[LLVMbugs] [Bug 18394] New: alpha.cplusplus.NewDeleteLeaks false-positive complicated conditions

[bugzilla-daemon at llvm.org]

http://llvm.org/bugs/show_bug.cgi?id=18394

            Bug ID: 18394
           Summary: alpha.cplusplus.NewDeleteLeaks false-positive
                    complicated conditions
           Product: clang
           Version: trunk
          Hardware: PC
                OS: Windows NT
            Status: NEW
          Severity: normal
          Priority: P
         Component: Static Analyzer
          Assignee: kremenek at apple.com
          Reporter: anton.yartsev at Gmail.com
                CC: llvmbugs at cs.uiuc.edu
    Classification: Unclassified

Here is a minimal test that illustrates the problem. My attempts to simplify
the test led to the fact that the leak is not reported. The leak also
disappears if '-std=c++11' option is given to the compiler.

class Iter {
  public:
   int * _M_current;

   Iter(int * __i) : _M_current(__i) { }
   int * base() { return _M_current; }
};

bool operator==(Iter __lhs, Iter __rhs)
{ return __lhs.base() == __rhs.base(); }

class vector  {
public:

  int* _M_start;
  int* _M_finish;

  public:
    Iter begin() const
    { return Iter(_M_start); }

    Iter end() const
    { return Iter(_M_finish); }

    bool empty() { return begin() == end(); }
};

class raw_ostream {
public:
  char *OutBufEnd, *OutBufCur;

  int m() {
    if (OutBufCur >= OutBufEnd)
      return 1;

    return 0;
  }
};

raw_ostream *v;
vector *interestingSymbols;

class A {
public:
  bool f();
  ~A() {
    while (f()) {
      interestingSymbols->empty();
      interestingSymbols->empty();
      interestingSymbols->empty();
    }
  }
};

void error() {
  A *a = new A();
  delete a; // false-positive leak!

  v->m();
  v->m();
  v->m();
}

F:\llvm_COMMON\-VS_build-\Debug\bin>clang -cc1
-analyzer-checker=alpha.cplusplus.NewDeleteLeaks -analyze test.cpp 
test.cpp:59:3: warning: Potential leak of memory pointed to by 'a'
  delete a; // false-positive leak!
  ^~~~~~~~
1 warning generated.

-- 
You are receiving this mail because:
You are on the CC list for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-bugs/attachments/20140106/29e73ead/attachment.html>