使用 uftrace 分析C++程序后如何理解 2 个 main(） 函数

我正在尝试uftrace来分析以下简单的C++程序：

#include <iostream>
class A {
public:
        A() {std::cout << "A is created" << std::endl;}
        ~A() {std::cout << "A is destroyed" << std::endl;}
};
int main() {
        A a;
        return 0;
}

配置文件结果如下所示：

# uftrace a.out
A is created
A is destroyed
# DURATION    TID     FUNCTION
   2.026 us [ 4828] | __cxa_atexit();
            [ 4828] | main() {
            [ 4828] |   __static_initialization_and_destruction_0() {
  89.397 us [ 4828] |     std::ios_base::Init::Init();
   0.768 us [ 4828] |     __cxa_atexit();
  93.029 us [ 4828] |   } /* __static_initialization_and_destruction_0 */
  94.425 us [ 4828] | } /* main */
            [ 4828] | main() {
            [ 4828] |   A::A() {
  11.104 us [ 4828] |     std::operator <<();
  10.825 us [ 4828] |     std::basic_ostream::operator <<();
  24.514 us [ 4828] |   } /* A::A */
            [ 4828] |   A::~A() {
   0.978 us [ 4828] |     std::operator <<();
   1.676 us [ 4828] |     std::basic_ostream::operator <<();
   4.819 us [ 4828] |   } /* A::~A */
  31.428 us [ 4828] | } /* main */
   2.095 us [ 4828] | std::ios_base::Init::~Init();

让我感到困惑的是有2 main()功能。从跟踪中，我想它们与iostream初始化有关，但即使如此，我认为每个可执行文件应该只有1 main()条目。如何解读？