C语言中调用main函数的堆栈信息

#define _SCRT_STARTUP_MAIN
#include "exe_common.inl"



extern "C" int mainCRTStartup()
{
    return __scrt_common_main();
}

在exe_common.inl文件中,可以看到__scrt_common_main函数. 可以先看看不同程序(控制台/窗口程序),调用的函数是不一样的.

//
// exe_common.inl
//
//      Copyright (c) Microsoft Corporation. All rights reserved.
//
// The implementation of the common executable entry point code.  There are four
// executable entry points defined by the CRT, one for each of the user-definable
// entry points:
//
//  * mainCRTStartup     => main
//  * wmainCRTStartup    => wmain
//  * WinMainCRTStartup  => WinMain
//  * wWinMainCRTStartup => wWinMain
//
// These functions all behave the same, except for which user-definable main
// function they call and whether they accumulate and pass narrow or wide string
// arguments.  This file contains the common code shared by all four of those
// entry points.
//
// The actual entry points are defined in four .cpp files alongside this .inl
// file.  At most one of these .cpp files will be linked into the resulting
// executable, so we can treat this .inl file as if its contents are only linked
// into the executable once as well.

static __declspec(noinline) int __cdecl __scrt_common_main_seh()
{
    if (!__scrt_initialize_crt(__scrt_module_type::exe))
        __scrt_fastfail(FAST_FAIL_FATAL_APP_EXIT);

    bool has_cctor = false;
    __try
    {
        bool const is_nested = __scrt_acquire_startup_lock();

        if (__scrt_current_native_startup_state == __scrt_native_startup_state::initializing)
        {
            __scrt_fastfail(FAST_FAIL_FATAL_APP_EXIT);
        }
        else if (__scrt_current_native_startup_state == __scrt_native_startup_state::uninitialized)
        {
            __scrt_current_native_startup_state = __scrt_native_startup_state::initializing;

            if (_initterm_e(__xi_a, __xi_z) != 0)
                return 255;

            _initterm(__xc_a, __xc_z);

            __scrt_current_native_startup_state = __scrt_native_startup_state::initialized;
        }
        else
        {
            has_cctor = true;
        }

        __scrt_release_startup_lock(is_nested);

        // If this module has any dynamically initialized __declspec(thread)
        // variables, then we invoke their initialization for the primary thread
        // used to start the process:
        _tls_callback_type const* const tls_init_callback = __scrt_get_dyn_tls_init_callback();
        if (*tls_init_callback != nullptr && __scrt_is_nonwritable_in_current_image(tls_init_callback))
        {
            (*tls_init_callback)(nullptr, DLL_THREAD_ATTACH, nullptr);
        }

        // If this module has any thread-local destructors, register the
        // callback function with the Unified CRT to run on exit.
        _tls_callback_type const * const tls_dtor_callback = __scrt_get_dyn_tls_dtor_callback();
        if (*tls_dtor_callback != nullptr && __scrt_is_nonwritable_in_current_image(tls_dtor_callback))
        {
            _register_thread_local_exe_atexit_callback(*tls_dtor_callback);
        }

        //
        // Initialization is complete; invoke main...
        //

        int const main_result = invoke_main();

        //
        // main has returned; exit somehow...
        //

        if (!__scrt_is_managed_app())
            exit(main_result);

        if (!has_cctor)
            _cexit();

        // Finally, we terminate the CRT:
        __scrt_uninitialize_crt(true, false);
        return main_result;
    }
    __except (_seh_filter_exe(GetExceptionCode(), GetExceptionInformation()))
    {
        // Note:  We should never reach this except clause.
        int const main_result = GetExceptionCode();

        if (!__scrt_is_managed_app())
            _exit(main_result);

        if (!has_cctor)
            _c_exit();

        return main_result;
    }
}



// This is the common main implementation to which all of the CRT main functions
// delegate (for executables; DLLs are handled separately).
static __forceinline int __cdecl __scrt_common_main()
{
    // The /GS security cookie must be initialized before any exception handling
    // targeting the current image is registered.  No function using exception
    // handling can be called in the current image until after this call:
    __security_init_cookie();

    return __scrt_common_main_seh();
}

在vs2019的VCRuntime下,找到源码看到上面的调用关系,基本上看不到堆初始化代码了,在官方文档上看到,在vs2015的时候,重构CRT(C Runtime),不过上面的代码也能了解调用的关系了.