예제 #1
0
/// CreateType - get objective-c interface type.
llvm::DIType CGDebugInfo::CreateType(const ObjCInterfaceType *Ty,
                                     llvm::DICompileUnit Unit) {
  ObjCInterfaceDecl *Decl = Ty->getDecl();
  
  unsigned Tag = llvm::dwarf::DW_TAG_structure_type;
  SourceManager &SM = M->getContext().getSourceManager();

  // Get overall information about the record type for the debug info.
  std::string Name = Decl->getNameAsString();

  llvm::DICompileUnit DefUnit = getOrCreateCompileUnit(Decl->getLocation());
  unsigned Line = SM.getInstantiationLineNumber(Decl->getLocation());
  
  
  // To handle recursive interface, we
  // first generate a debug descriptor for the struct as a forward declaration.
  // Then (if it is a definition) we go through and get debug info for all of
  // its members.  Finally, we create a descriptor for the complete type (which
  // may refer to the forward decl if the struct is recursive) and replace all
  // uses of the forward declaration with the final definition.
  llvm::DIType FwdDecl =
    DebugFactory.CreateCompositeType(Tag, Unit, Name, DefUnit, Line, 0, 0, 0, 0,
                                     llvm::DIType(), llvm::DIArray());
  
  // If this is just a forward declaration, return it.
  if (Decl->isForwardDecl())
    return FwdDecl;

  // Otherwise, insert it into the TypeCache so that recursive uses will find
  // it.
  TypeCache[QualType(Ty, 0).getAsOpaquePtr()] = FwdDecl;

  // Convert all the elements.
  llvm::SmallVector<llvm::DIDescriptor, 16> EltTys;

  ObjCInterfaceDecl *SClass = Decl->getSuperClass();
  if (SClass) {
    llvm::DIType SClassTy = 
      getOrCreateType(M->getContext().getObjCInterfaceType(SClass), Unit);
    llvm::DIType InhTag = 
      DebugFactory.CreateDerivedType(llvm::dwarf::DW_TAG_inheritance,
                                     Unit, "", Unit, 0, 0, 0,
                                     0 /* offset */, 0, SClassTy);
    EltTys.push_back(InhTag);
  }

  const ASTRecordLayout &RL = M->getContext().getASTObjCInterfaceLayout(Decl);

  unsigned FieldNo = 0;
  for (ObjCInterfaceDecl::ivar_iterator I = Decl->ivar_begin(),
         E = Decl->ivar_end();  I != E; ++I, ++FieldNo) {
    ObjCIvarDecl *Field = *I;
    llvm::DIType FieldTy = getOrCreateType(Field->getType(), Unit);

    std::string FieldName = Field->getNameAsString();

    // Get the location for the field.
    SourceLocation FieldDefLoc = Field->getLocation();
    llvm::DICompileUnit FieldDefUnit = getOrCreateCompileUnit(FieldDefLoc);
    unsigned FieldLine = SM.getInstantiationLineNumber(FieldDefLoc);
 
    QualType FType = Field->getType();
    uint64_t FieldSize = 0;
    unsigned FieldAlign = 0;

    if (!FType->isIncompleteArrayType()) {
    
      // Bit size, align and offset of the type.
      FieldSize = M->getContext().getTypeSize(FType);
      Expr *BitWidth = Field->getBitWidth();
      if (BitWidth)
        FieldSize = 
          BitWidth->getIntegerConstantExprValue(M->getContext()).getZExtValue();
      
      FieldAlign =  M->getContext().getTypeAlign(FType);
    }

    uint64_t FieldOffset = RL.getFieldOffset(FieldNo);    
    
    unsigned Flags = 0;
    if (Field->getAccessControl() == ObjCIvarDecl::Protected)
      Flags = llvm::DIType::FlagProtected;
    else if (Field->getAccessControl() == ObjCIvarDecl::Private)
      Flags = llvm::DIType::FlagPrivate;
      
    // Create a DW_TAG_member node to remember the offset of this field in the
    // struct.  FIXME: This is an absolutely insane way to capture this
    // information.  When we gut debug info, this should be fixed.
    FieldTy = DebugFactory.CreateDerivedType(llvm::dwarf::DW_TAG_member, Unit,
                                             FieldName, FieldDefUnit,
                                             FieldLine, FieldSize, FieldAlign,
                                             FieldOffset, Flags, FieldTy);
    EltTys.push_back(FieldTy);
  }
  
  llvm::DIArray Elements =
    DebugFactory.GetOrCreateArray(&EltTys[0], EltTys.size());

  // Bit size, align and offset of the type.
  uint64_t Size = M->getContext().getTypeSize(Ty);
  uint64_t Align = M->getContext().getTypeAlign(Ty);
  
  llvm::DIType RealDecl =
    DebugFactory.CreateCompositeType(Tag, Unit, Name, DefUnit, Line, Size,
                                     Align, 0, 0, llvm::DIType(), Elements);

  // Now that we have a real decl for the struct, replace anything using the
  // old decl with the new one.  This will recursively update the debug info.
  FwdDecl.getGV()->replaceAllUsesWith(RealDecl.getGV());
  FwdDecl.getGV()->eraseFromParent();
  
  return RealDecl;
}
예제 #2
0
void clang::CheckObjCDealloc(const ObjCImplementationDecl* D,
                             const LangOptions& LOpts, BugReporter& BR) {

  assert (LOpts.getGCMode() != LangOptions::GCOnly);

  ASTContext& Ctx = BR.getContext();
  const ObjCInterfaceDecl* ID = D->getClassInterface();

  // Does the class contain any ivars that are pointers (or id<...>)?
  // If not, skip the check entirely.
  // NOTE: This is motivated by PR 2517:
  //        http://llvm.org/bugs/show_bug.cgi?id=2517

  bool containsPointerIvar = false;

  for (ObjCInterfaceDecl::ivar_iterator I=ID->ivar_begin(), E=ID->ivar_end();
       I!=E; ++I) {

    ObjCIvarDecl* ID = *I;
    QualType T = ID->getType();

    if (!T->isObjCObjectPointerType() ||
        ID->getAttr<IBOutletAttr>()) // Skip IBOutlets.
      continue;

    containsPointerIvar = true;
    break;
  }

  if (!containsPointerIvar)
    return;

  // Determine if the class subclasses NSObject.
  IdentifierInfo* NSObjectII = &Ctx.Idents.get("NSObject");
  IdentifierInfo* SenTestCaseII = &Ctx.Idents.get("SenTestCase");


  for ( ; ID ; ID = ID->getSuperClass()) {
    IdentifierInfo *II = ID->getIdentifier();

    if (II == NSObjectII)
      break;

    // FIXME: For now, ignore classes that subclass SenTestCase, as these don't
    // need to implement -dealloc.  They implement tear down in another way,
    // which we should try and catch later.
    //  http://llvm.org/bugs/show_bug.cgi?id=3187
    if (II == SenTestCaseII)
      return;
  }

  if (!ID)
    return;

  // Get the "dealloc" selector.
  IdentifierInfo* II = &Ctx.Idents.get("dealloc");
  Selector S = Ctx.Selectors.getSelector(0, &II);
  ObjCMethodDecl* MD = 0;

  // Scan the instance methods for "dealloc".
  for (ObjCImplementationDecl::instmeth_iterator I = D->instmeth_begin(),
       E = D->instmeth_end(); I!=E; ++I) {

    if ((*I)->getSelector() == S) {
      MD = *I;
      break;
    }
  }

  if (!MD) { // No dealloc found.

    const char* name = LOpts.getGCMode() == LangOptions::NonGC
                       ? "missing -dealloc"
                       : "missing -dealloc (Hybrid MM, non-GC)";

    std::string buf;
    llvm::raw_string_ostream os(buf);
    os << "Objective-C class '" << D->getNameAsString()
       << "' lacks a 'dealloc' instance method";

    BR.EmitBasicReport(name, os.str().c_str(), D->getLocStart());
    return;
  }

  // dealloc found.  Scan for missing [super dealloc].
  if (MD->getBody() && !scan_dealloc(MD->getBody(), S)) {

    const char* name = LOpts.getGCMode() == LangOptions::NonGC
                       ? "missing [super dealloc]"
                       : "missing [super dealloc] (Hybrid MM, non-GC)";

    std::string buf;
    llvm::raw_string_ostream os(buf);
    os << "The 'dealloc' instance method in Objective-C class '"
       << D->getNameAsString()
       << "' does not send a 'dealloc' message to its super class"
           " (missing [super dealloc])";

    BR.EmitBasicReport(name, os.str().c_str(), D->getLocStart());
    return;
  }

  // Get the "release" selector.
  IdentifierInfo* RII = &Ctx.Idents.get("release");
  Selector RS = Ctx.Selectors.getSelector(0, &RII);

  // Get the "self" identifier
  IdentifierInfo* SelfII = &Ctx.Idents.get("self");

  // Scan for missing and extra releases of ivars used by implementations
  // of synthesized properties
  for (ObjCImplementationDecl::propimpl_iterator I = D->propimpl_begin(),
       E = D->propimpl_end(); I!=E; ++I) {

    // We can only check the synthesized properties
    if ((*I)->getPropertyImplementation() != ObjCPropertyImplDecl::Synthesize)
      continue;

    ObjCIvarDecl* ID = (*I)->getPropertyIvarDecl();
    if (!ID)
      continue;

    QualType T = ID->getType();
    if (!T->isObjCObjectPointerType()) // Skip non-pointer ivars
      continue;

    const ObjCPropertyDecl* PD = (*I)->getPropertyDecl();
    if (!PD)
      continue;

    // ivars cannot be set via read-only properties, so we'll skip them
    if (PD->isReadOnly())
       continue;

    // ivar must be released if and only if the kind of setter was not 'assign'
    bool requiresRelease = PD->getSetterKind() != ObjCPropertyDecl::Assign;
    if (scan_ivar_release(MD->getBody(), ID, PD, RS, SelfII, Ctx)
       != requiresRelease) {
      const char *name;
      const char* category = "Memory (Core Foundation/Objective-C)";

      std::string buf;
      llvm::raw_string_ostream os(buf);

      if (requiresRelease) {
        name = LOpts.getGCMode() == LangOptions::NonGC
               ? "missing ivar release (leak)"
               : "missing ivar release (Hybrid MM, non-GC)";

        os << "The '" << ID->getNameAsString()
           << "' instance variable was retained by a synthesized property but "
              "wasn't released in 'dealloc'";
      } else {
        name = LOpts.getGCMode() == LangOptions::NonGC
               ? "extra ivar release (use-after-release)"
               : "extra ivar release (Hybrid MM, non-GC)";

        os << "The '" << ID->getNameAsString()
           << "' instance variable was not retained by a synthesized property "
              "but was released in 'dealloc'";
      }

      BR.EmitBasicReport(name, category,
                         os.str().c_str(), (*I)->getLocation());
    }
  }
}