[VCSTARTUP] Implement (w)mainCRTStartup

__acrt_initialize is here as a stub to later support linking ucrt statically. When it is statically linked the real function should be called, but when the executable links to ucrtdll, the initialization happens when the DLL is loaded, so we call a stub here.

sdk/lib/vcruntime/CMakeLists.txt

@@ -31,7 +31,10 @@ list(APPEND VCRT_RUNTIME_SOURCES
 )
 
 list(APPEND VCRT_STARTUP_SOURCES
+    __acrt_initialize_stub.cpp
     __scrt_uninitialize_crt.cpp
+    mainCRTStartup.cpp
+    wmainCRTStartup.cpp
 )
 
 if(${ARCH} STREQUAL "i386")

sdk/lib/vcruntime/__acrt_initialize_stub.cpp

@@ -0,0 +1,8 @@
+
+#include <internal_shared.h>
+
+extern "C"
+__crt_bool __cdecl __acrt_initialize()
+{
+    return true;
+}

sdk/lib/vcruntime/commonCRTStartup.hpp

@@ -0,0 +1,89 @@
+//
+// commonCRTStartup.c
+//
+//      Copyright (c) 2024 Timo Kreuzer
+//
+// Implementation of common executable startup code.
+//
+// SPDX-License-Identifier: MIT
+//
+
+#include <corecrt_startup.h>
+#include <internal_shared.h>
+#include <excpt.h>
+#include <stdlib.h>
+#include <intrin.h>
+#include <pseh/pseh2.h>
+
+// Defined in winnt.h
+#define FAST_FAIL_FATAL_APP_EXIT 7
+
+extern "C" int __cdecl main(int, char**, char**);
+extern "C" int __cdecl wmain(int, wchar_t**, wchar_t**);
+
+template<typename Tmain>
+static int call_main();
+
+template<>
+int call_main<decltype(main)>()
+{
+    _configure_narrow_argv(_crt_argv_unexpanded_arguments);
+
+    return main(*__p___argc(), *__p___argv(), _get_initial_narrow_environment());
+}
+
+template<>
+int call_main<decltype(wmain)>()
+{
+    _configure_wide_argv(_crt_argv_unexpanded_arguments);
+
+    return wmain(*__p___argc(), *__p___wargv(), _get_initial_wide_environment());
+}
+
+static bool __scrt_initialize()
+{
+    __isa_available_init();
+
+    if (!__vcrt_initialize())
+    {
+        return false;
+    }
+
+    if (!__acrt_initialize())
+    {
+        __vcrt_uninitialize(false);
+        return false;
+    }
+
+    if (_initterm_e(__xi_a, __xi_z) != 0)
+    {
+        return false;
+    }
+
+    _initterm(__xc_a, __xc_z);
+
+    return true;
+}
+
+template<typename Tmain>
+static __declspec(noinline) int __cdecl __commonCRTStartup()
+{
+    int exitCode;
+
+    if (!__scrt_initialize())
+    {
+        __fastfail(FAST_FAIL_FATAL_APP_EXIT);
+    }
+
+    __try
+    {
+        exitCode = call_main<Tmain>();
+    }
+    __except(EXCEPTION_EXECUTE_HANDLER)
+    {
+        exitCode = GetExceptionCode();
+    }
+    __endtry
+
+    exit(exitCode);
+}

sdk/lib/vcruntime/mainCRTStartup.cpp

@@ -0,0 +1,18 @@
+//
+// mainCRTStartup.c
+//
+//      Copyright (c) 2024 Timo Kreuzer
+//
+// Implementation of ANSI executable entry point.
+//
+// SPDX-License-Identifier: MIT
+//
+
+#include "commonCRTStartup.hpp"
+
+extern "C" unsigned long mainCRTStartup(void*)
+{
+    __security_init_cookie();
+
+    return __commonCRTStartup<decltype(main)>();
+}

sdk/lib/vcruntime/wmainCRTStartup.cpp

@@ -0,0 +1,18 @@
+//
+// wmainCRTStartup.c
+//
+//      Copyright (c) 2024 Timo Kreuzer
+//
+// Implementation of unicode executable entry point.
+//
+// SPDX-License-Identifier: MIT
+//
+
+#include "commonCRTStartup.hpp"
+
+extern "C" unsigned long wmainCRTStartup(void*)
+{
+    __security_init_cookie();
+
+    return __commonCRTStartup<decltype(wmain)>();
+}