[PATCH] D30593: Add correct "-isystem"/"-isysroot" warning handling to static analysis' BugReporter.

[Kevin Marshall via Phabricator via cfe-commits]

kmarshall added a comment.

Also, it looks like some instances of safe unique_ptr assignment using std::move() are tripping up the analyzer.

Error:

  ../../build/linux/debian_wheezy_amd64-sysroot/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/bits/unique_ptr.h:190:4: warning: Potential memory leak

**C++ library code:**

  template<typename _Up, typename _Ep, typename = typename
    std::enable_if
      <std::is_convertible<typename unique_ptr<_Up, _Ep>::pointer,
                           pointer>::value
       && !std::is_array<_Up>::value>::type>
    unique_ptr&
    operator=(unique_ptr<_Up, _Ep>&& __u)
    {
      reset(__u.release());
      get_deleter() = std::forward<_Ep>(__u.get_deleter());
      return *this;  // <------------------ GENERATES WARNING
    }

**Call site:**

  case Message::STRUCT: {
    MessageReader sub_reader(NULL);
    if (reader->PopStruct(&sub_reader)) {
      std::unique_ptr<base::ListValue> list_value(new base::ListValue);
      if (PopListElements(&sub_reader, list_value.get()))
        result = std::move(list_value);  // <-- GENERATES WARNING. |result| is a std::unique_ptr<base::Value>, so the std::move should be safe.
    }
    break;
  }

**Analysis trace:**

  In file included from ../../build/linux/debian_wheezy_amd64-sysroot/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/memory:85:
  ../../build/linux/debian_wheezy_amd64-sysroot/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/bits/unique_ptr.h:190:4: warning: Potential memory leak
            return *this;
            ^
  ../../dbus/values_util.cc:94:3: note: Control jumps to 'case STRUCT:'  at line 197
    switch (reader->GetDataType()) {
    ^
  ../../dbus/values_util.cc:199:11: note: Assuming the condition is true
        if (reader->PopStruct(&sub_reader)) {
            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  ../../dbus/values_util.cc:199:7: note: Taking true branch
        if (reader->PopStruct(&sub_reader)) {
        ^
  ../../dbus/values_util.cc:200:53: note: Memory is allocated
          std::unique_ptr<base::ListValue> list_value(new base::ListValue);
                                                      ^~~~~~~~~~~~~~~~~~~
  ../../dbus/values_util.cc:201:9: note: Taking true branch
          if (PopListElements(&sub_reader, list_value.get()))
          ^
  ../../dbus/values_util.cc:202:11: note: Calling 'unique_ptr::operator='
            result = std::move(list_value);
            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  ../../build/linux/debian_wheezy_amd64-sysroot/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/bits/unique_ptr.h:190:4: note: Potential memory leak
            return *this;
            ^


Repository:
  rL LLVM

https://reviews.llvm.org/D30593