[analyzer] Add an experimental ObjC direct ivar assignment checker.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@164790 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/StaticAnalyzer/Checkers/DirectIvarAssignment.cpp b/lib/StaticAnalyzer/Checkers/DirectIvarAssignment.cpp
new file mode 100644
index 0000000..db3a885
--- /dev/null
+++ b/lib/StaticAnalyzer/Checkers/DirectIvarAssignment.cpp
@@ -0,0 +1,178 @@
+//=- DirectIvarAssignment.cpp - Check rules on ObjC properties -*- C++ ----*-==//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Check that Objective C properties follow the following rules:
+// - The property should be set with the setter, not though a direct
+// assignment.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ClangSACheckers.h"
+#include "clang/StaticAnalyzer/Core/Checker.h"
+#include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h"
+#include "clang/AST/DeclObjC.h"
+#include "clang/AST/StmtVisitor.h"
+#include "llvm/ADT/DenseMap.h"
+
+using namespace clang;
+using namespace ento;
+
+namespace {
+
+class DirectIvarAssignment :
+ public Checker<check::ASTDecl<ObjCImplementationDecl> > {
+
+ typedef llvm::DenseMap<const ObjCIvarDecl*,
+ const ObjCPropertyDecl*> IvarToPropertyMapTy;
+
+ /// A helper class, which walks the AST and locates all assignments to ivars
+ /// in the given function.
+ class MethodCrawler : public ConstStmtVisitor<MethodCrawler> {
+ const IvarToPropertyMapTy &IvarToPropMap;
+ const ObjCMethodDecl *MD;
+ const ObjCInterfaceDecl *InterfD;
+ BugReporter &BR;
+ LocationOrAnalysisDeclContext DCtx;
+
+ public:
+ MethodCrawler(const IvarToPropertyMapTy &InMap, const ObjCMethodDecl *InMD,
+ const ObjCInterfaceDecl *InID,
+ BugReporter &InBR, AnalysisDeclContext *InDCtx)
+ : IvarToPropMap(InMap), MD(InMD), InterfD(InID), BR(InBR), DCtx(InDCtx) {}
+
+ void VisitStmt(const Stmt *S) { VisitChildren(S); }
+
+ void VisitBinaryOperator(const BinaryOperator *BO);
+
+ void VisitChildren(const Stmt *S) {
+ for (Stmt::const_child_range I = S->children(); I; ++I)
+ if (*I)
+ this->Visit(*I);
+ }
+ };
+
+public:
+ void checkASTDecl(const ObjCImplementationDecl *D, AnalysisManager& Mgr,
+ BugReporter &BR) const;
+};
+
+static const ObjCIvarDecl *findPropertyBackingIvar(const ObjCPropertyDecl *PD,
+ ObjCInterfaceDecl *InterD,
+ ASTContext &Ctx) {
+ // Check for synthesized ivars.
+ ObjCIvarDecl *ID = PD->getPropertyIvarDecl();
+ if (ID)
+ return ID;
+
+ // Check for existing "_PropName".
+ ID = InterD->lookupInstanceVariable(PD->getDefaultSynthIvarName(Ctx));
+ if (ID)
+ return ID;
+
+ // Check for existing "PropName".
+ IdentifierInfo *PropIdent = PD->getIdentifier();
+ ID = InterD->lookupInstanceVariable(PropIdent);
+
+ return ID;
+}
+
+void DirectIvarAssignment::checkASTDecl(const ObjCImplementationDecl *D,
+ AnalysisManager& Mgr,
+ BugReporter &BR) const {
+ const ObjCInterfaceDecl *InterD = D->getClassInterface();
+
+
+ IvarToPropertyMapTy IvarToPropMap;
+
+ // Find all properties for this class.
+ for (ObjCInterfaceDecl::prop_iterator I = InterD->prop_begin(),
+ E = InterD->prop_end(); I != E; ++I) {
+ ObjCPropertyDecl *PD = *I;
+
+ // Find the corresponding IVar.
+ const ObjCIvarDecl *ID = findPropertyBackingIvar(PD,
+ const_cast<ObjCInterfaceDecl*>(InterD),
+ Mgr.getASTContext());
+
+ if (!ID)
+ continue;
+
+ // Store the IVar to property mapping.
+ IvarToPropMap[ID] = PD;
+ }
+
+ if (IvarToPropMap.empty())
+ return;
+
+ for (ObjCImplementationDecl::instmeth_iterator I = D->instmeth_begin(),
+ E = D->instmeth_end(); I != E; ++I) {
+
+ ObjCMethodDecl *M = *I;
+ AnalysisDeclContext *DCtx = Mgr.getAnalysisDeclContext(M);
+
+ if (M->getMethodFamily() == OMF_init ||
+ M->getMethodFamily() == OMF_dealloc ||
+ M->getSelector().getAsString().find("init") != StringRef::npos ||
+ M->getSelector().getAsString().find("Init") != StringRef::npos)
+ continue;
+
+ const Stmt *Body = M->getBody();
+ if (!Body)
+ continue;
+
+ MethodCrawler MC(IvarToPropMap, M->getCanonicalDecl(), InterD, BR, DCtx);
+ MC.VisitStmt(Body);
+ }
+}
+
+void DirectIvarAssignment::MethodCrawler::VisitBinaryOperator(
+ const BinaryOperator *BO) {
+ if (!BO->isAssignmentOp())
+ return;
+
+ const ObjCIvarRefExpr *IvarRef = dyn_cast<ObjCIvarRefExpr>(BO->getLHS());
+
+ if (!IvarRef)
+ return;
+
+ if (const ObjCIvarDecl *D = IvarRef->getDecl()) {
+ IvarToPropertyMapTy::const_iterator I = IvarToPropMap.find(D);
+ if (I != IvarToPropMap.end()) {
+ const ObjCPropertyDecl *PD = I->second;
+
+ ObjCMethodDecl *GetterMethod =
+ InterfD->getInstanceMethod(PD->getGetterName());
+ ObjCMethodDecl *SetterMethod =
+ InterfD->getInstanceMethod(PD->getSetterName());
+
+ if (SetterMethod && SetterMethod->getCanonicalDecl() == MD)
+ return;
+
+ if (GetterMethod && GetterMethod->getCanonicalDecl() == MD)
+ return;
+
+
+ PathDiagnosticLocation IvarRefLocation =
+ PathDiagnosticLocation::createBegin(IvarRef,
+ BR.getSourceManager(), DCtx);
+
+ BR.EmitBasicReport(MD,
+ "Property access",
+ categories::CoreFoundationObjectiveC,
+ "Direct assignment to an instance variable backing a property; "
+ "use the setter instead", IvarRefLocation);
+ }
+ }
+}
+}
+
+void ento::registerDirectIvarAssignment(CheckerManager &mgr) {
+ mgr.registerChecker<DirectIvarAssignment>();
+}