[PATCH] D83190: [analyzer] Model iterator random incrementation symmetrically

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gamesh411 updated this revision to Diff 275693.
gamesh411 marked 2 inline comments as done.
gamesh411 added a comment.

rename misleading variables
apply local consts


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D83190/new/

https://reviews.llvm.org/D83190

Files:
  clang/lib/StaticAnalyzer/Checkers/IteratorModeling.cpp
  clang/test/Analysis/iterator-modeling.cpp


Index: clang/test/Analysis/iterator-modeling.cpp
===================================================================
--- clang/test/Analysis/iterator-modeling.cpp
+++ clang/test/Analysis/iterator-modeling.cpp
@@ -1948,7 +1948,7 @@
   clang_analyzer_express(clang_analyzer_iterator_position(i)); // expected-warning{{$c.end() - 2}}
 }
 
-void plus_ptr_iterator(const cont_with_ptr_iterator<int> &c) {
+void lhs_plus_ptr_iterator(const cont_with_ptr_iterator<int> &c) {
   auto i1 = c.begin();
 
   clang_analyzer_denote(clang_analyzer_container_begin(c), "$c.begin()");
@@ -1960,6 +1960,18 @@
   clang_analyzer_express(clang_analyzer_iterator_position(i2)); // expected-warning{{$c.begin() + 2}}
 }
 
+void rhs_plus_ptr_iterator(const cont_with_ptr_iterator<int> &c) {
+  auto i1 = c.begin();
+
+  clang_analyzer_denote(clang_analyzer_container_begin(c), "$c.begin()");
+
+  auto i2 = 2 + i1;
+
+  clang_analyzer_eval(clang_analyzer_iterator_container(i2) == &c); // expected-warning{{TRUE}}
+  clang_analyzer_express(clang_analyzer_iterator_position(i1));     // expected-warning{{$c.begin()}}
+  clang_analyzer_express(clang_analyzer_iterator_position(i2));     // expected-warning{{$c.begin() + 2}}
+}
+
 void minus_ptr_iterator(const cont_with_ptr_iterator<int> &c) {
   auto i1 = c.end();
 
Index: clang/lib/StaticAnalyzer/Checkers/IteratorModeling.cpp
===================================================================
--- clang/lib/StaticAnalyzer/Checkers/IteratorModeling.cpp
+++ clang/lib/StaticAnalyzer/Checkers/IteratorModeling.cpp
@@ -262,18 +262,25 @@
 
 void IteratorModeling::checkPostStmt(const BinaryOperator *BO,
                                      CheckerContext &C) const {
-  ProgramStateRef State = C.getState();
-  BinaryOperatorKind OK = BO->getOpcode();
-  SVal RVal = State->getSVal(BO->getRHS(), C.getLocationContext());
+  const ProgramStateRef State = C.getState();
+  const BinaryOperatorKind OK = BO->getOpcode();
+  const Expr *const LHS = BO->getLHS();
+  const Expr *const RHS = BO->getRHS();
+  const SVal LVal = State->getSVal(LHS, C.getLocationContext());
+  const SVal RVal = State->getSVal(RHS, C.getLocationContext());
 
   if (isSimpleComparisonOperator(BO->getOpcode())) {
-    SVal LVal = State->getSVal(BO->getLHS(), C.getLocationContext());
     SVal Result = State->getSVal(BO, C.getLocationContext());
     handleComparison(C, BO, Result, LVal, RVal,
                      BinaryOperator::getOverloadedOperator(OK));
   } else if (isRandomIncrOrDecrOperator(OK)) {
-    handlePtrIncrOrDecr(C, BO->getLHS(),
-                        BinaryOperator::getOverloadedOperator(OK), RVal);
+    // In case of operator+ the iterator can be either on the LHS (eg.: it + 1),
+    // or on the RHS (eg.: 1 + it). Both cases are modeled.
+    const bool IsIterOnLHS = BO->getLHS()->getType()->isPointerType();
+    const Expr *const &IterExpr = IsIterOnLHS ? LHS : RHS;
+    const SVal &OffsetVal = IsIterOnLHS ? RVal : LVal;
+    handlePtrIncrOrDecr(C, IterExpr, BinaryOperator::getOverloadedOperator(OK),
+                        OffsetVal);
   }
 }
 


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