Avoiding _memset?
in [Visual C]
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From: Vincent Fatica on 7 Sep 2009 10:41 On Mon, 07 Sep 2009 09:26:25 +0200, Ulrich Eckhardt <eckhardt(a)satorlaser.com> wrote: |How about this: | | char simem[sizeof (STARTUPINFO)] = {0}; | STARTUPINFO si = (STARTUPINFO*)simem; Did you mean char simem[sizeof (STARTUPINFO)] = {0}; STARTUPINFO *psi = (STARTUPINFO*)simem; That invokes memset, gives the LNK4210 warning, makes a .CRT section, and increases the .text segment from 0x9F bytes to 0x9AA bytes (159 to 2474). SecureZeroMemory and __stosb avoid memset. So does STARTUPINFO si = {sizeof(si),0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}; but that costs about 64 bytes later, moving 0 into each member. -- - Vince
From: Vincent Fatica on 7 Sep 2009 10:50 On Mon, 7 Sep 2009 13:56:46 +0800, "xiaosi" <xiaosi(a)cn99.com> wrote: |"Vincent Fatica" <vince(a)blackholespam.net> wrote: |> while ( *pCmdLine && *pCmdLine != L' ' ) |> pCmdLine += 1; |> pCmdLine += 1; | |The above codes work when there's only one space between argv[0] and argv[1]. |If there's more than one space or tab, the above codes should change to: | while ( *pCmdLine && *pCmdLine <= L' ' ) | pCmdLine += 1; Thanks for pointing that out! Whenever I want to get a pointer to the tail (essentially from argv[1] on) of a command line I find myself writing some kludgy little routine like the one above. Is there an easier/canned/customary way (with/without the RTL)? -- - Vince
From: xiaosi on 7 Sep 2009 11:14 For avoiding crt, I once wrote my_get_command_line, which is borrowed from crt source codes (__tmainCRTStartup in VC\crt\src\crtexe.c): LPWSTR __stdcall my_get_command_line() { LPWSTR p = GetCommandLine(); BOOL inDoubleQuote = 0; while (*p > L' ' || (*p && inDoubleQuote)) { if (*p == L'\"') inDoubleQuote = !inDoubleQuote; p++; } while (*p && (*p <= L' ')) { p++; } return p; } This is not more concise than your codes. "Vincent Fatica" <vince(a)blackholespam.net> wrote: > On Mon, 7 Sep 2009 13:56:46 +0800, "xiaosi" <xiaosi(a)cn99.com> wrote: > > |"Vincent Fatica" <vince(a)blackholespam.net> wrote: > |> while ( *pCmdLine && *pCmdLine != L' ' ) > |> pCmdLine += 1; > |> pCmdLine += 1; > | > |The above codes work when there's only one space between argv[0] and argv[1]. > |If there's more than one space or tab, the above codes should change to: > | while ( *pCmdLine && *pCmdLine <= L' ' ) > | pCmdLine += 1; > > Thanks for pointing that out! > > Whenever I want to get a pointer to the tail (essentially from argv[1] on) of a > command line I find myself writing some kludgy little routine like the one > above. Is there an easier/canned/customary way (with/without the RTL)? > -- > - Vince
From: Vincent Fatica on 7 Sep 2009 12:47 On Mon, 7 Sep 2009 23:14:15 +0800, "xiaosi" <xiaosi(a)cn99.com> wrote: |For avoiding crt, I once wrote my_get_command_line, which is borrowed from crt source codes (__tmainCRTStartup in |VC\crt\src\crtexe.c): Thanks for that. After grep-ing through an archive of projects for "BOOL bInQuotes" I'm embarrassed to admit how many times I have done something similar. :-) Have you got any other tips on avoiding the RTL? wsprintf() is invaluable as are the lstr* functions (now I've learned that some of the wcs* functions have intrinsic/inline versions). I have often wanted something to turn a string into a number. If I insist on avoiding the RTL, I use StrToIntEx and feel a bit guilty dragging in shlwapi.dll for only that reason. -- - Vince
From: Alex Blekhman on 7 Sep 2009 14:44
"Vincent Fatica" wrote: > Mine is an utterly simple program (below). Without going out of > my way at all, I apparently get the intrinsic wcslen() (no > library, no warming, no .CRT section). memset() is another > story! > > #include <windows.h> > #include <intrin.h> > > INT MyWinMain(VOID) > { > [...] Even if you use a custom entry point it is still must conform to the expected signature of [w]WinMain or [w]main. Also, calling convention must be __stdcall for Windows subsystem and __cdecl for console subsystem. Alex |