[analyzer] Stability improvement for IteratorModeling

Summary:
Some function path may lead to crash.
Fixed using local variable outside the scope  through a pointer.
Fixed minor misspellings.
Added regression test.

This patch covers a bug https://bugs.llvm.org/show_bug.cgi?id=41485

Reviewed By: baloghadamsoftware

Differential Revision: https://reviews.llvm.org/D78289

diff --git a/clang/lib/StaticAnalyzer/Checkers/IteratorModeling.cpp b/clang/lib/StaticAnalyzer/Checkers/IteratorModeling.cpp
index 2850c6d..e35918e 100644 (file)
--- a/clang/lib/StaticAnalyzer/Checkers/IteratorModeling.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/IteratorModeling.cpp
@@ -402,7 +402,7 @@ void IteratorModeling::handleComparison(CheckerContext &C, const Expr *CE,
   if (!Cont)
     return;
 
-  // At least one of the iterators have recorded positions. If one of them has
+  // At least one of the iterators has recorded positions. If one of them does
   // not then create a new symbol for the offset.
   SymbolRef Sym;
   if (!LPos || !RPos) {
@@ -422,7 +422,7 @@ void IteratorModeling::handleComparison(CheckerContext &C, const Expr *CE,
     RPos = getIteratorPosition(State, RVal);
   }
 
-  // We cannot make assumpotions on `UnknownVal`. Let us conjure a symbol
+  // We cannot make assumptions on `UnknownVal`. Let us conjure a symbol
   // instead.
   if (RetVal.isUnknown()) {
     auto &SymMgr = C.getSymbolManager();
@@ -532,8 +532,9 @@ void IteratorModeling::handleRandomIncrOrDecr(CheckerContext &C,
     return;
 
   const auto *value = &RHS;
+  SVal val;
   if (auto loc = RHS.getAs<Loc>()) {
-    const auto val = State->getRawSVal(*loc);
+    val = State->getRawSVal(*loc);
     value = &val;
   }
 

diff --git a/clang/test/Analysis/iterator-range.cpp b/clang/test/Analysis/iterator-range.cpp
index bdfb04b..ad8ce92 100644 (file)
--- a/clang/test/Analysis/iterator-range.cpp
+++ b/clang/test/Analysis/iterator-range.cpp
@@ -810,6 +810,19 @@ void prev_0_end(const std::vector<int> &V) {
   auto j = std::prev(i, 0); // no-warning
 }
 
+// std::prev() with int* for checking Loc value argument
+namespace std {
+template <typename T>
+T prev(T, int *);
+}
+
+void prev_loc_value(const std::vector<int> &V, int o) {
+
+  auto i = return_any_iterator(V.begin());
+  int *offset = &o;
+  auto j = std::prev(i, offset); // no-warning
+}
+
 //
 // Structure member dereference operators
 //