
+    R->addRange(ME->getArg(Arg)->getSourceRange());
+    BR.EmitReport(R);
+  }
+};
+
+} // end anonymous namespace
+
+
+GRSimpleAPICheck*
+clang::CreateBasicObjCFoundationChecks(ASTContext& Ctx, BugReporter& BR) {
+  return new BasicObjCFoundationChecks(Ctx, BR);
+}
+
+
+
+bool BasicObjCFoundationChecks::Audit(ExplodedNode* N,
+                                      GRStateManager&) {
+
+  const ObjCMessageExpr* ME =
+    cast<ObjCMessageExpr>(cast<PostStmt>(N->getLocation()).getStmt());
+
+  const ObjCInterfaceType *ReceiverType = GetReceiverType(ME);
+
+  if (!ReceiverType)
+    return false;
+
+  if (isNSString(ReceiverType,
+                 ReceiverType->getDecl()->getIdentifier()->getName()))
+    return AuditNSString(N, ME);
+
+  return false;
+}
+
+static inline bool isNil(SVal X) {
+  return isa<loc::ConcreteInt>(X);
+}
+
+//===----------------------------------------------------------------------===//
+// Error reporting.
+//===----------------------------------------------------------------------===//
+
+bool BasicObjCFoundationChecks::CheckNilArg(ExplodedNode* N, unsigned Arg) {
+  const ObjCMessageExpr* ME =
+    cast<ObjCMessageExpr>(cast<PostStmt>(N->getLocation()).getStmt());
+
+  const Expr * E = ME->getArg(Arg);
+
+  if (isNil(N->getState()->getSVal(E))) {
+    WarnNilArg(N, ME, Arg);
+    return true;
+  }
+
+  return false;
+}
+
+//===----------------------------------------------------------------------===//
+// NSString checking.
+//===----------------------------------------------------------------------===//
+
+bool BasicObjCFoundationChecks::isNSString(const ObjCInterfaceType *T,
+                                           llvm::StringRef ClassName) {
+  return ClassName == "NSString" || ClassName == "NSMutableString";
+}
+
+bool BasicObjCFoundationChecks::AuditNSString(ExplodedNode* N,
+                                              const ObjCMessageExpr* ME) {
+
+  Selector S = ME->getSelector();
+
+  if (S.isUnarySelector())
+    return false;
+
+  // FIXME: This is going to be really slow doing these checks with
+  //  lexical comparisons.
+
+  std::string NameStr = S.getAsString();
+  llvm::StringRef Name(NameStr);
+  assert(!Name.empty());
+
+  // FIXME: Checking for initWithFormat: will not work in most cases
+  //  yet because [NSString alloc] returns id, not NSString*.  We will
+  //  need support for tracking expected-type information in the analyzer
+  //  to find these errors.
+  if (Name == "caseInsensitiveCompare:" ||
+      Name == "compare:" ||
+      Name == "compare:options:" ||
+      Name == "compare:options:range:" ||
+      Name == "compare:options:range:locale:" ||
+      Name == "componentsSeparatedByCharactersInSet:" ||
+      Name == "initWithFormat:")
+    return CheckNilArg(N, 0);
+
+  return false;
+}
+
+//===----------------------------------------------------------------------===//
+// Error reporting.
+//===----------------------------------------------------------------------===//
+
+namespace {
+
+class AuditCFNumberCreate : public GRSimpleAPICheck {
+  APIMisuse* BT;
+
+  // FIXME: Either this should be refactored into GRSimpleAPICheck, or
+  //   it should always be passed with a call to Audit.  The latter
+  //   approach makes this class more stateless.
+  ASTContext& Ctx;
+  IdentifierInfo* II;
+  BugReporter& BR;
+
+public:
+  AuditCFNumberCreate(ASTContext& ctx, BugReporter& br)
+  : BT(0), Ctx(ctx), II(&Ctx.Idents.get("CFNumberCreate")), BR(br){}
+
+  ~AuditCFNumberCreate() {}
+
+  bool Audit(ExplodedNode* N, GRStateManager&);
+
+private:
+  void AddError(const TypedRegion* R, const Expr* Ex, ExplodedNode *N,
+                uint64_t SourceSize, uint64_t TargetSize, uint64_t NumberKind);
+};
+} // end anonymous namespace
+
+enum CFNumberType {
+  kCFNumberSInt8Type = 1,
+  kCFNumberSInt16Type = 2,
+  kCFNumberSInt32Type = 3,
+  kCFNumberSInt64Type = 4,
+  kCFNumberFloat32Type = 5,
+  kCFNumberFloat64Type = 6,
+  kCFNumberCharType = 7,
+  kCFNumberShortType = 8,
+  kCFNumberIntType = 9,
+  kCFNumberLongType = 10,
+  kCFNumberLongLongType = 11,
+  kCFNumberFloatType = 12,
+  kCFNumberDoubleType = 13,
+  kCFNumberCFIndexType = 14,
+  kCFNumberNSIntegerType = 15,
+  kCFNumberCGFloatType = 16
+};
+
+namespace {
+  template<typename T>
+  class Optional {
+    bool IsKnown;
+    T Val;
+  public:
+    Optional() : IsKnown(false), Val(0) {}
+    Optional(const T& val) : IsKnown(true), Val(val) {}
+
+    bool isKnown() const { return IsKnown; }
+
+    const T& getValue() const {
+      assert (isKnown());
+      return Val;
+    }
+
+    operator const T&() const {
+      return getValue();
+    }
+  };
+}
+
+static Optional<uint64_t> GetCFNumberSize(ASTContext& Ctx, uint64_t i) {
+  static const unsigned char FixedSize[] = { 8, 16, 32, 64, 32, 64 };
+
+  if (i < kCFNumberCharType)
+    return FixedSize[i-1];
+
+  QualType T;
+
+  switch (i) {
+    case kCFNumberCharType:     T = Ctx.CharTy;     break;
+    case kCFNumberShortType:    T = Ctx.ShortTy;    break;
+    case kCFNumberIntType:      T = Ctx.IntTy;      break;
+    case kCFNumberLongType:     T = Ctx.LongTy;     break;
+    case kCFNumberLongLongType: T = Ctx.LongLongTy; break;
+    case kCFNumberFloatType:    T = Ctx.FloatTy;    break;
+    case kCFNumberDoubleType:   T = Ctx.DoubleTy;   break;
+    case kCFNumberCFIndexType:
+    case kCFNumberNSIntegerType:
+    case kCFNumberCGFloatType:
+      // FIXME: We need a way to map from names to Type*.
+    default:
+      return Optional<uint64_t>();
+  }
+
+  return Ctx.getTypeSize(T);
+}
+
+#if 0
+static const char* GetCFNumberTypeStr(uint64_t i) {
+  static const char* Names[] = {
+    "kCFNumberSInt8Type",
+    "kCFNumberSInt16Type",
+    "kCFNumberSInt32Type",
+    "kCFNumberSInt64Type",
+    "kCFNumberFloat32Type",
+    "kCFNumberFloat64Type",
+    "kCFNumberCharType",
+    "kCFNumberShortType",
+    "kCFNumberIntType",
+    "kCFNumberLongType",
+    "kCFNumberLongLongType",
+    "kCFNumberFloatType",
+    "kCFNumberDoubleType",
+    "kCFNumberCFIndexType",
+    "kCFNumberNSIntegerType",
+    "kCFNumberCGFloatType"
+  };
+
+  return i <= kCFNumberCGFloatType ? Names[i-1] : "Invalid CFNumberType";
+}
+#endif
+
+bool AuditCFNumberCreate::Audit(ExplodedNode* N,GRStateManager&){
+  const CallExpr* CE =
+    cast<CallExpr>(cast<PostStmt>(N->getLocation()).getStmt());
+  const Expr* Callee = CE->getCallee();
+  SVal CallV = N->getState()->getSVal(Callee);
+  const FunctionDecl* FD = CallV.getAsFunctionDecl();
+
+  if (!FD || FD->getIdentifier() != II || CE->getNumArgs()!=3)
+    return false;
+
+  // Get the value of the "theType" argument.
+  SVal TheTypeVal = N->getState()->getSVal(CE->getArg(1));
+
+    // FIXME: We really should allow ranges of valid theType values, and
+    //   bifurcate the state appropriately.
+  nonloc::ConcreteInt* V = dyn_cast<nonloc::ConcreteInt>(&TheTypeVal);
+
+  if (!V)
+    return false;
+
+  uint64_t NumberKind = V->getValue().getLimitedValue();
+  Optional<uint64_t> TargetSize = GetCFNumberSize(Ctx, NumberKind);
+
+  // FIXME: In some cases we can emit an error.
+  if (!TargetSize.isKnown())
+    return false;
+
+  // Look at the value of the integer being passed by reference.  Essentially
+  // we want to catch cases where the value passed in is not equal to the
+  // size of the type being created.
+  SVal TheValueExpr = N->getState()->getSVal(CE->getArg(2));
+
+  // FIXME: Eventually we should handle arbitrary locations.  We can do this
+  //  by having an enhanced memory model that does low-level typing.
+  loc::MemRegionVal* LV = dyn_cast<loc::MemRegionVal>(&TheValueExpr);
+
+  if (!LV)
+    return false;
+
+  const TypedRegion* R = dyn_cast<TypedRegion>(LV->StripCasts());
+
+  if (!R)
+    return false;
+
+  QualType T = Ctx.getCanonicalType(R->getValueType(Ctx));
+
+  // FIXME: If the pointee isn't an integer type, should we flag a warning?
+  //  People can do weird stuff with pointers.
+
+  if (!T->isIntegerType())
+    return false;
+
+  uint64_t SourceSize = Ctx.getTypeSize(T);
+
+  // CHECK: is SourceSize == TargetSize
+
+  if (SourceSize == TargetSize)
+    return false;
+
+  AddError(R, CE->getArg(2), N, SourceSize, TargetSize, NumberKind);
+
+  // FIXME: We can actually create an abstract "CFNumber" object that has
+  //  the bits initialized to the provided values.
+  return SourceSize < TargetSize;
+}
+
+void AuditCFNumberCreate::AddError(const TypedRegion* R, const Expr* Ex,
+                                   ExplodedNode *N,
+                                   uint64_t SourceSize, uint64_t TargetSize,
+                                   uint64_t NumberKind) {
+
+  std::string sbuf;
+  llvm::raw_string_ostream os(sbuf);
+
+  os << (SourceSize == 8 ? "An " : "A ")
+     << SourceSize << " bit integer is used to initialize a CFNumber "
+        "object that represents "
+     << (TargetSize == 8 ? "an " : "a ")
+     << TargetSize << " bit integer. ";
+
+  if (SourceSize < TargetSize)
+    os << (TargetSize - SourceSize)
+       << " bits of the CFNumber value will be garbage." ;
+  else
+    os << (SourceSize - TargetSize)
+       << " bits of the input integer will be lost.";
+
+  // Lazily create the BugType object.  This will be owned
+  // by the BugReporter object 'BR' once we call BR.EmitWarning.
+  if (!BT) BT = new APIMisuse("Bad use of CFNumberCreate");
+  RangedBugReport *report = new RangedBugReport(*BT, os.str(), N);
+  report->addRange(Ex->getSourceRange());
+  BR.EmitReport(report);
+}
+
+GRSimpleAPICheck*
+clang::CreateAuditCFNumberCreate(ASTContext& Ctx, BugReporter& BR) {
+  return new AuditCFNumberCreate(Ctx, BR);
+}
+
+//===----------------------------------------------------------------------===//
+// CFRetain/CFRelease auditing for null arguments.
+//===----------------------------------------------------------------------===//
+
+namespace {
+class AuditCFRetainRelease : public GRSimpleAPICheck {
+  APIMisuse *BT;
+
+  // FIXME: Either this should be refactored into GRSimpleAPICheck, or
+  //   it should always be passed with a call to Audit.  The latter
+  //   approach makes this class more stateless.
+  ASTContext& Ctx;
+  IdentifierInfo *Retain, *Release;
+  BugReporter& BR;
+
+public:
+  AuditCFRetainRelease(ASTContext& ctx, BugReporter& br)
+  : BT(0), Ctx(ctx),
+    Retain(&Ctx.Idents.get("CFRetain")), Release(&Ctx.Idents.get("CFRelease")),
+    BR(br){}
+
+  ~AuditCFRetainRelease() {}
+
+  bool Audit(ExplodedNode* N, GRStateManager&);
+};
+} // end anonymous namespace
+
+
+bool AuditCFRetainRelease::Audit(ExplodedNode* N, GRStateManager&) {
+  const CallExpr* CE = cast<CallExpr>(cast<PostStmt>(N->getLocation()).getStmt());
+
+  // If the CallExpr doesn't have exactly 1 argument just give up checking.
+  if (CE->getNumArgs() != 1)
+    return false;
+
+  // Check if we called CFRetain/CFRelease.
+  const GRState* state = N->getState();
+  SVal X = state->getSVal(CE->getCallee());
+  const FunctionDecl* FD = X.getAsFunctionDecl();
+
+  if (!FD)
+    return false;
+
+  const IdentifierInfo *FuncII = FD->getIdentifier();
+  if (!(FuncII == Retain || FuncII == Release))
+    return false;
+
+  // Finally, check if the argument is NULL.
+  // FIXME: We should be able to bifurcate the state here, as a successful
+  // check will result in the value not being NULL afterwards.
+  // FIXME: Need a way to register vistors for the BugReporter.  Would like
+  // to benefit from the same diagnostics that regular null dereference
+  // reporting has.
+  if (state->getStateManager().isEqual(state, CE->getArg(0), 0)) {
+    if (!BT)
+      BT = new APIMisuse("null passed to CFRetain/CFRelease");
+
+    const char *description = (FuncII == Retain)
+                            ? "Null pointer argument in call to CFRetain"
+                            : "Null pointer argument in call to CFRelease";
+
+    RangedBugReport *report = new RangedBugReport(*BT, description, N);
+    report->addRange(CE->getArg(0)->getSourceRange());
+    BR.EmitReport(report);
+    return true;
+  }
+
+  return false;
+}
+
+
+GRSimpleAPICheck*
+clang::CreateAuditCFRetainRelease(ASTContext& Ctx, BugReporter& BR) {
+  return new AuditCFRetainRelease(Ctx, BR);
+}
+
+//===----------------------------------------------------------------------===//
+// Check for sending 'retain', 'release', or 'autorelease' directly to a Class.
+//===----------------------------------------------------------------------===//
+
+namespace {
+class ClassReleaseChecker :
+    public CheckerVisitor<ClassReleaseChecker> {
+  Selector releaseS;
+  Selector retainS;
+  Selector autoreleaseS;
+  Selector drainS;
+  BugType *BT;
+public:
+  ClassReleaseChecker(ASTContext &Ctx)
+    : releaseS(GetNullarySelector("release", Ctx)),
+      retainS(GetNullarySelector("retain", Ctx)),
+      autoreleaseS(GetNullarySelector("autorelease", Ctx)),
+      drainS(GetNullarySelector("drain", Ctx)),
+      BT(0) {}
+
+  static void *getTag() { static int x = 0; return &x; }
+      
+  void PreVisitObjCMessageExpr(CheckerContext &C, const ObjCMessageExpr *ME);    
+};
+}
+
+void ClassReleaseChecker::PreVisitObjCMessageExpr(CheckerContext &C,
+                                                  const ObjCMessageExpr *ME) {
+  ObjCInterfaceDecl *Class = 0;
+  switch (ME->getReceiverKind()) {
+  case ObjCMessageExpr::Class:
+    Class = ME->getClassReceiver()->getAs<ObjCObjectType>()->getInterface();
+    break;
+
+  case ObjCMessageExpr::SuperClass:
+    Class = ME->getSuperType()->getAs<ObjCObjectType>()->getInterface();
+    break;
+
+  case ObjCMessageExpr::Instance:
+  case ObjCMessageExpr::SuperInstance:
+    return;
+  }
+
+  Selector S = ME->getSelector();
+  if (!(S == releaseS || S == retainS || S == autoreleaseS || S == drainS))
+    return;
+  
+  if (!BT)
+    BT = new APIMisuse("message incorrectly sent to class instead of class "
+                       "instance");
+  
+  ExplodedNode *N = C.GenerateNode();
+
+  if (!N)
+    return;
+  
+  llvm::SmallString<200> buf;
+  llvm::raw_svector_ostream os(buf);
+
+  os << "The '" << S.getAsString() << "' message should be sent to instances "
+        "of class '" << Class->getName()
+     << "' and not the class directly";
+  
+  RangedBugReport *report = new RangedBugReport(*BT, os.str(), N);
+  report->addRange(ME->getSourceRange());
+  C.EmitReport(report);
+}
+
+//===----------------------------------------------------------------------===//
+// Check registration.
+//===----------------------------------------------------------------------===//
+
+void clang::RegisterAppleChecks(GRExprEngine& Eng, const Decl &D) {
+  ASTContext& Ctx = Eng.getContext();
+  BugReporter &BR = Eng.getBugReporter();
+
+  Eng.AddCheck(CreateBasicObjCFoundationChecks(Ctx, BR),
+               Stmt::ObjCMessageExprClass);
+  Eng.AddCheck(CreateAuditCFNumberCreate(Ctx, BR), Stmt::CallExprClass);
+  Eng.AddCheck(CreateAuditCFRetainRelease(Ctx, BR), Stmt::CallExprClass);
+
+  RegisterNSErrorChecks(BR, Eng, D);
+  RegisterNSAutoreleasePoolChecks(Eng);
+  Eng.registerCheck(new ClassReleaseChecker(Ctx));
+}