r341792 - [Analyzer] Iterator Checker - Part 6: Mismatched iterator checker for constructors and comparisons

[Adam Balogh via cfe-commits]

Author: baloghadamsoftware
Date: Mon Sep 10 02:05:31 2018
New Revision: 341792

URL: http://llvm.org/viewvc/llvm-project?rev=341792&view=rev
Log:
[Analyzer] Iterator Checker - Part 6: Mismatched iterator checker for constructors and comparisons

Extension of the mismatched iterator checker for constructors taking range of first..last (first and last must be iterators of the same container) and also for comparisons of iterators of different containers (one does not compare iterators of different containers, since the set of iterators is partially ordered, there are no relations between iterators of different containers, except that they are always non-equal).

Differential Revision: https://reviews.llvm.org/D32860


Modified:
    cfe/trunk/lib/StaticAnalyzer/Checkers/IteratorChecker.cpp

Modified: cfe/trunk/lib/StaticAnalyzer/Checkers/IteratorChecker.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/StaticAnalyzer/Checkers/IteratorChecker.cpp?rev=341792&r1=341791&r2=341792&view=diff
==============================================================================
--- cfe/trunk/lib/StaticAnalyzer/Checkers/IteratorChecker.cpp (original)
+++ cfe/trunk/lib/StaticAnalyzer/Checkers/IteratorChecker.cpp Mon Sep 10 02:05:31 2018
@@ -236,6 +236,9 @@ class IteratorChecker
   void reportMismatchedBug(const StringRef &Message, const SVal &Val1,
                            const SVal &Val2, CheckerContext &C,
                            ExplodedNode *ErrNode) const;
+  void reportMismatchedBug(const StringRef &Message, const SVal &Val,
+                           const MemRegion *Reg, CheckerContext &C,
+                           ExplodedNode *ErrNode) const;
   void reportInvalidatedBug(const StringRef &Message, const SVal &Val,
                             CheckerContext &C, ExplodedNode *ErrNode) const;
 
@@ -276,6 +279,7 @@ namespace {
 
 bool isIteratorType(const QualType &Type);
 bool isIterator(const CXXRecordDecl *CRD);
+bool isComparisonOperator(OverloadedOperatorKind OK);
 bool isBeginCall(const FunctionDecl *Func);
 bool isEndCall(const FunctionDecl *Func);
 bool isAssignmentOperator(OverloadedOperatorKind OK);
@@ -397,8 +401,48 @@ void IteratorChecker::checkPreCall(const
       } else {
         verifyDereference(C, Call.getArgSVal(0));
       }
+    } else if (ChecksEnabled[CK_MismatchedIteratorChecker] &&
+               isComparisonOperator(Func->getOverloadedOperator())) {
+      // Check for comparisons of iterators of different containers
+      if (const auto *InstCall = dyn_cast<CXXInstanceCall>(&Call)) {
+        if (Call.getNumArgs() < 1)
+          return;
+
+        if (!isIteratorType(InstCall->getCXXThisExpr()->getType()) ||
+            !isIteratorType(Call.getArgExpr(0)->getType()))
+          return;
+
+        verifyMatch(C, InstCall->getCXXThisVal(), Call.getArgSVal(0));
+      } else {
+        if (Call.getNumArgs() < 2)
+          return;
+
+        if (!isIteratorType(Call.getArgExpr(0)->getType()) ||
+            !isIteratorType(Call.getArgExpr(1)->getType()))
+          return;
+
+        verifyMatch(C, Call.getArgSVal(0), Call.getArgSVal(1));
+      }
     }
-  } else if (!isa<CXXConstructorCall>(&Call)) {
+  } else if (isa<CXXConstructorCall>(&Call)) {
+    // Check match of first-last iterator pair in a constructor of a container
+    if (Call.getNumArgs() < 2)
+      return;
+
+    const auto *Ctr = cast<CXXConstructorDecl>(Call.getDecl());
+    if (Ctr->getNumParams() < 2)
+      return;
+
+    if (Ctr->getParamDecl(0)->getName() != "first" ||
+        Ctr->getParamDecl(1)->getName() != "last")
+      return;
+
+    if (!isIteratorType(Call.getArgExpr(0)->getType()) ||
+        !isIteratorType(Call.getArgExpr(1)->getType()))
+      return;
+
+    verifyMatch(C, Call.getArgSVal(0), Call.getArgSVal(1));
+  } else {
     // The main purpose of iterators is to abstract away from different
     // containers and provide a (maybe limited) uniform access to them.
     // This implies that any correctly written template function that
@@ -1102,6 +1146,16 @@ void IteratorChecker::reportMismatchedBu
   C.emitReport(std::move(R));
 }
 
+void IteratorChecker::reportMismatchedBug(const StringRef &Message,
+                                          const SVal &Val, const MemRegion *Reg,
+                                          CheckerContext &C,
+                                          ExplodedNode *ErrNode) const {
+  auto R = llvm::make_unique<BugReport>(*MismatchedBugType, Message, ErrNode);
+  R->markInteresting(Val);
+  R->markInteresting(Reg);
+  C.emitReport(std::move(R));
+}
+
 void IteratorChecker::reportInvalidatedBug(const StringRef &Message,
                                            const SVal &Val, CheckerContext &C,
                                            ExplodedNode *ErrNode) const {
@@ -1173,6 +1227,11 @@ bool isIterator(const CXXRecordDecl *CRD
          HasPostIncrOp && HasDerefOp;
 }
 
+bool isComparisonOperator(OverloadedOperatorKind OK) {
+  return OK == OO_EqualEqual || OK == OO_ExclaimEqual || OK == OO_Less ||
+         OK == OO_LessEqual || OK == OO_Greater || OK == OO_GreaterEqual;
+}
+
 bool isBeginCall(const FunctionDecl *Func) {
   const auto *IdInfo = Func->getIdentifier();
   if (!IdInfo)