Tiny C run-time startup module for console applications

[Vortex]

Hi friends,

Here, you can find a tiny C run-time startup module with asm command line parser for various C/C++ compilers ( including Pelle's compiler )

Pelle, could you add the attachment feature to the forum?

Thanks,

Vortex

[TBD]

Vortex: where is crtdll.lib ?  

[Vortex]

Hi TBD,

Yes, you are right. Here is the solution:

Build.bat

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call povars32.bat
polib /machine:ix86 /out:crtdll.lib /def:crtdll.def

\pellesc\bin\pocc /Zx /Ze /Zl /Os Test.c
\pellesc\bin\polink /SUBSYSTEM:CONSOLE /OUT:Test.exe ..\startc.obj Test.obj ..\ParseCmdLine.obj kernel32.lib crtdll.lib


crtdll.def

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LIBRARY crtdll
EXPORTS
printf

...which normally is enough for this small example.

If you would like to get the zip file,y ou can send me a PM with your e.mail address.

[TBD]

thanks Vortex.

I created the lib myself using podump.exe /exports, removing the extra, adding LIBRARY crtdll, EXPORTS.

[Vortex]

Here is the attachment.

[Vortex]

Here is the startup module for GUI applications.

The code in C:

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#include <windows.h>

extern UINT WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow);

HMODULE hInstance;

void WINAPI WinMainCRTStartup()
{
hInstance=GetModuleHandle(NULL);
ExitProcess(WinMain(hInstance,NULL,GetCommandLine(),SW_SHOWDEFAULT));
}


The equivalent code in asm with some manual optimizations, wcrt0.asm :

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[cpu 486]
[global _WinMainCRTStartup]
[section .text]
[function _WinMainCRTStartup]
_WinMainCRTStartup:
push dword (0)
call dword [(__imp__GetModuleHandleA@4)]
mov dword [(_hInstance)],eax
call dword [(__imp__GetCommandLineA@0)]
push dword 10
push dword eax
push dword (0)
push dword [(_hInstance)]
call _WinMain@16
push dword eax
call dword [(__imp__ExitProcess@4)]
..?X_WinMainCRTStartup:
[section .bss]
[global _hInstance]
[common _hInstance 4]
[extern _WinMain@16]
[extern __imp__GetCommandLineA@0]
[extern __imp__GetModuleHandleA@4]
[extern __imp__ExitProcess@4]


No need to use an external assembler to generate the object code.
An example of building a GUI based application:

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call "povars32.bat"
pocc wcrt0.asm
pocc /Ze /Zl /Os Window.c
polink /SUBSYSTEM:WINDOWS /OUT:Window.exe wcrt0.obj Window.obj kernel32.lib user32.lib


The attachment contains a demo using this tiny C run-time startup code, the size of the final executable - a simple window is only 2048 bytes.

Click here to download the attachment.

[Vortex]

Bug fixed : The lpCmdLine parameter should point the first command line parameter not the filename.

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[cpu 486]
[global _WinMainCRTStartup]
[section .text]
[function _WinMainCRTStartup]
_WinMainCRTStartup:
push dword (0)
call dword [(__imp__GetModuleHandleA@4)]
mov dword [(_hInstance)],eax
call dword [(__imp__GetCommandLineA@0)]
dec eax
@100:
inc eax
mov cl,byte [eax]
or cl,cl
jz @102
cmp cl,32
jne @100
dec eax
@101:
inc eax
mov cl,byte [eax]
cmp cl,32
je @101
@102:
push dword 10
push dword eax
push dword (0)
push dword [(_hInstance)]
call _WinMain@16
push dword eax
call dword [(__imp__ExitProcess@4)]
..?X_WinMainCRTStartup:
[section .bss]
[global _hInstance]
[common _hInstance 4]
[extern _WinMain@16]
[extern __imp__GetCommandLineA@0]
[extern __imp__GetModuleHandleA@4]
[extern __imp__ExitProcess@4]


New attachment uploaded at the top.

[Jibz]

Nice work vortex .

I am not quite sure, but I think that code might fail if the filename or path at the start of the string returned by GetCommandLine contains spaces?

[Vortex]

Hi Jibz,

GetCommandLine removes those leading spaces, so there is no problem.

[Jibz]

What I meant was that if the filename of the executable itself contains spaces, then GetCommandLine will return something like:

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"C:\Foo\With Space.exe" arg1 arg2
where the filename with path is quoted because it contains a space.

Try in your example to show the contents of lpCmdLine in a messagebox, and then rename the executable to something with a space.

[Vortex]

Hi Jibz,

Thanks for pointing me the right direction.

Here is the code:

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[cpu 486]
[global _WinMainCRTStartup]
[section .text]

[function _WinMainCRTStartup]

_WinMainCRTStartup:
push dword (0)
call dword [(__imp__GetModuleHandleA@4)]
mov dword [(_hInstance)],eax
call dword [(__imp__GetCommandLineA@0)]
cmp byte [eax],34 ;check for leading quote
jne @102
@100: ;look for the second quote
inc eax
mov cl,byte [eax]
or cl,cl
jz @104
cmp cl,34
jne @100
jmp @103 ;look for space chars
@101:
inc eax
@102: ;skip file name
mov cl,byte [eax]
or cl,cl
jz @104
cmp cl,32
jne @101
dec eax
@103: ;skip space chars
inc eax
mov cl,byte [eax]
cmp cl,32
je @103
@104:
push dword 10
push dword eax
push dword (0)
push dword [(_hInstance)]
call _WinMain@16
push dword eax
call dword [(__imp__ExitProcess@4)]

..?X_WinMainCRTStartup:

[section .bss]
[global _hInstance]
[common _hInstance 4]
[extern _WinMain@16]
[extern __imp__GetCommandLineA@0]
[extern __imp__GetModuleHandleA@4]
[extern __imp__ExitProcess@4]


[TimoVJL]

Project file for WCRT0:

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#
# PROJECT FILE generated by "Pelles C for Windows, version 2.80".
# NOTE! Manual changes of this file is done at your own risk.
#

POC_PROJECT_VERSION = 1.00#
POC_PROJECT_TYPE = 2#
POC_PROJECT_PATH = .#
POC_PROJECT_ARGUMENTS = #
POC_PROJECT_WORKPATH = #
POC_PROJECT_EXECUTOR = #
CC = pocc.exe#
AS = pocc.exe#
AR = polib.exe#
CCFLAGS = #
ASFLAGS = #
ARFLAGS = #

.SILENT:  

#
# Build WCRT0.LIB.
#
"$(POC_PROJECT_PATH)\WCRT0.LIB": \
 "$(POC_PROJECT_PATH)\output\wcrt0.OBJ"
 $(AR) $(ARFLAGS) -out:"$@" $**

#
# Build wcrt0.OBJ.
#
"$(POC_PROJECT_PATH)\output\wcrt0.OBJ": \
 "$(POC_PROJECT_PATH)\wcrt0.asm"  
 $(AS) $(ASFLAGS) -Fo"$@" "$!"


Then you can use it in source file with

#pragma nodefaultlib
#pragma comment(lib, "wcrt0.lib")

[Vortex]

Hi timovjl,

That's nice, I will try it.  

[Vortex]

Here is another example using Pelle's C run-time DLL pocrt.dll

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#define WIN32_LEAN_AND_MEAN
#define IDC_EDIT 4001

#include <stdio.h>
#include <windows.h>

HINSTANCE hInstance;
FILE *file;
char buffer[75];
char k;
char i=0;

BOOL CALLBACK DlgProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
  switch(msg)
   {
       case WM_CLOSE:
EndDialog(hwnd,0);
       break;
       case WM_INITDIALOG:
file=fopen("Text.txt","r");

while ( k=fgetc(file)) {
if (k==EOF) {
buffer[i]=0;
break;
}

if (k==10) {
buffer[i]=13;
++i;
}

buffer[i]=k;
++i;
}
fclose(file);
SetDlgItemText(hwnd,(int)IDC_EDIT,buffer);
      break;
default:
           return FALSE;
   }
   return TRUE;

}

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,LPSTR lpCmdLine, int nCmdShow)
{
LPCTSTR DlgName="MyDialog";
hInstance=GetModuleHandle(0);
return(DialogBoxParam(hInstance,DlgName,0,DlgProc,0));
}
[/code]

[Vortex]

Hi friends,

Here is the latest release of my C startup code very easy to use, now this time the sample projects both GUI and console are supported with ppj files. The startup codes are assembler with Masm.