C / C++ / MFC

jschell wrote:

C, so before C++, would limit the scope to the method.

jschell wrote:

So if one has 3 for loops in one method with each in a block for a if statement, the compiler might or might not have limited it to the block.

Randor wrote:

Could you point out what you are referring to?

Randor wrote:

6.2.4 Storage durations of objects

4 An object whose identifier is declared with no linkage and without the storage-class specifier statich asautomatic storage duration. 

5 For such an object that does not have a variable length array type, its lifetime extends from entry into the block with which it is associated until execution of that block ends in anyway.(Entering an enclosed block or calling a function suspends, but does not end, execution of the current block.) If the block is entered recursively, a new instance of the object is created each time. The initial value of the object is indeterminate. If an initialization is specified for the object, it is performed each time the declaration is reached in the execution of the block; otherwise, the value becomes indeterminate each time the declaration is reached.

Calin Negru wrote:

the program will allocate memory for an int every frame.

Dave Kreskowiak wrote:

It is possible to allocate a value type on the heap, generally called "boxing".

BOOL IsRunAsAdministrator()
{
    BOOL isRunAsAdmin = FALSE;
    DWORD dwError = ERROR_SUCCESS;
    PSID pAdministratorsGroup = NULL;

    // Allocate and initialize a SID of the administrators group.
    SID_IDENTIFIER_AUTHORITY NtAuthority = SECURITY_NT_AUTHORITY;
    if (!AllocateAndInitializeSid(
        &NtAuthority, 
        2, 
        SECURITY_BUILTIN_DOMAIN_RID, 
        DOMAIN_ALIAS_RID_ADMINS, 
        0, 0, 0, 0, 0, 0, 
        &pAdministratorsGroup))
    {
        goto Cleanup;
    }

    // Determine whether the SID of administrators group is enabled in 
    // the primary access token of the process.
    if (!CheckTokenMembership(NULL, pAdministratorsGroup, &isRunAsAdmin))
    {
        goto Cleanup;
    }

Cleanup:
    // Centralized cleanup for all allocated resources.
    if (pAdministratorsGroup)
    {
        FreeSid(pAdministratorsGroup);
        pAdministratorsGroup = NULL;
    }

    return isRunAsAdmin;
}

void RunServiceAsAdmin(char ch, const char *program, const char* name)
{
	// Launch itself as admin
	char param[255];
	SHELLEXECUTEINFO sei = { sizeof(sei) };

	memset(param, 0 , sizeof(param));
	sei.lpVerb = "runas";
	sei.lpFile = "sc.exe";
	sei.hwnd = NULL;
	sei.nShow = SW_NORMAL;

	if(ch == 'I')
	{
		sprintf(param, "create \"%s\" binPath= \"%s\" DisplayName=\"%s\"", name, program, name);
	}
	else
	{
		sprintf(param, "delete \"%s\"", name);
	}

	sei.lpParameters = param;

	if (!ShellExecuteEx(&sei))
	{
		show_error();
	}
}

BOOL IsRunAsAdministrator()
{
    BOOL isRunAsAdmin = FALSE;
    DWORD dwError = ERROR_SUCCESS;
    PSID pAdministratorsGroup = NULL;

    // Allocate and initialize a SID of the administrators group.
    SID_IDENTIFIER_AUTHORITY NtAuthority = SECURITY_NT_AUTHORITY;
    if (!AllocateAndInitializeSid(
        &NtAuthority, 
        2, 
        SECURITY_BUILTIN_DOMAIN_RID, 
        DOMAIN_ALIAS_RID_ADMINS, 
        0, 0, 0, 0, 0, 0, 
        &pAdministratorsGroup))
    {
        goto Cleanup;
    }

    // Determine whether the SID of administrators group is enabled in 
    // the primary access token of the process.
    if (!CheckTokenMembership(NULL, pAdministratorsGroup, &isRunAsAdmin))
    {
        goto Cleanup;
    }

Cleanup:
    // Centralized cleanup for all allocated resources.
    if (pAdministratorsGroup)
    {
        FreeSid(pAdministratorsGroup);
        pAdministratorsGroup = NULL;
    }

    return isRunAsAdmin;
}

void RunServiceAsAdmin(char ch, const char *program, const char* name)
{
	// Launch itself as admin
	char param[255];
	SHELLEXECUTEINFO sei = { sizeof(sei) };

	memset(param, 0 , sizeof(param));
	sei.lpVerb = "runas";
	sei.lpFile = "sc.exe";
	sei.hwnd = NULL;
	sei.nShow = SW_NORMAL;

	if(ch == 'I')
	{
		sprintf(param, "create \"%s\" binPath= \"%s\" DisplayName=\"%s\"", name, program, name);
	}
	else
	{
		sprintf(param, "delete \"%s\"", name);
	}

	sei.lpParameters = param;

	if (!ShellExecuteEx(&sei))
	{
		show_error();
	}
}

static int manage_service(int action) {
	SC_HANDLE hSCM = NULL, hService = NULL;
	SERVICE_DESCRIPTION descr = { server_name };
	char path[PATH_MAX + 20]; // Path to executable plus magic argument
	int success = 1;

	GetModuleFileName(NULL, path, sizeof(path));
	strncat(path, " ", sizeof(path));
	strncat(path, service_magic_argument, sizeof(path));

	if (IsRunAsAdministrator()) {
		if ((hSCM = OpenSCManager(NULL, NULL, action == ID_INSTALL_SERVICE ?
			GENERIC_WRITE : GENERIC_READ)) == NULL) {
			success = 0;
			show_error();
		}
		else if (action == ID_INSTALL_SERVICE) {
			hService = CreateService(hSCM, service_name, service_name,
				SERVICE_ALL_ACCESS, SERVICE_WIN32_OWN_PROCESS,
				SERVICE_AUTO_START, SERVICE_ERROR_NORMAL,
				path, NULL, NULL, NULL, NULL, NULL);
			if (hService) {
				ChangeServiceConfig(hService, SERVICE_NO_CHANGE, SERVICE_AUTO_START,
					SERVICE_NO_CHANGE, NULL, NULL, NULL, NULL, NULL, NULL, NULL);
				ChangeServiceConfig2(hService, SERVICE_CONFIG_DESCRIPTION, &descr);

				// Check Windows version
				OSVERSIONINFOEX osvi;
				ZeroMemory(&osvi, sizeof(OSVERSIONINFOEX));
				osvi.dwOSVersionInfoSize = sizeof(OSVERSIONINFOEX);
				osvi.dwMajorVersion = 11; // Windows 11

				if (GetVersionEx((OSVERSIONINFO*)&osvi)) {
					// Set start type to AUTO_START for Windows 11
					ChangeServiceConfig(hService, SERVICE_NO_CHANGE, SERVICE_AUTO_START,
						SERVICE_NO_CHANGE, NULL, NULL, NULL, NULL, NULL, NULL, NULL);
				}
			}
			else {
				show_error();
			}
		}
		else if (action == ID_REMOVE_SERVICE) {
			if ((hService = OpenService(hSCM, service_name, DELETE)) == NULL ||
				!DeleteService(hService)) {
				show_error();
			}
		}
		else if ((hService = OpenService(hSCM, service_name,
			SERVICE_QUERY_STATUS)) == NULL) {
			success = 0;
		}

		CloseServiceHandle(hService);
		CloseServiceHandle(hSCM);
	}
	else {
		if (action == ID_INSTALL_SERVICE) {
			RunServiceAsAdmin('I', path, service_name);
		}
		else if (action == ID_REMOVE_SERVICE) {
			RunServiceAsAdmin('R', path, service_name);
		}
		else {
			if ((hSCM = OpenSCManager(NULL, NULL, GENERIC_READ)) == NULL) {
				success = 0;
				show_error();
			}
			if ((hService = OpenService(hSCM, service_name,
				SERVICE_QUERY_STATUS)) == NULL) {
				success = 0;
			}

			CloseServiceHandle(hService);
			CloseServiceHandle(hSCM);
		}
	}

	return success;
}

static LONG queryServiceStatus(const char* serviceName){
	SC_HANDLE hSCM = NULL, hService = NULL;
	SERVICE_STATUS_PROCESS ssStatus; 
	DWORD dwBytesNeeded;
	LONG status = 0;
	if ((hSCM = OpenSCManager(NULL, NULL, GENERIC_READ)) == NULL) {
		show_error();
		return 0;
	} 
			
	// Get a handle to the service.
    hService = OpenService( 
        hSCM,         // SCM database 
        serviceName,            // name of service 
        SERVICE_QUERY_STATUS);  // full access 
 
    if (hService == NULL)
    {
        goto END_QUERY;
    }    

    // Check the status in case the service is not stopped. 
    if (!QueryServiceStatusEx( 
            hService,                     // handle to service 
            SC_STATUS_PROCESS_INFO,         // information level
            (LPBYTE) &ssStatus,             // address of structure
            sizeof(SERVICE_STATUS_PROCESS), // size of structure
            &dwBytesNeeded ) )              // size needed if buffer is too small
    {
        goto END_QUERY;
    }

    // Check if the service is already running. It would be possible 
    // to stop the service here, but for simplicity this example just returns. 

    if(ssStatus.dwCurrentState == SERVICE_RUNNING)
    {
       status = SERVICE_RUNNING;
	   goto END_QUERY;
    }

SHELLEXECUTEINFO sei = { sizeof(sei) };