C + + essay: The Coreconsole of CORLECLR core exploration of. NET CoreCLR (2)

This article is the sequel to the previous article, this article will continue to introduce the logic inside Coreconsole.cpp. Perhaps people will read some of the CLR's books, I admit I have not seen, because I think a person, he again NB, that is his own vision, and to say the ugly, the CLR is not the person who wrote the book a person to complete the project, so his vision, I personally see, is still very limited.

To undertake the hostenvironment of the previous article, the host environment: the individual considers the host to refer to the Windows kernel. But the CLR has a drawback, is that it is not a cross-platform, so the broad sense that the host should be "operating system kernel"; Let's take a look at loadcoreclr this method, the core purpose of this method is to get the CLR from the dynamic link library, if the error, will be recorded log;

Try to "load" the CoreCLR with a CoreCLR path hmodule tryloadcoreclr (const wchar_t* directorypath) {//coreclr path wchar_t core The clrpath[max_longpath];//assigns the formal parameter to the argument, which is equivalent to coreclrpath= directorypath wcscpy_s (Coreclrpath, directorypath);// Take Coreclrdll,append to the back of CORECLRPATHD and make up a new string wcscat_s (Coreclrpath, Coreclrdll);//Logging start: Attempt to load coreclr *m_lo from the path        G << W ("Attempting to load:") << Coreclrpath << Logger::endl;//loadlibraryex mount the specified dynamic-link library. hmodule result =:: Loadlibraryexw (Coreclrpath, NULL, 0);//When loading fails, log if (!result) {*m_log << W (            "Failed to load:") << Coreclrpath << Logger::endl;            *m_log << W ("Error Code:") << GetLastError () << Logger::endl;        return nullptr; }//Pin The Module-coreclr.dll does not a support being UNLOADED.//GETMODULEHANDLEEXW is a module handle that gets an application or dynamic link library H Module dummy_coreclrmodule;//If it is get_module_handle_ex_flag_pin, then it is mapped in the process that called the function until the process ends if (!::getmodulehandleexw (Get_module_handle_ex_flag_pin, Coreclrpath, &dummy_coreclrmodule))            {*m_log << W ("Failed to pin:") << Coreclrpath << Logger::endl;        return nullptr;        } wchar_t Coreclrloadedpath[max_longpath];        :: Getmodulefilenamew (Result, Coreclrloadedpath, Max_longpath);    *m_log << W ("Loaded:") << Coreclrloadedpath << logger::endl;//return dynamic link library return result; }

The following is the constructor of Hostenvironment, and the main function of the individual is to initialize and load the CORECLR.

Public://path to the directory of that CoreCLR is IN//CORECLR, note the difference between "module path" and this path wchar_t M_coreclrdirectorypath [max_longpath];//the constructor with the log parameter and initialize the log and CLR runtime hostenvironment (Logger *logger): M_log (Logger), M_clrruntimehost ( NULLPTR) {//Discover the path to this EXE ' s module. All other files is expected to being in the same directory.//gets the length of the path of the EXE module in the directory DWORD thismodulelength =:: Getmodul            Efilenamew (:: Getmodulehandlew (nullptr), M_hostpath, Max_longpath);            Search for the final backslash in the host path.//find the last delimiter in the path "\ \", if found, jump out of the loop int lastbackslashindex; for (Lastbackslashindex = thisModuleLength-1; lastbackslashindex >= 0; lastbackslashindex--) {i                F (m_hostpath[lastbackslashindex] = = W (' \ \ ')) {break; }}//Copy the directory path//with M_hostdirectorypath instead of the previous path directory address:: wcsncpy_s (M_hostdirect Orypath, M_hostpath, Lastbackslashindex + 1);            Save the EXE name//host the name of the EXE file, similar to the file name, but here I have a question://m_hostpath is a character-type pointer, and lastbackslashindex+1 is a number, put them 2 what is the meaning of adding up?            M_hostexename = M_hostpath + lastbackslashindex + 1;            *m_log << W ("Host directory:") << M_hostdirectorypath << Logger::endl;            Check for%core_root% and try-to-load CoreCLR.dll from the IT if it is set//attempt to load coreclr//coreroot environment variables from the environment variable%core_root% real path            wchar_t Coreroot[max_longpath]; size_t outsize;//If the Tryloadcoreclr method is not used, then the constructor is used to initialize coreclr.m_coreclrmodule = NULL; Initialize This here since we don't call tryloadcoreclr if Core_root is unset.//take the value of the environment variable if (_wgetenv_s (& Outsize, Coreroot, Max_longpath, W ("Core_root")) = = 0 && outsize > 0) {wcscat_s (CORE                Root, Max_longpath, W ("\ \"));            M_coreclrmodule = TRYLOADCORECLR (coreroot); } else {*m_log << W ("Core_root not SEt                Skipping ") << Logger::endl;                *m_log << W ("You can set the environment variable core_root to point to the path") << Logger::endl;            *m_log << W ("where CoreCLR.dll lives to help this executable find it.") << Logger::endl;            }//try to load CoreCLR from the directory, the This exexutable is in//try loading CoreCLR from the catalog.            if (!m_coreclrmodule) {m_coreclrmodule = TRYLOADCORECLR (M_hostdirectorypath);                 }//effect Ditto (thismodulelength) if (m_coreclrmodule) {//Save the directory that CoreCLR is found in                DWORD modulepathlength =:: Getmodulefilenamew (M_coreclrmodule, M_coreclrdirectorypath, Max_longpath);                Search for the last backslash and terminate it there to keep just the directory path with trailing slash               for (Lastbackslashindex = modulePathLength-1; lastbackslashindex >= 0; lastbackslashindex--) {     if (m_coreclrdirectorypath[lastbackslashindex] = = W (' \ \ ')) {M_CORECLRDIRECTORYPATH[LASTBACKSL                        Ashindex + 1] = W (' n ');                    Break }}} else {*m_log << W ("Unable to load") << Coreclrdll << Lo            Gger::endl; }}//destructor, releasing CoreCLR ~hostenvironment () {if (m_coreclrmodule) {//Free the module. This is do for completeness, but the fact CoreCLR.dll//was pinned earlier so this call won ' t actually free It.            The pinning is//do because CoreCLR does not a support unloading.        :: FreeLibrary (M_coreclrmodule); }    }

The following is a list of the contents of the TPA to determine whether there are included files, the specific role is unknown.

If each item in the TPA list contains a file, at least one of which contains the file, then return true//filenamewithoutextension: The filename//rgtpaextensions:tpa suffix without the suffix, note that this is a pointer to a pointer. Countextensions: Number of suffixes bool Tpalistcontainsfile (wchar_t* filenamewithoutextension, wchar_t** rgTPAExtensions, int        Countextensions) {if (!m_tpalist.cstr ()) return false;//returns the false//loop suffix directly if the assembly path is empty. for (int iextension = 0; iextension < countextensions; iextension++) {wchar_t Filename[max_longpath] ;/So, we don't match other files, and the current file name//does not match the end of the other (compared to the filename) wcscpy_s (Filena Me, Max_longpath, W ("\ \"));            wcscat_s function, add the third parameter to the end of the first argument wcscat_s (FileName, Max_longpath, filenamewithoutextension);            wcscat_s (FileName, Max_longpath, rgtpaextensions[iextension] + 1); wcscat_s (FileName, Max_longpath, W (";")); So, we don ' t match other files this begin with the current file name//similar to.         NET contains if (Wcsstr (M_tpalist.cstr (), fileName) {       return true;    }} return false; }

The following method is to remove the file suffix, which should be a tool class

Remove file suffix    void Removeextensionandni (wchar_t* fileName)    {        //Remove extension, if it exists//if the file has a suffix, then long removed        wchar_t* Extension = WCSRCHR (FileName, W ('. '));         if (extension! = NULL)        {            extension[0] = W (' n ');            Check for. ni//detects. ni files, this kind of file, I did not check the online            size_t len = wcslen (fileName);            if (Len > 3 &&                filename[len-1] = = W (' i ') &&                filename[len-2] = = W (' n ') &&                fil Ename[len-3] = = W ('. '))            {//end character, equivalent. NET                filename[len-3] = W (' substring ');}}}    

The following 2 methods are all loading files into tpalist.

    Returns the semicolon-separated List of paths to runtime DLLs that is considered trusted. On first calling, scans the CORECLR directory for DLLs and adds them all to the list.//returns a list of trusted and semicolon-delimited lists to the runtime//At the time of the initial call, searching for CO RECLR all DLLs inside the directory and add them to tpalist to go to const wchar_t * Gettpalist () {if (!m_tpalist.cstr ()) {///file suffix collection Wcha  r_t *rgtpaextensions[] = {//Probe for. Ni.dll first so it's preferred if NI and il coexist in the same dir//                        *.ni.dll files, NI and Il will have a priority problem W ("*.ni.dll"), W ("*.dll"),            W ("*.ni.exe"), W ("*.exe"),}; Add files from%core_libraries% if specified//loads the file from the%core_libraries% environment variable, if this environment variable is set wchar_t Corelibraries[ma            X_longpath];            size_t outsize;            if (_wgetenv_s (&outsize, Corelibraries, Max_longpath, W ("core_libraries")) = = = 0 && outsize > 0) {wcscat_s (cOrelibraries, Max_longpath, W ("\ \"));            Addfilesfromdirectorytotpalist (Corelibraries, Rgtpaextensions, _countof (rgtpaextensions)); } else {*m_log << W ("Core_libraries not set;                Skipping ") << Logger::endl;                *m_log << W ("You can set the environment variable core_libraries to point to a") << Logger::endl;            *m_log << W ("Path containing additional platform assemblies,") << Logger::endl; }//loading files from the directory into Tpalist addfilesfromdirectorytotpalist (M_coreclrdirectorypath, Rgtpaextensions, _countof (rgTPAExte        Nsions)); } return M_tpalist.cstr ();    return to Tpalist; }

Today is the point here, the next one with you notice, will be the third introduction of GC to write out ~ ~ ~ ~ ~ ~ ~ ~ ~ ~

C + + essay: The Coreconsole of CORLECLR core exploration of. NET CoreCLR (2)